JPH1099378A - Controller for motor-driven vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase driving force to a motor-driven vehicle without increasing the burden of an operator and to improve operability. SOLUTION: Operating force for a person to move the vehicle forward is detected by operating force detecting parts 20R and 20L, and controllers 12R and 12L of a motor-driven wheelchair are provided with control parts 18R and 18L for generating the driving force for compensating this detected operating force at motors 10R and 10L when this operating force reaches a set value. The control parts 18R and 18L calculate the change amount of driving force by subtracting the set value from the operating force. By adding this change amount to current driving force, new driving force is generated at the motors 10R and 10L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a control device for an electric vehicle such as an electric wheelchair.

[0002]

2. Description of the Related Art An electric vehicle, such as a wheelchair, has a pair of drive wheels, each of which is driven by a motor. A control device is provided to control these motors.

An example of a control device for an electric wheelchair is disclosed in Japanese Patent Laid-Open No.
No. 75219 and JP-A-8-47114. The electric wheelchair is provided with an operation force detection unit that detects an operation force applied to the electric wheelchair by an operator of the electric wheelchair and generates an operation force signal in order to propel the electric wheelchair. An operating force signal is provided to the controller. The control device controls the motor such that the motor generates a driving force proportional to the operation force signal.

[0004]

However, in this control device, as the operating force increases, the driving force generated by the motor also increases in proportion to the operating force. Therefore, when the traveling load increases, for example, when the electric wheelchair needs to travel on an uphill from a state where the electric wheelchair is traveling on a flat road, and when the driving force of the motor needs to be increased. In addition, it is necessary to increase the operating force of the electric wheelchair. However, when the operator of the electric wheelchair is a weak person, the burden on the operator increases.

In this control device, when the operating force changes, the change immediately occurs as a change in the motor driving force. Therefore, for example, when the electric wheelchair is rapidly accelerated due to an increase in the operating force, the operator cannot follow the acceleration and decreases the operating force. In some cases, an operation force in a direction opposite to the traveling direction is detected by the operation force detection unit. As a result, the motor driving force decreases rapidly or is output in the direction opposite to the traveling direction. This change in the motor driving force causes the operator to increase the operating force. As a result, again, the electric wheelchair is rapidly accelerated. The electric wheelchair repeatedly accelerates, and the speed of the electric wheelchair becomes unstable. Therefore, in order to run the electric wheelchair at a stable speed, it is necessary to master the operation of the electric wheelchair, and the operability of the electric wheelchair is poor.

In the control device disclosed in JP-A-8-47114, the direction and magnitude of the driving force are determined in accordance with the direction and magnitude of the operating force. When the driving force is output by the motor, if the direction of the operating force is changed to the reverse direction, the motor will suddenly output the driving force in the reverse direction, causing a large change in the behavior of the electric wheelchair and operability. Deteriorate. Further, a current flowing in the motor in a direction opposite to that of the conventional motor suddenly flows, so that the load on the motor is large.

An object of the present invention is to provide a control device capable of increasing the driving force on an electric vehicle without increasing the burden on the operator. Also, the present invention
Even if the operating force on the electric vehicle fluctuates, the driving force on the electric vehicle can be changed smoothly, and as a result, the operability can be improved. It is an object to provide a control device. Still another object of the present invention is to provide a control unit that does not abruptly change the direction of the current flowing through the drive unit of the electric vehicle even when the direction of the operation force is changed.

[0008]

According to the first aspect of the present invention,
When the operating force when a person propells the vehicle reaches the set value,
In a control device for an electric vehicle provided with a control unit for generating a driving force for compensating for the operating force in the driving unit, the control unit subtracts the set value from the operating force to thereby reduce the driving force. Is calculated, and a new driving force is calculated by adding the amount of change to the driving force.

According to the first aspect of the invention, the amount of change in the driving force is a value obtained by subtracting the set value from the operating force. Therefore, even if the operating force is not changed, the new driving force increases by more than the current driving force by the value obtained by subtracting the set value from the operating force, so that the running load increases during the running of the electric vehicle. However, it is possible to cope with an increase in the running load without increasing the operating force. Further, by changing the driving force by increasing the operating force to be greater than the set value, the operating force is reduced to the set value and the operating force is maintained at the set value. Driven by force. Therefore, even when the electric vehicle is propelled with a constant driving force, it is only necessary to apply an operation force equal to the set value.

According to a second aspect of the present invention, in the first aspect of the present invention, the control unit adds an arbitrary coefficient, for example, a coefficient larger than 0 and smaller than 1 to a value obtained by subtracting the set value from the operation force. , The amount of change in the driving force that monotonically increases is calculated, and a new driving force is calculated by adding the amount of change to the driving force.

According to the second aspect of the present invention, a value obtained by subtracting the set value from the operating force is multiplied by an arbitrary coefficient, for example, a coefficient larger than 0 and smaller than 1 to obtain a change amount of the driving force. I have. Therefore, the amount of change in the driving force is always smaller than the amount of change in the driving force obtained by subtracting the set value from the operating force. Therefore, even if the operating force changes,
The driving force changes more slowly than the operating force,
That is, since the response of the driving force can be moderated, the operation of the electric vehicle can be easily performed, and the operability can be improved.

