CN100528652C - Controlling device for vehicle braking force - Google Patents

Abstract

In the present invention, when the open-type decompression solenoid valve is not fully closed, brake cylinder pressure control suitable for the situation occurs. Calculate the target brake cylinder pressure (Pti) (S40～70) of each wheel based on the driver’s brake operation amount, and control the linear valves 50FL～50RR and 60FL～60RR so that the brake cylinder pressure (Pi) becomes the target brake pressure. If the pump pressure (Pti) (S90, S120) and the linear valve (60RL) or (60RR) of the normally open decompression solenoid valve are not completely closed, the correction coefficient (Kai) is set as For values smaller than 1 (S210, 220, 230), the target brake cylinder pressures (Ptj) of the left and right rear wheels are reduced and corrected (S80).

Description

vehicle braking force control

technical field

The present invention relates to a braking force control device for a vehicle, and more specifically, to a so-called electronically controlled braking force control device.

Background technique

As a kind of braking force control device for vehicles such as automobiles, there is known conventionally, for example, the braking force control device described in the following Patent Document 1 filed by the applicant of the present application. The solenoid valve for boosting the pump pressure and the solenoid valve for reducing the pressure of the brake cylinder calculate the target brake cylinder pressure based on the driver's brake operation amount, and control the solenoid valve for boosting and pressure reducing Use the solenoid valve to make the brake cylinder pressure reach the target brake cylinder pressure.

Patent Document 1: Japanese Unexamined Patent Publication No. 11-235975

In the braking force control device as described above, generally, the solenoid valves for boosting and pressure reducing are normally closed solenoid valves, but normally closed solenoid valves are more expensive than normally open solenoid valves, so In order to reduce the cost of the braking force control device, it is conceivable to set the solenoid valves for depressurizing at least some of the wheels, for example, the left and right rear wheels, as normally open solenoid valves.

When the solenoid valve for decompression is a normally open solenoid valve, to increase or maintain the brake cylinder pressure, it is necessary to close the solenoid valve for decompression by supplying a control current to the normally open solenoid valve for decompression. Therefore, if the normally open decompression solenoid valve is not fully closed for some reason, the working fluid may leak from the brake cylinder side through the incompletely closed decompression solenoid valve. , so even if the specified boost control current is supplied to the solenoid valve for boosting, the brake cylinder pressure cannot be increased at the original boost ratio, and the maximum value of the brake cylinder pressure is also limited, resulting in excessive Disadvantages of controlling current supply to the solenoid valve for boosting.

Therefore, when the solenoid valve for decompression is constituted by a normally open solenoid valve, it is preferable to provide a preliminary device for dealing with the case where the normally open decompression solenoid valve is not fully closed.

Contents of the invention

The braking force control device of the present invention includes a solenoid valve for boosting and a solenoid valve for pressure reduction, calculates the target brake cylinder pressure based on the driver's brake operation amount, and controls the solenoid valve for boosting and the solenoid valve for pressure reduction. , so that the brake cylinder pressure reaches the target brake cylinder pressure, the purpose of which is to provide a solenoid valve for normally open pressure relief as described above when the solenoid valve for pressure relief is composed of a normally open solenoid valve. The preparation equipment for the case where the valve is not fully closed, the main subject of the present invention is: when the situation occurs that the normally open decompression solenoid valve is not completely closed, by using the normally open decompression solenoid valve The incompletely closed state of the solenoid valve changes the control of the booster solenoid valve, and when the normally open decompression solenoid valve is not completely closed, the brake cylinder pressure suitable for the situation occurs. control.

According to the above-mentioned main subject, if the present invention is adopted, the braking force control device of the vehicle includes a normally closed solenoid valve that is actuated according to the supplied control current to increase the pressure of the brake cylinder, and a normally closed solenoid valve that is actuated according to the supplied control current to reduce the pressure of the brake cylinder. The electromagnetic valve for the pump pressure controls the brake cylinder pressure to the target brake cylinder pressure by controlling the aforementioned normally closed electromagnetic valve and the aforementioned normally open electromagnetic valve. When the valve is in a fully closed state, the upper limit value of the target brake cylinder pressure is set according to the control current supplied to the aforementioned normally open solenoid valve, and the target brake cylinder pressure is limited below the aforementioned upper limit value, and the aforementioned normally open solenoid valve is controlled. A closed solenoid valve and the above-mentioned normally open solenoid valve (constitution of plan 1), or a braking force control device for a vehicle, which is provided with a normally closed solenoid valve that is actuated by the supplied control current to increase the pressure of the brake cylinder And the normally open solenoid valve that operates to reduce the brake cylinder pressure according to the supplied control current, and controls the brake cylinder pressure to the target brake cylinder by controlling the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve. The brake cylinder pressure is characterized in that when the above-mentioned normally open solenoid valve is to be fully closed, the upper part of the boosting ratio of the brake cylinder pressure is set according to the control current supplied to the above-mentioned normally open solenoid valve. The limit value limits the boosting ratio of brake cylinder pressure to below the aforementioned upper limit value, and controls the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve (constitution of plan 3).

