JP2022152515A - Vehicle control device - Google Patents

Abstract

To provide a vehicle control device capable of safely maintaining a parked state even when a brake sensor is abnormal.SOLUTION: A vehicle control device includes: a shift selection part 18 capable of selecting at least a parking range; a brake sensor 22 for detecting the depression state of a brake pedal; a vehicle speed sensor 23 for detecting a vehicle speed; and a control unit 40 for permitting shifting to the parking range when the brake sensor 22 detects the state in which the brake pedal is depressed and a vehicle is determined to be in a stopped state based on the vehicle speed. When an abnormality related to the brake sensor 22 is detected, the control unit 40 permits shifting to the parking range if the vehicle is determined to be in a stop state based on the vehicle speed and the stopped state continues for a predetermined period of time.SELECTED DRAWING: Figure 3

Description

The present invention relates to a control device for a vehicle, and more particularly to a control device for a vehicle that performs fail-safe control when an abnormality related to a brake sensor is detected.

There is a foot brake device that controls the braking force of a vehicle based on the driver's stepping operation of the brake pedal, and the stepping state of the brake pedal is detected by a brake sensor such as a brake fluid pressure sensor and a stroke sensor. There have been proposed methods for detecting an abnormality in a brake sensor that detects the depressed state of the brake pedal (Patent Documents 1 and 2).

JP 2006-240617 A JP 2018-103848 A

Now, the brake sensor not only detects the original state of depression of the brake pedal, but also the detection result of the brake sensor is used for various purposes. For example, it is also used as a selection condition for a shift range in which a shift stage is set by a driver operating a shift lever or the like.

A plurality of shift ranges are provided, and for example, a parking range (P range), a reverse range (R range), a neutral range (N range), and a driving range (D range) are set. Of these, it is desirable that the switching from the driving range, the reverse range, and the neutral range to the parking range be performed while the vehicle is surely stopped. Therefore, when it is detected that the vehicle is stopped based on the information from the vehicle speed sensor and that the brake pedal is depressed based on the information from the brake sensor, the driving range is changed to the parking range. is allowed to switch to

However, if an abnormality related to the brake sensor occurs, such as when the signal from the brake sensor is interrupted, it will not be detected that the brake pedal is depressed, so the system will shift from the driving range, reverse range, and neutral range to the parking range. switching is not permitted. In such a case, it is conceivable to operate the parking brake in the driving range or neutral range to maintain the stopped state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to provide a vehicle control device that can safely maintain a parked state even when there is an abnormality related to the brake sensor of the vehicle. for the purpose.

The present invention has been made to solve at least part of the above problems, and can be implemented as the following aspects or application examples.

A control device for a vehicle according to this application example includes a shift range selection unit capable of selecting at least a parking range and other shift ranges, a brake state detection unit that detects a depression state of a brake pedal, and a vehicle speed detection unit that detects a vehicle speed. When the state in which the brake pedal is depressed is detected by the detection unit and the brake state detection unit, and the vehicle is determined to be in a stopped state from the vehicle speed detected by the vehicle speed detection unit, the other shift is performed. a control unit for permitting shift switching from the range to the parking range, wherein the control unit, when detecting an abnormality related to the brake state detection unit, adjusts the vehicle speed from the vehicle speed detected by the vehicle speed detection unit. is determined to be in a stopped state and the stopped state continues for a predetermined time, the shift switching from the other shift range to the parking range is permitted.

If an abnormality related to the brake state detection unit (for example, brake fluid pressure sensor or stroke sensor) occurs, conventional control cannot switch from other ranges (driving range, reverse range, or neutral range) to parking range. , the driver will operate the parking brake or the like in the shift range such as the driving range to maintain the parking state. On the other hand, in the present invention having the above configuration, when an abnormality is detected in the brake state detection section, the control section determines whether or not the vehicle is surely stopped for a predetermined time or longer based on the vehicle speed, and the vehicle is stopped. Fail-safe control is performed to permit switching to the parking range when it is determined to be in this state.

Therefore, when the brake state detector is normal, switching to the parking range can be permitted quickly based on the depression of the brake. Even when the brake state detection unit is abnormal, if it can be confirmed from the vehicle speed that the vehicle is surely stopped, switching to the parking range is permitted, so that the vehicle is stopped. It is possible to prevent a state in which switching to the parking range cannot be performed even though the vehicle is in the parking range. This also solves the problem that the power generator cannot be shut down when, for example, the condition for shutting down the power generator of the vehicle includes being in the parking range.

