Motor control device for electric assist vehicle and electric assist vehicle

Abstract

In order to automatically perform regeneration in a moderate range even on a gentle downhill or flat ground, this motor control device has: a driving unit that performs driving or regeneration for a motor; and a control unit that sets a vehicle speed as a reference speed during a transition to a predetermined traveling or pedal operation state, and controls the driving unit to generate regenerative torque while the vehicle speed is between the reference speed and a lower limit speed determined on the basis of the reference speed. Another motor control device has a driving unit that performs driving or regeneration for a motor; and a control unit that sets a vehicle speed as a reference speed during a transition to a predetermined traveling or pedal operation state, and controls the driving unit to generate regenerative torque within a certain period of time from a timing when the vehicle speed becomes less than the reference speed or within a certain length of the traveling distance from said timing.

Description

Technical Field

[0001] The present invention relates to regenerative control technology for an electric assist vehicle.

Background Art

[0002] For example, in Patent Document 1, when a state where a pedal torque input less than a first threshold value continues for a certain period of time, a state where a pedal torque input less than a second threshold value and a pedal rotation angle less than a third threshold value continue for a certain period of time, or a state where it is determined that the degree of coincidence or divergence between a first value corresponding to wheel rotation and a second value corresponding to pedal rotation is different by a predetermined level or more, the vehicle speed at the time of detection of that state is set as a reference speed, and when the current vehicle speed exceeds the reference speed, regeneration is performed with a regeneration amount corresponding to the difference between the reference speed and the current vehicle speed. A technique is disclosed.

[0003] In addition, Patent Document 2 discloses a technique in which regeneration is turned on when a condition {wheel speed, which is the vehicle speed estimated from the rotation of the wheel} > {crank speed, which is the vehicle speed estimated from the rotation of the crank} + α1 is satisfied, and regeneration is turned off when this condition is not satisfied. In addition, as a condition for turning on regeneration, conditions such as the vehicle speed being equal to or higher than a threshold value, the condition that the previous crank speed + α3 ≥ the current crank speed, and the condition that a weak assist mode for increasing the opportunity of regenerative charging is set may be added.

[0004] In the case of Patent Document 1 described above, when assuming a gentle downhill (for example, a road where an electric assist bicycle can travel without pedaling due to the influence of gravity and inertia) as the actual driving situation, when the electric assist bicycle accelerates from the reference speed, regeneration is performed and charging of the battery is performed. However, thereafter, for example, when the downhill becomes gentler or the running resistance due to the headwind increases, a change in the running state occurs and deceleration occurs, and when the vehicle speed falls below the reference speed, regeneration is not performed and the opportunity to charge the battery is missed.

[0005] On the other hand, in the case of Patent Document 2, assuming, for example, a gentle downhill slope or flat ground, regeneration will occur as long as the conditions described above are met. In this case, the braking force due to regeneration will exceed the forward force of the electric assist bicycle, resulting in excessive deceleration. In this case, it is not possible to maintain speed as with a normal bicycle. Therefore, the rider has to perform operations such as increasing the crank speed in order to stop regeneration, which is troublesome. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Public Publication WO / 2020 / 017445 [Patent Document 2] Japanese Patent Publication No. 2017-088155 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, in one aspect, the object of the present invention is to provide a technology for automatically performing regeneration within an appropriate range, for example, on a gentle downhill slope or on flat ground. [Means for solving the problem]

[0008] A motor control device according to a first aspect of the present invention includes a drive unit that drives or regenerates a motor, and a control unit that sets the vehicle speed when transitioning to a predetermined driving or pedal operation state as a reference speed, and controls the drive unit to generate regenerative torque when the vehicle speed is between the reference speed and a lower limit speed determined based on the reference speed.

[0009] A motor control device according to a second aspect of the present invention includes a drive unit that drives or regenerates a motor, and a control unit that sets the vehicle speed at the time of transition to a predetermined driving or pedal operation state as a reference speed, and controls the drive unit to generate regenerative torque within a certain time period from the moment the vehicle speed falls below the reference speed or within a certain distance traveled from the moment. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows the external appearance of an electric assist bicycle in an embodiment. [Figure 2] Figure 2 shows an example of the configuration of a motor control device. [Figure 3] Figure 3 shows the functional configuration related to the regenerative control unit in the embodiment. [Figure 4] Figure 4 is a diagram showing a flow chart illustrating the operation in the first embodiment. [Figure 5] Figure 5 shows the processing flow of the control permission determination process. [Figure 6] Figure 6 shows an example of the relationship between the regenerative braking coefficient and the current vehicle speed. [Figure 7] Figure 7 is a diagram illustrating the flow of operations in the second embodiment. [Figure 8] Figure 8 is a time chart showing a comparison between the prior art and the present invention. [Figure 9] Figure 9 is a time chart showing a comparison between the conventional technology and the present invention. [Figure 10] Figure 10 is a time chart showing a comparison between the conventional technology and the present invention. [Figure 11] Figure 11 is a diagram showing a flow chart illustrating the operation in the third embodiment. [Figure 12] Figure 12 shows the processing flow of the first generation coefficient setting process A. [Figure 13] Figure 13 is a diagram showing a flow chart illustrating the operation in the fourth embodiment. [Figure 14] FIG. 14 is a diagram showing the processing flow of the second regeneration coefficient setting process A. [Figure 15] FIG. 15 is a diagram showing the processing flow of the first regeneration coefficient setting process B. [Figure 16] FIG. 16 is a diagram showing an example of the change of the regeneration coefficient over time or distance. [Figure 17] FIG. 17 is a diagram showing the processing flow of the second regeneration coefficient setting process B. [Figure 18] FIG. 18 is a diagram showing a flow representing the operation content in the seventh embodiment. [Figure 19] FIG. 19 is a diagram showing an example of the relationship between the battery remaining capacity SOC and the ratio of ΔV to ΔV with respect to the reference speed.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described by taking an example of an electric assist bicycle, which is an example of an electric assist vehicle. However, the embodiments of the present invention are not limited to being applied only to electric assist bicycles, and are also applicable to a motor control device or the like for a motor that assists the movement of a moving body (for example, a cart, a wheelchair, a lift, etc.) that moves in response to human power.