In addition, if the present invention is adopted, in order to effectively achieve the above-mentioned main subject, as in the configuration of the above-mentioned scheme 1, the aforementioned braking force control device calculates the target brake cylinder pressure based on the driver's brake operation amount, and calculates the brake cylinder pressure for the brake cylinder. Target control currents of the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve which become target brake cylinder pressures so as to control the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve based on the target control current, When the normally open solenoid valve is to be fully closed, the corrected target brake cylinder pressure is reduced based on the control current supplied to the normally open solenoid valve, and based on the corrected target brake cylinder pressure, Calculate the target control current of the above-mentioned normally closed solenoid valve, and limit the target brake cylinder pressure below the above-mentioned upper limit (constitution of plan 2).

In addition, if the present invention is adopted, in order to effectively achieve the above-mentioned main subject, as in the configuration of the above-mentioned scheme 3, the aforementioned braking force control device calculates the target brake cylinder pressure based on the driver's brake operation amount, and the calculation is used to make the brake cylinder pressure Target control currents of the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve which become target brake cylinder pressures so as to control the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve based on the target control current, When the normally open solenoid valve is to be fully closed, the target control current of the normally closed solenoid valve is reduced and corrected based on the control current supplied to the normally open solenoid valve, and the brake cylinder pressure is reduced. The supercharging ratio is limited below the aforementioned upper limit (constitution of Scheme 4).

In addition, if the present invention is adopted, in order to effectively achieve the above-mentioned main subject, as in the configurations of the above-mentioned schemes 1 to 4, when the aforementioned braking force control device is in the control mode of increasing or maintaining the pressure of the brake cylinder, it is determined that the aforementioned normally-open type When the solenoid valve is in a fully closed state (the composition of scheme 5).

In addition, according to the present invention, in order to effectively achieve the above-mentioned main subject, as in the above-mentioned configurations 1 to 4, when the braking force control device supplies a control current exceeding the rated maximum current to the normally-open solenoid valve, it is judged that When the aforementioned normally open solenoid valve is to be in a fully closed state (constitution of scheme 6).

If the composition of the above scheme 1 is adopted, when the normally open solenoid valve is fully closed, the upper limit value of the target brake cylinder pressure is set according to the control current supplied to the normally open solenoid valve, and the target brake The slave cylinder pressure is limited below the upper limit value to control the normally closed solenoid valve and the normally open solenoid valve, so even if for some reason the normally open pressure reducing solenoid valve is not fully closed In this case, the disadvantage of not being able to control the brake cylinder pressure to the target brake cylinder pressure can also be reduced, and the disadvantage of supplying an excessive control current to the solenoid valve for boosting can be reduced.

In addition, if the configuration of the above-mentioned claim 2 is adopted, the brake force control device calculates the target brake cylinder pressure based on the driver's brake operation amount, and calculates the above-mentioned normally closed type brake cylinder pressure for making the brake cylinder pressure equal to the target brake cylinder pressure. The target control current of the electromagnetic valve of the aforementioned normally open type and the target control current of the aforementioned normally open electromagnetic valve, so that based on the target control current, the aforementioned normally closed type of electromagnetic valve and the aforementioned normally open type of electromagnetic valve are controlled, in order to make the aforementioned normally open electromagnetic valve become In the fully closed state, the corrected target brake cylinder pressure is reduced based on the control current supplied to the normally open solenoid valve, and the target control of the normally closed solenoid valve is calculated based on the corrected target brake cylinder pressure. current, to limit the target brake cylinder pressure below the aforementioned upper limit, so when the normally open solenoid valve is to be fully closed, the target brake cylinder pressure can be reliably limited to the value supplied to the normally open solenoid valve. The valve control current upper limit value or less.

In addition, if the configuration of the above-mentioned claim 3 is adopted, when the aforementioned normally-open solenoid valve is to be fully closed, the boost ratio of the brake cylinder pressure is set according to the control current supplied to the aforementioned normally-open solenoid valve. The upper limit value of the brake cylinder pressure is limited to below the upper limit value, and the aforementioned normally closed solenoid valve and the aforementioned normally open solenoid valve are controlled, so even if the normally open solenoid valve occurs for some reason When the decompression solenoid valve is not completely closed, the brake cylinder pressure can be increased according to the boost ratio limited below the upper limit, thereby reducing the disadvantages of being unable to control the target brake cylinder pressure. Furthermore, it is possible to reduce the disadvantage of supplying an excessive control current to the solenoid valve for boosting.

In addition, if the configuration of the above-mentioned claim 4 is adopted, the brake force control device calculates the target brake cylinder pressure based on the driver's brake operation amount, and calculates the aforementioned normally closed brake cylinder pressure for making the brake cylinder pressure equal to the target brake cylinder pressure. The target control current of the electromagnetic valve and the aforementioned normally open electromagnetic valve, so that based on the target control current, the aforementioned normally closed electromagnetic valve and the aforementioned normally open electromagnetic valve are controlled, in order to make the aforementioned normally open electromagnetic valve fully In the closed state, according to the control current supplied to the normally open solenoid valve, the target control current of the normally closed solenoid valve is reduced and corrected, and the boosting ratio of the brake cylinder pressure is limited below the above upper limit value, Therefore, when the normally open solenoid valve is to be fully closed, the boost ratio of the brake cylinder pressure can be reliably limited below the upper limit value based on the control current supplied to the normally open solenoid valve.

