WO2021079835A1

WO2021079835A1 - Electric vehicle, control method for same, and control program for same

Info

Publication number: WO2021079835A1
Application number: PCT/JP2020/039154
Authority: WO
Inventors: 浩明橋本
Original assignee: ナブテスコ株式会社
Priority date: 2019-10-24
Filing date: 2020-10-16
Publication date: 2021-04-29
Also published as: EP4049646A1; CN114466637A; JPWO2021079835A1

Abstract

Provided is an electric vehicle capable of detecting contact with a step with high accuracy and achieving an operation intended by a user.　This electric vehicle comprises: a drive unit that drives a wheel including at least any one among a front wheel and a rear wheel; a control unit that controls the drive unit and performs a control of climbing over a step; a measurement unit that measures at least any one among a velocity or an acceleration applied to a vehicle body provided with the wheel; and a determination unit that determines whether to perform the control of climbing over a step on the basis of the measurement value from the measurement unit.

Description

Electric vehicle, its control method, and its control program

The present disclosure relates to an electric vehicle for assisting the walking of elderly people, physically handicapped persons, inpatients and other persons with walking restrictions, a control method thereof, and a control program thereof.

Conventionally, walkers (silver cars, wheelbarrows) that assist the elderly going out, walkers and other walking assist devices have been used to assist the walking of physically handicapped persons or inpatients. For example, Patent Document 1 discloses a walking assist device capable of allowing the front wheels to ride on a step without performing an operation that imposes a heavy burden on the user.

In Patent Document 1, a frame, front wheels and rear wheels provided on the frame, a drive unit that generates a driving force that causes the front wheels to float with respect to the rear wheels, and a control that is connected to the drive unit and controls the drive unit. When the user determines that the front wheels have collided with a step even though the user is trying to move the electric vehicle forward, the control unit controls the drive unit to lift the front wheels with respect to the rear wheels. A walking assist device (electric vehicle) characterized by being able to perform is disclosed.

JP-A-2018-61819

In such a conventional walking assist device, there is a limitation in the accuracy of detecting contact with a step, and sufficient fine control is not performed, so that the operation of overcoming the step intended by the user may not be realized. For example, the step detection function and the step overcoming function of the conventional walking assist device are based on the premise that the walking assist device enters from almost the front (almost perpendicular direction) to the step. Therefore, when the right front wheel and the left front wheel of the walking assist device come into contact with the step with a time difference, it is difficult to get over the step. In addition, in order to accurately determine the necessity for the walking assist device to overcome the step, contact with the step, stop operation of the walking assist device by the user, and contact of the walking assist device with an object other than the step. It is necessary to identify the difference from the case where.

The present disclosure provides an electric vehicle, a control method thereof, and a control program thereof, which can detect contact with a step with high accuracy and realize an operation intended by a user.

In the electric vehicle according to the present disclosure, the drive unit for driving the wheels including at least one of the front wheels and the rear wheels provided on the vehicle body and the drive unit for overcoming the step for causing the wheels to get over the step are performed on the drive unit. Whether or not to let the control unit control the step over based on the control unit, the measurement unit that measures at least one of the speed or the acceleration applied to the vehicle body on which the wheel is provided, and the measurement value of the measurement unit. It is characterized by having a judgment unit for making a judgment.

In the electric vehicle according to the present disclosure, the determination unit may determine that the determination unit performs overcoming control of the step when it is estimated that the front wheel has come into contact with the step based on the measured value of the measurement unit.

In the electric vehicle according to the present disclosure, the step overcoming control may include a control for increasing the driving force for driving the wheels of the driving unit.

In the electric vehicle according to the present disclosure, the control for overcoming the step may include the control for turning the vehicle body.

In the electric vehicle according to the present disclosure, the control for overcoming the step may include a control for increasing the driving force while turning the vehicle body.

In the electric vehicle according to the present disclosure, the front wheels include a left front wheel and a right front wheel that are arranged apart from each other in the width direction of the vehicle body, and the determination unit determines the left front wheel or the right based on the measured values of the measurement unit. It may be estimated which of the front wheels touches the step.

In the electric vehicle according to the present disclosure, the measuring unit may measure at least one of the acceleration in the direction of decelerating the vehicle body or the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body.

In the electric vehicle according to the present disclosure, the rear wheels include a left rear wheel and a right rear wheel that are arranged apart from each other in the width direction of the vehicle body, and the measuring unit at least accelerates the left rear wheel in the rotational direction. And the average value of the acceleration in the rotation direction of the right rear wheel or the difference between the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel may be calculated.

In the electric vehicle according to the present disclosure, the measuring unit has at least the average value of the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel. The difference may be calculated.

In the electric vehicle according to the present disclosure, the measuring unit measures at least one of acceleration in the direction of decelerating the vehicle body and acceleration in the rear direction of the vehicle body and acceleration in the width direction of the vehicle body, and the determination unit. Is the left front wheel or the right front wheel when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rear direction of the vehicle body measured by the measuring unit becomes equal to or higher than the first threshold value. It may be estimated which of the two contacts the step.

In the electric vehicle according to the present disclosure, the measuring unit measures at least one of acceleration in the direction of decelerating the vehicle body and acceleration in the rear direction of the vehicle body and acceleration in the width direction of the vehicle body, and the determination unit. Was measured within a predetermined period after at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measuring unit became equal to or higher than the first threshold value. It may be estimated whether the left front wheel or the right front wheel comes into contact with the step when the maximum value of the absolute value of the acceleration in the width direction of the vehicle body becomes the second threshold value or more.

In the electric vehicle according to the present disclosure, the measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rear direction of the vehicle body, and the determining unit measures the acceleration of the measuring unit. The left front wheel and the right front wheel when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rear direction of the vehicle body becomes equal to or higher than a third threshold value smaller than the first threshold value. May be presumed to have come into contact with the step.

In the electric vehicle according to the present disclosure, the control unit generates a driving force only in the driving unit of the rear wheel located on the same side in the width direction of the vehicle body of the front wheel estimated to have come into contact with the step. May be good.

In the electric vehicle according to the present disclosure, the control unit is the driving unit of at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is presumed to have come into contact with the step. The driving force may be generated only in the direction.

In the electric vehicle according to the present disclosure, the control unit is the one of at least one of the front wheels on the side estimated to have come into contact with the step or the rear wheels located on the same side of the front wheels in the width direction of the vehicle body. A driving force larger than the driving force of the driving unit is applied to the driving unit of at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is estimated to have come into contact with the step. It may be generated.

In the electric vehicle according to the present disclosure, the control unit is the one of at least one of the front wheels on the side estimated to have come into contact with the step or the rear wheels located on the same side of the front wheels in the width direction of the vehicle body. Increase the driving force of at least one of the front wheels on the side estimated to be in contact with the step or the rear wheels located on the same side in the width direction of the vehicle body with respect to the driving force of the driving unit. You may.

In the electric vehicle according to the present disclosure, the control unit is a drive unit of at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is presumed to have come into contact with the step. The driving force and the driving force of the driving unit of at least one of the front wheels estimated to have come into contact with the step and the rear wheels located on the same side of the front wheels in the width direction of the vehicle body are defined as the fourth. It may be gradually increased until it reaches a threshold value.

In the electric vehicle according to the present disclosure, the driving force of at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is presumed to have come into contact with the step, is a driving force. It may be larger than the driving force of the driving unit of at least one of the front wheels and the rear wheels located on the same side of the front wheels in the width direction of the vehicle body, which are presumed to be in contact with the step.

In the electric vehicle according to the present disclosure, the control unit determines that both of the front wheels come into contact with the step based on the measured values of the measurement unit, and the front wheels are on both sides in the width direction of the vehicle body. Alternatively, the driving force of the driving unit of at least one of the front wheels or the rear wheels of the rear wheels may be equal.

In the electric vehicle according to the present disclosure, the control unit performs the overcoming operation of the step when the maximum value of the absolute value of the acceleration in the width direction of the vehicle body measured by the measurement unit becomes the second threshold value or more. The fifth threshold value of acceleration, which is a condition for executing, may be set small.

In the electric vehicle according to the present disclosure, the control unit has a sixth absolute value of acceleration, which is a condition for executing the overcoming operation of the step as the speed of the vehicle body measured by the measurement unit increases. The threshold value may be set large.

In the electric vehicle according to the present disclosure, the measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rear direction of the vehicle body, and the determining unit measures the acceleration measured by the measuring unit. It may be estimated that the front wheels come into contact with the step when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body is larger than the seventh threshold value.

In the electric vehicle according to the present disclosure, in the determination unit, at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or less than the seventh threshold value. In some cases, it is not necessary to presume that the front wheels have come into contact with the step.

In the electric vehicle according to the present disclosure, the measuring unit measures the frequency spectrum of the vibration of the vehicle body, and the determining unit measures the front wheel when the representative value of the measured value of the measuring unit is larger than the eighth threshold value. May be presumed to have come into contact with the step.

In the electric vehicle according to the present disclosure, the determination unit does not have to presume that the front wheel has come into contact with the step when the representative value of the value measured by the measurement unit is equal to or less than the eighth threshold value.

The electric vehicle according to the present disclosure includes a storage unit that stores the measured values of the measuring unit, and the determination unit may adjust the seventh threshold value based on the measured values stored in the storage unit. Good.

In the electric vehicle according to the present disclosure, the determination unit determines the seventh threshold value in a predetermined period before the control unit controls the front wheels to overcome the steps and then the control unit controls the front wheels to overcome the steps. If a smaller acceleration is detected, the seventh threshold value may be changed to a smaller value.

In the electric vehicle according to the present disclosure, the determination unit has the acceleration measured by the measurement unit when the control unit overcomes the step of the front wheel, which is larger than the seventh threshold value and the seventh threshold value. If the difference from is greater than a predetermined value, the seventh threshold value may be changed to a larger value.

In the electric vehicle according to the present disclosure, the vibration of the vehicle body may include vibration in the front-rear direction of the vehicle body.

The electric vehicle according to the present disclosure may be provided with a cushioning member that covers at least a part of the front surface of the vehicle body or both side surfaces in the width direction of the vehicle body.

In the electric vehicle according to the present disclosure, the front wheels may be twin-wheel casters configured to be able to turn.

The electric vehicle according to the present disclosure is added to a drive unit that drives wheels including at least one of front wheels and rear wheels, a control unit that controls the drive unit to control stepping over, and a vehicle body provided with the wheels. The control unit includes a measurement unit that measures at least one of speed and acceleration, and a determination unit that determines whether or not the control unit controls overcoming a step based on the measurement value of the measurement unit. When the determination unit determines that the front wheels have come into contact with a step based on the measured values of the measurement unit, the determination unit performs control to increase the driving force for driving the wheels of the drive unit or control to turn the vehicle body. It is a feature.

The method for controlling an electric vehicle according to the present disclosure determines whether or not to perform step overcoming control based on a step of measuring at least one of a speed or an acceleration applied to a vehicle body and at least one of the speed or the acceleration. It is characterized by including steps to be performed.

The method for controlling an electric vehicle according to the present disclosure includes a step of determining whether or not a front wheel has come into contact with a step based on at least one of the speed and the acceleration, and when it is estimated that the front wheel has come into contact with the step. The step of overcoming the step may be included.

In the control method of the electric vehicle according to the present disclosure, the step overcoming control is at least one of control for increasing the driving force for driving the wheels, control for turning the vehicle body, and control for increasing the driving force while turning the vehicle body. May include.

The control program for an electric vehicle according to the present disclosure determines whether or not the front wheels have come into contact with a step based on a step of measuring at least one of a speed or an acceleration applied to a vehicle body and at least one of the speed or the acceleration. It is characterized by including a step of performing the step and a step of controlling overcoming of the step when it is presumed that the front wheel has come into contact with the step.

In the control program of the electric vehicle according to the present disclosure, the step overcoming control is at least one of control for increasing the driving force for driving the wheels, control for turning the vehicle body, and control for increasing the driving force while turning the vehicle body. May include.

According to the present disclosure, it is possible to detect contact with a step with high accuracy and realize the operation intended by the user.

FIG. 1 is a perspective view showing an electrically assisted walking vehicle according to the first embodiment of the present disclosure. FIG. 2 is a side view showing an electrically assisted walking vehicle according to the first embodiment of the present disclosure. FIG. 3 is a schematic view showing a leg detection sensor. FIG. 4 is a schematic view showing a grip sensor. FIG. 5 is a schematic view showing a modified example of the grip sensor. FIG. 6 is a flowchart for explaining an example of the operation of the control unit. FIG. 7 is a graph showing a change in driving force with the passage of time after the front wheels collide with a step. FIG. 8 is a graph showing an example of acceleration and threshold value detected in each case of collision with a step and stop operation. FIG. 9 is a graph showing an example of the acceleration detected when colliding with a soft object and the acceleration detected when colliding with a step. FIG. 10 is a schematic view showing a configuration example in which a cushioning material is provided in front of the vehicle body. FIG. 11 is a plan view showing an example of acceleration applied to the vehicle body when the electrically assisted walking vehicle collides with a step. FIG. 12 is a graph showing the difference in acceleration detected by the front wheels that collide. FIG. 13 is a graph showing an example of acceleration detected in the case of turning approach and straight approach. FIG. 14 is a graph showing an example of a time waveform of acceleration measured at the time of collision with a step. FIG. 15 is a plan view showing a first example of an electrically power assisted walking vehicle approaching a step at an angle. FIG. 16 is a plan view showing a second example of the electrically assisted walking vehicle approaching the step at an angle. FIG. 17 is a plan view showing a second example of the electrically assisted walking vehicle approaching the step at an angle. FIG. 18 is a graph showing an example of control for turning an electric vehicle after detecting contact with a step of one of the front wheels. FIG. 19 is a graph showing an example of control for turning an electric vehicle after detecting contact with a step of one of the front wheels. FIG. 20 is a plan view showing a first example when the front wheels have an angle with respect to the traveling direction of the vehicle body. FIG. 21 is a plan view showing a second example in which the front wheels have an angle with respect to the traveling direction of the vehicle body. FIG. 22 is a plan view showing an example of a collision between an electrically power assisted walking vehicle and a step. FIG. 23 is a plan view showing an example of a collision between the electrically power assisted walking vehicle and the step. FIG. 24 is a perspective view showing an electrically assisted walking vehicle according to a second embodiment of the present disclosure. FIG. 25 is a side view showing an electrically assisted walking vehicle according to a second embodiment of the present disclosure. FIG. 26 is a side view showing the configuration around the rear wheels of the electrically power assisted walking vehicle according to the second embodiment of the present disclosure. FIG. 27 is a cross-sectional view (FIG. XI-XI cross-sectional view of FIG. 25) showing a configuration around the rear wheels of the electrically power assisted walking vehicle according to the second embodiment of the present disclosure. FIG. 28 is a cross-sectional perspective view showing a configuration around the rear wheels of the electrically power assisted walking vehicle according to the second embodiment of the present disclosure. FIG. 29 is a schematic view (during normal driving) showing a modified example of the electrically assisted walking vehicle. FIG. 30 is a schematic view (when the front wheels are locked) showing a modified example of the electrically assisted walking vehicle. 31 (a) and 31 (b) are schematic views showing an electrically assisted walking vehicle according to a third embodiment of the present disclosure, respectively. 32 (a) and 32 (b) are schematic views showing an electrically assisted walking vehicle according to a modified example of the third embodiment of the present disclosure, respectively. FIG. 33 is a perspective view showing an electrically assisted walking vehicle according to a fourth embodiment of the present disclosure.

(First Embodiment)
First, the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 23. In the following, the same components are designated by the same reference numerals. Their names and functions shall be similar. The detailed description of the components with the same reference numerals will not be repeated.

