KR20120107675A - Electric vehicle and contol method thereof - Google Patents

Abstract

PURPOSE: An electric bicycle and a control method thereof are provided to give continuous driving sense for each inclination to a driver according to the pedaling will of the driver in spite of an electric bicycle without a power transmission device. CONSTITUTION: An electric bicycle comprises an inclination measuring module(200), a pedal rotating speed detection part(100), a driving motor(700), and a control part(500). The inclination measuring module detects the inclination of a driving road. The rotating speed detection part determines the pedaling will of a driver. The driving motor generates driving force for driving a driving wheel according to the pedaling will of the driver detected in the rotating speed detection part. The control part controls the driving force of the driving motor according to the inclination of the driving road detected by the inclination measuring module. [Reference numerals] (100) Pedal rotating speed detection part; (230) Acceleration sensor; (260) Wheel speed sensor; (300) First filter part; (400) Second filter part; (500) Control part; (600) Inverter; (700) Driving motor

Description

Electric bicycle and its control method {ELECTRIC VEHICLE AND CONTOL METHOD THEREOF}

The present invention relates to an electric bicycle, and more particularly, to determine the inclination of the ramp to vary the driving force of the motor accordingly to maintain a continuous driving feeling for each inclination according to the driver's pedal will.

The bicycle is configured such that the front wheel, which is a steering wheel, and the rear wheel, which is a driving wheel, are disposed in a straight line in front and rear of the frame, and the passenger moves forward by rotating the rear wheel by stepping on a pedal interlocked with the rear wheel.

Such a bicycle is provided with a power transmission device such as a chain or a bevel gear that transmits the power generated from the pedal to the rear wheel. In particular, the chain type power train has a drive sprocket wheel installed at one side of the pedal, a driven sprocket wheel installed at the rear wheel which is smaller in diameter than the drive sprocket wheel, and a chain connecting the drive sprocket wheel and the driven sprocket wheel. Consists of Therefore, when the occupant presses the pedal by this structure, the drive sprocket wheel provided integrally with the pedal rotates, and at the same time, the rear wheel connected to the driven sprocket wheel by the chain also rotates to move the bicycle forward.

On the other hand, such a power transmission device has a complicated structure, a large occupied area of a bicycle, and the hem of the occupant is caught or contaminated between the driving sprocket wheel and the chain. In particular, when the multi-stage transmission is installed in the driven sprocket wheel, there is a problem that the chain is frequently separated from the sprocket wheel during shifting.

In recent years, electric bicycles without power trains have been developed and used in view of these problems.

Such an electric bicycle includes a motor for rotating the drive wheels and a battery for supplying power to the motor, and the electric bike is driven in such a manner as to rotate the drive wheels by the motor. At this time, the battery is charged by operating the generator connected to the pedal by rotating the pedal.

However, since the existing electric bicycle does not have a power transmission device, the driver feels pedaling different from that of the pedal when the power transmission device is present.

In particular, in the slopes other than the flat, the driving force of the motor is not reflected well to the driver's pedaling, there was a problem in the electric bicycle running control.

One aspect of the present invention provides an electric bicycle to determine the inclination of the road surface to vary the motor driving force accordingly to maintain a continuous driving feeling for each road inclination according to the driver's pedal will.

To this end, the electric bicycle according to an aspect of the present invention includes an inclination measurement module for detecting the inclination of the road surface; A pedal rotation speed detector for determining a driver's pedal will; A driving motor for generating a driving force for driving the driving wheel according to the pedal will of the driver detected by the pedal rotation speed detection unit; And a controller configured to control a driving force of the driving motor according to the inclination of the road surface detected by the inclination measurement module.

The controller amplifies the output torque of the driving motor at a predetermined ratio when the inclination of the road surface detected through the inclination measurement module has a positive value, and the inclination of the road surface detected through the inclination measurement module is a negative value. In the case of having a, the output torque of the driving motor is reduced at a predetermined ratio.

In addition, when the inclination of the road surface detected through the inclination measurement module has a positive value, the controller increases the gain of the output torque of the driving motor to be greater than 1, and the degree of inclination of the road surface detected through the gradient measurement module. When has a negative value, the gain of the output torque of the drive motor is made smaller than one.

