Control device of vehicle

Abstract

To provide a control device of a vehicle which performs brake control to have vehicle behavior a driver intends.SOLUTION: An electronic control device 70 comprises: an abnormality diagnosis part 74 which detects failure of a vehicle 10; and a brake control part 76 which performs, when a shift position POSsh is a neutral position (N position), an abnormality diagnosis part 74 detects no failure of the vehicle 10 not to be capable of traveling, and the vehicle does not travel, brake control to stop the vehicle 10, and does not perform, when the abnormality diagnosis part 74 detects failure of the vehicle 10 not to be capable of traveling, the brake control to stop the vehicle 10. Thereby, when the failure of the vehicle 10 not to be capable of traveling occurs, the brake control to stop the vehicle 10 is not performed so that vehicle movement can be performed with the N position in a case of the failure not to be capable of traveling. The control device of the vehicle is given to perform brake control to have vehicle behavior a driver intends.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle control device for suppressing vehicle behavior.

Background Art

[0002] There is disclosed a technique related to vehicle control for suppressing unintended movement of a vehicle even when a driver does not step on a brake pedal during parking on a slope or the like. For example, a vehicle control device described in Patent Document 1 is such a device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, parking without brake operation or brake setting of a vehicle is a state in which it is difficult to suppress unintended behavior of the vehicle, such as vehicle movement due to external force, misoperation, or malfunction, not limited to a slope. In particular, when the shift position of the vehicle is set to the neutral position where power transmission to the wheels is not performed, it becomes even more difficult to suppress the above behavior. As a countermeasure, it is conceivable to perform braking control to automatically apply a brake or the like on the vehicle side during parking in the neutral position. However, in the above braking control, there is a problem that, for example, when the vehicle becomes inoperable due to a failure and is set to the neutral position to move the vehicle, braking is performed and the vehicle behavior intended by the driver cannot be achieved.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle control device that performs braking control to achieve the vehicle behavior intended by the driver in the neutral position.

Means for Solving the Problems

[0006] The gist of the present invention is a control device for a vehicle having a neutral position where power transmission does not occur between a power source and wheels, the control device comprising: (b) an abnormality diagnosis unit that detects a failure of the vehicle; and (c) a braking control unit that, when the vehicle is in the neutral position and the abnormality diagnosis unit has not detected a failure of the vehicle that would render it inoperable and the vehicle is not in motion, performs braking control to stop the vehicle, but does not perform the braking control to stop the vehicle when the abnormality diagnosis unit has detected a failure of the vehicle that would render it inoperable.

Effect of the Invention

[0007] According to the present invention, the control device includes an abnormality diagnosis unit that detects a failure of the vehicle, and a braking control unit that, when the vehicle is in the neutral position and the abnormality diagnosis unit has not detected a failure of the vehicle that would render it inoperable and the vehicle is not in motion, performs braking control to stop the vehicle, but does not perform the braking control to stop the vehicle when the abnormality diagnosis unit has detected a failure of the vehicle that would render it inoperable. Thus, when a failure occurs that would render the vehicle inoperable, braking to stop the vehicle is not performed, so that the vehicle can move in the neutral position when such a failure occurs, and a control device for a vehicle that performs braking control resulting in the vehicle behavior intended by the driver can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

Embodiment

[0010] In FIG. 1, a vehicle 10 is a hybrid vehicle including a hybrid power source 50 and wheels 14.

[0011] The hybrid power source 50 includes an engine 12 and a trunk axle 52 incorporating an electric motor MG1 and an electric motor MG2, and power is transmitted from the hybrid power source 50 to the wheels 14 via a drive shaft 22.

[0012] The engine 12 is controlled by an engine control device 40 including a throttle actuator, a fuel injection device, an ignition device, etc. provided in the vehicle 10 by an electronic control device 70 described later, and the output torque of the engine 12 is controlled.

[0013] The trunk axle 52 includes a power split mechanism 54, an electric motor MG1, an electric motor MG2, an inverter 56, an inverter 58, a differential 20, a connecting gear group, etc., and is a unit constituting a known hybrid vehicle.

[0014] The vehicle 10 also includes a battery 60 as a power source for operating the electric motor MG1 and the electric motor MG2, and is connected to the inverter 56 and the inverter 58.

[0015] The electric motor MG1 is a so-called motor generator. The inverter 56 converts DC power from the battery 60 into AC power and supplies it to the electric motor MG1, or converts AC power generated by the electric motor MG1 into DC power and supplies it to the battery 60, and performs controls such as these. The electric motor MG2 and the inverter 58 each have the same functions as the electric motor MG1 and the inverter 56, and their descriptions are omitted.

