Saddle-riding vehicle and method for controlling vehicle

Abstract

To bring a feeling felt by a user during traveling operation of a vehicle close to a feeling intended by the user.SOLUTION: A saddle-riding vehicle according to an embodiment includes: a vehicle body; an electric motor mounted on the vehicle body as a driving source and rotatable in normal and reverse directions; and a processing circuit for controlling the electric motor. The processing circuit is configured to: determine whether a control mode is a normal traveling mode in which torque of the electric motor is changed according to acceleration operation by a user or a low-speed mode in which a traveling speed is limited as compared to the normal traveling mode; when determining that the control mode is the low-speed mode, determine whether operation by the user is forward traveling operation or backward traveling operation; when determining that the operation by the user is the forward traveling operation, change a rotation speed or output torque of the electric motor in the normal direction at a first change rate; and when determining that the operation by the user is the backward traveling operation, change the rotation speed or output torque of the electric motor in the reverse direction at a second change rate. An absolute value of the first change rate is greater than an absolute value of the second change rate.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a saddle-ride vehicle and a method for controlling the vehicle. [Background technology]

[0002] Patent Document 1 discloses a vehicle that can move forward and backward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-120597 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a user to be able to operate such a vehicle that can move forward and backward in a way that is closer to the feeling that the user intends.

[0005] Therefore, one aspect of the present disclosure aims to provide a saddle-ride vehicle and a vehicle control method that can easily bring the feeling a user gets when operating the vehicle closer to the feeling the user intends. [Means for solving the problem]

[0006] A saddle-riding vehicle according to one aspect of the present disclosure is a saddle-riding vehicle comprising a vehicle body, an electric motor capable of rotating forward and reverse and mounted on the vehicle body as a drive source, and a processing circuit that controls the electric motor, wherein the processing circuit determines whether the control mode is a normal driving mode in which the torque of the electric motor is changed in response to a user's acceleration operation, or a slow-motion mode in which the driving speed is limited compared to the normal driving mode, and if it determines that the control mode is the slow-motion mode, determines whether the user's operation is a forward operation or a reverse operation, and if it determines that the user's operation is a forward operation, changes the rotation speed or output torque of the electric motor in the forward direction at a first rate of change, and if it determines that the user's operation is a reverse operation, changes the rotation speed or output torque of the electric motor in the reverse direction at a second rate of change, wherein the absolute value of the first rate of change is greater than the absolute value of the second rate of change.

[0007] A saddle-riding vehicle according to another aspect of the present disclosure is a saddle-riding vehicle comprising a vehicle body, an electric motor mounted on the vehicle body as a drive source, and a processing circuit that controls the electric motor, wherein the processing circuit is configured to determine whether the control mode is a normal driving mode or a slow-motion mode, and if it determines that the control mode is the normal driving mode, to perform torque control that controls the electric motor in accordance with correspondence information that indicates the relationship between the user's acceleration operation amount and output torque, and if it determines that the control mode is the slow-motion mode, to perform rotation speed control that causes the actual rotation speed of the electric motor to follow a target rotation speed of the electric motor.

[0008] A vehicle control method according to one embodiment of the present disclosure is a method for controlling a vehicle that includes an electric motor capable of rotating forward and reverse and a processing circuit, wherein the processing circuit determines whether a user's operation is a forward operation or a reverse operation, and if it determines that the user's operation is a forward operation, changes the rotation speed or output torque of the electric motor in the forward direction at a first rate of change, and if it determines that the user's operation is a reverse operation, changes the rotation speed or output torque of the electric motor in the reverse direction at a second rate of change, the absolute value of the first rate of change being greater than the absolute value of the second rate of change. [Effects of the Invention]

[0009] According to the present disclosure, the feeling that the user feels when operating the vehicle can be made closer to the feeling that the user intends. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a vehicle according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of the steering wheel and meter device of the vehicle shown in FIG. 1. [Figure 3] FIG. 2 is a block diagram showing the electrical configuration of the vehicle shown in FIG. [Figure 4] 10 is a table showing the correspondence relationship between the vehicle state, user operation, control mode, and setting value during slow-down control. [Figure 5] 10 is a flowchart showing the flow of a torque command output process. [Figure 6] 10 is a graph showing an example of a change in motor rotation speed over time in a slow-motion mode. [Figure 7] FIG. 4 is a block diagram of the slow rotation speed control unit of FIG. 3. [Figure 8] 8 is a graph for explaining noise removal from the actual rotation speed by the change rate limiting unit and the filter processing unit of FIG. 7. [Figure 9] 8 is a graph for explaining a deviation limiting process by the deviation limiting unit of FIG. 7. [Figure 10] 10 is an example of an offset torque map. [Figure 11] FIG. 4 is a block diagram of the torque limiting unit of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment will be described with reference to the drawings.

[0012] (Vehicle configuration) FIG. 1 is a schematic diagram of a vehicle 1 according to one embodiment. In this embodiment, the vehicle 1 is a saddle-ride type electric two-wheeled vehicle. The vehicle 1 includes a body 2 and a battery pack 3. The battery pack 3 is detachable from the body 2. However, the battery pack 3 does not have to be detachable from the body 2. The body 2 is supported by front wheels 4, which are driven wheels, and rear wheels 5, which are drive wheels. An electric motor 6, which is a driving source for traveling, is supported on the body 2.

[0013] The electric motor 6 generates a driving force that is transmitted to the rear wheels 5, which are the drive wheels. The driving torque generated by the electric motor 6 is transmitted to the rear wheels 5 via a power transmission mechanism 7. The electric motor 6 is capable of rotating in both forward and reverse directions. The electric motor 6 not only functions as a driving source for driving, but also functions as a generator when the vehicle 1 is decelerating, for example. The electric motor 6 is provided with a rotation speed sensor 22 (see FIG. 3) that detects the rotation speed of the output shaft of the electric motor 6. The power transmission mechanism 7 includes a reducer 7a that reduces the rotation speed of the electric motor 6, and a mechanism 7b (for example, a chain transmission mechanism or a belt transmission mechanism) that transmits the rotational power output from the reducer 7a to the axle of the rear wheels 5.

[0014] The vehicle body 2 has a body frame, which has a head pipe 11 and a pair of left and right main frames 12 extending rearward from the head pipe 11. The head pipe 11 rotatably supports a steering shaft 13. A front fork 14 extending substantially vertically is connected to the steering shaft 13, and a front wheel 4 is rotatably supported at the lower end of the front fork 14. A battery case 17 is disposed between the pair of main frames 12 in the left-right direction. The battery case 17 is fixed to the pair of main frames 12. The battery case 17 houses a battery pack 3. A bar-shaped handlebar 15 extending left and right is connected to the upper end of the steering shaft 13. A meter device 18 is disposed in front of the handlebar 15 and is supported by the head pipe 11 via a bracket 16.

[0015] 2 is an enlarged view of the steering wheel 15 and the meter device 18 of the vehicle 1 in FIG. 1 and their vicinity. A torque command operator 15a is disposed on the steering wheel 15, and is operable to cause the electric motor 6 to generate a drive torque. In this embodiment, the torque command operator 15a is the right grip of the steering wheel 15. The torque command operator 15a is rotatable within a predetermined angle range around a central axis C extending in the longitudinal direction.

[0016] The torque command operator 15a is configured to return to a predetermined reference position when no operation is performed by the user (i.e., the driver). The torque command operator 15a can rotate from a predetermined reference position around a central axis C in a first movement direction R1, and can rotate from the reference position around the central axis C in a second movement direction R2 opposite to the first movement direction R1. The torque command operator 15a is biased to the reference position when not operated. When the torque command operator 15a is rotated from the reference position in the first movement direction R1 or the second movement direction R2, the movement direction of the torque command operator 15a and the operation amount from the reference position (hereinafter referred to as the accelerator operation amount) are detected by an accelerator sensor 21 (see FIG. 3).

[0017] A brake lever 19 is disposed in front of the right grip, which is the torque command operator 15a. The brake lever 19 is a torque command operator for operating a front wheel brake mechanism disposed on the front wheel 4. By pulling the brake lever 19 toward you, the front wheel brake mechanism is operated and a mechanical braking force acts on the front wheel 4.

[0018] A mode changeover switch 23 is disposed on the opposite side of the handle 15 in the left-right direction from the side where the torque command operator 15a is located, i.e., on the left side of the handle 15. The mode changeover switch 23 accepts a user's operation for changing the control mode of the controller 31 (described later) between a normal driving mode and a slow-moving mode.

[0019] The normal driving mode is a mode in which the torque of the electric motor 6 is changed in accordance with the amount of operation of the torque command operator 15a by the user. Specifically, in the normal driving mode, the controller 31 increases the output as the amount of operation of the torque command operator 15a in the first movement direction increases. When the torque command operator 15a is rotated from the reference position in the first movement direction R1 in the normal driving mode, the electric motor 6 generates a drive torque corresponding to the amount of operation for rotating the torque command operator 15a from the reference position in the first movement direction R1. The normal driving mode is set as a mode for traveling on a road. For example, in the normal driving mode, if a minimum traveling speed is set for the road, the normal driving mode is set to allow traveling at a speed exceeding the minimum traveling speed.

[0020] The creep mode is a mode in which the maximum traveling speed is limited compared to the normal traveling mode, causing the vehicle 1 to travel at a slower speed. That is, the maximum traveling speed in the creep mode is set lower than that in the normal traveling mode. For example, if the vehicle 1 is equipped with a rotation speed limiter that limits the maximum rotation speed of the electric motor 6, the maximum traveling speed in the normal traveling mode is the traveling speed when the electric motor 6 rotates at the maximum rotation speed limited by the rotation speed limiter in the normal traveling mode, and the maximum traveling speed in the creep mode is set lower than that traveling speed. The creep mode can be used, for example, when parking the vehicle 1 from a traveling road in a bicycle parking lot, or when moving the vehicle from the bicycle parking lot to a traveling road. The creep mode can also be used for turning using reverse steering, moving the vehicle from a stopped state on a slope to a starting position, etc. The maximum traveling speed in the creep mode may be set to approximately walking speed.

[0021] In the creep mode, the vehicle 1 can be moved forward or backward at a slow speed in response to an operation on the torque command operator 15a. For example, when the torque command operator 15a is rotated from the reference position in the first movement direction R1 by a first angle or more in the creep mode, the vehicle 1 moves forward at a slow speed up to the maximum forward speed set in the creep mode. When the torque command operator 15a is rotated from the reference position in the second movement direction R2 by a second angle or more in the creep mode, the vehicle 1 moves backward at a slow speed up to the maximum reverse speed set in the creep mode.

[0022] 2, the meter device 18 displays whether the control mode of the controller 31 is the normal driving mode or the slow driving mode in a distinguishable manner. For example, when the selected control mode is the slow driving mode, the meter device 18 may display a set of information relating to the absolute value of the driving speed and information relating to whether the driving direction of the vehicle 1 is forward or backward. In addition, the meter device 18 may display various other information such as the motor rotation speed and the remaining battery charge.

[0023] (Electrical configuration) FIG. 3 is a block diagram showing the electrical configuration of the vehicle 1 of FIG. 1. A controller 31 and an inverter 32 are fixed to the body 2 of the vehicle 1. In terms of hardware, the controller 31 has a processor, memory, an I / O interface, and the like. The memory includes, for example, storage such as a hard disk or flash memory, and a main memory such as RAM. The storage stores a program for issuing control commands to the electric motor 6. The processor and memory included in the controller 31 are examples of a processing circuit.

