JP6901276B2 - Electric vehicle - Google Patents

Description

The present invention relates to an electric vehicle for assisting the walking of an elderly person, a physically handicapped person, an inpatient or a person having limited walking.

Conventionally, a walker (silver car, wheelbarrow) that assists the elderly to go out, a walker or other walking assist device has been used to assist the walking of a physically handicapped person or an inpatient. For example, Patent Document 1 discloses a walking assist device capable of performing a straight-ahead / turning motion with a simple operation.

In Patent Document 1, a frame body having a handle portion gripped by a pedestrian, a plurality of wheels provided on the left and right sides of the frame body, a plurality of drive motors for rotationally driving each wheel, and a reverse operation occurring in the drive motor. A pedestrian assisting device (electric vehicle) comprising a control means for detecting an electromotive force and controlling a drive motor based on a counter electromotive force is disclosed.

Japanese Unexamined Patent Publication No. 2009-183407

In such a conventional walking assist device, when the front wheels collide with a step, if the step is low, the front wheels can ride on the step with the assisting force for normal running of the drive motor. However, when the height of the step is high, it is not possible to make the front wheels ride on the step only by the assist force for normal running of the drive motor. In this case, for example, it is necessary for the user to apply a downward force to the steering wheel of the walking assist device to raise the front wheels with respect to the rear wheels so that the front wheels ride on the step. However, such work is a heavy burden for users who have limited walking.

An object of the present invention is to provide an electric vehicle capable of allowing the front wheels to ride on a step without performing an operation that imposes a heavy burden on the user.

The electric vehicle according to the present invention is connected to a frame, front wheels and rear wheels provided on the frame, a drive unit that generates a driving force for raising the front wheels with respect to the rear wheels, and the drive unit. The control unit includes a control unit that controls the drive unit, and the control unit controls the drive unit when it is determined that the front wheels have collided with a step even though the user is trying to advance the electric vehicle. The front wheel is raised with respect to the rear wheel.

In the electric vehicle according to the present invention, when the deceleration of the electric vehicle becomes equal to or higher than the first threshold value, the control unit causes the front wheels to move forward even though the user is trying to advance the electric vehicle. It may be determined that the vehicle has collided with a step.

In the electric vehicle according to the present invention, the control unit attempts to advance the electric vehicle by the user when the electric vehicle is not moving backward after the deceleration becomes equal to or higher than the first threshold value. Nevertheless, it may be determined that the front wheel has collided with the step.

In the electric vehicle according to the present invention, the control unit attempts to advance the electric vehicle by the user when the electric vehicle is moving forward before the deceleration becomes equal to or higher than the first threshold value. Nevertheless, it may be determined that the front wheel has collided with the step.

In the electric vehicle according to the present invention, when the deceleration becomes equal to or higher than the first threshold value and then the traveling speed of the electric vehicle becomes equal to or lower than the second threshold value, the user makes the electric vehicle. It may be determined that the front wheels have collided with the step even though the vehicle is trying to move forward.

In the electric vehicle according to the present invention, a pair of left and right rear wheels are provided, and the control unit advances the electric vehicle when the deceleration of one of the rear wheels becomes equal to or higher than a third threshold value. It may be determined that the front wheel has collided with the step in spite of the attempt to make the vehicle run.

In the electric vehicle according to the present invention, the control unit attempts to advance the electric vehicle when the deceleration of the other rear wheel becomes equal to or higher than a fourth threshold value smaller than the third threshold value. Despite this, it may be determined that the front wheel has collided with the step.

In the electric vehicle according to the present invention, when the deceleration of both rear wheels becomes equal to or higher than the fifth threshold value between the third threshold value and the fourth threshold value, the user can use the electric vehicle. It may be determined that the front wheel has collided with the step even though the vehicle is trying to move forward.

The electric vehicle according to the present invention further includes an operation unit operated by the user, and the control unit uses the electric vehicle when the operation force with respect to the operation unit is equal to or higher than the sixth threshold value. It may be determined that the front wheel has collided with the step even though the vehicle is trying to move forward.

In the electric vehicle according to the present invention, when the control unit determines that the front wheels have collided with the wall surface, it may determine that the front wheels have not collided with the step.

In the electric vehicle according to the present invention, when the brake control is performed on the front wheels or the rear wheels, the control unit does not have to determine whether or not the front wheels have collided with the step.

In the electric vehicle according to the present invention, when the electric vehicle is located on an ascending inclined surface, the control unit does not have to determine whether or not the front wheels have collided with a step.

In the electric vehicle according to the present invention, when the electric vehicle is located on an inclined surface that is inclined to the left or right with respect to the traveling direction, the control unit does not have to determine whether or not the front wheels have collided with a step. Good.

In the electric vehicle according to the present invention, the control unit does not have to determine whether or not the front wheels have collided with the step if the electric vehicle is within a predetermined time after getting over the step.

In the electric vehicle according to the present invention, when the electric vehicle is traveling at a predetermined speed or higher, the control unit does not have to determine whether or not the front wheels have collided with a step.

In the electric vehicle according to the present invention, when the electric vehicle is turning, the control unit does not have to determine whether or not the front wheels have collided with a step.

In the electric vehicle according to the present invention, the front wheels or the rear wheels are provided in pairs on the left and right, and the control unit determines whether or not the front wheels collide with a step when the speed difference between the front wheels or the rear wheels on the left and right is equal to or more than a certain level. It is not necessary to make such a judgment.

In the electric vehicle according to the present invention, in the control unit, the electric vehicle is stopped, the traveling speed of the electric vehicle is below a certain level, or the deceleration of the electric vehicle is equal to or higher than the seventh threshold value. In this case, it may be determined that the front wheel has collided with the step.

The electric vehicle according to the present invention may further include an operation unit operated by the user, and the control unit may determine that the user intends to advance the electric vehicle via the operation unit. ..

In the electric vehicle according to the present invention, the operation unit is a handle connected to the frame and gripped by the user's hand, and the control unit is a handle when the user pushes the handle forward. It may be determined that the user is trying to advance the electric vehicle.

In the electric vehicle according to the present invention, the control unit may determine that the user intends to advance the electric vehicle when the user pushes the steering wheel with a certain force or more.

In the electric vehicle according to the present invention, even if the control unit determines that the user intends to advance the electric vehicle when the user pushes the steering wheel with a force of a certain amount or more for a certain period of time or more. Good.

In the electric vehicle according to the present invention, the drive unit may drive the rear wheels in the forward direction.

In the electric vehicle according to the present invention, the drive unit may be a motor that drives the rear wheels in the forward direction for traveling.

The electric vehicle according to the present invention further includes a handle connected to the frame and gripped by the user's hand, and the control unit increases or decreases the driving force according to the force with which the user pushes the handle. You may.

In the electric vehicle according to the present invention, the control unit gradually increases the driving force after determining that the front wheels have collided with a step even though the user is trying to advance the electric vehicle. You may.

The electric vehicle according to the present invention further includes a handle connected to the frame and gripped by the user's hand, and the control unit increases or decreases the driving force according to the time when the user pushes the handle. You may let me.

In the electric vehicle according to the present invention, the control unit raises the front wheels with respect to the rear wheels, and then controls the drive unit to advance the electric vehicle so that the front wheels come into contact with the upper part of the step. You may.

In the electric vehicle according to the present invention, when the control unit determines that the front wheels have collided with a step, the force for pushing the steering wheel of the user forward is weakened or a force for pulling the steering wheel is applied to the rear. , The driving unit may be controlled to raise the front wheels with respect to the rear wheels.

The electric vehicle according to the present invention further includes an operating means operated by the user, and when the user operates the operating means, the control unit controls the driving unit to shift the front wheels to the rear wheels. It may be raised against.