As a result, even when there is an abnormality related to the brake sensor of the vehicle (sensor abnormality, sensor signal abnormality), the parking state can be safely maintained.

1 is a schematic configuration diagram of a vehicle to which a vehicle control device according to an embodiment of the invention is applied; FIG. FIG. 4 is a schematic top view of an example of a shift selector; 1 is a block diagram of a control system of a vehicle control device according to an embodiment of the present invention; FIG. 4 is a flow chart showing a fail-safe control routine executed by the vehicle control device according to the embodiment of the present invention;

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing main parts of a driving system of a vehicle 10 to which a vehicle control device 1 according to an embodiment of the invention is applied. The vehicle 10 runs when the power generation unit 11 generates driving force, and the driving force is transmitted to the left and right drive wheels 14 via the power transmission unit 12 and the drive shaft 13 . The power generation section 11 of the present embodiment is an engine (internal combustion engine), and the output shaft (not shown) of the power generation section 11 is connected to the input shaft (not shown) of the automatic transmission 15 in the power transmission section 12 to provide an automatic transmission. An output shaft 16 of the transmission 15 is connected to the drive shaft 13 via a differential mechanism 17 . The vehicle 10 may be an electric vehicle in which the power generating section 11 is a driving motor, or may be a hybrid vehicle having an engine and a driving motor as the power generating section. Further, the automatic transmission 15 in the power transmission section 12 may be a reduction gear in the case of an electric vehicle in which the power generation section 11 is a driving motor.

The vehicle 10 includes a shift selection section (shift range selection section) 18 such as a shift lever near the driver's seat. FIG. 2 is a schematic top view showing the shift selector 18 of this embodiment. The shift selection unit 18 is a device including a shift lever and a switch that can be operated by the driver to select a shift range, mainly for instructing a shift change. The shift positions that can be selected by the shift selection unit 18 include a neutral range (N) in which the gear of the automatic transmission 15 is neutral, a driving range (D) selected when traveling forward, a reverse range (R) selected when traveling backward, There is a parking range (P) (hereinafter referred to as P range) that is selected when parking. Further, although not shown in FIG. 2, other ranges such as a manual range (M) in which the gear stage can be manually shifted up or down can be provided.

Further, in this embodiment, selection of the P range is performed by depressing a push button type P range switch 25 having an operation lamp 24 as shown in FIG. In this embodiment, the push button type P range switch 25 is used, but it may be provided so that it can be operated by a shift lever in the same manner as other ranges.

The automatic transmission 15 shifts the power generated by the power generator 11 in accordance with the vehicle speed and transmits the power to the drive wheels 14 . The automatic transmission 15 is a so-called automatic transmission, and is controlled to automatically select a predetermined gear stage based on control information from a control section 40, which will be described later. For example, when the drive range (hereinafter referred to as D range) is selected as the shift range by the shift selection unit 18 , the driving force of the power generation unit 11 is transmitted to the left and right drive wheels 14 . On the other hand, when the shift selection unit 18 selects the neutral range (hereinafter referred to as N range), transmission of driving force from the power generation unit 11 to the left and right drive wheels 14 is cut off.

Vehicle 10 further includes a parking lock 19 on the output side of output shaft 16 of automatic transmission 15 . The parking lock 19 is for restraining the output shaft 16 of the automatic transmission 15 and maintaining the parked state of the vehicle 10 when the shift range is the P range. Specifically, a lock lever with a pawl meshes with a fixed gear provided on the output shaft 16 of the automatic transmission 15 of the vehicle 10 to restrain the rotation of the output shaft 16 . The parking lock 19 includes a parking lock electric actuator (not shown), and the operation of the parking lock electric actuator is controlled by a control unit 40, which will be described later, to drive a lock lever with a claw.

The vehicle 10 has an accelerator pedal 20a near the driver's seat. The accelerator pedal 20a is a pedal for giving an instruction to accelerate or decelerate the vehicle 10 according to the depression operation of the driver.

The vehicle 10 has an accelerator opening sensor 20 . The accelerator opening sensor 20 has a function of detecting the depressed state of the accelerator pedal 20 a and outputs the detected result to the control unit 40 .

The vehicle 10 has a brake pedal 22a near the driver's seat. The brake pedal 22a is a pedal for the driver to instruct braking. The vehicle 10 decelerates or stops the vehicle 10 by applying a braking force to the drive wheels 14 and the like by an actuator (not shown) that operates according to the operation of the brake pedal 22a.