[0024] The controller 31 receives accelerator operation amount information indicating the accelerator operation amount detected by the accelerator sensor 21. The accelerator operation amount information detected by the accelerator sensor 21 includes information regarding the direction and amount by which the torque command operator 15a has moved from the reference position due to the user's operation.

[0025] The controller 31 also receives motor rotation speed information indicating the motor rotation speed detected by the rotation speed sensor 22 .

[0026] The controller 31 also receives a mode switching signal from the mode switching switch 23 for switching the control mode from the normal driving mode to the creep mode or from the creep mode to the normal driving mode. The controller 31 switches the control mode between the normal driving mode and the creep mode based on the received mode switching signal. The mode switching switch 23 may transmit the mode switching signal to the controller 31 by being pressed for a long time, or may transmit the mode switching signal to the controller 31 by being pressed for a short time. In this embodiment, when the vehicle 1 is in a stopped state, the user may press the mode switching switch 23 for a predetermined period of time, which causes the mode switching signal to be transmitted from the mode switching switch 23 to the controller 31. In this case, if the current control mode is the normal driving mode, the controller 31 switches to the creep mode. If the current control mode is the creep mode, the controller 31 switches to the normal driving mode.

[0027] When the controller 31 receives a mode switching signal for switching from the normal driving mode to the creep mode, the controller 31 may determine whether a predetermined mode switching condition for switching from the normal driving mode to the creep mode is satisfied, and may switch from the normal driving mode to the creep mode if it determines that the mode switching condition is satisfied. For example, the mode switching condition may include a condition that the vehicle speed is equal to or lower than a predetermined speed. For example, the mode switching condition may include a condition that the motor rotation speed is equal to or lower than a predetermined rotation speed. If the vehicle 1 is equipped with a transmission that changes the gear ratio, for example, the mode switching condition may include a condition that the gear ratio is equal to a predetermined gear ratio.

[0028] The controller 31 also communicates with electronic devices built into the battery pack 3. The battery pack 3 has a battery 3a, a temperature sensor 3b, and a battery management unit (BMU) 3c. The battery 3a is configured by connecting multiple battery cells in series. The temperature sensor 3b detects the temperature of the battery 3a.

[0029] In terms of hardware, the battery management unit 3c has a processor, memory, an I / O interface, etc. The memory includes, for example, storage such as a hard disk or flash memory, and a main memory such as RAM. The memory of the battery management unit 3c stores battery identification information for identifying the battery pack 3, and limit information regarding the limit value of the discharge current of the battery 3a and the limit value of the charge current of the battery 3a.

[0030] Furthermore, the battery management unit 3c estimates the amount of electricity stored in the battery 3a, i.e., the state of charge (SOC) of the battery 3a. For example, the battery pack 3 may include a voltage sensor that detects the voltage value of each battery cell of the battery 3a and a current sensor that detects the charging current to the battery 3a and the discharging current from the battery 3a, and the battery management unit 3c may estimate the charging rate of the battery 3a from the voltage value of each battery cell detected by the voltage sensor and the amount of current being charged and discharged detected by the current sensor.

[0031] The controller 31 receives from the battery pack 3 battery temperature information indicating the temperature of the battery 3a detected by the temperature sensor 3b, and charging rate information (hereinafter also referred to as SOC information) indicating the charging rate of the battery 3a estimated by the battery management unit 3c.

[0032] The controller 31 and the inverter 32 are connected to each other so that they can communicate with each other. Furthermore, the battery 3a is electrically connected to the electric motor 6 via the inverter 32. The controller 31 sends a control command to the inverter 32 to control the inverter 32. The inverter 32 is controlled by the controller 31 to convert DC power discharged from the battery 3a into AC power and supply it to the electric motor 6, and to convert AC power generated by the electric motor 6 using power transmitted from the rear wheels 5, which are the drive wheels, into DC power and supply it to the battery 3a to charge it.

[0033] In terms of functionality, the controller 31 has a normal driving control unit 41, a slow-motion control unit 42, a torque limiting unit 43, etc. The normal driving control unit 41, the slow-motion control unit 42, and the torque limiting unit 43 are realized by the processor performing arithmetic processing on the program read from the storage to the main memory.

[0034] The normal driving control unit 41 controls the electric motor 6 when the control mode of the controller 31 is the normal driving mode. More specifically, the memory of the controller 31 stores correspondence relationship information indicating the correspondence between the accelerator operation amount, the motor rotation speed, and torque. The correspondence relationship information may be, for example, a torque map or an arithmetic expression. The correspondence relationship information may be information indicating the correspondence between at least the accelerator operation amount and the torque. When the control mode of the controller 31 is the normal driving mode, the normal driving control unit 41 refers to the correspondence relationship information to obtain the torque corresponding to the accelerator operation amount indicated by the received accelerator operation amount information and the motor rotation speed indicated by the received motor rotation speed information, and determines the torque as the required torque Tr to be required of the electric motor 6.

[0035] The slow-motion control unit 42 controls the electric motor 6 when the control mode of the controller 31 is the slow-motion mode. The slow-motion control unit 42 includes a vehicle state information acquisition unit 42a, an operation information acquisition unit 42b, a slow-motion rotation speed control unit 42c, and a slow-motion torque control unit 42d.

[0036] The vehicle state information acquisition unit 42a acquires vehicle state information indicating the state of the vehicle 1. The vehicle state information is information that makes it possible to determine whether the vehicle state is a forward state or a reverse state. The vehicle state information acquisition unit 42a acquires the vehicle state information by determining the vehicle state from motor rotation speed information.

[0037] In this embodiment, the vehicle state information acquisition unit 42a determines that the vehicle state is a forward state when the motor rotation speed information indicates that the electric motor 6 is rotating in the forward direction. Furthermore, the vehicle state information acquisition unit 42a determines that the vehicle state is a reverse state when the motor rotation speed information indicates that the electric motor 6 is rotating in the negative direction. In this specification, the positive direction of the electric motor 6 refers to the rotation direction of the electric motor 6 that generates a drive torque that accelerates the vehicle 1 forward, and the negative direction of the electric motor 6 refers to the rotation direction of the electric motor 6 that generates a drive torque that accelerates the vehicle 1 backward. Furthermore, the vehicle state information acquisition unit 42a determines that the vehicle state is a stopped state when the motor rotation speed information indicates that the motor rotation speed is zero.

[0038] The operation information acquisition unit 42b acquires operation information indicating the operation content of the user on the torque command operator 15a in the slow-moving mode. The operation information is information that makes it possible to determine whether the user's operation in the slow-moving mode is a forward operation, a reverse operation, or a reference position operation. The operation information acquisition unit 42b determines whether the user's operation corresponds to a forward operation, a reverse operation, or a reference position operation from the accelerator operation amount information, and acquires the determination result as operation information.

[0039] In this embodiment, when the accelerator operation amount information indicates that the torque command operator 15a is rotated from the reference position by a first angle or more in the first movement direction R1, the operation information acquisition unit 42b determines that the user's operation is a forward operation, which is a first movement operation. Also, when the accelerator operation amount information indicates that the torque command operator 15a is rotated from the reference position by a second angle or more in the second movement direction R2, the operation information acquisition unit 42b determines that the user's operation is a reverse operation, which is a second movement operation.

[0040] Furthermore, when the operation information acquisition unit 42b determines that the user's operation is neither a forward operation nor a reverse operation, it determines that the user's operation is a reference position operation. That is, when the accelerator operation amount information indicates that the position of the torque command operator 15a is at a position that is less than a first angle in the first movement direction R1 from the reference position and less than a second angle in the second movement direction R2 from the reference position, the operation information acquisition unit 42b determines that the user's operation is a reference position operation.

[0041] In addition, since the torque command operator 15a is configured to return to the reference position when the user does not operate the torque command operator 15a, even if the user does not operate the torque command operator 15a, the user's operation is determined to be a reference position operation.

[0042] The creep rotation speed control unit 42c performs rotation speed control in the creep mode to bring the actual rotation speed of the electric motor 6 closer to the target rotation speed. The rotation speed control by the creep rotation speed control unit 42c is selected and performed when a rotation speed control condition is satisfied in the creep mode. For example, the rotation speed control condition is that the vehicle is in a traveling state and the user operation is a forward operation or a reverse operation. The creep rotation speed control unit 42c controls the rotation speed so that the actual rotation speed approaches the target rotation speed. Specifically, the creep rotation speed control unit 42c calculates a torque for bringing the actual rotation speed closer to the target rotation speed based on the deviation between the actual rotation speed and the target rotation speed, and determines this torque as a required torque Tr to be requested of the electric motor 6. The rotation speed control by the creep rotation speed control unit 42c will be described in detail below.

[0043] The creep torque control unit 42d executes a predetermined torque control. The torque control by the creep torque control unit 42d is selected and executed when the torque control conditions are satisfied during the creep mode. As will be described later, when the vehicle is traveling and the user operation is a reference position operation, the torque control conditions are satisfied and the torque control by the creep torque control unit 42d is selected. The creep torque control unit 42d acquires the regenerative torque corresponding to the motor rotation speed indicated by the motor rotation speed information and determines the regenerative torque as the required torque Tr to be requested of the electric motor 6.

[0044] The torque limiting unit 43 executes torque limiting processing to limit the torque required of the electric motor 6 so as not to exceed the upper limit of the discharge current and the upper limit of the charge current of the battery 3a.

[0045] (Control mode and setting values ​​in creep mode) 4 is a table showing the correspondence between vehicle states, user operations, control modes, and setting values ​​in the slow-motion mode. Whether the slow-motion rotation speed control unit 42c executes rotation speed control or the slow-motion torque control unit 42d executes torque control depends on the combination of the vehicle state indicated by the vehicle state information and the user operation indicated by the operation information.

[0046] 4, when the controller 31 determines that the powering control condition is satisfied, the controller 31 executes powering control to cause the electric motor 6 to generate a drive torque for running the vehicle 1. The powering control condition is a condition in which the vehicle state is in a forward drive state and the user's operation is a forward drive operation, or a condition in which the vehicle state is in a reverse drive state and the user's operation is a reverse drive operation. That is, when the controller 31 determines, from the vehicle state information and the operation information, that the vehicle state is in a forward drive state and the user's operation is a forward drive operation, or when the controller 31 determines that the vehicle state is in a reverse drive state and the user's operation is a reverse drive operation, the controller 31 executes the powering control.

[0047] The powering control in the creep mode is one form of rotation speed control by the aforementioned creep rotation speed control unit 42c, and it brings the actual rotation speed of the electric motor 6 closer to the target rotation speed. The target rotation speed during powering control gradually increases from the point when it is determined that the powering control condition is satisfied, while the powering control condition is satisfied, and is maintained at a predetermined speed limit (speed limit) (see also FIG. 6). The speed limit during creeping is set to a value sufficiently smaller than the limit speed set in the normal driving mode. The increase rate and upper speed limit of the target rotation speed do not depend on the amount of operation of the torque command operator 15a by the user, as long as the torque command operator 15a is in a position where it has exceeded a first angle in the first movement direction R1 from the reference position, or where it has exceeded a second angle in the second movement direction R2 from the reference position. In other words, the target rotation speed during powering control in the creep mode is set to change essentially in the same way regardless of whether the amount of operation of the torque command operator 15a is large or small.

