JP2010006234A - Vehicle control device - Google Patents

Abstract

An object of the present invention is to satisfy a driver's braking request made during turning control.
A brake fluid pressure adjusting unit for each wheel W _FR , W _FL , W _RR , W _RL capable of adjusting brake fluid pressure supplied to braking force generating means 30 _FR , 30 _FL , 30 _RR , 30 _RL , Each pressurizing unit (pressurizing pump 69, 70) for supplying the brake fluid pressure to the brake fluid pressure adjusting unit for the pair of front wheels and the rear wheel and pressurizing the brake fluid Brake fluid pressure adjusting means 40 having one electric motor 68 for operating the unit, and controlling the brake fluid pressure adjusting means 40, the braking force is applied to at least one of the turning inner wheels during turning of the vehicle. Vehicle control means (electronic control device 2) for performing turning control for shortening or maintaining the turning radius by operating the vehicle, wherein the vehicle control means detects the driver's brake operation when the driver's brake operation is detected. Turn control is finished It is configured so that.
[Selection] Figure 1

Description

  The present invention is a vehicle capable of executing vehicle control (hereinafter referred to as “turning control”) for reducing or maintaining the turning radius by applying a braking force to at least one of the turning inner wheels during turning of the vehicle. The present invention relates to a control device.

  In general, as for the state of the vehicle during turning, a neutral steer state in which the vehicle keeps turning while maintaining a turning radius adapted to the steering angle of the steering wheel, and an over steer state in which the vehicle is caught inside the turn with respect to this neutral steer state. The vehicle is roughly divided into an understeer state in which the vehicle escapes to the outside of the turn with respect to the neutral steer state. From the viewpoint of vehicle behavior stability during turning, the neutral steer state is preferable. Conventionally, there are various vehicle control devices that control a vehicle whose behavior changes to an over steer state or an under steer state to a neutral steer state. Are known. For example, as the vehicle control device, a vehicle that may shift to an understeer state as the vehicle speed increases is controlled to the neutral steer state by performing the above-described turning control (that is, maintaining the turning radius). There is. For turning control, the braking force of at least one of the turning inner wheels is adjusted when the steering wheel is steered to the vicinity of the steering limit in a predetermined vehicle speed range (for example, an extremely low speed range such as about 15 km / h or less). Some are executed by The turning control at this time is one that can forcibly reduce the predetermined minimum turning radius according to the specification values of the vehicle wheelbase, etc. (that is, the small turning control that can improve the turning ability). is there. In this small turning control, the braking force of the turning inner wheel is adjusted according to the accelerator opening during the control, and when the steering angle of the steering wheel is returned or deviated from the predetermined vehicle speed range (when the vehicle stops or the predetermined vehicle speed range). When it ’s faster). For example, Patent Documents 1 and 2 below disclose that a small turning control is performed by applying a braking force to a turning inner wheel on the front side in the traveling direction during turning of the vehicle, thereby generating a yaw moment in the vehicle. . On the other hand, Japanese Patent Application Laid-Open No. H10-228667 discloses a device that performs a small turning control by applying a braking force to a turning inner wheel on the rear side in the traveling direction during turning of the vehicle, thereby generating a yaw moment in the vehicle.

Japanese Patent Laid-Open No. 11-49019 Japanese Patent No. 2576118 JP 11-49020 A

  By the way, in this type of vehicle control device, a braking device is used to perform small turn control. The braking device in this case includes a brake fluid pressure adjusting means capable of adjusting the brake fluid pressure (hereinafter referred to as “brake fluid pressure”) to the braking force generating means (wheel cylinder and caliper) of each wheel. Is provided. The brake fluid pressure adjusting means has a brake fluid pressure adjusting unit including a holding valve and a pressure reducing valve for each wheel. In this braking device, a common first brake fluid pressure is supplied to the upstream portions of the respective brake fluid pressure regulating portions of the right front wheel and the left rear wheel, and each of the left front wheel and the right rear wheel. There is a type having a brake hydraulic pressure circuit called a so-called X pipe in which a common second brake hydraulic pressure is supplied to an upstream portion of the brake hydraulic pressure adjusting portion. In the braking device having the brake fluid pressure circuit of X piping, one pressure pump that operates using one electric motor as a drive source is used for generating the first brake fluid pressure and for generating the second brake fluid pressure. They are arranged one by one. In a vehicle equipped with a braking device having a brake hydraulic pressure circuit for X piping, the above-described small turning control is executed by adjusting the braking force of at least one of the turning inner wheels.

  For example, when small turn control is performed by adjusting the braking force of any one of the turning inner wheels, the pressurizing pump of the brake hydraulic circuit system (control system) having the wheel for which the braking force is to be generated And the brake fluid pressure adjusting unit of the wheel is released (that is, controlled to the pressure increasing mode) to supply the brake fluid pressure of the upstream portion to the braking force generation means of the wheel, The brake fluid pressure adjusting portion of the turning outer wheel is shut off (that is, controlled to the holding mode) so that the upstream brake fluid pressure is not supplied to the braking force generating means of the turning outer wheel. At that time, the pressure pump of the brake hydraulic circuit system (non-control system) having the other turning inner wheel that is not subject to the generation of braking force is idled, and the other turning inner wheel and the turning of the same system as the turning inner wheel are turned on. The brake fluid pressure in the upstream portion of each brake fluid pressure adjusting portion of the outer ring is prevented from being increased. That is, in this case, the braking force acts only on one turning inner wheel of the control system, and no braking force acts on the remaining three wheels.

  Here, the brake fluid pressure adjusting portions of the turning inner wheel and the turning outer wheel of the non-control system are controlled to the pressure increasing mode, and the respective upstream portions thereof communicate with the respective braking force generating means of the turning inner wheel and the turning outer wheel. To open. It is assumed that the driver performs a brake operation during the turning control in this case. At this time, a braking force according to the brake operation is applied to the turning inner wheel and the turning outer wheel of the non-control system, but the holding outer turning wheel in the same system relationship with the turning inner wheel of the control system corresponds to the braking operation. The braking force is not applied. Therefore, at this time, the actual vehicle braking force may be insufficient with respect to the driver's requested vehicle braking force.