The electric vehicle according to the present invention further includes a handle that is connected to the frame and is gripped by the user's hand, and a brake lever that brakes the rear wheels when the user operates the control unit. When the user pulls the handle rearward while operating the brake lever, the drive unit may be controlled to raise the front wheel with respect to the rear wheel.

In the electric vehicle according to the present invention, the control unit may gradually reduce the driving force of the rear wheels in the forward direction after raising the front wheels with respect to the rear wheels.

In the electric vehicle according to the present invention, the control unit may gradually reduce the driving force in the forward direction of the rear wheels when the rear wheels rotate.

In the electric vehicle according to the present invention, when the rear wheels rotate, the control unit increases the amount of decrease in the driving force in the forward direction of the rear wheels according to the rotation speed, or increases the amount of decrease in the driving force in the forward direction of the rear wheels. The driving force may be zero.

In the electric vehicle according to the present invention, the control unit raises the front wheels with respect to the rear wheels, and then increases the amount of decrease in the driving force of the rear wheels in the forward direction according to the inclination angle of the electric vehicle. , Or the driving force of the rear wheels in the forward direction may be set to zero.

In the electric vehicle according to the present invention, the control unit has an automatic braking function that automatically brakes the rear wheels when the electric vehicle is on a downhill, and the control unit has the control unit in which the electric vehicle descends. The automatic braking function may be canceled when it is determined that the front wheels have collided with a step even though the user is trying to move the electric vehicle forward on a slope.

The electric vehicle according to the present invention includes a frame, front wheels and rear wheels provided on the frame, and a drive unit for driving the rear wheels, and the drive unit uses a planetary gear mechanism with respect to the rear wheels. The planetary gear mechanism meshes with the sun gear, the internal gear arranged around the sun gear, the sun gear, and the internal gear, and rotates when the output shaft of the drive unit rotates. It has a planetary gear that revolves while rotating, and a planetary carrier that rotatably supports the planetary gear and transmits the revolving motion of the planetary gear. The sun gear is connected to an output shaft of the drive unit, and the sun gear is connected to the output shaft of the drive unit. The internal gear is connected to the rear wheel, and the planetary carrier is fixed to the frame.

The method for controlling an electric vehicle according to the present invention connects a frame, front wheels and rear wheels provided on the frame, a drive unit that generates a driving force for raising the front wheels to the rear wheels, and the drive unit. In the control method of the electric vehicle having the control unit for controlling the drive unit, the control unit determines that the front wheels have collided with the step even though the user is trying to advance the electric vehicle. It is characterized in that the control unit includes a step of controlling the drive unit to raise the front wheels with respect to the rear wheels.

According to the present invention, the front wheels can be raised with respect to the rear wheels and the front wheels can ride on the step without performing an operation that imposes a heavy burden on the user.

FIG. 1 is a perspective view showing an electrically assisted walking vehicle according to the first embodiment of the present invention. FIG. 2 is a side view showing an electrically assisted walking vehicle according to the first embodiment of the present invention. 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 changes in driving force with the passage of time after the front wheels collide with a step. FIG. 8 is a perspective view showing an electrically assisted walking vehicle according to a second embodiment of the present invention. FIG. 9 is a side view showing an electrically assisted walking vehicle according to a second embodiment of the present invention. FIG. 10 is a side view showing the configuration around the rear wheel of the electrically power assisted walking vehicle according to the second embodiment of the present invention. FIG. 11 is a cross-sectional view (FIG. XI-XI cross-sectional view of FIG. 10) showing a configuration around the rear wheels of the electrically power assisted walking vehicle according to the second embodiment of the present invention. FIG. 12 is a cross-sectional perspective view showing a configuration around the rear wheel of the electrically power assisted walking vehicle according to the second embodiment of the present invention. FIG. 13 is a schematic view (during normal running) showing a modified example of the electrically power assisted walking vehicle. FIG. 14 is a schematic view (when the front wheels are locked) showing a modified example of the electrically power assisted walking vehicle. 15 (a) and 15 (b) are schematic views showing an electrically assisted walking vehicle according to a third embodiment of the present invention, respectively. 16 (a) and 16 (b) are schematic views showing an electrically assisted walking vehicle according to a modified example of the third embodiment of the present invention, respectively. FIG. 17 is a perspective view showing an electrically assisted walking vehicle according to a fourth embodiment of the present invention. FIG. 18 is a flowchart for explaining an example of the operation of the control unit according to the fourth embodiment of the present invention.

(First Embodiment)
First, the first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7. In the following description, the same configurations are designated by the same reference numerals. Their names and functions are the same. Therefore, the detailed description of them 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. Further, each handle 14 is provided with a brake unit 15 for manually stopping the electrically power assisted walking vehicle 10.

Motors 20 that assist the movement of the corresponding rear wheels 13 are 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 speed detection sensor 22. 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. 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. Each rear wheel 13 is provided so as to be rotatable in the front-rear direction. As a result, the electrically power assisted walking vehicle 10 can be easily moved forward and backward, and can be easily moved or changed 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. You can also.

In the present embodiment, as the motor 20, any motor such as a servo motor, a stepping motor, an AC motor, a DC motor, or the like can be used, and a speed reducer integrally formed 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 for raising the front wheels 12 with respect to the rear wheels 13. That is, the motor 20 generates a driving force that exerts a moment in the direction of lifting the front wheels 12 on the electrically assisted walking vehicle 10.

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 works as a generator and its resistance is used as a brake. 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. Alternatively, a braking portion for braking the rear wheels 13 may be provided separately from 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 as one on the left and right by the control unit 16, and the left and right motors 20 may be controlled independently as described later. ..

In the present embodiment, the motor 20 is connected to each of the rear wheels 13, but the present invention is not limited to this, and the motor 20 may be connected to all of the pair of front wheels 12 and the pair of rear wheels 13.

The control unit 16 controls the entire electrically assisted walking vehicle 10 such as the motor 20.
In this case, the control unit 16 is provided in the vicinity of the battery 21. The details of the control by the control unit 16 will be described later.

The speed detection sensor 22 detects the rotation speed or speed of the rear wheels 13 and transmits a signal of the rotation speed or speed to the control unit 16. The speed detection sensor 22 is arranged in the vicinity of the control unit 16. The speed detection sensor 22 may be built in the pair of rear wheels 13 of the electrically power assisted walking vehicle 10. Alternatively, the speed detection sensor 22 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.

When the motor 20 is a brushless motor, the speed detection sensor 22 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 detection sensor 22 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. In this case, when the speed detection sensor is composed of the acceleration detection sensor, the speed is calculated by integrating the acceleration. When it is configured by GPS (Global Positioning System), it can be configured to calculate the speed by differentiating the position information.

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 outputs a signal regarding the tilt of the electrically assisted walking vehicle 10 to the control unit 16. Send to. 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 can be used as the tilt detection sensor 23. Further, the posture of the electrically assisted walking vehicle 10 may be detected by using the acceleration detection 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. The leg detection sensor 25 includes 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 an 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) 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 comprises a potentiometer for detecting the movement. To.

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 determines the state of the electrically assisted walking vehicle 10. You can recognize if you have no intention of changing.

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

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 is 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 move the electric vehicle forward through the operation unit", the operation unit is operated by the user pushing or pulling the operation unit with a hand or a part of the body. In addition to the case of detecting the operating force of the user given to the above, the case of detecting the intention of the user by a switch means such as a joystick or a push button is included.

(Action of the present embodiment)
Next, the operation of the present embodiment having such a 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 even though the user is trying to advance the electrically assisted walking vehicle 10. In this case, first, based on the detection signals from the gripping sensors 24 provided on the pair of left and right handles 14, the control unit 16 causes the pair of left and right handles 14 to perform a certain force or more for a certain period of time (for example, 1 second or more). It is determined whether or not the button is pressed (step S1).

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 more accurately determine 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 pressed by a force, and in other cases, it may be determined that the handle 14 is pressed 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 more accurately.