The tilt measurement module also includes an acceleration sensor and a wheel speed sensor.

In addition, the acceleration sensor includes a first acceleration sensor and a second acceleration sensor, the first acceleration sensor is installed at a position 45 degrees in the vertical direction of the travel direction, the second acceleration sensor is 90 in the vertical direction of the first acceleration sensor Is also installed in position.

In addition, the inclination measurement module measures the inclination of the road surface by the ratio of the first acceleration measured by the first acceleration sensor and the second acceleration measured by the second acceleration sensor.

In addition, the ratio between the first acceleration and the second acceleration is equal to the ratio of cosine and sine of the trigonometric function, and the gradient measuring module measures the slope of the driving road through the ratio. .

In addition, when the driving road surface is uneven, the first filter unit for removing the noise component of the acceleration (noise) input to the first acceleration sensor or the second acceleration sensor further comprises a low pass filter (LPF).

In addition, when the first acceleration or the second acceleration, from which the noise is removed through the low pass filter, includes the contamination signal by longitudinal acceleration or deceleration in the driving direction, the wheel speed measured by the wheel speed sensor is differentially calculated. And a second filter unit which removes the longitudinal noise in the driving direction by adding or subtracting the longitudinal acceleration or the longitudinal deceleration to the first acceleration or the second acceleration from which the noise is removed.

An electric bicycle control method according to another aspect of the present invention detects the inclination of the road surface; Detect pedal rotational speed to determine a driver's pedal will; The motor driving force for the driving wheel is controlled according to the pedal will of the driver determined by the detected pedal rotation speed and the detected inclination of the traveling road surface.

In addition, controlling the motor driving force for the driving wheel according to the pedal will of the driver determined by the detected pedal rotation speed and the detected inclination of the traveling road surface,

When the detected slope of the road has a positive value, the output torque of the motor is amplified by a predetermined ratio, and when the detected slope of the road has a negative value, the output torque of the motor is reduced by a predetermined ratio. .

In addition, controlling the motor driving force for the driving wheel according to the pedal will of the driver determined by the detected pedal rotation speed and the detected inclination of the traveling road surface,

If the detected slope of the road surface has a positive value, the gain of the output torque of the motor is greater than 1, and if the detected slope of the road surface has a negative value, the gain of the motor output torque is greater than 1. It is to make it small.

In addition, detecting the inclination of the running road surface measures two accelerations by turning 45 degrees in the vertical direction of the running direction, and measuring the inclination of the running road surface according to the ratio of the measured two accelerations.

In addition, the inclination of the road surface is measured by measuring the slope of the road surface through the ratio of two accelerations equal to the ratio of cosine and sine values of a trigonometric function.

In addition, when the two accelerations include contamination signals by longitudinal acceleration or deceleration with respect to the driving direction, the wheel speed of the driving wheel is measured, and the longitudinal acceleration or longitudinal deceleration calculated by differentiating the measured wheel speed is measured. The method further includes removing longitudinal noise in the driving direction by adding or subtracting two accelerations.

According to the embodiment of the present invention described above, even in the case of an electric bicycle without a power transmission device, it is possible to make the driver feel continuous driving feeling for each inclination according to the driver's pedal will.

1 is a perspective view of an electric bicycle according to an embodiment of the present invention.
2 is a schematic control block diagram of an electric bicycle according to an embodiment of the present invention.
3 is a control block diagram of a control unit according to an embodiment of the present invention.
4 is a graph illustrating a slope-motor torque gain map of a controller according to an embodiment of the present invention.
5 is a schematic view of the installation position of the electric bicycle acceleration sensor according to an embodiment of the present invention.
6 is a graph showing trigonometric functions corresponding to the ratio of the measured acceleration according to the embodiment of the present invention.
7 is a control block diagram illustrating a first filter unit and a second filter unit according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a perspective view showing the configuration of an electric bicycle according to an embodiment of the present invention.

As shown in FIG. 1, an electric bicycle according to an exemplary embodiment of the present invention includes a front frame 10, a center frame 20, a saddle frame 30, and a rear frame 40.