  In addition, if the driver performs a braking operation during turning control when there is a failure in the non-control system, the braking force of the turning inner wheel and the turning outer wheel of the non-control system is insufficient with respect to the driver's required value. there's a possibility that. Therefore, at this time, there is a possibility that the actual vehicle braking force may be insufficient with respect to the driver's requested vehicle braking force due to the insufficient braking force of the turning inner wheel and the turning outer wheel of the non-control system.

  Accordingly, an object of the present invention is to provide a vehicle control device that improves the disadvantages of the conventional example and satisfies the driver's braking request made at the time of turning control.

  In order to achieve the above object, according to the first aspect of the present invention, the brake fluid pressure regulating unit for each wheel capable of regulating the brake fluid pressure supplied to the braking force generating means, the brake fluid is pressurized and the pressure is increased. Brake fluid pressure adjusting means including a pair of pressurizing units for supplying brake fluid pressure to a pair of front and rear brake fluid pressure regulating units, and one electric motor for operating each of the pressurizing units, and the brake Vehicle control means for performing turning control for shortening or maintaining the turning radius by applying a braking force to at least one of the turning inner wheels during turning of the vehicle by controlling the hydraulic pressure adjusting means. In the vehicle control device, the vehicle control means is configured to end the turning control when the driver's brake operation is detected.

  Since the vehicle control apparatus according to the first aspect of the present invention can perform normal braking control by ending the turning control, the requested vehicle braking force according to the driver's braking operation can be applied to the vehicle.

  Here, the vehicle control means is configured to delay the end timing of the turn control as the driver's brake operation amount is smaller, as in the second aspect of the invention. Thus, when the driver's brake operation amount is large and the requested vehicle braking force is large, the turning control is switched to the normal braking control at an early stage. On the other hand, when the amount of brake operation by the driver is small and the required vehicle braking force is small, it takes time to switch from turning control to normal braking control. Therefore, the required vehicle braking force is applied to the vehicle at the time that the driver intends.

  In the vehicle control device according to the present invention, if the driver performs a brake operation during the turn control, the turn control is terminated and the normal braking control can be executed. For this reason, the vehicle control device can apply a vehicle braking force according to the driver's brake operation to the vehicle, and can satisfy the driver's braking request.

  Embodiments of a vehicle control device according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example 1]
A vehicle control apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

  The vehicle control apparatus according to the first embodiment mainly includes a braking device 1 that is operated when vehicle control (turning control) is performed, and vehicle control that executes vehicle control (turning control) by operating the braking device 1. And an electronic control unit (ECU) 2 as means.

  The turning control is the small turning control described above, and when a steering wheel (not shown) is steered to the vicinity of the steering limit in a predetermined vehicle speed range (for example, an extremely low speed range such as about 15 km / h or less), It is executed by adjusting the braking force of at least one of the wheels. In a two-wheel drive vehicle, as a rule, the braking force of the driven wheel that is the turning inner wheel is adjusted. However, the braking force of the driving wheel that is the turning inner wheel or the braking force of both the turning inner wheels is adjusted. The turning control may be performed accordingly. In a four-wheel drive vehicle, the braking force of both the front and rear turning inner wheels is adjusted in principle, but turning control is performed by adjusting the braking force of one of the turning inner wheels. Also good.

  The electronic control unit 2 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores a predetermined vehicle control program in advance, and a RAM (Random Access Memory) that temporarily stores the calculation results of the CPU. , And a backup RAM for storing information prepared in advance.

On the other hand, the braking device 1 of the first embodiment has the so-called X-pipe brake hydraulic pressure circuit described above, and the braking force is individually applied to each of the wheels W _FR , W _FL , W _RR , W _RL . It is comprised so that it can generate | occur | produce.

The braking device 1 includes a brake fluid pressure generating means 20 that generates a brake fluid pressure corresponding to the amount of operation of the brake pedal 10 by the driver, and each wheel W that generates a braking force when supplied with the brake fluid pressure. Braking force generating means (wheel cylinder and caliper) 30 _FR , 30 _FL , 30 _RR , 30 _RL for each of _{FR 1} , W _FL , W _RR , W _RL and the brake fluid pressure generated by the brake fluid pressure generating means 20 are used as they are. or the wheels _{W FR,} and _{W FL,} W RR, W tone for each _RL pressure in each of the braking force generating means _{30 FR, 30 FL, 30 RR} , 30 brake fluid pressure adjusting means 40 for supplying the _RL, is provided ing.

  First, the brake fluid pressure generating means 20 includes a brake boosting means (brake booster) 21 for doubling an operation pressure (pedal pressing force) accompanying the brake operation of the driver input to the brake pedal 10 by a predetermined boost ratio. The master cylinder 22 for converting the pedal depression force doubled by the brake boosting means 21 into a brake fluid pressure (hereinafter referred to as “master cylinder pressure”) corresponding to the operation amount of the brake pedal 10, and the brake fluid And a reservoir tank 23 for storing.

Here, two hydraulic chambers (not shown) are provided inside the master cylinder 22, and the master cylinder pressure is generated in each of the hydraulic chambers. Its master cylinder pressure generated in the hydraulic chamber of each is one being fed to the right front wheel W _FR and the left rear wheels W _RL via the first brake fluid pressure circuit system to be described later of the brake fluid pressure adjusting means 40, the other There is supplied to the left front wheel W _FL and the right rear wheel W _RR through the second brake fluid pressure circuit system to be described later of the brake fluid pressure adjusting means 40. Accordingly, in the braking device 1 of the first embodiment, the first and second hydraulic pressure chambers having one end connected to the respective hydraulic chambers and the other ends connected to the first brake hydraulic circuit system and the second brake hydraulic circuit system, respectively. Second hydraulic pipes 24 and 25 are provided.

Next, the brake fluid pressure adjusting means 40 adjusts the brake fluid pressure (master cylinder pressure) in the first and second hydraulic pipes 24 and 25 as they are or adjusts the respective brake force generating means 30 _FR and 30. It is a so-called brake actuator that supplies _FL , _30RR , and _30RL . The brake fluid pressure adjusting means 40 operates according to a control command of the brake fluid pressure control means of the electronic control device 2.