Here, when the pair of handles 14 are not pushed by a certain force or more (No in step S1), 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 S1), 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 S2).

Specifically, the speed detection sensor 22 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 predetermined speed 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 S2), 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 rear wheel 13 is not driven, that is, the rear wheel 13 is stopped (the electrically assisted walking vehicle 10 is stopped) or is moving at a predetermined speed V or less (electrically). When the traveling speed of the assisted walking vehicle 10 is equal to or less than a certain level (No in step S2), the control unit 16 determines that the front wheels 12 have collided with the step. At this time, the control unit 16 controls the motor 20 and gradually increases or decreases the driving force of the motor 20 according to, for example, a force pushing the handle 14 (an operating force applied to the handle 14). Since the electrically assisted walking vehicle 10 cannot move forward because the front wheels 12 collide with the step, 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, and the front wheels It acts to make 12 stand out.

When the control unit 16 determines that the user is trying to move the electrically assisted walking vehicle 10 forward, the control unit 16 uses the time and force that the handle 14 is pressed as described above to allow the user to move forward. It is possible to accurately judge what is being done and avoid judgments that are 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 raise 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 more accurately determine 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) when 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 (seventh threshold value), it may be determined that the front wheels 12 have collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward. 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 grip sensor 24 does not necessarily have to be provided. 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 allows the user to walk electrically assisted. It may be determined that the front wheels 12 have collided with the step even though the vehicle 10 is trying to move forward. Thereby, it is possible to accurately determine 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.

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 step can be climbed on. If the front wheel 12 does not rise here, the user subsequently weakens the force for pushing the steering wheel 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 that opposes 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 is increased, and the front wheel 12 acts to be lifted.

If the front wheel 12 still does not rise, the user subsequently pulls the steering wheel 14 backward. At this time, the force pulling the steering wheel 14 backward generates a moment in the direction of lifting the front wheel 12, 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 walking vehicle 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 backward by the user, the user may lift the front wheel 12 by stepping on a pedal (not shown) fixed to the rear of the rotation shaft of the rear wheel 13.

At this time, as the front wheels 12 float with respect to the rear wheels 13, a gap is generated between the front wheels 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 part of the step. As a result, the front wheel 12 can be smoothly driven onto the step.

After raising the front wheels 12, 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 at which the reduction of the driving force is started is a predetermined condition when the control unit 16 controls the drive unit in order to raise the front wheel 12 (despite the fact that the user is trying to advance the electrically assisted walking vehicle 10). It can be set when the 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 raised 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 floated together with the driving force of the motor 20. it can. As a result, the front wheels 12 can easily get over the step without the user lifting the electrically assisted walking vehicle 10. As described above, the front wheels 12 may be floated only by increasing the driving force of the motor 20 without necessarily having the user pull the handle 14 backward, such as when the step is low.

By the way, as described above, 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 wheels 12 are raised with respect to the rear wheels 13, the control unit 16 determines that the front wheels 12 have overcome the step. The electrically assisted walking vehicle 10 may not be accelerated any more. In this case, the control unit 16 controls the motor 20 to further 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 alternate long and short dash 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 becomes a certain value or more (because the electrically assisted walking vehicle 10 tilts when the front wheel 12 climbs a step).

(2) When the rotation speed of the rear wheel 13 detected by the speed detection sensor 22 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 is trying to move the electric vehicle 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 and (ii) the electrically assisted walking vehicle 10 are provided. Output from the strain gauge, (iii) tire pressure of the front wheel 12 or rear wheel 13, (iv) acceleration in the front-rear direction of the electrically power assisted walking vehicle 10, (v) pressure sensor provided on the handle 14, etc. One or a plurality of elements selected from the output, (vi) the output from the myoelectric sensor provided on the handle 14 and the like, and (vii) the movement of the user's foot may be considered.

As described above, according to the present embodiment, when it is determined that the front wheels 12 have collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward, the control unit 16 uses the motor. 20 is controlled to raise the front wheels 12 with respect to the rear wheels 13. As a result, the front wheel 12 can easily get over the step without performing an operation that imposes a heavy burden on the user.

Further, according to the present embodiment, the control unit 16 determines that the front wheels 12 have collided with the step when the rear wheels 13 are stopped or the speed of the rear wheels 13 is equal to or less than a certain value V. As a result, it is possible to appropriately detect that the front wheel 12 has collided with the step. Further, the existing speed detection sensor 22 can detect that the front wheel 12 has collided with the step.

Further, according to the present embodiment, the control unit 16 determines that the user is trying to advance the electrically assisted walking vehicle 10 via the handle 14 (operation unit). As a result, the user operates the steering wheel 14 as usual without performing any special operation, and the control unit 16 appropriately determines that the user is trying to advance the electrically assisted walking vehicle 10. Can be done.

Further, according to the present embodiment, the control unit 16 determines that the user intends to move the electrically assisted walking vehicle 10 forward when the user pushes the steering wheel 14 forward. As a result, the control unit 16 attempts to advance the electrically assisted walking vehicle 10 by the user performing a simple operation of pushing the steering wheel 14 forward as usual without performing a special operation. You can properly judge that you are there.

Further, according to the present embodiment, the control unit 16 determines that the user intends to move the electrically assisted walking vehicle 10 forward when the user pushes the steering wheel 14 with a certain force or more. As a result, it is possible to quickly detect that the user is trying to move the electrically assisted walking vehicle 10 forward, and the user can raise the front wheel 12 without significantly reducing the walking speed. Further, the existing grip sensor 24 can detect that the user is trying to move the electrically assisted walking vehicle 10 forward.

Further, according to the present embodiment, the control unit 16 determines that the user intends to move the electrically assisted walking vehicle 10 forward when the user pushes the handle 14 with a certain force or more for a certain period of time or more. To do. As a result, it is possible to accurately determine that the user is trying to move the electrically assisted walking vehicle 10 forward, and to avoid a determination that is different from the intention of the user.

Further, according to the present embodiment, the motor 20 that raises the front wheels 12 with respect to the rear wheels 13 drives the rear wheels 13 in the forward direction, so that the rear wheels 13 can be lifted without using a separate lifting means or the like. It can be used to smoothly lift the front wheel 12.

Further, according to the present embodiment, the motor 20 that raises the front wheels 12 with respect to the rear wheels 13 drives the rear wheels 13 in the forward direction for traveling, so that the motor for traveling the rear wheels 13 The front wheel 12 can be lifted smoothly by using the 20.

Further, according to the present embodiment, since the control unit 16 increases or decreases the driving force according to the force by which the user pushes the handle 14, the motor 20 according to the intention of the user according to the operating force with respect to the handle 14. Appropriate driving force can be obtained.

Further, according to the present embodiment, the control unit 16 increases or decreases the driving force according to the time when the user pushes the handle 14, so that the driving force of the motor 20 is generated while the user pushes the handle 14. Since it gradually increases or decreases, it is possible to generate an appropriate driving force (a small driving force for a low step and a large driving force for a high step) according to the height of the step.

Further, according to the present embodiment, the control unit 16 raises the front wheels 12 with respect to the rear wheels 13 and then controls the motor 20 to advance the electrically assisted walking vehicle 10 to move the front wheels 12 into steps. Since it is brought into contact with the upper part, the front wheel 12 can smoothly ride on the step.

Further, according to the present embodiment, when the control unit 16 determines that the front wheel 12 has collided with the step, the force for pushing the steering wheel 14 of the user forward is weakened or a force for pulling backward is applied. At the same time, since the motor 20 is controlled to lift the front wheels 12 with respect to the rear wheels 13, the front wheels 12 can be reliably lifted by utilizing the operating force of the steering wheel and the driving force of the motor 20.

Further, according to the present embodiment, the control unit 16 raises the front wheels 12 with respect to the rear wheels 13 and then gradually reduces the driving force of the rear wheels 13 in the forward direction. As a result, it is possible to prevent sudden acceleration immediately after the lifted front wheel 12 is brought into contact with the ground again.

