JP2016158308A - Motor control device and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive motor control device and motor control method for reducing a load on a person without using a sensor in acquiring the information of a drive system.SOLUTION: A motor control device 80 and a motor control method are constituted to calculate the value Fxs of man power to work on a vehicle 10 on the basis of an inter-terminal voltage U of a motor 12 and a current value I of a current flowing down the motor 12. The motor 12 is controlled based on the man power Fxs. Consequently, an expensive sensor for acquiring the information of a drive system such as a torque sensor is not required so as to extremely inexpensively configure the motor control device 80 to be used in an electrically-driven assist device. Thus, the electrically-driven assist device for automatically controlling the torque of the motor in response to a load is extremely inexpensively provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor control device and a motor control method for an electric assist device that assists in running a vehicle powered by human power.

  There are many vehicles such as wheelchairs, trolleys, and bicycles that are moved by human power. And these vehicles increase the load on a person, for example, uphill. On the other hand, in recent years, wheelchairs and bicycles having an electric assist device having driving wheels that are rotated by a motor have been commercialized. Some of these electric assist devices include a motor control device as shown in the following [Patent Document 1] that automatically controls the rotational force of the motor according to the load.

JP 09-099017 A

  However, the conventional motor control device shown in [Patent Document 1] requires an expensive sensor such as a torque sensor, and there is a problem that the device configuration is complicated and the cost is high.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inexpensive motor control device and motor control method that do not use a sensor for acquiring drive system information.

The present invention
(1) A motor control device for the drive wheel 14 that assists the traveling of the vehicle 10 powered by human power,
A speed control unit 30 for controlling the voltage U between terminals of the motor 12 of the drive wheel 14 in accordance with the target speed Vref of the vehicle 10;
A speed observer unit 32 for obtaining an inter-terminal voltage U output from the speed control unit 30 and a current value I flowing down the motor 12 to calculate an angular velocity ω of the drive wheel 14;
A disturbance observer unit 34 for estimating a human power value Fxs acting on the vehicle 10 based on the angular velocity ω calculated by the velocity observer unit 32 and the current value I;
An admittance control unit 36 that sets a target speed Vref of the vehicle 10 based on a human power value Fxs estimated by the disturbance observer unit 34 and feeds it back to the speed control unit 30. By providing the above, the above-described problems are solved.
(2) The speed observer unit 32 includes the terminal voltage U and the current value I, the previously acquired gear ratio gr of the reduction gear of the motor 12, the winding resistance R of the motor 12, and the back electromotive force constant of the motor 12. The angular velocity ω of the driving wheel is calculated from Ke based on the following [Equation 1],
The disturbance observer 34 includes the angular velocity ω, the terminal voltage U, the radius r of the motor 12, the vehicle viscous resistance coefficient Dw, the gear ratio gr of the reduction gear, the torque constant Kτ of the motor 12, and the motor. Moment of inertia J, viscous resistance coefficient Dm of the motor, gravitational acceleration g, weight m of input or preset vehicle 10 and load, rolling friction constant c of vehicle 10, angle θ of the slope, From the following [Equation 7], the human power value Fxs is estimated,
The admittance control unit 36 uses the human force value Fxs estimated by the disturbance observer unit 34, the virtual mass M that is arbitrarily set and related to the load on the person and the response speed to the driving wheel 14 and the virtual damping coefficient D as follows: The above problem is solved by providing the motor control device 80 according to the above (1), wherein the target speed Vref of the vehicle 10 is set based on the equation (10).
(3) By providing the motor control device 80 according to the above (2), further including a filter unit 38 that removes a rapid fluctuation component of the human power value Fxs output by the disturbance observer unit 34. Solve the problem.
(4) A motor control method for the drive wheel 14 that assists the traveling of the vehicle 10 powered by human power,
VI acquisition step of acquiring a voltage U between terminals of the motor 12 of the drive wheel 14 and a current value I flowing down the motor 12;
An angular velocity calculating step of calculating an angular velocity ω of the drive wheel 14 based on the inter-terminal voltage U acquired in the VI acquiring step and the current value I;
A human power estimation step of estimating a human power value Fxs acting on the vehicle 10 based on the angular velocity ω calculated in the angular velocity calculation step and the current value I;
A target speed setting step for setting a target speed Vref of the vehicle 10 based on the human power value Fxs estimated in the human power estimation step;
And a control step for controlling the voltage U between the terminals of the motor 12 based on the target speed Vref set in the target speed setting step. Solve.
(5) The angular velocity calculation step includes the terminal voltage U and the current value I, the previously acquired gear ratio gr of the reduction gear of the motor 12, the winding resistance R of the motor 12, and the back electromotive force constant Ke of the motor 12. Based on the following [Equation 1], the angular velocity ω of the driving wheel is calculated,
The human power estimation step includes the angular velocity ω, the terminal voltage U, the radius r of the motor 12 acquired in advance, the viscosity resistance coefficient Dw of the vehicle, the gear ratio gr of the reduction gear, the torque constant Kτ of the motor 12, and the motor 12 Moment of inertia J, the viscous resistance coefficient Dm of the motor 12, the gravitational acceleration g, the weight m of the input or preset vehicle 10 and the load, the rolling friction constant c of the vehicle 10 and the angle θ of the slope. Based on the following [Equation 7], the human power value Fxs is estimated,
The target speed setting step includes the following values from the human power value Fxs estimated by the human power estimation step, the virtual mass M that is arbitrarily set and related to the load on the person and the response speed to the drive wheel 14 and the virtual damping coefficient D: The above problem is solved by providing the motor control method according to (4) above, wherein the target speed Vref of the vehicle 10 is set based on the equation (10).
(6) The motor control method according to (5), further including a filter step for removing a sudden fluctuation component of the human power value Fxs obtained in the human power estimation step. Solve.
(7) The virtual damping coefficient D is composed of the difference E (n) between the human power value Fxs (n) sequentially input and the target load Fxd and the learning gain, and the learning is performed so that the difference E (n) becomes small. The motor control method according to (5) or (6), further including a learning step of sequentially changing a gain and optimizing the virtual damping coefficient D.

