JPH01145242A - Drive power controller for vehicle - Google Patents

Abstract

PURPOSE:To facilitate the release of stack by prohibiting the drive power reduction control when the accelerator operating quantity is over a prescribed value and the car body speed is less than a prescribed value, in the drive power reduction control in case of the generation of a drive wheel slip. CONSTITUTION:A drive wheel speed detecting means (a) for detecting the revolution speed of a drive wheel, car body speed detecting means (b) for detecting the traveling speed of a vehicle, and an accelerator operation quantity detecting means (c) are installed. An actual slip rate calculating means (d) calculates the actual slip rate between a tire and a road surface from the drive wheel speed and the car body speed. Then, the actual slip rate is compared with a prescribed set slip rate, and when the actual slip rate exceeds the set slip rate, a drive power control means (e) executes the drive power reduction control and suppresses the drive wheel slip. Further, when the accelerator operation quantity of an accelerator operating element is over a prescribed value, and the state in which the car body speed is less than a prescribed value continues for a prescribed time, a prohibiting means (f) prohibits the drive power reduction control.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle driving force control device that suppresses slippage of drive wheels.

(Prior Art) As a conventional vehicle driving force control device, for example, a device described in Japanese Patent Application Laid-Open No. 60-43133 is known.

This conventional device is configured to forcibly close the throttle valve and reduce the driving force if the slip ratio is larger than a predetermined setting value when driving wheel slip occurs.

(Problems to be Solved by the Invention) However, such a vehicle driving force control device has a configuration in which control is always performed to reduce the driving force (engine output) when drive wheel slip occurs. As a result, there were problems as described below.

■ If the drive wheels get stuck in mud or deep snow, it is often impossible to escape by detecting drive wheel slip and reducing the driving force.

In particular, if the excessive slip of the tires scrapes the road surface, revealing a high-μ road surface from below, and attempting to escape using that surface, there is no particular possibility of this happening.

■ Mechanic LSD and viscous LS between the left and right drive wheels
In a vehicle equipped with a differential limiting mechanism such as D, when one wheel is stuck, even if you try to escape by distributing the drive force to the one wheel on the high μ road side by engaging the clutch, the drive wheel on the stuck side will spin and the drive will be lost. It was detected that the wheels were slipping, and it was not possible to escape by reducing the driving force.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and to achieve this purpose, the present invention employs the following solving means.

The solving means of the present invention will be explained with reference to the claim correspondence diagram shown in FIG.
and vehicle speed detection means for detecting the vehicle speed; accelerator operation amount detection means C for detecting the operation amount of the accelerator operator;
an actual slip rate calculating means d for calculating an actual slip rate between the tires and the road surface based on the driving wheel speed and the vehicle body speed; and suppressing driving wheel slip when the actual slip rate exceeds a predetermined set slip rate. The driving force control means e performs driving force reduction control to reduce the driving force when the accelerator operation amount is equal to or higher than a predetermined value and the vehicle body speed is equal to or lower than a predetermined value for a predetermined period of time. A driving force reduction control inhibiting means f for prohibiting reduction control is provided.

Note that the driving force control means e refers to a means capable of reducing the driving force, and specifically includes a throttle valve opening/closing control device,
The fuel cut device 5 is a means that combines one or more of a flame timing control device, a brake device, etc.

(Function) When the drive wheels get stuck in mud or deep snow, or when a mechanic LSD or viscous LS is used between the left and right drive wheels.
When one wheel of a vehicle equipped with a differential limiting mechanism such as D is stuck, the driving force control means e performs driving force reduction control to suppress drive wheel slip when the actual slip rate exceeds a predetermined set slip rate. Even if the accelerator operation amount is greater than a predetermined value and the vehicle speed is less than or equal to a predetermined value for a predetermined period of time, the driving force reduction control inhibiting means will be activated. Force reduction control is prohibited.

Therefore, when the drive wheels get stuck in mud, deep snow, etc., it is possible to get out of the stuck state with a driving force corresponding to the amount of accelerator operation.

In particular, it is also possible to escape by exposing a high μ road surface from below by scraping the road surface with excessive tire slip.

In addition, there is a mechanic LSD and viscous L between the left and right drive wheels.
In a vehicle equipped with a differential limiting mechanism such as an SD, when one wheel is stuck, driving force is distributed according to the amount of hair accelerator operation of one wheel on the high μ road side by engaging the clutch, and the vehicle can escape from the stuck state.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, a driving force control device applied to a rear wheel drive vehicle will be taken as an example.

First, the configuration of the embodiment will be explained.

The power train P of a rear wheel drive vehicle to which the driving force control device A of the embodiment is applied is as shown in FIG.
, transmission 11, propeller shaft 12, rear differential 13, rear drive shaft 14
．． 15, rear wheels 16.17.

Front wheels 18,19 are non-drive wheels.