In addition, if the composition of the above-mentioned scheme 5 is adopted, when it is in the control mode of increasing or maintaining the pressure of the brake cylinder, when it is determined that the aforementioned normally open solenoid valve is to be in a fully closed state, and if the composition of the above-mentioned scheme 6 is adopted, in the When supplying a control current exceeding the rated maximum current to the normally open solenoid valve, it is judged that the aforementioned normally open solenoid valve is to be in the fully closed state, so it can be reliably judged that the normally open solenoid valve is to be fully closed. When closed.

If a preferred mode of the present invention is adopted, as in the above schemes 1 to 6, the braking force control device has a normally closed solenoid valve for increasing the pressure of the brake cylinder on the left and right front wheels and a normally open solenoid valve for reducing the pressure of the brake cylinder. The solenoid valve of the type has a normally closed solenoid valve for increasing the brake cylinder pressure to the left and right rear wheels and a normally open solenoid valve for reducing the brake cylinder pressure (preferred mode 1).

If another preferred mode of the present invention is adopted, as in the above-mentioned schemes 1 to 6, the normally closed solenoid valve and the normally open solenoid valve are composed of linear electromagnetic coils (preferred mode 2).

If another preferred mode of the present invention is adopted, as in the configuration of the above-mentioned scheme 1, the braking force control device calculates the target deceleration of the vehicle based on the driver's brake operation amount, and calculates the target deceleration of each wheel based on the target deceleration of the vehicle. For the brake cylinder pressure, when calculating the target brake cylinder pressure based on the target deceleration of the vehicle, when the normally open solenoid valve is fully closed, the correction is reduced according to the control current supplied to the normally open solenoid valve Target brake cylinder pressure (optimal mode 3).

If another preferred mode of the present invention is adopted, as in the above-mentioned scheme 3, the braking force control device calculates the target brake cylinder pressure of each wheel based on the driver's brake operation amount, and calculates the target brake cylinder pressure based on the target brake cylinder pressure and the actual brake pressure. Calculate the deviation of the slave cylinder pressure, calculate the target control current of the normally closed solenoid valve and the aforementioned normally open solenoid valve, and when the normally open solenoid valve is to be fully closed, according to the current supplied to the normally open solenoid valve reduce the target control current of the normally open solenoid valve (optimal mode 4).

If another preferred mode of the present invention is adopted, as in the above-mentioned scheme 1 or 2, when the control mode is the boost mode, the target brake cylinder pressure can be limited below the upper limit (preferred mode 5).

If another preferred mode of the present invention is adopted, such as the configuration of the above schemes 3 and 4, when the control mode is the supercharging mode, the supercharging ratio of the brake cylinder pressure can be limited below the upper limit (preferable mode 6).

Description of drawings

1 is a schematic configuration diagram showing a hydraulic circuit and a block diagram showing a control system of Embodiment 1 of a braking force control device for a vehicle according to the present invention. (Example 1)

FIG. 2 is a flowchart showing a braking force control routine of the first embodiment. (Example 1)

FIG. 3 is a graph showing the relationship between the average value Pma of the master cylinder pressure and the target deceleration Gpt. (Examples 1 and 2)

FIG. 4 is a graph showing the relationship between the depression stroke St of the brake pedal and the target deceleration Gst. (Example 1 and 2)

FIG. 5 is a graph showing the relationship between the previous final target deceleration Gtf and the weight α to the target deceleration Gpt. (Examples 1 and 2)

6 is a flowchart showing a calculation routine of a correction coefficient Kaj for the target brake cylinder pressure Ptj of the left and right rear wheels in the first embodiment. (Example 1)

FIG. 7 is a graph showing the relationship between the target control current Idj and the correction coefficient Kaj of the linear valves 60RL, 60RR. (Example 1)

FIG. 8 is a graph showing the relationship between brake cylinder pressure ΔPi and target control currents Ihi, Idj. (Examples 1 and 2)

FIG. 9 is a flowchart showing a braking force control routine of the second embodiment. (Example 2)

10 is a flowchart showing a calculation routine of a correction coefficient Kbj for the target control current Ihj of the left and right rear wheels in the second embodiment. (Example 2)

FIG. 11 is a graph showing the relationship between the target control current Idj and the correction coefficient Kbj of the linear valves 60RL, 60RR. (Example 2)

Detailed ways

Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Example 1)

1 is a schematic configuration diagram of a hydraulic circuit showing Embodiment 1 of a braking force control device for a vehicle according to the present invention and a block diagram showing a control system. And in FIG. 1 , the solenoids of the respective valves are omitted for simplicity.

In FIG. 1 , 10 denotes an electrically controlled hydraulic brake device, and the brake device 10 has a brake master cylinder 14 that pressurizes and feeds brake fluid in response to an operation of the driver depressing a brake pedal 12 . A dry stroke simulator 16 is provided between the brake pedal 12 and the master brake cylinder 14 .

The brake master cylinder 14 has a first brake master cylinder chamber 14A and a second brake master cylinder chamber 14B, and the brake oil pressure supply conduit 18 for the left front wheel and the brake oil pressure supply pipe 18 for the right front wheel are respectively connected to these master cylinder chambers. One end of the control catheter 20 . The other ends of the brake oil pressure control conduits 18 and 20 are respectively connected with brake cylinders 22FL and 22FR for controlling the braking force of the left front wheel and the right front wheel.