The brake fluid pressure adjusting means 40 of the first embodiment includes a first brake fluid pressure circuit system that transmits brake fluid pressure to the right front wheel _WFR and the left rear wheel _WRL , and the left front wheel _WFL and right rear wheel _WRR. The second brake fluid pressure circuit system that transmits the brake fluid pressure to the vehicle is illustrated as an example. That is, this brake fluid pressure adjusting means 40 has a structure having a brake fluid pressure circuit of X piping. Here, the first brake hydraulic circuit system is connected to the first hydraulic pipe 24, while the second brake hydraulic circuit system is connected to the second hydraulic pipe 25.

  The brake fluid pressure adjusting means 40 is provided with a master cylinder pressure sensor 41 that detects the brake fluid pressure (that is, master cylinder pressure) supplied from the brake fluid pressure generating means 20. The master cylinder pressure sensor 41 is arranged in one of the first or second hydraulic pipes 24 and 25 and transmits a detection signal to the electronic control unit 2. Here, the master cylinder pressure sensor 41 is illustrated as being provided in the first hydraulic pipe 24.

The brake fluid pressure adjusting means 40 includes master cut valves 42 and 43 as flow rate adjusting means for the respective brake fluids in the first and second brake fluid pressure circuit systems. Here, a master cut valve 42 is disposed downstream of the master cylinder pressure sensor 41. Each of these master cut valves 42 and 43 is a so-called normally-open flow rate adjusting electromagnetic valve that is normally in an open state, and controls the opening of the valve in accordance with energization by the brake fluid pressure control means of the electronic control unit 2. Is executed. That is, the master cut valves 42 and 43 adjust the pressure of brake fluid discharged from pressurizing pumps 69 and 70, which will be described later, by controlling the valve opening according to the energization amount to the master cylinder 22 side. Open. In addition, the downstream shown in the first embodiment is a downstream side in the flow direction of the brake fluid when the pedal is operated (that is, the direction toward the braking force generating means 30 _FR , 30 _FL , 30 _RR , 30 _RL ). .

Here, in the brake fluid pressure adjusting means 40, the first hydraulic pipe 24 is connected to the connecting passage 44 via the master cut valve 42, while the second hydraulic pipe 25 is connected to the connecting passage via the master cut valve 43. 45. Then, two branch passages 46 and 47 are connected to the connection passage 44 of the first brake hydraulic circuit system so as to branch from there, and the connection passage 45 of the second brake hydraulic circuit system is connected thereto from there. Two branch passages 48 and 49 are connected so as to be branched. In the first brake fluid pressure circuit system, connected to the hydraulic pipe _{31 RL} of hydraulic pipe _{31 FR} and the left rear wheels _{W RL} of the right front wheel _{W FR} branch passages 46, 47 of each, respectively. On the other hand, in the second brake fluid pressure circuit system, connected to the hydraulic pipe _{31 FL} of hydraulic pipe _{31 RR} and the left front wheel _{W FL} of the right rear wheel _{W RR} branch passages 48 and 49 each respectively.

Further, the on the branch passages 46, 47, 48, 49, respectively of the braking force generating means _{30 FR, 30 FL, 30 RR} , 30 adjustable brake fluid pressure adjusting pressure section of the brake fluid pressure for each _RL is It is disposed for each of the wheels _WFR , _WFL , _WRR , _WRL . Brake fluid pressure adjusting pressure section of the respective the wheel _{W FR, W FL, W RR} , W RL holding valves 50, 51, 52, 53 and the brake fluid prepared for each pressure discharge passage 54, 55, 56, 57 And pressure reducing valves 58, 59, 60, 61. Here, holding valves 50, 51, 52, 53 are provided on the respective branch passages 46, 47, 48, 49, and further brakes are provided downstream of these holding valves 50, 51, 52, 53. The hydraulic pressure discharge passages 54, 55, 56 and 57 are connected so as to be branched from the branch passages 46, 47, 48 and 49, respectively. On the brake fluid pressure discharge passages 54, 55, 56 and 57, pressure reducing valves 58, 59, 60 and 61 are respectively provided.

  Each of the holding valves 50, 51, 52, 53 is a so-called normally-open electromagnetic valve, and is normally open in a non-excited state and is energized by the brake fluid pressure control means of the electronic control unit 2. Along with this, the excited state is entered and the valve is closed. On the other hand, each of the pressure reducing valves 58, 59, 60, 61 is a so-called normally closed solenoid valve, which is normally closed in a non-excited state and is in an excited state in response to energization by the brake fluid pressure control means. It is something that can be said.

  Further, here, the brake hydraulic pressure discharge collecting passage 62 that brings together the brake hydraulic pressure discharge passages 54 and 55 of the first brake hydraulic pressure circuit system, and the brake hydraulic pressure discharge of the second brake hydraulic pressure circuit system. A brake hydraulic pressure discharge collecting passage 63 is provided which brings the passages 56 and 57 together, and the brake hydraulic pressure discharge collecting passages 62 and 63 are connected to auxiliary reservoirs 64 and 65, respectively.

  Further, in the first brake fluid pressure circuit system, a pump passage 66 branched from a branch point between the connection passage 44 and each of the branch passages 46 and 47 and connected to the brake fluid pressure discharge collecting passage 62 is provided. Similarly, in the second brake hydraulic circuit system, a pump passage 67 branched from the branch point between the connecting passage 45 and the branch passages 48 and 49 and connected to the brake hydraulic pressure discharge collecting passage 63 is provided. To do.

The pump passages 66 and 67 are respectively provided with pressurizing pumps (pressurizing units) 69 and 70 driven by one electric motor 68. Each of these pressurizing pumps 69 and 70 discharges the brake fluid toward the respective branch points on the master cut valves 42 and 43 side, and respectively with respect to the branch passages 46 and 47 and the branch passages 48 and 49. To supply the brake fluid pressure. That is, the pressurizing pump 69 of the first brake hydraulic circuit system supplies the braking force generation means 30 _FR and 30 _RL to increase the braking force generated on the right front wheel W _FR and the left rear wheel W _RL. Increase brake fluid pressure. On the other hand, the pressurizing pump 70 of the second brake hydraulic circuit system supplies the braking force generating means 30 _FL and 30 _RR to increase the braking force generated on the left front wheel W _FL and the right rear wheel W _RR. Increase brake fluid pressure. The electric motor 68 is driven by power supply from a battery (not shown). In addition, damper chambers 71 and 72 for avoiding the pulsation of the brake fluid discharged from the pressurizing pumps 69 and 70 are disposed in the pump passages 66 and 67, respectively.

