Vehicle control device, vehicle control method, and program

Abstract

To improve operability at the time of start of a saddle-ride type vehicle.SOLUTION: A vehicle control device includes: a torque setting unit (112) which set target torque of a motor according to an accelerator operation amount when the brake operation is released and a saddle-ride type vehicle starts in a state where the saddle-ride type vehicle is stopped and both the brake and the accelerator are simultaneously operated; a torque control unit (114) which gradually increases the torque of the motor so as to reach the set target torque when a predetermined starting time elapses after the saddle-ride type vehicle has started; and a time adjustment unit (113) which changes the length of the starting time according to the rotation speed of the motor during the starting time.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a program.

Background Art

[0002] In recent years, in a saddle-riding type electric vehicle that travels using an electric motor as a drive source, various measures have been taken to improve driving safety. For example, in an electric scooter, there is known an accidental start prevention device that makes it impossible to start even if the throttle is operated when the brake is not operating (see, for example, Patent Document 1). Also, in a given country or region, there is a rule regarding power control that a vehicle must be equipped with a device that automatically cuts off the power supply to the electric motor when the brake is applied.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When starting a saddle-riding type vehicle designed in accordance with the above rules regarding power control, when the driver releases the brake (brake off) from a state where the driver is applying the brake (brake on) and operating the accelerator (accelerator on), there is a moment when neither braking force nor driving force acts on the vehicle. As a result, when starting on an uphill slope, if the accelerator opening is too small, the vehicle may slip backward. On the other hand, if the accelerator opening is too large, a driving force suddenly acts at the moment of brake off, and the driver feels a sudden acceleration and the ride quality deteriorates.

[0005] The embodiments of the present application have been made in view of the above points, and an object thereof is to provide a vehicle control device, a vehicle control method, and a program that can improve the operability when starting a straddle-type vehicle.

Means for Solving the Problems

[0006] The vehicle control device, vehicle control method, and program according to this invention employ the following configurations. (1) A vehicle control device according to one aspect of the present invention sets a target torque of a motor (5) according to an operation amount of an accelerator (2) when an operation of a brake (3) is released and a straddle-type vehicle (1) starts moving in a state where the straddle-type vehicle (1) is stopped and the brake (3) and the accelerator (2) are operated simultaneously. The vehicle control device includes a torque setting unit (112), a torque control unit (114) that gradually increases the torque of the motor (5) so as to reach the set target torque when a predetermined initial movement time elapses after the straddle-type vehicle (1) starts moving, and a time adjustment unit (113) that changes the length of the initial movement time according to the rotational speed of the motor (5) during the initial movement time.

[0007] (2) In the vehicle control device according to the aspect (1) above, when the rotational speed of the motor (5) during the initial movement time is negative when the rotational speed of the motor (5) when the straddle-type vehicle (1) moves forward is set as positive, the time adjustment unit (113) shortens the initial movement time.

[0008] (3) In the vehicle control device according to the aspect (1) or (2) above, when the increase rate of the rotational speed of the motor (5) during the initial movement time is equal to or greater than a predetermined threshold value, the time adjustment unit (113) extends the initial movement time.

[0009] Aspect (4) is a vehicle control device according to any one of aspects (1) to (3) above, further comprising a notification unit (116) that notifies an operation amount of the accelerator (2) according to at least one of a gradient of the saddle-riding type vehicle (1) and a weight of an occupant of the saddle-riding type vehicle (1).

[0010] (5) Another aspect of the vehicle control method of the present invention is that when the computer is in a state where the saddle-riding type vehicle (1) is stopped and the brake (3) and the accelerator (2) are operated simultaneously, and when the operation of the brake (3) is released and the saddle-riding type vehicle (1) starts, a target torque of the motor (5) is set according to the operation amount of the accelerator (2), and after a predetermined starting time has elapsed after the saddle-riding type vehicle (1) has started, the torque of the motor (5) is gradually increased so as to reach the set target torque, and the length of the starting time is changed according to the rotational speed of the motor (5) during the starting time.