In the middle of the brake oil pressure supply conduits 18 and 20, there are respectively normally open electromagnetic on-off valves (general switching valves) 24L and 24R, and the electromagnetic on-off valves 24L and 24R respectively play a role in controlling the communication between the brake cylinders 22FL and 24FL. The function of the blocking valve, the brake cylinder corresponds to the first brake master cylinder chamber 14A and the second brake master cylinder chamber 14B. Furthermore, a wet stroke simulator 28 is connected to the brake fluid pressure supply conduit 18 between the master cylinder 14 and the electromagnetic on-off valve 24FL via a normally-closed electromagnetic on-off valve (normally-closed valve) 26 .

An oil tank 30 is connected to the brake master cylinder 14 , and one end of an oil pressure supply conduit 32 is connected to the oil tank 30 . An oil pump 36 driven by a motor 34 is provided in the middle of the hydraulic supply conduit 32 , and an accumulator 38 for accumulating high pressure hydraulic pressure is connected to the hydraulic supply conduit 32 on the discharge side of the oil pump 36 . One end of an oil pressure discharge conduit 40 is connected to the oil pressure supply conduit 32 between the oil tank 30 and the oil pump 36 . The oil tank 30 , the oil pump 36 , the accumulator 38 and the like function as high-pressure pressure sources for increasing the pressure in the brake cylinders 22FL, 22FR, and 22RR as will be described later.

Although not shown in FIG. 1 , there is a conduit connecting the oil pressure supply conduit 32 on the suction side of the oil pump 36 and the oil pressure supply conduit 32 on the discharge side, and a safety valve is provided in the middle of the conduit to act as an accumulator. When the pressure in the valve 38 exceeds the reference value, it opens to return the oil from the hydraulic supply conduit 32 on the discharge side to the hydraulic supply conduit 32 on the suction side.

The oil pressure supply conduit 32 on the discharge side of the oil pump 36 is connected to the brake oil pressure supply conduit 18 between the electromagnetic on-off valve 24L and the brake cylinder 22FL through the oil pressure control conduit 42, and is connected to the electromagnetic on-off valve through the oil pressure control conduit 44. 24R is connected to the brake oil pressure supply conduit 20 between the brake cylinder 22FR, connected to the brake cylinder 22RL for the left rear wheel through the oil pressure control conduit 46, and connected to the brake cylinder for the right rear wheel through the oil pressure control conduit 48 22 RR connection.

Normally closed electromagnetic linear valves 50FL, 50FR, 50RL, and 50RR are provided in the middle of the oil pressure control conduits 42, 44, 46, and 48, respectively. The oil pressure control conduits 42, 44, 46, 48 on the side of the brake cylinders 22FL, 22FR, 22RL, 22RR relative to the linear valves 50FL, 50FR, 50RL, 50RR are respectively discharged through the oil pressure control conduits 52, 54, 56, 58. Conduit 40 is connected, and normally closed electromagnetic linear valves 60FL, 60FR are respectively provided in the middle of oil pressure control conduits 52, 54, and the middle of oil pressure control conduits 56, 58 are respectively provided with lower than normally closed valves. Electromagnetic linear valve normally open electromagnetic linear valve 60RL, 60RR.

Linear valves 50FL, 50FR, 50RL, and 50RR act as booster valves (holding valves) for brake cylinders 22FL, 22FR, 22RL, and 22RR respectively, and linear valves 60FL, 60FR, 60RL, and 60RR act as booster valves for brake cylinders 22FL , 22FR, 22RL, and 22RR are pressure-reducing valves, so these linear valves work together to form a pressure-increasing control valve for controlling the supply/discharge of high-pressure oil from the accumulator 38 to each brake cylinder.

In addition, when each electromagnetic on-off valve, each linear valve, and the motor 34 do not supply a driving current, the electromagnetic on-off valves 24L and 24R maintain the valve open state, and the electromagnetic on-off valve 26, the linear valves 50FL to 50RR, and the linear valve 60FL and 60FR maintain the closed state, and the linear valves 60RL and 60RR maintain the open state (non-control mode). Moreover, when one of the linear valves 50FL to 50RR and linear valves 60FL to 60RR is broken, so that the pressure in the corresponding brake cylinder cannot be controlled to normal, each electromagnetic on-off valve, etc. can also be set to the non-control mode. , the pressure in the brake cylinders of the left and right front wheels can be directly controlled by the brake master cylinder 14.

As shown in FIG. 1, the brake oil pressure control conduit 18 between the first brake master cylinder chamber 14A and the electromagnetic on-off valve 24L is provided with a first brake oil pressure control conduit 18 which detects the pressure in the control conduit as the first brake master cylinder pressure Pm1. Pressure sensor 66. Likewise, the brake fluid pressure control conduit 20 between the second master cylinder chamber 14B and the electromagnetic on-off valve 24B is provided with a second pressure sensor 68 for detecting the pressure in the control conduit as the second master cylinder pressure Pm2. The brake pedal 12 is provided with a stroke sensor 70 that detects the stroke St of the driver stepping on the brake pedal, and the oil pressure supply conduit 32 on the discharge side of the oil pump 34 is provided with a pressure sensor that detects the pressure in the conduit as the accumulator pressure Pa. Pressure sensor 72.