Further, according to the present embodiment, the control unit 16 gradually reduces the driving force in the forward direction of the rear wheels 13 when the rear wheels 13 rotate. As a result, the control unit 16 can determine that the front wheel 12 has been lifted when the rear wheel 13 starts to rotate.

Further, according to the present embodiment, when the rear wheels 13 rotate, the control unit 16 increases the amount of decrease in the driving force in the forward direction of the rear wheels 13 according to the rotation speed, or increases the amount of decrease in the driving force of the rear wheels 13. The driving force in the forward direction is set to zero. As a result, when the rotation speed of the rear wheels 13 suddenly increases, the driving force of the rear wheels 13 can be significantly reduced to prevent sudden acceleration of the electrically assisted walking vehicle 10 or idling of the rear wheels 13. it can.

Further, according to the present embodiment, after the front wheels 12 are lifted with respect to the rear wheels 13, the control unit 16 applies a driving force in the forward direction of the rear wheels 13 according to the inclination angle of the electrically assisted walking vehicle 10. The amount of reduction is increased, or the driving force of the rear wheels 13 in the forward direction is set to zero. As a result, it is possible to prevent the electric assisted walking vehicle 10 from backflip when the electrically assisted walking vehicle 10 is tilted by an allowable angle or more. Further, the grip of the user pushes the steering wheel 14 forward as the electrically assisted walking vehicle 10 tilts backward, and it is possible to prevent the control unit 16 from driving the motor 20 regardless of the intention of the user.

(Modified example of the method of raising the front wheel)
Next, each modification of the method in which the control unit 16 controls the motor 20 to raise the front wheels 12 with respect to the rear wheels 13 will be described.

(Modification example 1)
In the above, the case where the control unit 16 automatically determines that the front wheel 12 has collided with the step has been described as an example, but in addition to this, the user determines whether or not the front wheel 12 has collided with the step. The front wheel 12 may be raised with respect to the rear wheel 13 according to the operation of.

In this case, the user first manually operates the brake lever 34 and then pulls the handle 14 backward. At this time, the control unit 16 recognizes that the brake lever 34 has been operated by a sensor (not shown), and also recognizes that the handle 14 has been pulled backward based on the detection signal from the grip sensor 24.

At this time, the control unit 16 raises (willies) the front wheels 12 with respect to the rear wheels 13 by increasing the output of the motor 20, for example, in the same manner as described above. After that, the user pushes the pair of handles 14 with the front wheels 12 raised 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. During this time, the user holds the brake lever 34 in a manually operated state.
After the front wheel 12 has climbed over the step, the user releases the brake lever 34. By performing such an operation, the control unit 16 can correctly recognize whether the user is trying to get over the step or the user is trying to move the electrically assisted walking vehicle 10 backward.

The method for causing the control unit 16 to recognize whether or not the user is trying to raise the front wheel 12 is not limited to the user operating the brake lever 34, but is another method that the control unit 16 can recognize. May be used. For example, when the user operates an operating means such as a push button switch (not shown) provided on the handle 14, the control unit 16 may control the motor 20 to raise the front wheels 12 with respect to the rear wheels 13. ..

According to this modification, the user can generate a moment around the rear wheels by pulling the handle 14 backwards, so that the front wheels 12 can be easily floated together with the driving force of the motor 20. be able to. As a result, the front wheels 12 can easily get over the step without the user lifting the electrically assisted walking vehicle 10. Further, according to the present modification, even when the front wheels 12 do not necessarily collide with the step, the front wheels 12 can be raised with respect to the rear wheels 13 as needed. In particular, when the front wheel 12 is lifted by operating the brake lever 34, the front wheel 12 can be smoothly lifted by using the brake lever 34 without the need to separately provide a special operating means.

(Modification 2)
The electrically assisted walking vehicle 10 according to this modification has a function (automatic braking function) of automatically braking the rear wheels 13 so that the electrically assisted walking vehicle 10 does not accelerate too much when it is on a downhill. ing. On the other hand, it is conceivable that the front wheels 12 collide with the step while the electrically assisted walking vehicle 10 is traveling downhill.

In this modification, the control unit 16 determines that the front wheel 12 has collided with the step even though the electrically assisted walking vehicle 10 is on a downhill and the user is trying to advance the electrically assisted walking vehicle 10. At that time, the automatic braking function is canceled. After that, the control unit 16 increases the output of the motor 20, for example, and increases the driving force of the rear wheels 13 in the forward direction in the same manner as described above. The control unit 16 determines whether or not the electrically assisted walking vehicle 10 is on a downhill based on a signal from the inclination detection sensor 23.

According to this modification, it is possible to prevent a problem that the front wheel 12 becomes difficult to get over a step due to the automatic braking function working.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The second embodiment shown in FIGS. 8 to 14 has different configurations around the rear wheels 13 and the motor 20, and the other configurations are substantially the same as those of the first embodiment described above. In FIGS. 8 to 14, 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 configuration shown in FIGS. 8 to 12, 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. 10 to 12, 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 periphery 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 raise (willie) 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 planetary carrier 54 are Wa, Wc, and Wx, respectively, the following Equation (1) holds.
Zc (Wc-Wx) =-Za (Wa-Wx) ... Equation (1)

When the electrically power assisted walking vehicle 10 is moving in the normal state, the planetary 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 wheels 12 of the electrically assisted walking vehicle 10 collide with a step, the front wheels 12 are locked and the rear wheels 13 also do 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. 9) 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 wheels 12 collide with the step, the control unit 16 controls the motor 20, so that 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 this case, the control unit 16 may be controlled to increase the output of the motor 20 according to, for example, the 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 raised with respect to 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 wheels 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 with respect to the rear wheel 13 by using the planetary gear mechanism 50. That is, the control unit 16 can lift (wheelie) the front wheels 12 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 raised 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, but 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. 13 and 14, 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. 13, 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. 14, 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 so that the entire electrically assisted walking vehicle 10 is lifted. 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 power assisted walking vehicle 10 can easily get over the step.

(Third Embodiment)
Next, a third embodiment of the present invention will be described. The third embodiment shown in FIGS. 15 and 16 is different in that the drive unit that generates the driving force for raising the front wheel 12 is provided separately from the motor 20, and has another configuration. Is substantially 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. 15A and 15B, the driving unit that generates the driving force for raising the front wheel 12 is an additional motor 46 different from the motor 20. In this case, the rotation shaft of the additional motor 46 may be provided coaxially with the rotation shaft of the rear wheel 13 (FIG. 15A), and is provided on a shaft different from the rotation shaft of the rear wheel 13. It may be (Fig. 15 (b)).

In FIGS. 16A and 16B, the driving unit that generates the driving force for raising the front wheel 12 is composed of 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 of a telescopic type in which the front wheel 12 is lifted with respect to the rear wheel 13 by expanding and contracting (FIG. 16A), and the front wheel 12 is moved to the rear wheel 13 by swinging. It may be a swing type that floats up with respect to (FIG. 16 (b)).

In addition, in FIG. 15 and FIG. 16, the motor 20 does not necessarily have to be provided.

(Fourth Embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIGS. 17 and 18. In FIGS. 17 and 18, the same parts as those in the first to third embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 17 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. 17, 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.

Motors 20 that assist the movement of the corresponding rear wheels 13 are 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 be seated 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 power 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 detection sensor (detection unit) 22 is provided on each of the pair of rear wheels 13. The speed detection sensor 22 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 a frame 11, a pair of handles 14, or any other member. Alternatively, the speed detection sensor 22 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.

Alternatively, the detection unit may be composed of an acceleration detection sensor. In this case, the acceleration detection sensor directly detects 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. Further, the control unit 16 is configured to calculate the speed by integrating the acceleration.