  The motor control device and the motor control method according to the present invention do not require a sensor for collecting information of a drive system such as a motor. Thereby, the motor control apparatus which assists human power can be provided at low cost.

It is a block diagram which shows the motor control apparatus which concerns on this invention. It is a model figure which shows the force applied to a vehicle on a slope. It is a block diagram of a motor control device concerning the present invention.

  Embodiments of a motor control device and a motor control method according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a motor control device 80 according to the present invention. A motor control device 80 shown in FIG. 1 has a speed control unit 30 that outputs a voltage U between terminals for driving the motor 12 to the motor driver 16 and controls the speed of the motor 12. The motor driver 16 rotationally drives the motor 12 with the inter-terminal voltage U input from the speed control unit 30. The rotational driving force of the motor 12 is transmitted to the driving wheel 14 via a reduction gear (not shown), and the driving wheel 14 rotates. The rotation of the driving wheel 14 supports the traveling of the vehicle 10 and reduces the load on the person. In addition, the vehicle 10 here means all the vehicles which drive | work with human power, such as a wheelchair, a trolley | bogie, a rear car, a stroller, a shopping cart, a bicycle. The motor control device 80 and the motor control method according to the present invention are basically for assisting the travel of the vehicle 10 by human power to reduce the load on the person, and the vehicle 10 is traveled only by the motor 12. I don't assume that. The driving wheel 14 may be configured as a driving wheel 14 by providing a driving device on the wheel of the vehicle 10 itself, or an electric assist device having the driving wheel 14 may be installed in the vehicle 10.

  In addition, the motor control device 80 acquires a voltage U between terminals output from the speed control unit 30 and a current value I flowing down the motor 12, and calculates an angular speed ω of the driving wheel 14 of the vehicle 10; The disturbance observer unit 34 estimates the human power value Fxs acting on the vehicle 10 based on the angular velocity ω of the drive wheel 14 calculated by the speed observer unit 32 and the current value I, and the human power estimated by the disturbance observer unit 34. And an admittance control unit 36 that sets a target speed Vref of the vehicle 10 based on the value Fxs and feeds it back to the speed control unit 30.

  Here, an example of a method for obtaining the voltage U between the terminals and the current value I flowing down the motor 12 will be briefly described. First, the current value I of the motor 12 can be acquired as an analog signal from the current sensor of the motor driver 16 that drives the motor 12. At this time, it is preferable that the motor driver 16 and the motor control device 80 are insulated using, for example, an insulation amplifier, and a current value I is obtained by amplifying a signal that has passed through the insulation amplifier. Further, the terminal voltage U is obtained by dividing the voltage output from the speed controller 30 to the motor 12 via the motor driver 16 and then divided, and then the reference potential is unified and the output range is adjusted using an instrumentation amplifier. Further, since the voltage U between terminals is switched between positive and negative depending on the rotation direction of the motor 12, a predetermined bias voltage is applied by an instrumentation amplifier, for example, 2.5V to 5V for forward rotation and 0V to 2.5V for reverse rotation. As described above, it is preferable to acquire the voltage between positive and negative terminals by converting it into a positive terminal voltage U. The above corresponds to the VI acquisition step of the motor control method according to the present invention.