The brake oil pressure supply conduits 18 and 20 between the electromagnetic on-off valves 24L and 24R and the brake cylinders 22FL and 22FR are respectively provided with the pressure in the corresponding conduits as the internal pressure Pf1 and Pfr of the brake cylinders 22FL and 22FR. The pressure transducers 74FL and 74FR. Moreover, the oil pressure supply conduits 46 and 48 between the electromagnetic on-off valves 50RL and 50RR and the brake cylinders 22RL and 22RR are respectively provided with the pressure in the corresponding conduits as the internal pressures Pr1 and Prr of the brake cylinders 22RL and 22RR. Test pressure sensors 74RL and 74RR.

Electromagnetic on-off valves 24L and 24R, electromagnetic on-off valve 26 , motor 34 , linear valves 50FL to 50RR, and linear valves 60FL to 60RR are controlled by an electronic control device 78 . The electronic control unit 78 is composed of a microcomputer 80 and a drive circuit 82 . Also, the microcomputer 80 is not shown in detail in FIG. 1 , but may have a general configuration including, for example, a CPU, ROM, RAM, and I/O port devices, and these are connected by a bidirectional common bus.

Input the following signals to the microcomputer 80: the signals representing the first brake master cylinder pressure Pm1 and the second brake master cylinder pressure Pm2 through the pressure sensors 66 and 68, the signals representing the stroke St of the brake pedal 12 through the stroke sensor 70, and the pressure Sensor 72 indicates a signal of accumulator pressure Pa, and a signal Pi (i=f1, fr, r1, rr) of pressure in brake cylinders 22FL to 22RR is indicated by pressure sensors 74FL to 74RR, respectively.

The microcomputer 80 has stored the braking force control program of the flow chart shown in Figure 2 as described later, if the brake pedal 12 is stepped on, the electromagnetic on-off valve 26 is opened, and the electromagnetic on-off valve 24L and 24R are closed simultaneously. In this state, Based on the master cylinder pressures Pm1 and Pm2 detected by the pressure sensors 66 and 68 and the pedal stroke St detected by the stroke sensor 70, the target deceleration Gt of the vehicle is calculated, and the target braking points of each wheel are calculated based on the target deceleration Gt of the vehicle. The pump pressure Pti (i=f1, fr, r1, rr) is calculated to be greater than the brake master cylinder pressure Pm1, Pm2, control each linear valve 50FL ~ 50RR and 60FL ~ 60RR, so that the brake pressure Pi of each wheel is greater than the target brake pressure Pump pressure Pti.

As can be seen from the above description, the microcomputer 80 constitutes a control device: based on the driver's brake operation amount, calculates the target brake cylinder pressure of each wheel, and communicates with the electromagnetic on-off valves 24L and 24R, the electromagnetic on-off valve 26, the motor 34, the linear Sensors such as valves 50FL-50RR, linear valves 60FL-60RR, electronic control device 78, and pressure sensor 66 work together to control the electromagnetic on-off valves 24L and 24R by using the pressure of the high-pressure source. The brake cylinder pressure of each wheel is made to be the corresponding target brake cylinder pressure.

For the illustrated embodiment, when the control mode of the microcomputer 80 to the left and right rear wheels is the pressurization mode or the maintenance mode, in other words, when the linear valves 60RL and 60RR are to be fully closed, when the linear valves 60RL and 60RR are When the target control current Idj (j=r1, rr) is above the instruction value for releasing the linear valves 60RL, 60RR, that is, above the rated maximum current of the linear valve, the target brake cylinder pressure Ptj (j= r1, rr), thereby preventing the brake cylinder pressure Pj of the wheel from being unable to be controlled to the target brake cylinder pressure Ptj and excessive control current being supplied to the linear valves 50RL, 50RR of the wheel.

Next, the braking force control in the embodiment will be described with reference to the flowchart shown in FIG. 2 . And, the control based on the flowchart shown in FIG. 2 starts when the microcomputer 80 is activated, and is repeatedly executed every predetermined time. And steps 80 and 90 are only carried out for the left and right rear wheels.

First, in step 10, it is judged whether the driver has a braking request, if the judgment is no, go to step 20, and if the judgment is affirmative, go to step 30. And, for judging whether the driver has a braking request, for example, whether the average value Pma of the brake master cylinder pressures Pm1 and Pm2 detected by the pressure sensors 66, 68 is above the initial reference value Pms (normal number) or whether it is determined by the stroke sensor 70 Detect whether or not the pedaling stroke St is equal to or greater than the initial reference value Sts (normal number).

In step 20, open the electromagnetic on-off valve 26 or maintain the open state, and close the electromagnetic on-off valve 24L and 24R at the same time or maintain the closed state, thereby connecting and communicating with the brake master cylinder 14 and the wet stroke simulator 28, and blocking the brakes simultaneously. Communication between the master cylinder 14 and the brake cylinders 22FL, 22FR, 22RL, and 22RR of the wheels. In step 30, the electromagnetic on-off valve 26 is opened, and the electromagnetic on-off valves 24L and 24R are released simultaneously, thereby blocking the communication between the brake master cylinder 14 and the wet stroke simulator 28, and simultaneously connecting the brake master cylinder 14 and each wheel. Brake cylinders 22FL, 22FR, 22RL, 22RR.