1 and 2 are diagrams showing an electric walking vehicle (hereinafter, referred to as an electrically assisted walking vehicle) as an example of an electric vehicle. FIG. 1 is a schematic perspective view showing an example of the appearance of the electrically power assisted walking vehicle 10 according to the first embodiment, and FIG. 2 is a side view of the electrically power assisted walking vehicle 10 of FIG.

(Composition of electrically power assisted walking vehicle)
As shown in FIGS. 1 and 2, the electrically power assisted walking vehicle 10 is connected to the frame 11, a pair of front wheels (wheels) 12 and a pair of rear wheels (wheels) 13 provided on the frame 11, and the frame 11. It is provided with a pair of handles (operation unit) 14. Two pairs of rear wheels 13 are arranged apart from each other in the width direction of the vehicle body. Similarly, two pairs of front wheels 12 are arranged apart from each other in the width direction of the vehicle body. Hereinafter, the case where the electric vehicle is mainly a four-wheeled vehicle in which two front wheels and two rear wheels are arranged will be described as an example, but this configuration is only an example. For example, the electric vehicle may be a tricycle in which the vehicle body is provided with one front wheel and a pair of (two) rear wheels arranged two apart in the width direction of the vehicle body. Further, three or more front wheels may be arranged apart from each other in the width direction. The front wheel arranged on the rightmost side in the front direction of the vehicle body is called the right front wheel, and the front wheel arranged on the leftmost side in the front direction of the vehicle body is called the left front wheel. That is, the front wheels include a left front wheel and a right front wheel that are arranged apart from each other in the width direction of the vehicle body. Further, three or more rear wheels may be arranged apart in the width direction. The rear wheel arranged on the rightmost side in the front direction of the vehicle body is called the right rear wheel, and the rear wheel arranged on the leftmost side in the front direction of the vehicle body is called the left rear wheel. That is, the rear wheels include a left rear wheel and a right rear wheel that are arranged apart from each other in the width direction of the vehicle body. The number of wheels provided in the electric vehicle is not particularly limited. Therefore, the electric vehicle may have a different number of wheels than those described above.

Further, each handle 14 is provided with a brake unit 15 for manually stopping the electrically assisted walking vehicle 10. Hereinafter, the frame 11 and the structure supported by the frame 11 will be referred to as the “whole body of the electrically assisted walking vehicle 10”.

A motor 20 that assists the movement of the corresponding rear wheel 13 is connected to the pair of rear wheels 13. The electrically assisted walking vehicle may be connected to each of the front wheels 12 and may include a motor that assists the movement of each of the front wheels 12. Each front wheel 12 and each rear wheel 13 may be connected to the motor, or only the front wheel 12 may be connected to the motor. A battery 21 and a control unit 16 are attached to the frame 11, respectively.

Further, the control unit 16 is provided with an acceleration sensor 22a and a speed sensor 22b. Further, the handle 14 is provided with an inclination detection sensor 23 and a grip sensor (operating force sensor) 24, respectively. A leg detection sensor 25 for detecting the presence or absence of a user's leg is arranged on the frame 11 at a position below the pair of handles 14.

Next, each component of the electrically power assisted walking vehicle 10 will be further described.

The frame 11 has a pair of left and right pipe frames 31 and a connecting frame 32 that connects the pair of pipe frames 31 in the lateral direction.

A pair of front wheels 12 are provided on the front end side of each of the pair of left and right pipe frames 31. That is, two front wheels are arranged apart from each other in the width direction of the vehicle body of the electrically assisted walking vehicle 10. Of the pair of front wheels 12, the one on the R side is called the right front wheel, and the one on the L side is called the right front wheel to distinguish them. Each of the pair of front wheels 12 is rotatable in the front-rear direction and is also rotatably provided around a vertical axis.

Further, a pair of rear wheels 13 are provided on the rear end side of each of the pair of left and right pipe frames 31. Of the pair of rear wheels 13, the one on the R side is called the right rear wheel, and the one on the L side is called the right rear wheel to distinguish them. Each rear wheel 13 is provided so as to be rotatable in the front-rear direction. As a result, the electrically assisted walking vehicle 10 can be easily moved forward and backward, and can be easily moved or changed direction (turned) in the left-right direction.

Further, a brake shoe 33 that can be mechanically contacted is provided on the outer periphery of each rear wheel 13.
The brake shoe 33 is connected to the brake lever 34 of the brake unit 15 via a wire 35. Therefore, in response to the user manually operating the brake lever 34, the brake shoe 33 operates to brake the rear wheels 13. The mechanical brake configuration is not limited to this, and any configuration can be used.

Further, a fall prevention member 36 is provided from the rear end side of each of the pair of left and right pipe frames 31. The fall prevention member 36 prevents a pair of front wheels 12 of the electrically power assisted walking vehicle 10 from rising from the ground and falling backward.

A pair of handles 14 are provided at the upper ends of the pair of left and right pipe frames 31. The pair of handles 14 are each gripped by the user's hand. The pair of handles 14 have a rod-shaped member 41. Each rod-shaped member 41 is provided with a grip portion 42. Further, a brake lever 34 is attached to each of the rod-shaped members 41. The configuration of the handle 14 is not limited to this, and for example, a bar handle extending in the horizontal direction is provided so as to connect a pair of left and right pipe frames 31, and a grip portion 42 is provided as a pair of left and right handles 14 on this bar handle. May be good.

In the present embodiment, any motor such as a servo motor, a stepping motor, an AC motor, or a DC motor can be used as the motor 20. Further, the motor 20 integrally formed with the speed reducer may be used. The motor 20 assists the operation of the rear wheels 13 and drives the rear wheels 13 in the forward direction for traveling. Further, in the present embodiment, the motor 20 also serves as a driving unit that lifts the front wheels 12 with respect to the rear wheels 13. That is, the driving force of the motor 20 (driving unit) generates a moment in the direction of lifting the front wheels 12.

Further, the motor 20 may also have a function as a dynamic brake. In this case, the motor 20 further serves as a braking unit for braking the rear wheels 13. When the motor 20 brakes the rear wheels 13, the motor 20 is operated as a generator, and the brake is applied by the resistance force thereof. When the motor 20 serves as a braking unit, it may be used as a reverse brake that drives the motor 20 in the opposite direction. The braking portion that brakes the rear wheel 13 may be a component different from that of the motor 20. Examples of such a braking unit include an electromagnetic brake and a mechanical brake.

The left and right motors 20 may be controlled independently by the control unit 16. However, if it is not necessary to make a difference in speed or acceleration between the wheels on the right side of the vehicle body and the wheels on the left side of the vehicle body, the control unit 16 may control the motor 20 integrally on the left and right sides.

In the present embodiment, it is assumed that the motor 20 is connected to each of the rear wheels 13 (left rear wheel, right rear wheel). However, the configuration in which the same motor is connected to all of the pair of front wheels 12 and the pair of rear wheels 13 is not excluded.

The control unit 16 controls the drive unit (for example, the motor 20 described above) of the electrically assisted walking vehicle 10 to control overcoming a step. Here, the step overcoming control refers to the control for allowing the front wheels of the vehicle body to ride on the step. The determination unit 16a determines whether or not to perform step overcoming control based on the measured value of the measurement unit. For example, the determination unit 16a determines that the step overcoming control is performed when the front wheel 12 is estimated to have come into contact with the step based on the measured value of the measurement unit. Examples of the measuring unit include

acceleration sensors

22a, 81r to 82l and speed sensors 22b, which will be described later. For example, the measuring unit may measure at least one of acceleration in the direction of decelerating the vehicle body and acceleration in the front-rear direction of the vehicle body and acceleration in the width direction of the vehicle body. This makes it possible to determine whether the left front wheel or the right front wheel is in contact with the step (one-sided contact), or whether the left front wheel and the right front wheel are in contact with the step (both wheels are in contact).

For example, the control unit 16 and the determination unit 16a are provided in the vicinity of the battery 21. The control unit 16 and the determination unit 16a may include a processor capable of executing various instructions or programs. The control unit 16 and the determination unit 16a execute, for example, a control program of the electrically assisted walking vehicle 10 (electric vehicle). Further, the control unit 16 and the determination unit 16a may include hardware circuits such as ASIC, FPGA, and PLD. Further, the electrically assisted walking vehicle 10 may include a storage unit 16b. The control unit 16 and the determination unit 16a can read and write data to and from the storage unit 16b. Instructions, programs or instructions executed by the control unit 16 and the determination unit 16a, data used for executing the program, and measurement values of various sensors (measurement units) are stored in the storage unit 16b. The control unit 16 and the determination unit 16a may be mounted using a common hardware circuit. Further, the control unit 16 and the determination unit 16a may be implemented by using a common program. Further, the control unit 16 and the determination unit 16a may be implemented by separate hardware circuits or programs.

The step overcoming control performed by the drive unit may include control to increase the driving force for driving the wheels of the drive unit. Further, the step overcoming control may include a control for turning the vehicle body. The step overcoming control may include a control for increasing the driving force while turning the vehicle body. Details of the processing executed by the control unit 16 and the determination unit 16a will be described later.

The storage unit 16b provides a storage area capable of storing various types of data. The storage unit 16b may be provided in the vicinity of the control unit 16 or may be a part of the control unit 16. The storage unit 16b may be, for example, a volatile memory such as SRAM or DRAM, or a non-volatile memory such as NAND, MRAM, or FRAM. Further, it may be a storage device such as a hard disk or SSD, or an external storage device, and the type of device is not particularly limited. Further, the storage unit 16b may be a combination of a plurality of types of memory devices and storage devices.

The acceleration sensor 22a measures the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body. Here, the acceleration in the front-rear direction of the vehicle body means the acceleration in the direction FB of FIG. Further, the acceleration in the width direction of the vehicle body means the acceleration in the direction L and the direction R in FIG. As will be described later, the acceleration sensor 22a may measure the acceleration in the direction of decelerating the vehicle body in addition to the acceleration in the front-rear direction of the vehicle body. Further, the acceleration sensor 22a may measure the acceleration in the direction of decelerating the vehicle body instead of the acceleration in the front-rear direction of the vehicle body. The control unit 16 can acquire the acceleration measured by the acceleration sensor 22a. An example of a sensor that measures the acceleration applied to the vehicle body is a MEMS sensor or the like, but any kind of device may be used.

Further, a piezoelectric sensor, a strain gauge, an operating force sensor (for example, a grip sensor) or the like is used to measure the force applied to the component of either the electrically assisted walking vehicle 10 or the electrically assisted walking vehicle 10, and the estimated value of acceleration is obtained. You may ask.

The acceleration sensor may measure the acceleration in the rotation direction of each wheel of the electrically assisted walking vehicle 10. For example, the acceleration sensors 81r to 82l in FIG. 1 measure the acceleration in the rotational direction of each wheel. Specifically, the acceleration sensor 81r measures the acceleration of the right front wheel (front wheel 12 on the direction R side). The acceleration sensor 81l measures the acceleration of the right front wheel (front wheel 12 on the L side in the direction L). The acceleration sensor 82r measures the acceleration of the right rear wheel (rear wheel 13 on the direction R side). The acceleration sensor 82l measures the acceleration of the right rear wheel (rear wheel 13 on the L side in the direction L).

The acceleration sensors 81r to 82l may directly measure the acceleration of each wheel, or may measure the acceleration of the motor 20 and provide an estimated value of the wheel acceleration. Alternatively, the speed of the wheel or the motor 20 may be measured and an estimated value of acceleration may be calculated. Further, the number of revolutions of the wheel or the motor 20 per hour may be measured, the time derivative of the number of revolutions may be calculated, and the estimated value of acceleration may be obtained. The control unit 16 can acquire the acceleration measured by the acceleration sensors 81r to 82l.

The speed sensor 22b detects the rotation speed or speed of the rear wheel 13 and transmits a signal of this rotation speed or speed to the control unit 16. The speed sensor 22b can be installed, for example, in the vicinity of the control unit 16. The speed sensor 22b may be built in the pair of rear wheels 13 of the electrically power assisted walking vehicle 10. Alternatively, the speed sensor 22b may be built only inside the pair of front wheels 12, or may be built in all of the pair of front wheels 12 and the pair of rear wheels 13. An example of a speed sensor is a gyro sensor that measures an angular velocity. By using the gyro sensor, it is possible to detect which of the left and right wheels collides with an object such as a step.

When the motor 20 is a brushless motor, the speed sensor 22b may calculate the rotation speed or speed of the wheels and the speed of the electrically assisted walking vehicle 10 by using the Hall element built in the motor 20.

If the speed can be detected from the countercurrent force of the motor 20, the rotation speed or speed of the wheels and the speed of the electrically assisted walking vehicle 10 are calculated from the countercurrent force, and each rear wheel is configured. When the angular velocity of 13 or each of the front wheels 12 can be detected, it can be configured to calculate the number of rotations or speed of the wheels and the speed of the electrically assisted walking vehicle 10 from this angular velocity.

Further, the speed sensor 22b is not limited to being built in the pair of front wheels 12 and the pair of rear wheels 13, and may be attached to any other member such as the frame 11 and the pair of handles 14. Alternatively, the speed may be calculated by integrating the acceleration measured by the acceleration sensor. When GPS (Global Positioning System) is used, the speed may be calculated based on the displacement of the coordinates per time.

The speed sensor 22b and the acceleration sensors 81r to 82l may be used to measure the acceleration (negative acceleration) in the direction of decelerating the vehicle body. First, the traveling direction of the vehicle body is specified based on the measured value of the speed sensor 22b. Then, the direction of the acceleration measured by the acceleration sensors 81r to 82l is specified. When the direction of the measured acceleration includes a component in the direction opposite to the traveling direction of the vehicle body, the acceleration of the component can be the acceleration in the direction of decelerating the vehicle body.

The tilt detection sensor 23 detects the tilt of the electrically assisted walking vehicle 10, for example, whether the electrically assisted walking vehicle 10 is on a flat surface or an inclined surface, and determines a signal relating to the tilt of the electrically assisted walking vehicle 10 in the determination unit 16a. Send to. The determination unit 16a may estimate whether or not the electrically assisted walking vehicle 10 has succeeded in getting over the step based on the measured value of the inclination sensor 23. The tilt detection sensor 23 is provided on the upper part of the electrically assisted walking vehicle 10, for example, inside a pair of handles 14. The tilt detection sensor 23 can be provided at the lower part of the electrically assisted walking vehicle 10, but by arranging the tilt detection sensor 23 at the upper part, the posture of the electrically assisted walking vehicle 10 can be reliably detected as compared with the case where the tilt detection sensor 23 is arranged at the lower part. A gyro sensor may be used as the tilt detection sensor 23. Further, the inclination of the electrically assisted walking vehicle 10 may be detected by using the acceleration sensor.

FIG. 3 is a schematic view showing an example of the leg detection sensor 25. As shown in FIG. 3, the leg detection sensor 25 is provided on the connecting frame 32. Examples of the leg detection sensor 25 include an image sensor, an infrared sensor, and the like. The leg detection sensor 25 can detect the movement of the leg by measuring the distance from the leg of the user of the electrically assisted walking vehicle 10.

Specifically, the leg detection sensor 25 in FIG. 3 faces backwards depending on whether the user's leg is moving, stopped, away, or approaching in the range AR. It is possible to determine whether or not the person is trying to sit on the seat surface 37.

4 and 5 are schematic views for explaining the grip sensor 24.

The grip portions 42 of the pair of handles 14 are provided with grip sensors 24 that detect the operating force (grip force) that the user manually pushes or pulls the electrically assisted walking vehicle 10. The grip sensor 24 is regulated by an elastic member (for example, a spring) (for example, a spring) whose movement in one or both of the pushing direction and the pulling direction with respect to the rod-shaped member 41 is not shown, and further includes a potentiometer for detecting the movement. There is.