ここで、モータ１２の巻線抵抗Ｒ、減速ギアのギア比ｇｒ、逆起電力定数Ｋｅは、実測等により取得が可能な定数であるから、よって、モータ１２の端子間電圧Ｕとモータ１２の電流値Ｉとから駆動車輪１４の角速度ωは算出することができる。そして、速度オブザーバ部３２は予め設定されている巻線抵抗Ｒ、減速ギアのギア比ｇｒ、逆起電力定数Ｋｅと、取得した端子間電圧Ｕと電流値Ｉとから駆動車輪１４の角速度ωを算出して速度オブザーバ部３２に出力する。以上が本発明に係るモータ制御方法の角速度算出ステップに相当する。 Next, a method for calculating the angular velocity ω of the drive wheel 14 by the speed observer unit 32 will be described. First, the angular velocity ωm of the motor 12 is expressed as follows from the equation of the counter electromotive force Ue [V]. Here, Ke is a back electromotive force constant [Vs / rad].
Ue = Ke · ωm
Further, the inductance of the small motor 12 is small. If this inductance is ignored, the voltage U between the terminals of the motor 12 is calculated from the back electromotive force Ue, the winding resistance R [Ω] of the motor 12 and the current value I of the motor 12. It is expressed as
U = R · I + Ue
Therefore, the angular velocity ωm of the motor 12 is expressed as follows.
ωm = (U−R · I) / Ke
Then, assuming that the gear ratio of the reduction gear of the motor 12 is gr, the angular velocity ω of the drive wheel 14 is expressed as follows.
ω = ωm / gr
Therefore, when the inductance of the motor 12 is ignored, the angular velocity ω of the drive wheel 14 is expressed as follows.

Here, the winding resistance R of the motor 12, the gear ratio gr of the reduction gear, and the back electromotive force constant Ke are constants that can be obtained by actual measurement or the like. Therefore, the terminal voltage U of the motor 12 and the motor 12 From the current value I, the angular velocity ω of the drive wheel 14 can be calculated. The speed observer 32 calculates the angular speed ω of the driving wheel 14 from the preset winding resistance R, the gear ratio gr of the reduction gear, the counter electromotive force constant Ke, and the acquired terminal voltage U and current value I. Calculate and output to the speed observer unit 32. The above corresponds to the angular velocity calculation step of the motor control method according to the present invention.

よって、駆動車輪１４のトルクＴ_Ｌは次のように表される。

そして、力Ｆ_Ｌは、Ｆ_Ｌ＝（ｇｒ／ｒ）・Ｔ_Ｌ で表されるから、力Ｆ_Ｌは次のように表される。尚、ｇｒは前述の減速ギアのギア比であり、ｒはモータ１２の半径である。

また、路面との転がり摩擦抵抗Ｆｒは次のように表される。尚、ｃは車両１０の転がり摩擦定数であり、ｍは車両１０と積載物とを合わせた重量であり、ｇは重力加速度である。
Ｆｒ＝ｃ・ｍ・ｇ
また、車両１０に掛かる力Ｆは運動方程式によって次のように表される。尚、Ｄｗは車両１０の粘性抵抗係数である。

よって、人力Ｆｘは次のように表される。

Next, a method for estimating the human power Fx by the disturbance observer unit 34 will be described. First, the force F applied to the vehicle 10 in the plane is expressed as follows. Here, F _L is the assist force of the drive wheels 14, Fr is the rolling friction with the road surface.
F = Fx + F _L −Fr
Here, the torque Tm of the motor 12 is expressed as follows using the current value I. Kτ is a torque constant [NmA] of the motor 12.
Tm = Kτ · I
The torque Tm of the motor 12 is also expressed as follows. Here, _TL is the torque of the drive wheel 14, J [Kgm ² ] is the moment of inertia of the motor, and Dm is the viscous resistance coefficient [Nm · rad / s] of the motor. Ωm is the angular velocity of the motor 12 described above.

Therefore, the torque _TL of the drive wheel 14 is expressed as follows.