[0011] (6) Another aspect of the program of the present invention is to cause the computer to set a target torque of the motor (5) according to the operation amount of the accelerator (2) when the saddle-riding type vehicle (1) is stopped and the brake (3) and the accelerator (2) are operated simultaneously, and when the operation of the brake (3) is released and the saddle-riding type vehicle (1) starts, and after a predetermined starting time has elapsed after the saddle-riding type vehicle (1) has started, the torque of the motor (5) is gradually increased so as to reach the set target torque, and the length of the starting time is changed according to the rotational speed of the motor (5) during the starting time.

Advantages of the Invention

[0012] According to the configurations (1) to (6) described above, the operability at the start of the saddle-riding type vehicle can be improved. Further, according to the configuration of (2) described above, when the torque is insufficient when the brake is released, the torque can be increased promptly, so that, for example, it is possible to prevent the vehicle from sliding down significantly on a slope. Further, according to the configuration of (3) described above, when more torque than necessary is output during braking-off, the torque can be gradually increased up to the target torque, so that a sudden acceleration feeling can be suppressed. Also, according to the configuration of (4) described above, the occupant can grasp an appropriate accelerator operation amount.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0014] A vehicle control device, a vehicle control method, and a program according to an embodiment of the present application will be described with reference to the drawings.

[0015] <Configuration of the Whole Vehicle> FIG. 1 shows a scooter-type motorcycle 1 as an example of a straddle-type vehicle according to an embodiment. In FIG. 1, the X-axis indicates the vehicle length direction, the Y-axis indicates the vehicle height direction, and the Z-axis indicates the vehicle width direction. The motorcycle 1 includes a front wheel that is a steering wheel and a rear wheel that is a drive wheel. The front wheel is supported by a front fork and can be steered by a bar handle (steering handle). A grip portion 2 and a brake 3 are provided on both the left and right sides of the bar handle. A rider (driver) can generate a driving force for the motorcycle 1 by operating, for example, a throttle grip (accelerator 2) provided on the right grip portion 2. Further, the rider can generate a braking force for the motorcycle 1 by operating at least one of the left and right brakes 3.

[0016] The rear wheel is supported at the rear end portion of a swing arm 7 and can be driven by a motor 5 (electric motor) that generates a driving force for traveling of the motorcycle 1 and a speed reduction mechanism 6 that reduces the driving force of the motor 5. The motor 5 is driven by electric power supplied from a battery 4. The motor 5 is arranged with its drive shaft along the vehicle width direction. The motor 5 includes a rotor that rotates integrally with the drive shaft and a stator that surrounds the outer periphery of the rotor and is fixed to a unit case (both are not shown). The motor 5 is, for example, variably speed-driven by VVVF (variable voltage variable frequency) control. The motor 5 is speed-controlled as if it has a continuously variable transmission, but is not limited thereto. The motor 5 may be speed-controlled as if it has a stepped transmission.

[0017] The speed reduction mechanism 6 includes a small-diameter gear that is rotatably provided integrally with the drive shaft of the motor 5 and a large-diameter gear that meshes with the small-diameter gear (both are not shown). The large-diameter gear is rotatably provided integrally with an output shaft that is arranged parallel to the motor drive shaft behind the motor drive shaft. One axial end portion (for example, the left end portion) of the output shaft protrudes outside the unit case, and the protruding portion and the rear wheel are connected so that power can be transmitted through a transmission device using, for example, an endless belt or chain. Note that the output shaft of the motor may be directly connected to the rotation shaft of the rear wheel so that power can be transmitted without a belt or chain.

[0018] The battery 4 is mounted below the seat. The battery 4 includes a plurality (for example, two front and rear in the X-axis direction) of unit batteries 4a and 4b. The plurality of unit batteries 4a and 4b have the same configuration as each other. The unit batteries 4a and 4b are inclined parallel to each other and are arranged at regular intervals along the X-axis direction. The battery 4 generates a predetermined high voltage by connecting the unit batteries 4a and 4b in series. The unit batteries 4a and 4b are each configured as an energy storage capable of charge and discharge, for example, a lithium ion battery.