The vehicle 10 includes a brake sensor 22 (brake state detector). The brake sensor 22 has a function of detecting the depressed state of the brake pedal 22a. Specifically, the brake sensor 22 detects the pressure Bp of the brake fluid corresponding to the force applied to the brake pedal 22a, and outputs it to the controller 40 as an analog voltage value.

The vehicle 10 includes a vehicle speed sensor (vehicle speed detection unit) 23 that detects a vehicle speed V of the vehicle 10 and outputs the detected vehicle speed V to the control unit 40 . As the vehicle speed sensor 23, a sensor that detects the rotation speed of the driving wheels 14 or driven wheels (not shown) or a sensor that detects the rotation speed of the crankshaft of the engine, which is the power generation unit 11, can be applied.

Each unit of the vehicle 10 configured in this way is connected to a control unit 40 mounted on the vehicle 10 . The control unit 40 is a control unit composed of an electronic arithmetic device, for example, a VCU (Vehicle Control Unit), and includes various components and various sensors of the vehicle control device 1 and CAN (Controller Area Network). Communication is possible via a communication network. In this embodiment, the control unit 40 mainly operates according to a predetermined program installed in advance, and has a function of detecting an abnormality related to the brake sensor 22 and controlling shift range switching. Note that the control unit 40 may be composed of a plurality of control units. For example, a unit that determines an abnormality related to the brake sensor 22 and a unit that controls switching of the shift range (so-called CLU: Change Lever Unit) are linked. to perform the following control.

FIG. 3 is a block diagram of the control system of the vehicle control device 1 according to one embodiment of the present invention. The configuration and functions of the vehicle control device 1 will be described below with reference to this figure.

The vehicle control device 1 includes an automatic transmission 15, a shift selector 18, a parking lock 19, an accelerator opening sensor 20, a brake sensor 22, a vehicle speed sensor 23, and a controller 40 communicably connected to them. Prepare. The control unit 40 includes a detection state determination unit 41 and a shift switching control unit 42 that are communicably connected to each other.

The parking lock 19 operates the parking lock electric actuator when the controller 40 permits switching to the P range. The parking lock 19 includes a parking lock operating switch, for example, a limit switch (not shown) that detects that the lock lever is engaged, and parking lock operating information indicating the operating state of the parking lock 19 or parking lock indicating the unlocked state. It has a function of generating release information and outputting it to the control unit 40 . Here, the operating state of the parking lock 19 means the state in which the lock lever is engaged with the fixed gear, and the released state means the state in which the lock lever is disengaged from the fixed gear.

The shift selection unit 18 has a function of generating request information for the selected shift range and outputting it to the control unit 40 . For example, when the P range is selected, the P range request information is output to the control unit 40, and when the D range is selected, the D range request information is output to the control unit 40.

Further, when the shift selection unit 18 acquires the P range determination information output from the control unit 40, the P range operation lamp 24 is lit. That is, immediately after the driver presses the P range switch 25 in the shift selection section 18 shown in FIG. After the operation is completed, the control unit 40 outputs the P range confirmation information to the shift selection unit 18, so that the operation lamp 24 is lit. In this embodiment, the shutdown (engine stop) of the power generation unit 11 of the vehicle 10 is performed not only when the shift selection unit 18 selects the P range, but also when the control unit 40 determines the P range. only possible.

The control unit 40 has a function of controlling input/output of information from the automatic transmission 15 , the shift selection unit 18 , the accelerator opening sensor 20 , the brake sensor 22 and the vehicle speed sensor 23 .

The detection state determination unit 41 acquires and monitors the pressure Bp detected by the brake sensor 22 as an analog voltage value, and determines whether the operation of the brake sensor 22 and the signal output from the sensor are normal or abnormal (brake sensor abnormality judgement). Specifically, when the analog voltage value of the pressure Bp is out of the set range (out of range), the output signal is interrupted due to disconnection of the harness, or the sensor is fixed, the detection state determination unit 41 detects the brake sensor. 22 is determined to be abnormal. If it is not determined to be abnormal, it is determined to be normal. The detection state determination unit 41 also determines whether or not the brake pedal 22a is depressed based on the pressure Bp (brake pedal depression determination).