Then, the force _{F L,} since represented by F L = (gr / r) · T L, the force _{F L} is expressed as follows. In addition, gr is a gear ratio of the above-described reduction gear, and r is a radius of the motor 12.

The rolling friction resistance Fr with the road surface is expressed as follows. Note that c is a rolling friction constant of the vehicle 10, m is a weight of the vehicle 10 and a load, and g is a gravitational acceleration.
Fr = c · m · g
The force F applied to the vehicle 10 is expressed as follows by the equation of motion. Dw is a viscous resistance coefficient of the vehicle 10.

Therefore, human power Fx is expressed as follows.

  Here, the combined weight m of the vehicle 10 and the load, the radius r of the motor 12, the viscosity resistance coefficient Dw of the vehicle 10, the gear ratio gr of the reduction gear, the torque constant Kτ of the motor 12, the moment of inertia J of the motor, the motor The viscous resistance coefficient Dm is a constant that can be obtained by actual measurement or the like. Further, the angular velocity ωm of the motor 12 can be obtained from the angular velocity ω of the drive wheel 14 as described above.

  Further, the rolling friction constant c of the vehicle 10 largely depends on the friction constant of the driving wheel 14 and does not vary greatly depending on the road surface condition. Therefore, the rolling friction constant c can be fixed to the friction constant of the vehicle 10 in an average road surface state. Alternatively, a plurality of rolling friction constants c may be set in advance and the user may select and set each time. From the above, the variables in the above [Equation 6] are only the angular velocity ω of the driving wheel 14 (angular velocity ωm of the motor 12) and the current value I, and therefore the estimated value of the human power Fx is the angular velocity ω of the driving wheel 14 and the current. It can be calculated from the value I.

Further, as shown in the model diagram of FIG. 2, the force Fs applied to the vehicle 10 on the slope of the angle θ ° is expressed as follows. Here, F L _s is the assisting force of the drive wheel 14 in the slope, Frs is frictional resistance to the road surface slope.
Fs = Fxs + F _L s−Frs
Here, F _L s = F _L + m · g · sin θ,
Since Frs = c · m · g · cos θ, the human power Fxs on the slope is expressed by the following equation based on this and the above-mentioned equation [6].

  Since θ is 0 ° in the plane, cos θ = 1 and sin θ = 0, and the above [Expression 7] can be applied to the plane. Therefore, when θ is 0 °, Fxs = Fx. The angle θ may be automatically acquired by an angle sensor, a clinometer, or the like, or a plurality of angles θ may be recorded in advance and the user may select as appropriate. In addition, since the slope of a normal pavement in Japan is normally 5 ° or less, the angle θ may be fixed at 4 °, for example, and only up / down directions may be acquired or input.

  Thus, if the angle θ of the slope is obtained, the estimated value of the human force Fxs shown in the equation [7] can be calculated from the angular velocity ω and the current value I of the drive wheel 14 as described above. Then, the disturbance observer unit 34 outputs the estimated value of the human power Fxs calculated as described above to the admittance control unit 36. The above corresponds to the manpower estimation step of the motor control method according to the present invention.

  Next, a method for calculating the target speed Vref of the vehicle 10 by the admittance control unit 36 will be described. The motor control device 80 and the motor control method according to the present invention control the motor 12 so that the human power Fxs is kept substantially constant when the vehicle 10 enters a slope or a rough road and the load on the person changes. To do. Therefore, the admittance control unit 36 increases the target speed Vref and increases the inter-terminal voltage U in a scene where the human power Fxs increases on an uphill or the like. Thereby, the torque of the drive wheel 14 increases and the load on the person decreases. Further, in a scene where the load on the person decreases, the admittance control unit 36 decreases the target speed Vref and decreases the inter-terminal voltage U. Thereby, the torque of the drive wheel 14 is reduced and the load on the person is maintained substantially constant.

この式から、アドミッタンス制御部３６の伝達関数は、次の式で表される。尚、ｓはラブラス変換の複素数である。

そして、目標速度Ｖｒｅｆ（下記［数１０］におけるＶｒｅｆ（ｓ））は人力Ｆｘｓ（下記［数１０］におけるＦｘｓ（ｓ））により次の式で表される。

これにより、人力Ｆｘｓによって目標速度Ｖｒｅｆが設定される。以上が本発明に係るモータ制御方法の目標速度設定ステップに相当する。 Here, human power Fxs (t) (F (t) in the following [Equation 8]) is expressed by the following expression in the time domain. Note that M is a virtual mass, and D is a virtual damping coefficient. These virtual mass M and virtual damping coefficient D are parameters that determine the load on the person and the response speed and reaction speed of the motor control device 80, and are set in advance by the designer according to the weight, usage method, model, etc. of the vehicle 10. To do.