According to a third aspect of the present invention, in the control device similar to the first aspect of the present invention, the control unit sets an arbitrary number of thresholds, and a plurality of control areas defined by the thresholds. And the value obtained by subtracting the set value from the operating force is multiplied by an arbitrary coefficient determined for each control area, for example, a coefficient greater than 0 and smaller than 1 to obtain a monotonically increasing change in the driving force. A new driving force is calculated by calculating the amount and adding the amount of change to the driving force. The threshold value can be set for the operating force, or can be set for the amount of change in the driving force obtained by subtracting the set value from the operating force.

According to the third aspect of the invention, the operability can be improved similarly to the second aspect of the invention. In particular, the responsiveness of the driving force can be arbitrarily adjusted in accordance with the amount of change with respect to the set value of the operation force or the amount of change in the operation force. For example, when the amount of change with respect to the set value of the operating force is large, the amount of change in the driving force is increased, or conversely, when the amount of change with respect to the set value of the operational force is small, the amount of change in the drive force is reduced. And conversely, it can be increased, and the responsiveness of the driving force can be adjusted to a state according to the preference of the operator.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the coefficient of the control area including the set value is set to be smaller than the coefficient of the control area not including the set value. .

According to the fourth aspect of the present invention, since the coefficient of the control region including the set value inside is smaller than the coefficient of the control region not including the set value inside, the operating force fluctuates near the set value. Even so, the response of the driving force can be slowed. Therefore, the behavior of the electric vehicle can be stabilized without the electric vehicle rapidly accelerating or decelerating, and the operability of the electric vehicle can be improved. Also, in order to drive the two drive wheels of the electric vehicle independently,
Even when two operating force detectors are provided corresponding to the two drive wheels, respectively, even if the two operating force detectors detect an unbalanced operating force near the set value, the electric vehicle moves straight. Nature can be secured.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the coefficient of the control area including the set value is:
It is almost zero.

According to the fifth aspect of the present invention, even if the operating force fluctuates near the set value, the driving force hardly fluctuates, so that the behavior of the electric vehicle can be stabilized more than the fourth aspect of the present invention. Can be. Further, even when two operation force detection units are provided to respectively correspond to the two drive wheels to independently drive the two drive wheels of the electric vehicle, the two operation force detection units are used. Even if the detected operating force is a value near the set value and differs to some extent, it is possible to reliably secure the straightness of the electric vehicle.

According to a sixth aspect of the present invention, in the third aspect of the present invention, the control area is formed in three or more sections, and the coefficient of the control area including the set value and the control element farthest from the set value. The coefficient of the area is smaller than the coefficients of the other control areas.

According to the sixth aspect of the present invention, since the coefficients of the control area including the set value and the control area other than the control area farthest from the set value are larger than the coefficient of the control area including the set value, the control area is promptly increased. A state in which a desired driving force can be obtained, and thereafter, if the operating force is maintained at a set value, the electric vehicle can be propelled with a substantially desired driving force.
Therefore, the time during which the operating force is out of the set value can be reduced. Further, since the coefficient of the farthest control region is small, even if the operating force fluctuates greatly, the electric vehicle is prevented from being rapidly accelerated or decelerated, and the operability of the electric vehicle can be improved.

According to a seventh aspect of the present invention, in the electric vehicle control device similar to the first aspect of the present invention, the control unit multiplies a value obtained by subtracting a set value from the operation force by an arbitrary coefficient. A new driving force is calculated by calculating a change amount of the driving force obtained as a monotonically increasing portion of an n-order function where n is 2 or more, and adding the change amount to the driving force.

According to the seventh aspect of the invention, the amount of change in the driving force is obtained as a monotonically increasing function of two or more n-th order functions. Assuming that the operating force is Fin, the set value is Fs, and the coefficient is K, the amount of change in the driving force is, for example, K * (Fin−Fs)
It becomes ² . Therefore, when the operating force is near the set value, the amount of change in the driving force is small, that is, the response of the driving force is suppressed, and the behavior of the electric vehicle can be stabilized. As the distance increases, the responsiveness of the driving force can be increased, so that the desired driving force can be generated quickly, and thereafter, by maintaining the operating force at the set value, almost the desired driving force can be obtained. Can be maintained. Therefore, the time during which the operating force is equal to or greater than the set value can be reduced.

According to the invention described in claim 8, when the operating force when a person propells the vehicle reaches a set value, a driving force of a predetermined direction and magnitude for compensating the operating force is generated in the driving unit. In the control device for an electric vehicle provided with a control unit for causing the control unit to calculate a change amount of the driving force by subtracting the set value from the operation force, the control unit calculates the change amount as the driving force. By taking this into account, a new driving force in a predetermined direction and magnitude is calculated.

According to the present invention, the amount of change in the driving force is a value obtained by subtracting the set value from the operating force. Therefore, even if the operating force is not changed, the new driving force increases in a predetermined direction from the current driving force by a value obtained by subtracting the set value from the operating force. Even if the running load increases, it is possible to cope with the increase in the running load without increasing the operating force. Further, by changing the driving force in a predetermined direction by making the operating force larger than the set value, the operating force is reduced to the set value, and the operating force is maintained at the set value, the electric vehicle has a certain It is driven in a predetermined direction by a certain driving force. Therefore, even when propelling the electric vehicle in a predetermined direction with a constant driving force,
It is only necessary to apply an operating force equal to the set value.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, the control unit detects the direction of the operating force based on a determination result that the driving unit does not generate a driving force. The direction of the driving force is determined according to the direction of the operating force.