The driving force control device A of the embodiment includes an accelerator pedal 20 which is an accelerator operator, and a throttle valve 22 provided in a throttle chamber 21 which is an intake system of the engine IO.
This control device is provided between the accelerator pedal 20 and the throttle valve 22 in place of a mechanical connection means such as an accelerator control wire, and uses a rear wheel rotation speed sensor 30. as an input sensor. Right front wheel rotation speed sensor 31. A left front wheel rotation speed sensor 32 is provided, a throttle valve control circuit 34 is provided as an arithmetic processing means, and a step motor 35 is provided as a throttle actuator.

The rear wheel rotation speed sensor 30 is a drive wheel speed detection means,
The rear wheel rotation speed sensor 30 is provided on the human power shaft of the rear differential 13 and outputs a rear wheel rotation signal (vr) according to the rear wheel rotation speeds V and I. When a sensor or the like is used and a pulse signal is output as the rear wheel rotation signal (vr), in the human power interface circuit 341 in the throttle valve control circuit 34, the F
The /V converter converts it into a voltage according to the frequency of the pulse signal, and the A/D converter converts the voltage value into a digital value, which is read into the CPU 342 and memory 343.

The right front wheel rotation speed sensor 31 and the left front wheel rotation speed sensor 3
Reference numeral 2 denotes vehicle speed detection means, which is provided at each axle portion of the front wheels 18 and 19.

A right front wheel rotation signal (v f r) and a left front wheel rotation signal (v f r ) according to the right front wheel rotation speed VFR and the left front wheel rotation speed VFL
v f Q) is output.

Note that signal conversion for reading the output signals from the double-sided wheel rotation speed sensors 31 and 32 by the CPU 342 of the throttle valve control circuit 34 is performed in the same manner as in the rear wheel rotation speed sensor 30.

The accelerator potentiometer 33 is a means for detecting the absolute accelerator operation amount β, is provided at the position of the accelerator pedal 20, and outputs an absolute accelerator operation amount signal (I2) corresponding to the absolute accelerator operation amount a.

Note that since the output signal from the accelerator potentiometer 33 is an analog signal based on a voltage value, it is converted into a digital value by the A/D converter of the input interface circuit 341 and read into the CPU 342 and the memory 343.

The throttle valve control circuit 34 processes input information from the input sensor and information temporarily or pre-stored in the memory 343 according to a predetermined arithmetic processing procedure, and controls the step motor 35, which is a throttle actuator.
An electronic circuit centered on a microcomputer that outputs a pulse control signal (C) to the human interface circuit 341. CPU (Central Processing Unit) 342. Memory (RAM)

ROM)343. An output interface circuit 344 is provided.

The step motor 35 is an actuator that opens and closes the throttle valve 22, and includes a rotor and a plurality of stators having excitation windings, and rotates in the forward and reverse directions by applying pulses to the excitation windings. Rotate one step at a time.

Next, the operation of the embodiment will be explained.

First, the flow of the throttle valve opening/closing control operation in the CPU 342 will be described with reference to the main routine flowchart shown in FIG. 3 and the subroutine flowchart shown in FIG. 4.

Note that the processing in the main routine of FIG.
This is a fixed time interrupt process started at 0 m5ecl, and the process in the subroutine shown in FIG. 4 is started as appropriate within the main routine according to the signal output cycle to the step motor 35 determined by this fixed time interrupt. oci(
This is an output conveyor (interconnected) interrupt process.

(B) Initial Settings The main routine shown in Figure 3 starts when the engine key is inserted into the key cylinder and the ignition switch is turned from OFF to ON. A determination is made (step 100), and the process proceeds to the next initialization step 101.

In this initialization step 101, all information set during the previous run is cleared.

(b) Slip rate calculation process First, in step 102, each rotation speed sensor 30, 31
．． Based on input signals from 32, the rear wheel rotation speed vR1, right front wheel rotation speed VFR, and left front wheel rotation speed VFL are read.

In step 103, the front wheel rotation speed vF is calculated from the right front wheel rotation speed VFR and the left front wheel rotation speed vFL.

The calculation formula for the front wheel rotational speed vF is: , and is determined by the average value.

Next, in step 104, the slip rate S is calculated.

be.

(C) Driving Force Control Process First, in step 105, the accelerator operation amount β and the actual step number S T EP used in the process described later are read.

In step 106, the slip rate S is set to the set slip rate S.
. (for example, 0.1), and if S≦So and NO is determined, the process proceeds to step 107 as a normal control pattern, and based on the accelerator operation N2 read in step 105, The target step number 5TEP* is calculated as a value shown in the characteristic line described in the step.

Also, in step 110, S > So and YES
If it is determined that
After passing through steps 08 to 112), the process proceeds to step 113 unless the control prohibition condition is satisfied, and in order to perform a slip suppression control piece that closes the throttle valve 22 in the fully open direction as a slip suppression control pattern, the target step RS is
T E P * is set to zero.

Here, the driving force reduction control prohibition processing from step 108 to step 112 will be described.

In step 1O8, it is determined whether the accelerator operation ring 2 exceeds a set accelerator operation amount of 2° (for example, 2°=%).

