vehicle

Abstract

To prevent unintentional braking force from being applied on a vehicle by erroneous operation.SOLUTION: A vehicle, which can switch between a first mode in which first regenerative braking force is applied and a second mode in which second regenerative braking force different from the first regenerative braking force is applied, includes a mode selection device which outputs a mode selection signal indicating a mode selected by driver operation is either the first mode or the second mode, and a control device which controls the regenerative braking force on the basis of the mode selected by inputting the mode selection signal. The control device controls the regenerative braking force on the basis of the first mode until a predetermined time passes after the mode selection signal is switched when the mode selection signal indicating the first mode is switched to the mode selection signal indicating the second mode, and controls the regenerative braking force on the basis of the second mode when cancel operation is carried before the predetermined time passes after the mode selection signal is switched.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to vehicles such as electric vehicles. In this specification, the term "electric vehicle" broadly refers to a vehicle in which one or more wheels are driven by a motor, and includes, for example, a rechargeable vehicle that is charged by an external power source, a hybrid vehicle that also has an engine, and the like. [Background technology]

[0002] There are known vehicles that are capable of switching the regenerative braking force applied to the vehicle in a coasting state caused by an accelerator release operation according to a driver's selection, and one example of such vehicles is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 189904 Summary of the Invention [Problem to be solved by the invention]

[0004] If an unintended mode is selected due to an erroneous operation by the driver, a braking force unintended by the driver will be applied to the vehicle. A technology is required to prevent an unintended braking force from being applied to the vehicle due to an erroneous operation. [Means for solving the problem]

[0005] The vehicle disclosed in this specification is a vehicle that can be switched between a first mode in which a first regenerative braking force is applied and a second mode in which a second regenerative braking force different from the first regenerative braking force is applied. The magnitude relationship between the first regenerative braking force and the second regenerative braking force is not particularly limited. The vehicle can include a mode selection device that outputs a mode selection signal indicating whether the mode selected by the driver's operation is the first mode or the second mode, and a control device that inputs the mode selection signal and controls the regenerative braking force based on the selected mode. When the mode selection signal indicating the first mode is switched to the mode selection signal indicating the second mode, the control device controls the regenerative braking force based on the first mode until a certain time has elapsed since the mode selection signal was switched, and controls the regenerative braking force based on the second mode when a cancel operation has not been performed until the certain time has elapsed since the mode selection signal was switched.

[0006] In the vehicle, when switching from the first mode to the second mode, a period is provided for accepting a cancel operation by the driver. Therefore, if the driver who notices an erroneous operation executes a cancel operation within this period, the switching from the first mode to the second mode is stopped and the first mode intended by the driver is maintained. In this way, it is possible to prevent a braking force unintended by the driver from being applied to the vehicle due to an erroneous operation by the driver. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram of a drive system of an electric vehicle according to an embodiment of the present invention. [Diagram 2] 3 is a flowchart of control performed by a control device for an electric vehicle according to the present embodiment. [Diagram 3] FIG. 4 is a diagram showing mode transition between a normal regeneration mode and a strong regeneration mode of the electric vehicle of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An electric vehicle 2 according to an embodiment will be described with reference to the drawings. FIG. 1 is a block diagram of a drive system of the electric vehicle 2. The electric vehicle 2 runs using a driving force generated by a motor 10. The electric vehicle 2 has a battery 14 that supplies power to the motor 10, an inverter 12 that is connected between the motor 10 and the battery 14 and converts the power between direct current and alternating current, and a control device 16 that controls devices such as the inverter 12. The electric vehicle 2 further has a drive shaft 6 and a differential gear 8. The drive shaft 6 and the differential gear 8 are configured to transmit driving force from the motor 10 to a pair of front wheels 4, which are drive wheels.

[0009] The motor 10 is configured as a three-phase AC rotating electric machine with a rotor in which a permanent magnet is embedded. The DC power supply from the battery 14 is boosted by a converter (not shown), and then converted to three-phase AC by an inverter 12 and supplied to the motor 10, causing the rotor of the motor 10 to rotate and generate driving force. The driving force generated by the motor 10 is input to the drive shaft 6 via a differential gear 8 and transmitted to the pair of front wheels 4. This causes the electric vehicle 2 to run.

[0010] The motor 10 can also function as a generator. The motor 10 generates regenerative power by reverse driving and applies regenerative braking force to the wheels. The regenerative power, which is AC, is converted to DC by the inverter 12. The regenerative power converted to DC is supplied to a converter (not shown), where it is stepped down and supplied to the battery 14. In this way, the electric vehicle 2 can charge the battery 14 using the regenerative power.

[0011] The electric vehicle 2 further includes an accelerator pedal 22, a brake pedal 24, a selection device 32, and an alarm device .

[0012] The selection device 32 is a device that outputs a mode selection signal S10 indicating a mode selected by a driver's operation. Here, the electric vehicle 2 is a vehicle that can be switched between a normal regeneration mode in which a first regenerative braking force is applied and a strong regenerative mode in which a second regenerative braking force is applied. The regenerative braking force applied to the vehicle in the strong regenerative mode is greater than the regenerative braking force applied to the vehicle in the normal regenerative mode. For example, in a coasting state due to an accelerator release operation, the regenerative braking force applied to the vehicle in the strong regenerative mode is greater than the regenerative braking force applied to the vehicle in the normal regenerative mode. The first regenerative braking force in the normal regenerative mode may be adjusted according to an accelerator operation. The second regenerative braking force in the strong regenerative mode may also be adjusted according to an accelerator operation. The normal regenerative mode is, for example, a mode called "B range". The strong regenerative mode is a mode in which acceleration and deceleration can be controlled only by the accelerator pedal 22 without using the brake pedal 24, and is, for example, a mode called "one pedal mode". Although only two modes are illustrated in this example, the selection device 32 may be capable of selecting three or more modes by the driver's operation.