[0048] When the slow-motion control unit 42 determines that the first regenerative control condition is satisfied, it executes first regenerative control, which causes the electric motor 6 to generate regenerative torque, which is torque for braking the vehicle 1. The first regenerative control condition is the torque control condition described above, and the first regenerative control in the slow-motion mode is the torque control of the slow-motion torque control unit 42d described above. That is, the first regenerative control condition is a condition in which the vehicle state is in a forward movement state and the user's operation is a reference position operation, or in which the vehicle state is in a reverse movement state and the user's operation is a reference position operation. When the controller 31 determines, from the vehicle state information and the operation information, that the vehicle state is in a forward movement state and the user's operation is a reference position operation, or when the controller 31 determines that the vehicle state is in a reverse movement state and the user's operation is a reference position operation, it executes first regenerative control.

[0049] When the slow-motion control unit 42 determines that the second regenerative control condition is satisfied, it executes second regenerative control, which causes the electric motor 6 to generate regenerative torque, which is torque for braking the vehicle 1. The second regenerative control condition is a condition in which the vehicle state is in a forward movement state and the user's operation is a reverse movement operation, or a condition in which the vehicle state is in a reverse movement state and the user's operation is a forward movement operation. That is, when the controller 31 determines, from the vehicle state information and the operation information, that the vehicle state is in a forward movement state and the user's operation is a reverse movement operation, or when the controller 31 determines that the vehicle state is in a reverse movement state and the user's operation is a forward movement operation, it executes second regenerative control. The second regenerative control in the slow-motion mode is one form of rotation speed control by the slow-motion rotation speed control unit 42c described above.

[0050] The second regenerative control generates a greater regenerative braking force than the first regenerative control. The amount of regeneration (i.e., the amount of regenerative power) achieved by the second regenerative control is greater than the amount of regeneration achieved by the first regenerative control. Furthermore, the amount of regeneration achieved by the second regenerative control when the vehicle is in a forward traveling state differs from the amount of regeneration achieved by the second regenerative control when the vehicle is in a reverse traveling state. The amount of regeneration achieved by the second regenerative control when the vehicle is in a forward traveling state is greater than the amount of regeneration achieved by the second regenerative control when the vehicle is in a reverse traveling state.

[0051] Next, a flow of a torque command output process for outputting a torque command to the electric motor 6 will be described with reference to Fig. 5. In the torque command output process, the controller 31 determines whether or not the current control mode is the slow-motion mode (step S1).

[0052] If it is determined that the current control mode is the creep mode (step S1: Yes), the controller 31 determines whether the torque control condition is satisfied, in other words, whether the conditions that the vehicle is in a traveling state and the user operation is a reference position operation are satisfied (step S2).If it is determined that the torque control condition is satisfied (step S2: Yes), the controller 31 determines the required torque Tr by creep torque control, which is torque control by the creep torque control unit 42d (step S3).

[0053] If it is determined that the torque control condition is not satisfied (step S2: No), the controller 31 determines the required torque Tr through slow rotation speed control, which is rotation speed control by the slow rotation speed control unit 42c (step S4).

[0054] In step S1, if it is determined that the current control mode is not the slow-down mode (step S1: No), the controller 31 determines the required torque Tr by normal torque control, which is torque control by the normal traveling control unit 41 (step S5).

[0055] After determining the required torque Tr in any one of steps S3, S4, and S5, the controller 31 executes torque limiting processing to generate a torque command so that the torque required of the electric motor 6 does not exceed a predetermined upper limit value (step S6), and outputs the generated torque command to the inverter 32 (step S7).

[0056] The controller 31 repeats steps S1 to S7 while the predetermined termination condition is not satisfied (step S8: No). If it is determined that the predetermined termination condition is satisfied (step S8: Yes), the controller 31 ends the torque command output process.

[0057] The control mode in creep mode will be described in more detail with reference to Figure 6. Figure 6 shows the time changes in the target rotation speed and actual rotation speed of the electric motor 6 when the user performs a forward operation and then a reverse operation when the control mode is creep mode. The graph shown by the solid line in Figure 6 is the target rotation speed of the electric motor 6, and the graph shown by the dashed line is the actual rotation speed of the electric motor 6. The horizontal axis represents elapsed time t, and the vertical axis represents the rotation speed.

[0058] When the user starts a forward movement operation while the vehicle 1 is stopped in the creep mode (elapsed time t=t1 in FIG. 6 ), in other words, when the user's operation amount on the torque command operator 15a reaches or exceeds a predetermined value, more specifically, when the torque command operator 15a is rotated from the reference position in the first movement direction R1 by a first angle or more, the controller 31 selects and executes powering control, which is one form of rotation speed control of the creep rotation speed control unit 42c. The powering control in the creep mode is rotation speed control, specifically rotation speed feedback control, that brings the actual rotation speed of the electric motor 6 closer to the target rotation speed. In this embodiment, PID feedback control is used as an example. The controller 31 changes the target rotation speed at a first rate of change α over time until it reaches a predetermined first limit rotation speed Mf_lim. The first rate of change α is the rotational acceleration of the rotation speed of the electric motor 6. The first rate of change α includes a first rate of change α1 for starting and a first rate of change α2 for traveling. The absolute value of the first change rate for starting α1 is greater than the absolute value of the first change rate for running α2.

[0059] The controller 31 changes the target rotation speed at a first starting rate of change over time. While changing the target rotation speed at the first starting rate of change α1, the controller 31 determines whether a first rate of change switching condition is satisfied. The first rate of change switching condition is a condition in which the absolute value of the actual rotation speed of the electric motor 6 exceeds the absolute value of a predetermined threshold Mf_s. When it is determined that the first rate of change switching condition is satisfied (elapsed time t=t2 in FIG. 6), the controller 31 changes the target rotation speed at a first driving rate of change α2 over time. When the target rotation speed reaches the first limit rotation speed Mf_lim (elapsed time t=t3 in FIG. 6), the controller 31 maintains the target rotation speed at the first limit rotation speed Mf_lim. For example, the controller 31 increases the required torque Tr as the deviation between the target rotation speed and the actual rotation speed increases. The controller 31 maintains the required torque Tr at a state in which the deviation between the target rotation speed and the actual rotation speed is zero.

[0060] In this way, whether or not to execute powering control in creep mode is selected depending on whether the amount of operation on the torque command operator 15a is equal to or greater than a predetermined value. As long as the amount of operation on the torque command operator 15a is equal to or greater than the predetermined value, the rate of change of the target rotation speed is set to a constant rate of change α (increase rate) regardless of the magnitude of the amount of operation. The first rotation speed limit Mf_lim is set to a value corresponding to the creep speed of the vehicle. The creep speed is set to a value that is extremely small compared to the maximum forward speed of the vehicle that can be achieved in normal driving mode, for example, 10 km / h or less. In this embodiment, the vehicle speed corresponding to the first rotation speed limit Mf_lim is approximately 5 km / h in the forward direction on a flat road.

[0061] Subsequently, when the user performs a reference position operation to return the torque command operator 15a to the reference position (elapsed time t=t4 in FIG. 6 ), in other words, when the user's operation amount becomes equal to or less than a predetermined value, more specifically, when the torque command operator 15a is rotated from the reference position to a position less than a first angle in the first movement direction R1 and less than a second angle in the second movement direction R2 from the reference position, the controller 31 selects and executes first regenerative control, which is the torque control of the creep torque control unit 42d. In this case, in the creep mode, the controller 31 references the correspondence information stored in the memory, as described below, and executes regenerative torque control, which controls the electric motor 6 to generate regenerative torque corresponding to the received motor rotation speed. The regenerative braking force generated by the first regenerative control decelerates the vehicle 1, and the actual rotation speed of the electric motor 6 decreases. Note that, because torque control, not rotation speed control, is executed between time t4 and time t5 in FIG. 6 , the target rotation speed is not shown by a solid line, but only the actual rotation speed is shown by a dashed line.

[0062] Thereafter, when the user performs a reverse operation during deceleration (elapsed time t=t5 in FIG. 6), controller 31 selects the rotation speed control of slow rotation speed control unit 43c and transitions from first regenerative control to second regenerative control. In second regenerative control, controller 31 sets the target rotation speed to zero and executes feedback control of electric motor 6 so that the rotation speed of electric motor 6 becomes zero. A regenerative braking force greater than that in first regenerative control acts until the actual rotation speed decreases to zero (from time t5 to time t6 in FIG. 6).

[0063] When the actual rotation speed reaches zero during reverse operation (elapsed time t=t6 in FIG. 6), the creep rotation speed control unit 43c continues to select rotation speed control, and transitions from second regenerative control to powering control, which generates drive torque in the negative direction in the electric motor 6. Powering control in creep mode is rotation speed control that brings the actual rotation speed of the electric motor 6 closer to the target rotation speed. The controller 31 changes the target rotation speed at a second rate of change β over time until it reaches a predetermined second limit rotation speed Mr_lim. The second rate of change β is the rotational acceleration of the rotation speed of the electric motor 6. The second rate of change includes a second rate of change β1 for starting and a second rate of change β2 for traveling. The absolute value of the second rate of change β1 for starting is greater than the absolute value of the second rate of change β2 for traveling.

[0064] The controller 31 changes the target rotation speed at a second change rate β1 for starting over time. While changing the target rotation speed at the second change rate β1 for starting, the controller 31 determines whether a second change rate switching condition is satisfied. The second change rate switching condition is a condition in which the absolute value of the actual rotation speed of the motor exceeds the absolute value of a predetermined threshold value Mr_s. If it is determined that the second change rate switching condition is satisfied (elapsed time t=t7 in FIG. 6), the controller 31 changes the target rotation speed at a second change rate β2 for running over time. If the target rotation speed reaches the second limit rotation speed Mr_lim (elapsed time t=t8 in FIG. 6), the controller 31 maintains the target rotation speed at the second limit rotation speed Mr_lim. The second limit rotation speed Mr_lim is set to a value corresponding to the creep speed of the vehicle. The creep speed is set to a value that is extremely small compared to the maximum forward speed of the vehicle that can be achieved in the normal running mode, for example, 10 km / h or less. In this embodiment, the vehicle speed corresponding to the second rotational speed limit Mr_lim is approximately 3 km / h in the reverse direction on a flat road.

[0065] Furthermore, whether the vehicle is in a forward or reverse state, powering control, first regenerative control, or second regenerative control may be performed depending on the user's operation. However, as shown in Figure 4, in this embodiment, even if the control mode is the same, the absolute values ​​of the set values ​​used for various controls may differ depending on whether the vehicle is in a forward or reverse state. For example, the absolute values ​​of the set values ​​of the following parameters (i) to (vii) differ between the rotation speed control performed in a forward state and the rotation speed control performed in a reverse state.