[0019] A PCU (Power control unit) 10, which is a control unit, is provided in the body main body of the motorcycle 1. The PCU 10 has a flat rectangular parallelepiped outer shape with a reduced vertical width. The PCU 10 performs control for supplying the electric power supplied from the battery 4 to the motor 5 and control for driving the motor 5 according to the operation amount (throttle opening) of the throttle 2.

[0020] <Configuration of Vehicle Control Device> FIG. 2 is a functional block diagram of a vehicle control device 100 according to an embodiment. The vehicle control device 100 is, for example, an ECU (Electric Control Unit). The vehicle control device 100 and a PDU (Power Driver Unit) 200 constitute a PCU 10 which is an integrated control unit. The PDU 200 includes an inverter that converts the direct current supplied from the battery 4 into an alternating current and supplies it to the motor 5. The PDU 200 controls the energization of the stator winding of the motor 5. The motor 5 performs a power running operation according to the control by the PDU 200 and runs the motorcycle 1. The operation of the PDU 200 is controlled by the vehicle control device 100.

[0021] The vehicle control device 100 includes, for example, a control unit 110 and a storage unit 120. The control unit 110 includes, for example, an acquisition unit 111, a torque setting unit 112, a time adjustment unit 113, a torque control unit 114, a power supply control unit 115, and a notification unit 116. Each functional unit included in the control unit 110 is realized, for example, by a hardware processor (computer) such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including a circuit unit; circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by the cooperation of software and hardware. The program may be stored in advance in the storage unit 120 (a storage device having a non-transitory storage medium), or may be stored in a removable storage medium such as a DVD or a CD-ROM, and may be installed in the storage unit 120 by mounting the storage medium (non-transitory storage medium) on a drive device.

[0022] The acquisition unit 111 acquires detection signals from, for example, each of a brake sensor 20, an accelerator sensor 30, a rotation speed sensor 40, a gradient sensor 50, and a weight sensor 60. The acquisition unit 111 acquires a detection signal of the operation of the brake 3 by the occupant from the brake sensor 20 (front brake sensor, rear brake sensor). The brake sensor 20 is, for example, a hydraulic pressure sensor or a stroke sensor or the like. Further, the acquisition unit 111 acquires a detection signal of the operation of the accelerator 2 by the occupant from the accelerator sensor (accelerator position sensor) 30. The accelerator sensor 30 is, for example, a magnetic sensor using a contactless Hall element or the like. Further, the acquisition unit 111 acquires a detection signal of a state quantity (rotation speed of the motor 5) related to the speed of the motorcycle 1 from the rotation speed sensor 40. The rotation speed sensor 40 is, for example, a rotation speed sensor of the motor 5.

[0023] Further, the acquisition unit 111 acquires a detection signal of the inclination of the motorcycle 1 from the inclination sensor 50. The inclination sensor 50 is, for example, a gyroscope provided on the vehicle body. Further, the acquisition unit 111 acquires a detection signal of the weight of the occupant of the motorcycle 1 and the weight of the luggage mounted on the motorcycle 1 from the weight sensor 60. The weight sensor 60 is, for example, a load cell provided below the seat.

[0024] The torque setting unit 112 sets the torque generated in the motor 5 based on the acquired detection signal of the accelerator sensor 30 and the torque reference information TD (torque map) stored in the storage unit 120 in advance. The torque reference information TD defines in advance the relationship between the operation amount of the accelerator (accelerator opening) and the torque generated in the motor 5. Further, when the occupant releases the brake (brake off) and starts (performs the initial movement operation) from the state where the occupant applies the brake (brake on) and operates the accelerator (accelerator on), the torque setting unit 112 is based on the acquired detection signal of the accelerator sensor 30 and the torque reference information TD stored in the storage unit 120 in advance, and sets the torque (target torque) generated in the motor 5 when a predetermined initial movement time (for example, 100 ms) has elapsed after the brake is released.

[0025] The torque setting unit 112 is an example of the "torque setting unit". That is, when the saddle-riding type vehicle (1) is stopped and the brake (3) and the accelerator (2) are simultaneously operated, and then the operation of the brake (3) is released and the saddle-riding type vehicle (1) starts, the torque setting unit 112 sets the target torque of the motor (5) according to the operation amount of the accelerator (2).