As described above, the grip portion 42 can move in the front-rear direction with respect to the rod-shaped member 41, and when it moves in the direction of the arrows (forward direction) in FIGS. 4 and 5, the electrically assisted walking vehicle 10 is moved by the user. When it can be determined that is pressed and the vehicle moves in the opposite direction (rear direction) of the arrows in FIGS. 4 and 5, it can be determined that the electrically power assisted walking vehicle 10 is being pulled by the user, and in either direction. If it has not moved, it can be determined that it is neither of them.

As a result, whether the user is trying to move the electrically assisted walking vehicle 10 forward or the user is trying to move the electrically assisted walking vehicle 10 backward, the user is informed of the state of the electrically assisted walking vehicle 10. It is possible to recognize whether there is an intention to change it.

The pair of left and right handles 14 are provided with separate grip sensors 24. Each grip sensor 24 independently detects an operating force (grip force) with respect to the handle 14, and transmits the detected operating force to at least one of the control unit 16 and the determination unit 16a. Therefore, at least one of the control unit 16 and the determination unit 16a is gripped by the user only on one of the pair of handles 14 (one-handed holding state), or neither of the pair of handles 14 is gripped (in a one-handed state). It is possible to recognize whether the two-handed state is released) or whether both of the pair of handles 14 are gripped (both-handed state).

As shown in FIG. 5, a strain sensor 38 (for example, a strain gauge) is provided in the grip portion 42 so that the moment applied to the grip portion 42 or the pair of pipe frames 31 can be detected, and this can also be used as the grip sensor 24. Good. In this case, since the grip portion 42 is fixed to the rod-shaped member 41, the configuration can be simplified. Further, the grip portion 42 may be provided with a proximity sensor for detecting a joystick, a push button, or a user's hand, and this may be used as the grip sensor 24. That is, in order to "determine that the user is trying to advance the electric vehicle through the operation unit (the user is performing the forward operation of the electric vehicle)", the user is a part of the hand or body. In addition to the case where the user's operating force applied to the operation unit is detected by pushing or pulling the operation unit with, the case where the user's operation is detected by a switch means such as a joystick or a push button is included.

(Overview of electrically power assisted walking vehicle)
The electrically assisted walking vehicle 10 (electric vehicle) has a drive unit that drives a wheel including at least one of the front wheels or the rear wheels provided on the vehicle body, and the drive unit that controls the step overcoming of the wheel to get over the step. It is determined whether or not to perform step overcoming control based on the control unit 16 to be performed, the measurement unit that measures at least one of the speed or acceleration applied to the vehicle body on which the wheels are provided, and the measurement value of the measurement unit. It is provided with a determination unit 16a. The control unit of the electrically power assisted walking vehicle 10 controls to increase the driving force for driving the wheels of the drive unit or turns the vehicle body when the determination unit 16a determines that the front wheels have come into contact with the step based on the measured value of the measurement unit. Control may be performed. As a result, the electrically assisted walking vehicle 10 can detect a collision (contact) with the step and determine the mode of contact with the step. In addition, the electrically power assisted walking vehicle 10 can perform an operation of overcoming a step having an appropriate content at an appropriate timing.

In the following, a case where the control unit 16 transmits a command based on the step overcoming control algorithm to the drive unit and the drive unit operates will be described as an example. However, the processing assignment in each component may be different. For example, the control unit 16 may transmit a step overcoming control start command to the driving unit, and the driving unit may start an operation based on the step overcoming control algorithm set in itself.

Based on the measured values (including at least one of the speed and acceleration) of the measuring unit, the determination unit 16a causes the electrically assisted walking vehicle to make contact with the step, stop operation by the user, and collide with an object other than the step. Distinguish. Further, the determination unit 16a can estimate the traveling direction of the electrically assisted walking vehicle with respect to the step (angle of the electrically assisted walking vehicle with respect to the step) based on the measured value.

When the control unit 16 detects contact with the step, the control unit 16 performs an operation of overcoming the step according to the traveling direction (angle) of the electrically assisted walking vehicle with respect to the estimated step. Examples of the step overcoming operation include turning of the vehicle body, assist by the drive unit connected to the front wheels, and combination of turning of the vehicle body and assist by the drive unit connected to the front wheels.

The control method of the electrically assisted walking vehicle (electric vehicle) includes a step of measuring at least one of the speed and acceleration applied to the vehicle body, a step of determining the presence or absence of a step based on at least one of the speed and acceleration, and the step of determining the presence or absence of a step. When it is determined that there is a step, the step of executing the step overcoming operation may be included.

Control of the electrically assisted walking vehicle (electric vehicle) may be realized by hardware such as a program, a processor, an electronic circuit, etc. mounted on the electrically assisted walking vehicle, or a combination thereof. Further, the electrically assisted walking vehicle may receive a wireless signal from the outside and be controlled based on the control signal transmitted from the external control device (information processing device).

(Action of the present embodiment)
Next, the operation of the present embodiment having the above-described configuration will be described. FIG. 6 is a flowchart for explaining an example of the operation of the control unit 16.

First, the control unit 16 determines whether or not the front wheel 12 has collided with the step while the user is operating the electrically assisted walking vehicle 10 forward. In this case, first, the control unit 16 has the left and right pair of handles 14 for a certain period of time or more (for example, 1 second or more) based on the signals detected by the grip sensors 24 provided on the left and right pair of handles 14, respectively. It is determined whether or not the button is pushed by the force of (step S101).

The control unit 16 uses the value of the change in the operating force (absolute value) in addition to the value of the operating force (absolute value), so that the handle 14 is pushed by the user's hand with a force equal to or higher than a certain level. It may be determined whether or not it is. In this case, it is possible to determine with higher accuracy whether or not the handle 14 is pushed by the user's hand with a force equal to or higher than a certain level. For example, when the absolute value of the operating force is equal to or less than a predetermined value and the absolute value of the change in the operating force (differential value of the operating force) is equal to or less than the predetermined value, the handle 14 is set to a certain value or more by the user's hand. It may be determined that the handle 14 is not pushed by a force, and in other cases, it may be determined that the handle 14 is pushed by a user's hand with a certain force or more. Further, when the operating force and the change in the operating force are within the elliptical region inscribed in the numerical range of the rectangle separated by each predetermined value, even if it is determined that the handle 14 is not gripped by the user's hand. Good. In this case, the determination can be made with higher accuracy.

Here, when the pair of handles 14 are not pushed by a certain force or more (No in step S101), it is determined that the user is not trying to move the electrically assisted walking vehicle 10 forward, and the following control is not performed. In this case, the control unit 16 may brake the rear wheels 13 by using the motor 20 as a dynamic brake.

On the other hand, when the pair of handles 14 are pushed with a certain force or more for a certain period of time or more (YES in step S101), the control unit 16 determines that the user is trying to move the electrically assisted walking vehicle 10 forward. Subsequently, the control unit 16 determines whether or not the front wheel 12 has collided with the step (step S102).

Specifically, the speed sensor 22b detects the rotation speed or speed of the rear wheel 13, and transmits a signal of this rotation speed or speed to the control unit 16. The control unit 16 calculates the speed of the rear wheels 13 based on the transmitted signal, and compares this speed with a predetermined speed (threshold value) V.

If the rear wheels 13 are driving, that is, if the rear wheels 13 are moving at a speed exceeding a predetermined speed V (YES in step S102), the control unit 16 is in a state where the electrically assisted walking vehicle 10 is in a normal state. It is determined that the vehicle is running, and the motor 20 continues to assist the movement of the rear wheels 13.

On the other hand, when the rotation of the rear wheel 13 is stopped and the speed is 0 (the movement of the electrically assisted walking vehicle 10 is stopped), or the vehicle is moving at a predetermined speed V or less (electrically assisted walking). When the traveling speed of the vehicle 10 is below a certain level (NO in step S102), the control unit 16 steps the electrically assisted walking vehicle based on the measured value (including at least one of the speed and the acceleration) of the measuring unit. It is estimated whether the vehicle collided with the vehicle, or whether any other event such as a stop operation by the user or a collision with an object other than the step occurred.

Further, when the control unit 16 determines that the electrically assisted walking vehicle has collided with the step (YES in step S103), the control unit 16 is based on the measured value (including at least one of the speed and the acceleration) of the measuring unit. The traveling direction (angle) of the electrically assisted walking vehicle with respect to the step is estimated (step S104). Then, the step overcoming operation is performed according to the traveling direction (angle) of the electrically assisted walking vehicle with respect to the estimated step (step S105). Examples of the step overcoming operation include turning of the vehicle body, assist by the drive unit connected to the front wheels, and combination of turning of the vehicle body and assist by the drive unit connected to the front wheels. The step climbing motion may include the motion of lifting the front wheel.

Details of the process in which the control unit 16 detects a collision with a step (step S103), the process of estimating the traveling direction of the electrically assisted walking vehicle with respect to the step (step S104), and the operation of overcoming various steps (step S105). Will be described later. As will be described later, in steps S103 to S105, the difference in control processing for the left and right components, the detected speed, and the direction of acceleration become important. The difference in control processing related to the left and right components will be described later, and an example of the operation of lifting the front wheels will be described below.

When performing the operation of lifting the front wheels, the control unit 16 controls the motor 20 (driving unit) to increase or decrease the driving force of the motor 20 according to, for example, the force pushing the handle 14 (the operating force applied to the handle 14). Since the front wheels 12 collide with the step and the electrically assisted walking vehicle 10 cannot move forward, the driving force in the forward direction of the rear wheels 13 causes the electrically assisted walking vehicle 10 to generate a moment in the direction of lifting the front wheels 12. Therefore, the front wheel 12 can be lifted with respect to the rear wheel 13.

When the control unit 16 determines that the user intends to move the electrically assisted walking vehicle 10 forward (intentionally to move forward), the control unit 16 determines the time and force at which the handle 14 is pressed as described above. By using it, it is possible to accurately judge that the user is trying to move forward and avoid a judgment that is different from the user's intention. As a result, the user can use the electrically assisted walking vehicle 10 with greater peace of mind. In making this determination, it is also possible to use only the force with which the handle 14 is pressed. For example, when the steering wheel 14 is pushed with a certain force or more, it is determined that the user is trying to move the electrically assisted walking vehicle 10 forward. In this case, the control unit 16 quickly determines that the user is about to move forward, and the user can lift the front wheel 12 without significantly reducing the walking speed.

The control unit 16 may use the acceleration of the rear wheels 13 in addition to the speed of the rear wheels 13 when determining whether or not the front wheels 12 have collided with the step. Thereby, it is possible to determine with higher accuracy whether or not the electrically assisted walking vehicle 10 is moving. For example, when the speed of the rear wheels 13 is equal to or less than a predetermined speed V and the acceleration of the rear wheels 13 is equal to or less than a predetermined acceleration, it is determined that the electrically assisted walking vehicle 10 has collided with a step, and in other cases. , It may be determined that the electrically assisted walking vehicle 10 does not collide with the step.

Alternatively, the control unit 16 decelerates the electrically assisted walking vehicle 10 (negative acceleration), that is, decelerates the rear wheels 13 (negative acceleration) while the speed of the rear wheels 13 is equal to or less than a predetermined speed V close to 0. ) Is equal to or higher than a predetermined threshold value, the front wheel 12 collides with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward (intentionally to move forward). It may be determined that it has been done. That is, when the speed of the rear wheels 13 becomes a value close to 0 and the deceleration of the rear wheels 13 becomes a certain value or more, it is considered that the front wheels 12 collide with the step and stop suddenly. In this case, it can be determined that the front wheel 12 has collided with the step without necessarily using the information from the grip sensor 24. Therefore, the electrically assisted walking vehicle 10 does not necessarily have to be provided with the grip sensor 24. The deceleration is a negative acceleration as described above, and the value becomes positive when the electrically assisted walking vehicle 10 is decelerating, and the value when the electrically assisted walking vehicle 10 is accelerating. Becomes negative.

Further, when the pair of handles 14 are pushed by a certain force or more for a certain period of time or more and the deceleration (negative acceleration) of the rear wheels 13 is equal to or more than a predetermined threshold value, the control unit 16 is electrically driven by the user. It may be determined that the front wheels 12 have collided with the step even though the assisted walking vehicle 10 is trying to move forward (intentionally to move forward). Thereby, it is possible to determine with high accuracy whether or not the electrically assisted walking vehicle 10 is moving. Whether or not the pair of handles 14 are pressed with a certain force or more for a certain period of time or more can be determined based on the detection signal from the grip sensor 24 as described above. Instead of the negative acceleration, the acceleration in the rearward direction of the vehicle body may be used to determine the collision with the step of the step 12.

When the step is relatively low, the front wheel 12 is lifted by the driving force of the rear wheel 13 described above, and the front wheel 12 can ride on the step. If the front wheel 12 is not lifted here, the user subsequently weakens the force for pushing the handle 14. At this time, the moment in the direction of pushing down the front wheel 12 on the electrically assisted walking vehicle 10 (the moment against the lifting of the front wheel 12) is reduced. The control unit 16 maintains the driving force of the rear wheels 13 in the forward direction to a certain level or more to drive the rear wheels 13 forward (see FIG. 7). As a result, the moment in the direction of lifting the front wheel 12 increases, and the front wheel 12 acts to be lifted.

If the front wheel 12 still does not lift, the user subsequently pulls the handle 14 backward. At this time, the force pulling the steering wheel 14 rearward generates a moment in the direction of lifting the front wheel 12 around the rear wheel 13, and acts to lift the front wheel 12 together with the driving force of the rear wheel 13. In this way, in addition to the operating force from the motor 20, the user operates the operating handle 14 to generate a moment in the direction of lifting the front wheels 12 in the electrically assisted wheelie 10 (see arrow M in FIG. 2). The front wheel 12 can be lifted more reliably (the electrically assisted walking vehicle 10 is wheelie). Instead of the operation of pulling the steering wheel 14 rearward, the user may lift the front wheel 12 by stepping on a pedal (not shown) fixed to the rear of the rotation axis of the rear wheel 13.

At this time, as the front wheel 12 is lifted with respect to the rear wheel 13, a gap is generated between the front wheel 12 and the step. Since the rear wheels 13 are driven in the forward direction, the electrically assisted walking vehicle 10 moves forward so as to fill this gap, and the front wheels 12 can be brought into contact with the upper stage of the step. As a result, the front wheel 12 can smoothly ride on the step.

After the front wheels 12 are lifted, the control unit 16 gradually reduces the driving force in the forward direction of the rear wheels 13 by the first reduction amount. In this case, since the rear wheels 13 do not accelerate too much after the front wheels 12 have overcome the step, the front wheels 12 can smoothly overcome the step. The timing for starting the reduction of the driving force is a predetermined condition when the control unit 16 controls the drive unit in order to lift the front wheel 12 (when the user intends to move the electrically assisted walking vehicle 10 forward). It can be set when the condition (condition for determining that the front wheel 12 has collided with the step) is no longer satisfied. For example, when the handle 14 is no longer pushed by a certain force or more (when the user weakens the force to push the handle 14 or when the handle 14 is pulled backward), or when the rear wheel 13 has a constant speed in the forward direction. It may be when it is rotated by the above.

After that, the user pushes the pair of handles 14 with the front wheels 12 lifted with respect to the rear wheels 13. As a result, the electrically assisted walking vehicle 10 can be advanced, and the front wheels 12 can overcome the step.

In this way, when the user pulls the handle 14 backward, a moment around the rear wheel 13 can be generated, so that the front wheel 12 can be easily lifted together with the driving force of the motor 20. it can. Therefore, the user can easily get over the step by the front wheel 12 without lifting the electrically assisted walking vehicle 10. As described above, the front wheel 12 may be lifted only by increasing the driving force of the motor 20 (driving unit) without the user pulling the handle 14 backward, such as when the step is low.