[0012] [Embodiment 1] FIG. 1 is an external view showing an example of an electric assist bicycle, which is an example of an electric assist vehicle in the present embodiment. This electric assist bicycle 1 is equipped with a motor drive device. The motor drive device includes a battery pack 101, a motor control device 102, a torque sensor 103, a pedal rotation sensor 104, a motor 105, and an operation panel 106. Note that the electric assist bicycle 1 may have a brake sensor 107, but it is not used in the present embodiment.

[0013] Further, the electric assist bicycle 1 also has a front wheel, a rear wheel, a headlight, a freewheel, a transmission, etc.

[0014] The battery pack 101 is, for example, a lithium-ion secondary battery, but it may also be a different type of battery, such as a lithium-ion polymer secondary battery or a nickel-metal hydride storage battery. The battery pack 101 supplies power to the motor 105 via the motor control device 102, and during regeneration, it is also charged by the regenerative power from the motor 105 via the motor control device 102.

[0015] The torque sensor 103 is located around the crankshaft and detects the pedal force applied by the driver, outputting the detection result to the motor control device 102. Similarly, the pedal rotation sensor 104 is located around the crankshaft and outputs a signal corresponding to the rotation to the motor control device 102.

[0016] Motor 105 is, for example, a well-known three-phase DC brushless motor, and is mounted, for example, on the front wheel of an electric assist bicycle 1. Motor 105 rotates the front wheel, and the rotor is connected to the front wheel so that the rotor rotates in accordance with the rotation of the front wheel. Furthermore, motor 105 is equipped with a rotation sensor such as a Hall element and outputs rotor rotation information (i.e., a Hall signal) to the motor control device 102.

[0017] The motor control device 102 performs predetermined calculations based on signals from the motor 105's rotation sensor, torque sensor 103, pedal rotation sensor 104, etc., to control the drive of the motor 105 and also controls regenerative braking by the motor 105.

[0018] The control panel 106 receives inputs from the passenger, such as instructions regarding the presence or absence of assistance (i.e., turning the power switch on and off), and, if assistance is enabled, the desired assistance ratio, and outputs these instructions to the motor control device 102. The control panel 106 may also have a function to display data such as distance traveled, travel time, calories consumed, and regenerative power, which are calculated by the motor control device 102. The control panel 106 may also have a display unit using LEDs (Light Emitting Diodes), for example. This displays information to the driver, such as the charge level of the battery pack 101, its on / off status, and the mode corresponding to the desired assistance ratio.

[0019] Figure 2 shows the configuration related to the motor control device 102 according to this embodiment. The motor control device 102 includes a controller 1020 and an FET (Field Effect Transistor) bridge 1030. The FET bridge 1030 includes a high-side FET (Suh) and a low-side FET (Sul) that perform switching for the U-phase of the motor 105, a high-side FET (Svh) and a low-side FET (Svl) that perform switching for the V-phase of the motor 105, and a high-side FET (Swh) and a low-side FET (Swl) that perform switching for the W-phase of the motor 105. This FET bridge 1030 is the motor drive unit and constitutes part of a complementary switching amplifier.

[0020] Furthermore, the controller 1020 includes a calculation unit 1021, a pedal rotation input unit 1022, a motor rotation input unit 1024, a variable delay circuit 1025, a motor drive timing generation unit 1026, a torque input unit 1027, an AD (Analog-Digital) input unit 1029 for AD conversion of the output voltage of the battery pack 101, and a communication unit 1028 with the battery pack 101.

[0021] The calculation unit 1021 performs predetermined calculations using inputs from the operation panel 106 (e.g., assist on / off), the pedal rotation input unit 1022, the motor rotation input unit 1024, the torque input unit 1027, the communication unit 1028, and the AD input unit 1029, and outputs to the motor drive timing generation unit 1026 and the variable delay circuit 1025. The calculation unit 1021 also has a memory 10211, which stores various data used for calculations and data in the process of processing. Furthermore, the calculation unit 1021 may be implemented by a processor executing a program, in which case the program may be recorded in the memory 10211. In addition, the memory 10211 may be provided separately from the calculation unit 1021.

[0022] The pedal rotation input unit 1022 digitizes the pedal rotation phase angle (also simply called the pedal rotation angle or crank rotation phase angle; this may include a signal indicating the direction of rotation) from the pedal rotation sensor 104 and outputs it to the calculation unit 1021. The motor rotation input unit 1024 digitizes signals related to the rotation of the motor 105 (in this embodiment, the rotation of the front wheel) from the Hall signal output by the motor 105 (e.g., rotation phase angle, rotation direction) and outputs them to the calculation unit 1021. The torque input unit 1027 digitizes the signal corresponding to the pedaling force from the torque sensor 103 and outputs it to the calculation unit 1021. The AD input unit 1029 digitizes the output voltage from the secondary battery and outputs it to the calculation unit 1021. Furthermore, the communication unit 1028 receives data such as the battery remaining capacity SOC (State of Charge) from the communication terminal of the battery pack 101 and outputs it to the calculation unit 1021.

[0023] The calculation unit 1021 outputs an advance angle value as a calculation result to the variable delay circuit 1025. The variable delay circuit 1025 adjusts the phase of the Hall signal based on the advance angle value received from the calculation unit 1021 and outputs it to the motor drive timing generation unit 1026. The calculation unit 1021 outputs a PWM code, for example, corresponding to the duty cycle of PWM (Pulse Width Modulation), to the motor drive timing generation unit 1026 as a calculation result. The motor drive timing generation unit 1026 generates and outputs switching signals for each FET included in the FET bridge 1030 based on the adjusted Hall signal from the variable delay circuit 1025 and the PWM code from the calculation unit 1021. Depending on the calculation result of the calculation unit 1021, the motor 105 may be driven or regeneratively braked. The basic operation of the motor is described in International Publication No. 2012 / 086459, etc., and is not the main part of this embodiment, so it will not be explained here.

[0024] Next, Figure 3 shows an example of the functional block configuration related to the regenerative control unit 3000 in the calculation unit 1021 (the part relating to this embodiment). The regenerative control unit 3000 includes a regenerative target calculation unit 3100, a reference speed setting unit 3200, and a control unit 3300. The calculation unit 1021 also has a motor rotation processing unit 2000 that calculates the rotation speed of the motor 105 (rotation speed of the front wheel), the speed of the electric assist bicycle 1 (=vehicle speed), and acceleration (amount of change of speed over time) from the motor rotation input from the motor rotation input unit 1024.