According to the ninth aspect of the present invention, the direction of the driving force is determined according to the direction of the operating force, but the direction of the driving force is determined by the driving unit not generating the driving force. When done. Therefore, for example, when an operating force is applied in a state where the driving unit does not generate a driving force and the electric vehicle is stopped, the driving direction of the electric vehicle becomes the direction of the applied operating force. Also, if the driving unit is generating driving force, even if an operating force in the opposite direction to the operating force applied so far is applied, the amount of change in the driving force will be a negative value, and the driving force will only decrease. Thus, the direction of the driving force remains determined according to the direction of the operating force. When no driving force is generated as a result of the decrease in driving force, a new driving force direction is determined according to the direction of the operation force detected at that time. Therefore, even if the direction of the operating force is reversed, as long as the driving unit is generating the driving force, the direction of the driving force generated by the driving unit does not suddenly reverse, and the behavior of the electric vehicle is reduced. It does not become unstable.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, when the new driving force direction is different from the determined driving force direction, the control unit reduces the driving force. It is set to zero once.

According to the tenth aspect of the present invention, for example, when an operating force in a direction opposite to the operating force applied so far is applied in a state where the driving unit is generating the driving force, the amount of change in the driving force is reduced. It becomes a negative value, the driving force gradually decreases, and eventually the driving force becomes a negative value. In this state, a driving force in a different direction will be generated, so that once the driving force is set to 0 and the driving of the electric vehicle is stopped, it is possible to prevent the driving force direction from suddenly reversing. At this time, the direction of the applied operating force is newly detected, and the direction in which the driving unit is driven is determined. Therefore, the direction of the driving force of the electric vehicle does not suddenly reverse, and the behavior of the electric vehicle does not become unstable.

According to an eleventh aspect of the present invention, a direction and a magnitude of an operation force applied to a vehicle when a person propels the vehicle are detected, and a predetermined direction and a magnitude are determined based on the detected operation force. In the control device of the electric vehicle provided with a control unit that calculates the driving force of the driving unit, the control unit based on a determination result that the driving unit does not generate the driving force, When the direction of the driving force is determined according to the direction of the operating force, and the direction of the driving force newly calculated based on the operating force is different from the determined direction of the driving force, The driving force is temporarily reduced to zero.

According to the eleventh aspect, once the direction of the driving force is determined when no driving force is generated, even if the direction of the operating force is reversed, the driving force is determined. Until no more occurs, the current direction of the driving force is maintained. Therefore, even if the direction of the operating force is reversed, the driving direction of the electric vehicle does not suddenly reverse, the behavior of the electric vehicle is stabilized, and the operability is improved. When the driving force is not generated, the direction of the driving force is newly determined based on the direction of the operating force at that time. When the direction of the driving force is a specific direction, as a result of changing the direction of the operating force, the direction of the calculated driving force may be opposite to the direction of the driving force actually generated by the driving unit. is there. In such a case, the actual driving force is temporarily set to zero. Thereby, the direction of the driving force is newly determined based on the direction of the operating force at that time, and the magnitude of the driving force is determined based on the operating force at that time.
The driving direction of the electric vehicle does not suddenly reverse, the behavior of the electric vehicle is stabilized, and the operability is improved. Further, the direction of the current flowing through the drive unit does not suddenly reverse, and the load on the drive unit is reduced.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, the present invention is applied to an electric vehicle, for example, an electric wheelchair 1. The electric wheelchair 1 has a pipe frame-shaped frame 2 as shown in FIG. When the frame 2 is viewed from the front, a cloth seat 4 on which the occupant sits is stretched in a central portion thereof. Drive wheels 6R and 6L are provided on the rear side on both sides of the frame 2. Auxiliary wheels 8R, 8L are provided on both front sides of the frame 2.

The driving wheels 6R and 6L are, as shown in FIG.
A drive unit for driving the drive wheels 6R and 6L, for example, electric motors 10R and 10L is built therein. In addition, the motors 10R, 1R are provided in the drive wheels 6R, 6L.
Control devices 12R and 12L for controlling 0L are also provided. Batteries 14R and 14L for supplying power to these control devices 12R and 12L are also provided in the drive wheels 6R and 6L.

The control devices 12R, 12L include batteries 14R,
The motor drive unit 16R, which controls the voltage of 14L and supplies it to the motors 10R and 10L by, for example, PWM control
6L. In addition, the control devices 12R and 12L
PWM that instructs the motor drive units 16R and 16L how to control the motors 10R and 10L by PWM.
Control units 18L and 18R for supplying signals are provided. The control units 18R and 18L can be configured by, for example, a microprocessor. This control unit 18R, 1
An operation force detection signal is supplied to 8L from the operation force detection units 20R and 20L. The control units 18R and 18L generate command driving forces FoutR and FoutL, as described later, using the operation force detection signals and the like, and convert them into PWM signals.

As shown in FIG. 2, the operating force detecting units 20R and 20L are provided on two handles 22R and 22L projecting rearward from the back of the frame 2 in parallel with each other so as to be able to advance and retreat. The operation force detection units 20R and 20L independently detect the operation force applied to the handles 22R and 22L by the caregiver, and generate an operation force detection signal. The operation force detection units 20R and 20L include, for example, a potentiometer inside, and the resistance value of the potentiometer changes according to the operation force applied to the operation force detection units 20R and 20L. Note that the operation force detection units 20R and 20L may include a bridge circuit including a strain gauge instead of the potentiometer.