From this equation, the transfer function of the admittance control unit 36 is expressed by the following equation. Note that s is a complex number of the Lavras transform.

The target speed Vref (Vref (s) in the following [Equation 10]) is expressed by the following formula using the human power Fxs (Fxs (s) in the following [Equation 10]).

Thereby, the target speed Vref is set by the human power Fxs. The above corresponds to the target speed setting step of the motor control method according to the present invention.

このように、時定数τは仮想質量Ｍと仮想ダンピング係数Ｄで表され、時定数τが小さいほど定常状態（人への負荷が略一定に制御された状態）になるまでの時間が早まる。
また、定常状態のとき駆動車輪１４の速度はＶ＝Ｆ／Ｄ となる。これにより人の負荷感覚Ｆは次の式のようになる。
Ｆ＝Ｖ・Ｄ
この式から、定常状態においては仮想ダンピング係数Ｄによって人の負荷感覚を設定することが出来る。以上がアドミッタンス制御を用いた人力補助の原理である。 When the human power Fxs is a step-like input, the time response of the target speed Vref is expressed by the following equation. Here, τ is a time constant, and F is a human load sense.

As described above, the time constant τ is represented by the virtual mass M and the virtual damping coefficient D. The smaller the time constant τ, the faster the time until a steady state (a state in which the load on the person is controlled to be substantially constant) is obtained.
In the steady state, the speed of the drive wheel 14 is V = F / D. As a result, the human load sensation F becomes as follows.
F = V · D
From this equation, the human load sensation can be set by the virtual damping coefficient D in the steady state. The above is the principle of human power assistance using admittance control.

  Then, the target speed Vref set by the admittance control unit 36 is output to the speed control unit 30. Further, the speed observer unit 32 calculates the speed V (= ω · r) of the driving wheel 14 and outputs it to the speed control unit 30. The speed control unit 30 appropriately adjusts the target speed Vref and approaches the target speed Vref by the known P (Proportional), I (Integral), and D (Differential). The terminal voltage U is output. Thereby, the motor 12 is driven so as to approach the target speed Vref. The above corresponds to the control steps of the motor control method according to the present invention. FIG. 3 shows a block diagram of the motor control device 80 according to the present invention described above on a flat ground.

  By controlling the motor 12 by the motor control device 80, the torque of the driving wheel 14 gradually increases and decreases so that the human power Fxs becomes substantially constant, and finally the load on the person is in a steady state (for example, traveling on a flat ground). Time).

  Note that the virtual damping coefficient D set by the admittance control unit 36 may be configured to gradually change to an optimum value by a learning function. For example, the virtual damping coefficient D (n) is composed of the difference E (n) between the target load Fxd and the human power Fxs (n) and the learning gain G, and the learning gain G is set so that the difference E (n) becomes small. Change sequentially. According to this configuration, as the vehicle 10 travels, the virtual damping coefficient D is gradually optimized, and a smooth assist operation with respect to load fluctuations can be performed. The above corresponds to the learning step of the motor control method according to the present invention.

  In the motor control device 80 and the motor control method according to the present invention, the filter unit 38 (low-pass filter) is provided between the disturbance observer unit 34 and the admittance control unit 36, and the human power Fxs output from the disturbance observer unit 34 is rapidly increased. Such fluctuation components (high-frequency components) may be removed. Here, for example, when the vehicle 10 collides with a step or the like, the angular velocity ω changes suddenly, and accordingly, Fxs becomes instantaneously excessive. In such a case, there is a risk that the target speed Vref becomes excessive and the vehicle 10 runs away. However, by providing the filter unit 38 between the disturbance observer unit 34 and the admittance control unit 36, the instantaneous fluctuation of Fxs due to such a sudden event can be eliminated. The above corresponds to the filter step of the motor control method according to the present invention.

  As described above, the motor control device 80 and the motor control method according to the present invention calculate the value Fxs of the human power acting on the vehicle 10 based on the voltage U between the terminals of the motor 12 and the current value I flowing down the motor 12. . Then, the motor 12 is controlled based on the human power Fxs. For this reason, an expensive sensor for acquiring drive system information such as a torque sensor becomes unnecessary, and the motor control device 80 used in the electric assist device can be configured at a very low cost. As a result, an electric assist device that automatically controls the rotational force of the motor according to the load can be provided at a very low cost.