[0066] (i) Absolute value of the rate of change of the target rotation speed (first rate of change α, second rate of change β) (ii) Absolute value of maximum target rotation speed (Mf_lim, Mr_lim) (iii) Absolute value of the threshold for the target rotation speed change rate switching condition (Mf_s, Mr_s) (iv) Absolute value of deviation limit value (Df, Dr) (v) Absolute value of the threshold for switching to high-speed processing (vi) Absolute value of offset torque (vii) Absolute values ​​of upper and lower torque limits

[0067] The absolute values ​​of the change rates of the target rotation speed (first change rate α, second change rate β) in (i) will be explained. In powering control when the vehicle 1 is moving forward, the target rotation speed is changed at the first change rate α over time, and in powering control when the vehicle 1 is moving backward, the target rotation speed is changed at the second change rate β over time. The absolute value of the first change rate α is larger than the absolute value of the second change rate β. For example, the absolute value of the first change rate α1 for starting is larger than the absolute value of the second change rate β1 for starting. For example, the absolute value of the first change rate α2 for traveling is larger than the absolute value of the second change rate β2 for traveling.

[0068] The absolute values ​​(Mf_lim, Mr_lim) of the maximum target rotation speeds in (ii) will be described. In powering control when the vehicle 1 is moving forward, the maximum target rotation speed is limited to the first limit rotation speed Mf_lim, and in powering control when the vehicle 1 is moving backward, the maximum target rotation speed is limited to the second limit rotation speed Mr_lim. The absolute value of the first limit rotation speed Mf_lim is greater than the absolute value of the second limit rotation speed Mr_lim. For example, the first limit rotation speed Mf_lim is a rotation speed set so that the vehicle speed is 5 km / h in the forward direction, and the second limit rotation speed Mr_lim is a rotation speed set so that the vehicle speed is 3 km / h in the backward direction. That is, in the slow-travel mode of this embodiment, the absolute value of the maximum traveling speed is greater in forward travel than in reverse travel. As described above, in this embodiment, the vehicle speed corresponding to the first rotational speed limit Mf_lim is approximately 5 km / h on a flat road, and the vehicle speed corresponding to the second rotational speed limit Mr_lim is approximately 3 km / h on a flat road.

[0069] The absolute values ​​(Mf_s, Mr_s) of the thresholds for the condition for switching the change rate of the target rotation speed in (iii) will now be described. In powering control when the vehicle 1 is moving forward, when the absolute value of the actual rotation speed of the motor exceeds the absolute value of the threshold Mf_s, the first change rate of the target rotation speed is switched from the first change rate for starting α1 to the first change rate for running α2, and in powering control when the vehicle 1 is moving backward, when the absolute value of the actual rotation speed of the motor exceeds the absolute value of the threshold Mr_s, the second change rate of the target rotation speed is switched from the second change rate for starting β1 to the second change rate for running β2. The absolute value of the threshold Mf_s when moving forward is greater than the absolute value of the threshold Mr_s when moving backward.

[0070] The parameters (iv), (v), (vi), and (vii) will be described in detail later.

[0071] (Slow rotation speed control) The rotation speed control process executed by the slow rotation speed control unit 42c will be described with reference to Figures 7 to 10. As shown in Figure 7, the slow rotation speed control unit 42c includes a change rate limiting unit 51, a filter processing unit 52, a data acquiring unit 53, a deviation limiting unit 54, a deviation acquiring unit 55, a PID control unit 56, an offset torque acquiring unit 57, and an adding unit 58.

[0072] The change rate limiting unit 51 and the filter processing unit 52 remove noise from the motor rotation speed detected by the rotation speed sensor 22. Specifically, the change rate limiting unit 51 performs change rate limiting filter processing on the motor rotation speed detected by the rotation speed sensor 22. The change rate limiting filter processing is processing that limits the time rate of change of time series data of the actual rotation speed of the electric motor 6 to within a predetermined range. The filter processing unit 52 performs low-pass filter processing (processing to remove high-frequency components) on the data that has been subjected to the change rate limiting filter processing by the change rate limiting unit 51.

[0073] FIG. 8 is a graph illustrating noise removal from the actual rotation speed by the change rate limiter 51 and filter processor 52 of FIG. 7. The solid line in FIG. 8 represents raw data from the rotation speed sensor 22, showing the change over time in the actual rotation speed of the electric motor 6 detected by the rotation speed sensor 22. In this example, the actual rotation speed gradually increases and is then maintained at a certain rotation speed. At a certain time, a sudden change occurs in the actual rotation speed. This sudden change in the actual rotation speed leads to a sudden change in the required torque Tr, which is the output of the slow rotation speed control unit 42c, and is desirably removed before PID control is performed.

[0074] The dashed line in Fig. 8 shows the results of applying only low-pass filtering to the actual rotation speed data detected by the rotation speed sensor 22. Comparing the dashed line graph with the solid line graph, applying low-pass filtering results in smoothed, noise-free data. However, if processing is performed using only low-pass filtering, the processed data will have a large time lag compared to the sensor data shown in the solid line graph.

[0075] The graph indicated by the dashed dotted line in Fig. 8 shows the results of applying rate-of-change limiting filter processing and low-pass filter processing to the actual rotation speed data detected by the rotation speed sensor 22. The actual rotation speed data detected by the rotation speed sensor 22 is first subjected to rate-of-change limiting filter processing to reduce the amplitude of noise, and then smoothed by low-pass filter processing. Because the amplitude of noise is reduced, excessive filtering can be prevented compared to processing using only low-pass filter processing. As a result, it is also possible to prevent a large time delay from occurring with respect to the sensor data.

[0076] Returning to FIG. 7 , the data acquisition unit 53 acquires target rotation speed data. The target rotation speed data is data relating to how the target rotation speed is changed over time. For example, the target rotation speed data is data for changing the target rotation speed over time to the limit rotation speeds Mf_lim and Mr_lim at preset change rates α and β, and, once the target rotation speed reaches the limit rotation speeds Mf_lim and Mr_lim, changing the target rotation speed so as to maintain the limit rotation speeds Mf_lim and Mr_lim. The target rotation speed data includes information relating to the setting values ​​of the above-mentioned parameters (i), (ii), and (iii). A plurality of target rotation speed data are stored in the memory of the controller 31, and the data acquisition unit 53 selects and acquires one target rotation speed data from the plurality of target rotation speed data based on the vehicle state information and operation information.

[0077] The deviation limiting unit 54 executes deviation limiting processing that limits an increase in the absolute value of the target rotation speed in accordance with the actual rotation speed. The deviation limiting processing is processing that prevents the deviation δ between the target rotation speed and the actual rotation speed of the electric motor 6 from becoming too large. The deviation limiting unit 54 acquires the target rotation speed from the data acquiring unit 53, and acquires the actual rotation speed from which noise has been removed by the change rate limiting unit 51 and the filter processing unit 52. The deviation limiting unit 54 limits the change in the target rotation speed so that the deviation obtained by subtracting the acquired actual rotation speed from the acquired target rotation speed does not exceed a predetermined deviation limit value.

[0078] FIG. 9 is a graph for explaining the deviation limiting process by the deviation limiting unit 54 of FIG. 7. In FIG. 9, the horizontal axis represents time, and the vertical axis represents the rotation speed. The graph shown by the solid line in FIG. 9 represents the change over time of the target rotation speed when the deviation limiting process is executed, and the graph shown by the dashed line represents the change over time of the target rotation speed when the deviation limiting process is executed. For comparison, FIG. 9 also shows the target rotation speed and actual rotation speed when the deviation limiting process is not executed. The graph shown by the dashed line in FIG. 9 represents the change over time of the target rotation speed when the deviation limiting process is not executed, and the graph shown by the dashed line represents the change over time of the target rotation speed when the deviation limiting process is not executed.

[0079] If the deviation limiting process is not executed, during powering control when the vehicle 1 is moving forward in the slow-motion mode, the target rotation speed changes at a first rate of change α over time until it reaches the first limit rotation speed Mf_lim, as shown by the dashed-dotted line in the graph in FIG. 9 . In this situation, if the user operates the brake lever 19 to mechanically brake the vehicle 1, the actual rotation speed does not follow the target rotation speed and remains zero, as shown by the dashed-two-dot line in the graph in FIG. 9 . Therefore, the deviation between the target rotation speed and the actual rotation speed increases. If the user releases the brake operation after the target rotation speed reaches the first limit rotation speed Mf_lim, the deviation between the actual rotation speed and the target rotation speed is large, so the required torque Tr calculated from the deviation becomes excessive, and the actual rotation speed rises sharply and significantly overshoots the first limit rotation speed Mf_lim.

[0080] When the deviation limiting process is executed, the change in the target rotation speed is limited so that the deviation δ between the target rotation speed and the actual rotation speed does not exceed the first deviation limit value Df. That is, as shown in the graph indicated by the solid line in FIG. 9, the deviation δ between the target rotation speed and the actual rotation speed increases, and when the deviation reaches the predetermined first deviation limit value Df, the target rotation speed is maintained at the first deviation limit value Df. When the user releases the brake operation while the target rotation speed is maintained at the first deviation limit value Df, the required torque Tr is calculated from the first deviation limit value Df. As indicated by the dashed line in FIG. 9, because the deviation δ between the target rotation speed and the actual rotation speed is limited to the first deviation limit value Df, it is possible to prevent the actual rotation speed from significantly overshooting the first limit rotation speed Mf_lim.

[0081] While FIG. 9 illustrates an example of deviation limiting processing for rotation speed control executed in a forward traveling state, deviation limiting processing is also executed in rotation speed control executed in a reverse traveling state. However, as described above in (iv), the absolute values ​​of the deviation limiting values ​​are different between the deviation limiting processing in a forward traveling state and the deviation limiting processing in a reverse traveling state. In the deviation limiting processing when the vehicle 1 is in a forward traveling state, the deviation between the target rotation speed and the actual rotation speed is limited to a first deviation limiting value Df, and in the deviation limiting processing when the vehicle 1 is in a reverse traveling state, the deviation between the target rotation speed and the actual rotation speed is limited to a second deviation limiting value Dr. The absolute value of the first deviation limiting value Df when traveling forward is greater than the absolute value of the second deviation limiting value Dr when traveling reverse.

[0082] 7, deviation acquisition unit 55 acquires the target rotation speed whose deviation has been limited by deviation limiting unit 54, and acquires the actual rotation speed from which noise has been removed by change rate limiting unit 51 and filter processing unit 52. Deviation limiting unit 54 subtracts the acquired actual rotation speed from the acquired target rotation speed to acquire the deviation between the target rotation speed and the actual rotation speed.

[0083] The PID control unit 56 performs PID (Proportional-Integral-Differential) processing on the deviation δ obtained by the deviation obtaining unit 55. Specifically, the PID control unit 56 calculates a PID control torque by adding together a value obtained by multiplying the deviation δ by a proportional gain, a value obtained by integrating the deviation δ and multiplying the integral gain, and a value obtained by differentiating the deviation δ and multiplying the differential gain. An adder 58 adds an offset torque obtained by an offset torque obtaining unit 57 to the PID control torque, and determines the result as the required torque Tr.

[0084] When the absolute value of the actual rotation speed significantly overshoots the absolute value of the target rotation speed, the PID control unit 56 executes processing to rapidly reduce the absolute value of the actual rotation speed. Specifically, when the value obtained by subtracting the absolute value of the target rotation speed from the absolute value of the actual rotation speed is less than a threshold value, the PID control unit 56 executes normal PID processing (which may also be referred to as normal rotation speed control), and when it determines that a high-speed processing switching condition is satisfied, the PID control unit 56 switches from the normal PID processing to high-speed PID processing (which may also be referred to as high-speed rotation speed control), which rapidly reduces the absolute value of the actual rotation speed compared to when the normal PID processing is executed. The high-speed processing switching condition is a condition in which the absolute value of the actual rotation speed exceeds the absolute value of the target rotation speed by a difference equal to or greater than the threshold value.