[0025] The regenerative target calculation unit 3100 identifies and outputs a predetermined regenerative target torque (also called the regenerative target amount) based on the current vehicle speed or acceleration, etc. The reference speed setting unit 3200 sets the reference speed, which is the speed used as a reference for regenerative control. The reference speed setting unit 3200 sets the current vehicle speed as the reference speed V0 when the front wheel rotation speed (hereinafter also called the wheel rotation speed) or vehicle speed and the rear wheel rotation speed converted based on pedal rotation (the rotation speed obtained by converting pedal rotation to the rear wheel rotation speed based on the gear ratio, etc., and is also called the pedal-converted rotation speed) or rear wheel vehicle speed (also called the pedal-converted speed (speed obtained by converting pedal rotation to vehicle speed based on the gear ratio, etc.)) have a predetermined relationship. In the following explanation, the current vehicle speed is set as the reference speed V0 when the relationship front wheel rotation speed - pedal-converted rotation speed > threshold transitions from a state where it does not hold to a state where it holds, with rotation speed as the reference. Furthermore, the reference speed setting unit 3200 turns on and off a flag indicating whether or not to perform regenerative control based on the front wheel speed, pedal torque, and the above-mentioned relationship.

[0026] The control unit 3300 calculates the instructed regenerative torque to be generated by the motor 105 based on the reference speed and the value of the flag from the reference speed setting unit 3200, the speed from the motor rotation processing unit 2000, and the regenerative target torque from the regenerative target calculation unit 3100, and performs regenerative control according to the instructed regenerative torque. In this embodiment, the control unit 3300 determines a regenerative coefficient from the obtained data and calculates the instructed regenerative torque by multiplying the regenerative coefficient by the regenerative target torque. The control unit 3300 may also perform regenerative control based on other perspectives in addition to the regenerative control according to this embodiment. For example, if the current vehicle speed is equal to or greater than the reference speed V0, the control unit may control the motor so that an instructed regenerative torque corresponding to the current vehicle speed minus the reference speed V0 is generated.

[0027] When regeneration is not performed, the calculation unit 1021 drives the motor 105 via the motor drive timing generation unit 1026, variable delay circuit 1025, and FET bridge 1030 to perform conventional power driving. On the other hand, when regeneration is performed, the calculation unit 1021 regenerate-controls the motor 105 via the motor drive timing generation unit 1026, variable delay circuit 1025, and FET bridge 1030 to achieve the instructed regenerative torque output by the control unit 3300.

[0028] Furthermore, in other embodiments described later, the control unit 3300 also performs processing according to the remaining battery capacity SOC received from the battery pack 101 via the communication unit 1028.

[0029] In this embodiment, regeneration is performed not only when the vehicle speed is equal to or greater than the reference speed V0, but also when the vehicle speed is below the reference speed V0. Furthermore, since the lower limit speed at which regeneration is performed is set based on the reference speed V0, the occupant does not need to perform any operation to stop regeneration. Moreover, compared to cases where the lower limit speed is set independently of the reference speed V0, there is no risk of excessive deceleration due to regenerative braking or no regenerative braking at all.

[0030] The control details of the regenerative control unit 3000, etc., will be explained in detail below using Figures 4 to 6. Steps S1 to S21 are executed for each control cycle.

[0031] First, the reference speed setting unit 3200 calculates the pedal-equivalent rotation speed from the pedal rotation input and receives the wheel rotation speed from the motor rotation processing unit 2000, and determines whether the relationship (wheel rotation speed - pedal-equivalent rotation speed) > threshold TH1 (for example, 40 rpm) has transitioned from a state where it is not true to a state where it is true (step S1). If the relationship (wheel rotation speed - pedal-equivalent rotation speed) > threshold TH1 continues to be true, or if it is not true, the process proceeds to step S5.

[0032] On the other hand, if the relationship (wheel rotation speed - pedal equivalent rotation speed) > threshold TH1 transitions from a state where it is not true to a state where it is true, the reference speed setting unit 3200 sets the current vehicle speed V from the motor rotation processing unit 2000 to the reference speed V0 and outputs it to the control unit 3300 (step S3).

[0033] Then, the reference speed setting unit 3200 executes a control permission determination process to determine whether or not to permit regenerative control (step S5). The control permission determination process will be explained using Figure 5.

[0034] First, the reference speed setting unit 3200 determines whether (wheel rotations - pedal-equivalent rotations) > threshold TH1 (step S31). If this condition is not met, the reference speed setting unit 3200 sets a flag to OFF to indicate that regenerative control is not permitted (step S39). Then it returns to the calling process.

[0035] On the other hand, if the conditions of step S31 are met, the reference speed setting unit 3200 determines from the pedal torque input whether the pedal torque < threshold TH2 (for example, 20 Nm) (step S33). If the pedal torque is greater than or equal to threshold TH2, it is presumed that the occupant intends to accelerate, so the process proceeds to step S39.

[0036] On the other hand, if pedal torque < threshold TH2, the reference speed setting unit 3200 determines whether vehicle speed > threshold TH3 (for example, 8 km / h) (step S35). If the vehicle speed is less than or equal to threshold TH3, the vehicle will decelerate too much due to regenerative braking, so the process proceeds to step S39.

[0037] If the vehicle speed is greater than the threshold TH3, the reference speed setting unit 3200 can perform regenerative control, so it sets the flag to ON (step S37). Then the process returns to the calling process.

[0038] In this way, whether or not to allow regenerative control is notified from the reference speed setting unit 3200 to the control unit 3300 using a flag.

[0039] Returning to the explanation of the process in Figure 4, the control unit 3300 determines whether the flag is on or off (step S7). If the flag set by the reference speed setting unit 3200 is off, the control unit 3300 sets the regeneration coefficient to 0 (step S17). Then the process moves on to step S19.

[0040] If the flag is on, the control unit 3300 determines whether the current vehicle speed V from the motor rotation processing unit 2000 is greater than or equal to the reference speed V0 (step S9). If the current vehicle speed V is greater than or equal to the reference speed V0, the control unit 3300 sets the regenerative coefficient according to a predetermined rule (step S11). This step is, for example, the same as in the prior art, and the regenerative coefficient is set according to the current vehicle speed V - reference speed V0. However, the regenerative coefficient may be set to 1.0. In cases where the regenerative coefficient is to be gradually increased, the regenerative coefficient may be gradually brought closer to 1.0 along a predetermined curve.