If the output of the motor 20 continues to increase even after the front wheels 12 have overcome the step, the electrically assisted walking vehicle 10 may accelerate too much. Therefore, if any of the following conditions (1) to (3) is satisfied after the front wheel 12 is lifted with respect to the rear wheel 13, the control unit 16 determines that the front wheel 12 has overcome the step. As described above, the electrically assisted walking vehicle 10 may not be accelerated. In this case, the control unit 16 controls the motor 20 to increase the amount of reduction in the driving force of the rear wheels 13 by the motor 20. Specifically, the amount of decrease in the driving force of the rear wheels 13 in the forward direction is set to a second amount of decrease larger than the above-mentioned first amount of decrease (see the two-dot chain line in FIG. 7). Alternatively, the control unit 16 may set the driving force of the rear wheels 13 in the forward direction to zero.

(1) When the inclination angle of the electrically assisted walking vehicle 10 detected by the inclination detection sensor 23 exceeds a certain value (because the electrically assisted walking vehicle 10 tilts when the front wheel 12 climbs a step).

(2) When the rotational speed of the rear wheel 13 detected by the speed sensor 22b satisfies a predetermined condition. For example, when the rotation speed of the rear wheels 13 exceeds a certain value (because the speed of the rear wheels 13 increases at the moment when the front wheels 12 cross the step. Also, when the rear wheels 13 idle, the rear wheels 13 Because the rotation speed of is increased).

(3) When the distance between the user and the electrically assisted walking vehicle 10 detected by the leg detection sensor 25 exceeds a certain value (the speed of the rear wheels 13 increases at the moment when the front wheels 12 cross the step). However, because the electrically assisted walking vehicle 10 is separated from the user).

When it is determined that the user intends to move the electric vehicle forward (intentionally to move forward), the method is not limited to the above method, and for example, (i) the amount of rotation of the front wheels 12 or the rear wheels 13 ( ii) Output from a strain gauge provided on the electrically assisted pedestrian vehicle 10, (iii) tire pressure of the front wheels 12 or rear wheels 13, (iv) acceleration in the front-rear direction of the electrically assisted pedestrian vehicle 10, (v) steering wheel 14 One or more of the elements selected from the output from the pressure sensor provided in (vi), the output from the myoelectric sensor provided in the handle 14, etc., and (vi) the movement of the user's foot. You may consider it.

(Step detection)
Next, the details of the process for detecting the collision of the electrically assisted walking vehicle (electric vehicle) with the step will be described.

An example of step detection by a conventional electrically assisted walking vehicle (electric vehicle) is step detection based on acceleration. However, the electrically assisted walking vehicle detects the acceleration not only when it collides with a step. For example, the acceleration is detected when the user stops the electrically assisted walking vehicle, and the acceleration is also detected when the electrically assisted walking vehicle collides with an object other than the step. In order to improve the detection accuracy of the step, the difference between the acceleration detected when the electrically assisted walking vehicle collides with the step and the acceleration detected when the user stops the electrically assisted walking vehicle is determined. It is necessary to determine. Similarly, the difference in acceleration detected depending on the type of object with which the electrically power assisted walking vehicle collides must be taken into consideration.

FIG. 8 is a graph showing an example of acceleration and threshold value detected in each case of collision with a step and stop operation. The horizontal axis of the graph of FIG. 8 indicates the speed of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle). The vertical axis of the graph in FIG. 8 shows negative acceleration. The negative acceleration means the acceleration (deceleration) in the direction of decelerating the electrically assisted walking vehicle 10 (electric vehicle).

FIG. 8 is a blot of the relationship between the velocity measured at the time of a collision with a step and the stop operation by the user and the negative acceleration. Referring to FIG. 8, since an impact is applied to the electrically power assisted walking vehicle 10 at the time of a collision with a step, a larger acceleration is detected as compared with the stopping operation by the user. That is, the measuring unit may measure at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body. In this case, the determination unit 16a determines the front wheel when at least one of the acceleration in the direction of decelerating the vehicle body measured by the measurement unit and the acceleration in the rearward direction of the vehicle body is larger than the threshold value (seventh threshold value). It may be estimated that 12 has come into contact with the step. Further, the determination unit 16a states that the front wheels 12 have come into contact with the step when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or less than the threshold value. It does not have to be estimated. Thereby, the contact with the step of the front wheel 12 can be determined.

For example, if an acceleration smaller than the threshold value is detected during a certain period of time before the step overcoming control is performed (that is, when it is determined that the front wheel 12 touches the step), the set value of the threshold value is large. It is possible that the front wheel 12 was not actually in contact with the step because it was too much, but it was not determined that the front wheel 12 was in contact with the step. Therefore, the determination unit 16a is set from the threshold value (seventh threshold value) in a predetermined period before the control unit 16 controls the front wheel 12 to overcome the step and then the control unit 16 controls the front wheel 12 to overcome the step. If a small acceleration is detected, the threshold value (seventh threshold value) may be changed to a smaller value. Further, the acceleration detected before the step overcoming control is performed (that is, when it is determined that the front wheel 12 touches the step) is larger than the threshold value, and the difference between the detected acceleration and the threshold value is predetermined. If it is greater than the value of, the threshold setting may be too small. Therefore, in the determination unit 16a, the acceleration measured by the measurement unit when the control unit 16 overcomes the step of the front wheel 12 is larger than the threshold value (seventh threshold value) and the threshold value (seventh threshold value). ), The threshold value (seventh threshold value) may be changed to a larger value. In this way, the accuracy of step contact detection can be improved by adjusting the threshold value used for determining the contact between the front wheel 12 and the step when the front wheel 12 has successfully overcome the step.

As described above, the electrically assisted walking vehicle 10 may include a storage unit 16b that stores the measured values of the measurement unit. In this case, the determination unit 16a may adjust the threshold value (seventh threshold value) based on the measured value stored in the storage unit 16b. By using the measured values stored in the storage unit 16b at the time of step overcoming control in the past multiple times, it is possible to adjust the threshold value with higher accuracy. Further, not limited to the seventh threshold value, other threshold values described in the present specification may be adjusted based on the measured values stored in the storage unit 16b.

With reference to FIG. 8, it can be seen that a large acceleration tends to be detected as the speed of the electrically power assisted walking vehicle 10 increases, both when colliding with a step and when the user stops the vehicle. When the speed measured in each case and the acceleration in the rearward direction of the vehicle body are plotted on a graph, the same relationship as in FIG. 8 is established.

Rather than always using the same threshold value to detect a collision with a step, the threshold value used can be increased according to the speed of the electrically power assisted walking vehicle 10. Then, when the measured acceleration is larger than the threshold value, the electrically assisted walking vehicle 10 can execute the step overcoming operation. The control unit 16 sets the threshold value of the absolute value of acceleration, which is a condition for executing the step overcoming operation as the speed of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measuring unit increases. (6th threshold value) may be set large. The broken line in FIG. 8 shows an example of such a threshold value (fourth threshold value). This makes it possible to improve the detection accuracy of the step.

An example of the threshold value function is T = Σ (α _n v ^ β _n ) + γ, but the format may be different from these. Here, v is the velocity of the vehicle body, and α _n and β _n are coefficients (positive real numbers) larger than 0. γ is an arbitrary coefficient. γ may be a positive real number, 0 or a negative real number. When the structure and the materials used differ depending on the side surface of the electrically power assisted walking vehicle 10, a different threshold value or a function of the threshold value may be used depending on the direction. For example, when at least one of the materials, structures, and sizes of the front wheels and the rear wheels is different, different coefficients may be used in the detection of the collision with the step of the front wheel and the collision with the step of the rear wheel.

FIG. 9 is a graph showing an example of the acceleration detected when the electrically assisted walking vehicle 10 collides with a soft object and the acceleration detected when the electrically assisted walking vehicle 10 collides with a step. Here, the soft object means an object having a repulsive hardness smaller than that of a step. An example of such an object is the human body. The horizontal axis of the graph of FIG. 9 shows the speed of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle). The vertical axis of the graph in FIG. 9 shows negative acceleration (deceleration).

FIG. 9 is a blot of the relationship between the speed measured when the electrically power assisted walking vehicle 10 collides with a soft object and when the electrically power assisted walking vehicle 10 collides with a step and the negative acceleration. Referring to FIG. 9, when the speed of the electrically assisted walking vehicle 10 is about the same, the time when the electrically assisted walking vehicle 10 collides with a step is higher than the time when the electrically assisted walking vehicle 10 collides with a soft object. It can be seen that a large acceleration is detected. From this result, it can be seen that the magnitude of the repulsive hardness of the object collided with by the electrically assisted walking vehicle 10 can be estimated from the magnitude of the acceleration detected at the time of collision. For example, by comparing the detected acceleration with the threshold value, it is possible to distinguish between a collision with a step and a collision with the human body. In the graph of FIG. 9, negative acceleration (acceleration in the direction of decelerating the vehicle body) is shown, but even if the graph is created using the acceleration in the rear direction of the vehicle body instead of the negative acceleration, A similar relationship holds.

Also in the example of FIG. 9, the detected acceleration tends to increase as the speed of the electrically assisted walking vehicle 10 increases.

The determination unit 16a of the electrically power assisted walking vehicle 10 can determine whether or not to perform the step overcoming operation by comparing the measured acceleration with the threshold value. For example, in the determination unit 16a, when at least one of the acceleration in the direction of decelerating the vehicle body measured by the measurement unit and the acceleration in the rearward direction of the vehicle body is equal to or less than a predetermined threshold value, the front wheels 12 are other than the step. It may be presumed that it has come into contact with an object. In the determination unit 16a, at least one of the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit and the acceleration in the rearward direction of the vehicle body is a threshold value (fourth). When it is less than or equal to the threshold value), it is not necessary to cause the drive unit to perform the step overcoming operation. As a result, when there is a possibility that the electrically assisted walking vehicle 10 is stopped by the user or the electrically assisted walking vehicle 10 comes into contact with a person, it becomes difficult to perform the step climbing operation, and the safety of the electrically assisted walking vehicle 10 is improved. Can be enhanced.

In the determination unit 16a, the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit or the acceleration in the rearward direction of the vehicle body is larger than the threshold value (fourth threshold value). Occasionally, the drive unit may be made to perform an operation of overcoming a step. Generally, when the acceleration (deceleration) in the direction of decelerating the electric vehicle or the acceleration in the rear direction of the vehicle body is larger than the threshold value, it can be estimated that the electric vehicle has come into contact with the step. For example, the measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body, and the determination unit 16a measures the acceleration in the direction of decelerating the vehicle body measured by the measuring unit or It may be estimated that the front wheels 12 come into contact with the step when at least one of the accelerations in the rearward direction of the vehicle body is larger than a predetermined threshold value (fifth threshold value). As a result, the determination unit 16a can cause the drive unit to execute the operation of overcoming the step only when it is determined that the collision occurs with the step.

Further, the control method of the electrically assisted walking vehicle (electric vehicle) is whether or not to perform step overcoming control based on at least one of the speed and the acceleration applied to the vehicle body and the step of measuring at least one of the speed and the acceleration. It may include a step of determining whether or not. Further, the control method of the electrically assisted walking vehicle (electric vehicle) further includes a step of determining whether or not the front wheel 12 has touched the step based on at least one of speed and acceleration, and a step that the front wheel 12 has touched the step. It may include a step of overcoming a step when it is estimated. The step overcoming control may include at least one of a control for increasing the driving force for driving the wheels, a control for turning the vehicle body, and a control for increasing the driving force while turning the vehicle body.

Further, in the control program of the electrically assisted walking vehicle (electric vehicle), whether the front wheels 12 come into contact with the step based on the step of measuring at least one of the speed and the acceleration applied to the vehicle body and at least one of the speed and the acceleration. It may include a step of determining whether or not, and a step of controlling overcoming of the step when it is presumed that the front wheel 12 has come into contact with the step. The step overcoming control may include at least one of a control for increasing the driving force for driving the wheels, a control for turning the vehicle body, and a control for increasing the driving force while turning the vehicle body. The control program may be executed by the control unit 16 or the determination unit 16a, or may be executed by an external controller, server, or the like.

In order to obtain the negative acceleration (deceleration), which is the acceleration in the direction of decelerating the electrically assisted walking vehicle 10 (electric vehicle), it is necessary to specify the traveling direction of the electrically assisted walking vehicle 10. The traveling direction of the electrically assisted walking vehicle 10 can be estimated based on, for example, the measured value of the speed sensor 22b.

The acceleration used to determine whether or not the electrically power assisted walking vehicle 10 overcomes a step is not limited to negative acceleration (deceleration). For example, the determination unit 16a determines whether or not the control unit 16 is to execute the step overcoming control based on the acceleration applied in the rearward direction of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit. You may. When making a determination based on the acceleration of the electrically assisted walking vehicle 10 in the rearward direction, it is not necessary to specify the traveling direction of the vehicle body.

For example, at least one of the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the determination unit 16a and the measurement unit or the acceleration in the rearward direction of the vehicle body is equal to or less than the fifth threshold value. At some point, it is not necessary for the control unit 16 to perform step overcoming control. Then, the determination unit 16a has at least one of the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit and the acceleration in the rearward direction of the vehicle body from the fifth threshold value. When it is large, the control unit 16 may be made to perform step overcoming control.

Further, the determination unit 16a of the electrically assisted walking vehicle 10 (electric vehicle) may determine whether or not the control unit 16 is to be controlled to overcome the step based on the vibration detected by the measurement unit.

The determination unit 16a has a step on the control unit 16 when the representative value of the frequency spectrum of the vibration of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit is equal to or less than the sixth threshold value. It is not necessary to perform overcoming control. Further, the determination unit 16a has a step on the control unit 16 when the representative value of the frequency spectrum of the vibration of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit is larger than the sixth threshold value. Overcoming control may be performed. That is, the measuring unit measures the frequency spectrum of the vibration of the vehicle body, and the judgment unit 16a determines when the representative value of the measured (frequency spectrum) value of the measuring unit is larger than the threshold value (eighth threshold value). It may be estimated that the front wheel 12 has come into contact with the step. Further, when the representative value of the value (of the frequency spectrum) measured by the measurement unit is equal to or less than the threshold value (eighth threshold value), the determination unit 16a does not have to estimate that the front wheel 12 has touched the step. Good. A specific example of the representative value will be described later.

It is generally known that the vibration generated when objects collide with each other depends on the repulsive hardness of the objects. When the repulsive hardness of an object is large, the frequency of vibration generated at the time of collision becomes large. Therefore, when the frequency of the detected vibration is larger than the threshold value, it can be estimated that the electrically assisted walking vehicle 10 (electric vehicle) has collided with the step. When the frequency of the detected vibration is equal to or lower than the threshold value, it is estimated that the electrically assisted walking vehicle 10 collides with an object other than the step or the user has stopped the electrically assisted walking vehicle 10. be able to. An example of a collision (or contact) with an object other than a step is a case where any part of the electrically power assisted walking vehicle 10 (electric vehicle) hits another person's foot or luggage. However, the type of the object is not particularly limited.

The representative value of the frequency spectrum may be the frequency of the maximum peak in the frequency spectrum, or may be the load average value of a plurality of peaks in the frequency spectrum. Further, it may be an intermediate frequency in the frequency spectrum or an average frequency. That is, the calculation method of the representative value is not particularly limited.

When the front side of the electrically power assisted walking vehicle 10 collides with an object such as a step, a force is applied in the front-rear direction of the vehicle body. Therefore, the vibration of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measuring unit may include the vibration of the vehicle body in the front-rear direction. The direction of vibration of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measuring unit of the electrically assisted walking vehicle 10 is not particularly limited.