These frames 10, 20, 30, and 40 are coupled to the hinge plate 60 which is sequentially axially coupled by the hinge axis and rotatably provided back and forth around the hinge axis.

One end of the front frame 10 is coupled to the rear of the head tube 13 to which the front wheel 11 and the handle stay 12 to which the handle portion 17 is connected. At this time, the front frame 10 and the head tube 13 may be formed integrally.

The handle portion 17 includes a handle stem 14 coupled to an upper end of the handle stay 12, a handle bar 15 coupled to the handle stem 14, and a handle grip mounted to the handle bar 15. (16).

Here, the handle stem 14 is provided for height adjustment of the handle portion 17. Handlebar 15 is provided to determine the steering of the bicycle. The handle grip 16 is provided with an adjustment unit to adjust the driving speed of the driving motor 700 of the rear frame 40 while simultaneously adjusting the stepping force through the generator 21 of the center frame 20 to be described later. This control unit is electrically connected to the control unit 500.

The front wheel 11 is rotatably coupled to one side of the lower end of the handle stay 12. At this time, in the embodiment of the present invention, the front wheel 11 may be coupled to the lower right side of the handle stay 12 on the basis of when the electric bicycle is viewed from the rear, and the front wheel 11 is in a fork shape like a conventional bicycle. It may be coupled to a handle stay made.

The generator 21 is provided at one end of the center frame 20, and the pedals 23 are rotatably mounted on both sides of the generator 21. That is, when the user rotates the pedal 23, the rotational force of the pedal 23 is converted into electrical energy in the generator 21, and the electrical energy of the generator 21 may be stored in the main battery 45 to be described later. have.

One end of the saddle frame 30 is mounted with a saddle 31 on which the user is seated. The saddle frame 30 can adjust the rotation width around the hinge axis according to the user's physique.

The rear wheel 41 is rotatably mounted on one left side of the rear frame 40.

In addition, the rear wheel 41 may be mounted to the rear frame 40, which is provided in a fork shape like a normal bicycle, although not shown.

The rear wheel 41 is equipped with a drive motor 700 for advancing the bicycle by rotating the rear wheel 41. The drive motor 700 may be equipped with a transmission (not shown) so that a user may change the rotation speed of the rear wheel 41 due to the manipulation of the adjustment unit.

As such, the rear wheel 41 mounted on the left side of the rear frame 40 is in line with the front wheel 11 coupled to the bottom right of the handlestay 12 coupled to the front frame 10 when the folding bicycle is unfolded. It is arranged to be placed.

To this end, the rear frame 40 has a shape bent outward from the other end of the rear frame 40 so that the rear wheel 41 and the front wheel 11 can be arranged in a straight line.

The center of the generator 21 mounted on the center frame 20, that is, the center of the pedal 23 mounted on both sides of the generator 21, and the center of the saddle 31 mounted on the saddle frame 30. And a center of the handle bar 15 connected to the handle stay 12 is disposed in a straight line extending the front wheel 11 and the rear wheel 41. To this end, the center frame 20 may also have a shape bent outward like the rear frame 40.

In addition, the rear frame 40 may have a main battery 45 and a control unit 500 for storing the electrical energy converted by the generator 21.

In this case, the main battery 45 may be embedded in the rear frame 40 as well as in the center frame 20 as described above.

The controller 500 electrically controls the generator 21, the main battery 45, the driving motor 700, and the auxiliary battery 47.

In addition, in the embodiment of the present invention, the main battery 45 as well as detachable from the outside

The external auxiliary battery 47, the main battery 45 and the auxiliary battery 47 provided as possible

It may include a connector 46 for connecting and disconnecting its power. At this time, the connector 46 is disposed on one side of the main battery 45 so that when the auxiliary battery 47 is not mounted, the control unit 500 drives the main battery 45 to drive the driving motor 700. Drive motor 700 to be connected.

In addition, in the embodiment of the present invention, the wire member 71 is provided between the front frame 10 and the center frame 20. The wire member 71 serves to allow each frame 10, 20, 30, 40 to withstand the load generated by the weight of the user.

2 is a schematic control block diagram of an electric bicycle according to an embodiment of the present invention.