[0041] Then, the control unit 3300 calculates the instructed regenerative torque by multiplying the regenerative target torque calculated by the regenerative target calculation unit 3100 from the vehicle speed, etc., by a regenerative coefficient (step S19). The braking force to be generated by the motor 105 is specified by this instructed regenerative torque.

[0042] The regenerative control unit 3000 then determines whether or not processing has been instructed to end due to a power outage or other reason (step S21). If processing has not been instructed to end due to a power outage or other reason, processing returns to step S1. On the other hand, if processing has been instructed to end due to a power outage or other reason, processing is terminated.

[0043] On the other hand, if it is determined in step S9 that the current vehicle speed V is less than the reference speed V0, the control unit 3300 determines whether the current vehicle speed V ≥ the reference speed V0 - ΔV (for example, 2 km / h) (step S13). In this embodiment, ΔV is set to a fixed value. V0 - ΔV represents the lower limit speed based on the reference speed V0, and determines whether the current vehicle speed V is equal to or greater than the lower limit speed based on the reference speed V0. If the current vehicle speed V is less than the lower limit speed, the process moves to step S17, and the regenerative coefficient is set to 0.

[0044] On the other hand, if the current vehicle speed V is equal to or greater than the lower limit speed, the control unit 3300 sets the regenerative coefficient to (V - (V0 - ΔV)) / ΔV (step S15). In other words, it sets the regenerative coefficient according to (current vehicle speed V - lower limit speed). Then the process moves to step S19. However, this formula is just one example. That is, this is an example in which the regenerative coefficient increases linearly as the difference between the current vehicle speed V and the lower limit speed increases, but it may also be made to change curvilinearly.

[0045] The variations in the regenerative coefficient set in step S15 will be explained using Figure 6. Figure 6 is a diagram showing the relationship between the current vehicle speed V and the regenerative coefficient. The (V-(V0-ΔV)) / ΔV mentioned above is represented by the solid line b. That is, as the current vehicle speed V decelerates from the reference speed V0, the regenerative coefficient gradually decreases, and when it reaches the reference speed V0-ΔV (i.e., the lower limit speed), the regenerative coefficient becomes 0. Alternatively, as shown by the thick line c, the regenerative coefficient may be maintained at 1.0 if the current vehicle speed V is only slightly below the reference speed V0, but the regenerative coefficient may decrease linearly as the difference between the current vehicle speed V and the lower limit speed decreases, and when it reaches the reference speed V0-ΔV (i.e., the lower limit speed), the regenerative coefficient may become 0. Furthermore, as shown by the dotted line d, the regenerative coefficient may be maintained at 1.0 until the current vehicle speed V reaches the lower limit speed, at which point the regenerative coefficient may be set to 0.

[0046] Also, for example, if the current vehicle speed V is initially equal to or higher than the reference speed V0, and after the regeneration coefficient is set to x (0 < x < 1, for example, 0.3) in step S11, the current vehicle speed V becomes lower than the reference speed V0, the regeneration coefficient may be set to x*(V - (V0 - ΔV)) / ΔV. In this case, it becomes the solid line a in FIG. 6. That is, when the current vehicle speed V is equal to the reference speed V0, it becomes x (= 0.3), and then as the speed decreases, the regeneration coefficient gradually decreases, and when the current vehicle speed V reaches the lower limit speed, the regeneration coefficient becomes 0.

[0047] In this way, until the current vehicle speed V reaches the lower limit speed set based on the reference speed V0, the regeneration coefficient becomes a value exceeding 0, and regeneration is performed. That is, the scenes where regeneration is performed increase, and the charge amount for the battery pack 101 increases. Also, since the lower limit speed is set based on the reference speed V0, the passenger does not have to instruct to stop the regeneration himself / herself. Further, compared with the case where the lower limit speed is set regardless of the reference speed V0, the situation where deceleration due to regenerative braking is too strong or regenerative braking is not applied is eliminated.

[0048] [Embodiment 2] In the first embodiment, since ΔV is fixed, when the reference speed V0 is low, it may be excessive with respect to the reference speed V0. In this embodiment, for example, an example of setting a certain ratio r of the reference speed V0 as ΔV is shown.

[0049] The control content of this embodiment is shown in FIG. 7. However, since it is almost the same as FIG. 4, only the different parts are shown. The added process is step S25. After it is determined in step S9 that the current vehicle speed V is lower than the reference speed V0, the control unit 3300 sets a value obtained by multiplying r (for example, 0.1) by the reference speed V0 as ΔV (step S25). Then the process proceeds to step S13.

[0050] In this way, since ΔV is set as a constant ratio r of the reference speed V0, even when the reference speed V0 is low, it is possible to avoid a situation where an excessively large ΔV is set relative to the reference speed V0, resulting in an excessively low lower speed limit.

[0051] Here, the effects of this embodiment will be explained by showing an example of regenerative control in this embodiment and an example of regenerative control in Patent Documents 1 and 2 (referred to as Prior Art 1 and 2 in the figures).

[0052] Figure 8(a) shows an example of pedal operation, specifically a scenario where pedal rotation is stopped while riding at 20 km / h on flat ground. When pedal rotation is stopped while riding on flat ground, a typical bicycle will gradually decelerate naturally.

[0053] In the case of the electric assist bicycle 1 described in Patent Document 1 (Prior Art 1), a reference speed V0 = 20 km / h is set when pedaling is stopped while pedaling is in progress. However, as shown in Figure 8(b), regenerative control is not performed unless the vehicle speed is equal to or greater than the reference speed V0, so the bicycle gradually decelerates naturally, just like a regular bicycle.

[0054] On the other hand, in the case of the electric assist bicycle (Case 1) described in Patent Document 2 (Prior Art 2), no reference speed is set, and as shown in Figure 8(c), regenerative control is turned on regardless of the vehicle speed, so regenerative braking causes a more rapid deceleration than the natural deceleration shown in Figure 8(b). If the pedal operation to turn off regenerative control is not performed, regenerative control will continue unless the vehicle speed falls below a separately set lower limit speed. If a lower limit speed is not set, excessive deceleration may occur.

[0055] On the other hand, as shown in Figure 9(a), consider a case where the pedals are rotated only slightly after they have stopped. In the case of the electric assist bicycle (Case 2) described in Patent Document 2 (Prior Art 2), this triggers the turning off of regenerative control. Therefore, as shown in Figure 9(b), when the trigger for turning off regenerative control is detected, the regenerative control is turned off, and the vehicle speed subsequently changes to a natural deceleration.