The electrically assisted walking vehicle 10 (electric vehicle) may include a cushioning member that covers at least a part of the front surface of the vehicle body or both side surfaces in the width direction of the vehicle body. If the frame of the electrically assisted walking vehicle 10 (electric vehicle) collides with a part of the human body that is close to the bone and is relatively hard, such as a shin, a large deceleration may occur and the determination unit 16a may erroneously detect a step. Therefore, by providing the first buffer member on at least a part of the front or both side surfaces in the width direction of the electrically assisted walking vehicle 10 (electric vehicle), it is possible to prevent a large deceleration from being detected at the time of a collision with a human body. it can.

FIG. 10 is a schematic view showing a configuration example in which a cushioning material is provided in front of the vehicle body. The pipe frame 31 of the electrically assisted walking vehicle 10 of FIG. 10 projects to the front of the vehicle body. A cushioning member 81 is provided at the tip of a portion of the pipe frame 31 that protrudes forward. Examples of the cushioning member 81 include rubber, urethane foam, foamed resin, various springs, and the like, but the type of cushioning member is not particularly limited. Here, FIG. 10 shows the configuration of the pipe frame 31 and the cushioning member 81 on the left side of the electrically power assisted walking vehicle 10. Similar to the left side, the pipe frame 31 on the right side of the electrically assisted walking vehicle 10 may be provided with a cushioning member 81 at the tip of a portion protruding forward. The configuration provided in FIG. 10 is only an example. Therefore, the cushioning member may be integrally formed, or may be mounted on the electrically assisted walking vehicle by a method different from that shown in FIG. Further, the cushioning member may be provided on at least a part of both side surfaces in the width direction of the electrically assisted walking vehicle.

The step detection and step overcoming functions of the conventional walking assist device were based on the premise that the walking assist device entered the step from almost the front (almost in the vertical direction). Therefore, when the walking assist device enters the step at an angle and the right front wheel and the left front wheel come into contact with the step with a time difference, it is difficult to get over the step. In the following, step detection when the walking assist device enters at an angle with respect to the step will be described.

FIG. 11 is a plan view of the electrically assisted walking vehicle 10 (electric vehicle) when viewed from above. In the plan view of FIG. 11, the electrically assisted walking vehicle 10 is moving in the direction of the broken line P of the step 80 (in the upper left direction of FIG. 11). That is, the broken line P indicates the traveling direction of the electrically power assisted walking vehicle 10. With reference to FIG. 11, since there is a step 80 at the end of the broken line P, it can be seen that the electrically assisted walking vehicle 10 is approaching in the direction of the step 80. When the electrically assisted walking vehicle 10 is turning, the traveling direction of the electrically assisted walking vehicle 10 changes depending on the time. Therefore, it can be said that the broken line P indicates the direction of the speed vector of the electrically power assisted walking vehicle 10 at a certain time.

The broken line S in FIG. 11 is a vertical line of the step 80 and indicates the front (vertical) direction of the step 80. On the other hand, the broken line P indicating the traveling direction of the electrically power assisted walking vehicle 10 forms an angle θ with respect to the perpendicular line S of the step 80. In this way, the electrically assisted walking vehicle 10 may enter at an angle with respect to the vertical direction instead of entering from the vertical direction of the step. The step 80 does not necessarily have to be linear as in the example of FIG. For example, when the step is curved, the perpendicular line of the tangent line of the step can be a perpendicular line.

As shown in FIG. 11, when the electrically assisted walking vehicle 10 approaches the step 80 at an angle, either the front right wheel or the left front wheel collides with the step 80 first. In the example of FIG. 11, it can be seen that the right front wheel of the electrically assisted walking vehicle 10 collides with the step 80. The arrow a is a vector indicating the acceleration applied to the vehicle body due to the collision with the step 80 of the right front wheel. The arrow l of the electrically power assisted walking vehicle 10 indicates the front-rear direction of the vehicle body, and the arrow w indicates the width direction of the vehicle body. With reference to FIG. 11, it can be seen that the acceleration vector a has a component in the front-rear direction l of the vehicle body and a component in the width direction w of the vehicle body.

Next, an example of the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body detected by the electrically assisted walking vehicle 10 will be described.

FIG. 12 is a graph showing the difference in acceleration detected by the front wheels that collided. The horizontal axis of FIG. 12 shows the acceleration in the front-rear direction of the vehicle body. On the other hand, the vertical axis of FIG. 12 shows the acceleration in the width direction of the vehicle body. In the example of FIG. 12, regarding the acceleration in the front-rear direction of the vehicle body, the acceleration in the front direction of the vehicle body is a positive value, and the acceleration in the front direction of the vehicle body is a negative value. Regarding the acceleration in the width direction of the vehicle body, the acceleration in the right direction is a positive value and the acceleration in the left direction is a negative value. The correspondence between the direction of acceleration and the positive and negative values shown here is an example, and a different correspondence may be used.

The graph of FIG. 12 shows that when any of the front wheels collides with a step, not only the acceleration in the front-rear direction of the vehicle body but also the acceleration in the width direction of the vehicle body is generated. When the front right wheel collides with a step, acceleration in the left direction is detected. On the other hand, when the left front wheel collides with a step, acceleration in the right direction is detected. Looking at the acceleration measured when both front wheels collide with the step in the graph of FIG. 12, the acceleration in the rear direction of the vehicle body tends to be larger than when one of the front wheels collides with the step. I understand. In addition, when both front wheels collide with a step, acceleration in the width direction is also detected. In the graph of FIG. 12, the acceleration in the width direction detected when both front wheels collide with the step is biased to the rightward acceleration because the left front wheel precedes the right front wheel when the measurement is performed. It is presumed that this is because it often collides with a step.

Looking at the results in FIG. 12, it can be seen that it is possible to estimate which of the right front wheel and the left front wheel collided with the step based on the detected direction of acceleration in the width direction. That is, the acceleration measured by the measuring unit is either at least the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) or the acceleration in the front-rear direction of the vehicle body, and the electric assisted walking vehicle 10 (electric vehicle). It may include the acceleration in the width direction of the vehicle body. Then, the determination unit 16a can estimate which of the left and right wheels has come into contact with the step based on the acceleration in the width direction of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle). That is, the determination unit 16a may estimate which front wheel is presumed to have come into contact with the step based on the measurement value of the measurement unit.

Further, in the determination unit 16a, based on the measured value of the measurement unit, which of the left front wheel and the right front wheel touched the step (one-sided contact), or the left front wheel and the right front wheel touched the step (both wheels contacted). ) Can be determined. This makes it possible to control the vehicle body including the step overcoming operation according to the mode of contact with the step (one-sided contact or two-wheel contact). For example, the determination unit 16a can discriminate between one-sided contact and two-wheel contact based on the acceleration in the vehicle body width direction and the acceleration in the vehicle body front-rear direction. For example, the determination unit 16a can determine that the contact is one-sided when the acceleration in the vehicle body width direction is _{larger than the threshold value th w.} Further, the determination unit 16a can determine that the two wheels are in contact when the acceleration in the vehicle body front-rear direction is _{larger than the threshold value th fb.} Further, when the acceleration in the vehicle body width direction _{is smaller than the threshold value th w and} the acceleration in the vehicle body front-rear direction is _{larger than the threshold value th fb} , it may be determined that the two wheels are in contact.

The measuring unit may measure at least one of the acceleration in the direction of decelerating the vehicle body, the acceleration in the rearward direction of the vehicle body, and the acceleration in the width direction of the vehicle body. When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit becomes equal to or higher than a predetermined threshold value (first threshold value). Estimate whether the left front wheel or the right front wheel touches the step. Further, in the determination unit 16a, at least one of the acceleration in the direction of decelerating the vehicle body measured by the measurement unit and the acceleration in the rearward direction of the vehicle body is equal to or higher than a predetermined threshold value (first threshold value). After that, when the maximum value of the absolute value of the acceleration in the width direction of the vehicle body measured within a predetermined period becomes equal to or higher than the predetermined threshold value (second threshold value), either the left front wheel or the right front wheel becomes a step. It may be estimated whether they have come into contact with each other. Thereby, the contact with the step of the left front wheel or the right front wheel can be distinguished and determined.

The acceleration in the width direction of the vehicle body used for the determination is at the same time as when the acceleration in the direction of decelerating the vehicle body or the acceleration in the rear direction of the vehicle body becomes equal to or higher than the threshold value (first threshold value). It may be measured or may be measured at different times. The control unit 16 can execute an operation of overcoming a step according to the result of the determination.

The control method of the electrically assisted walking vehicle 10 (electric vehicle) measures at least the first acceleration, which is either the acceleration in the direction of decelerating the vehicle body or the acceleration in the front-rear direction of the vehicle body, and the second acceleration in the width direction of the vehicle body. Steps to be performed, a step to estimate which of the left and right wheels has touched the step based on the measured first acceleration and the second acceleration, and a step corresponding to the wheel estimated to be in contact with the step. It may include a step of performing an overcoming motion.

Further, the control program of the electrically assisted walking vehicle 10 (electric vehicle) includes a first acceleration which is at least either an acceleration in the direction of decelerating the vehicle body or an acceleration in the front-rear direction of the vehicle body, and a second acceleration in the width direction of the vehicle body. The step of estimating which of the left and right wheels touched the step based on the measured first acceleration and the second acceleration, and the step of estimating which wheel was in contact with the step, according to the wheel estimated to be in contact with the step. It may include a step of executing a step overcoming operation.

Although the method of measuring the acceleration in a plurality of directions by the acceleration sensor 22a and estimating the wheel in contact with the step has been described here, it does not prevent the use of the speed value measured by the speed sensor 22b. For example, when the amount of decrease in speed within a predetermined period is equal to or greater than the threshold value, it can be estimated that there is contact with the step. Further, the speed sensor 22b may be used to measure the speed in a plurality of directions, or both the speed measurement and the acceleration measurement may be performed. That is, the determination unit 16a may estimate the front wheels in contact with the step based on at least one of speed and acceleration. The front wheels that come into contact with the step may be only the left front wheel, only the right front wheel, or both the left front wheel and the right front wheel.

The graph of FIG. 13 shows the acceleration measured when the electrically assisted walking vehicle 10 collides with a step while turning and the acceleration measured when the electrically assisted walking vehicle 10 collides with a step while traveling straight. There is. The vertical axis of the graph of FIG. 13 shows the acceleration in the width direction of the vehicle body. On the other hand, the horizontal axis of the graph of FIG. 13 indicates the acceleration in the front-rear direction of the vehicle body.

With reference to the graph of FIG. 13, referring only to the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body, it may be that the electrically assisted walking vehicle 10 collides with a step while traveling straight, or the electrically assisted walking vehicle 10 turns. However, it is not always clear whether it collided with a step.

Therefore, it is possible to distinguish between the former case and the latter case by also using the information on the rotation of the wheels. For example, when the speed sensor 22b measures the rotation speed of the rear wheels, the deceleration (negative acceleration) of the rear wheels can be obtained by adding a negative sign to the value obtained by differentiating the rotation speed with respect to time. .. If the right front wheel collides with a step, the deceleration of the right rear wheel tends to be larger than the deceleration of the left rear wheel. Therefore, did the electrically power assisted walking vehicle 10 collide with the step while traveling straight by using not only the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body but also the deceleration of the right rear wheel and the deceleration of the left rear wheel? Alternatively, it can be estimated whether the electrically assisted walking vehicle 10 collided with the step while turning.

For example, when the rear wheel 13 includes a left rear wheel and a right rear wheel that are arranged apart from each other in the width direction of the vehicle body, the measuring unit may at least accelerate the left rear wheel in the rotational direction and the right rear wheel. The average value with the acceleration in the rotation direction or the difference between the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel may be calculated. Further, when the front wheels 12 include the left rear wheel and the right rear wheel that are arranged apart from each other in the width direction of the vehicle body, the measuring unit is at least in the acceleration in the rotation direction of the left front wheel and the rotation direction of the right front wheel. The average value with the acceleration or the difference between the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel may be calculated. Thereby, it is possible to distinguish which of the right front wheel and the left front wheel touches the step.

As the first acceleration, the measuring unit determines the average value of the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel. The average value may be calculated. Further, as the second acceleration, the measuring unit determines the difference between the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel. The difference may be calculated. In this case, if the second acceleration is larger than the threshold value, it may be estimated that the electrically assisted walking vehicle 10 (electric vehicle) is turning. Also by this method, it is possible to distinguish which of the right front wheel and the left front wheel touches the step.

Here, different threshold values may be used depending on the value of the first acceleration. For example, a larger threshold can be used as the first acceleration increases. Examples of the threshold function include T = Σ (α _n a ^ β _n ) + γ, but thresholds with different definitions may be used. Here, a is the acceleration speed of the vehicle body (first acceleration), and α _n and β _n are coefficients (positive real numbers) larger than 0. γ is an arbitrary coefficient. γ may be a positive real number, 0 or a negative real number.

The graph of FIG. 14 shows an example of the time waveform of the acceleration measured at the time of collision with the step of the electrically power assisted walking vehicle 10. The horizontal axis of FIG. 14 is time, and the vertical axis shows the detected acceleration. The graph of FIG. 14 shows measured values of acceleration in a plurality of operation patterns of the electrically power assisted walking vehicle 10. FIG. 14 shows a waveform 90 measured when the electrically assisted walking vehicle 10 collides with the step from the front, and a waveform measured when each front wheel of the electrically assisted walking vehicle 10 collides with the step before and after the time. 91 and the waveform 92 measured when the user performs the stop operation of the electrically power assisted walking vehicle 10 are shown.

In the waveform 90, the electrically assisted walking vehicle 10 collides with a step at a time of 0.0 seconds, a large impact is applied as compared with other waveforms, and a large acceleration is detected. On the other hand, in the waveform 91, since each front wheel collides with the step before and after the time, the impact is dispersed a plurality of times, and the magnitude of the detected acceleration peak is smaller than that of the waveform 90. ing. In the waveform 92, the electrically assisted walking vehicle 10 does not collide with the step, and the user manually stops the electrically assisted walking vehicle 10. Therefore, the magnitude of the acceleration peak detected in the waveform 92 is even smaller than that of the waveform 91.

It is necessary to determine the threshold value to be used when detecting the collision with the step in consideration of the acceleration detected in each operation pattern illustrated in FIG. For example, if the threshold value is set based on the peak value of the acceleration (for example, waveform 90) detected when the electrically assisted walking vehicle 10 collides from the front of the step, the threshold value is too large, so that the electrically assisted walking vehicle 10 walks. When each front wheel of the vehicle 10 collides with a step before and after the time (for example, waveform 91), the step may not be detected. On the other hand, if the threshold value is set too small, the step may be erroneously detected when the user manually stops the electrically assisted walking vehicle 10.

Therefore, in order to improve the detection accuracy of the step by the electrically assisted walking vehicle 10, the threshold value can be used properly according to the conditions. For example, it is estimated whether or not the electrically assisted walking vehicle 10 is turning by the above method, and when it is estimated that the electrically assisted walking vehicle 10 is turning, the electrically assisted walking vehicle 10 is traveling straight. You may use a different threshold or threshold function. That is, in the determination unit 16a, the maximum value of the absolute value of the acceleration in the width direction of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit is equal to or higher than a predetermined threshold value (second threshold value). The threshold value of acceleration (fifth threshold value), which is a condition for executing the step overcoming operation when the step is reached, may be set small. Here, as an example of the acceleration, the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measuring unit or the acceleration in the rearward direction of the vehicle body can be mentioned. However, it may be determined whether or not the step overcoming operation can be executed based on other accelerations. Further, the threshold value may be selected from any of a plurality of fixed values, or may be a function having the speed of the vehicle body as a parameter.

