JPH0364337B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention increases braking pressure without stepping on the brake when the driving wheels are spinning, and when the wheel rotation decreases due to this pressurization, the pressure is reduced. This invention relates to a device that controls wheel slippage by repeating operations.

[Prior art]

Conventionally, there are devices called non-slip differentials that control the slippage of the drive wheels that occurs when a vehicle starts on a snowy road, on sand, or suddenly starts.
In this device, the rear shaft is connected by a clutch plate, so when one wheel starts to spin, the resistance of the clutch plate prevents the slip to some extent, and the torque of the other wheel can be increased. However, the vehicle does not have any control function to prevent the two driving wheels from spinning, and the driver has no choice but to rely on the driving skills of the driver.

Recently, a device has been developed that uses a so-called anti-skid control device to control the brake pressure when slipping of the drive wheels is detected, and is disclosed in, for example, Japanese Patent Laid-Open No. 58-202142.

However, conventional drive wheel slip control is
There are problems with its responsiveness, structure of mechanical parts, and scale, and it has not yet been put into practical use.

[Summary of the Invention] The present invention has been made in consideration of the above-mentioned points, and is configured so that braking is controlled independently for both wheels of the driving wheels, and the wheel slip is controlled by the acceleration of the wheel speed or A wheel that can prevent slippage by detecting the amount of slip between the non-driving wheel speed and increasing the braking pressure, and reducing the braking pressure based on the deceleration of the wheel speed or the amount of slip between the non-driving wheel speed. The purpose of the present invention is to provide a idling control device.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings, but before that, the basic configuration of the present invention will be explained with reference to FIG. In the figure, 1 is a driving wheel, 2 is a driving wheel speed detection means, 3 is an acceleration/deceleration calculating means for calculating the acceleration/deceleration of the wheel based on the output of the detection means 2, and 4 is a driving wheel speed detecting means.
is a small vibration in the vertical direction of the car body (jadder)
Vibration detection means detects the vibration of the drive wheel 1 because the drive wheel 1 generates a large acceleration/deceleration in a short period of time due to the occurrence of this phenomenon, and 5 is a brake that brakes the drive wheel 1. 6 is a brake of the brake 5. a pressure actuator that increases the braking pressure; 7 a pressure reducing actuator that reduces the braking pressure of the brake 5; 8 at least one non-driving wheel; 9 non-driving wheel speed detection means for detecting the wheel speed of the non-driving wheel 8; Reference numeral 10 denotes pressurization signal determining means for determining that the driving wheel speed is greater than or equal to a predetermined value with respect to the non-driving wheel speed; 11 is a depressurization signal determining means that similarly determines that the driving wheel speed is less than or equal to the predetermined value;
12 is a pressurizing signal output means for outputting a drive signal to the pressurizing actuator 6 when the acceleration of the driving wheel 1 is above a predetermined value and there is no vibration; 13 is a pressurizing signal output means when the deceleration of the driving wheel 1 is below a predetermined value. pressure reduction signal output means for outputting a drive signal to the pressure reduction actuator 7;
Reference numeral 14 indicates that the pressure signal determining means 10 outputs a signal and also outputs a signal for driving the pressure actuator 6 when there is no output signal of the pressure reduction signal output means 13 and a vibration signal of the vibration detection means 4, and also outputs a signal for driving the pressure actuator 6. The means 11 outputs a signal and is a pressure reduction signal output determination means that outputs a signal to drive the pressure reduction actuator 7 when there is no output from the pressure signal output means 12, and drives the control device for the drive wheel 1 consisting of these. It is provided independently for both wheels of the wheel 1, and controls the idling of both wheels of the drive wheel 1 using acceleration/deceleration and slip amount.

FIG. 2 shows the specific configuration of this embodiment, 15a
is the front right brake, 15b is the front left brake,
15c is rear right brake, 15d is rear left brake,
Reference numerals 16a to 16d are wheel speed sensors respectively disposed on the respective brakes 15a to 15d, and wheel speed signals from the respective wheel speed sensors 16a to 16d are sent to the control circuit 1.
7 is input. The microcomputer built into the control circuit 17 calculates the speed of each wheel based on the control program described later, calculates the acceleration/deceleration of the wheel speed of the driving wheels (front wheels), and also calculates the wheel speed of the non-driving wheels (rear wheels). The amount of slip is also calculated. When wheel slippage is determined based on acceleration/deceleration and slip amount, signals are output to various control actuators described below. This signal operates the brake pressure backflow prevention actuator 18, and if pressurization is required, pressurization actuator 19a or 19b is actuated, and conversely, if pressure reduction is required, pressure reduction actuator 20 is actuated.
a or 20b. On the other hand, braking pressure is constantly increased and stored in a pressure accumulator 23 by a motor 22 and the like which are connected to a device for detecting a decrease in braking pressure from a storage chamber 21 storing brake fluid.
In the pressurized state, the braking pressure is supplied from the pressure accumulator 23 to the front wheel brakes 15a, 15b through the pressurizing actuator 19a or 19b. On the other hand, in the case of a reduced pressure state, the braking pressure passes through the reduced pressure actuator 20a or 20b and returns to the storage chamber 21. When both the pressure adjustment actuators 19 and 20 are not operating, the current braking pressure is maintained. Note that this embodiment is a front-wheel drive vehicle.