[0056] In contrast, in this embodiment, when the reference speed V0 is set to 20 km / h, if r=0.1, the lower limit speed becomes 18 km / h. As shown in Figure 9(c), regenerative control is performed up to the current vehicle speed V of 18 km / h, but as soon as it falls below 18 km / h, regenerative control is stopped and the vehicle transitions to natural deceleration. In this way, regenerative control can be automatically stopped without the occupant having to perform operations such as those described in Patent Document 2 (Prior Art 2).

[0057] Next, let's assume that in Patent Document 2 (Prior Art 2), the lower limit speed for regenerative control is fixed at 15 km / h. Let's also assume that the pedal operation shown in Figure 8(a) is performed. In this case, as shown in Figure 10(a), in Case 3 of Patent Document 2 (Prior Art 2), the regenerative control is turned off when the vehicle speed decelerates from 20 km / h to 15 km / h. This may cause the occupant to feel that the deceleration is excessive.

[0058] On the other hand, in this embodiment, as shown in Figure 9(c) and also in Figure 10(b), regenerative control is performed up to a current vehicle speed V of 18 km / h, but as soon as the speed falls below 18 km / h, regenerative control is stopped and the vehicle transitions to natural deceleration. In this way, regenerative control can be automatically stopped without the occupant having to perform operations such as those described in Patent Document 2 (Prior Art 2).

[0059] Next, let's consider the case where the pedal rotation is stopped while driving at 15 km / h on flat ground. In the case where the lower limit speed is set to 15 km / h in Patent Document 2 (Prior Art 2) (Case 4), as shown in Figure 10(c), regenerative control is not performed, and only natural deceleration occurs.

[0060] On the other hand, in this embodiment, the reference speed V0 = 15 km / h, so if r = 0.1, the lower limit speed is 13.5 km / h. Therefore, as shown in Figure 10(d), when the current vehicle speed V falls below 15 km / h, regenerative control is turned on, and remains on until the current vehicle speed V reaches 13.5 km / h. When the current vehicle speed V reaches 13.5 km / h, regenerative control is automatically turned off, and the vehicle decelerates naturally. Thus, regenerative control is performed, but it is automatically stopped to prevent excessive deceleration.

[0061] [Embodiment 3] In the first and second embodiments, a reference speed V0 is set, and regeneration is performed when the current vehicle speed V is less than the reference speed V0 but above the lower limit speed. However, there are cases where it is undesirable to maintain regenerative braking for a long period of time. This embodiment shows an example in which regeneration is performed only for a certain period of time after the current vehicle speed V falls below the reference speed V0.

[0062] The control details of the regenerative control unit 3000 and other components will be explained in detail below using Figure 11. Steps S51 to S67 are executed for each control cycle.

[0063] First, the reference speed setting unit 3200 calculates the pedal-equivalent rotation speed from the pedal rotation input and receives the wheel rotation speed from the motor rotation processing unit 2000, and determines whether the relationship (wheel rotation speed - pedal-equivalent rotation speed) > threshold TH1 (for example, 40 rpm) has transitioned from a state where it is not true to a state where it is true (step S51). If the relationship (wheel rotation speed - pedal-equivalent rotation speed) > threshold TH1 continues to be true, or if it is not true, the process proceeds to step S55.

[0064] On the other hand, if the relationship (wheel rotation speed - pedal equivalent rotation speed) > threshold TH1 transitions from a state where it is not true to a state where it is true, the reference speed setting unit 3200 sets the current vehicle speed V from the motor rotation processing unit 2000 to the reference speed V0 and outputs it to the control unit 3300 (step S53).

[0065] Then, the reference speed setting unit 3200 executes a control permission determination process to determine whether or not to allow regenerative control (step S55). The control permission determination process is the same as the process in Figure 5.

[0066] The control unit 3300 then determines whether the flag is on or off (step S57). If the flag is off, the control unit 3300 sets the regeneration coefficient to 0 (step S71). The control unit 3300 also initializes the time t from the point in time when the current vehicle speed V falls below the reference speed V0 to 0 (step S73). Then the process proceeds to step S65.

[0067] On the other hand, if the flag is on, the control unit 3300 determines whether the current vehicle speed V is equal to or greater than the reference speed V0 (step S59). If the current vehicle speed V is equal to or greater than the reference speed V0, the control unit 3300 sets the regeneration coefficient according to a predetermined rule (step S61). This step is as described in step S11. Furthermore, the control unit 3300 initializes the time t from the point in time when the current vehicle speed V fell below the reference speed V0 to 0.

[0068] Then, the control unit 3300 calculates the instructed regenerative torque by multiplying the regenerative target torque calculated from the vehicle speed, etc., by the regenerative coefficient (step S65). The braking force to be generated by the motor 105 is specified by this instructed regenerative torque.

[0069] The regenerative control unit 3000 then determines whether or not processing has been instructed to end due to a power outage or other reason (step S67). If processing has not been instructed to end due to a power outage or other reason, processing returns to step S51. On the other hand, if processing has been instructed to end due to a power outage or other reason, processing is terminated.

[0070] On the other hand, if it is determined in step S59 that the current vehicle speed V is less than the reference speed V0, the control unit 3300 executes a first regenerative coefficient setting process to set the regenerative coefficient according to the time (step S69). After that, the process proceeds to step S65.

[0071] Figure 12 shows the first generation coefficient setting process A according to this embodiment.

[0072] The control unit 3300 determines whether time t is less than or equal to the threshold TH11 (for example, 3 seconds) (step S81). Note that the initial value of time t is 0. If time t exceeds the threshold TH11, the control unit 3300 sets the regeneration coefficient to 0 (step S91). Then, the process returns to the calling process.

[0073] On the other hand, if time t is less than or equal to the threshold TH11, the control unit 3300 determines whether the current vehicle speed V ≥ reference speed V0 - ΔV (for example, 5 km / h) (step S83). In this embodiment, ΔV is set to a fixed value, but it may also be a predetermined ratio r of the reference speed V0, as in the second embodiment. If the current vehicle speed V is less than the lower limit speed, the control unit 3300 sets the regeneration coefficient to 0 (step S89). Then the process moves to step S87.