With reference to the waveform 91 of FIG. 14, which shows the acceleration measured when each front wheel of the electrically power assisted walking vehicle 10 collides with a step before and after the time, the acceleration at time 0.0 second and time 0.6 second is shown. There is a peak of. The acceleration at the first peak (0.0 seconds) is greater than the peak detected later (0.6 seconds). At each peak, it is estimated that the front wheels on different sides are in contact with the step. Since the kinetic energy of the electrically assisted walking vehicle 10 is reduced by the contact with the first step, it is considered that the acceleration detected at the second contact with the step is small. Therefore, when each front wheel of the electrically power assisted walking vehicle 10 collides with a step before and after the time, a different threshold value can be used depending on the number of collisions.

For example, when the electrically power assisted walking vehicle 10 approaches the step at an angle and the right front wheel and the left front wheel come into contact with the step at different times, if one of the front wheels detects the step and the contact, the step of the other front wheel As the threshold value used to detect contact with, a threshold value smaller than the threshold value used to detect contact with the first step is used. That is, the measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body, and the determination unit 16a measures the electrically assisted walking vehicle 10 (electric vehicle) measured by the measuring unit. ) When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body exceeds a threshold value smaller than the first threshold value (third threshold value), the left front wheel and the right It may be estimated that the front wheels have come into contact with the step.

As a result, by using an excessively small threshold value, it is possible to prevent erroneous detection of a step in a scene other than a collision with a step, such as when the electrically assisted walking vehicle 10 is manually stopped.

When the electrically power assisted walking vehicle 10 collides with a step, the peak of the acceleration in the width direction of the vehicle body may be measured later than the peak of the acceleration in the front-rear direction of the vehicle body. Therefore, in the determination unit 16a, the acceleration in the direction of decelerating the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured by the measurement unit or the acceleration in the rearward direction of the vehicle body is equal to or higher than the first threshold value. After that, when the maximum value of the absolute value of the acceleration in the width direction of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle) measured within a predetermined period becomes the second threshold value or more, either the left or right wheel is turned on. It may be estimated whether or not it touched the step. An example of the predetermined period described above is 10 milliseconds, but a different value may be used.

(Overcoming steps)
Next, the operation of overcoming a step by the electrically assisted walking vehicle (electric vehicle) will be described.

FIG. 15 is a plan view showing a first example of an electrically assisted walking vehicle approaching at an angle with respect to a step. In the following, with reference to FIG. 15, the operation of overcoming the step 80 when the electrically assisted walking vehicle 10 enters the step 80 at an angle will be described. When the vector (broken line P) related to the traveling direction of the electrically assisted walking vehicle 10 forms an angle of 0 degrees or more with the perpendicular line (broken line S) of the step 80, the electrically assisted walking vehicle 10 with respect to the step 80. It is assumed that the vehicle is approaching at an angle. In FIG. 15, the right front wheel of the electrically power assisted walking vehicle 10 is in contact with the step 80. It is assumed that the determination unit 16a has detected a collision with the step on the right front wheel based on the measurement value of the measurement unit.

15, white arrows and driving force d _pl of the left rear wheel, respectively, show the driving force d _pr of the right rear wheel. In the example of FIG. 15, a driving force d _pl of the left rear wheel, assuming that the driving force d _pr of the right rear wheel is set equal among the resultant force of the driving force d _pl and driving force d _pr, step 80 The force in the direction perpendicular to is multiplied by sin (90-θ). Therefore, as the angle θ becomes larger, it becomes more difficult for the electrically power assisted walking vehicle 10 to get over the step 80. Therefore, the vehicle body of the electrically assisted walking vehicle 10 is turned so that a larger force is applied in the direction perpendicular to the step 80 when the step 80 is overcome.

For example, the control unit 16 as in the example of FIG. 15, controls the driving unit, can be made larger than the driving force d _pr of the right rear wheel driving force d _pl of the left rear wheel. As a result, a force for turning the vehicle body of the electrically assisted walking vehicle 10 to the right acts, and the step 80 can be overcome at a smaller angle θ. As described above, the control unit 16 is based on the driving force of at least one of the front wheels 12 on the side estimated to have come into contact with the step or the rear wheels 13 located on the same side in the width direction of the vehicle body of the front wheels 12. A large driving force may be generated in at least one of the front wheels 12 and the rear wheels 13 located on the opposite side of the front wheels 12 in the width direction of the vehicle body, which is presumed to have come into contact with the step.

Further, the control unit 16 generates a driving force only in at least one of the front wheels 12 and the rear wheels 13 located on the opposite side of the vehicle body of the front wheels 12 presumed to have come into contact with the step in the width direction. May be good. That is, the driving force of at least one of the front wheels 12 and the rear wheels 13 located on the opposite side of the vehicle body of the front wheels 12 presumed to have come into contact with the step has been presumed to have come into contact with the step. It may be larger than the driving force of at least one of the driving portions of the rear wheels 13 located on the same side in the width direction of the vehicle body of the front wheels 12 and the front wheels 12. As a result, after either the left front wheel or the right front wheel comes into contact with the step, the electrically assisted walking vehicle 10 can be made to face the step. The wheel on the side in contact with the step can be estimated by using the method described in the above description of the step detection process.

When the electrically assisted walking vehicle 10 is approaching the step 80 at an angle, it is not always necessary to generate a driving force for turning the vehicle body of the electrically assisted walking vehicle 10. For example, the control unit 16 may generate a driving force only in the driving unit of the rear wheels 13 located on the same side in the width direction of the vehicle body of the front wheels 12 presumed to have come into contact with the step. Further, the control unit 16 has a step higher than the driving force of at least one of the front wheels 12 on the side estimated to have come into contact with the step or the rear wheels 13 located on the same side in the width direction of the vehicle body of the front wheels 12. The driving force of at least one of the front wheels 12 on the side presumed to be in contact with the vehicle or the rear wheels 13 located on the same side in the width direction of the vehicle body may be increased. Also by these methods, after either the left front wheel or the right front wheel comes into contact with the step, the electrically assisted walking vehicle 10 can be made to face the step. For example, if the step to be overcome is not high, or if the step is slope-shaped, it may be possible to overcome the step without a large driving force. In such a case, it is not necessary to perform the step overcoming control after turning the electrically assisted walking vehicle 10 or to perform the step overcoming control accompanied by the turning of the electrically assisted walking vehicle 10. This simplifies control and allows the user to overcome steps in a shorter period of time.

16 and 17 are plan views showing a second example of the electrically power assisted walking vehicle approaching the step at an angle. 16 and 17 show each step of the operation of the electrically power assisted walking vehicle 10. Hereinafter, the operation of the electrically power assisted walking vehicle 10 will be described with reference to FIGS. 16 and 17.

First, the electrically assisted walking vehicle 10 travels at an angle θ larger than 0 degrees with respect to the step 80 (step S1). At the time of the step S1, the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel are equal. In this case, d _pl > 0, d _pr > 0, or d _pl = d _pr = 0. When d _pl = d _pr = 0, the user is advancing the electrically assisted walking vehicle 10 without any assisting force.

As a result of the electrically assisted walking vehicle 10 advancing from step S1, the right front wheel is in contact with the step 80 (step S2). The determination unit 16a detects a collision with the step 80 of the right front wheel based on the measured value of the measurement unit. _{Then, the control unit 16 controls the drive unit and sets the drive force dpr} in the traveling direction of the right rear wheel, which is the wheel on the side estimated to have come into contact with the step 80, to 0. Further, the control unit 16 may control the braking unit and apply the brake to the right rear wheel. At this time, the driving force of the left rear wheel, which is the wheel on the side estimated not to be in contact with the step 80, is _{set to d pl} > 0. Therefore, the electrically power assisted walking vehicle 10 starts turning (changing direction) to the right.

In this way, the control unit 16 may generate a driving force only in the driving unit of either the front wheel or the rear wheel located on the opposite side in the width direction of the vehicle body from the front wheel that is presumed to have come into contact with the step. .. As a result, the vehicle body can be turned in a short time after one of the front wheels comes into contact with the step.

As a result of turning the electrically assisted walking vehicle 10 to the right, the left front wheel, which is the other front wheel 12, comes into contact with the step 80 (step S3). At this time, the electrically assisted walking vehicle 10 faces substantially the front of the step 80. That is, the above-mentioned angle θ becomes almost equal to 0 degrees. The smaller the angle θ, the smaller the driving force of the electrically power assisted walking vehicle 10 can overcome the step 80. Therefore, the electrically assisted walking vehicle 10 may start the operation of overcoming the step 80 from the time of step S3. That is, if it is estimated that both front wheels have come into contact with the step, the control unit 16 may perform the step overcoming operation. As a result, the electrically assisted walking vehicle 10 can take a more stable posture, so that it is possible to overcome the step 80 without performing complicated control.

For example, if the control unit 16 estimates that both the front wheels 12 have come into contact with the step based on the measured values of the measurement unit, the control unit 16 determines that the width direction of the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle). The driving force of at least one of the front wheels or the rear wheels on both sides of the wheel may be set to be equal. As a result, the driving force of the driving unit can be adjusted so that the turning amount of the electrically assisted walking vehicle 10 does not become too large. Since the assist is performed when the front surface of the electrically assisted walking vehicle 10 faces substantially the front of the step 80, there is an advantage that the step 80 can be overcome more reliably.

The timing at which the left front wheel and the right front wheel (both front wheels) come into contact with the step does not matter. For example, the left front wheel and the right front wheel may come into contact with the step at almost the same time, or the time when the left front wheel touches the step and the time when the right front wheel touches the step may be around. The method of controlling the driving force after the start of the operation of overcoming the step 80 will be described later.

Then, in step S4, the electrically assisted walking vehicle 10 is operating over the step 80. In step S4, in order to assist overcoming the step 80, the driving force d _pr of the right rear wheel, driving force d _pl of the driving force of the left rear wheel is larger than the step S3 previously.

Next, an example of a wheel control method when the electrically power assisted walking vehicle 10 enters at an angle with respect to a step will be described. 18 and 19 are graphs showing an example of a wheel control method for the electrically power assisted walking vehicle 10 (electric vehicle). The horizontal axes of FIGS. 18 and 19 indicate the time. On the other hand, the vertical axis of FIGS. 18 and 19 shows the driving force of the wheel.

The broken line c1 in FIG. 18 shows the driving force of the driving unit connected to the wheel on the opposite side on the side estimated to have come into contact with the step. On the other hand, the broken line c2 indicates the driving force of the driving unit connected to the wheel on the side estimated not to be in contact with the step. For example, assuming that the electrically power assisted walking vehicle 10 having the configurations shown in FIGS. 1 and 2 is used and the right front wheel first contacts the step, the broken line c1 is the driving unit of the driving unit connected to the right rear wheel. Corresponds to. On the other hand, the broken line c2 corresponds to the drive unit of the drive unit connected to the left rear wheel. In the following, the control of FIG. 18 will be described by taking the case where the right front wheel comes into contact with the step as an example.

Electrically assisted walker 10 at time t1 earlier is advanced, the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel are set to be equal. In the example of FIG. 18, d _pl > 0 and d _pr > 0 _{before the time t1, but d pl} = 0 and d _pr = 0 may be used.

Then, at time t1, the right front wheel of the electrically power assisted walking vehicle 10 comes into contact with the step. The determination unit 16a estimates that the right front wheel has collided with the step based on the measured value of the measurement unit. Then, the control unit 16 determines that the step is detected at time t1, gradually increasing the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel after time t1. _{Here, it is estimated that the rate of increase per hour of the driving force dpl} of the drive unit connected to the wheel on the side estimated to have contacted the step (here, the left rear wheel) is not in contact with the step. It is set to be larger than the rate of increase per hour _{of the driving force dpr} of the driving unit connected to the wheel on the other side (here, the right rear wheel).

Then, at time t2, the driving force d _pl Larger left rear wheel of the increase rate per time of the driving force reaches the target value. Here, the target value may or may not be the maximum driving force of the driving unit. _{The control unit 16 maintains the driving force dpl} of the left front wheel after the time t2 at the target value. On the other hand, the driving force d _pr of smaller right rear wheel of the increase rate per time of the driving force at the time t2 has not yet reached the target value. The control unit 16 continues to gradually increase _{the driving force dpr} of the right rear wheel even after the time t2.

At time t3, the driving force d _pr small right rear wheel of the rate of increase per unit time of the driving force also reaches the target value. _{Then, the control unit 16 maintains the driving force dpl} of the left front wheel after the time t3 at the target value.

For example, the control unit 16, electrically assisted walker 10 until it is determined that it has successfully overcome the step, maintaining the driving force d _pr of the left front wheel driving force d _pl and the right rear wheel to the target value. The control unit 16 can determine, for example, whether or not the electrically assisted walking vehicle 10 has succeeded in overcoming the step based on the measured value of the tilt detection sensor 23. Is not particularly limited. As described in FIG. 7 described above, the control unit 16, if it is determined that the electrically assisted walker 10 has successfully overcome the step, to reduce the driving force d _pr of the left front wheel driving force d _pl and the right rear wheel Can be done.

_{Referring to FIG. 18, the relationship of d pl} > d _pr is established between the time t1 and the time t3, and the driving force of the left front wheel continues to be larger than the driving force of the right rear wheel. Therefore, the vehicle body can be turned to the right while the vehicle body of the electrically assisted walking vehicle 10 is raised on the step. As a result, the orientation (angle θ) of the vehicle body of the electrically assisted walking vehicle 10 is corrected after the step is overcome, and the user can move on the step in a safer posture.

The broken line c3 in FIG. 19 shows the driving force of the driving unit connected to the wheel on the opposite side on the side estimated to have come into contact with the step. On the other hand, the broken line c4 indicates the driving force of the driving unit connected to the wheel on the side estimated not to be in contact with the step. For example, assuming that the electrically power assisted walking vehicle 10 having the configurations shown in FIGS. 1 and 2 is used and the right front wheel first contacts the step, the broken line c3 is the driving unit of the driving unit connected to the right rear wheel. Corresponds to. On the other hand, the broken line c4 corresponds to the drive unit of the drive unit connected to the left rear wheel. In the following, the control of FIG. 19 will be described by taking the case where the right front wheel comes into contact with the step first as an example.

Then, at time t1, the right front wheel of the electrically power assisted walking vehicle 10 comes into contact with the step. The determination unit 16a estimates that the right front wheel has collided with the step based on the measured value of the measurement unit. Then, the control unit 16 determines that the step is detected at time t1, gradually increasing the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel after time t1. _{Again, it was estimated that the rate of increase per hour of the driving force dpl} of the drive unit connected to the wheel on the side estimated to have touched the step (here, the left rear wheel) was not touching the step. It is set to be larger than the rate of increase per hour _{of the driving force dpr} of the driving unit connected to the side wheel (here, the right rear wheel).

Increase rate per time of the driving force d _pr of the right rear wheel whereas is set to a constant value, an increase rate per driving force d _pl of time of the left rear wheel is decreased with time .. Therefore, the slope of the broken line c4 after the time t1 is gentle.

At time t3, both the driving force d _pr of the right rear wheel and the driving force d _pl of the left rear wheel reach the target value. The target value may or may not be the maximum driving force of the driving unit. Then, the control unit 16 maintains the driving force d _pl of driving force d _pr and the left rear wheel of the right rear wheel at the time t3 after the target value.

_{Referring to FIG. 19, the relationship of d pl} > d _pr is established between the time t1 and the time t3, and the driving force of the left front wheel continues to be larger than the driving force of the right rear wheel. Therefore, the vehicle body can be turned to the right while the vehicle body of the electrically assisted walking vehicle 10 is raised on the step. As a result, the orientation (angle θ) of the vehicle body of the electrically assisted walking vehicle 10 is corrected after the step is overcome, and the user can move on the step in a safer posture.