[0026] The starting time adjustment unit 113 adjusts the length of the starting time according to the detected signal (motor rotation speed) of the rotation speed sensor 40 acquired within the starting time. During the starting time, the starting time adjustment unit 113 determines the positive or negative of the motor rotation speed indicated by the detected signal of the rotation speed sensor 40 acquired. When the motor rotation speed is negative, the starting time adjustment unit 113 shortens the length of the starting time. On the other hand, during the starting time, the starting time adjustment unit 113 determines the increase rate (increase rate per unit time) of the motor rotation speed indicated by the detected signal of the rotation speed sensor 40 acquired (determines whether it is greater than a threshold value). When the increase rate of the motor rotation speed is large (when it is greater than the threshold value), the starting time adjustment unit 113 extends the length of the starting time.

[0027] The starting time adjustment unit 113 is an example of the "starting time adjustment unit". That is, the starting time adjustment unit 113 changes the length of the starting time according to the rotation speed of the motor (5) during the starting time. Also, when the rotation speed of the motor during the starting time is negative when the straddle-type vehicle (1) is moving forward and the rotation speed of the motor is set as positive, the starting time adjustment unit 113 shortens the starting time. Further, when the increase rate of the rotation speed of the motor during the starting time is equal to or greater than a predetermined threshold value, the starting time adjustment unit (113) extends the starting time.

[0028] The torque control unit 114 performs control to generate a torque corresponding to the set torque (target torque) on the motor 5. After starting when braking is off from the state of braking on and accelerator on, the torque control unit 114 gradually increases the torque and performs torque control of the motor 5 so that the torque generated on the motor 5 reaches the target torque when a predetermined starting time elapses. For example, the torque control unit 114 gradually increases the torque every unit time (for example, 10 ms).

[0029] The torque control unit 114 is an example of the "torque control unit". That is, after the straddle-type vehicle (1) starts, when a predetermined starting time elapses, the torque control unit 114 gradually increases the torque of the motor (5) so as to reach the set target torque.

[0030] The power control unit 115 controls the PDU 200 and controls the power supplied from the battery 4 to the motor 5. Further, the power control unit 115 performs control so as to cut off the power supply from the battery 4 to the motor 5 in a state where the brake is on and the accelerator is on.

[0031] The notification unit 116 notifies the occupant of an appropriate accelerator operation amount based on the detected signal of the acquired slope sensor 50 and the detected signal of the weight sensor 60, and the accelerator operation amount reference information AD stored in the storage unit 120 in advance. The accelerator operation amount reference information AD defines in advance the relationship between the slope and the weight and the appropriate accelerator operation amount. The notification unit 116 notifies the occupant, for example, by displaying an appropriate accelerator opening degree on a display device or the like disposed at a position visible to the occupant in front of the motorcycle 1.

[0032] The notification unit 116 is an example of the "notification unit". That is, the notification unit 116 notifies the operation amount of the accelerator according to at least one of the slope of the saddle-riding type vehicle (1) and the weight of the occupant of the saddle-riding type vehicle (1).

[0033] The storage unit 120 is realized by, for example, an HDD (Hard Disk Drive), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a ROM (Read Only Memory), or a RAM (Random Access Memory). The storage unit 120 stores, for example, torque reference information TD, accelerator operation amount reference information AD, programs, and various other information.

[0034] <Processing flow> Next, the processing of the vehicle control device 100 at the time of starting when the motorcycle 1 is braked off from the state where the brake is on and the accelerator is on will be described. FIG. 3 is a flowchart showing an example of the flow of the processing of the vehicle control device 100 according to the embodiment. In FIG. 3, a situation where the motorcycle 1 starts from a stopped state on a slope will be described as an example.

[0035] First, the acquisition unit 111 acquires the detection signal (acceleration data) of the acceleration sensor 30 and the detection signal (brake data) of the brake sensor 20 (step S101). Here, the acceleration data indicates the amount of acceleration operation by the occupant at that time, and the brake data indicates the off state in which the brake operation by the occupant is released.

[0036] Next, the torque setting unit 112 sets a target torque to be generated in the motor 5 based on the acquired acceleration data and torque reference information TD stored in the storage unit 120 in advance (step S103).