[0085] In this embodiment, the high-speed PID processing is a process of clearing an integral value obtained by integrating the deviation δ. However, the high-speed PID processing is not limited to deleting the integral value, and may be a process that rapidly reduces the absolute value of the actual rotation speed compared to normal PID processing. For example, the high-speed PID processing may increase the proportional gain or decrease the integral gain compared to normal PID processing. The high-speed PID processing may reduce, by a predetermined torque, the value obtained by multiplying the deviation δ by the proportional gain, the value obtained by multiplying the deviation δ obtained by integrating the deviation δ by the integral gain, or the value obtained by differentiating the deviation δ by the derivative gain, to obtain the PID control torque.

[0086] In this way, when the high-speed processing condition, that is, the absolute value of the actual rotation speed exceeds the absolute value of the target rotation speed by a difference equal to or greater than the threshold value, is met, normal PID processing is switched to high-speed PID control, but as described above in (v), the absolute value of the threshold value of the high-speed processing switching condition differs when the vehicle 1 is moving forward and when the vehicle 1 is moving backward. The absolute value of the first threshold value of the high-speed processing switching condition for powering control when the vehicle 1 is moving forward is greater than the absolute value of the second threshold value of the high-speed processing switching condition for powering control when the vehicle 1 is moving backward.

[0087] The offset torque acquisition unit 57 acquires the offset torque. The offset torque is a torque that is added to the PID control torque in order to improve the running responsiveness of the vehicle 1 when the motor rotation speed is low, such as when the vehicle 1 starts moving. The offset torque is obtained by referring to an offset torque map that is pre-stored in memory. The offset torque map indicates the correspondence relationship between the motor rotation speed and torque.

[0088] Fig. 10 is an example of an offset torque map. In Fig. 10, the horizontal axis represents the absolute value of the actual rotation speed of the electric motor 6, and the vertical axis represents the absolute value of the offset torque. The graph shown by the solid line in Fig. 10 is a first offset torque map used in rotation speed control when the vehicle 1 is in a forward moving state, and the graph shown by the dashed line in Fig. 10 is a second offset torque map used in rotation speed control when the vehicle 1 is in a forward moving state.

[0089] In both the first offset torque map and the second offset torque map, the absolute value of the torque increases stepwise as the absolute value of the actual rotation speed decreases. The offset torque corresponding to a motor rotation speed above a certain value is zero.

[0090] As described above in (vi), the offset torque differs between the rotation speed control performed in the forward traveling state and the rotation speed control performed in the reverse traveling state. That is, the value of the offset torque relative to the absolute value of the actual rotation speed differs between the first offset torque map and the second offset torque map. The absolute value of the first offset torque obtained by referring to the first offset torque map when the vehicle 1 is in the forward traveling state is greater than the absolute value of the second offset torque obtained by referring to the second offset torque map when the vehicle 1 is in the reverse traveling state.

[0091] Returning to FIG. 7, the adder 58 adds the offset torque to the PID control torque to obtain the required torque Tr, which is then sent to the torque limiter 43.

[0092] (Creep torque control) Next, the torque control process executed by the creep torque control unit 42d will be described. As shown in FIG. 7, the creep torque control unit 42d includes a torque determination unit 59. The torque determination unit 59 acquires a regenerative torque corresponding to the motor rotation speed detected by the rotation speed sensor 22. Specifically, correspondence relationship information indicating the correspondence relationship between the motor rotation speed and the torque is stored in the memory of the controller 31. The correspondence relationship information may be, for example, a torque map or an arithmetic expression. The correspondence relationship information may be information indicating the correspondence relationship between at least the motor rotation speed and the torque (i.e., the regenerative torque). For example, the correspondence relationship information may indicate the correspondence relationship between the accelerator operation amount, the motor rotation speed, and the torque. The creep torque control unit 42d and the normal driving control unit 41 may refer to the same or different correspondence relationship information (e.g., a torque map). The torque determination unit 59 acquires a regenerative torque corresponding to the motor rotation speed indicated by the received motor rotation speed information by referring to the correspondence relationship information, and determines the acquired torque as the required torque Tr to be requested of the electric motor 6. The required torque Tr determined by the torque determination unit 59 is sent to the torque limiting unit 43 .

[0093] (torque limit processing) The torque limiting process by the torque limiting unit 43 will be described with reference to Fig. 11. Fig. 11 is a block diagram of the torque limiting unit 43 in Fig. 3. The torque limiting unit 43 includes a limited current obtaining unit 61, a limited torque calculating unit 62, and a comparing unit 63.

[0094] The limit current acquisition unit 61 determines the limit current based on the battery temperature information received from the temperature sensor 3b and the SOC information received from the battery management unit 3c. Correspondence information indicating the correspondence between the battery temperature and SOC and the charge current limit value Ic and discharge current limit value Id is stored in the memory of the controller 31. The limit current acquisition unit 61 references the correspondence information to acquire the charge current limit value Ic and discharge current limit value Id corresponding to the received battery temperature and SOC. The charge current limit value Ic is the maximum allowable charge current for the received battery temperature and SOC, and the discharge current limit value Id is the maximum allowable discharge current for the received battery temperature and SOC.

[0095] The limit torque calculation unit 62 calculates the charge limit torque Tc from the charge current limit value Ic acquired by the limit current acquisition unit 61. Specifically, the limit torque calculation unit 62 multiplies the charge current limit value Ic by the voltage of the battery 3a to calculate the charge limit power, and then divides the calculated charge limit power by the actual rotation speed of the electric motor 6 to obtain the charge limit torque Tc. By keeping the regenerative torque generated in the electric motor 6 during regenerative control equal to or less than the charge limit torque Tc, the charging current to the battery 3a is kept equal to or less than the charge current limit value Ic. The charge limit torque Tc may also be referred to as the regenerative limit torque Tc. In other words, the regenerative limit torque Tc is the torque when the current flowing into the battery 3a is the maximum allowable charging current.

[0096] The limit torque calculation unit 62 calculates the discharge limit torque Td from the discharge current limit value Id acquired by the limit current acquisition unit 61. Specifically, the limit torque calculation unit 62 calculates the discharge limit power by multiplying the discharge current limit value Id by the voltage of the battery 3a, and then obtains the discharge limit torque Td by dividing the calculated discharge limit power by the actual rotation speed of the electric motor 6. By setting the drive torque generated in the electric motor 6 during powering control to be equal to or less than the discharge limit torque Td, the discharge current from the battery 3a is kept equal to or less than the discharge current limit value Id. The discharge limit torque Td may also be referred to as the powering limit torque Td. In other words, the powering limit torque Td is the torque at which the current flowing from the battery 3a becomes the maximum allowable discharge current.

[0097] In this way, the powering limit torque Td and the regeneration limit torque Tc are changed based on battery state information relating to the state of the battery 3a, i.e., battery temperature information and SOC information. For example, the powering limit torque Td and the regeneration limit torque Tc may be set to be smaller as the temperature of the battery 3a increases. For example, the regeneration limit torque Tc is set to be smaller as the SOC approaches 100%. This is to avoid overcharging the battery 3a. Furthermore, in this embodiment, under the same SOC and battery temperature conditions, the powering limit torque Td is greater than the regeneration limit torque Tc.

[0098] The comparison unit 63 compares the required torque Tr determined by the creep rotation speed control unit 42c or the creep torque control unit 42d with the limit torque calculated by the limit torque calculation unit 62. That is, the comparison unit 63 compares the required torque Tr with the powering limit torque Td during powering control, and compares the required torque Tr with the regenerative limit torque Tc during first regenerative control or second regenerative control. If the comparison unit 63 determines that the absolute value of the required torque Tr does not exceed the absolute value of the limit torque, it outputs a control command to the inverter 32 to cause the electric motor 6 to generate the required torque Tr. If the comparison unit 63 determines that the absolute value of the required torque Tr exceeds the absolute value of the limit torque, it outputs a control command to the inverter 32 to cause the electric motor 6 to generate the limit torque.

[0099] The comparison unit 63 limits the torque in the positive or negative direction required of the electric motor 6 during powering control to equal to or less than the powering limit torque Td. Furthermore, the comparison unit 63 limits the torque in the positive or negative direction required of the electric motor 6 during regenerative control to equal to or less than the regenerative limit torque Tc. Therefore, as described above in (vii), the absolute values ​​of the upper limit torque, which is the limit torque in the positive direction of the electric motor 6, and the lower limit torque, which is the limit torque in the negative direction of the electric motor 6, differ between the rotation speed control performed in the forward drive state and the rotation speed control performed in the reverse drive state.

[0100] Specifically, the comparison unit 63 acquires the powering limit torque Td and the regenerative limit torque Tc calculated by the limit torque calculation unit 62. When the comparison unit 63 determines that the vehicle state is a forward movement state, it sets the acquired powering limit torque Td as the upper limit torque and sets the acquired regenerative limit torque Tc as the lower limit torque. In other words, when the vehicle state is a forward movement state, the comparison unit 63 limits the magnitude of the driving torque generated by the electric motor 6 in the forward direction so that it does not exceed the powering limit torque Td, and also limits the magnitude of the regenerative torque generated by the electric motor 6 in the negative direction so that it does not exceed the regenerative limit torque Tc.

[0101] On the other hand, when the comparison unit 63 determines that the vehicle state is reverse, it sets the acquired regenerative limit torque Tc as the upper limit torque and sets the acquired power running limit torque Td as the lower limit torque. In other words, when the vehicle state is reverse, the comparison unit 63 limits the magnitude of the regenerative torque generated by the electric motor 6 in the forward direction so that it does not exceed the regenerative limit torque Tc, and limits the magnitude of the drive torque generated by the electric motor 6 in the negative direction so that it does not exceed the power running limit torque Td.

[0102] However, in this embodiment, as an exception, the comparison unit 63 determines whether the vehicle state is a predetermined very slow speed traveling state, and if it determines that the vehicle state is a very slow speed traveling state, executes a torque limit relaxation process that relaxes the limit on the required regenerative torque Tr compared to when it is determined that the vehicle state is not a very slow speed traveling state. In other words, the comparison unit 63 sets the regenerative limit torque Tc that is set when it is determined that the vehicle state is a very slow speed traveling state larger than the regenerative limit torque Tc calculated by the limit torque calculation unit 62 that is set when it is determined that the vehicle state is not a very slow speed traveling state.

[0103] For example, the slow speed state is a state in which the amount of regeneration by the electric motor 6 is equal to or less than a predetermined value. The slow speed state may also be a state in which the absolute value of the motor rotation speed is equal to or less than a predetermined value. The slow speed state includes a stopped state of the vehicle 1 in which the absolute value of the motor rotation speed is zero.