In step 40, a signal indicating the master cylinder pressure Pm1 detected by the pressure sensor 66 is read, and based on the average value Pma of the master cylinder pressures Pm1 and Pm2, the calculation is based on a graph corresponding to the graph shown in FIG. Target deceleration Gpt of brake master cylinder pressure.

In step 50 , based on the pedaling stroke St detected by the stroke sensor 70 , a target deceleration Gst based on the pedaling stroke is calculated from a map corresponding to the graph shown in FIG. 4 .

In step 60, based on the previous final target deceleration Gtf, the weight α (0≤α≤1) for the target deceleration Gpt is calculated according to the graph corresponding to the graph shown in FIG. 1. Calculate the final target deceleration Gt which is the weighted sum of the target deceleration Gpt and the target deceleration Gst. Also, in the illustrated embodiment, the weight α may be calculated based on the previous final target deceleration Gtf, but may be modified to be calculated based on the target deceleration Gpt or Gst.

Gt＝α·Gpt+(1-α)Gst ... (1)

In step 70, the coefficient of the target brake cylinder pressure of each wheel relative to the final target deceleration Gt (a positive coefficient considering the braking effect coefficient of each wheel) is set as Ki (i=f1, fr, r1, rr), according to The following Equation 2 calculates the target brake cylinder pressure Pti (i=f1, fr, r1, rr) of each wheel.

Pti=Ki Gt...(2)

In step 80, it is judged whether the control mode of the left and right rear wheels is a supercharging mode, and when it is judged as no, it directly enters step 100; In the program shown in 6, the calculated correction number Kaj (j=r1, rr) calculates the correction value Ptaj of the target brake cylinder pressure of the left and right rear wheels according to the following formula 3, and these correction values become the corrected target brake pressure. Pump pressure Ptj.

Ptai＝Kai·Ptj ……(3)

In step 100, based on the deviation ΔPi between the target brake cylinder pressure Pti and the brake cylinder pressure Pi of each wheel, the target current Ihi and linear The target current Idi of the valves 60FL-60RR controls the linear valves 50FL-50RR and the linear valves 60FL-60RR based on the target currents Ihi and Idi in step 130 to control the brake pressure Pi of each wheel to the target brake cylinder pressure Pti.

6 is a flowchart showing a calculation routine of a correction coefficient Kaj for the target brake cylinder pressure Ptj of the left and right rear wheels in the first embodiment. In addition, the calculation of the correction coefficient Kaj according to the program shown in FIG. 3 may be performed alternately for the left and right rear wheels at predetermined intervals, for example, in the order of the left rear wheel and the right rear wheel.

In addition, in step 210, it is judged whether the braking force control mode of the wheel is boost mode or hold mode, if the judgment is negative, go to step 240, if the judgment is affirmative, go to step 220.

In step 220, it is judged that the target control current Idj (j=r1, rr), which is the command value of the pressure reducing valve (linear valve 60RL, 60RR) of the wheel, is equal to or greater than the current value for closing the pressure reducing valve. If the decompression valve of the wheel is normal and the control status of whether it is in the closed state is judged to be positive, in step 230, based on the target control current Idj, the correction coefficient Kaj is calculated according to the graph corresponding to the graph shown in FIG. In step 240, the correction coefficient value Kaj remains the previous value.

Furthermore, if the illustrated embodiment 1 is used, in steps 40 to 70, the target brake cylinder pressure Pti of each wheel is calculated based on the driver's brake operation amount, and the correction coefficient Kai is set when the linear valves 60RL and 60RR are normal. If it is set to 1, the target brake cylinder pressure Ptj of the left and right rear wheels will not be reduced and corrected. Therefore, when the electromagnetic on-off valves 24L and 24R are closed, the brake-by-wire type is controlled to make the brake cylinder pressure Pi of each wheel The target brake pressure Pti is greater than the brake master cylinder pressure Pm1, Pm2.

On the contrary, if there is an abnormal situation in which the linear valve 60RL or 60RR is not fully closed, it is judged as affirmative in steps 210 and 220, and in step 230, the correction coefficient Kai is set to a value smaller than 1, and the left and right rear wheels Since the target cylinder pressure Ptj is reduced and corrected, it is possible to reliably prevent the situation that the brake cylinder pressure Pj of the wheel cannot be controlled to the target brake cylinder pressure Ptj and provide excessive control to the linear valves 50RL, 50RR of the wheel. current situation.

In particular, if the illustrated embodiment 1 is used, when the target control current Idj of the linear valves 60RL, 60RR is greater than or equal to the command value for closing the linear valves 60RL, 60RR, the correction coefficient Kai is set according to the target control current Idj so that the target The larger the control current Idj is, the smaller the coefficient Kai is. Therefore, the corrected target brake cylinder pressure Ptj for the left and right rear wheels can be appropriately reduced according to the condition that the linear valves 60RL and 60RR cannot be closed.