  The configuration of the motor control device 80 and the motor control method shown in this example is an example, and the configuration, mechanism, circuit, and the like of each part are not limited to the above examples, and do not depart from the gist of the present invention. It is possible to change and implement.

10 Vehicle
12 Motor
14 Drive wheels
30 Speed controller
32 Speed observer
34 Disturbance Observer
36 Admittance Control Unit
38 Filter section
80 Motor controller

Claims (7)

A motor control device for driving wheels that assists in driving a vehicle powered by human power,
A speed controller for controlling the voltage between the terminals of the motor of the drive wheel according to the target speed of the vehicle;
A speed observer unit for obtaining an inter-terminal voltage output by the speed control unit and a current value flowing down the motor and calculating an angular velocity of the driving wheel;
A disturbance observer unit for estimating a value of a human force acting on the vehicle based on the angular velocity calculated by the speed observer unit and the current value;
An admittance control unit configured to set a target speed of the vehicle based on a human power value estimated by the disturbance observer unit and feed back to the speed control unit. The speed observer unit is based on the following equation based on the voltage U between terminals, the current value I, the previously obtained gear ratio gr of the reduction gear of the motor, the winding resistance R of the motor, and the counter electromotive force constant Ke of the motor. To calculate the angular velocity ω of the drive wheel,

The disturbance observer unit includes the angular velocity ω, the terminal voltage U, the motor radius r, the vehicle viscosity resistance coefficient Dw, the gear ratio gr of the reduction gear, the torque constant Kτ of the motor, and the moment of inertia of the motor. Based on the following equation, J, the viscous resistance coefficient Dm of the motor, the gravitational acceleration g, the input or preset weight m of the vehicle and the load, the rolling friction constant c of the vehicle, and the angle θ of the slope. To estimate the human power value Fxs,

The admittance control unit is based on the following equation from the human force value Fxs estimated by the disturbance observer unit, the virtual mass M that is arbitrarily set and related to the load on the person and the response speed to the driving wheel, and the virtual damping coefficient D The motor control device according to claim 1, wherein a target speed Vref of the vehicle is set.

The motor control device according to claim 2, further comprising a filter unit that removes a sudden fluctuation component of the human power value Fxs output by the disturbance observer unit. A motor control method for driving wheels that assists in driving a vehicle powered by human power,
A VI acquisition step of acquiring a voltage between terminals of the motor of the driving wheel and a current value flowing down the motor;
An angular velocity calculating step of calculating an angular velocity of the driving wheel based on the inter-terminal voltage and the current value acquired in the VI acquiring step;
A human power estimating step for estimating a value of human power acting on the vehicle based on the angular velocity calculated in the angular velocity calculating step and the current value;
A target speed setting step for setting the target speed of the vehicle based on the value of the human power estimated in the human power estimation step;
And a control step of speed-controlling the voltage between the terminals of the motor based on the target speed set in the target speed setting step. The angular velocity calculation step is based on the following equation based on the terminal voltage U and the current value I, the previously obtained gear ratio gr of the reduction gear of the motor, the winding resistance R of the motor, and the counter electromotive force constant Ke of the motor. To calculate the angular velocity ω of the drive wheel,

The human power estimation step includes the angular velocity ω, the terminal voltage U, the motor radius r, the vehicle viscous resistance coefficient Dw, the gear ratio gr of the reduction gear, the torque constant Kτ of the motor, and the moment of inertia of the motor. Based on the following equation, J, the viscous resistance coefficient Dm of the motor, the gravitational acceleration g, the input or preset weight m of the vehicle and the load, the rolling friction constant c of the vehicle, and the angle θ of the slope. To estimate the human power value Fxs,

The target speed setting step is expressed by the following equation from the human power value Fxs estimated by the human power estimation step, the virtual mass M that is arbitrarily set and related to the load on the person and the response speed to the driving wheel, and the virtual damping coefficient D. 5. The motor control method according to claim 4, wherein a target speed Vref of the vehicle is set based on the motor speed.

6. The motor control method according to claim 5, further comprising a filter step for removing a sudden fluctuation component of the human power value Fxs obtained in the human power estimation step. The virtual damping coefficient D is composed of the difference E (n) between the human power value Fxs (n) and the target load Fxd that are sequentially input and the learning gain, and the learning gain is sequentially set so that the difference E (n) becomes small. The motor control method according to claim 5, further comprising a learning step of changing and optimizing the virtual damping coefficient D.

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