The operation force detection signals from the operation force detection units 20R and 20L are 0 when no operation force is applied, for example, as shown in FIG. When an operation force in the direction of moving the electric wheelchair 1 forward is applied to the operation force detection units 20R and 20L, the operation force detection signal is a positive signal having a value proportional to the operation force. When the operation force in the direction of retreating the electric wheelchair 1 is applied to the operation force detection units 20R and 20L, the operation force detection signal is a negative signal having a value proportional to the force. The operation force detection signal from the operation force detection unit 20R is
It is supplied to the control unit 18R. The operation force detection signal from the operation force detection unit 20L is supplied to the control unit 18L. The control units 18R and 18L control the corresponding drive wheels 6R and 6L according to the input operation force detection signal.

The operating force detecting section is adapted to independently detect the operating force applied by the occupant to the hand rims 24R, 24L provided on the drive wheels 6R, 6L, in addition to those shown. , Hand rim 24
R and 24L can also be used.

The state in which the control units 18R and 18L control the corresponding drive wheels 6R and 6L will be described below.
Since the control performed by both control units 18R and 18L is the same, only the control of the control unit 18R will be described.

The control section 18R samples the operation force detection signal from the operation force detection section 20R at a predetermined period, for example, every 1/100 second, and outputs a digital operation force signal Fin.
Convert to R Next, in the control unit 18R, the command driving force F
When outR is zero, that is, when the electric wheelchair is not driven by the driving force of the motor 10R, the direction of the digital operation force signal FinR is determined, and it is determined whether the motor 10R is to be rotated forward or backward. Command driving force FoutR
Is not zero, the motor 10R is currently rotating in the forward or reverse direction, and therefore maintains its rotation direction. next,
In the control unit 18R, FinR is set to a predetermined set value Fs.
Alternatively, when -FoutR is 0, a PWM signal is sent to the motor drive unit 16R so that the motor drive unit 16R does not drive the motor 10R. Therefore, during this time, the electric wheelchair 1 is propelled only by the operation force.

When the digital operation force signal FinR exceeds the set value Fs or -Fs, the controller 18R calculates the difference between FinR and the set value Fs when the digital operation force signal FinR is positive, and calculates the digital operation force. When the signal FinR is negative, a difference between -FinR and the set value Fs is obtained.
This difference is set as a driving force change amount dFa, and a value obtained by multiplying the difference by a coefficient K is added to the current driving force Fa (t-1).
A new driving force Fa (t) is obtained.

For example, if the set value Fs is 3 and FinR is 4
Is maintained, the amount of change in the driving force becomes 1 continuously, and when the coefficient K is 1, the driving force becomes 1,
Even if the operating force is not changed to 2, 3,. Therefore, even when the running load increases, it is not necessary to increase the operating force.

For example, consider a case where the set value Fs is 3 and the FinR changes to 4, 6, 7, 8, 7, 5, 4, 2, 1, 1, and 3. The change amount of the driving force is 1, 3, 4, 5,
4, 2, 1, -1, -2, 0, and 1, 4, 8, 1
The driving force changes to 3, 17, 19, 20, 19, 17, and 17, and if the operating force is thereafter maintained at 3, which is equal to the set value Fs, the driving force is maintained at 17. Therefore, after operating the operation force detection unit 20R, the operation force to the operation force detection unit 20R is maintained at the set value so that the desired driving force is finally obtained in a state where the operation force matches the set value. Then, the desired driving force can be maintained. The relationship between the change amount dFa of the driving force and the digital operation force signal FinR after FinR becomes equal to or larger than Fs is shown by a solid line in FIG.

In the above example, the value obtained by multiplying the difference between FinR and Fs by a coefficient 1 is used as the driving force variation dFa. However, the value of the coefficient K can be arbitrarily changed. For example, a value obtained by multiplying a coefficient larger than 0 and around 1 (including a case where it is smaller than 1 and a case where it is larger) is set as a driving force change amount dFa. You can also. The relationship between the change amount dFa of the driving force and the digital operation force signal FinR when the coefficient K = 0.5 is shown by a dashed line in FIG. By multiplying (Fin-Fs) by the coefficient K having a value smaller than 1 and larger than 0, the response of the driving force can be moderated. For example, in the above example, when the coefficient K = 1, the driving force is 1, 4, 8, 13, 17, 19, 20,
19, 17, and 17, but when the coefficient K = 0.5, the driving force is 0.5, 2, 4, 6.5, 8.5, 9.5.
5, 10, 9.5, 8.5, 8.5, and the amount of change in the driving force is の of the case where the coefficient K = 1. As described above, the responsiveness of the driving force is reduced, and the operating force is stabilized.

The straight line shown in FIG. 4 shows the relationship between the digital operation force signal FinR and the driving force change amount dFa when the value is positive. When the digital operation force signal FinR is negative, -FinR obtained by inverting the value of FinR can be used. Again,
DFa is determined in the same manner as described above. Note that a large number of coefficients K (for example, values larger than 0 and near 1) may be prepared in advance, and an arbitrary coefficient may be selected from these coefficients according to the preference of the caregiver.

In the above example, the coefficient K (1 or 0.5) for obtaining dFa is a constant value regardless of the value of the digital operation force signal. However, it is also possible to change the value of the coefficient K according to the value of the digital operation force signal as shown in FIGS. 5, 7 to 9, for example. Of course, even in these cases, the new driving force Fa (t) is equal to Fa (t−
1) It is determined by + dFa.