As illustrated in the control methods of FIGS. 18 and 19, the control unit 16 has at least one of the front wheels 12 presumed to have come into contact with the step and the front wheels 12 or the rear wheels 13 located on the opposite sides of the vehicle body in the width direction. The driving force of the front wheel 12 and the driving force of at least one of the rear wheels 13 located on the same side of the front wheel 12 in the width direction of the vehicle body, which are presumed to have come into contact with the step, are set as a predetermined threshold. It may be gradually increased until it reaches a value (fourth threshold value or a target value). This makes it possible to prevent the vehicle body from turning excessively.

Further, in the methods of FIGS. 18 and 19, a driving force is also applied to the rear wheels on the side estimated to have collided with the step (the side close to the step) between the time t1 and the time t3. Therefore, it is possible to climb the step by using both rear wheels while turning the vehicle body of the electrically assisted walking vehicle 10. In the methods of FIGS. 18 and 19, the driving forces of the left and right rear wheels are different in the transition period (time t1 to t3) until the driving forces of both rear wheels reach the target value, and the electric power is smoothly applied. The direction of the vehicle body of the assisted walking vehicle 10 can be corrected.

Note that, in the methods of FIGS. 18 and 19, the driving force of both rear wheels may be set equally after detecting that the other front wheel has come into contact with the step. As a result, when the left front wheel and the right front wheel come into contact with the step, the step can be climbed by a large driving force (for example, the driving force of the above-mentioned target value).

As described above, the overcoming operation by the control unit 16 is an operation in which the driving unit increases the driving force of the wheels while turning the vehicle body of the electrically assisted walking vehicle 10 (electric vehicle), or the operation of the electrically assisted walking vehicle 10 (electric vehicle). It may include either an operation in which the driving unit increases the driving force of the wheels after turning the vehicle body, or an operation in which the driving unit increases the driving force of the wheels.

(Use of twin wheel casters)
As shown in the plan view of FIG. 20, the step 80 may be entered in a state where the rotation direction of the front wheels 12 and the rotation direction of the rear wheels 13 of the electrically assisted walking vehicle 10 (electric vehicle) are different. For example, when the electrically assisted walking vehicle 10 changes direction (turns) while moving, the front wheels 12 may face in a direction different from the traveling direction of the vehicle body of the electrically assisted walking vehicle 10.

FIG. 20 is a plan view showing a first example when the front wheels have an angle with respect to the traveling direction of the vehicle body. In step S10 of FIG. 20, both front wheels 12 (left front wheel and right front wheel) of the electrically power assisted walking vehicle 10 collide with the step 80. Each of the front wheels 12 receives _{drags F nl} and F _nr as a reaction of _{the driving force (d pl} + d _pr ) of the rear wheels 13 from the step 80. The drag forces F _nl and F _nr become moments with respect to the rotation center 12r of each front wheel 12, and each front wheel 12 is rotated counterclockwise (counterclockwise).

Due to the rotation, the side surface of the front wheel 12 is oriented so as to be substantially parallel to the step 80 (step S11). In step S11, the rotatable direction of the front wheel 12 is substantially parallel to the step 80. The front wheel 12 can not be rotated in the direction of the step 80, the driving force of the rear wheel 13 _{(d pl,} d _pr) even if the assist by the electric assist walker 10 is difficult over the bump 80 ..

In the example of FIG. 20, the traveling direction of the vehicle body of the electrically assisted walking vehicle 10 is substantially perpendicular to the step 80, but the problem shown here is that the vector of the traveling direction of the vehicle body of the electrically assisted walking vehicle 10 is It also occurs when the angle θ (θ> 0 degree) is set with respect to the perpendicular line of the step 80.

The wheels of the electrically power assisted walking vehicle in the above example were all equipped with single tires. However, the wheels of the electrically power assisted walking vehicle do not necessarily have to be single tires. For example, the front wheels 12 (right front wheel and left front wheel) of the electrically power assisted walking vehicle 10a of FIG. 21 are twin-wheel casters 12a configured to be rotatable.

FIG. 21 is a plan view showing a second example in which the front wheels have an angle with respect to the traveling direction of the vehicle body. In step S20 of FIG. 21, twin wheel casters 12a on both front sides of the electrically power assisted walking vehicle 10a collide with the step 80. Each twin-wheel caster 12a receives _{drag forces F nl} and F _nr as a reaction of _{the driving force (d pl} + d _pr ) of the rear wheels 13 from the step 80. The drag forces F _nl and F _nr are moments with respect to the rotation center 12r of each twin-wheel caster 12a, and each twin-wheel caster 12a is rotated clockwise (clockwise).

The width of the entire wheel of the twin-wheel caster 12a is larger than that of the front wheel 12 of FIG. Therefore, due to the rotation, the contact surface of the casters of the twin-wheel casters 12a becomes substantially parallel to the step 80 (step S21). Therefore, the electrically assisted walking vehicle 10a can overcome the step 80 with the assistance of _{the driving force (d pl} , d _{pr) of the rear wheels 13.}

As shown in the example of FIG. 21, the front wheels of the electrically assisted walking vehicle (electric vehicle) may be twin-wheel casters configured to be rotatable about the vertical axis. It is not always necessary to use twin wheel casters as the front wheels of the electrically power assisted walking vehicle (electric vehicle). For example, by using tires having a tire width wider than that of the rear wheels as the front wheels, it is possible to reduce the probability that it will be difficult to advance the vehicle body as shown in FIG.

(Step detection when using twin wheel casters)
When a twin-wheel caster is used as the front wheel of an electrically assisted walking vehicle (electric vehicle), there is a possibility that the collision between the wheel and the step becomes multi-stage. 22 and 23 are plan views showing an example of a collision between the electrically power assisted walking vehicle 10a and the step. In the following, a multi-step collision with a step will be described with reference to FIGS. 22 and 23.

In the examples of FIGS. 22 and 23, the electrically assisted walking vehicle 10a is approaching the step 80 at an angle θ (θ> 0 degrees). That is, the vertical line of the step 80 and the traveling direction of the electrically assisted walking vehicle 10a form an angle θ. The twin-wheel casters 12a mounted on the front side of the electrically assisted walking vehicle 10a all have an angle with respect to the traveling direction of the electrically assisted walking vehicle 10a. Further, the directions of the left and right twin wheel casters 12a are different.

With reference to step S30, when comparing the magnitude of the angle of the electrically power assisted walking vehicle 10a with respect to the traveling direction, the angle of the right twin wheel caster 12a is larger than that of the left twin wheel caster 12a. First, in step S30, one end of the right twin-wheel caster 12a collides with the step 80. The determination unit 16a detects a collision with the step of the twin wheel caster 12a on the right side based on the measured value of the measurement unit. As a result, the control unit 16 determines that the electrically assisted walking vehicle 10a needs to turn to the right. Then, the control unit 16 controls the driving unit is set larger than the driving force d _pr of the right rear wheel driving force d _pl of the left rear wheel. Therefore, in step S30, the electrically power assisted walking vehicle 10a starts turning to the right.

In the next step S31, one end of the left twin wheel caster 12a collides with the step 80. The determination unit 16a may detect a collision with the step of the left twin wheel caster 12a based on the measured value of the measurement unit. If the collision is detected, it is determined in the control unit 16 and the progress in the vehicle body changes in direction, it is set smaller than before the difference in driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel Good. The control unit 16 may not change the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel in step S31. Regardless driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel, the motor-assisted walker 10a in step S31, it is assumed to continue the right turn.

Then, in step S32, the other end of the right twin-wheel caster 12a collides with the step 80. The determination unit 16a may detect a collision with the step of the twin wheel casters 12a on the right side based on the measured value of the measurement unit. If the collision is detected, it is determined in the control unit 16 and the progress in the vehicle body changes in direction, it is set smaller than before the difference in driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel Good. The control unit 16 may not change the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel in the step S32. Regardless driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel, the motor-assisted walker 10a in step S32, it is assumed to continue the right turn.

Finally, in step S33, the other end of the twin wheel casters 12a of the left twin wheels collides with the step 80. The determination unit 16a detects a collision with the step of the twin wheel caster 12a on the right side based on the measured value of the measurement unit. As a result, the control unit 16 determines that the front surface of the electrically power assisted walking vehicle 10a faces substantially the front surface of the step 80, so that it is no longer necessary to turn the electrically power assisted walking vehicle 10a to the right. Control unit 16 controls the driving unit, sets a driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel to a value equal. Here, the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel of the above FIG 18, may be set to the target value in FIG. 19.

In step S33 subsequent power-assisted walker 10a can perform overcome the step 80 by the assist of the driving force d _pr of the driving force d _pl and the right rear wheel of the left rear wheel.

In the above-mentioned examples of FIGS. 22 and 23, the twin-wheel casters 12a collide with the step a plurality of times before and after the time. Therefore, the impact applied to the electrically assisted walking vehicle 10a is dispersed a plurality of times. Therefore, the acceleration detected by the acceleration sensor 22a may be smaller than that in the case where a single-wheel tire is used for the front wheels. Similarly, when a collision is detected using the speed sensor 22b, the change in speed that occurs in one collision may be smaller than that in the case where a single tire is used for the front wheels. Therefore, when twin-wheel casters are used for the front wheels of an electrically power-assisted walking vehicle (electric vehicle), the threshold value used to detect a collision with a step is set to a smaller value than when the front wheels are single-wheel tires. Can be set. This makes it possible to detect a step.

(Second Embodiment)
Next, a second embodiment of the present disclosure will be described. The second embodiment shown in FIGS. 24 to 30 has different configurations around the rear wheels 13 and the motor 20, and the other configurations are the same as those of the first embodiment described above. In FIGS. 24 to 30, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the configurations shown in FIGS. 24 to 28, the motor 20 of the electrically assisted walking vehicle 10 is connected to each rear wheel 13 via a planetary gear mechanism 50.

As shown in FIGS. 26 to 28, the motor 20 includes a housing 61 fixed to the pipe frame 31, an output shaft support portion 62 housed in the housing 61 and rotatable with respect to the housing 61, and an output shaft. It has an output shaft 63 that is fixed to the support portion 62 and rotates integrally with the output shaft support portion 62. Of these, the flange 64 is fixed to the housing 61, and the output shaft 63 projects from the central portion of the housing 61. A bearing 65 is interposed between the housing 61 and the output shaft support portion 62. Further, a magnet 66 is provided on the outer circumference of the output shaft support portion 62. Further, a coil 67 is arranged around the magnet 66, and the coil 67 is fixed to the housing 61. Electric power from the battery 21 is supplied to the coil 67, and the output shaft support portion 62 provided with the magnet 66 rotates. A cap 68 is provided at the center of the housing 61.

The rear wheel 13 has a wheel 71, a tire 72 provided on the outer circumference of the wheel 71, and a wheel retainer 73 connected to the wheel 71. The wheel 71 is fixed to a bearing 75 provided around the flange 64 via a holding plate 74.

The planetary gear mechanism 50 meshes with the sun gear 51, the internal gear 52 arranged around the sun gear 51, the sun gear 51 and the internal gear 52, and three planets that revolve while rotating when the output shaft 63 rotates. It has a gear 53 and a planetary carrier 54 that rotatably supports the three planetary gears 53 and transmits the revolving motion of the planetary gears 53.

Of these, the sun gear 51 is connected to the output shaft 63 of the motor 20 and can rotate with the rotation of the output shaft 63. Further, the internal gear 52 is connected to the wheel 71 of the rear wheel 13. The planetary carrier 54 is connected to the flange 64 of the motor 20 and is fixed to the pipe frame 31 via the flange 64 and the housing 61.

Subsequently, in the present embodiment, the action of controlling the motor 20 to lift (wheelie) the front wheels 12 with respect to the rear wheels 13 will be described.

First, it is assumed that the front wheels 12 do not collide with the step and the electrically assisted walking vehicle 10 is moving in a normal state. In this case, the assist force from the output shaft 63 of the motor 20 is transmitted from the sun gear 51 connected to the output shaft 63 of the motor 20 to the internal gear 52 via the planetary gear 53, and then connected to the internal gear 52. It is transmitted to the rear wheel 13. As a result, the movement of the rear wheels 13 is assisted by the motor 20. At this time, the pipe frame 31 connected to the planetary carrier 54 does not rotate.

Here, assuming that the number of teeth of the sun gear 51 and the internal gear 52 is Za and Zc (Za <Zc), respectively, and the angular velocities of the sun gear 51, the internal gear 52, and the planet carrier 54 are Wa, Wc, and Wx, respectively, the following Equation (1) holds.
Zc (Wc-Wx) =-Za (Wa-Wx) ... Equation (1)

When the electrically assisted walking vehicle 10 is moving in the normal state, the planet carrier 54 is fixed, so Wx becomes 0. Therefore, the following equation (2) holds.
Wc = (-Za / Zc) Wa ... Equation (2)
That is, the rotation speed of the motor 20 from the output shaft 63 is decelerated to −Za / Zc times and transmitted.

On the other hand, when the front wheel 12 of the electrically assisted walking vehicle 10 collides with a step, the front wheel 12 is locked and the rear wheel 13 also does not rotate. At this time, the internal gear 52 of the planetary gear mechanism 50 connected to the rear wheel 13 is also locked. On the other hand, the rotational force from the output shaft 63 is transmitted to the sun gear 51 connected to the output shaft 63 of the motor 20. This rotational force is transmitted from the sun gear 51 to the planetary carrier 54 via the planetary gear 53, and is in the direction of arrow M (see FIG. 25) with respect to the pipe frame 31 connected to the planetary carrier 54 (electrically assisted walking vehicle 10). A rotational force acts in the direction opposite to the direction of travel.

Therefore, when the front wheel 12 collides with the step, the control unit 16 controls the motor 20 to rotate the entire electrically assisted walking vehicle 10 and lift the front wheel 12 to a position higher than the rear wheel 13. In this case, the control unit 16 may control to increase the output of the motor 20 according to, for example, an operating force (grip force) applied to the handle 14. Specifically, the motor 20 is controlled so that the output of the motor 20 is relatively large even if the operating force is the same as in the normal state (that is, the proportional coefficient of the motor output to the operating force is increased). As a result, the front wheels 12 can be lifted to a position higher than the rear wheels 13.

In this way, when the front wheel 12 of the electrically assisted walking vehicle 10 collides with the step, the internal gear 52 is fixed, so that Wc becomes 0 in the above equation (1). Therefore, the following equation (3) holds.
Wx = {Za / (Zc + Za)} Wa ... Equation (3)
That is, the rotation speed of the motor 20 from the output shaft 63 is decelerated by Za / (Zc + Za) times, and the entire electrically assisted walking vehicle 10 connected to the planetary carrier 54 is in the opposite direction of travel (the side where the front wheels 12 float). ) Will be received.

As described above, according to the present embodiment, the motor 20 is connected to the rear wheel 13 via the planetary gear mechanism 50. As a result, when the front wheel 12 of the electrically assisted walking vehicle 10 collides with the step, the front wheel 12 can be lifted to a position higher than the rear wheel 13 by using the planetary gear mechanism 50. That is, the control unit 16 can make the front wheels 12 wheelie with respect to the rear wheels 13 by the reaction of the planetary gear mechanism 50 by the driving force of the motor 20.

Further, according to the present embodiment, the planetary gear mechanism 50 includes a sun gear 51 connected to the output shaft 63 of the motor 20, an internal gear 52 arranged around the sun gear 51, the sun gear 51, and the inside. It has a planetary gear 53 that meshes with the gear 52 and revolves while rotating when the output shaft 63 rotates, and a planet carrier 54 that rotatably supports the planetary gear 53 and transmits the revolving motion of the planetary gear 53. The internal gear 52 is connected to the rear wheel 13, and the planetary carrier 54 is fixed to the pipe frame 31. As a result, when the front wheels 12 collide with the step, the rotational force from the output shaft 63 of the motor 20 is transmitted from the sun gear 51 to the planetary carrier 54 via the planetary gear 53, and the pipe frame connected to the planetary carrier 54. A rotational force can be exerted on 31. As a result, the entire electrically assisted walking vehicle 10 can be rotated, and the front wheels 12 can be lifted with respect to the rear wheels 13.

