JPH05278596A - Slip controller of vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] The anti-skid brake control and brake traction control are stopped when the system of the engine traction control microcomputer is down. [Structure] First and second microcomputers 69 and 70 for dually performing anti-skid brake control and brake traction control, a third microcomputer 71 for performing engine traction control, and monitoring runaway of the microcomputers 69 and 70. A first monitor circuit 72, a second monitor circuit 73 that monitors the runaway of the microcomputer 71, and a first AND gate that outputs a logical product of the output signals of the microcomputers 69 and 70 and the output signals of both monitor circuits 72 and 73. 74 and a second AND gate 75 for outputting a logical product of the output signal of the microcomputer 71 and the output signals of both monitoring circuits 72 and 73.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle slip control device, and more particularly to a vehicle provided with anti-skid brake control means, brake traction control means, and engine traction control means, in which measures are taken when the system goes down. Regarding

[0002]

2. Description of the Related Art Various slip control devices (traction control devices) have been proposed to prevent excessive slip of driving wheels on a road surface during acceleration of a vehicle and to satisfy acceleration and vehicle stability. It has been put to practical use. The traction control is performed so as to reduce the torque applied to the drive wheels, and thus brake traction control for applying a braking force to the drive wheels and engine traction control for reducing the output torque of the engine are performed. In the traction control, it is general to perform feedback control so that the actual slip value of the driving wheels on the road surface becomes a predetermined target value. For example, JP-A-60-
Japanese Patent Laid-Open No. 128028 and Japanese Patent Laid-Open No. 63-166649 disclose that both brake traction control and engine traction control are performed.

On the other hand, various anti-skid brake devices for controlling the brake hydraulic pressure adjusting mechanism based on the slip condition of the wheels have been proposed and put into practical use in order to prevent the wheels from locking and the skid condition from occurring during braking of the vehicle. ing. For example, Japanese Laid-Open Patent Publication No. 1-197160 describes a system that performs both anti-skid brake control and traction control, and that traction control is stopped during anti-skid brake control. By the way, in those that perform anti-skid brake control and brake traction control, both brake hydraulic pressure adjustment mechanisms are control targets, so both these controls are executed by a common microcomputer, and as a safety measure during system down, It is general that these two controls are duplicated by two microcomputers having the same function, and mutual monitoring of both microcomputers is performed by mutual exchange of data. Usually, a microcomputer is often provided with a watchdog timer as a monitoring circuit for detecting an abnormal operation of the microcomputer by monitoring its operation step.

[0004]

When the antiskid brake control means, the brake traction control means and the engine traction control means are provided, two microcomputers having the same function are provided as the antiskid brake control means and the brake traction control means. However, it is costly to equip the microcomputer as engine traction control means in duplicate, and the control contents of this microcomputer are different from those of the former microcomputer. Therefore, it is not easy to monitor each other by exchanging data.

Moreover, it is desirable to stop the engine traction control when the system of the anti-skid brake control means and the brake traction control means is down, and to stop the anti-skid brake control and the brake traction control when the system of the engine traction control means is down. , The technology to realize this has not been proposed yet. An object of the present invention is to provide a slip control device for a vehicle that can stop the control of the anti-skid brake control means and the brake traction control means in response to a system down of the engine traction control means.

[0006]

According to another aspect of the present invention, there is provided a slip control device for a vehicle, comprising: an anti-skid brake control means for controlling a hydraulic pressure adjusting means for adjusting a brake hydraulic pressure based on a slip state of a wheel during braking; In a vehicle including brake traction control means for controlling the hydraulic pressure adjusting means based on a slip state and engine traction control means for controlling an output torque adjusting means of an engine based on a slip state of wheels, the anti-skid brake control is provided. Means and first and second microcomputers having the same function as brake traction control means,
A third microcomputer as the engine traction control means, a first monitoring circuit for monitoring the abnormality of the first and second microcomputers, and a second monitoring circuit for monitoring the abnormality of the third microcomputer. And a first stopping means for stopping the control of the anti-skid brake control means and the brake traction control means when the second monitoring circuit detects an abnormality.