In the chainless electric bicycle without a chain connecting the front wheel and the rear wheel according to the embodiment of the present invention, the pedal rotation speed detection unit 100, the inclination measurement module 200, the first filter unit 300, the second filter unit 400 ), A control unit 500, an inverter 600, and a driving motor 700.

The pedal rotation speed detection unit 100 detects the rotation speed of the pedal to determine the pedal will of the electric bicycle driver. Here, the driver's pedal will indicate the speed and force the driver perceives the road condition and exerts on the pedal.

The inclination measurement module 200 detects the inclination of the road surface. The inclination measurement module 200 includes an acceleration sensor 230 and a wheel speed sensor 260.

One or more acceleration sensors 230 may be provided. In the electric bicycle according to the embodiment of the present invention, the acceleration sensor 230 including the first acceleration sensor 233 and the second acceleration sensor 236 may have an inclination measurement module. An example provided at 200 will be described.

The acceleration sensor 230 measures driving acceleration of the electric bicycle. In addition, by including two acceleration sensors 233 and 236, the tilt measurement module 200 can detect the tilt based on the measured two accelerations.

The wheel speed sensor 260 measures the speed of the driving wheel. The wheel speed sensor 260 is a basis for removing noise in the longitudinal direction of the driving direction when the inclination measuring module 200 detects the inclination through the acceleration sensor 230.

The first filter unit 300 removes the noise component of the acceleration input to the acceleration sensor 230. The first filter unit 300 may include a low pass filter LPF.

The second filter unit 400 may be configured to, through the wheel speed sensor 260, when the measurement acceleration from which the noise is removed through the first filter unit 300 includes a contamination signal by longitudinal acceleration or deceleration in the driving direction. The longitudinal acceleration or longitudinal deceleration calculated by differentiating the measured wheel speed is added to or subtracted from the measured acceleration from which the noise is removed to remove the longitudinal noise in the running direction.

The controller 500 controls the driving force of the driving motor 700 according to the pedal rotation speed detected by the pedal rotation speed detection unit 100 and the inclination of the road surface detected by the inclination measurement module 200.

The inverter 600 converts an electrical signal output from the controller 500 into a mechanical signal for applying to the driving motor 700.

The driving motor 700 drives the driving wheels according to the output control signal of the controller 500.

Next, a detailed control process of the controller 500 of the electric bicycle according to an embodiment of the present invention will be described with reference to FIG. 3. 3 is a control block diagram of a control unit according to an embodiment of the present invention.

The controller 500 calculates a gain (gain) of the pedal rotation speed detected by the pedal rotation speed detector 100, and generates a pedal speed-motor torque map based on the gain. The pedal speed-motor torque map shows the required torque (driving force) of the driving motor 700 according to the pedal will of the driver.

In addition, the inclination-motor torque gain map of the inclination measured by the inclination measurement module 200 is generated. The inclination-moto torque gain map represents the required torque (driving force) of the driving motor 700 according to the inclination of the traveling road surface. By multiplying the generated pedal speed-motor torque map by the gradient motor torque gain map, a driving force signal of the driving motor 700 according to the pedal will of the driver and the inclination of the driving road surface is calculated.

The inverter 600 converts a driving force signal of the driving motor 700, which is an electric signal calculated by the control unit 500, into a mechanical signal to be input to the driving motor 700.

The driving motor 700 drives the driving wheels based on the driving force signal input from the inverter 600.

4 is a graph illustrating a slope-motor torque gain map of a controller according to an embodiment of the present invention.

As shown in FIG. 4, the torque gain of the driving motor 700 is adjusted according to the inclination. In the case of a road with a high inclination against the flat driving (up-hill), the control unit 500 amplifies the output torque of the driving motor 700 at a predetermined ratio, and in case of a road with a low inclination compared with the flat driving (down In the case of -hill), the output torque of the driving motor 700 is reduced at a predetermined ratio.