Further, the detection unit may be configured by 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. Further, the control unit 16 may be configured to calculate the speed of the electrically power assisted walking vehicle 10 by differentiating the position information from the GPS, and calculate the acceleration by differentiating the position information from the GPS twice. it can.

The tilt detection sensor 23 includes acceleration detection sensors 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 the acceleration detection sensor as the tilt detection sensor 23, the posture of the electrically assisted walking vehicle 10 may be detected by using a gyro sensor.

The other configuration of the electrically assisted walking vehicle 10 is substantially 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.

(Action of the present embodiment)
Next, the operation of the present embodiment having such a configuration will be described. FIG. 18 is a flowchart for explaining an example of the operation of the control unit 16.

(Whether or not step mode is possible)
First, the control unit 16 determines whether or not the control to the electrically power assisted walking vehicle 10 enters the step mode (step S11 in FIG. 18). Here, the step mode is a state that is a prerequisite for the control unit 16 to determine whether or not the front wheel 12 has collided with the step, as will be described later. In other words, when the control unit 16 has not shifted to the step mode, the control unit 16 determines whether or not the front wheel 12 has collided with the step for reasons such as improving safety or preventing false detection. Do not do. Therefore, except for the step mode, the control unit 16 does not control the front wheels 12 to float with respect to the rear wheels 13.

The control unit 16 considers the following conditions (A-1) to (A-7) in determining whether or not to shift to the step mode. In this case, the control unit 16 prevents the mode from shifting to the step mode when any one of the following conditions (A-1) to (A-7) is satisfied. However, not limited to this, the control unit 16 may not shift to the step mode when the following conditions (A-1) to (A-7) are satisfied.

<Condition (A-1)>
When the brake control is performed on the front wheels 12 or the rear wheels 13, the control unit 16 may not shift to the step mode (do not determine whether the front wheels 12 have collided with the steps). ..

For example, when the motor 20 is used as a reverse brake, or when a fall prevention brake is applied and the electrically assisted walking vehicle 10 suddenly stops, the control unit 16 erroneously detects that the front wheels 12 have collided with a step. there is a possibility. Therefore, when the brake is applied to prevent the fall, it is preferable that the control unit 16 does not shift to the step mode.

Further, for example, when the control unit 16 is on a flat ground having a small running resistance and the user simply puts his / her hand on the grip unit 42 (see FIGS. 1 and 2), the user releases his / her hand from the handle 14. It is also conceivable that the motor 20 is controlled to suddenly stop the electrically assisted walking vehicle 10 by erroneously detecting that the vehicle has done so. Even in such a case, it is preferable that the control unit 16 does not shift to the step mode in order to prevent erroneous detection that the front wheel 12 has collided with the step.

Further, for example, when the user operates the brake lever 34 or the like (see FIGS. 1 and 2), the rear wheel 13 may suddenly stop and the handle 14 may be pushed. Even in such a case, it is preferable that the control unit 16 does not shift to the step mode in order to prevent erroneous detection that the front wheel 12 has collided with the step.

In this way, when the brake control is performed on the front wheels 12 or the rear wheels 13, the control unit 16 erroneously detects that the front wheels 12 have collided with the step by preventing the vehicle from shifting to the step mode. Can be prevented.

<Condition (A-2)>
When the electrically assisted walking vehicle 10 is located on an ascending inclined surface, the control unit 16 may not shift to the step mode (do not determine whether or not the front wheel 12 has collided with the step). The control unit 16 can determine whether or not the electrically assisted walking vehicle 10 is located on an ascending inclined surface based on a signal from the inclined detection sensor 23.

For example, if the rear wheel 13 collides with the step after the front wheel 12 has overcome the step, the step is located at the user's feet. Therefore, since it is dangerous for the electrically assisted walking vehicle 10 to enter the step mode and accelerate, it is preferable not to assist to increase the output of the motor 20. Further, it is preferable for safety that the electrically assisted walking vehicle 10 cannot climb the stairs. In order to prevent the mode from shifting to the step mode in such a situation, it is preferable not to shift to the step mode when the front wheel 12 has an inclination equal to or higher than the presumed climbing on the step.

As described above, the control unit 16 can further improve the safety by preventing the electrically assisted walking vehicle 10 from shifting to the step mode when the electrically assisted walking vehicle 10 is located on an ascending inclined surface.

<Condition (A-3)>
When the electrically assisted walking vehicle 10 is located on an inclined surface that is inclined to the left or right with respect to the traveling direction, the control unit 16 does not shift to the step mode (it does not determine whether or not the front wheel 12 has collided with the step). You may do so.

For example, if the electrically assisted walking vehicle 10 is located on the step slope and accidentally gets over the edge of the side portion of the step slope or the like, the electrically assisted walking vehicle 10 may fall or the like. Therefore, when the electrically assisted walking vehicle 10 is on an inclined surface that is inclined to the left or right with respect to the traveling direction, it is preferable not to shift to the step mode.

In this way, when the electrically power assisted walking vehicle 10 is located on an inclined surface that is inclined to the left or right with respect to the traveling direction, the control unit 16 can further enhance safety by preventing the vehicle from shifting to the step mode. it can.

<Condition (A-4)>
The control unit 16 does not shift to the step mode (does not determine whether or not the front wheel 12 has collided with the step) within a predetermined time after the electrically assisted walking vehicle 10 has overcome the step. Is also good.

As described above (condition (A-2)), when the rear wheel 13 gets over the step or when the front wheel 12 collides with the stairs, the step mode is not changed. Therefore, the work of the electrically assisted walking vehicle 10 overcoming the step is not continuously performed. In addition, it is dangerous to shift to the step mode again and make a vibrating movement by the impact after failing to get over the step. Therefore, it is preferable not to shift to the step mode again within a predetermined time after the electrically assisted walking vehicle 10 has overcome the step.

As described above, the control unit 16 can further improve the safety by preventing the electrically assisted walking vehicle 10 from shifting to the step mode within a predetermined time after overcoming the step.

<Condition (A-5)>
When the electrically assisted walking vehicle 10 is traveling at a predetermined speed or higher, the control unit 16 may not shift to the step mode (do not determine whether or not the front wheel 12 has collided with the step).

If the front wheels 12 of the electrically power assisted walking vehicle 10 collide with a step at high speed, the rear wheels 13 are likely to float, and if the front wheels 12 get over the steps, the user may stumble, which is dangerous. Therefore, if the front wheels 12 collide with a step while the electrically assisted walking vehicle 10 is traveling at a predetermined speed or higher, it is preferable not to shift to the step mode.

As described above, the control unit 16 can further improve the safety by preventing the electrically assisted walking vehicle 10 from shifting to the step mode when the electrically assisted walking vehicle 10 is traveling at a predetermined speed or higher.

<Condition (A-6)>
When the electrically assisted walking vehicle 10 is turning, the control unit 16 may not shift to the step mode (it does not determine whether or not the front wheel 12 has collided with the step).

As will be described later (see condition B-5 below), it is preferable that the front wheels 12 can overcome the step even when only one of the front wheels 12 of the pair of front wheels 12 collides with the step. However, when the electrically power assisted walking vehicle 10 is turning, or when the casters of the front wheels 12 are caught, it may be erroneously determined that the front wheels 12 have collided with the step. Therefore, for example, when the speed difference between the left and right front wheels 12 or the rear wheels 13 is equal to or greater than a predetermined value, the control unit 16 determines that the electrically power assisted walking vehicle 10 is turning and does not shift to the step mode. It is preferable to do so.

In this way, the control unit 16 prevents the front wheel 12 from erroneously detecting that the front wheel 12 has collided with the step by preventing the electrically assisted walking vehicle 10 from shifting to the step mode when the walking vehicle 10 is turning. Can be done.