  The brake fluid pressure adjusting means 40 is provided with intake passages 73 and 74 that are branched from the first and second hydraulic pipes 24 and 25 and connected to the auxiliary reservoirs 64 and 65, respectively. Further, reservoir cut check valves 75 and 76 are disposed on the auxiliary reservoirs 64 and 65 side of the respective suction passages 73 and 74.

  The operation of the braking device 1 of the first embodiment configured as described above is controlled by the electronic control device 2 as described above.

  Specifically, the electronic control unit 2 includes an operation amount of the brake pedal 10 detected by the brake pedal operation amount detection means 11 shown in FIG. 1 and a master cylinder pressure detected by the master cylinder pressure sensor 41. Entered. That is, the electronic control device 2 receives the brake pedal operation amount detected when the driver makes a braking request by operating the brake pedal 10 and the master cylinder pressure generated by the operation. . Here, for example, the amount of operation of the brake pedal 10 includes the amount of depression of the brake pedal 10 and the pedal depression force. For this reason, the brake pedal operation amount detection means 11 may be a pedal stroke sensor or a pedal depression force sensor.

In this electronic control unit 2, the driver's requested vehicle braking force is calculated based on the operation amount of the brake pedal 10. For example, the required vehicle braking force is obtained by a calculation method known in this technical field. The brake fluid pressure control means of the electronic control unit 2 is configured so that the required vehicle braking force acts on the vehicle by the sum of the braking forces of all the wheels _WFR , _WFL , _WRR , _WRL. The adjusting means 40 is controlled.

Here, if the required vehicle braking force can be generated without driving the pressurizing pumps 69, 70, in other words, if the required vehicle braking force can be generated by the master cylinder pressure, the brake fluid can be generated. The pressure control means stops the pressurizing pumps 69 and 70 by stopping the electric motor 68. The brake fluid pressure control means, for example, the behavior of the vehicle based on the master cylinder pressure, the brake pedal operation amount, and the state of the vehicle (the slip rate of the wheels _WFR , _WFL , _WRR , _WRL , etc.). The master cut valves 42, 43 and the holding valve 50 so that the required vehicle braking force acts on the vehicle by the sum of the braking forces of the wheels _WFR , _WFL , _WRR , _WRL while keeping the vehicle in a stable state. 51, 52, 53 and pressure reducing valves 58, 59, 60, 61 are controlled.

At this time, for example, in the pressure increasing mode for increasing the brake fluid pressure, the master cut valves 42 and 43 and the holding valves 50, 51, 52 and 53 are opened, while the pressure reducing valves 58, 59, 60 and 61 are opened. Is closed. As a result, each of the braking force generation means 30 _FR , 30 _FL , 30 _RR , 30 _RL has a brake fluid pressure that is increased until the required vehicle braking force is satisfied while the vehicle behavior is stabilized (at most, the master cylinder). Pressure). Further, for example, when the brake pedal operation amount becomes small, the master cylinder pressure decreases, so that the master cut valves 42, 43 and the holding valves 50, 51, 52, 53 are closed, while the pressure reducing valves 58, 59, 60 are closed. , 61 are switched to a pressure reduction mode. As a result, the brake fluid pressure (the reduced master cylinder pressure) is applied to each of the braking force generation means 30 _FR , 30 _FL , 30 _RR , 30 _RL until the required vehicle braking force is satisfied. Is supplied. In addition, after the brake fluid pressure of each braking force generating means 30 _FR , 30 _FL , 30 _RR , 30 _RL has been increased or decreased, the master cut valves 42, 43, the holding valves 50, 51, 52, 53 and the pressure reducing valves 58, 59, 60, 61 are closed to switch to a holding mode in which the brake fluid pressure is held. It should be noted that the brake fluid pressure corresponding to the requested vehicle braking force is distributed to each of the braking force generating means 30 _FR , 30 _FL , 30 _RR , 30 _RL at a predetermined or distribution ratio according to the vehicle state.

In the first embodiment, the “reference vehicle braking force” is the sum of the braking forces of the wheels W _FR , W _FL , W _RR , W _RL generated without driving the pressurizing pumps 69, 70 as described above. That's it.

On the other hand, in the braking device 1, even if the reference vehicle braking force is generated with the maximum magnitude, the reference vehicle braking force may not satisfy the required vehicle braking force. That is, there are cases where the requested vehicle braking force cannot be generated in the vehicle only with the reference vehicle braking force based on the master cylinder pressure. Therefore, the brake fluid pressure control means of the electronic control unit 2 in this case is based on the brake pedal operation amount, the master cylinder pressure, and the vehicle state, and the master cut valves 42, 43 and the holding valves 50, 51, 52, 53. a pressure reducing valve 58, 59, 60, 61 become not motor 68 also drives and controls only, while stabilizing the behavior of the vehicle wheels _{W FR, W FL, W RR} , requested vehicle braking to the vehicle by the braking force of the _{W RL} Let the power work. Specifically, the brake fluid pressure control means opens the holding valves 50, 51, 52, 53, and closes the master cut valves 42, 43 and the pressure reducing valves 58, 59, 60, 61, and the lack thereof. The electric motor 68 and the pressure pumps 69 and 70 are driven so that a vehicle braking force corresponding to the minute (hereinafter referred to as “differential pressure vehicle braking force”) is generated. That is, here, the master cut valves 42 and 43, the electric motor 68, and the pressure pumps 69 and 70 are set so that the brake fluid is pressurized with a pressurization amount (that is, discharge amount or discharge pressure) corresponding to the shortage. By driving, a differential pressure vehicle braking force corresponding to the amount of pressurization is applied to each wheel W _FR , W _FL , W _RR , W _RL at a predetermined or distribution ratio according to the vehicle state. As a result, the required vehicle braking force obtained by combining the reference vehicle braking force and the differential pressure vehicle braking force is applied to the vehicle.