[0104] The reason why the limit on the required regenerative torque Tr is relaxed when the vehicle is traveling at a very slow speed in this embodiment will be explained. For example, when the battery 3a is fully charged, the regenerative limit torque Tc calculated by the limit torque calculation unit 62 is zero or almost zero to prevent overcharging. Assume that the battery 3a is fully charged and the vehicle 1 is moving forward at a very slow speed (for example, a speed of 1 km or less). Assume that the user operates the vehicle in reverse in this state. In this case, since the vehicle 1 is moving forward, the limit torque in the negative direction of the electric motor 6 is zero or almost zero of the regenerative limit torque. Therefore, even if the user operates the vehicle in reverse, no torque is generated in the negative direction of the electric motor 6. On the other hand, when the vehicle 1 is traveling at an extremely slow speed, the amount of regeneration is almost zero. Therefore, when the vehicle 1 is traveling at a very slow speed at which no regenerative torque is generated, the battery will not be overcharged even if no limit is placed on the regenerative torque of the electric motor 6. This is the reason why the limit on the required regenerative torque Tr is relaxed when the vehicle is traveling at a very slow speed.

[0105] Specifically, the comparison unit 63 determines whether the vehicle state is a very slow speed state based on the rotation speed detected by the rotation speed sensor 22. When the comparison unit 63 determines that the vehicle 1 is in a very slow speed state, the comparison unit 63 sets the magnitude of the regenerative limit torque Tc to the same magnitude as the powering limit torque Td calculated by the limit torque calculation unit 62, instead of setting it to the regenerative limit torque Tc calculated by the limit torque calculation unit 62 based on the SOC and battery temperature. In other words, both the upper limit torque and the lower limit torque are set to the powering limit torque Td. This relaxes the restriction on the regenerative torque. This is because even when the battery 3a is fully charged, the powering limit torque Td is not zero or nearly zero like the regenerative limit torque Tc, but is a relatively large value.

[0106] However, in the process of relaxing the limit on the regenerative torque, instead of setting the magnitude of the regenerative limit torque Tc to the same magnitude as the powering limit torque Td calculated by the limit torque calculation unit 62, the regenerative limit torque Tc may not be set, or may be set to a predetermined torque greater than the regenerative limit torque Tc calculated by the limit torque calculation unit 62.

[0107] (Action and effect) As described above, according to this embodiment, the controller 31 changes the target rotation speed over time at the first rate of change α during powering control when the vehicle 1 is moving forward, and changes the target rotation speed over time at the second rate of change β during powering control when the vehicle 1 is moving backward. The absolute value of the first rate of change α is greater than the absolute value of the second rate of change β. Therefore, in the slow-travel mode, the vehicle can travel in a manner appropriate for both moving forward and moving backward.

[0108] For example, when the vehicle is moving forward in slow-motion mode, the absolute value of the rate of change of the electric motor's rotation speed or output torque can be made larger than when the vehicle is moving backward in slow-motion mode, making it easier to drive in accordance with the driver's intended feeling. Specifically, even in slow-motion mode, when the vehicle is moving forward, the driver can operate the controls while looking ahead, so a relatively high acceleration operation is desired even in slow-motion mode.

[0109] In addition, when the vehicle is moving backward in slow-motion mode, the area in which the rear can be seen is smaller than when the vehicle is moving forward. In this embodiment, the absolute value of the rate of change of the rotation speed or output torque of the electric motor 6 is made smaller when the vehicle is moving backward in slow-motion mode than when the vehicle is moving forward, making it easier to avoid obstacles and stop the vehicle when traveling backward.

[0110] That is, in the slow-motion mode, the speed increase during forward travel can be accelerated to improve operability, and the speed increase during reverse travel can be suppressed to facilitate the avoidance of obstacles.

[0111] Furthermore, according to this embodiment, when the control mode is the creep mode, the controller 31 executes rotation speed control to control the actual rotation speed of the electric motor 6 based on the target rotation speed of the electric motor 6, making it easy to adjust the traveling speed of the vehicle in the creep mode. Specifically, by executing the rotation speed control, it is possible to prevent torque fluctuations in the vehicle 1 and make it easy to adjust the traveling speed.

[0112] Furthermore, according to this embodiment, when the controller 31 determines that the user's operation is a forward operation, it changes the target rotation speed to the first limit rotation speed Mf_lim and maintains the target rotation speed at the first limit rotation speed Mf_lim, and when the controller 31 determines that the user's operation is a reverse operation, it changes the target rotation speed to the second limit rotation speed Mr_lim and maintains the target rotation speed at the second limit rotation speed Mr_lim. Therefore, when the control mode is the creep mode, the user does not need to perform complicated adjustment operations to maintain the motor rotation speed at the predetermined limit rotation speed. This improves the operability of the vehicle.

[0113] Furthermore, according to this embodiment, the absolute value of the first rotational speed limit Mf_lim is greater than the absolute value of the second rotational speed limit Mr_lim. Therefore, in the slow-travel mode, the vehicle can travel in a manner appropriate for both forward and reverse travel. That is, in the slow-travel mode, the maximum forward speed can be increased to improve operability, and the maximum reverse speed can be reduced to facilitate greater obstacle avoidance.

[0114] Furthermore, according to this embodiment, the offset torques stored are a first offset torque used when it is determined that the user's operation is a forward operation, and a second offset torque used when it is determined that the user's operation is a reverse operation, and the absolute value of the first offset torque is greater than the absolute value of the second offset torque. Therefore, when the user's operation is a reverse operation, the acceleration of the vehicle 1 in the reverse direction can be suppressed. That is, in the slow-travel mode, the increase in speed when traveling forward can be accelerated to improve operability, and the increase in speed when traveling backward can be suppressed to make it easier to avoid obstacles.

[0115] Furthermore, according to this embodiment, a deviation limiting process is executed to limit the change in the target rotation speed so that the deviation between the target rotation speed and the actual rotation speed does not exceed a predetermined deviation limit value. Therefore, when the actual rotation speed does not follow the target rotation speed, which changes over time, the deviation between the target rotation speed and the actual rotation speed can be prevented from becoming too large. For example, when the user applies the brakes, the actual rotation speed does not follow the target rotation speed even if it changes over time. In such a case, the deviation between the target rotation speed and the actual rotation speed can be prevented from becoming too large, thereby suppressing the acceleration of the vehicle when the brakes are released.

[0116] Furthermore, according to this embodiment, a change rate limiting filter process is performed on the motor rotation speed detected by the rotation speed sensor 22, and the time change rate of the time series data of the motor rotation speed is limited to within a predetermined range. This makes it possible to remove noise that may occur in the actual rotation speed, making it easier to control the rotation speed.

[0117] Furthermore, according to this embodiment, when the absolute value of the actual rotation speed exceeds the absolute value of the target rotation speed by a difference equal to or greater than a threshold value, normal PID processing is switched to high-speed PID processing, which reduces the absolute value of the actual rotation speed more rapidly than when normal PID processing is executed. As a result, when the actual rotation speed significantly overshoots the target rotation speed, the absolute value of the actual rotation speed is rapidly reduced, thereby preventing the torque generated by the electric motor 6 from becoming excessive in the creep mode.

[0118] <Other embodiments> The present disclosure is not limited to the above-described embodiments, and the configurations thereof can be changed, added, or deleted.

[0119] For example, while the vehicle described in the above embodiment is an electric vehicle equipped with one drive source, the vehicle is not limited to this. The present disclosure is applicable to any vehicle equipped with a drive source for forward and reverse travel. For example, the vehicle may be a hybrid vehicle equipped with two drive sources, an electric motor and an internal combustion engine. As long as the vehicle has a motor for forward and reverse travel, it may also have a separate drive source. Furthermore, the saddle-ride vehicle does not have to be a two-wheeled vehicle, but may be a three-wheeled vehicle. Furthermore, the vehicle does not have to be a saddle-ride vehicle, but may be, for example, a four-wheeled vehicle. The vehicle may be equipped with a transmission that switches the gear ratio. The vehicle may be equipped with a transmission that can switch the reduction ratio. The vehicle may also be equipped with an operator that accepts gear shift operations by the user.

[0120] In the above embodiment, mode switching between the normal driving mode and the slow-moving mode is performed in response to the operation of the mode selector switch, but this is not limiting. That is, mode switching may be performed in response to predetermined mode switching conditions. For example, instead of using a dedicated mode selector switch, mode switching may be performed when it is determined that multiple existing switches are operated simultaneously. Furthermore, the conditions for switching from the normal driving mode to the slow-moving mode may be different from the conditions for switching from the slow-moving mode to the normal driving mode.

[0121] In the above embodiment, the forward operation or reverse operation by the user in the slow travel mode is performed on the torque command operator 15a, but the forward operation or reverse operation in the slow travel mode may be performed on a torque command operator other than the torque command operator 15a. An operator for the forward operation and an operator for the reverse operation may be provided separately.

[0122] Furthermore, the operation information indicating the user's operation may include information on whether the normal driving mode or the slow-travel mode is selected as the control mode. In other words, the user's operation of moving the vehicle forward or backward may also serve as the operation for selecting the slow-travel mode.

[0123] For example, the vehicle may be equipped with a slow-forward button and a slow-reverse button, and pressing the slow-forward button may be a forward operation in slow-travel mode, and pressing the slow-reverse button may be a reverse operation in slow-travel mode. For example, the vehicle may be equipped with a lever for slow-travel operation, and the lever for slow-travel operation may be used to perform a forward operation or a reverse operation in slow-travel mode. In this case, the lever for slow-travel operation may be configured to be tiltable forward and backward from a reference position, and tilting it forward may be a forward operation, and tilting it backward may be a reverse operation. The lever for slow-travel operation may be configured to be movable in an L-shape.

[0124] In the above embodiment, the absolute values ​​of the set values ​​of the parameters (i) to (vii) were different between the control executed in the forward state and the control executed in the reverse state, but the absolute values ​​of the set values ​​of some of these parameters may be the same between the control executed in the forward state and the control executed in the reverse state. For example, in the above embodiment, the starting change rates α1 and β1 and the traveling change rates α2 and β2 were set, but it is also possible to simply set the change rates α and β for forward and reverse without distinguishing between them. Also, some of the parameters (i) to (vii) may not be set, and the absolute values ​​of the set values ​​of other parameters may be different between the control executed in the forward state and the control executed in the reverse state.

[0125] In the normal driving mode, it is sufficient that the output can be changed in response to the torque command operator 15a, and the torque, driving speed, or motor rotation speed may be changed. For example, in the normal driving mode, instead of executing the torque control described in the above embodiment in which the required torque is determined based on the correspondence relationship information indicating the correspondence relationship between the accelerator operation amount and the torque, feedback control may be executed to bring the actual vehicle speed closer to the target vehicle speed, or feedback control may be executed to bring the actual motor rotation speed closer to the target motor rotation speed.

[0126] In the normal traveling mode, if the vehicle 1 is operated to move backward while stopped, that is, if the torque command operator 15a is rotated from the reference position in the second moving direction R2 by the second angle or more, the vehicle 1 does not have to move backward. Also, in the normal traveling mode, if the vehicle 1 is operated to move backward while traveling forward, that is, if the torque command operator 15a is rotated from the reference position in the second moving direction R2 by the second angle or more, a regenerative braking force may be generated in the electric motor 6, as in the second regenerative control in the creep mode described below.