[0074] On the other hand, if the current vehicle speed V is equal to or greater than the lower limit speed, the control unit 3300 sets the regenerative coefficient to (V - (V0 - ΔV)) / ΔV (step S85). That is, it sets the regenerative coefficient according to (current vehicle speed V - lower limit speed). Then, the control unit 3300 increments the time t by one control cycle (step S87). Then, the process returns to the calling process. Step S85 is the same as step S15 in the first embodiment, and variations as shown in Figure 6 may be adopted, or it may be changed curvilinearly.

[0075] In this way, regeneration is performed if the time t from the point when the current vehicle speed V falls below the reference speed V0 is less than or equal to the threshold TH11. However, if the time t exceeds the threshold TH11, regeneration will not be performed even if the current vehicle speed V is above the lower limit speed but below the reference speed V0. In other words, the regeneration that occurs when the current vehicle speed V falls below the reference speed V0 can be limited to a certain period of time, and by preventing regenerative braking from continuing for too long, deceleration can be suppressed.

[0076] [Embodiment 4] In the third embodiment, the decision to stop regenerative braking was based on the time t from the point when the current vehicle speed V fell below the reference speed V0. However, the decision to stop regenerative braking may also be based on the distance d traveled from the point when the current vehicle speed V fell below the reference speed V0.

[0077] Figure 13 shows the control details of the regenerative control unit 3000, etc., but the difference from Figure 11 is not significant, so only the differences will be explained.

[0078] In this embodiment, since distance traveled d is used instead of time t, instead of step S65, the control unit 3300 initializes the distance traveled d from the point in time when the current vehicle speed V falls below the reference speed V0 to 0 (step S101).

[0079] Furthermore, instead of the first regeneration coefficient setting process in step S69 which is performed according to time t, the control unit 3300 performs a second regeneration coefficient setting process which sets the regeneration coefficient according to the travel distance d (step S103). In addition, after step S71, instead of step S73, the control unit 3300 initializes the travel distance d to 0 (step S105).

[0080] The second regeneration coefficient setting process A according to this embodiment will be explained with reference to Figure 14.

[0081] The control unit 3300 updates the travel distance d by the previous travel distance d + (current vehicle speed V × control cycle) (step S111). The initial value of the travel distance d is 0.

[0082] The control unit 3300 then determines whether the travel distance d is less than or equal to the threshold TH31 (for example, 10m) (step S113). If the travel distance d exceeds the threshold TH31, the control unit 3300 sets the regeneration coefficient to 0 (step S121). Then, the process returns to the calling process.

[0083] On the other hand, if the travel distance d is less than or equal to the threshold TH31, the control unit 3300 determines whether the current vehicle speed V ≥ the reference speed V0 - ΔV (for example, 5 km / h) (step S115). In this embodiment, ΔV is set to a fixed value, but it may also be a predetermined ratio r of the reference speed V0, as in the second embodiment. If the current vehicle speed V is less than the lower limit speed, the control unit 3300 sets the regeneration coefficient to 0 (step S119). Then the process returns to the calling process.

[0084] On the other hand, if the current vehicle speed V is equal to or greater than the lower limit speed, the control unit 3300 sets the regenerative coefficient to (V - (V0 - ΔV)) / ΔV (step S117). That is, it sets the regenerative coefficient according to (current vehicle speed V - lower limit speed). Then, the process returns to the calling process. Step S117 is the same as step S15 in the first embodiment, and variations as shown in Figure 6 may be adopted, or it may be changed curvilinearly.

[0085] In this way, if the distance traveled d from the point when the current vehicle speed V falls below the reference speed V0 is less than or equal to the threshold TH31, regeneration will be performed. However, if the distance traveled d exceeds the threshold TH31, regeneration will not be performed even if the current vehicle speed V is above the lower limit speed but below the reference speed V0. In other words, the regeneration that occurs when the current vehicle speed V falls below the reference speed V0 can be limited to a certain distance, and by preventing regenerative braking from continuing for too long, deceleration can be suppressed.

[0086] [Embodiment 5] In the first to fourth embodiments, regeneration was performed to decelerate to a lower limit speed of reference speed V0-ΔV, but it is also possible to decelerate within a certain range without setting a lower limit speed.

[0087] In this embodiment, as an example, we will describe a case in which regeneration is performed only for a certain period of time after the current vehicle speed V falls below the reference speed V0.

[0088] The control details of this embodiment are the same as those shown in Figure 11 of the third embodiment, but instead of the first regeneration coefficient setting process A shown in Figure 12 of the third embodiment, the first regeneration coefficient setting process B shown in Figure 15 is executed.

[0089] The control unit 3300 determines whether the time t since the current vehicle speed V fell below the reference speed V0 is less than or equal to the threshold TH21 (for example, 3 seconds) (step S131). The initial value of time t is 0. If time t exceeds the threshold TH21, the control unit 3300 sets the regeneration coefficient to 0 (step S137). Then, the process returns to the calling process.

[0090] On the other hand, if time t is less than or equal to the threshold TH21, the control unit 3300 sets the regeneration coefficient to (TH21-t) / TH21 (step S133). That is, the regeneration coefficient is set to decrease linearly with respect to time t. Then, the control unit 3300 increments time t by one control cycle (step S135). Then, the process returns to the calling process.

[0091] The formula in step S133 is merely an example, and it may also be a curve that becomes zero after time TH21 has elapsed. Figure 16 shows an example of the change in the regeneration coefficient [%] over time [s] (or distance [m] in the sixth embodiment). The above formula corresponds to the solid line f. On the other hand, as shown by the thick line g, the regeneration coefficient may be maintained at 100% for a certain period shorter than TH21, and then decrease linearly. Furthermore, as shown by the dotted line h, the regeneration coefficient may be maintained at 100% until time t reaches TH21, and then set to 0 when time t reaches TH21.

[0092] Also, for example, if the current vehicle speed V is initially greater than or equal to the reference speed V0, and after the regeneration coefficient is set to x (0 < x < 1, for example, 0.3) in step S61 of FIG. 11, the current vehicle speed V becomes less than the reference speed V0, the regeneration coefficient may be set to x × (TH21 - t) / TH21. This case corresponds to the solid line e in FIG. 16. That is, when the current vehicle speed V is equal to the reference speed V0, it is x (= 0.3), and as the speed decreases thereafter, the regeneration coefficient gradually decreases, and when the time t reaches TH21, the regeneration coefficient becomes 0.