Further, in the braking device 1 of the first embodiment, the brake fluid pressure is individually applied to at least one of the braking force generation means 30 _FR , 30 _FL , 30 _RR , 30 _RL selected as a control target. Can also be supplied. For example, this is the case when the above-described turning control (small turn control) is performed. Here, the turning control at the time of turning right in an FF (front engine / front drive) vehicle will be described as an example. Thus, here, illustrated as the turning control is performed by the adjustment of the braking force of the serving turning inner traveling direction rear right rear wheel W _RR. Here, the brake fluid pressure control at the time of turning control execution may be executed by the brake fluid pressure control means, but in the following, it is exemplified as being executed by the vehicle control means.

When performing turning control during right turning, the vehicle control means of the electronic control unit 2 generates the only braking force to the right rear wheel W _RR as a turning inner traveling direction rear side. Therefore, the vehicle control means in this case drives the electric motor 68 when the turning control execution condition is satisfied, makes the first brake hydraulic circuit system a non-control system, and the right rear wheel W _RR thereof. The drive control of the master cut valves 42, 43, etc. is performed using the second brake hydraulic circuit system including the control system as a control system. The execution condition of the turning control is, for example, that the steering angle of the steering wheel detected by the steering angle detection unit 81 shown in FIG. 1 has reached a predetermined steering limit and is detected by the vehicle speed detection unit 82. The vehicle speed is within a predetermined vehicle speed range. The steering angle detection means 81 and the vehicle speed detection means 82 are so-called steering angle sensors, vehicle speed sensors, and the like, and any of those known in the technical field can be applied.

In the second brake hydraulic circuit system as a control system, the vehicle control means drives the pressurizing pump 70 and controls the master cut valve 43 and the holding valve 53 for the left front wheel _WFL to be in an excited state as shown in FIG. and, and, and it controls the holding valve 52 and pressure reducing valve 60, 61 of each of the right rear wheel _{W RR} and a left front wheel _{W FL} of the right rear wheel _{W RR-energized} state. Thereby, in the second brake hydraulic circuit system, the pressurizing pump 70 sucks the brake fluid from the master cylinder 22 and pressurizes it. Further, in this second brake hydraulic circuit system, the valve opening of the master cut valve 43 is narrower than the valve opening state of FIG. 1 according to the accelerator opening by the driver detected by the accelerator opening detecting means 83. while being controlled in the direction, the holding valve 52 of the right rear wheel _{W RR} is in the open state, and the holding valve 53 and the pressure reducing valves 60, 61 of the left front wheel _{W FL} is in a closed state. That is, the brake fluid pressure adjusting pressure portion in the second brake fluid pressure circuit system, while those of the right rear wheel W _RR is controlled to the pressure increasing mode, that of the left front wheel W _FL is controlled to the hold mode. This because, in the second brake fluid pressure circuit system, the pressurized braking force generating means of the right rear wheel W _RR by the brake fluid pressure 30 _RR brake fluid pressure is boosted is the right rear wheel W _RR Only the braking force is generated, and the brake fluid pressure of the braking force generating means 30 _FL of the left front wheel _WFL is kept constant (braking force = 0). At that time, the braking force applied to the right rear wheel _WRR is adjusted to a magnitude corresponding to the accelerator opening.

Further, the vehicle control means prevents the brake fluid pressure from being increased by causing the pressure pump 69 to idle in the first brake fluid pressure circuit system which is a non-control system, and as shown in FIG. The holding valves 50 and 51 and the pressure reducing valves 58 and 59 are controlled to be in a non-excited state. Thereby, in the first brake hydraulic circuit system, the master cut valve 42 and the holding valves 50 and 51 are opened, and the pressure reducing valves 58 and 59 are closed. That is, the brake fluid pressure adjusting pressure section of the first brake fluid pressure circuit system is also respectively controlled to the pressure increasing mode that also left rear wheels W _RL those of the right front wheel W _FR. At this time, in the first brake hydraulic circuit system, the brake hydraulic pressure is not increased by the pressurizing pump 69 and the driver does not perform the brake operation, so the right front wheel _WFR and the left The brake fluid pressure generating means 30 _FR , 30 _RL of the rear wheel W _RL is kept constant (braking force = 0).

  In the vehicle, the turning control is performed on the brake fluid pressure adjusting means 40 to generate a yaw moment, and the turning radius corresponding to the steering angle of the steering wheel can be maintained. It is also possible to turn with a turning radius smaller than the turning radius, and the turning ability is improved.

This turning control is performed when the turning control end condition is satisfied, that is, when the steering angle of the steering wheel is returned or when the vehicle deviates from the predetermined vehicle speed range (when the vehicle stops or becomes faster than the predetermined vehicle speed range). To finish. For this reason, even if the driver performs a brake operation during the turn control, the turn control is not finished until the turn control end condition is satisfied. Therefore, the brake fluid of each wheel W _FR , W _FL , W _RR , W _RL The pressure regulating unit is maintained in the control mode described above. Accordingly, the master cylinder pressure corresponding to the operation amount of the brake pedal 10 (detected by the brake pedal operation amount detection means 11) is applied to the right front wheel _WFR and the left rear wheel _WRL until the turning control end condition is satisfied. In addition to the respective braking force generating means 30 _FR and 30 _RL , it is also applied to the braking force generating means 30 _RR of the right rear wheel W _RR depending on the valve opening degree of the master cut valve 43. That is, at that time, the braking force accompanying the brake operation of the driver is applied to the right front wheel _WFR and the left rear wheel _WRL of the non-control system, and the driver is applied to the right rear wheel _WRR of the control system. The braking force associated with the braking operation and the braking force associated with the turning control are applied. On the other hand, in the left front wheel W _FL of a control system brake fluid pressure regulating pressure section is controlled in the holding mode, the master cylinder pressure is not applied to the braking force generating means 30 _FL, it is impossible to generate a braking force. Therefore, in this case, there is a possibility that the actual vehicle braking force is insufficient with respect to the required vehicle braking force accompanying the driver's braking operation. That is, during turning control in which braking force is applied to one of the turning inner wheels, when the driver performs a braking operation, the braking force is applied to the turning outer wheel in the same system as that wheel and in the holding mode. May not be generated, and the actual vehicle braking force may not reach the driver's requested vehicle braking force.

  Here, a case where the turning control is performed by applying a braking force to both the turning inner wheels on the front and rear sides is also considered. In this case, when the driver performs a brake operation, it becomes impossible to generate a braking force on each turning outer wheel in the same system as each turning inner wheel and in the holding mode. For this reason, in this case, there is a high possibility that the actual vehicle braking force is further insufficient with respect to the driver's requested vehicle braking force.