[0016] In vehicle 10, the shift position POSsh, which is the driving position of vehicle 10, is switched. The shift position POSsh is, for example, the P, R, N, or D position. The P position indicates the parking position, the R position indicates the reverse driving position, the N position indicates the neutral position, and the D position indicates the forward driving position.

[0017] In the case of the D position (forward driving), the power (driving torque) output from the engine 12, the motor MG1, and the motor MG2 is transmitted to the wheels 14, respectively. In the case of the R position (reverse driving), the motor MG2 generates power (driving torque) in the rotational direction opposite to forward driving, and the power (driving torque) is transmitted to the wheels 14. In the P position and the N position, no power transmission occurs between any of the engine 12, the motor MG1, the motor MG2, and the wheels 14.

[0018] Vehicle 10 further includes a brake control device 42, a parking brake control device 46, an abnormality notification device 94, and the like.

[0019] The brake control device 42 controls the braking force of the wheel brakes 44 provided on the wheels 14, respectively.

[0020] The parking brake control device 46 is a device that operates the parking brake 48 provided on the wheels 14 to stop the wheels 14 from rotating, and is controlled by an electronic control device 70 described later when the shift position POSsh is selected to be the P position.

[0021] The abnormality notification device 94 is a device that notifies the driver that a vehicle failure has occurred in vehicle 10, for example, a vehicle failure that leads to inoperability, and is arranged, for example, on the console of the driver's seat.

[0022] Vehicle 10 includes an electronic control unit 70 as a controller of the vehicle 10, and is configured to include a so-called microcomputer. Various sensors and the like provided in the vehicle 10 (for example, wheel speed sensor 80, accelerator opening sensor 82, brake operation amount sensor 84, MG1 rotation speed sensor 86, MG2 rotation speed sensor 88, shift selection device 90, obstacle detection sensor 92, etc.) supply various signals based on the detected values (for example, signals such as wheel speed Nw which is the rotation speed of wheel 14, accelerator opening θa which is the accelerator operation amount representing the magnitude of the driver's acceleration operation, brake operation amount θb which is the magnitude of the driver's brake operation, MG1 rotation speed Nm1, MG2 rotation speed Nm2, shift selection signal Psp, various information Adr of obstacle detection, etc.). Also, the vehicle speed V is obtained from the wheel speed Nw of the wheel 14.

[0023] The shift selection device 90 is an operating device for selecting the shift position POSsh of the vehicle 10, and P, R, N, D, M selection signals Psp corresponding one-to-one to the P, R, N, D positions of the shift position POSsh selected by the operation are supplied to the electronic control unit 70.

[0024] The obstacle detection sensor 92 is a sensor used for detecting obstacles around the vehicle 10, and various information Adr of obstacle detection is supplied from, for example, a camera, millimeter wave radar, laser radar, etc.

[0025] From the electronic control unit 70, various command signals (for example, engine control command signal Se, MG1 control command signal Sm1 for controlling the torque of the electric motor MG1, MG2 control command signal Sm2 for controlling the torque of the electric motor MG2, brake control command signal Sb, parking brake operation command signal Sp, vehicle failure information Eif, etc.) are output to each device provided in the vehicle 10 (for example, engine control unit 40, inverter 56, inverter 58, brake control unit 42, parking brake control unit 46, abnormality notification device 94, etc.).

[0026] The electronic control unit 70 functionally includes a drive control unit 72, an abnormality diagnosis unit 74, and a brake control unit 76.

[0027] The drive control unit 72 performs control related to the running of the vehicle 10. For example, the drive control unit 72 calculates a required drive torque Tr for the vehicle 10 by the driver by applying the accelerator opening θa and the vehicle speed V to a predetermined drive demand amount map. The drive control unit 72 outputs an engine control command signal Se to the engine control device 40, an MG1 control command signal Sm1 to the inverter 56, and an MG2 control command signal Sm2 to the inverter 56 so that the drive torques respectively output from the engine 12, the electric motor MG1, and the electric motor MG2 achieve the required drive torque Tr.

[0028] The drive control unit 72 outputs a brake control command signal Sb to the brake control device 42 so as to obtain a braking force corresponding to the brake operation amount θb. Further, when the shift position POSsh is selected to the P position, the drive control unit 72 outputs a parking brake operation command signal Sp to the parking brake control device 46 so as to operate the parking brake 48.

[0029] The abnormality diagnosis unit 74 detects the occurrence of a vehicle failure in the vehicle 10. For example, when detecting the occurrence of a vehicle failure that leads to inability to run, the abnormality diagnosis unit 74 outputs vehicle failure information Eif to the brake control unit 76 and the abnormality notification device 94.

[0030] When the shift position POSsh is in the N position, the brake control unit 76 performs brake control to stop the vehicle 10 by a control operation described in the flowchart of FIG. 2 described later.