In the present embodiment, the control unit 16 has described the case where the front wheels 12 are lifted with respect to the rear wheels 13 by using the planetary gear mechanism 50 as an example. However, the control unit 16 is not limited to the planetary gear mechanism 50, and is not limited to the planetary gear mechanism 50. A mechanism having a gear that revolves while rotating may be used.

Alternatively, instead of the planetary gear mechanism 50, a mechanism including two gears may be used. Specifically, as shown in FIGS. 29 and 30, the first gear 57 is directly connected to the motor 20, the second gear 58 is directly connected to the rear wheel 13, and the first gear 57 and the second gear 58 are directly connected. The gears 58 may be meshed with each other. As shown in FIG. 29, during normal traveling, the movement of the rear wheels 13 is assisted by the motor 20, and the electrically assisted walking vehicle 10 travels. On the other hand, as shown in FIG. 30, for example, when the front wheel 12 collides with the step and the front wheel 12 is locked, the rear wheel 13 is also locked. When the motor 20 further rotates in this state, a force is generated that lifts the entire electrically assisted walking vehicle 10. At this time, a force that rotates in the direction opposite to the traveling direction of the electrically assisted walking vehicle 10 acts. As a result, the front wheels 12 of the electrically assisted walking vehicle 10 can easily get over the step.

(Third Embodiment)
Next, a third embodiment of the present disclosure will be described. The third embodiment shown in FIGS. 31 and 32 is different in that the drive unit that generates the driving force for lifting the front wheel 12 is provided separately from the motor 20, and the other configurations are different. It is the same as the first embodiment described above. In FIGS. 15 and 16, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIGS. 31 (a) and 31 (b), the drive unit that generates the driving force for lifting the front wheel 12 includes an additional motor 46 different from the motor 20. In this case, the rotating shaft of the additional motor 46 may be provided coaxially with the rotating shaft of the rear wheel 13 (FIG. 31 (a)), and is provided on a shaft different from the rotating shaft of the rear wheel 13. It may be (Fig. 31 (b)).

In FIGS. 32 (a) and 32 (b), the drive unit that generates the driving force for lifting the front wheel 12 includes an actuator 47 different from the motor 20. The actuator 47 is connected to the frame 11. In this case, the actuator 47 may be a telescopic type that lifts the front wheel 12 with respect to the rear wheel 13 by expanding and contracting (FIG. 32 (a)), and swings the front wheel 12 to the rear wheel 13. On the other hand, it may be a swing type that lifts (FIG. 32 (b)).

Note that the motor 20 does not necessarily have to be provided in FIGS. 31 and 32.

(Fourth Embodiment)
Next, a fourth embodiment of the present disclosure will be described with reference to FIGS. 33 and 34. In FIGS. 33 and 34, the same parts as those of the first embodiment to the third embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 33 is a schematic perspective view showing an example of the appearance of the electrically assisted walking vehicle (electric vehicle) 10 according to the present embodiment.

(Composition of electrically power assisted walking vehicle)
As shown in FIG. 33, the electrically power assisted walking vehicle 10 includes a frame 11, a pair of front wheels 12 and a pair of rear wheels (wheels) 13 provided on the frame 11, and a pair of handles 14 connected to the frame 11. It has.

A motor 20 that assists the movement of the corresponding rear wheel 13 is connected to the pair of rear wheels 13. A battery 21 and a control unit 16 are attached to the frame 11, respectively. Further, the control unit 16 is provided with a tilt detection sensor 23.

In the present embodiment, a pair of handles 14 operated by the user are provided at the upper ends of the pair of left and right pipe frames 31. The pair of handles 14 are connected to each other by a bar handle 17 extending in the horizontal direction. Further, the pair of handles 14 and the bar handles 17 have a substantially U-shape. Further, an arm support portion 27 on which the user's elbow can be placed is attached to the pair of handles 14. The arm support portion 27 is provided with a hole so that each handle 14 can be inserted, and the handle 14 can be attached to the hole.

A seat portion 37 on which the user can sit is provided between the pair of left and right pipe frames 31 as needed.

The battery 21 supplies electric power to each element of the electrically assisted walking vehicle 10, such as the motor 20 and the control unit 16. The battery 21 is provided below the seat portion 37 located between the pair of pipe frames 31.

Further, the speed sensor (an example of the component related to the measuring unit) 22b is provided on each of the pair of rear wheels 13. The speed sensor 22b is not limited to being built in the pair of front wheels 12 and / or the pair of rear wheels 13, and may be attached to any other member such as the frame 11 and the pair of handles 14. Alternatively, the speed sensor 22b may be arranged in the vicinity of the control unit 16. In the present embodiment, the traveling speed of the electrically assisted walking vehicle 10 is determined based on the rotation speed of the rear wheels 13, but the traveling speed is not limited to this, and the rotation speed of the front wheels 12 or the front wheels 12 and the rear wheels It may be judged based on both rotation speeds of 13.

The measuring unit may be provided with an acceleration sensor 22a. In this case, the acceleration sensor 22a directly measures the acceleration of the electrically assisted walking vehicle 10 without using the rotational acceleration of the rear wheels 13, and transmits a signal of this acceleration to the control unit 16. Then, the control unit 16 calculates the speed by integrating the acceleration.

Further, the measuring unit may be equipped with GPS (Global Positioning System). In this case, GPS detects the position of the electrically power assisted walking vehicle 10 without using the rotational acceleration of the rear wheels 13. Then, the control unit 16 may calculate the speed of the electrically assisted walking vehicle 10 by differentiating the position information from the GPS, and may calculate the acceleration by differentiating the position information from the GPS twice.

The tilt detection sensor 23 includes an acceleration sensor having two or more axes. The tilt detection sensor 23 is provided in the vicinity of the control unit 16. Alternatively, the tilt detection sensor 23 may be provided on the upper part of the electrically assisted walking vehicle 10. Instead of using an acceleration sensor as the tilt detection sensor 23, a gyro sensor may be used to estimate the posture of the electrically power assisted walking vehicle 10.

The other configuration of the electrically assisted walking vehicle 10 is the same as that of the electrically assisted walking vehicle 10 (FIGS. 1 and 2) in the first embodiment.

Further, in the present embodiment, the electrically assisted walking vehicle 10 is not provided with a grip sensor, a strain sensor, a proximity sensor, a pressure sensor, or the like that directly detects whether or not the user has grasped the pair of handles 14. .. However, not limited to this, also in the present embodiment, the grip sensor 24 may be provided on the handle 14 as in the electrically assisted walking vehicle 10 (FIGS. 1 and 2) in the first embodiment.

Although each embodiment and each modification of the present disclosure have been described above, each embodiment and each modification are presented as examples, and the scope of the invention is not intended to be limited. Each embodiment and each modification can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Each embodiment and each modification are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

10, 10a Electric assisted walking vehicle 11 frame 12 Front wheel 13 Rear wheel 14 Handle 15 Brake unit 16 Control unit 20 Motor 21 Battery 22a Accelerometer 22b Speed sensor 23 Tilt detection sensor 24 Grip sensor 25 Leg detection sensor 31 Pipe frame

Claims

A drive unit that drives wheels including at least one of the front wheels and rear wheels provided on the vehicle body.
A control unit that controls the driving unit to overcome the step by causing the wheel to overcome the step.
A measuring unit that measures at least one of the speed and acceleration applied to the vehicle body on which the wheels are provided.
An electric vehicle including a determination unit that determines whether or not the control unit controls overcoming a step based on the measured value of the measurement unit.
The determination unit causes the control unit to control overcoming the step when it is determined that the front wheel has come into contact with the step based on the measured value of the measurement unit.
The electric vehicle according to claim 1.
The step overcoming control includes a control for increasing a driving force for driving the wheel of the driving unit.
The electric vehicle according to claim 1 or 2.
The step overcoming control includes a control for turning the vehicle body.
The electric vehicle according to any one of claims 1 to 3.
The step overcoming control includes a control for increasing a driving force while turning the vehicle body.
The electric vehicle according to any one of claims 1 to 4.
The front wheels include a left front wheel and a right front wheel that are arranged apart from each other in the width direction of the vehicle body.
The determination unit determines whether the left front wheel or the right front wheel has come into contact with the step based on the measured value of the measurement unit.
The electric vehicle according to claim 2.
The measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body or the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body.
The electric vehicle according to claim 6.
The rear wheels include a left rear wheel and a right rear wheel that are arranged apart from each other in the width direction of the vehicle body.
The measuring unit has at least an average value of the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel, or the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel. Calculate the difference between
The electric vehicle according to claim 7.
The measuring unit calculates at least the average value of the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel or the difference between the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel. The electric vehicle according to claim 7 or 8.
The measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body and the acceleration in the width direction of the vehicle body.
The determination unit determines the left front wheel or the left front wheel when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rear direction of the vehicle body measured by the measurement unit becomes equal to or higher than the first threshold value. The electric vehicle according to any one of claims 6 to 9, which estimates which of the right front wheels has come into contact with the step.
The measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body and the acceleration in the width direction of the vehicle body.
The determination unit is within a predetermined period after at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit reaches the first threshold value or more. Claim 6 for estimating whether the left front wheel or the right front wheel comes into contact with the step when the maximum value of the measured absolute value of the acceleration in the width direction of the vehicle body becomes equal to or higher than the second threshold value. The electric vehicle according to any one of 10 to 10.
The measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body.
In the determination unit, at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rear direction of the vehicle body measured by the measurement unit is equal to or greater than the third threshold value smaller than the first threshold value. It is presumed that the left front wheel and the right front wheel touched the step at the time.
The electric vehicle according to claim 10 or 11.
The control unit generates a driving force only in the driving unit of the rear wheel located on the same side in the width direction of the vehicle body of the front wheel estimated to have come into contact with the step.
The electric vehicle according to any one of claims 6 to 12.
The control unit generates a driving force only in at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is presumed to have come into contact with the step. ,
The electric vehicle according to any one of claims 6 to 13.
The control unit is more than the driving force of at least one of the front wheels on the side estimated to be in contact with the step or the rear wheels located on the same side of the front wheels in the width direction of the vehicle body. A large driving force is generated in at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is presumed to have come into contact with the step.
The electric vehicle according to any one of claims 6 to 14.
The control unit is more than the driving force of at least one of the front wheels on the side estimated to be in contact with the step or the rear wheels located on the same side of the front wheels in the width direction of the vehicle body. Any of claims 6 to 15 for increasing the driving force of at least one of the front wheels on the side estimated to have come into contact with the step or the rear wheels located on the same side in the width direction of the vehicle body. The electric vehicle described in the first paragraph.
The control unit contacts the step with the driving force of at least one of the front wheel and the rear wheel located on the opposite side of the front wheel in the width direction of the vehicle body, which is presumed to have contacted the step. The driving force of at least one of the front wheels and the rear wheels located on the same side of the front wheels in the width direction of the vehicle body is gradually increased until the fourth threshold value is reached. ,
The electric vehicle according to any one of claims 6 to 16.
It is presumed that the driving force of at least one of the front wheels and the rear wheels located on the opposite side of the front wheels in the width direction of the vehicle body, which is estimated to have come into contact with the step, has come into contact with the step. It is larger than the driving force of the driving unit of at least one of the front wheels and the rear wheels located on the same side of the front wheels in the width direction of the vehicle body.
The electric vehicle according to claim 17.
The control unit estimates that both of the front wheels come into contact with the step based on the measured values of the measurement unit, and at least one of the front wheels or the rear wheels on both sides in the width direction of the vehicle body. Make the driving force of the driving unit equal.
The electric vehicle according to any one of claims 1 to 18.
The control unit is a condition for executing the overcoming operation of the step when the maximum value of the absolute value of the acceleration in the width direction of the vehicle body measured by the measurement unit becomes the second threshold value or more. The electric vehicle according to any one of claims 1 to 19, wherein the fifth threshold value of acceleration is set small.
The control unit sets a large sixth threshold value of the absolute value of acceleration, which is a condition for executing the overcoming operation of the step as the speed of the vehicle body measured by the measuring unit increases. The electric vehicle according to any one of items 1 to 20.
The measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body.
In the determination unit, the front wheels come into contact with the step when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is larger than the seventh threshold value. I presume that
The electric vehicle according to claim 2.
When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measuring unit is equal to or less than the seventh threshold value, the front wheel becomes a step. Do not presume contact,
The electric vehicle according to claim 22.
A storage unit for storing the measured values of the measurement unit is provided.
The determination unit adjusts the seventh threshold value based on the measured value stored in the storage unit.
The electric vehicle according to claim 22 or 23.
The determination unit detects an acceleration smaller than the seventh threshold value in a predetermined period before the control unit controls the front wheels to overcome the steps after the control unit overcomes the steps of the front wheels. If so, change the 7th threshold to a smaller value.
The electric vehicle according to claim 24.
In the determination unit, the acceleration measured by the measurement unit when the control unit overcomes the step of the front wheel is larger than the seventh threshold value and the difference from the seventh threshold value is a predetermined value. If it is larger, the seventh threshold value is changed to a larger value.
The electric vehicle according to claim 24 or 25.
The measuring unit measures the frequency spectrum of the vibration of the vehicle body and measures the frequency spectrum of the vibration of the vehicle body.
The determination unit estimates that the front wheel has come into contact with the step when the representative value of the value measured by the measurement unit is larger than the eighth threshold value.
The electric vehicle according to claim 2.
The determination unit does not presume that the front wheel has come into contact with the step when the representative value of the value measured by the measurement unit is equal to or less than the predetermined eighth threshold value.
The electric vehicle according to claim 27.
The electric vehicle according to claim 27 or 28, wherein the vibration of the vehicle body includes vibration in the front-rear direction of the vehicle body.
The electric vehicle according to any one of claims 1 to 29, comprising a cushioning member that covers at least a part of the front surface of the vehicle body or both side surfaces in the width direction of the vehicle body.
The electric vehicle according to any one of claims 1 to 30, wherein the front wheels are twin-wheel casters configured to be rotatable.
A drive unit that drives the wheels, including at least one of the front and rear wheels,
A control unit that controls the drive unit and controls overcoming a step,
A measuring unit that measures at least one of the speed and acceleration applied to the vehicle body on which the wheels are provided.
The control unit is provided with a determination unit for determining whether or not to control stepping over the step based on the measured value of the measurement unit.
The control unit controls to increase the driving force for driving the wheels of the driving unit or to turn the vehicle body when the determining unit determines that the front wheels have come into contact with the step based on the measured values of the measuring unit. I do,
Electric vehicle.
A step to measure at least one of the speed or acceleration applied to the vehicle body,
A method for controlling an electric vehicle, which includes a step of determining whether or not to control stepping over a step based on at least one of the speed and the acceleration.
A step of determining whether or not the front wheels have come into contact with a step based on at least one of the speed and the acceleration.
The control method for an electric vehicle according to claim 33, which includes a step of controlling overcoming of the step when it is presumed that the front wheel has come into contact with the step.
33 or 34, wherein the step overcoming control includes at least one of a control for increasing the driving force for driving the wheels, a control for turning the vehicle body, and a control for increasing the driving force while turning the vehicle body. How to control an electric vehicle.
A step to measure at least one of the speed or acceleration applied to the vehicle body,
A step of determining whether or not the front wheels have come into contact with a step based on at least one of the speed and the acceleration.
A control program for an electric vehicle including a step of controlling overcoming of the step when it is presumed that the front wheel has come into contact with the step.
The electric vehicle according to claim 36, wherein the step overcoming control includes at least one of a control for increasing the driving force for driving the wheels, a control for turning the vehicle body, and a control for increasing the driving force while turning the vehicle body. Control program.