In FIG. 5, two threshold values Fs-Fh and Fs + Fh are set on both sides of the set value Fs (0 <Fs).
Fh <Fs). Control region C1 smaller than threshold value Fs-Fh and control region C larger than threshold value Fs + Fh
In the case of 2, for example, 1 is used as the coefficient K. Digital operation force signal is greater than or equal to threshold value Fs-Fh, Fs + Fh
In the following control area C3, for example, 0.5 is used as the coefficient K. For example, when Fs is set to 2.5 kg, 0.5 kg can be used as Fh.

Since the coefficient K is small near the set value Fs, even if the digital operating force signal fluctuates near the set value Fs, the response of the driving force can be slowed down. 1 can be stabilized.
Further, like the electric wheelchair 1, the driving wheel 6R is controlled according to the operating force detected by the operating force detecting unit 20R, and the driving wheel 6L is controlled according to the operating force detected by the operating force detecting unit 20L. In this case, even if the operation force detected by the operation force detection units 20R and 20L is unbalanced, the electric wheelchair 1 can move straight.

This will be described with reference to FIG. FIG. 5 shows a curve a indicating a change in the operating force over time in FIG. 4 and a curve b indicating a change in the motor driving force over time in FIG. A change in the operating force over time is indicated by a curve c, and a change in the motor driving force over time in FIG. 5 is indicated by a curve d. However, in the section T1, the electric wheelchair 1 travels with a certain traveling load L1, and in the section T2, the electric wheelchair 1 travels with a traveling load L2 larger than the traveling load L1.
In section T3, traveling load L3 smaller than traveling load L1.
In this state, the electric wheelchair 1 is running.

For example, in the section T1, in the case of FIG. 4, the driving force of the motor 10R increases as the operator increases the operation force. Then, the driving force, which is larger than the total driving force that the operator considers necessary at that time,
When the operating force and the driving force of the motor 10R are generated, the operator decreases the operating force. Accordingly, the driving force of the motor 10R continues to increase, but the amount of change is reduced. When the operating force becomes smaller than the set value Fs, the driving force of the motor 10R decreases. Operating force and motor 10
When the total driving force in which the driving force of R is generated is smaller than the driving force required by the operator at that time,
The operator increases the operation force. Note that the absolute value of the deviation from the set value Fs of the operating force at this time is smaller than the absolute value of the deviation from the operating force Fs when the reduction of the operating force is first started.

As the operating force decreases, the driving force of the motor 10R continues to decrease, but the change amount decreases. When the operation force becomes larger than the set value Fs, the motor 1
The driving force of 0R starts to increase. When the total driving force generated by the operating force and the driving force of the motor 10R becomes larger than the driving force required by the operator at that time, the operator decreases the operating force. The set value Fs of the operating force at this time
Is smaller than the absolute value of the deviation from the set value of the operation force when the increase of the operation force is started.
That is, as the speed of the electric wheelchair 1 based on the total driving force of the operating force and the driving force of the motor 10R gradually approaches the desired speed, the operating force also gradually approaches the set value. In the same manner as described above, the speed of the electric wheelchair becomes a desired speed, and the operation force becomes the set value Fs.

In the case of FIG. 4, the coefficient K is always 1.
In the case of FIG. 5, the operating force is determined by the threshold values Fs + Fh and Fs−
When in the range of Fh, the coefficient K is 0.5, and outside this range, the coefficient K is 1.

Therefore, in the case of FIG.
Until s + Fh, the coefficient K is 0.5, so that the response of the driving force of the motor 10R is gentler than in the case of FIG. When the operating force exceeds the threshold value Fs + Fs, the coefficient K becomes 1, and the response of the driving force of the motor 10R becomes faster than when the coefficient K is 0.5. However, since the driving force until the operation force exceeds the threshold value Fs + Fh is smaller than the case where the coefficient K is 1, the operation force when the driving force required by the operator becomes smaller than that in FIG. growing. When the operating force is reduced, the operating force becomes the threshold value Fs +
Since the coefficient K is 1 while it is larger than Fh, the motor 1
The amount of change in the driving force of 0R is the same as in the case of FIG.

However, when the operating force is smaller than the threshold value Fs + Fh, the coefficient K becomes 0.5, and the motor 10R
Is smaller than that in the case of FIG. Then, when the total driving force by the operating force and the driving force of the motor 10R becomes smaller than the driving force required at that time, the operating force is increased. Accordingly, the driving force of the motor 10R also increases. However, the coefficient K is 0.5
Therefore, the amount of change in the increase in the driving force is smaller than that in the case of FIG. Accordingly, the total driving force also gradually increases, and with the operating force slightly exceeding the set value Fs, the total driving force by the operating force and the driving force of the motor 10R slightly exceeds the driving force required at that time. . Hereinafter, by setting the operating force to the set value Fs, the electric wheelchair 1 runs at a speed required by the operator.

In section T2, the running load is larger than in section T1, so that the operating force is increased. However, the operating force does not exceed the threshold value Fs + Fh.
Also in this case, the coefficient K is 1 in the case of FIG. 4, whereas the coefficient K is 0.5 in the case of FIG. Therefore, depending on the value of the coefficient K, the response of the motor 10R is gentler in FIG. 5 and the operability is improved.