[0031] FIG. 2 is a flowchart for explaining the main part of the control operation of the electronic control unit 70 including the brake control unit 76, and is repeatedly executed, for example.

[0032] First, in step S10 corresponding to the braking control unit 76 (hereinafter, steps are omitted), it is determined whether the shift position POSsh is selected to the N position by the shift selection device 90. If the determination in S10 is negative, this routine is terminated.

[0033] If the determination in S10 is positive, in S20 corresponding to the abnormality diagnosis unit 74, it is determined whether a failure that causes the vehicle 10 to become inoperable has occurred, that is, whether vehicle failure information Eif is output from the abnormality diagnosis unit 74. If the determination in S20 is positive, the process proceeds to S50.

[0034] If the determination in S20 is negative, in S30 corresponding to the braking control unit 76, it is determined whether the vehicle 10 is in motion. If the determination in S30 is positive, this routine is terminated. The determination of whether the vehicle 10 is in motion is preferably performed based on whether any one or more of the following three determinations are satisfied. The first is whether the wheel speed Nw of the wheel 14 exceeds a predetermined determination threshold value for determining that the vehicle is in motion, for example. The second is whether the MG2 rotational speed Nm2 of the electric motor MG2 connected via the connection gear group to the wheel 14 exceeds a predetermined determination threshold value for determining that the vehicle is in motion, for example. The third is whether all the detected surrounding obstacles are moving at a speed exceeding a predetermined determination threshold value based on various information Adr from the obstacle detection sensor 92.

[0035] When the determination in S30 is affirmative, S50 described later is executed. When the determination is negative, in S40 corresponding to the braking control unit 76, a braking control command signal St for braking the vehicle 10 is output from the braking control unit 76 to the drive control unit 72, and braking control for stopping the vehicle 10 is performed by the drive control unit 72, and this routine is terminated. The braking control for stopping the vehicle 10 is preferably performed by the drive control unit 72, for example, in the following three ways. First, a parking brake operation command signal Sp is output to the parking brake control device 46 so as to operate the parking brake 48. Second, when a brake operation amount θb by the driver is recognized, a brake control command signal Sb is output to the brake control device 42 so as to maintain the braking force of the wheel brake 44 according to the brake operation amount θb. Third, an MG2 control command signal Sm2 is output to the inverter 58 so that the electric motor MG2 connected via the connecting gear group to the wheel 14 generates torque in the direction opposite to the behavior direction of the vehicle 10.

[0036] In S50 corresponding to the braking control unit 76 where the determination in S20 is affirmative, a braking control command signal St for releasing the braking of the vehicle 10 is output from the braking control unit 76 to the drive control unit 72. By the drive control unit 72, with a signal output opposite to the braking control in S40 described above, control for releasing the braking of the vehicle 10 is performed in the N range, and this routine is terminated.

[0037] As described above, according to this embodiment, the electronic control device 70 includes an abnormality diagnosis unit 74 that detects a failure of the vehicle 10, and when the shift position POSsh is in the N position, the abnormality diagnosis unit 74 has not detected a failure of the vehicle 10 that leads to inoperability, and when the vehicle is not in motion, braking control for stopping the vehicle 10 is performed. However, when the abnormality diagnosis unit 74 has detected a failure of the vehicle 10 that leads to inoperability, it includes a braking control unit 76 that does not perform braking control for stopping the vehicle 10. Thereby, when a failure occurs that leads to inoperability of the vehicle 10, braking for stopping the vehicle 10 is not performed, so that the vehicle can move in the N position when a failure occurs that leads to inoperability, and a control device for a vehicle that performs braking control resulting in the vehicle behavior intended by the driver can be provided.

[0038] As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is also applicable to other aspects.

[0039] For example, the vehicle in the above-described embodiment is a hybrid vehicle including the engine 12, the motor MG1, and the motor MG2. However, the present invention can also be applied to a vehicle having only the engine 12 as a power source or an electric vehicle having only a motor as a power source.

[0040] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, these are merely one embodiment, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

Description of Reference Numerals

[0041] 10: Vehicle 12: Engine 14: Wheel 70: Electronic control unit (control unit) 74: Abnormality diagnosis unit 76: Brake control unit MG1: Motor MG2: Motor POSsh: Shift position Eif: Vehicle failure information

Claims

[Claim 1] A control device for a vehicle having a neutral position in which no power is transmitted between a power source and a wheel, an abnormality diagnosis unit that detects a malfunction of the vehicle; a braking control unit that, in the neutral position, performs braking control to stop the vehicle when the abnormality diagnosis unit has not detected a malfunction of the vehicle that would cause the vehicle to be unable to run and the vehicle is not running, but does not perform the braking control to stop the vehicle when the abnormality diagnosis unit has detected a malfunction of the vehicle that would cause the vehicle to be unable to run.

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