[0127] In the creep mode, the driving speed may be suppressed compared to the normal driving mode, and the torque, driving speed, or motor rotation speed may be limited. For example, in the creep mode, instead of the feedback control described in the above embodiment that brings the actual motor rotation speed closer to the target motor rotation speed, feedback control that brings the actual vehicle speed closer to the target vehicle speed may be executed, or control that gradually changes the output torque of the electric motor 6 may be executed.

[0128] For example, the controller 31 may be configured to change the output torque of the electric motor in the forward direction at a first rate of change when it determines that the user's operation is a forward operation, and to change the output torque of the electric motor in the reverse direction at a second rate of change when it determines that the user's operation is a reverse operation. In this case, the absolute value of the first rate of change may be greater than the absolute value of the second rate of change.

[0129] The present disclosure is also applicable to vehicles that do not have a creep mode as a control mode. The present disclosure is also applicable to vehicles that can move forward or backward in response to user operation. The controller 31 may have a control mode other than the modes described in the above embodiment.

[0130] In a vehicle capable of traveling forward and backward, a control mode of a controller may be a driving mode in which the vehicle acceleration in the forward direction when a user's operation is determined to be a forward operation is different from the vehicle acceleration in the reverse direction when a user's operation is determined to be a reverse operation. In this case, the absolute value of the vehicle acceleration in the forward direction may be set to be greater than the absolute value of the vehicle acceleration in the reverse direction.

[0131] In the above embodiment, when the vehicle is in a forward or reverse state and the user's operation is a reference position operation in the slow-travel mode, torque control is performed using correspondence information indicating the correspondence between the motor rotation speed and torque. However, in this case, rotation speed control may be performed instead of the torque control. That is, the first regenerative control may be rotation speed control. In other words, even in the case of a reference position operation while traveling in the slow-travel mode, the slow-travel rotation speed control unit 42c may perform rotation speed control so that the target rotation speed gradually decreases at a predetermined third change rate γ. In this case, the change rate may be different between forward and reverse travel.

[0132] Furthermore, the control methods for the first regenerative control and the second regenerative control are not limited to those described in the above embodiment. The amount of regeneration by the second regenerative control only needs to be greater than the amount of regeneration by the first regenerative control. For example, in the above embodiment, the second regenerative control sets the target rotation speed to zero, but the target rotation speed may be reduced to approach zero at a predetermined rate of change. In this case, the first regenerative control may reduce the target rotation speed to approach zero at a rate of change whose absolute value is smaller than the rate of change by the second regenerative control.

[0133] In the above embodiment, even if the control mode is the same, the absolute values ​​of the set values ​​of the above parameters (i) to (vii) differ depending on whether the vehicle is in a forward or reverse state. However, the absolute values ​​of one or more of the set values ​​of the above parameters (i) to (vii) may be the same in both the forward and reverse states.

[0134] The present disclosure is also applicable to a system that does not execute processing related to some of the above parameters (i) to (vii).

[0135] For example, in the rotation speed control in the slow-motion mode in the above embodiment, a change rate limiting filter process is applied to the time series data of the actual rotation speed of the electric motor 6, but it is also possible to apply only a low-pass filter process to the time series data of the actual rotation speed of the electric motor 6 without applying the change rate limiting filter process.

[0136] For example, in the rotation speed control during slow-motion mode in the above embodiment, a deviation limiting process was performed to limit the change in the target rotation speed so that the deviation between the target rotation speed and the actual rotation speed does not exceed a predetermined deviation limit value, but the deviation limiting process does not have to be performed.

[0137] For example, in the rotation speed control in the slow-motion mode in the above embodiment, if the absolute value of the actual rotation speed exceeds the absolute value of the target rotation speed by a difference equal to or greater than a threshold value, the normal PID processing is switched to high-speed PID processing, which rapidly reduces the absolute value of the actual rotation speed compared to when the normal PID processing is executed, but there may be no need to switch between the normal PID processing and the high-speed PID processing.

[0138] In the above embodiment, the controller 31 acquires motor rotation speed information indicating the motor rotation speed from the rotation speed sensor 22 that detects the rotation speed of the output shaft of the electric motor 6. However, the method of acquiring the motor rotation speed information is not limited to this. For example, the vehicle may be equipped with a wheel speed sensor that detects the rotation speed of the drive wheels, and the controller 31 may calculate the rotation speed of the electric motor 6 from the wheel speed information received from the wheel speed sensor. Furthermore, although the vehicle state information acquisition unit 42a determines whether the vehicle state is forward or reverse based on the motor rotation speed information, it may also determine this based on the detection value of the wheel speed sensor. There may be situations in which the vehicle is moving forward or backward due to inertia or on a slope while the electric motor 6 is stopped. Even in such situations, the accuracy of determining the vehicle state is improved by determining the vehicle state using the detection value of the wheel speed sensor.

[0139] In the above embodiment, PID feedback control is used for the rotation speed control, but other known feedback control methods may be used. While torque is used as the controlled variable, rotation speed control may be performed using another control target, such as battery current. Feedback control is preferred, but feedforward control may be used to vary the rate of change of the motor rotation speed or output torque during forward and reverse travel. In cases where the current generated by the torque command is smaller than the allowable current, the torque limiting function may be omitted.

[0140] In the above embodiment, the comparison unit 63 determines whether the vehicle state is a predetermined slow-speed traveling state, and if it determines that the vehicle state is a slow-speed traveling state, the restriction on the required regenerative torque Tr is relaxed compared to when it determines that the vehicle state is not a slow-speed traveling state. However, the controller 31 does not have to perform exception processing in such a slow-speed traveling state.

[0141] That is, regeneration may be prohibited even when the vehicle is traveling at a very low speed. A regeneration prohibition condition that prohibits regeneration may be set to protect the battery. Whether the regeneration prohibition condition is satisfied may be determined based on, for example, the SOC or the battery temperature. The regeneration prohibition condition may include a condition that the SOC is equal to or greater than a predetermined value, or a condition that the battery temperature is equal to or greater than a predetermined temperature. When a regeneration command is given to the controller by a user operation, the controller may determine whether the regeneration prohibition condition is satisfied, and if the regeneration prohibition condition is satisfied, the regeneration command may be invalidated. For example, if the SOC is close to 100% or the battery temperature is within a predetermined regeneration prohibition temperature range, the regeneration command may be invalidated.

[0142] The torque limit relaxation process that relaxes the limit on the required regenerative torque Tr when the vehicle state is a predetermined slow-speed traveling state may be used only for control of moving the vehicle forward or only for control of moving the vehicle backward. Specifically, when the controller determines that the vehicle state is one of a slow-speed traveling state in the forward direction and a slow-speed traveling state in the reverse direction, the controller may execute the torque limit relaxation process that relaxes the limit on the required regenerative torque compared to when the vehicle state is determined not to be the slow-speed traveling state, and may not execute the torque limit relaxation process when the controller determines that the vehicle state is the other slow-speed traveling state. The process of relaxing the limit on the required regenerative torque Tr when the vehicle state is a predetermined slow-speed traveling state may also be applied to vehicles that are not traveling backward.

[0143] In the above embodiment, the amount of regeneration by the second regenerative control is greater than the amount of regeneration by the first regenerative control regardless of whether the vehicle is in a forward or reverse state, but the amount of regeneration by the second regenerative control may be greater than the amount of regeneration by the first regenerative control only when the vehicle is in either a forward or reverse state. When the vehicle is in either a forward or reverse state, it is not necessary to execute either the first or second regenerative control.

[0144] In the above embodiment, when the vehicle is determined to be in a forward or reverse drive mode, the regeneration amount is set to a constant amount regardless of the amount of operation of the torque command operator. However, this is not limiting. For example, the regeneration amount may be increased as the amount of operation of the torque command operator increases.

[0145] The meter device 18 may display information indicating that the vehicle is in a regenerative control state where regenerative control is being executed. In this case, the controller 31 sends a command to the meter device 18 to display that the vehicle is in a regenerative control state. Furthermore, when displaying that the vehicle is in a regenerative control state, the meter device 18 may display information in different ways depending on whether the regenerative braking is strong or weak. In this case, the controller 31 sends information to the meter device 18 indicating whether the regenerative braking is strong or weak.

[0146] The meter device 18 may display information indicating that the control mode is the slow-motion mode. In this case, the controller 31 sends a command to the meter device 18 to display that the control mode is the slow-motion mode. Furthermore, when displaying that the control mode is the slow-motion mode, the meter device 18 may also display in a manner that makes it possible to distinguish whether the vehicle is in a forward or reverse motion. In this case, the controller 31 sends vehicle state information to the meter device 18. Furthermore, the meter device 18 may also display in a manner that makes it possible to distinguish whether the user's operation is a forward motion operation or a reverse motion operation. In this case, the controller 31 sends to the meter device 18 operation information that indicates the content of the user's operation on the torque command operator 15a.

[0147] Each of the above control sections 41 to 43 may be realized by a separate circuit. Alternatively, the controller may read out a program corresponding to the operation of each control section to realize the function of each control section.

[0148] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, or any combination thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware or processor.

[0149] A program containing instructions for performing the methods disclosed herein may be stored on a non-transitory computer-readable storage medium, including, for example, a magnetic disk such as a hard disk drive, an optical disk such as a CD-ROM, a DVD disk, or a Blu-ray disk, a read-only memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic card, a flash memory, an optical card, or any type of medium suitable for storing electronic instructions.

[0150] [Disclosure mode] Each of the following aspects is a disclosure of a preferred embodiment.

[0151] [Aspect 1] The car body and an electric motor capable of rotating forward and backward and mounted on the vehicle body as a drive source; a processing circuit for controlling the electric motor, The processing circuitry determining whether the control mode is a normal driving mode in which the torque of the electric motor is changed in response to an acceleration operation by a user, or a creep mode in which the driving speed is limited compared to the normal driving mode; If it is determined that the control mode is the slow-motion mode, it is determined whether the user's operation is a forward operation or a reverse operation; When it is determined that the user's operation is a forward operation, the rotation speed or output torque of the electric motor in the forward direction is changed at a first change rate; When it is determined that the user's operation is a reverse operation, the rotation speed or output torque of the electric motor in the reverse direction is changed at a second change rate; A saddle-ride vehicle, wherein the absolute value of the first rate of change is greater than the absolute value of the second rate of change. The first rate of change and the second rate of change may be either the rate of change when the absolute value of the rotation speed of the electric motor or the absolute value of the output torque is increased, i.e., an increase rate, or the rate of change when the absolute value of the rotation speed of the electric motor or the absolute value of the output torque is decreased, i.e., a decrease rate, but are preferably the increase rate.

[0152] According to the above configuration, in the slow-travel mode, the vehicle can be driven in a manner appropriate for both forward and reverse travel. For example, when the vehicle is moving forward in the slow-travel mode, the absolute value of the rate of change of the electric motor's rotation speed or output torque can be increased compared to when the vehicle is moving backward in the slow-travel mode, making it easier to drive in accordance with the driver's intentions. When the vehicle is moving backward in the slow-travel mode, the absolute value of the rate of change of the electric motor's rotation speed or output torque can be decreased compared to when the vehicle is moving forward in the slow-travel mode, making it easier to avoid obstacles and stop the vehicle. Therefore, the feeling the user gets when operating the vehicle can be made closer to the feeling the user intends.