[0037] Next, the torque control unit 114 performs control to generate a torque corresponding to the set target torque in the motor 5 (step S105). FIG. 4 is a graph showing an example of the relationship between time and torque at the start of the motorcycle 1 according to the embodiment. In FIG. 4, the actual torque value is the torque generated in the motor 5 according to the control of the torque control unit 114. The command torque value is the torque corresponding to the amount of acceleration operation (command from the occupant) of the occupant. The time Tm_0 indicates the time (start time of starting) when the brake is turned off from the state where the brake is on and the accelerator is on. The time Tm_ta (time Tm_0 to starting time Tm_ta) indicates the starting time (for example, 100 ms). The torque Tq_ta indicates the target torque. As shown in FIG. 4, the torque control unit 114 controls to gradually increase the torque Tq from 0 during the starting time Tm_ta. During the starting time Tm_ta, the actual torque generated in the motor 5 according to the control of the torque control unit 114 is smaller than the command torque value. After the starting time Tm_ta has elapsed, the torque control unit 114 performs control so that the command torque value and the actual torque value match.

[0038] That is, when starting after the brake is turned off from the state where the brake is on and the accelerator is on, the torque control unit 114 gradually increases the torque generated in the motor 5, and at the time when a predetermined starting time (for example, 100 ms) has elapsed, the torque control of the motor 5 is performed so that the torque reaches the target torque. By performing such torque control, it is possible to suppress a sudden acceleration feeling at the start.

[0039] Next, the acquisition unit 111 acquires the detection signal (rotation speed data) of the rotation speed sensor 40 during the initial start time (step S107). Next, the time adjustment unit 113 adjusts the length of the initial start time according to the acquired rotation speed data (motor rotation speed) within the initial start time. The time adjustment unit 113 determines the positive or negative of the acquired motor rotation speed within the initial start time (determines whether the rotation speed < 0) (step S109).

[0040] When the time adjustment unit 113 determines that the acquired motor rotation speed is negative within the initial start time (step S109; YES), it shortens the length of the initial start time (step S111). FIG. 5 is a graph showing another example (rotation speed < 0) of the relationship between time and torque when the motorcycle 1 according to the embodiment starts. In the example shown in FIG. 5, at time Tm_1, the motor rotation speed is negative (rotation speed < 0), and it can be determined that the slippage of the motorcycle 1 has occurred. When the motor rotation speed thus becomes negative (rotation speed < 0), the time adjustment unit 113 shortens the length of the initial start time by changing the initial start time Tm_ta to an initial start time Tm_ta1 shorter than the initial start time Tm_ta. By performing such control (shortening) of the initial start time, when the torque is insufficient at the time of brake release, the torque can be increased promptly, so that, for example, it is possible to suppress the vehicle from slipping significantly on a slope.

[0041] When the time adjustment unit 113 determines that the acquired motor rotation speed is not negative within the initial start time (step S109; NO), it determines whether the increase rate per unit time of the motor rotation speed is equal to or greater than a threshold value (step S115). When the time adjustment unit 113 determines that the acquired motor rotation speed is equal to or greater than the threshold value within the initial start time (step S115; YES), it extends the length of the initial start time (step S117). On the other hand, when the time adjustment unit 113 determines that the acquired motor rotation speed is not equal to or greater than the threshold value within the initial start time (step S115; NO), it does not change the length of the initial start time.

[0042] FIG. 6 is a graph showing another example (rotation speed ≥ threshold value) of the relationship between time and torque when the motorcycle 1 according to the embodiment starts. In the example shown in FIG. 6, at time Tm_2, the increase rate of the motor rotation speed is equal to or greater than the threshold value (rotation speed ≥ threshold value). When the increase rate of the motor rotation speed becomes equal to or greater than the threshold value in this way, the time adjustment unit 113 changes the initial movement time Tm_ta to an initial movement time Tm_ta2 that is longer than the initial movement time Tm_ta, thereby extending or shortening the length of the initial movement time. By performing such control (extension) of the initial movement time, when torque more than necessary is output at the time of brake release, the torque can be gradually increased up to the target torque, so that a sudden acceleration feeling can be suppressed.