<Condition (A-7)>
When the speed difference between the pair of left and right front wheels 12 or the rear wheels 13 is equal to or greater than a certain level, the control unit 16 may not shift to the step mode (do not determine whether the front wheels 12 have collided with the step). ..

For example, in the electrically assisted walking vehicle 10 provided with the grip sensor 24 (see FIGS. 1 and 2), the motor 20 is in the assisted state when the handle 14 is pressed. In such a case, if one of the rear wheels 13 is floating and idle, a speed difference will occur between the left and right front wheels 12 or the rear wheels 13. Therefore, it is preferable that the control unit 16 does not shift to the step mode because the front wheels 12 or the rear wheels 13 are idling when the speed difference between the pair of left and right front wheels 12 or the rear wheels 13 is equal to or more than a certain level.

In this way, when the speed difference between the pair of left and right front wheels 12 or the rear wheels 13 is equal to or greater than a certain level, the control unit 16 prevents the vehicle from shifting to the step mode so that the front wheels 12 or the rear wheels 13 are idling. It is possible to prevent a problem that the front wheel 12 is erroneously detected as having collided with a step.

(Judgment as to whether the front wheels collided with a step)
When all of the above conditions (A-1) to (A-7) are not satisfied, the control unit 16 shifts to the step mode. Subsequently, the control unit 16 determines whether or not the front wheel 12 has collided with the step even though the user is trying to advance the electrically assisted walking vehicle 10 (step S12 in FIG. 18).

In this case, the control unit 16 considers the following conditions (B-1) to (B-9). For example, in the control unit 16, when all of the following conditions (B-1) to (B-9) are satisfied, the front wheels 12 have a step, even though the user is trying to move the electrically assisted walking vehicle 10 forward. It is judged that it collided with. Not limited to this, the control unit 16 determines that the front wheel 12 has collided with the step when one or more (part) of the following conditions (B-1) to (B-9) are satisfied. You may.

<Condition (B-1)>
When the deceleration of the rear wheels 13 exceeds the threshold value (first threshold value), the control unit 16 causes the front wheels 12 to collide with the step even though the user is trying to advance the electrically assisted walking vehicle 10. You may judge that you did.

That is, when the front wheels 12 collide with the step, the electrically assisted walking vehicle 10 suddenly stops, and the rear wheels 13 are decelerated (negative acceleration). By detecting the deceleration of the rear wheels 13, it is possible to detect that the front wheels 12 have collided with the step. The deceleration threshold value (first threshold value) of the rear wheel 13 should be set to a size that does not erroneously detect that the vehicle has collided with a step when the electrically assisted walking vehicle 10 is suddenly stopped by the user's force. Is preferable. Further, the deceleration of the rear wheels 13 may be determined based on the number of rotations of the respective rear wheels 13, or may be determined using the acceleration sensors attached to the left and right rear wheels 13.

In this way, when the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value), the control unit 16 determines the front wheels 12 even though the user is trying to advance the electrically assisted walking vehicle 10. By determining that the vehicle has collided with the step, it is possible to detect that the front wheel 12 has collided with the step by a simple method without using, for example, the grip sensor 24.

<Condition (B-2)>
In the control unit 16, in addition to the condition (B-1), after the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value) (deceleration occurs), the rotation speed of the rear wheels 13 becomes a negative threshold value. In the above case (the electrically assisted walking vehicle 10 is not moving backward), it is determined that the front wheel 12 has collided with the step even though the user is trying to advance the electrically assisted walking vehicle 10. Is also good.

Based on the above condition (B-1), when it is determined whether or not the front wheel 12 has collided with the step based only on the deceleration of the front wheel 12, the front wheel 12 has collided with the step when the handle 14 is pulled backward. May be falsely detected. Therefore, after the deceleration of the rear wheel 13 becomes equal to or higher than the threshold value (first threshold value), the rotation speed of the rear wheel 13 becomes equal to or higher than the negative threshold value. When a person pulls the handle 14 backward, it is possible to prevent a problem of erroneously detecting that the front wheel 12 has collided with the step. The negative threshold value is preferably a value close to zero.

As described above, in the control unit 16, after the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value), the rotation speed of the rear wheels 13 becomes equal to or higher than the negative threshold value (electrically assisted walking vehicle 10). Is not moving backward), it is determined that the front wheel 12 has collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward. As a result, it is possible to more reliably detect that the front wheel 12 has collided with the step.

<Condition (B-3)>
In addition to the condition (B-2), the control unit 16 has a positive rotation speed of the rear wheels 13 before the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value) (deceleration occurs). In the case (the electrically assisted walking vehicle 10 is moving forward), it may be determined that the front wheels 12 have collided with the step even though the user is trying to advance the electrically assisted walking vehicle 10.

In particular, in the case of the electrically assisted walking vehicle 10 not provided with the grip sensor 24, it is difficult to determine whether or not the user intends to advance the electrically assisted walking vehicle 10. Therefore, the user will advance the electrically assisted walking vehicle 10 based on the fact that the electrically assisted walking vehicle 10 has advanced forward (the rotation speed of the rear wheels 13 is positive) before the deceleration occurs. You may judge that it is.

As described above, in the control unit 16, the rotation speed of the rear wheels 13 is positive (electrically assisted walking vehicle) before the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value) (deceleration occurs). When 10 is moving forward), it is determined that the front wheel 12 has collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward. As a result, it is possible to more reliably detect that the user was trying to advance the electrically assisted walking vehicle 10 when the front wheel 12 collided with the step.

<Condition (B-4)>
In the control unit 16, after the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value), the rotation speed of the rear wheels 13 (running speed of the electrically assisted walking vehicle 10) is equal to or lower than the positive threshold value (second threshold value). In the case of, it may be determined that the front wheel 12 has collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward.

When the front wheels 12 collide with a step, the speed of the rear wheels 13 becomes almost zero. However, for example, when the speed of the rear wheel 13 is calculated by the pulse from the Hall element, even if the actual speed of the rear wheel 13 is zero, the speed calculated from the Hall element does not immediately become zero. Therefore, when the rotation speed of the rear wheel 13 is equal to or less than the positive threshold value (second threshold value), it is determined that the front wheel 12 has collided with the step, so that the front wheel 12 has collided with the step more accurately. Can be detected.

As described above, in the control unit 16, after the deceleration of the rear wheels 13 becomes equal to or higher than the threshold value (first threshold value), the rotation speed of the rear wheels 13 (running speed of the electrically assisted walking vehicle 10) becomes a positive threshold value (first threshold value). When it is less than or equal to 2 threshold values, it is determined that the front wheels 12 have collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward. As a result, it is possible to more accurately detect that the front wheel 12 has collided with the step.

<Condition (B-5)>
The control unit 16 causes the user to advance the electrically assisted walking vehicle 10 when the deceleration of one of the left and right rear wheels 13 becomes equal to or higher than a threshold value (third threshold value). However, it may be determined that the front wheel 12 has collided with the step.

When both the pair of left and right front wheels 12 collide with the step, a large deceleration occurs for both the pair of left and right rear wheels 13. However, when the electrically power assisted walking vehicle 10 approaches the step in a state of being slightly slanted in a plan view, it is conceivable that only one of the front wheels 12 collides with the step. In such a case, the rear wheel 13 on the collision side causes a large deceleration, but the front wheel 12 on the non-collision side has room to move, so that the rear wheel 13 on the non-collision side decelerates. Tends to be smaller. Even in such a case, in order to reliably detect that the front wheels 12 have collided with a step, the deceleration of one of the left and right rear wheels 13 is a threshold value (third threshold value). It is preferable that the above conditions are the conditions under which the front wheels 12 collide with the step. The deceleration of the rear wheels 13 may be calculated not from the rotation speed of the rear wheels 13 but by using the front-rear components of the acceleration sensors attached to the left and right rear wheels 13.