In the case of flat land, the torque of the driving motor 700 is output in accordance with the driver's pedal will. In the case of Up-hill (when the inclination has a positive value), the motor torque gain according to the inclination becomes a value greater than 1 as shown in FIG. 4, and the torque output from the driving motor 700 is amplified. In the case of Down-hill (when the inclination has a negative value), the motor torque gain according to the inclination becomes a value smaller than 1 as shown in FIG. 4, so that the torque output from the driving motor 700 is reduced. In this way, the torque of the driving motor 700 may be adjusted according to the inclination of the road surface and the driver's pedal intention, so that the driver may feel a continuous driving feeling in accordance with the change of the slope of the road surface.

5 is a schematic view of the installation position of the electric bicycle acceleration sensor according to an embodiment of the present invention.

As shown in FIG. 5, the acceleration sensor 230 includes two acceleration sensors, a first acceleration sensor 233 and a second acceleration sensor 236. The first acceleration sensor 233 may be installed to be turned 45 degrees in the vertical direction of the traveling direction of the electric bicycle. In addition, the second accelerometer 236 may be installed by being turned 90 degrees from the installation direction of the first accelerometer 233. Due to the installation direction, the first acceleration sensor 233 and the second acceleration sensor 236 even if the acceleration signal outputted as an acceleration value that may be caused by the inclination of the transverse direction of the traveling direction of the electric bicycle is contaminated by noise. Since noise affects the same, it has the advantage of being robust to the lateral inclination.

The process of detecting the inclination through the first acceleration sensor 233 and the second acceleration sensor 236 will be described through the following equation and a graph shown in FIG. 6.

/4를 중심으로 대칭 값을 갖는다.6 is a graph showing trigonometric functions corresponding to the ratio of the measured acceleration according to the embodiment of the present invention. As shown in FIG. 6, the cos θ graph and the sine θ graph are θ values.

It has symmetry around / 4.

Here, θ represents an inclination, Ax1 represents an acceleration value calculated through the first acceleration sensor 233, and Ax2 represents an acceleration value calculated through the second acceleration sensor 236.

The acceleration range that the first acceleration sensor 233 and the second acceleration sensor 236 can detect is from -45 degrees to +45 degrees. Through the trigonometric equation, the above equation can be satisfied. Specifically, the ratio of acceleration Ax1 and Ax2 measured is equal to the ratio of cosine and sine. Therefore, the slope can be detected through the ratio of the two acceleration values measured. The detected gradient may include noise due to external factors. Hereinafter, the removal of the noise in the gradient detection will be described with reference to FIG. 7.

7 is a control block diagram illustrating a first filter unit and a second filter unit according to an embodiment of the present invention.

As shown in FIG. 7, the gradient measurement module 200 includes a first acceleration sensor 233, a second acceleration sensor 236, and a wheel speed sensor 260.

When measuring the acceleration through the first acceleration sensor 233 and the second acceleration sensor 236, noise may occur due to uneven road surface. At this time, by providing the first filter unit 300 in each of the acceleration sensors 233 and 236, noise can be removed, and more accurate acceleration can be measured. Here, the first filter unit 300 is a part for removing noise, and may be, for example, a low pass filter (LPF).

In addition, there is a noise signal that affects the acceleration sensor 230 by acceleration / deceleration in the longitudinal direction of the electric bicycle driving direction. Such a longitudinal noise signal is obtained by subtracting and decrementing the longitudinal acceleration / deceleration value obtained by differentiating the wheel speed value measured from the wheel speed sensor 260 to the measured acceleration values. Only the acceleration component can be considered. As shown in FIG. 7, the portion for removing the noise signal according to the longitudinal acceleration / deceleration may be represented by the second filter unit 400.

Two acceleration values from which noise is removed may be calculated through the first filter unit 300 and the second filter unit 400, and the ratio of the calculated two acceleration values may be calculated, and finally the slope is obtained through the trigonometric equation. Can be calculated.