According to a second aspect of the present invention, there is provided a vehicle slip control device according to the first aspect, further comprising second stopping means for stopping the control of the engine traction control means when the first monitoring circuit detects an abnormality. Is. A slip control device for a vehicle according to claim 3 is the device according to claim 1, wherein
The second monitoring circuit is configured to output an “L” level output signal when an abnormality is detected, and the first stopping means includes:
A first AND which is provided in the output circuits of the first and second microcomputers and receives the output signals of these microcomputers and the output signal of the second monitoring circuit and outputs the logical product of them.
It consists of a gate. A vehicle slip control device according to a fourth aspect is the device according to the second aspect, wherein the first monitoring circuit is configured to output an “L” level output signal when an abnormality is detected, and the second stopping means includes: The second AND gate is provided in the output circuit of the third microcomputer and receives the output signal of the microcomputer and the output signal of the first monitoring circuit and outputs a logical product of them.

[0008]

According to the present invention, the first and second microcomputers having the same function as the anti-skid brake control means and the brake traction control means and the third microcomputer as the engine traction control means are provided. The monitoring circuit monitors the abnormality of the first and second microcomputers, the second monitoring circuit monitors the abnormality of the third microcomputer, and the first stopping means uses the anti-skid when the second monitoring circuit detects the abnormality. The control of the brake control means and the brake traction control means is stopped.

In the second aspect, the second stopping means stops the control of the engine traction control means when the first monitoring circuit detects an abnormality. According to a third aspect of the present invention, the second monitoring circuit outputs an "L" level output signal when an abnormality is detected, and the first AND gate as the first stopping means is provided in the output circuits of the first and second microcomputers. Then, it receives the output signal of these microcomputers and the output signal of the second monitoring circuit, and outputs the logical product. According to another aspect of the present invention, the first monitoring circuit outputs an "L" level output signal when an abnormality is detected, and the second AND gate as the second stopping means is provided in the output circuit of the third microcomputer. It receives the output signal of the microcomputer and the output signal of the first monitoring circuit and outputs the logical product.

[0010]

According to the vehicle slip control device of the first aspect, the first monitoring circuit for the first and second microcomputers, the second monitoring circuit for the third microcomputer, and the first suspension. By providing the means, it is possible to reliably stop the control of the anti-skid brake control means and the brake traction control means when the engine traction control means is abnormal with a simple configuration.

According to the second aspect of the present invention, by providing the second stopping means, the control of the engine traction control means can be surely stopped when the antiskid brake control means and the brake traction control means are abnormal. .. According to the apparatus of claim 3, the first stopping means can have a simple structure including an AND gate. According to the apparatus of claim 4, the second stopping means can have a simple structure including an AND gate.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example in which the present invention is applied to a slip control device for an FF type vehicle, and as shown in FIG. 1, this vehicle has a left front wheel 1A, a right front wheel 1B,
A left rear wheel 1C and a right rear wheel 1D are provided, and an engine 2 is laterally arranged at the front of the vehicle body. The torque generated by the engine 2 is transmitted to the clutch 3, the transmission 4, and the differential gear 5. It is transmitted to the left front wheel 1A via the left drive shaft 6a and to the right front wheel 1B via the right drive shaft 6b. That is, the left and right front wheels 1A and 1B are driving wheels, and the left and right rear wheels 1C and 1D are driven wheels.

The brakes 7A, 7B, 7C and 7D provided on the four wheels 1A to 1D on the front, rear, left and right are hydraulic disc brakes, and the master cylinder 8 as a brake hydraulic pressure generation source has two discharge ports. The brake pipe 13 is a tandem type having 8a and 8b, and the brake pipe 13 extending from one discharge port 8a of the master cylinder 8 is branched into two in the middle, and the branch pipe 13a (the wheel cylinder in the caliper of the left front wheel brake 7A ) And branch pipe 1
3b is connected to the right rear wheel brake 7D. The brake pipe 14 extending from the other discharge port 8b of the master cylinder 8 is branched into two on the way, the branch pipe 14a is connected to the left rear wheel brake 7C, and the branch pipe 14b is connected to the right front wheel brake 1B. Has been done.