Next, the operation of the microcomputer built in the control circuit 17 will be explained based on the flowchart shown in FIG. First, start and step
After initialization in step S1, the wheel speed V _R of the rear wheels (non-driving wheels) is calculated in step S2. When the wheel speeds of both rear wheels are input as in this embodiment, the speed of one wheel is representative. The method of calculating the wheel speed is to measure the number of wheel speed pulses P input within a certain period of time, and calculate V _R = KP from the time T ₁ when the pulse was first input and the time T ₂ when the pulse was input last. /T ₂ −T ₁ ...There is a method of measuring the period using the formula (1). K is a constant. In step S3, the wheel speed _VFR of the front right wheel is calculated using the same method. In step S4, the acceleration/deceleration _GFR of the front right wheel is calculated. This calculation is performed as follows. Since the microcomputer executes S2 to S21 at a certain period of time, the above wheel speed V _FR is used for acceleration/deceleration, and the formula G _FR = V _FR (N) - V _FR (O) ......(2) is used. It can be replaced with. Here, V _FR (N)
is the current wheel speed, and V _FR (O) is the wheel speed one cycle ago of the microcomputer. If G _FR > 0, the vehicle is currently accelerating; conversely, if G _FR <0, the vehicle is decelerating. Similarly, in step S5, the wheel speed of the front left wheel V _FL
In step S6, the acceleration/deceleration G _FL of the front left wheel is calculated.
Calculate. Next, in step S7, vibration detection is performed, details of which will be described later. In step S8, it is determined whether the number of vibrations n is zero. If n=0, it is determined in step S9 whether the acceleration/deceleration _GFR of the front right wheel is greater than a predetermined value _α1 . If G _FR α _{is 1} , a signal to drive the backflow prevention actuator 18 is output in step S10, and a signal to drive the pressure actuator 19 is output in step S11, and the signal is stopped so that the pressure reduction actuator 20 is deactivated. . This is the pressurization mode. Also, step
If G _FR < α ₁ in S9, proceed to step S12, and G _FR α ₂
Determine whether or not. If G _FR α ₂ , step S13
outputs a signal to drive the pressure reducing actuator 20 and stops the signal so as to deactivate the pressure actuator 19. This is the decompression mode. If G _FR > α ₂ , it is determined in step S14 whether the difference between V _FR and V _R , that is, the amount of slip, is greater than a predetermined value e ₁ , and if V _FR - V _R e ₁ , the pressurization mode is selected. . In step S15, it is determined whether the slip amount is less than or equal to a predetermined value _e2 . If V _FR −V _R e ₂ , it is the pressure reduction mode, and if V _FR −V _R >e ₂ , it is the current braking pressure holding mode. In step S16, the number of vibrations n is set to the predetermined number N.
Determine whether or not the above is true. If nN, the pressure reduction mode is selected. In step S17, it is determined whether the acceleration/deceleration _GFR is less than or equal to a predetermined value _α2 . If G _FR α ₂ , it becomes decompression mode. In step S18, it is determined whether the slip amount is less than a predetermined value, and if V _FR -V _R e ₂ , the pressure reduction mode is entered. Next, in step S19, the front left wheel is processed into pressurization, depressurization, and holding modes in the same way as the front right wheel. In step 20, it is determined whether or not the above-described control has been completed. The end of the control is determined based on, for example, that the rear wheel speed has exceeded a predetermined value, that the brake pedal has been depressed, that the pressure reduction mode has continued for more than a predetermined time, and so on. When it is determined that the control has ended, the backflow prevention actuator 1 is activated in step S21.
Stop the signal so that 8 is inactive. step
After completion of S21, or if it is determined in step S20 that the control is not completed, the process returns to step S2 and executes each step again.