In addition, if the illustrated embodiment 1 is used, in step 80, when it is determined that the control mode for the left and right rear wheels is the supercharging mode, correction values Ptaj for the target brake cylinder pressures of the left and right rear wheels can be calculated, and these correction values Since this becomes the corrected target cylinder pressure Ptj, when the control mode is the hold mode or the boost mode, it is possible to reliably prevent the target cylinder pressure Ptj for the left and right rear wheels from being corrected to decrease unnecessarily.

(Example 2)

9 is a flow chart showing a braking force control routine of the second embodiment of the vehicle braking force control device of the present invention, and FIG. 10 is a flow chart showing a positive coefficient Kbj calculation routine of the second embodiment. And in Fig. 9 and Fig. 10, the steps equivalent to the steps shown in Fig. 2 and Fig. 3 are respectively marked with the same step numbers as those marked in Fig. 2 and Fig. 3 . In addition, the calculation of the correction coefficient Kbj performed by the program shown in FIG. 10 is also performed, for example, in the order of the left rear wheel and the right rear wheel at predetermined intervals for the left and right rear wheels. And steps 100 and 110 are only performed on the left and right rear wheels.

In this embodiment, steps 10 to 70, 100, and 130 are performed in the same manner as in the above-mentioned embodiment 1, but in step 110 performed after step 100, it is determined in the same manner as in step 80 of embodiment 1 that the left and right rear wheels If the control mode is the supercharging mode, if the judgment is negative, directly enter step 130, and if the judgment is positive, in step 120, the target control of the linear valves 50RL, 50RR of the rear wheel is calculated by the following formula 4 The correction value Ihbj of the current is corrected by reducing the target control current Ihj by setting the correction value Ihbj of the target control current as the corrected target control current Ihj.

Ihbj＝Kbi·Ihj ……(4)

In addition, steps 210 and 220 shown in FIG. 10 are carried out in the same manner as in the case of the first embodiment described above. When the judgment in step 220 is positive, in step 250 based on the target control current Idj, the graph shown in FIG. 11 The correction coefficient Kbj is calculated according to the corresponding map, and when the judgment in step 210 or 220 is negative, the correction coefficient Kbj is maintained at the previous value in step 260 .

Therefore, if the illustrated embodiment 2 is used, if an abnormal situation occurs in which the linear valve 60RL or 60RR is not fully closed, an affirmative judgment is made in steps 210 and 220, and the correction coefficient Kbi is set to be less than With a value of 1, the target control current Ihj of the linear valve for supercharging the left and right rear wheels is reduced and corrected, so that it is possible to reliably prevent the situation that the brake cylinder pressure Pj of the wheel cannot be boosted and controlled to the target brake cylinder pressure Ptj And there is a case where an excess control current is supplied to the linear valves 50RL, 50RR of the wheel.

In particular, if the illustrated embodiment 2 is used, when the target control current Idj of the linear valves 60RL and 60RR is greater than or equal to the command value for closing the linear valves 60RL and 60RR, the correction coefficient Kai is set according to the target control current Idj so that the target The larger the control current Idj is, the smaller the coefficient Kai is. Therefore, the corrected target brake cylinder pressure Ptj for the left and right rear wheels can be appropriately reduced according to the condition that the linear valves 60RL and 60RR cannot be closed.

In addition, if the illustrated embodiment 2 is used, in step 100, when it is determined that the control mode for the left and right rear wheels is the supercharging mode, the correction target control current Idj can be reduced, so when the control mode is the holding mode or the supercharging mode Therefore, it is possible to reliably prevent the target control current Ihj of the linear valve for supercharging the left and right rear wheels from being unnecessarily reduced and corrected.

In addition, if the illustrated embodiment 1 or 2 is used, the linear valves 60RL and 60RR of the left and right rear wheels are normally open solenoid valves, so when an abnormal situation occurs in which the linear valves 60RL or 60RR are not completely closed, the braking force of the rear wheels will be activated. When the power is limited, the driver's brake operation amount increases, so even if the braking force of the front wheels becomes larger, the side force of the rear wheels caused by the braking force of the rear wheels will not decrease, so it is different from the left and right front wheels. Compared with the case where the linear valves 60FL and 60FR are normally open solenoid valves, in other words, compared with the case where an abnormality occurs and the braking force of the rear wheels increases, the force caused by the reduction of the lateral force of the rear wheels can be surely reduced. Disadvantages such as deterioration of vehicle behavior.

As mentioned above, the present invention has been described in detail with reference to specific embodiments, but the present invention is not limited to the above-described embodiments, and those skilled in the art can implement other various embodiments within the scope of the present invention.

For example, in the first embodiment above, if the linear valve 60RL or 60RR is not completely closed, the target brake cylinder pressure Ptj itself is reduced and corrected for the left and right rear wheels. On the right side, the multiplication of the correction coefficient Kai is performed, and it is modified so that the target brake cylinder pressure Ptj of the left and right rear wheels is calculated as a reduced value.

In addition, in the above-mentioned embodiment 2, when the abnormal situation in which the linear valve 60RL or 60RR is not fully closed occurs, the target control current Ihj for the linear valve 50RL, 50RR is reduced and corrected, but the target brake current Ihj of the left and right rear wheels passes through The deviation ΔPi between the cylinder pressure and the brake cylinder pressure is reduced and corrected so that the target control current Ihj for the linear valves 50RL, 50RR is reduced and corrected.