[0013] The mode selection signal S10 output by the selection device 32 is input to the control device 16. Based on the mode selection signal S10, the control device 16 determines whether the selected mode is a normal regeneration mode or a strong regeneration mode. The control device 16 controls the inverter 12 based on the selected mode and adjusts the regenerative braking force according to the accelerator operation. The control device 16 further notifies the driver of the selected mode via the notification device 34. The notification device 34 is not particularly limited, and may be, for example, a display unit (e.g., a light turned on) provided on the instrument panel.

[0014] FIG. 2 is a flowchart showing a procedure of a process executed by the control device 16 when the strong regeneration mode is further selected after the normal regeneration mode is selected by the driver's operation.

[0015] First, in step S1, when the driver selects the normal regeneration mode via the selection device 32, the selection device 32 outputs a mode selection signal S10 indicating the normal regeneration mode.

[0016] In step S2, the control device 16 transitions to the normal regeneration mode based on the mode selection signal S10. As a result, the control device 16 controls the inverter 12 based on the normal regeneration mode and adjusts the regenerative braking force according to the accelerator operation. In addition, the control device 16 uses the notification device 34 to notify the driver that the selected mode is the normal regeneration mode.

[0017] In step S3, when the driver selects the strong regeneration mode via the selection device 32, the selection device 32 outputs a mode selection signal S10 indicating the strong regeneration mode.

[0018] In step S4, the control device 16 transitions to the transition mode when the mode selection signal S10 indicating the normal regeneration mode is switched to the mode selection signal S10 indicating the strong regeneration mode. The transition mode is a mode in which the mode before the transition, i.e., the normal regeneration mode, is maintained for a certain period of time. The certain period of time during which the transition mode continues after the mode selection signal S10 is switched is appropriately set, for example, between 1 millisecond and 5000 milliseconds. The lower limit value is a sufficient time for the driver to recognize that the vehicle is about to transition to a mode and to perform a cancellation operation. The upper limit value is a time that does not cause the driver to mistakenly believe that there is a malfunction or an operation failure due to the actual change in braking force being too slow. In addition, the control device 16 uses the notification device 34 to notify the driver that the selected mode is the strong regeneration mode.

[0019] In step S5, the control device 16 determines whether or not the driver performs a cancel operation during the transition mode period. The cancel operation in this example is an operation in which the driver reselects the normal regeneration mode via the selection device 32. If the driver performs a cancel operation, the process proceeds to step S6, where the control device 16 transitions to the strong regeneration mode. If the driver performs a cancel operation, the process proceeds to step S7, where the control device 16 transitions to the normal regeneration mode. Furthermore, if a cancel operation is performed, the control device 16 uses the notification device 34 to notify the driver that the selected mode is the normal regeneration mode.

[0020] For example, when the driver is driving in the normal regeneration mode, the strong regeneration mode may be selected due to an erroneous operation of the selection device 32. In this case, a strong braking force unintended by the driver is applied to the vehicle. As described above, in the electric vehicle 2, when switching from the normal regeneration mode to the strong regeneration mode, the control device 16 transitions to the transition mode, providing a period for accepting a cancel operation by the driver. Therefore, if the driver who notices the erroneous operation executes a cancel operation during this period, the switching from the normal regeneration mode to the strong regeneration mode is stopped, and the normal regeneration mode is maintained. In this way, it is possible to avoid a braking force unintended by the driver being applied to the vehicle due to an erroneous operation by the driver.

[0021] In the above description, an example of transition to the transition mode when transitioning from the normal regeneration mode to the strong regeneration mode has been described. Similarly, transition to the transition mode may occur when transitioning from the strong regeneration mode to the normal regeneration mode. As shown in FIG. 3, the electric vehicle 2 may be configured to transition to the transition mode when transitioning in either direction between the normal regeneration mode and the strong regeneration mode. In this example, when transitioning in either direction between the normal regeneration mode and the strong regeneration mode, application of a braking force unintended by the driver due to an erroneous operation by the driver is avoided.

[0022] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0023] 2: Electric vehicles 4: Front wheel 6: Drive shaft 8: Differential gear 10: Motor 12: Inverter 14: Battery 16: Control device 22: Accelerator pedal 24: Brake pedal 32: Selection device 34: Notification device

Claims

[Claim 1] A vehicle that can be switched between a first mode in which a first regenerative braking force is applied and a second mode in which a second regenerative braking force different from the first regenerative braking force is applied, a mode selection device that outputs a mode selection signal indicating whether a mode selected by a driver's operation is the first mode or the second mode; a control device that receives the mode selection signal and controls a regenerative braking force based on the selected mode, The control device, when the mode selection signal is switched from the first mode to the second mode, controls the regenerative braking force based on the first mode until a certain time has elapsed since the mode selection signal was switched, and controls the regenerative braking force based on the second mode when a cancellation operation is not performed until the certain time has elapsed since the mode selection signal was switched.

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