In this way, the control unit 16 allows the user to use the electrically assisted walking vehicle 10 when the deceleration of one of the left and right rear wheels 13 becomes equal to or greater than a threshold value (third threshold value). It is determined that the front wheel 12 has collided with the step even though the vehicle is trying to move forward. As a result, even when the electrically assisted walking vehicle 10 approaches the step diagonally in a plan view, it is possible to accurately detect that the front wheel 12 has collided with the step.

<Condition (B-6)>
In addition to the condition (B-5), the control unit 16 determines that the deceleration of the other rear wheel 13 of the pair of left and right rear wheels 13 becomes a threshold value smaller than the third threshold value (fourth threshold value) or more. It may be determined that the front wheel 12 has collided with the step even though the user is trying to move the electrically assisted walking vehicle 10 forward.

When one of the pair of left and right front wheels 12 collides with a step, the other rear wheel 13 decelerates to a certain extent. Therefore, on condition that the deceleration of the other rear wheel 13 is equal to or higher than the threshold value (fourth threshold value), the front wheel 12 collides with the step when the electrically assisted walking vehicle 10 turns lightly. It is possible to prevent false detection. The deceleration of the rear wheels 13 is not limited to the calculation from the rotation speed of the rear wheels 13, and may be calculated by using the front-rear components of the acceleration sensors attached to the left and right rear wheels 13.

In this way, when the deceleration of the other rear wheel 13 of the pair of left and right rear wheels 13 becomes equal to or greater than a threshold value smaller than the third threshold value (fourth threshold value), the control unit 16 is electrically driven by the user. It is determined that the front wheel 12 has collided with the step even though the assisted walking vehicle 10 is trying to move forward. As a result, when the electrically assisted walking vehicle 10 turns lightly, it is possible to prevent erroneous detection that the front wheel 12 has collided with the step.

<Condition (B-7)>
When the deceleration of both the left and right rear wheels 13 becomes equal to or greater than the threshold value (fifth threshold value) between the third threshold value and the fourth threshold value, the control unit 16 advances the electrically assisted walking vehicle 10 by the user. It may be determined that the front wheel 12 has collided with the step in spite of the attempt.

That is, it may be a condition that the deceleration of both the left and right rear wheels 13 exceeds a medium threshold value (fifth threshold value).

In this way, when the deceleration of both the left and right rear wheels 13 becomes equal to or greater than the threshold value (fifth threshold value) between the third threshold value and the fourth threshold value, the control unit 16 allows the user to use the electrically assisted walking vehicle. It is determined that the front wheel 12 has collided with the step even though the 10 is trying to move forward. As a result, even when the left and right front wheels 12 collide with the step at almost the same time, this can be accurately determined.

It should be noted that the collision of the front wheels 12 with the step may be determined by whether or not the sum of the decelerations of the left and right rear wheels 13 is equal to or greater than a predetermined threshold value.

<Condition (B-8)>
When the operating force on the steering wheel 14 is equal to or greater than the threshold value (sixth threshold value), the control unit 16 causes the front wheels 12 to collide with the step even though the user is trying to advance the electrically assisted walking vehicle 10. You may judge that you did.

When the electrically assisted walking vehicle 10 is provided with the grip sensor 24 (FIGS. 1 and 2), when the front wheels 12 collide with the step, at least the grip portion 42 located on the side that collides with the step is pushed in by the reaction force. Will be. Therefore, it may be a condition for determining that the front wheel 12 has collided with the step that the grip force on the side that detects the large deceleration of the left and right is equal to or more than the threshold value. By providing this condition, for example, when the electrically assisted walking vehicle 10 collides with an object while the user releases the handle 14, the electrically assisted walking vehicle 10 moves forward due to an inclined surface or inertia. In the event of a collision with a step, it is possible to prevent the front wheels 12 from being controlled to float with respect to the rear wheels 13.

In this way, when the operating force with respect to the steering wheel 14 is equal to or greater than the threshold value (sixth threshold value), the control unit 16 has the front wheels 12 even though the user is trying to advance the electrically assisted walking vehicle 10. Judges that it has collided with a step. As a result, when it is not necessary to raise the front wheel 12, the front wheel 12 can be prevented from rising with respect to the rear wheel 13.

<Condition (B-9)>
When the control unit 16 determines that the front wheels 12 have collided with the wall surface, the control unit 16 may determine that the front wheels 12 have not collided with the step.

When the front wheel 12 collides with the step, the electrically assisted walking vehicle 10 tends to jump up due to the influence of the drag force from the step or the influence of the rotational inertia of the front wheel 12. When the front wheel 12 collides with a normal step, the downward acceleration applied to the electrically assisted walking vehicle 10 does not exceed the gravitational acceleration. On the other hand, when the front wheel 12 collides with the wall surface, a large downward acceleration is applied to the electrically assisted walking vehicle 10 due to the friction between the front wheel 12 and the wall surface. Therefore, when the acceleration in the vertical direction with respect to the electrically assisted walking vehicle 10 is equal to or higher than the threshold value, it is considered that the front wheels 12 have collided with the wall surface, and the front wheels 12 are prevented from rising with respect to the rear wheels 13. In addition, the control unit 16 provides a switch or a distance measuring sensor that detects a step above a predetermined height located in front of the front wheel 12, and the front wheel 12 is placed on the wall surface based on a signal from the switch or the distance measuring sensor. It may be determined that the collision has occurred.

In this way, when the control unit 16 determines that the front wheels 12 have collided with the wall surface, the control unit 16 determines that the front wheels 12 have not collided with the step. As a result, when the front wheel 12 collides with the wall surface, the front wheel 12 can be prevented from rising with respect to the rear wheel 13.

As described above, when any of the above conditions (B-1) to (B-9) is not satisfied (No in step S12 of FIG. 18), the control unit 16 raises the front wheels 12 with respect to the rear wheels 13. Do not control.

On the other hand, when all of the above conditions (B-1) to (B-9) are satisfied (Yes in step S12 of FIG. 18), the control unit 16 tries to move the electrically assisted walking vehicle 10 forward. It is determined that the front wheel 12 has collided with the step in spite of the presence. At this time, the control unit 16 controls the motor 20 to raise the front wheels 12 with respect to the rear wheels 13.

During this period, a certain waiting time is provided in order to reliably determine that the front wheels 12 have collided with the step. During this standby time, when all of the above conditions (B-1) to (B-9) are satisfied, the control unit 16 gradually increases the driving force of the rear wheels 13 by the motor 20. After that, when the assist force of the rear wheel 13 reaches the maximum value, that state is maintained for a certain period of time. After that, the control unit 16 ends the step mode regardless of whether or not the front wheel 12 has overcome the step.

Since the operation after the control unit 16 determines that the front wheel 12 has collided with the step is substantially the same as that of the first embodiment, detailed description thereof will be omitted here.