When the shift switching control section 42 acquires the P range request information from the shift selecting section 18, it performs the following control. That is, when the detection state determination unit 41 determines that the operation of the brake sensor 22 is normal, the shift switching control unit 42 determines that the brake pedal 22a is depressed based on the pressure Bp detected by the brake sensor 22. When it is determined that the vehicle 10 is stopped based on the vehicle speed V detected by the vehicle speed sensor 23, the shift selector 18 performs control to permit switching from a shift range other than the P range to the P range. have

Further, when the detection state determination unit 41 detects an abnormality related to the brake sensor 22, the shift switching control unit 42 determines that the vehicle 10 is stopped based on the vehicle speed V detected by the vehicle speed sensor 23. In addition, when the stopped state continues for a predetermined time T or longer, the shift selector 18 has a function of permitting switching from a shift range other than the P range to the P range. Determination of the stopped state of the vehicle 10 by the vehicle speed sensor 23 is performed, for example, when the vehicle speed V detected by the vehicle speed sensor 23 is equal to or lower than a predetermined speed. This predetermined speed may be set differently depending on whether the brake sensor 22 is normal or abnormal. 22 is assumed to be 0.5 km/h. In this manner, the second predetermined speed V2 is preferably set to a vehicle speed lower than the first predetermined speed V1 in order to determine that the vehicle is surely stopped.

When the shift switching control unit 42 permits switching to the P range, the shift switching control unit 42 performs control to operate the parking lock 19 . Further, the shift switching control unit 42 acquires parking lock operation information indicating that the operation of the parking lock 19 has been completed, generates P range determination information indicating that switching to the P range has been completed, and shift selection. Output to unit 18 .

Further, the control unit 40 permits the shutdown of the power generation unit 11 when the P range determination information is generated by the shift switching control unit 42 . That is, after the vehicle 10 stops and the P range is determined, when the driver operates a switch (for example, an ignition switch) for stopping the power generation section 11 near the driver's seat, the control section 40 causes the power generation section 11 to be turned off. Shut down.

On the other hand, if the above condition is not satisfied, the shift switching control unit 42 performs control that does not permit (disallow) switching from a shift range other than the P range to the P range by the shift selection unit 18 . That is, the shift switching control unit 42 does not operate the parking lock 19, and the P range is not determined.

The control unit 40 of the vehicle control device 1 configured as described above operates based on the vehicle speed V even if an abnormality related to the brake sensor 22 occurs when the shift selection unit 18 selects the P range. When it is determined that the stopped state of the vehicle 10 has continued for a predetermined time T or longer, a fail-safe control is performed to permit the P range operation for activating the parking lock 19 .

FIG. 4 shows a flowchart showing a fail-safe control routine executed by the vehicle control device 1 according to one embodiment of the present invention, and the following description will be made along the same flowchart. The control routine starts when the P range is selected by the shift selector 18, that is, when the shift selector 18 generates the P range request information.

First, as step S1, the control unit 40 acquires the P range request information from the shift selection unit 18 in the shift switching control unit 42, and proceeds to step S2.

In subsequent step S2, the control unit 40 determines whether or not an abnormality related to the brake sensor 22 has occurred in the detection state determination unit 41 (brake sensor abnormality determination). If the determination result is true (Yes), that is, if there is an abnormality related to the brake sensor 22, the process proceeds to step S7. If the determination result is false (No), that is, if the brake sensor 22 is normal, the process proceeds to step S3.

In step S<b>3 , the shift switching control unit 42 of the control unit 40 determines whether the vehicle 10 is stopped based on the vehicle speed V acquired from the vehicle speed sensor 23 . Specifically, as the first stop state of the vehicle 10, it is determined whether or not the vehicle speed V is less than the first predetermined speed V1. The first predetermined speed V1 is set at, for example, 2.0 km per hour in this embodiment. If the determination result is true (Yes), the process proceeds to step S4.

As step S4, the control unit 40 determines whether or not the brake pedal 22a is depressed in the detection state determination unit 41 (brake pedal depression determination). Specifically, it is determined whether or not the pressure Bp acquired from the brake sensor 22 is greater than a predetermined pressure Bp1. The predetermined pressure Bp1 is set at 0.5 MPa, for example. If the determination result is true (Yes), the process proceeds to step S5.

As step S5, the control unit 40 permits the P range operation in the shift switching control unit 42, controls the operation of the parking lock 19, and proceeds to step S6. When the parking lock 19 completes its operation, it outputs parking lock operation information to the controller 40 .

In subsequent step S6, the control unit 40 acquires parking lock activation information from the activation switch of the parking lock 19, determines the P range, outputs the P range determination information to the shift selection unit 18, and returns the routine. The shift selection unit 18 acquires the P range determination information and lights the operation lamp 24 .