Here, the vibration processing will be explained using FIGS. 4 and 5. Assume that the wheel speed of one of the driving wheels changes over time as shown by waveform 24 in FIG. 4a. For this wheel speed, the acceleration signal has a waveform 25 in FIG. 4b, and the deceleration signal has a waveform 26 in FIG. 4c. Since the occurrence of alternating acceleration and deceleration signals within a short period of time is regarded as vibration, the number of vibrations n changes as shown in FIG. Next, the control program will be explained using the flowchart shown in FIG. In step S22, it is determined whether the acceleration _GFR of the front right wheel is greater than or equal to a predetermined value _α1 . If G _FR α ₁ , it is determined in step S23 whether or not it is at the time of acceleration rise. If it is a rising time, it is determined in step S24 whether or not the acceleration interval time t is less than a predetermined time T. If t<T, it is determined in step S25 whether the deceleration flag GFLAG is set. If it has been set, the number of vibrations n is set to n=n+1 in step S26. If not set, n=0 is set in step S27. step
In S29, the interval time t is set to 0. step
In S30, reset GFLAG. In step S31, the interval time t=t+1 is set, and in step S32, it is determined whether the deceleration _GFR is less than or equal to a predetermined value _α2 , and _{GFR is}
If α _{is 2} , GFLAG is set in step S33.
The same control is performed for the front left wheel, and the number of vibrations n is determined for the front left and right wheels.

FIG. 6 is a time chart showing the operation of the above-mentioned device. As shown in FIG. 6a, it is assumed that the wheel speed on one side of the front wheels is waveform 27 and the wheel speed on one side of the rear wheels is as shown in waveform 28. Using a microcomputer, the acceleration signal becomes waveform 29 in figure b, the deceleration signal becomes waveform 30 in figure c, and the slip is determined by the rear wheel speed.
There are two types of waveforms 31 and 32 in the figure, and from this slip wheel speed, the slip amount signal becomes waveform 3 in figures d and e.
It is calculated as 3,34. Therefore, the brake pressure is generated by the acceleration signal 29 as shown in the waveform 35 in the diagram f.
The pressurizing mode is set according to the slip amount signal 33 and the number of vibrations n, and the pressurizing mode is set according to the deceleration signal 30 and the slip amount signal 34. The current braking pressure holding mode is when all signals are not output, and when the number of vibrations n≠0 and the deceleration signal 30 and slip amount signal 34 are not output.

〔Effect of the invention〕

As described above, in the present invention, wheel slipping is detected and brake pressure is controlled according to the amount of slip and acceleration/deceleration, thereby preventing slipping and providing smooth vehicle running. Furthermore, wheel torque that is wasted due to idling can be more appropriately utilized as driving torque. Furthermore, small vertical vibrations of the vehicle body that may occur due to brake pressure control can be detected based on acceleration/deceleration detection of the drive wheels, and can be prevented. The present invention provides anti-skid control in which when the wheels are about to lock up during braking, the braking pressure is reduced by operating a pressure reducing actuator, and when the wheel rotation is restored due to this pressure reduction, the braking pressure is restored again by operating the pressurizing actuator. It can also be used for

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of the device of the present invention, FIG. 2 is a specific configuration diagram showing an embodiment of the device of the present invention, FIG. 3 is a flowchart showing the operation of the microcomputer according to the present invention, and FIG. 4 5 is a flowchart for detecting wheel vibration according to the present invention, and FIG. 6 is an explanatory diagram of the operation of the apparatus of the present invention. 1... Drive wheel, 2... Drive wheel speed detection means, 3
... Acceleration/deceleration calculation means, 4... Vibration detection means, 5
... Brake device, 6 ... Pressure actuator, 7 ...
Depressurizing actuator, 8... Non-driving wheels, 9... Non-driving wheel speed detection means, 10... Pressurizing signal determining means, 11... Depressurizing signal determining means, 12... Pressurizing signal output means, 13... Depressurizing Signal output means, 14...
... Pressure increase/decrease signal output determination means. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. Each drive wheel speed detection means that detects the wheel speed of each drive wheel of the vehicle, each acceleration/deceleration calculation means that calculates the acceleration/deceleration of each drive wheel based on the drive wheel speed, and each drive shaft that is large in a short period of time. Each vibration detection means detects the vibration of each drive wheel by generating acceleration/deceleration and repeating these, each brake that brakes each drive wheel, each pressurizing actuator that increases the braking pressure of each brake, respectively. each pressure reducing actuator that respectively reduces the braking pressure of each brake; non-driven wheel speed detection means that detects the wheel speed of at least one non-driven wheel; and each driven wheel speed is equal to or higher than a predetermined value with respect to the non-driven wheel speed. each pressurization signal determining means for determining, respectively, that each of the driving wheel speeds is below a predetermined value with respect to the non-driving wheel speed; and each pressurization signal output means outputs a drive signal to each pressurization actuator when there is no vibration, and each outputs a drive signal to each pressure reduction actuator when the deceleration of each drive wheel speed is below a predetermined value. When the pressure reduction signal output means and the pressure signal determination means output a signal and the pressure reduction signal output means and the vibration detection means have no output, the pressure reduction signal output means outputs a signal to drive each pressure actuator, and the pressure reduction signal determination means outputs a signal. What is claimed is: 1. A wheel slip control device comprising pressure reduction signal output determination means for outputting a signal for driving each pressure reduction actuator when there is no output from the pressure signal output means.