Although each embodiment and each modification of the present invention 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 Electric assisted walking vehicle 11 Frame 12 Front wheel 13 Rear wheel 14 Handle 15 Brake unit 16 Control unit 20 Motor 21 Battery 22 Speed detection sensor 23 Tilt detection sensor 24 Grip sensor 25 Leg detection sensor 31 Pipe frame

Claims (35)

With the frame
The front 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.
A control unit connected to the drive unit and controlling the drive unit is provided.
In the control unit, when the deceleration of the electric walking assist device is equal to or higher than the first threshold value and the deceleration is equal to or higher than the first threshold value, and then the electric walking assist device is not moving backward, the user can use the control unit. despite the attempts to advance the electric walking assist device judges that the front wheel collides with the step, the front wheel by controlling the drive unit lifted relative to the rear wheel,
The control unit is characterized in that it does not control the front wheels to float with respect to the rear wheels when the electric walking assist device is moving backward after the deceleration reaches the first threshold value or more. Electric walking assist device . Although the control unit is trying to advance the electric walking assist device when the electric walking assist device is advanced before the deceleration becomes equal to or higher than the first threshold value, the user is trying to advance the electric walking assist device. without electric walking assist device of claim 1, wherein the front wheel is characterized in that it is determined that a collision with the step. In the control unit, when the traveling speed of the electric walking assist device is equal to or less than the second threshold after the deceleration becomes equal to or higher than the first threshold value, the user advances the electric walking assist device. The electric walking assist device according to claim 1 or 2 , wherein it is determined that the front wheel has collided with a step in spite of the attempt to make the vehicle run. A pair of left and right rear wheels are provided, and the control unit attempts to advance the electric walking assist device when the deceleration of one of the rear wheels becomes equal to or higher than a third threshold value. The electric walking assist device according to any one of claims 1 to 3 , wherein it is determined that the front wheels have collided with a step. The control unit is trying to advance the electric walking assist device when the deceleration of the other rear wheel becomes equal to or higher than a fourth threshold value smaller than the third threshold value. The electric walking assist device according to claim 4 , wherein it is determined that the front wheel has collided with a step. When the deceleration of both rear wheels becomes equal to or higher than the fifth threshold value between the third threshold value and the fourth threshold value, the control unit attempts to advance the electric walking assist device by the user. The electric walking assist device according to claim 5 , wherein it is determined that the front wheel has collided with a step in spite of the fact that the front wheel has collided with the step. The control unit further includes an operation unit operated by the user, and the control unit attempts to advance the electric walking assist device when the operation force with respect to the operation unit is equal to or higher than the sixth threshold value. The electric walking assist device according to any one of claims 1 to 6 , wherein it is determined that the front wheel has collided with a step in spite of the fact that the front wheel has collided with the step. The electric walking assist according to any one of claims 1 to 7 , wherein when the control unit determines that the front wheels have collided with a wall surface, it determines that the front wheels have not collided with a step. Equipment . Any of claims 1 to 8 , wherein the control unit does not determine whether or not the front wheels have collided with a step when brake control is performed on the front wheels or the rear wheels. The electric walking assist device according to item 1. Any of claims 1 to 9 , wherein the control unit does not determine whether or not the front wheel has collided with a step when the electric walking assist device is located on an ascending inclined surface. The electric walking assist device according to paragraph 1. The control unit does not determine whether or not the front wheels have collided with a step when the electric walking assist device is located on an inclined surface that is inclined to the left or right with respect to the traveling direction. The electric walking assist device according to any one of 1 to 10 . Wherein, the case electric walking assist device is within a predetermined time period after over a bump, of claims 1 to 11, characterized in that the front wheel does not perform determination of whether a collision with the step The electric walking assist device according to any one of the items. Any of claims 1 to 12 , wherein the control unit does not determine whether or not the front wheels have collided with a step when the electric walking assist device is traveling at a predetermined speed or higher. The electric walking assist device according to paragraph 1. The control unit according to any one of claims 1 to 13 , wherein the control unit does not determine whether or not the front wheel has collided with a step when the electric walking assist device is turning. Electric walking assist device . The front wheels or the rear wheels are provided in pairs on the left and right, and the control unit does not determine whether or not the front wheels have collided with a step when the speed difference between the front wheels or the rear wheels on the left and right is equal to or greater than a certain level. The electric walking assist device according to any one of claims 1 to 14 . In the control unit, when the electric walking assist device is stopped, the traveling speed of the electric walking assist device is below a certain level, or the deceleration of the electric walking assist device is equal to or higher than the seventh threshold value. The electric walking assist device according to any one of claims 1 to 15 , wherein it is determined that the front wheel has collided with a step. Further provided with an operation unit operated by the user
Wherein the control unit, the electric walking assistance according to any one of claims 1 to 16, and determines that the user via the operation unit is attempting to advance the electric walking assist device Equipment . The operation unit is a handle that is connected to the frame and is gripped by the user's hand.
Wherein the control unit, the electric walking of claim 17 wherein the user when pressing the handle forward, the user is and determines that is trying to advance the electric walking assist device Auxiliary device . 18. The control unit according to claim 18 , wherein the control unit determines that the user intends to advance the electric walking assist device when the user pushes the steering wheel with a force equal to or higher than a certain level. Electric walking assist device . The control unit is characterized in that when the user pushes the steering wheel with a force of a certain amount or more for a certain period of time or more, the control unit determines that the user intends to advance the electric walking assist device. 18. The electric walking assist device according to 18. The electric walking assist device according to any one of claims 1 to 20 , wherein the drive unit drives the rear wheels in the forward direction. The electric walking assist device according to claim 21 , wherein the drive unit is a motor that drives the rear wheels in a forward direction for traveling. Further provided with a handle connected to the frame and gripped by the user's hand.
The electric walking assist device according to claim 22 , wherein the control unit increases or decreases the driving force according to a force by which the user pushes the handle. The control unit is characterized in that the driving force is gradually increased after determining that the front wheels have collided with a step even though the user is trying to advance the electric walking assist device. The electric walking assist device according to claim 22 . Further provided with a handle connected to the frame and gripped by the user's hand.
The electric walking assist device according to claim 22 , wherein the control unit increases or decreases the driving force according to the time when the user pushes the steering wheel. The control unit is characterized in that after the front wheels are lifted with respect to the rear wheels, the front wheels are brought into contact with the upper part of the step by controlling the drive unit and advancing the electric walking assist device. The electric walking assist device according to claim 22 . When the control unit determines that the front wheel has collided with a step, the control unit controls the drive unit in accordance with a force that pushes the steering wheel forward of the user or a force that pulls the steering wheel backward. The electric walking assist device according to claim 18 , wherein the front wheels are raised with respect to the rear wheels. Further provided with an operating means operated by the user,
The electric walking assist according to claim 1, wherein the control unit controls the drive unit to raise the front wheels with respect to the rear wheels when the user operates the operation means. Equipment . A handle connected to the frame and gripped by the user's hand,
Further provided with a brake lever that brakes the rear wheels when operated by the user.
The claim is characterized in that when the user pulls the steering wheel rearward while operating the brake lever, the control unit controls the drive unit to raise the front wheels with respect to the rear wheels. Item 1. The electric walking assist device according to item 1. 22. The electric walking assist device according to claim 22, wherein the control unit raises the front wheels with respect to the rear wheels and then gradually reduces the driving force of the rear wheels in the forward direction. The electric walking assist device according to claim 30 , wherein the control unit gradually reduces the driving force in the forward direction of the rear wheels when the rear wheels rotate. When the rear wheels rotate, the control unit increases the amount of decrease in the driving force in the forward direction of the rear wheels according to the rotation speed, or makes the driving force in the forward direction of the rear wheels zero. 30. The electric walking assist device according to claim 30. After raising the front wheels with respect to the rear wheels, the control unit increases the amount of decrease in the driving force in the forward direction of the rear wheels according to the inclination angle of the electric walking assist device, or the rear wheels. The electric walking assist device according to claim 22 , wherein the driving force in the forward direction of the vehicle is set to zero. The control unit has an automatic braking function that automatically brakes the rear wheels when the electric walking assist device is on a downhill.
The control unit automatically determines that the front wheel has collided with a step even though the electric walking assist device is on a downhill and the user is trying to advance the electric walking assist device. The electric walking assist device according to claim 22 , wherein the braking function is released. 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 unit that is connected to the drive unit and controls the drive unit. In the control method of the electric walking assist device having
When the deceleration of the electric walking assist device becomes the first threshold value or more and the deceleration becomes the first threshold value or more, and then the electric walking assist device does not move backward, the user The process of determining that the front wheel has collided with a step even though is trying to advance the electric walking assist device.
The control unit includes a step of controlling the drive unit to raise the front wheels with respect to the rear wheels .
The control unit is characterized in that it does not control the front wheels to float with respect to the rear wheels when the electric walking assist device is moving backward after the deceleration reaches the first threshold value or more. How to control the electric walking assist device.

Images