In the section T3, when the running load becomes smaller than the section T1, the operating force is temporarily set to the threshold value Fs-F.
h. Therefore, the change in the operating force and the change in the driving force of the motor 10R are opposite to those in the section T1.

In FIG. 6, t11, t21, t
31 is the settling time in the case of FIG. 5, t21, t2
2, t23 represents the settling time in the case of FIG. The settling time is the time from when the operating force is changed from the start point of each section T1, T2, T3 until the electric wheelchair 1 reaches a desired speed and the operating force returns to the set value Fs. As is clear from FIG. 6, the settling time is shorter in the case of FIG.

In FIG. 7, the control areas C1 to C3 are shown in FIG.
Is set in the same way as However, the control area C
At 1 and C2, the coefficient K is set to 1, for example, and the control area C3
, The coefficient K is set to 0. As described above, when the coefficient K is set to 0 in the control region C3, the driving force does not change even if the digital operating force signal fluctuates near the set value Fs.
Therefore, the operation of the electric wheelchair 1 can be stabilized,
Operability is further improved. In addition, the operation force detection units 20R, 2R,
Even if the operation force detected at 0 L is unbalanced, the electric wheelchair 1 can be made to move straight ahead. Note that the coefficient K of the control area C3 does not necessarily need to be 0,
A value close to this, for example, 0.1 or 0.2 can also be used.

In FIG. 8, two values are set on both sides of the set value Fs.
Thresholds Fs-Fh1, Fs-Fh2 and Fs + Fh
1, Fs + Fh2 (Fh1 <Fh
2). Control region C4 smaller than threshold value Fs-Fh2
And the control region C5 larger than the threshold value Fs + Fh2, for example, 0.5 is used as the coefficient K. A control region C6 which is equal to or larger than the threshold value Fs-Fh2 and smaller than Fs-Fh1,
For example, 1.2 is used as the coefficient K in the control region C7 that is equal to or less than s + Fh2. Threshold value Fs-Fh
In the control region C8 of 1 or more and Fs + Fh1 or less, for example, 0.5 is used as the coefficient K.

In the control areas C6 and C7, other control areas C
Since the coefficient K is set to be larger than 4, C5, and C8, it is possible to shorten the time during which the digital operation force signal is out of the set value Fs. Further, in the control areas C4 and C5 farthest from the set value Fs, the coefficient K is set to be small. Therefore, even when the digital operating force signal greatly changes to enter these control areas, the electric wheelchair 1 is not affected. Can be prevented from being rapidly accelerated or decelerated.
In the control region C8 including the set value Fs, the coefficient K is set small, so that the response of the driving force is slowed down even if the digital operating force signal fluctuates near the set value Fs, as in the case of FIG. Therefore, the operation of the electric wheelchair 1 can be stabilized, and the operability can be improved. Also,
It is possible to improve the straightness of the electric wheelchair 1 when the digital operation force signal is near the set value Fs.

The coefficient K for the control areas C6 and C7 and the coefficient K for the control areas C4, C5 and C8 are merely examples, and may be other values. Further, each of the control areas C4 to C8
The values of the respective coefficients K may all be different. Also,
Although the number of control areas is five from C4 to C8, any number can be used as long as the number is three or more.

In FIG. 9, the coefficient K is an absolute value of a value obtained by multiplying a difference between the digital operation force signal FinR and the set value Fs by a predetermined constant A. Therefore, the change amount d of the driving force
Fa is a monotonically increasing quadratic function having (| FinR |-| Fs |) as an argument. Therefore, when the digital operation force signal is near the set value Fs, the responsiveness of the driving force can be suppressed, so that the operation of the electric wheelchair 1 can be stabilized, and as the digital operation force signal moves away from the set value Fs. Since the responsiveness of the driving force can be enhanced, a large amount of change in the driving force can be obtained by applying a large digital operating force signal, and the operability does not feel uncomfortable. Note that the coefficient K is the digital operation force signal Fin.
The difference between R and the set value Fs is raised to the power of m (m is an integer of 2 or more),
The absolute value of a value obtained by multiplying the result by a constant A may be used.

Although FIGS. 5, 7 to 9 show the case where the digital operating force signal is positive, when the digital operating force signal is negative, each dFa is determined using -FinR. Is done.

The processing performed by the control unit 18R to perform the above control will be described with reference to the flowchart shown in FIG. The same control is performed in the control unit 18L independently of the control unit 18R.

First, the input value is converted every time a predetermined sampling period is reached (step S2). That is, an operation force detection signal from the operation force detection unit 20R is input and converted into a digital operation force signal.

Next, it is determined whether the command driving force FoutR is 0 (step S3). Command driving force FoutR is 0
In step S4, it is determined whether the digital operation force signal FinR is positive or negative, and whether the motor 10R is to be moved forward (forward) or backward (reverse). As will be described later, if FoutR is not 0, the motor 10R already has
Since it is driven, it is not necessary to determine a new driving direction, so that step S4 is jumped.

Next, the absolute value of the digital operation force signal FinR is larger than the absolute value of the set value Fs, or Fou.
It is determined whether tR is not 0 (step S6). The answer to this determination is no because the digital operating force signal Fi
Only when the absolute value of nR is smaller than the absolute value of set value Fs and FoutR is 0. Therefore, after the absolute value of the digital operating force signal FinR becomes larger than the absolute value of the set value Fs and the motor 10R is driven, for example, the absolute value of the digital operating force signal FinR is changed to the set value Fs.
Even if the absolute value of s is smaller than the absolute value of s, since the motor 10R is driven, the answer to the determination in step S6 is YES.