Electromagnetic hydraulic pressure adjusting valves 15a and 15b are connected to the left and right branch pipes 13a and 14b for the front wheels, respectively.
An electromagnetic opening / closing valve 16 is provided in the branch pipes 14a, 13b for the rear wheels.
a and 16b are connected to each other. The hydraulic pressure adjustment valve 15
a, 15b are brakes 7A, 7 from the master cylinder 8
B hydraulic pressure supply to B and the brake oil of the brakes 7A and 7B through the pipes 21a and 21b to the reservoir tank 2
The mode of opening to 2a, 22b is switched. The brake oil in the reservoir tank 22a is returned to the pipe 13 via the pump 23a, and similarly, the brake oil in the reservoir tank 22b is returned to the pipe 14 via the pump 23b.

The stepping force on the brake pedal 12 is
It is transmitted to the master cylinder 8 via a brake booster 11 as a booster. This booster 11 is basically the same as a known vacuum booster, but during anti-skid brake control and brake traction control, the booster 11 doubles even if the brake pedal 12 is not depressed as described later. It is configured to exert force. The booster 11 has a case 31 fixed to the vehicle body and the master cylinder 8, and inside the case 31, a first chamber 34 and a second chamber 35 are formed by a diaphragm 32 and a valve body 33 fixed to the diaphragm 32. Is defined in. Negative pressure (for example, intake negative pressure of the engine) is always introduced into the first chamber 34, and when the brake pedal 12 is not depressed, the second chamber 35 communicates with the first chamber 34,
The operation of the booster 11 is stopped. When the brake pedal 12 is stepped on, the atmosphere chamber is introduced into the second chamber 35 so that the diaphragm 32 moves toward the valve body 33.
At the same time, it is displaced forward and a boosting function is performed. The switching between the negative pressure supply and the atmospheric pressure supply to the second chamber 35 is basically performed by a valve mechanism incorporated in the valve body 33.

The portion of the valve body 33 will be described with reference to FIG. The valve body 33 has a power piston 41 fixed to the diaphragm, and the reaction disc 4 is provided in a recess 41 a of the power piston 41.
2 and the base end of the output shaft 43 (which corresponds to the input shaft of the master cylinder 8) are fitted together. A valve plunger 45 is mounted in the valve body 33 at the tip of the input shaft 44 connected to the brake pedal 12, and a vacuum valve 46 is provided behind the valve plunger 45.
Is provided.

A pressure introducing passage 50 is formed in the power piston 41. The pressure introducing passage 50 is always communicated with the space X around the valve plunger 45, and the space X is always communicated with the second chamber 35. The vacuum valve 46 is also seated on and off the valve seat 45a at the rear end of the valve plunger 45. In the above configuration, when a negative pressure is introduced into the pressure introducing passage 50 and when the brake pedal 12 is not operated, the state shown in FIG. 2 is obtained, and the vacuum valve 46 is moved to the valve seat by the biasing force of the springs 48 and 49. 45a, but seat 47
Are separated from. Therefore, the negative pressure from the pressure introducing passage 50 is introduced into the second chamber 35 through the space X, and the boosting action is not performed.

When the brake pedal 12 is depressed,
The input shaft 44, that is, the valve plunger 45 is forward (in the figure,
Moving to the left), the vacuum valve 46 first sits on the valve seat 47 to block the communication between the space X and the pressure introducing passage 50, and then the valve seat 45a is separated from the vacuum valve 46. This vacuum valve 4
Due to the separation between 6 and the valve seat 45a, the atmospheric pressure from the rear of the valve body 33 is introduced into the space X, and the second chamber 35 becomes the atmospheric pressure. As a result, the diaphragm 32 is displaced forward together with the valve body 33, the output shaft 43 is moved forward, and a boosting action is performed. The brake reaction force from the master cylinder 8 is transmitted to the valve plunger 45 and thus to the brake pedal 12 via the reaction disc 42. When the depression operation force of the brake pedal 12 is released, the return spring 36 returns to the state of FIG. 2 to prepare for the next boosting action.