[0093] In this way, regeneration is performed if the time t from the point when the current vehicle speed V falls below the reference speed V0 is less than or equal to the threshold value TH21, but if the time t exceeds the threshold value TH21, regeneration is automatically stopped. That is, the regeneration caused by the current vehicle speed V falling below the reference speed V0 can be limited for a certain period of time, and by preventing the regeneration braking from continuing for too long, deceleration can be suppressed.

[0094] [Embodiment 6] As in the fifth embodiment, not only when regeneration is stopped at the time TH21 from the point when the current vehicle speed V falls below the reference speed V0, but also when the travel distance d from the point when the current vehicle speed V falls below the reference speed V0 reaches the threshold value TH41, regeneration may be automatically stopped.

[0095] The control content of this embodiment is the same as that of FIG. 13 in the fourth embodiment, but instead of the second regeneration coefficient setting process A shown in FIG. 14 in the fourth embodiment, the second regeneration coefficient setting process B shown in FIG. 17 is executed.

[0096] First, the control unit 3300 updates the travel distance d with the previous travel distance d + (current vehicle speed V × control cycle) (step S141). The initial value of the travel distance d is 0.

[0097] The control unit 3300 then determines whether the travel distance d is less than or equal to the threshold TH41 (for example, 10m) (step S143). If the travel distance d exceeds the threshold TH41, the control unit 3300 sets the regeneration coefficient to 0 (step S147). Then, the process returns to the calling process.

[0098] On the other hand, if the travel distance d is less than or equal to the threshold TH41, the control unit 3300 sets the regenerative coefficient to (TH41-d) / TH41 (step S145). In other words, the regenerative coefficient is set to decrease linearly according to the travel distance d. Then, the process returns to the calling process.

[0099] The formula in step S145 is merely an example; it could also be a curve where the regeneration coefficient becomes zero when the travel distance d reaches the threshold TH41. Alternatively, it could be a straight line as shown in Figure 16. In this case, threshold TH41 is used instead of threshold TH21, and the regeneration coefficient changes according to the travel distance d, not time t.

[0100] In this way, regeneration will be performed if the distance traveled d from the point when the current vehicle speed V falls below the reference speed V0 is less than or equal to the threshold TH41. However, if the distance traveled d exceeds the threshold TH41, regeneration will be automatically stopped. In other words, the regeneration that occurs when the current vehicle speed V falls below the reference speed V0 can be limited to a certain distance, and deceleration can be suppressed by preventing regenerative braking from continuing for too long.

[0101] [Embodiment 7] In the second embodiment, an example was shown in which ΔV, which determines the lower limit speed, is set as a constant ratio r of the reference speed V0. However, ΔV may also be set according to the remaining battery capacity SOC of the battery pack 101. For example, if the remaining battery capacity SOC is large, it is not necessary to increase the remaining battery capacity SOC so a small value is set for ΔV. However, if the remaining battery capacity SOC is small, a large value is set for ΔV in order to increase the amount of charge by regeneration and increase the remaining battery capacity SOC to extend the driving range.

[0102] More specifically, the operation of this embodiment is shown in Figure 18. However, since it is almost the same as Figure 4, only the differences will be explained. The added process is step S29. After it is determined in step S9 that the current vehicle speed V is less than the reference speed V0, the control unit 3300 determines ΔV according to the remaining battery capacity SOC (step S29). Then the process moves on to step S13.

[0103] An example of ΔV set in step S29 will be explained using Figure 19. Figure 19 shows the relationship between the remaining battery capacity (SOC) and the ratio r of ΔV to the reference speed V0, or ΔV itself.

[0104] For example, as shown by the thick line j, if the remaining battery capacity (SOC) is less than 20%, the ratio r of ΔV to the reference speed V0 is set to 30%; if the remaining battery capacity (SOC) exceeds 60%, the ratio r is set to 10%; and if the remaining battery capacity (SOC) is 20% or more but 60% or less, the ratio r increases linearly from 10% to 30% by the amount by which the remaining battery capacity (SOC) falls below 60%. In this way, even when driving at a vehicle speed below the reference speed V0, regeneration can be performed for a longer period when the remaining battery capacity (SOC) is low, and the remaining battery capacity (SOC) can be increased by a greater amount.

[0105] When setting ΔV itself, as shown on the right-hand vertical axis, if the remaining battery capacity SOC is less than 20%, ΔV should be set to 4 km / h; if the remaining battery capacity SOC is greater than 60%, ΔV should be set to 2 km / h; and if the remaining battery capacity SOC is 60% or less but 20% or more, ΔV should increase linearly from 2 km / h to 4 km / h as the remaining battery capacity SOC falls below 60%.

[0106] In this example, the 20% and 60% of the remaining battery capacity (SOC), the 10% and 30% of the ratio r, and the 2km / h and 4km / h of ΔV are merely examples and can be changed as appropriate.

[0107] Furthermore, the changes in the ratio r and ΔV in the interval from 20% to 60% of the battery remaining capacity (SOC) are not limited to a straight line. They may also change in a curved manner. In addition, as shown by the solid line k in Figure 19, when the battery remaining capacity (SOC) falls below 60%, the ratio r or ΔV may be increased once, but there may be an interval in which the ratio r or ΔV does not change even as the battery remaining capacity (SOC) decreases, and then the ratio r or ΔV increases again as the battery remaining capacity (SOC) decreases further. It is also possible to have such an invariant interval. Increasing the ratio r or ΔV too much may result in excessive deceleration, and it may be preferable to increase it to the upper limit only after the battery remaining capacity (SOC) has run out of margin.

[0108] Although embodiments of the present invention have been described above, the present invention is not limited thereto. For example, depending on the purpose, any technical features in each of the embodiments described above may be deleted, or any technical features described in other embodiments may be added.

[0109] Furthermore, the functional block diagram described above is just an example; one functional block can be divided into multiple functional blocks, or multiple functional blocks can be integrated into a single functional block. Similarly, the processing flow can be rearranged or multiple steps executed in parallel, as long as the processing content remains the same.

[0110] Regarding the conditions for setting the reference speed, the above example shows that the relationship between pedal rotation and wheel rotation is predetermined, but it may also be set using other conditions described in the prior art.

[0111] The embodiments described above can be summarized as follows:

[0112] The motor control device according to the first embodiment of the embodiment includes a drive unit that drives or regenerates a motor, and a control unit that sets the vehicle speed when transitioning to a predetermined driving or pedal operation state as a reference speed, and controls the drive unit to generate regenerative torque when the vehicle speed is between the reference speed and a lower limit speed determined based on the reference speed.