If the answer to step S6 is yes, if the motor 10R is rotating forward, the calculation of FinR-Fs is performed, and if the motor 10R is rotating backward, -FinR-Fs is calculated.
The calculation of s is performed (step S8). This is a preliminary stage for obtaining the driving force change amount dFa.

Next, the coefficient K is taken in (step S10). That is, in the case of FIG. 5 or FIG. 7, which of the control regions C1 to C3 the FinR corresponds to, and in the case of FIG.
8 is determined by each threshold value, Fs-Fh and Fs + Fh in FIG. 5 or FIG. 7, and Fs in FIG.
s-Fh2, Fs-Fh1, Fs + Fh1, Fs + Fh
Judge based on 2.

Alternatively, in the case of FIG. 5 or FIG. 7, it is determined whether (FinR−Fs) is smaller than −Fh, not smaller than −Fh and not larger than Fh, and larger than Fh.
(FinR-Fs) is smaller than -Fh2 or -Fh2
The corresponding area can also be determined by determining whether it is greater than or equal to h2 and less than -Fh1, greater than or equal to -Fh1 and less than or equal to Fh1, greater than Fh1 and less than or equal to Fh2, or greater than Fh2. When the corresponding control region is determined, the coefficient K corresponding to the control region is determined.

In the case of FIG. 4, the coefficient K is constant, and step S10 can be omitted. In the case of FIG. 9, the coefficient K is determined as the absolute value of a value obtained by multiplying the difference between FinR and Fs by a constant A. In this step S10, instead of determining the control region,
The coefficient K may be calculated.

Next, the amount of change dFa is calculated using the difference obtained in step S8 and the coefficient K obtained in step S10.
(Step S12).

The change amount dFa thus obtained is added to the current driving force Fa (t-1) to calculate a new digital driving force signal Fa (t) (step S1).
4).

However, if the answer to the determination in step S6 is NO, the process jumps to step S14, in which case the digital driving force signal Fa (t) is set to 0.
Therefore, when FoutR is 0 and the digital operation force signal FinR has never exceeded the set value Fs or −Fs, the motor 10R is not driven. But,
Once the digital operation force signal exceeds the set value Fs and the motor 10R is driven, even if the digital operation force signal becomes smaller than the set value Fs, the motor 10R is driven.

In this way, the digital driving force signal Fa
When (t) is determined, it is converted to a PWM signal,
Supply to the motor drive unit 16R (Step S1
6). At this time, a direction signal indicating the rotation direction of the motor 10R determined based on the direction determined in step S4 is also supplied to the motor drive unit 16R.

That is, the PID operation is performed on Fa (t), and
It is converted into the command driving force FoutR (step S16
1). Next, it is determined whether or not FoutR is 0 or less (step S162). FoutR becomes 0 or less in the following cases, for example. That is, from the state in which FinR exceeding Fs occurs in the direction of rotating the motor 10R forward, for example, the operation force supplied to the operation force detection unit 20R becomes the reverse direction, and FinR becomes negative. When it becomes a value, dFa becomes a negative value. When the state where dFa is a negative value continues to some extent, the driving force Fa (t) becomes negative, and the command driving force FoutR also becomes negative. When FoutR becomes 0 or less, FoutR is set to 0 (step S163). If FoutR is 0 or less, the electric wheelchair is driven in the opposite direction as before, so that the electric wheelchair is prevented from running abruptly in the opposite direction, and the behavior of the electric wheelchair changes significantly. This is to prevent the electric current from flowing in the motor 10R in the opposite direction to the current, and to prevent the motor 10R from being damaged. At this time, the current driving force Fa (t) is also set to 0 at the same time. This FoutR is
It is converted into a PWM signal (step S164).

If FoutR is not less than 0, FoutR
Is determined to be equal to or greater than the maximum force MAX that can be output by the motor 10R (step S166). FoutR is MAX
Above, FoutR is set to MAX (step S
168), and in step S164, FoutR becomes P
It is converted to a WM signal. If FoutR is not equal to or greater than MAX, FoutR at that time is set in step S164.
Is converted into a PWM signal.

Based on the PWM signal and the direction signal thus supplied, the motor drive unit 16R performs PWM control on the motor 10R to generate a driving force corresponding to Fa (t) on the motor 10R.

In step S163, Fou
When tR is set to 0, the next time the processing of FIG. 10 is performed, it is determined that FoutR is 0 in step S3, and thus the current Fin is set in step S4.
R direction is determined, and the motor 10
R can be rotated. If the processing in FIG. 10 has been performed before, in step S163, Fa
Since (t) is set to 0, this corresponds to Fa at this time.
(T-1), and when the step S6 is executed, the new driving force Fa (t) increases from 0 even if the absolute value of FinR is larger than the absolute value of Fs. become.

In the above-described embodiment, FIGS.
Although any one of the relationships between the digital operation force signal and the amount of change in the driving force shown in FIG. 9 is used, the control unit is configured such that any of the relationships shown in each of the above drawings can be used.
A selected one of the above relationships may be used.