Therefore, the vehicle control device of the first embodiment is configured to satisfy the driver's braking request made during the turning control. Therefore, if the driver's brake operation is detected during the turn control, the turn control is terminated in the vehicle control means of the vehicle control apparatus of the first embodiment. Then, after the end, normal braking control by the brake fluid pressure control means is executed. The normal braking control referred to here is a braking control executed by the brake hydraulic pressure control means in order to stop or decelerate the vehicle according to the driver's braking operation. In addition to braking control during non-driving or driving, for example, ABS control that repeats the pressure increasing mode and the pressure reducing mode while monitoring the lock state and slip state of the wheels W _FR , W _FL , W _RR , W _RL and the like is included.

  Here, the electronic control device 2 according to the first embodiment is provided with a brake operation detecting unit that detects a driver's brake operation. The brake operation detection means includes, for example, when a change in the master cylinder pressure received from the master cylinder pressure sensor 41 is detected when a detection signal (brake pedal operation amount) from the brake pedal operation amount detection means 11 is received or When the input signal of the stop lamp switch 84 shown in FIG. 1 is detected, it is determined that the brake operation has been performed by the driver. The stop lamp switch 84 is an input switch of a stop lamp (not shown) that is lit in conjunction with the driver's brake operation.

  Further, the driver's brake operation is not necessarily performed with the same brake pedal operation amount. For this reason, unless the turning control is terminated in accordance with the required vehicle braking force according to the driver's braking operation (for example, after detecting the driver's braking operation, the turning control is instantaneously ended and the normal braking control is performed). When switched, the actual vehicle deceleration deviates from the driver's requested vehicle deceleration, which gives the driver a feeling of strangeness. Therefore, the vehicle control means of the first embodiment sets the end timing of the turning control according to a value indicating the state of the brake operation of the driver (hereinafter referred to as “brake operation state value”). For example, as the brake operation state value, a brake pedal operation amount, a master cylinder pressure, a driver's requested vehicle braking force, or the like may be used. Here, as the brake operation state value is smaller, that is, as the brake pedal operation amount, the master cylinder pressure, the required vehicle braking force, and the like are smaller, the turn control end time is delayed. The correspondence relationship between the brake operation state value and the end time of the turning control is set in advance through experiments and simulations so that the driver does not feel uncomfortable. 3 and 4 show the end timings of the turning control when the master cylinder pressure is large and small, respectively. FIG. 3 shows a wheel that is a control system during turning control, and FIG. 4 shows a wheel that is a non-control system during turning control.

  For wheels that are subject to braking force generation during turning control, the wheel braking force at the end of turning control when master cylinder pressure is also applied and the required wheel braking force required for normal braking control There is a difference between For this reason, if the turning control is instantaneously switched to the normal braking control just because the end time of the turning control is reached, the driver feels uncomfortable due to a large change in the vehicle deceleration. Therefore, in the vehicle control means of the first embodiment, the differential pressure between the upstream side and the downstream side of the master cut valves 42 and 43 whose valve opening degree is adjusted during the turning control is controlled as shown in FIG. Gradually disappear towards the end time. That is, the vehicle control means gradually controls the valve opening degrees of the master cut valves 42 and 43 to the valve open state (non-excitation state).

  Hereinafter, an example of the operation during the turning control (small turning control) in the vehicle control apparatus of the first embodiment will be described based on the flowchart of FIG.

  First, the electronic control unit 2 according to the first embodiment determines whether or not the turning control is being performed based on, for example, the control command content for the brake fluid pressure adjusting means 40 (step ST5).

  When it is determined that the turning control is being performed, the brake operation detecting means of the electronic control device 2 determines whether or not the driver has operated the brake (step ST10). This determination is made based on the detection signal of the brake pedal operation amount detection means 11 as described above.

  Here, if it is determined that the brake operation has been performed, the vehicle control means of the electronic control device 2 sets the end time of the turn control according to the brake operation state value described above (step ST15). Then, the vehicle control means ends the turn control in accordance with the end time of the turn control (step ST20). At the end, the vehicle control means passes the control body of the brake fluid pressure adjusting means 40 to the brake fluid pressure control means. The brake fluid pressure control means performs normal braking control based on the driver's brake pedal operation amount and the like (step ST25).

For example, here, the above-described case where only the right rear wheel _WRR is the wheel for which the braking force is generated (the wheel for turning control) at the time of turning control is illustrated. In this case, when the vehicle control means detects the driver's brake operation during the turn control, in step ST15, for example, the lower the master cylinder pressure, the later the end time of the turn control is set. At that time, the vehicle control means controls the master so that the differential pressure between the upstream side and the downstream side of the master cut valve 43 of the control system gradually disappears toward the end timing of the turning control as shown in FIG. The indicated pressure of the cut valve 43 is also set. In step ST20, the vehicle control unit performs turn control end control by controlling the master cut valve 43 with the command pressure. Thus, the turning control ends at the set end time. During the end control period of the turning control, the braking fluid pressure generating means 30 _{RR of the} right rear wheel W _{RR that} is the turning control target wheel is a brake fluid pressure that is a sum of the differential pressure of the master cut valve 43 and the master cylinder pressure. To join. The brake fluid pressure gradually approaches the master cylinder pressure as the turning control end time approaches, and reaches the same magnitude as the master cylinder pressure at the turning control end time. On the other hand, for the wheels of the non-control system (the right front wheel _WFR and the left rear wheel _WRL ), the master cut valve 42 is in a non-excited state, and each brake fluid pressure adjusting unit is in the pressure increasing mode. Therefore, as shown in FIG. 4, the master cylinder pressure acts as the brake fluid pressure to the respective braking force generation means 30 _FR and 30 _RL . Therefore, a braking force corresponding to the driver's braking operation is applied to the wheels of the non-control system.