[0113] With this configuration, regeneration will occur even when the vehicle speed is between the reference speed and the lower limit speed determined based on that reference speed. For example, regeneration can be automatically performed within an appropriate range even on gentle downhill slopes or flat ground. If the vehicle speed is above the reference speed, regeneration may be performed according to different rules.

[0114] Furthermore, the lower speed limit mentioned above may also be a speed that is a predetermined speed below the standard speed or a predetermined percentage below the standard speed. Compared to cases where the lower speed limit for regeneration is set independently of the standard speed, this allows for a more appropriate range of vehicle speeds in which regeneration occurs. More specifically, if the lower speed limit is set too high in advance, regeneration may not occur even when there is an opportunity for it, depending on the standard speed. Conversely, if the lower speed limit is set too low in advance, depending on the standard speed, excessive regeneration may occur, resulting in excessive deceleration.

[0115] Furthermore, the lower speed limit mentioned above may be determined based on the reference speed and the remaining battery capacity of the battery supplying power to the motor. For example, in order to extend the driving range, the lower speed limit may be lowered when the battery capacity is low to allow for more regeneration.

[0116] Furthermore, the control unit described above may also control the drive unit to generate regenerative torque within a certain time or distance from the moment the vehicle speed falls below the reference speed, and while the vehicle speed is down to the lower limit speed. When regeneration is performed when the vehicle speed is below the reference speed, if regeneration is performed for a long time or distance from the moment the vehicle speed falls below the reference speed, it may decelerate too much. Therefore, by imposing a limit in terms of time or distance, regeneration is limited to an appropriate range.

[0117] Furthermore, the regenerative torque mentioned above may also be a regenerative torque that corresponds to the relationship (e.g., difference) between vehicle speed and minimum speed. In other words, the regenerative torque may be a function of vehicle speed and minimum speed. As mentioned above, the regenerative coefficient may be a function of vehicle speed and minimum speed (e.g., a function of the difference between vehicle speed and minimum speed), and the above regenerative torque may be calculated from the separately calculated target regenerative torque and regenerative coefficient.

[0118] Furthermore, the predetermined driving or pedal operation state described above may also be a state in which the relationship between the motor rotation and the pedal rotation satisfies predetermined conditions. More specifically, if the first value is the vehicle speed (m / s) or wheel rotation speed (rpm) calculated from the wheel rotation, and the second value is the vehicle speed or wheel rotation speed calculated from the pedal rotation, the system may detect a state in which the first value and the second value differ by a predetermined level or more based on the degree of agreement or deviation between the first value and the second value. In addition, the same conditions as in the conventional technology may be adopted to set the reference speed.

[0119] The motor control device according to the second embodiment of the embodiment includes a drive unit that drives or regenerates the motor, and a control unit that sets the vehicle speed when a predetermined driving or pedal operation state is transitioned as a reference speed, and controls the drive unit to generate regenerative torque within a certain time from the timing when the vehicle speed falls below the reference speed or within a certain distance traveled from the timing.

[0120] With this configuration, regeneration will occur within a certain time period or within a certain distance traveled from the moment the vehicle speed falls below the standard speed. This allows for automatic regeneration within an appropriate range, even on gentle downhill slopes or flat ground. If the vehicle speed is above the standard speed, regeneration may be performed according to different rules.

[0121] Furthermore, the control unit described above may be configured to generate regenerative torque according to the elapsed time or distance traveled from the above timing. For example, the regenerative torque may be configured to decrease according to the elapsed time or distance traveled.

[0122] Furthermore, the predetermined driving or pedal operation state described above may also be a state in which the relationship between the motor rotation and the pedal rotation satisfies predetermined conditions. This is the same as in the first embodiment.

[0123] Such configurations are not limited to those described in the embodiments, and may also be implemented in other configurations that produce substantially the same effect.

Claims

1. A motor control device for an electric assist vehicle, comprising a pedal for human power input and a motor driven to assist the input human power, A drive unit that drives or regenerates the motor, A control unit sets the vehicle speed at a predetermined driving or pedal operation state as the reference speed, and controls the drive unit to generate regenerative torque when the vehicle speed is between the reference speed and a lower limit speed determined based on the reference speed. It has, The aforementioned predetermined driving or pedal operation state is: This refers to a state in which the degree of agreement or deviation between a first value, which is the vehicle speed or the number of rotations of the wheels of the electric assist vehicle, calculated from the rotation of the wheels, and a second value, which is the vehicle speed or the number of rotations of the wheels, calculated from the rotation of the pedals, results in the first value and the second value differing by a predetermined level or more. Motor control device.

2. The motor control device according to claim 1, wherein the lower limit speed is a speed that is a predetermined speed below the reference speed or a speed that is a predetermined percentage below the reference speed.

3. The motor control device according to claim 1 or 2, characterized in that the lower limit speed is determined based on the reference speed and the remaining battery capacity of the battery that supplies power to the motor.

4. The control unit, The drive unit is controlled to generate regenerative torque within a certain time period from the moment the vehicle speed falls below the reference speed, or within a certain distance traveled from that moment, and while the vehicle speed is at or below the lower limit speed. The motor control device according to claim 1.

5. The regenerative torque is the regenerative torque corresponding to the relationship between the vehicle speed and the lower limit speed. The motor control device according to claim 1.

6. A motor control device for an electric assist vehicle, comprising a pedal for human power input and a motor driven to assist the input human power, A drive unit that drives or regenerates the motor, A control unit sets the vehicle speed at a predetermined driving or pedal operation state as the reference speed, and controls the drive unit to generate regenerative torque within a certain distance from the moment the vehicle speed falls below the reference speed. It has, The aforementioned predetermined driving or pedal operation state is: This refers to a state in which the degree of agreement or deviation between a first value, which is the vehicle speed or the number of rotations of the wheels of the electric assist vehicle, calculated from the rotation of the wheels, and a second value, which is the vehicle speed or the number of rotations of the wheels, calculated from the rotation of the pedals, results in the first value and the second value differing by a predetermined level or more. Motor control device.

7. The control unit, This generates regenerative torque corresponding to the distance traveled from the aforementioned timing. The motor control device according to claim 6.

8. An electric assist vehicle having a motor control device according to claim 1 or 6.

Images