In addition, in the above-mentioned embodiment, when an abnormality occurs in which the linear valve 60RL or 60RR is not fully closed, the target brake cylinder pressure Ptj corrected for the left and right rear wheels is individually reduced, or the corrected value is reduced. The target brake cylinder pressure and the deviation ΔPi of the brake cylinder pressure, but the linear valve 60RL or 60RR of a certain rear wheel is not in a completely closed state, so that the braking force difference between the left and right rear wheels will not work on the vehicle In the case of unnecessary torque, it may be modified to reduce the corrected target cylinder pressure Ptj for both the left and right rear wheels, or may be modified to reduce the deviation ΔPi between the corrected target brake cylinder pressure and the brake cylinder pressure.

In addition, if the above-mentioned embodiments are adopted, the target control current Ihi and Idi of each wheel are calculated from the diagram shown in Fig. 8, but it can also be modified so that the diagram can be variably set according to the target control current Ihi, and the target control current Idi of each wheel The brake cylinder Pti and the target control currents Ihi and Idj are calculated by functions, and these functions are variably set according to the target control current Idj.

In addition, in each of the above-mentioned embodiments, the target value dynamic pressure Pti of each wheel is based on the average value Pma of the master cylinder pressures Pm1, Pm2 and the depression amount of the brake pedal as a value indicating the driver's brake operation amount in normal times. St calculates the driver's required deceleration Gt, and the target brake cylinder Pti of each wheel is calculated based on the driver's required deceleration Gt, but as long as it is normal, the target control pressure Pti of each wheel is calculated based on at least the brake master cylinder pressure, and the braking force The control itself can be implemented under the guidance of any idea known in the technical field.

Furthermore, master cylinder pressure is sensed by two pressure sensors 66 and 68, but it can also be modified that master cylinder pressure is sensed by one pressure sensor.

Claims (6)

1. vehicle braked force control device, possess according to the control current start of supplying with increase wheel cylinder pressure closed type electromagnetic valve and reduce the electromagnetic valve of the open type of wheel cylinder pressure according to the control current start of supplying with, the electromagnetic valve by controlling described closed type and the electromagnetic valve of described open type, with the wheel cylinder pressure control is target wheel cylinder pressure, it is characterized in that

When the electromagnetic valve that will make described open type becomes full closing state, control current according to the electromagnetic valve that supplies to described open type, target setting wheel cylinder upper limit of pressure value, target wheel cylinder pressure confinement below described higher limit, is controlled the electromagnetic valve of described closed type and the electromagnetic valve of described open type.

2. vehicle braked force control device as claimed in claim 1, wherein,

The formation of described gradual braking device, brake operating amount based on the driver, computing target wheel cylinder pressure, the target control electric current of the electromagnetic valve of the described closed type that computing is used to make wheel cylinder pressure become target wheel cylinder pressure and the electromagnetic valve of described open type, so that based target control current, control the electromagnetic valve of described closed type and the electromagnetic valve of described open type, when the electromagnetic valve that will make described open type becomes full closing state, control current according to the electromagnetic valve that supplies to described open type, reduce revisal target wheel cylinder pressure, by based on the target wheel cylinder pressure after the revisal, the target control electric current of the electromagnetic valve of the described closed type of computing, with target wheel cylinder pressure confinement on described below the restriction.

3. vehicle braked force control device, possess according to the control current start of supplying with increase wheel cylinder pressure closed type electromagnetic valve and reduce the electromagnetic valve of the open type of wheel cylinder pressure according to the control current start of supplying with, the electromagnetic valve by controlling described closed type and the electromagnetic valve of described open type, with the wheel cylinder pressure control is target wheel cylinder pressure, it is characterized in that

When the electromagnetic valve that will make described open type becomes full closing state, control current according to the electromagnetic valve that supplies to described open type, set the supercharging ratiometric higher limit of wheel cylinder pressure, the supercharging ratio of wheel cylinder pressure is restricted to below the described higher limit, controls the electromagnetic valve of described closed type and the electromagnetic valve of described open type.

4. vehicle braked force control device as claimed in claim 3, wherein,

The formation of described gradual braking device, brake operating amount based on the driver, computing target wheel cylinder pressure, the target control electric current of the electromagnetic valve of the described closed type that computing is used to make wheel cylinder pressure become target wheel cylinder pressure and the electromagnetic valve of described open type, so that based target control current, control the electromagnetic valve of described closed type and the electromagnetic valve of described open type, when the electromagnetic valve that will make described open type becomes full closing state, supply to the control current of the electromagnetic valve of described open type by basis, reduce the target control electric current of the electromagnetic valve of the described closed type of revisal, the supercharging ratio of wheel cylinder pressure is limited in below the described higher limit.

5. as each described vehicle braked force control device in the claim 1 to 4, wherein,

Described gradual braking device increases or when keeping the master mode of wheel cylinder pressure being in, and is judged as the electromagnetic valve that will make described open type when being in full closing state.

6. as each described vehicle braked force control device in the claim 1 to 4, wherein,

When described gradual braking device is supplied with control current more than the specified maximum current in the electromagnetic valve of described open type, be judged as the electromagnetic valve that will make described open type when being in full closing state.

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