On the other hand, if the detection state determination unit 41 detects an abnormality related to the brake sensor 22, the determination result of step S2 becomes true (Yes), and the shift switching control unit 42 proceeds to step S7.

In step S<b>7 , the shift switching control unit 42 of the control unit 40 determines whether the vehicle 10 is stopped based on the vehicle speed V acquired from the vehicle speed sensor 23 . Specifically, as the second stopped state of the vehicle 10, it is determined whether or not the vehicle speed V has continued below the second predetermined speed V2 for a predetermined time T or longer. For example, in this embodiment, the second predetermined speed V2 is set to 0.5 km/h, and the predetermined time T is set to 2 seconds. If the determination result is true (Yes), that is, if the vehicle 10 is in the second stopped state, the process proceeds to step S5, the shift switching control unit 42 permits the P range operation as described above, and the process proceeds to step S6. to confirm the P range.

On the other hand, if the determination result in step S7 is false (No), that is, if the vehicle speed V is equal to or higher than the second predetermined speed V2, or if the vehicle speed V is less than the second predetermined speed V2, the predetermined time T is still required. If not, the shift switching control unit 42 advances the process to step S8. Further, if the determination result in step S3 or step S4 is false (No), that is, even if the brake sensor 22 is normal, the vehicle speed V is equal to or higher than the first predetermined speed V1, or the detection of the brake sensor 22 Also when the pressure Bp obtained is equal to or less than the predetermined pressure Bp1, the control unit 40 advances the process to step S8.

In step S8, the control unit 40 causes the shift switching control unit 42 not to allow the shift selection unit 18 to switch from a shift range other than the P range to the P range, and returns the routine.

As described above, according to the vehicle control device 1 according to the present embodiment, even when an abnormality related to the brake sensor 22 occurs, the vehicle 10 is determined to be in a stopped state based on the vehicle speed V, and When the stopped state continues for a predetermined time T or more, fail-safe control is performed to permit shift switching from a shift range other than the P range to the P range.

Therefore, when the brake sensor 22 is normal, it is possible to permit prompt switching to the P range based on depression of the brake pedal 22a. Even when the brake sensor 22 is abnormal, when it is confirmed from the vehicle speed V that the vehicle 10 is surely stopped, switching to the P range is permitted, so that the vehicle stops. It is possible to prevent a situation in which switching to the P range cannot be performed even though the vehicle is in the range. Then, when the P range is included in the conditions for shutting down the power generating section 11 of the vehicle 10 as in the present embodiment, the problem that the power generating section 11 cannot be shut down can be resolved.

Thus, even when there is an abnormality related to the brake sensor 22 of the vehicle, the parked state can be safely maintained.

This completes the description of the embodiment of the vehicle control device 1 according to the present invention, but the aspect of the present invention is not limited to this embodiment.

Although the brake sensor 22 of the above embodiment is a pressure sensor that detects hydraulic pressure, it may be a stroke sensor that detects the amount of depression of the brake pedal 22a. Also, the hydraulic pressure sensor and the stroke sensor may be used together, and the brake sensor itself may output an error by comparing the hydraulic pressure and the stroke inside the brake sensor. Thereby, the configuration of the control unit can be simplified.

REFERENCE SIGNS LIST 1: vehicle control device 10: vehicle 11: power generator 12: power transmission unit 13: drive shaft 14: drive wheel 15: automatic transmission 16: output shaft 17: differential mechanism 18: shift operation unit 19: parking lock 20: Accelerator opening sensor 20a: Accelerator pedal 22: Brake sensor 22a: Brake pedal 23: Vehicle speed sensor 24: Operation lamp 25: P range switch 40: Control unit 41: Detection state determination unit 42: Shift switching control unit

Claims (1)

a shift range selection unit capable of selecting at least a parking range and other shift ranges;
a brake state detection unit that detects the depression state of the brake pedal;
a vehicle speed detection unit that detects the vehicle speed of the vehicle;
When the state in which the brake pedal is depressed is detected by the brake state detection unit and the vehicle is determined to be in a stopped state from the vehicle speed detected by the vehicle speed detection unit, the parking shift range is shifted from the other shift range. a control unit that permits shift switching to the range,
When an abnormality related to the brake state detection unit is detected, the control unit determines that the vehicle is stopped based on the vehicle speed detected by the vehicle speed detection unit, and when the stop state continues for a predetermined time. , characterized by permitting shift switching from the other shift range to the parking range,
Vehicle controller.

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