After the turn control is completed, for example, the brake fluid pressure control means, in step ST25, the master cylinder pressure, the brake pedal operation amount, and the vehicle state (the slip ratio of the wheels _WFR , _WFL , _WRR , _WRL , etc.) Based on the above, the master cut valves 42, 43 and the holding valves 50, 51, 52, 53 are controlled to be opened, and the pressure reducing valves 58, 59, 60, 61 are controlled to be closed. In this example, in the first brake hydraulic circuit system that was a non-control system at the time of turning control, the master cut valve 42, the holding valves 50 and 51, and the pressure reducing valves 58 and 59 are kept in the state at the time of turning control. Be drunk. On the other hand, in the second brake fluid pressure circuit system which was a control system, together with the holding valve 53 of the master cut valve 43 and the turning outer wheel serving left front wheel W _FL is switched to the open state, the right rear wheel W _RR holding valve 52 In addition, the pressure reducing valve 60 and the pressure reducing valve 61 of the left front wheel _WFL maintain the state during the turning control. That is, the brake fluid pressure adjusting means 40 is switched from the turning control state shown in FIG. 2 to the pressure increasing mode state shown in FIG. This reason, the braking force generating means 30 _RR of the right rear wheel W _RR, (may be a brake hydraulic pressure pressurized by the pressurizing pump 70) the master cylinder pressure as shown in FIG. 3 continues added. On the other hand, for the braking force generating means 30 _{FL of the} left front wheel W _FL that is the non-turning control target wheel of the control system, as shown in FIG. 3, the master cylinder pressure (the brake hydraulic pressure pressurized by the pressure pump 70 may be used). ) Until the brake fluid pressure is increased. Further, the braking force generating means of the wheels of the non-control system (front-right wheel _{W FR} and the left rear wheel _W braking force generating means _{RL 30} FR, _{30 RL),} as shown in FIG. 4, the end control of the turning control The master cylinder pressure is continuously applied. Therefore, in this case, a braking force corresponding to the driver's braking operation is applied to the wheels W _FR , W _FL , W _RR , W _RL , and the driver's requested vehicle braking force acts on the vehicle.

  Here, when it is determined in step ST5 that the turning control is not being performed, or when it is determined in step ST10 that the driver is not performing a brake operation, the electronic control unit 2 once ends this calculation process. Return to step ST5.

  As described above, when the vehicle control device of the first embodiment detects the driver's brake operation during the turn control, the turn control is finished and the normal brake control is switched to give priority to the driver's intention. . In other words, the vehicle control device switches to the pressure-increasing mode to generate the braking force for the wheels that are controlled in the holding mode during the turning control. For this reason, the vehicle control device can apply the vehicle braking force requested by the driver to the vehicle.

  In addition, the vehicle control device sets the end time of the turn control according to the brake operation state value. Thus, when the driver's brake operation amount is large and the requested vehicle braking force is large, the turning control is switched to the normal braking control at an early stage. On the other hand, when the amount of brake operation by the driver is small and the required vehicle braking force is small, it takes time to switch from turning control to normal braking control. For this reason, the required vehicle braking force is applied to the vehicle at the time intended by the driver.

  In addition, this vehicle control device smoothly shifts the brake fluid pressure of the turning control target wheel from the magnitude at the time of turning control to the master cylinder pressure (or the brake fluid pressure pressurized by the pressure pump 69 (70)). It is set as follows. For this reason, the vehicle control device can prevent a sudden change in the vehicle braking force.

  As described above, the vehicle control apparatus according to the first embodiment can satisfy the driver's braking request by applying the vehicle braking force required by the driver to the vehicle at an appropriate magnitude and timing. In other words, the vehicle control device can prevent the driver from feeling uncomfortable by preventing the difference between the actual vehicle deceleration and the driver's requested vehicle deceleration.

  Here, when performing turn control in which both the front and rear turning inner wheels are turning control target wheels and both the front and rear turning outer wheels are non-turning control target wheels, two wheels are in the holding mode during turning control. Therefore, the above-described effect is remarkably exhibited.

[Example 2]
Next, a second embodiment of the vehicle control device according to the present invention will be described with reference to FIG.

  In the second embodiment, the vehicle of the first embodiment described above is illustrated as an application target of the vehicle control device.

  For example, when the non-control system having the master cylinder pressure sensor 41 in the vehicle (in the example of the first embodiment, the first brake hydraulic circuit system) fails, the driver performs the brake operation during the turn control. Even if it goes, there is a possibility that the braking force of the wheels of the non-control system will be insufficient for the driver's request. When the brake operation is executed, the braking force by the brake fluid pressure during the turn control and the brake fluid pressure accompanying the brake operation is applied to the turning control target wheels of the control system. On the other hand, since the non-turning control target wheel of the control system is controlled in the holding mode, the braking force does not work. Therefore, in this case, the actual vehicle braking force may be insufficient with respect to the driver's requested vehicle braking force.

  Therefore, when there is a failure in the non-control system, the vehicle control device according to the second embodiment finishes the turn control and switches to the normal brake control when the driver's brake operation is detected during the turn control. Configure as follows.

  The detection of the driver's brake operation may be performed in the same manner as in the first embodiment. Further, the operation from the detection to the end of the turn control and the operation after shifting to the normal braking control may be performed by the vehicle control device of the second embodiment in the same manner as the first embodiment.

  Hereinafter, an example of the operation of the turning control (small turning control) in the case where there is a failure in the non-control system in the vehicle control device of the second embodiment will be described based on the flowchart of FIG.

  First, the electronic control unit 2 according to the second embodiment determines whether or not the turning control is being performed in the same manner as in the first embodiment (step ST5).

  When it is determined that the turning control is being performed, the vehicle control means of the electronic control device 2 according to the second embodiment determines whether there is a failure in the non-control system (step ST7). The failure of the non-control system mentioned here represents, for example, a malfunction of a master cut valve, a holding valve or the like in the non-control system of the brake fluid pressure adjusting means 40. For this reason, in this step ST7, for example, information on the failure is accumulated from the difference between the requested vehicle braking force and the actual vehicle braking force, and the judgment is made by referring to the past failure information. Just do it.

  If it is determined in step ST7 that there is a failure in the non-control system, the brake operation detecting means of the electronic control unit 2 determines whether or not the driver has operated the brake in the same manner as in the first embodiment (step ST7). ST10).

  Here, if it is determined that the brake operation has been performed, the vehicle control means sets the end time of the turn control according to the brake operation state value in the same manner as in the first embodiment (step ST15). The turning control is terminated in accordance with the end timing of the turning control (step ST20). After that, the brake fluid pressure control means is caused to execute normal braking control (step ST25).