[0043] Next, the torque control unit 114 determines whether or not the torque of the motor 5 has reached the target torque (step S113). When the torque control unit 114 determines that the torque of the motor 5 has not reached the target torque (step S113; NO), it returns to step S109 and repeats the subsequent processing. On the other hand, when the torque control unit 114 determines that the torque of the motor 5 has reached the target torque (step S113; YES), it ends the processing of this flowchart.

[0044] As described above, the vehicle control device 100 according to the present embodiment includes a torque setting unit 112 that sets a target torque of the motor 5 according to the operation amount of the accelerator 2 when the saddle-riding type vehicle 1 is stopped and the brake 3 and the accelerator 2 are operated simultaneously, and when a predetermined initial movement time has elapsed after the saddle-riding type vehicle 1 starts, a torque control unit 114 that gradually increases the torque of the motor 5 so as to reach the set target torque, and a time adjustment unit 113 that changes the length of the initial movement time according to the rotation speed of the motor 5 during the initial movement time. By including these components, the operability when the saddle-riding type vehicle 1 starts can be improved.

[0045] As described above, an embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0046] 1 Motorcycle (straddle-type vehicle) 2 Grip part (accelerator) 3 Brake 4 Battery 5 Motor 6 Reduction mechanism 7 Swing arm 20 Brake sensor 30 Accelerator sensor 40 Rotation speed sensor 50 Gradient sensor 60 Weight sensor 100 Vehicle control device 110 Control unit 111 Acquisition unit 112 Torque setting unit 113 Time adjustment unit 114 Torque control unit 115 Power supply control unit 116 Notification unit 120 Storage unit

Claims

1. When the straddle-type vehicle (1) is stopped and the brake (3) and the accelerator (2) are operated simultaneously, and when the operation of the brake (3) is released and the straddle-type vehicle (1) starts moving, a torque setting unit (112) that sets a target torque of a motor (5) according to the operation amount of the accelerator (2); A torque control unit (114) that gradually increases the torque of the motor (5) so as to reach the set target torque when a predetermined initial movement time has elapsed after the straddle-type vehicle (1) starts moving; A time adjustment unit (113) that changes the length of the initial movement time according to the rotational speed of the motor (5) during the initial movement time; A vehicle control device comprising the above.

2. The time adjustment unit (113) shortens the initial movement time when the rotational speed of the motor (5) during the initial movement time is negative, assuming that the rotational speed of the motor (5) when the straddle-type vehicle (1) moves forward is positive. The vehicle control device according to Claim 1.

3. The time adjustment unit (113) extends the initial movement time when the increase rate of the rotational speed of the motor (5) during the initial movement time is equal to or greater than a predetermined threshold value. The vehicle control device according to Claim 1 or 2.

4. Further comprising a notification unit (116) that notifies the operation amount of the accelerator (2) according to at least one of the gradient of the straddle-type vehicle (1) and the weight of the occupant of the straddle-type vehicle (1). The vehicle control device according to Claim 1.

5. A computer, When the straddle-type vehicle (1) is stopped and the brake (3) and the accelerator (2) are operated simultaneously, and when the operation of the brake (3) is released and the straddle-type vehicle (1) starts moving, sets a target torque of the motor (5) according to the operation amount of the accelerator (2), Gradually increases the torque of the motor (5) so as to reach the set target torque when a predetermined initial movement time has elapsed after the straddle-type vehicle (1) starts moving, Changes the length of the initial movement time according to the rotational speed of the motor (5) during the initial movement time. A vehicle control method.

6. In a computer, When the straddle-type vehicle (1) is stopped and the brake (3) and the accelerator (2) are simultaneously operated, and when the operation of the brake (3) is released and the straddle-type vehicle (1) starts moving, a target torque of the motor (5) corresponding to the operation amount of the accelerator (2) is set. After a predetermined starting time has elapsed after the straddle-type vehicle (1) has started moving, the torque of the motor (5) is gradually increased so as to reach the set target torque. The length of the starting time is changed according to the rotational speed of the motor (5) during the starting time. Program.

Images