The part described above is the same as the known vacuum booster, but in the device of this embodiment, the negative pressure of the first chamber 34 is applied to the pressure introducing passage 50 for traction control. It is configured to switch between the state of introducing and the state of introducing atmospheric pressure. That is, the first chamber 34 and the pressure introduction passage 50 are connected via the pipe 37, and the electromagnetic three-way switching valve 38 is connected to the pipe 37. This solenoid 3-way valve 38
Makes the pressure introducing passage 50 communicate with the first chamber 34 during demagnetization,
At the time of excitation, atmospheric pressure is introduced into the pressure introducing passage 50. When the switching valve 38 is excited and the atmospheric pressure is introduced into the pressure introducing passage 50, the space X, that is, the second chamber 35 becomes the atmospheric pressure without the depression operation of the brake pedal 12, and as a result, the boosting action is performed. As a result, brake hydraulic pressure is generated in the master cylinder 8.

Next, a control system related to the anti-skid brake control of the automobile, the brake traction control, and the engine traction control will be described with reference to FIGS. 1 and 3. As shown in FIGS. 1 and 3, a wheel speed sensor 61 for detecting the rotational speeds of the left and right front wheels 1A, 1B, respectively.
a, 61b, wheel speed sensors 61c and 61d that detect the rotational speeds of the left and right rear wheels 1C and 1D, respectively, a steering angle sensor 62 that detects the rotational angle of the steering wheel, and the accelerator pedal 10 is fully closed. Accelerator switch 63 that is turned on, and brake switches 64 and 65 that operate when the brake pedal 12 is depressed (switch 64).
Is a normally open type switch, and 65 is a normally closed type switch. Detection signals of these sensors and switches are supplied to the control device 60.

With respect to the control device 60, the detection signals from the wheel speed sensors 61a to 61d are waveform shaping circuits 6.
It is supplied to the input interface 68 after waveform shaping at 6,
The detection signal from the steering angle sensor 62 is the A / D converter 6
After being A / D converted at 7, the signal is supplied to the input interface 68, and the detection signals from the brake switches 64 and 65 are supplied to the input interface 68.
A first microcomputer 69, a second microcomputer 70, and a third microcomputer 71 are connected to the input interface 68. The first microcomputer 69 and the second microcomputer 70 are the same microcomputer having the same function, and are provided in duplicate for safety measures at the time of failure. The microcomputer 69, which executes skid brake control and brake traction control,
Reference numeral 70 indicates, for example, the same data such as the wheel speed of any wheel calculated on the basis of the detection signals from the wheel speed sensors 61a to 61d, and the data received from the other party at every moment. Mutual monitoring is performed by collating.

The third microcomputer 71 executes engine traction control, and this microcomputer 71 and the second microcomputer 70 are similar to the above, for example, the wheel speed sensor 61.
Mutual monitoring is performed by exchanging data such as the wheel speed of any wheel calculated based on the detection signals from a to 61d and collating the data received from the other party with the data calculated by oneself. However, the control program for the mutual monitoring is the microcomputer 69, 70, 71.
It is assumed that they are stored in each ROM. Furthermore, the first
A first monitoring circuit 72 for monitoring the runaway of the microcomputer 69 and the second microcomputer 70 is provided commonly to both the microcomputers 69 and 70, and the third monitoring circuit 72 is also provided.
A second monitoring circuit 73 for monitoring the runaway of the microcomputer 71 is provided.