100: pedal rotation speed detection unit 200: gradient measurement module
230: acceleration sensor 233: first acceleration sensor
236: second acceleration sensor 260: wheel speed sensor
300: first filter unit 400: second filter unit
500 control unit 600 inverter
700: driving motor

Claims (15)

An inclination measurement module for detecting inclination of the road surface;
A pedal rotation speed detector for determining a driver's pedal will;
A driving motor for generating a driving force to drive the driving wheel in accordance with the pedal will of the driver detected by the pedal rotation speed detection unit;
And a controller for controlling a driving force of the driving motor according to the inclination of the driving road surface detected by the inclination measuring module. The method of claim 1,
The controller amplifies the output torque of the driving motor at a predetermined ratio when the inclination degree of the driving road surface detected by the inclination measuring module has a positive value, and the control unit of the driving road surface detected by the inclination measuring module. The electric bicycle which reduces the output torque of the said drive motor by a predetermined ratio, when the inclination degree has a negative value. The method of claim 2,
When the inclination of the road surface detected by the inclination measuring module has a positive value, the controller increases the gain of the output torque of the driving motor to be greater than 1, and detects the inclination of the driving motor. The electric bicycle which makes the gain of the output torque of the said drive motor smaller than 1, when the inclination of a running road surface has a negative value. The method of claim 1,
The inclination measuring module electric bicycle comprising an acceleration sensor and a wheel speed sensor. The method of claim 4, wherein
The acceleration sensor includes a first acceleration sensor and a second acceleration sensor, the first acceleration sensor is installed at a position 45 degrees in the vertical direction of the driving direction, the second acceleration sensor is a vertical direction of the first acceleration sensor Electric bike installed in the 90 degree position. The method of claim 5,
The inclination measuring module is configured to measure the inclination of the road surface by the ratio of the first acceleration measured by the first acceleration sensor and the second acceleration measured by the second acceleration sensor. The method according to claim 6,
The ratio of the first acceleration and the second acceleration is equal to the ratio of cosine and sine of a trigonometric function,
The inclination measuring module is an electric bicycle for measuring the inclination of the road surface through the ratio. The method of claim 5,
And a first filter unit configured to remove a noise component of the acceleration input to the first acceleration sensor or the second acceleration sensor through a low pass filter (LPF) when the driving road surface is uneven. The method of claim 7, wherein
When the first acceleration or the second acceleration, from which the noise is removed through the low pass filter, includes a contamination signal by longitudinal acceleration or deceleration in the driving direction, the wheel speed measured by the wheel speed sensor is differentiated. And a second filter unit configured to remove longitudinal noise in the driving direction by adding or subtracting the calculated longitudinal acceleration or longitudinal deceleration to the first acceleration or the second acceleration from which the noise is removed. Detecting the inclination of the traveling road surface;
Detect pedal rotational speed to determine a driver's pedal will;
And controlling the motor driving force for the driving wheel according to the pedal will of the driver determined by the detected pedal rotation speed and the inclination of the detected road surface. The method of claim 10,
Controlling the motor driving force for the driving wheel according to the pedal will of the driver determined by the detected pedal rotation speed and the inclination of the detected road surface,
When the detected inclination of the road surface has a positive value, the output torque of the motor is amplified by a predetermined ratio, and when the detected inclination of the road surface has a negative value, the output torque of the motor is predetermined. The electric bicycle control method is to reduce the ratio. The method of claim 11,
Controlling the motor driving force for the driving wheel according to the pedal will of the driver determined by the detected pedal rotation speed and the inclination of the detected road surface,
The gain of the output torque of the motor is greater than 1 when the detected inclination of the traveling road surface has a positive value, and the output of the motor when the detected inclination of the traveling road surface has a negative value. An electric bicycle control method wherein the gain of torque is made smaller than one. The method of claim 10,
Detecting the inclination of the running road surface,
And measuring two accelerations at a 45 degree position in the vertical direction of the driving direction, and measuring the inclination of the driving road surface according to the ratio of the measured two accelerations. The method of claim 13,
The two acceleration ratios are equal to the ratio of cosine and sine values of the trigonometric function,
Detecting the inclination of the running road surface,
And controlling the inclination of the road surface through the ratio. 15. The method of claim 14,
When the two accelerations include a contamination signal by longitudinal acceleration or deceleration with respect to the driving direction, the wheel acceleration of the driving wheel is measured, and the longitudinal acceleration or longitudinal deceleration calculated by differentiating the measured wheel speed is recalled. And removing longitudinal noise for the driving direction by adding or subtracting two accelerations.

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