In the above embodiment, step S162
When it is determined in step S163 that the command driving force FoutR is equal to or less than 0, FoutR is set to 0 in step S163, and next time it is determined that FoutR is 0 in step S3, and the driving force is determined based on the direction of the operating force in step S4. The direction has been newly determined. According to this method, as in the above-described embodiment, a change amount dFa of the driving force is obtained based on the difference between FinR and Fs, and the current driving force Fa is calculated.
By adding dFa to (t-1), a new driving force Fa is added.
The present invention can be applied not only to the case where (t) is obtained, but also to a case where, for example, a driving force having a magnitude proportional to the operating force is output in the same direction as the operating force. In addition, in calculating the new driving force Fa (t), the current driving force Fa (t−
1) was used, but instead of this, the current command driving force Fo
Using utR (t-1), a new driving force Fa (t) is expressed by F
It can also be calculated by outR (t-1) + dFa.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a control device for an electric vehicle according to the present invention.

FIG. 2 is a perspective view of an electric wheelchair implementing the control device of the embodiment.

FIG. 3 is a diagram showing a relationship between an operation force detection signal and an operation force input to the control device of the embodiment.

FIG. 4 is a diagram showing a first example of a relationship between a digital operation force signal and a driving force change amount in the control device of the embodiment.

FIG. 5 is a diagram showing a second relationship between the digital operation force signal and the amount of change in the driving force in the control device of the embodiment.

6 and FIG. 5 in the control device of the embodiment.
FIG. 8 is a diagram showing a relationship between the operating force and the driving force when the relationship between the driving force and the digital operating force signal is set to change.

FIG. 7 is a diagram showing a third example of the relationship between the digital operation force signal and the amount of change in the driving force in the control device of the embodiment.

FIG. 8 is a diagram showing a fourth example of the relationship between the digital operation force signal and the amount of change in the driving force in the control device of the embodiment.

FIG. 9 is a diagram showing a fifth example of the relationship between the digital operation force signal and the amount of change in the driving force in the control device of the embodiment.

FIG. 10 is a flowchart showing an operation of the control device of the embodiment.

[Explanation of symbols]

 10R 10L Motor (drive unit) 12R 12L Controller 18R 18L Controller

Claims (11)

[Claims] 1. A control device for an electric vehicle provided with a control unit for generating, in a drive unit, a driving force for supplementing the operation force when an operation force when a person propels the vehicle reaches a set value. The control unit calculates a change amount of the driving force by subtracting the set value from the operating force, and calculates a new driving force by adding the change amount to the driving force. A control device for an electric vehicle. 2. The control unit calculates a change amount of a driving force that monotonically increases by multiplying a value obtained by subtracting the set value from the operation force by an arbitrary coefficient, and uses the change amount as the driving force. The control device for an electric vehicle according to claim 1, wherein a new driving force is calculated by taking into account the driving force. 3. A control device for an electric vehicle provided with a control unit for generating, in a drive unit, a driving force for supplementing the operation force when the operation force when a person propels the vehicle reaches a set value. The control unit sets an arbitrary number of thresholds, and sets a plurality of control areas defined by the thresholds,
A value obtained by subtracting a set value from the operating force is multiplied by an arbitrary coefficient determined for each control region to calculate a monotonically increasing amount of change in the driving force, and the amount of change is added to the driving force. Thus, a control device for an electric vehicle that calculates a new driving force. 4. The control device for an electric vehicle according to claim 3, wherein a coefficient of the control region including the set value is set to be smaller than a coefficient of the control region not including the set value. 5. The control device for an electric vehicle according to claim 4, wherein a coefficient of the control region including the set value is substantially zero. 6. The control area is formed in three or more sections, and a coefficient of the control area including the set value and a coefficient of the control area farthest from the set value are set to be smaller than coefficients of other control areas. The control device for an electric vehicle according to claim 3, which is reduced in size. 7. A control device for an electric vehicle provided with a control unit for generating, in a drive unit, a driving force for supplementing the operation force when the operation force when a person propels the vehicle reaches a set value. The control unit calculates a change amount of the driving force obtained as a monotonically increasing portion of an n-dimensional function in which n is 2 or more by multiplying a value obtained by subtracting the set value from the operating force by an arbitrary coefficient. An electric vehicle control device for calculating a new driving force by adding the amount of change to the driving force. 8. A control unit is provided, wherein when the operation force when a person propells the vehicle reaches a set value, the drive unit generates a driving force in a predetermined direction and magnitude to supplement the operation force. In the control device for an electric vehicle, the control unit calculates a change amount of the driving force by subtracting the set value from the operation force, and adds the change amount to the driving force to obtain a predetermined amount. A control device for an electric vehicle that calculates a new driving force in the direction and magnitude of the vehicle. 9. The control unit detects a direction of the operating force based on a determination result that the driving unit does not generate a driving force, and changes the direction of the driving force according to the direction of the operating force. The control device for an electric vehicle according to claim 8, wherein the control device is determined. 10. The control of the electric vehicle according to claim 9, wherein the control unit temporarily sets the driving force to zero when the new driving force direction is different from the determined driving force direction. apparatus. 11. A direction and a magnitude of an operating force applied to a vehicle when a person propells the vehicle, and a driving force in a predetermined direction and a magnitude is calculated based on the detected operating force. In a control device for an electric vehicle provided with a control unit that generates a driving force, the control unit may determine a direction of the operating force based on a determination result that the driving unit does not generate a driving force. The direction of the driving force is determined accordingly, and when the direction of the newly calculated driving force based on the operating force is different from the determined direction of the driving force, the driving force is temporarily set to zero. A control device for an electric vehicle.