The first monitoring circuit 72 corresponds to a so-called watch dog timer, and when an abnormality occurs in the operation of the first microcomputer 69 or the second microcomputer 70, both microcomputers 69,
A command signal for stopping their operation is supplied to 70, and an "L" level signal is output to its output line 72a. However, when both the microcomputers 69 and 70 are operating normally, an "H" level signal is output to the output line 72a. Second
The monitoring circuit 73 corresponds to a so-called watch dog timer as described above, and includes the third microcomputer 7
When an abnormality occurs in the operation of No. 1, an instruction signal for stopping the operation is supplied to the third microcomputer 71, and an "L" level signal is output to the output line 73a thereof. However, when the third microcomputer 71 is operating normally, an "H" level signal is output to the output line 73a.

Further, the output circuits of the first and second microcomputers 69 and 70 include both microcomputers 6
A first AND gate 74 which receives the output signals of 9, 70, the output signal of the first monitoring circuit 72, and the output signal of the second monitoring circuit 73 and outputs a logical product thereof (this is the first stopping means). Corresponding to the output signal of the microcomputer 71, the output signal of the first monitoring circuit 72, and the output signal of the second monitoring circuit 73 are output to the output circuit of the third microcomputer 71. A second AND gate 75 which receives as an input and outputs a logical product of them
(This corresponds to the second stopping means).

An output signal from the first AND gate 74 is output through an output interface 76 to drive circuits 78a and 78b for the hydraulic pressure adjusting valves 15a and 15b and drive circuits 78c and 78d for the open / close valves 16a and 16b. And a drive circuit 79 for the electromagnetic three-way switching valve 38. An output signal from the second AND gate 75 is output through an output interface 77 to an ignition timing control unit 80 of an engine control device 80 that controls the ignition and the fuel of the engine 2.
a and / or the fuel control unit 80b.

The first microcomputer 69 and the second microcomputer
The control content itself of the anti-skid brake control and the brake traction control, which are simultaneously and concurrently executed by the microcomputer 70 as the same content, is the same as the existing general anti-skid brake control and the brake traction control, which is not directly related to the present invention. Since they are the same, detailed description thereof will be omitted, but control programs for these controls are stored in the ROM of the first microcomputer 69 and the ROM of the second microcomputer 70, respectively, and similarly, the third microcomputer The control content itself of the engine traction control executed by 71 is
Since it is the same as the existing general engine traction control, which is not directly related to the present invention, its detailed description is omitted, but the control program for this control is stored in the ROM of the third microcomputer 71. And

The anti-skid brake control is
During braking, the locked state of each wheel is determined based on the vehicle speed and the wheel speed of each wheel, and the brake hydraulic pressure is increased, the hydraulic pressure is maintained, and the brake hydraulic pressure is reduced so that the slip ratios of the four wheels reach a predetermined target slip ratio. Is a control for repeating the control of a predetermined pattern, and the brake traction control increases the brake hydraulic pressure to increase the slip ratio when the slip ratio of the driving wheels becomes equal to or more than a predetermined start threshold value. The control is to control the brake hydraulic pressure so that the slip ratio becomes equal to or less than a predetermined continuation threshold value for brake traction control, and the engine traction control is such that the slip ratio of the driving wheels is a predetermined value. The engine output torque is reduced by retarding the ignition timing of the engine when the threshold value for starting is exceeded, and / or the fuel cap of the engine is reduced. By achieving reduction of the slip rate by or reduces the engine output torque, a control for controlling the engine output torque so that the subsequent slip rate becomes less than a predetermined continuation threshold value for the engine traction control.

The operation of the slip control device according to this embodiment will be described. When the first to third microcomputers 69 to 71 are operating normally, the "H" level signal is output from the first and second monitoring circuits 72 and 73, and the first and second computers are connected. 69, 70
Since the same control signal is output from the first AND gate 74, the first and second microcomputers 69, 7
A control signal of 0 is output, and the first and second microcomputers 69 and 70 perform anti-skid brake control and brake traction control. Then, a control signal for engine traction control output from the third microcomputer 71 is output from the second AND gate 75, and engine traction control is performed.