[0153] [Aspect 2] The saddle-riding vehicle of aspect 1, wherein the processing circuit is configured to, when determining that the control mode is the slow-motion mode, perform rotation speed control to bring the actual rotation speed of the electric motor closer to the target rotation speed of the electric motor.

[0154] According to the above configuration, the rotational speed of the motor is controlled in the slow-motion mode, so that the traveling speed of the vehicle can be easily adjusted in the slow-motion mode.

[0155] [Aspect 3] The processing circuitry When it is determined that the user's operation is a forward operation, the target rotation speed is changed over time based on the first change rate until it reaches a predetermined first limit value, and when the target rotation speed reaches the first limit value, the target rotation speed is maintained at the first limit value; A saddle riding vehicle as described in aspect 2, configured such that when it is determined that the user's operation is a reverse operation, the target rotation speed is changed over time based on the second change rate until it reaches a predetermined second limit value, and when the target rotation speed reaches the second limit value, the target rotation speed is maintained at the second limit value.

[0156] According to the above configuration, when the control mode is the slow-motion mode, the user does not need to perform an operation to adjust the rotation speed of the motor, thereby improving the operability of the vehicle.

[0157] [Aspect 4] 4. The saddle riding vehicle according to aspect 3, wherein the absolute value of the first rotation speed limit is greater than the absolute value of the second rotation speed limit.

[0158] [Aspect 5] the processing circuit is configured to, when determining that the absolute value of the actual rotation speed is less than a predetermined set value, output a value obtained by adding an offset torque to a torque corresponding to the target rotation speed as a required torque to the electric motor; 3. The saddle riding vehicle according to aspect 2, wherein the absolute value of the offset torque increases as the absolute value of the actual rotation speed decreases.

[0159] According to the above configuration, it is possible to improve the driving responsiveness of the vehicle 1 when the motor rotation speed is low, such as when the vehicle starts moving, and to improve the operability of the vehicle.

[0160] [Aspect 6] the processing circuit stores, as the offset torque, a first offset torque that is used when it is determined that the user's operation is a forward operation, and a second offset torque that is used when it is determined that the user's operation is a reverse operation; and 6. The saddle-ride vehicle according to aspect 5, wherein the absolute value of the second offset torque is smaller than the absolute value of the first offset torque.

[0161] According to the above configuration, since the absolute value of the second offset torque is smaller than the absolute value of the first offset torque, it is possible to suppress the acceleration of the vehicle in the backward direction when the user performs an operation to move the vehicle in reverse.

[0162] [Aspect 7] A saddle riding vehicle as described in any one of aspects 1 to 6, wherein the processing circuit is configured to limit a change in the target rotation speed of the electric motor so that a deviation between the target rotation speed of the electric motor and the actual rotation speed of the electric motor does not exceed a predetermined deviation limit value.

[0163] According to this configuration, when the actual rotation speed does not follow the target rotation speed which changes over time, it is possible to prevent the deviation between the target rotation speed and the actual rotation speed from becoming too large.

[0164] [Aspect 8] the processing circuit stores, as the deviation limit value, a first deviation limit value to be used when it is determined that the user's operation is a forward movement operation, and a second deviation limit value to be used when it is determined that the user's operation is a reverse movement operation; 8. The saddle riding vehicle according to aspect 7, wherein the absolute value of the first deviation limit value is greater than the absolute value of the second deviation limit value.

[0165] According to the above configuration, the regenerative torque decreases over time after it is determined that the regenerative reduction condition is met, thereby reducing the shock that occurs to the vehicle body compared to when the regenerative torque is suddenly reduced.

[0166] [Aspect 9] The processing circuitry applying a filter to the actual rotation speed to limit a rate of change to a predetermined upper limit value; 3. The saddle riding vehicle according to aspect 2, wherein the rotation speed control is performed using the rotation speed after application of the filter.

[0167] According to the above configuration, noise that may occur in the actual rotation speed can be removed, making it easier to control the rotation speed.

[0168] [Aspect 10] The processing circuitry When a value obtained by subtracting the absolute value of the target rotation speed from the absolute value of the actual rotation speed is less than a threshold value, the rotation speed control is performed in a normal mode; A saddle riding vehicle according to aspect 2, configured to switch to a high-speed mode of rotation speed control in which the absolute value of the actual rotation speed is rapidly reduced compared to when the rotation speed control is performed in the normal mode, when the absolute value of the actual rotation speed exceeds the absolute value of the target rotation speed by a difference equal to or greater than the threshold value.

[0169] [Aspect 11] the processing circuit stores, as the threshold values, a first threshold value to be used when the user's operation is determined to be a forward operation, and a second threshold value to be used when the user's operation is determined to be a reverse operation; 11. The saddle riding vehicle according to aspect 10, wherein the absolute value of the first threshold value is greater than the absolute value of the second threshold value.

[0170] [Aspect 12] The car body and an electric motor mounted on the vehicle body as a drive source; a processing circuit for controlling the electric motor, The processing circuitry Determine whether the control mode is a normal driving mode or a slow-down mode; When it is determined that the control mode is the normal running mode, torque control is performed to control the electric motor in accordance with correspondence information indicating a relationship between an acceleration operation amount by a user and an output torque. a straddle-ride vehicle configured to execute a rotation speed control for causing an actual rotation speed of the electric motor to follow a target rotation speed of the electric motor when it is determined that the control mode is the slow-motion mode;

[0171] [Aspect 13] 1. A method for controlling a vehicle having a reversible electric motor and a processing circuit, the processing circuit comprising: Determine whether the user's operation is a forward operation or a backward operation; When it is determined that the user's operation is a forward operation, the rotation speed or output torque of the electric motor in the forward direction is changed at a first change rate; When it is determined that the user's operation is a reverse operation, the rotation speed or output torque of the electric motor in the reverse direction is changed at a second change rate; A vehicle control method, wherein the absolute value of the first rate of change is greater than the absolute value of the second rate of change. [Explanation of symbols]

[0172] 1: Vehicle 2: Body 3: Battery pack 3a: Battery 3b: Temperature sensor 3c: Battery Management Unit 4: Front wheel 5: Rear wheel 6: Electric motor 15a: Torque command operator 21: Accelerator sensor 22: Rotational speed sensor 23: Mode switch 31: Controller

Claims

1. The car body and an electric motor capable of rotating forward and backward and mounted on the vehicle body as a drive source; A saddle riding vehicle including a processing circuit for controlling the electric motor, The processing circuitry includes: determining whether the control mode is a normal driving mode in which the torque of the electric motor is changed in response to an acceleration operation by a user, or a slow driving mode in which the driving speed is limited as compared to the normal driving mode; When it is determined that the control mode is the slow-motion mode, it is determined whether the user's operation is a forward operation or a reverse operation; When the user's operation is determined to be a forward operation, the rotation speed or output torque of the electric motor in a forward direction is changed at a first change rate; When it is determined that the user's operation is a reverse operation, the rotation speed or the output torque of the electric motor in the reverse direction is changed at a second change rate, A saddle riding vehicle, wherein an absolute value of the first rate of change is greater than an absolute value of the second rate of change.

2. The saddle riding vehicle according to claim 1 , wherein the processing circuit is configured to execute a rotation speed control for bringing an actual rotation speed of the electric motor closer to a target rotation speed of the electric motor when the control mode is determined to be the creep mode.

3. The processing circuitry includes: When it is determined that the user's operation is a forward operation, the target rotation speed is changed over time based on the first change rate until it reaches a predetermined first limit rotation speed, and when the target rotation speed reaches the first limit rotation speed, the target rotation speed is maintained at the first limit rotation speed; 3. The saddle riding vehicle according to claim 2, wherein when it is determined that the user's operation is a reverse operation, the target rotation speed is changed over time based on the second change rate until it reaches a predetermined second limit rotation speed, and when the target rotation speed reaches the second limit rotation speed, the target rotation speed is maintained at the second limit rotation speed.

4. The saddle riding vehicle according to claim 3 , wherein an absolute value of the first rotational speed limit is greater than an absolute value of the second rotational speed limit.

5. the processing circuit is configured to, when determining that the absolute value of the actual rotation speed is less than a predetermined set value, output, to the electric motor, a value obtained by adding an offset torque to a torque corresponding to the target rotation speed, as a required torque; The saddle riding vehicle according to claim 2 , wherein the absolute value of the offset torque increases as the absolute value of the actual rotation speed decreases.

6. the processing circuit stores, as the offset torque, a first offset torque to be used when the user's operation is determined to be a forward movement operation, and a second offset torque to be used when the user's operation is determined to be a reverse movement operation; The saddle riding vehicle according to claim 5 , wherein an absolute value of the first offset torque is greater than an absolute value of the second offset torque.

7. 3. The saddle riding vehicle according to claim 2, wherein the processing circuit is configured to limit a change in the target rotation speed of the electric motor so that a deviation between the target rotation speed of the electric motor and an actual rotation speed of the electric motor does not exceed a predetermined deviation limit value.

8. the processing circuit stores, as the deviation limit value, a first deviation limit value to be used when it is determined that the user's operation is a forward movement operation, and a second deviation limit value to be used when it is determined that the user's operation is a reverse movement operation; The saddle riding vehicle according to claim 7 , wherein an absolute value of the first deviation limit value is greater than an absolute value of the second deviation limit value.

9. The processing circuitry includes: applying a filter to the actual rotation speed to limit a rate of change to a predetermined upper limit value; The saddle riding vehicle according to claim 2 , wherein the rotation speed control is performed using the rotation speed after application of the filter.

10. The processing circuitry includes: When a value obtained by subtracting the absolute value of the target rotation speed from the absolute value of the actual rotation speed is less than a threshold value, a normal rotation speed control is executed; 3. The saddle riding vehicle according to claim 2, wherein when the absolute value of the actual rotation speed exceeds the absolute value of the target rotation speed by a difference equal to or greater than the threshold value, the control is switched to a high speed rotation speed control that rapidly reduces the absolute value of the actual rotation speed compared to when the normal rotation speed control is executed.

11. the processing circuit stores, as the threshold value, a first threshold value used when the user's operation is determined to be a forward movement operation, and a second threshold value used when the user's operation is determined to be a reverse movement operation; The saddle riding vehicle according to claim 10 , wherein an absolute value of the first threshold value is greater than an absolute value of the second threshold value.

12. The car body and an electric motor mounted on the vehicle body as a drive source; A saddle riding vehicle including a processing circuit for controlling the electric motor, The processing circuitry includes: Determine whether the control mode is a normal driving mode or a slow-moving mode; When it is determined that the control mode is the normal driving mode, a torque control is executed to control the electric motor in accordance with correspondence information indicating a relationship between an acceleration operation amount by a user and an output torque. a straddle-type vehicle configured to execute a rotation speed control for causing an actual rotation speed of the electric motor to follow a target rotation speed of the electric motor when the control mode is determined to be the creep mode;

13. 1. A method for controlling a vehicle having a reversible electric motor and a processing circuit, the processing circuit comprising: Determine whether the user's operation is a forward operation or a backward operation; When the user's operation is determined to be a forward operation, the rotation speed or output torque of the electric motor in a forward direction is changed at a first change rate; When it is determined that the user's operation is a reverse operation, the rotation speed or output torque of the electric motor in the reverse direction is changed at a second change rate; A method for controlling a vehicle, wherein an absolute value of the first rate of change is greater than an absolute value of the second rate of change.

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