For example, when only the right rear wheel _WRR is set as a turning control target wheel at the time of turning control as in the first embodiment, the vehicle control means sets the master cut valve 43 in the same manner as in the first embodiment in step ST20. The turn control is terminated by controlling with the indicated pressure. Thereby, the differential pressure between the upstream side and the downstream side of the master cut valve 43 gradually disappears toward the end timing of the turning control, and ends at the end time set for the turning control. During termination control period of the turn control, the braking force generating means 30 _RR swing control target wheels serving right rear wheel W _RR are applied the same brake fluid pressure in the case of the first embodiment.

Further, after finishing the turning control, the brake fluid pressure control means opens the master cut valves 42, 43 and the holding valves 50, 51, 52, 53 in step ST25, as in the first embodiment. At the same time, the pressure reducing valves 58, 59, 60, 61 are controlled to be closed. As a result, in the second brake hydraulic circuit system that was the control system, the master cut valve 43 and the holding valve 53 of the left front wheel _{WFL as} the turning outer wheel are switched to the open state, and the holding valve of the right rear wheel _WRR is changed. 52 and the pressure reducing valve 60 and the pressure reducing valve 61 of the left front wheel _WFL maintain the state during the turning control. This reason, the braking force generating means 30 _RR of the right rear wheel W _RR, (may be a brake hydraulic pressure pressurized by the pressurizing pump 70) the master cylinder pressure as in the case of Example 1 is continuously applied. On the other hand, for the braking force generating means 30 _{FL of the} left front wheel W _FL that is the non-turning control target wheel of the control system, the master cylinder pressure (brake fluid pressurized by the pressure pump 70 is applied) as in the first embodiment. The brake fluid pressure is increased until it reaches the pressure. Thus, since the vehicle control means generates a braking force on the non-turning control target wheel of the control system that has been controlled in the holding mode, even if the vehicle braking force is insufficient due to the failure of the non-control system, The vehicle braking force can be increased by the braking force of the non-turning control target wheel, and the actual vehicle braking force can be brought close to the required vehicle braking force or increased to the required vehicle braking force.

  Here, the electronic control unit 2 according to the second embodiment is not limited to the case where it is determined that the turning control is not being performed in Step ST5 or the case where it is determined that the driver is not performing the brake operation in Step ST10. Even when it is determined in step ST7 that there is no failure in the non-control system, the present calculation process is temporarily ended and the process returns to step ST5.

  As described above, the vehicle control apparatus according to the second embodiment performs turn control to prioritize the driver's intention when the driver's brake operation is detected during turn control when there is a failure in the non-control system. And switch to normal braking control. In other words, the vehicle control device switches to the pressure-increasing mode to generate the braking force for the wheels that are controlled in the holding mode during the turning control. Therefore, even if the vehicle braking force is insufficient due to the failure of the non-control system, this vehicle control device can apply the vehicle braking force requested by the driver to the vehicle or a vehicle braking force close to this. . Also in the vehicle control device of the second embodiment, the end time of the turn control according to the brake operation state value is set, so that the required vehicle braking force or the vehicle braking force close to this at the time intended by the driver. Will work. In addition, this vehicle control device smoothly shifts the brake fluid pressure of the turning control target wheel from the magnitude at the time of turning control to the master cylinder pressure (or the brake fluid pressure pressurized by the pressure pump 69 (70)). Because of this setting, a sudden change in vehicle braking force can be prevented. As described above, the vehicle control apparatus according to the second embodiment is configured so that the driver's requested vehicle braking force or the driver's requested braking force or the like can be obtained if the driver performs a braking operation during the turn control even if the non-control system has a failure. It is possible to satisfy the driver's braking request by applying a vehicle braking force close to 2 to the vehicle with an appropriate magnitude and timing. That is, this vehicle control device can suppress an increase in the difference between the actual vehicle deceleration and the driver's requested vehicle deceleration, and can eliminate the driver's uncomfortable feeling.

  As described above, the vehicle control device according to the present invention is useful for a technique that satisfies a driver's braking request when a brake is operated during turning control.

It is a figure which shows the structure of the vehicle control apparatus which concerns on this invention. It is a figure which shows the state of the brake hydraulic pressure adjustment means at the time of turning control. It is a time chart explaining the end time of turning control according to a master cylinder pressure, and brake fluid pressure of a wheel which is a control system at the time of turning control. FIG. 4 is a time chart corresponding to FIG. 3, illustrating the brake fluid pressure of the wheels that are in the non-control system during turning control. 3 is a flowchart illustrating an operation during turning control in the vehicle control device of the first embodiment. 6 is a flowchart showing an operation during turning control in the vehicle control device of Embodiment 2;

Explanation of symbols

1 Braking device 2 Electronic control unit (ECU)
DESCRIPTION OF SYMBOLS 10 Brake pedal 11 Brake pedal operation amount detection means 20 Brake fluid pressure generation means 30 _FR , 30 _FL , 30 _RR , 30 _RL Braking force generation means 40 Brake fluid pressure adjustment means 41 Master cylinder pressure sensor 42, 43 Master cut valve 50, 51, 52 and 53 holding valve 58, 59, 60, 61 pressure reducing valve 68 motor 69 booster pump 81 steering angle detecting means 82 vehicle speed detecting means 83 accelerator opening detection means 84 stop lamp switch _{W FR,} W FL, W _RR , W _RL wheel

Claims (2)

Brake fluid pressure regulating unit for each wheel capable of regulating the brake fluid pressure supplied to the braking force generating means, pressurizing the brake fluid and adjusting the brake fluid pressure after pressurizing the brake fluid pressure of the pair of front wheels and rear wheels Brake fluid pressure adjusting means provided with a pair of pressurizing parts to be supplied to the pressure parts and one electric motor for operating each of the pressure parts, and turning while controlling the brake fluid pressure adjusting means during turning of the vehicle In a vehicle control device having vehicle control means for performing turning control for reducing or maintaining the rotation radius by applying a braking force to at least one of the inner wheels,
The vehicle control device according to claim 1, wherein the vehicle control means is configured to end the turning control when a driver's brake operation is detected.   2. The vehicle control device according to claim 1, wherein the vehicle control means is configured to delay the end timing of the turning control as the brake operation amount of the driver is smaller.

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