Here, when the first microcomputer 69 or the second microcomputer 70 starts to operate abnormally due to system down, the first monitoring circuit 72 detects it and causes the first and second microcomputers 69 and 70 to operate. A stop command signal is supplied to both microcomputers 69,
70 is stopped and the first monitoring circuit 72 is set to "L".
Since the level signal is output to the first AND gate 74 and the second AND gate 75, the outputs of both AND gates 74 and 75 become "L" level, and the control by the three microcomputers 69 to 71 is stopped. On the other hand, when the system of the third microcomputer 71 goes down and starts to operate abnormally, the second monitoring circuit 73 detects it and supplies a stop command signal to the third microcomputer 71 to operate the third microcomputer 71. Along with stopping
The second monitoring circuit 73 outputs an “L” level signal to the first AND gate 74 and the second AND gate 75, so that the outputs of both AND gates 74 and 75 become “L” level,
The control by the three microcomputers 69 to 71 is stopped.

As described above, when any one of the microcomputers fails, the anti-skid brake control and brake traction control by the first and second microcomputers 69 and 70 and the engine traction control are automatically stopped. As a result, system failure countermeasures are thoroughly taken, and reliability and safety can be improved. The first monitoring circuit 72 may be incorporated in the first microcomputer 69 or the second microcomputer 70, and as shown in FIG.
Even if the monitoring circuits 72A, 72B and 73 associated with the three microcomputers 69 to 70 are provided and connected as shown in the drawing, the same operation as described above can be obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an automobile slip device according to an embodiment.

FIG. 2 is a cross-sectional view of a main part of the brake booster of FIG.

FIG. 3 is a block diagram of a control system of the slip control device of FIG.

FIG. 4 is a block diagram of a main part of a control system of a slip control device according to a modification.

[Explanation of symbols]

 60 control device 69 1st microcomputer 70 2nd microcomputer 71 3rd microcomputer 72 1st monitoring circuit 73 2nd monitoring circuit 74 1st AND gate 75 2nd AND gate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keizumi Masu, No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Nardeck Co., Ltd. (72) No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Nardeck Co., Ltd.

Claims (4)

[Claims] 1. An anti-skid brake control means for controlling a hydraulic pressure adjusting means for adjusting a brake hydraulic pressure based on a slip state of a wheel during braking, and a brake traction control for controlling the hydraulic pressure adjusting means based on a slip state of a wheel. A vehicle having an engine traction control means for controlling an output torque adjusting means of an engine based on a slip state of a wheel, a first and a first function having the same function as the anti-skid brake control means and the brake traction control means. Two microcomputers, a third microcomputer as the engine traction control means, a first monitoring circuit for monitoring abnormalities of the first and second microcomputers, and for monitoring abnormalities of the third microcomputer A second monitoring circuit, and the second monitoring circuit When detects an abnormality, the slip control apparatus for a vehicle characterized by comprising a first stop means for stopping the control of the antiskid brake control means and the brake traction control means. 2. The vehicle slip control device according to claim 1, further comprising a second stop means for stopping the control of the engine traction control means when the first monitoring circuit detects an abnormality. Slip control device. 3. The vehicle slip control device according to claim 1, wherein the second monitoring circuit is configured to output an “L” level output signal when an abnormality is detected, and the first stopping means includes a first And a first microcomputer which is provided in an output circuit of the second microcomputer and which receives an output signal of the microcomputer and an output signal of the second monitoring circuit and outputs a logical product thereof.
A vehicle slip control device comprising an AND gate. 4. The slip control device for a vehicle according to claim 2, wherein the first monitoring circuit is configured to output an “L” level output signal when an abnormality is detected, and the second stopping means includes a third A slip control device for a vehicle, comprising a second AND gate which is provided in an output circuit of a microcomputer and receives an output signal of the microcomputer and an output signal of the first monitoring circuit and outputs a logical product thereof.