In step 109, the front wheel rotation speed v1, which is the vehicle speed, is set to the set rotation speed V, (for example, V FO=Okm/h
) or less, in step 110, a stuck state timer is read and it is determined whether a predetermined time (for example, 2 seconds) has elapsed.

In step 111, the timer value of the stuck state timer is increased (incremented).

In step 112, the stuck state timer is returned to zero (cleared).

That is, when the accelerator operation amount condition (step 108) and the vehicle speed condition (step 109) are satisfied and a predetermined time has elapsed, the process proceeds from step 110 to step 107, and the driving force reduction control is turned off. Furthermore, the accelerator operation amount condition (step 108) and vehicle speed condition (step 1) are
Even if the condition 09) is satisfied, it may be possible to escape from the stack using slip suppression control, so unless the condition is satisfied for a predetermined period of time, driving force reduction control will not be prohibited.

In step 114, the deviation ε is the target step number 5TEP.
The actual step number 5TEP is subtracted from * (calculated by this), and based on the deviation ε obtained by this calculation, the motor speed of the step motor 35 is calculated, forward rotation, reverse rotation, and holding are determined, and the 001 interrupt routine is The starting cycle is determined (step 115), and according to the operation control details of the step motor 35 set in step 115, the starting cycle is determined as 00.
1 interrupt routine (FIG. 4) is activated (step 116).

Next, a flowchart of the oci interrupt routine will be described with reference to FIG.

First, it is determined whether it is time to output a holding command to maintain the state of the step motor 35 (step 300).
), when the holding command is output, the step motor 3
The stator side excitation state of No. 5 is maintained (step 301).

In addition, when the holding command is not output, the step motor 3
It is determined whether or not it is time to output a reversal command to reverse the rotation speed (step 302), and when the reversal command is output, 5TEP should be set to 5TEP-1 (step 303).
), STE, and P-1 are output to the step motor 35 (step 301). Furthermore, when outputting a normal rotation command to rotate the step motor 35 in the normal direction, 5T
Set EP to 5TEP+1 step 304), 5
The pulse signal that obtains TEP+1 is sent to the step motor 35.
(Step 3゜1).

Note that this oci interrupt routine is performed in step 11 above.
It is repeated within the main routine startup cycle according to the startup cycle set in step 7.

Next, the effect during driving will be described.

(b) When S≦30 If the slip rate is S≦So and no drive wheel slip occurs, step 106 to step 107 → step 11
The flow of the normal control pattern proceeds to Step 4, and the throttle valve 2 is adjusted to an opening degree corresponding to the position where the accelerator pedal 20 is depressed.
2 is controlled to open and close.

(b) When S>S When starting, accelerating, or driving on a road with a low friction coefficient, when the slip rate is S>So and drive wheel slip occurs, from step 106 to step 113→ Step 114
The flow of the slip suppression control pattern advances to , and driving wheel slip is suppressed by closing the throttle valve 22.

In addition, when a drive wheel gets stuck in mud or deep snow, or when one wheel gets stuck in a vehicle equipped with a differential limiting mechanism such as a mechanic LSD or viscous LSD between the left and right drive wheels, the slip rate may decrease to S. >So, the accelerator operation amount condition (step 108) and the vehicle speed condition (step 109) are satisfied, and when a predetermined time has passed, the process proceeds from step 110 to step 107, and the slip ratio is S.
>So, the driving force reduction control is prohibited and the normal control pattern after step 107 is resumed.

Therefore, when the drive wheels get stuck in mud or deep snow, it is possible to get out of the stuck state with a driving force corresponding to the accelerator operation amount 2.

In particular, it is also possible to escape by exposing a high μ road surface from below by scraping the road surface with excessive tire slip.

In addition, there is a mechanic LSD and viscous L between the left and right drive wheels.
In a vehicle equipped with a differential limiting mechanism such as an SD, when one wheel is stuck, the clutch is engaged to distribute driving force according to the single wheel hair accelerator operating voltage °C on the high μ road side, allowing the vehicle to escape from the stuck state.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may include design variations within the scope of the invention. included.

For example, in the example, a throttle valve opening/closing control device was shown as an example of driving force control (distributing means), but it is also possible to use a fuel cut device, adjust the ignition timing to reduce engine output, or use the brakes to reduce the engine output. The driving force may be reduced by other means, such as applying braking force to the wheels, or by a combination of means.

Further, as the throttle opening/closing control, it is also possible to use a device that performs slip suppression by map fall control, as described in specification δ of Japanese Patent Application No. 157389/1989, previously filed by the present applicant.

(Effects of the Invention) As described above, the vehicle driving force control device of the present invention includes a driving wheel speed detecting means for detecting the driving wheel speed, a vehicle body speed detecting means for detecting the vehicle body speed, an accelerator operation amount detection means for detecting an operation amount of an accelerator operator; an actual slip ratio calculation means for calculating an actual slip ratio between the tires and the road surface based on the driving wheel speed and the vehicle body speed; a driving force control means that performs driving force reduction control to suppress driving wheel slip when a set slip rate is exceeded; Since the means is characterized by comprising a driving force reduction control inhibiting means that prohibits the driving force reduction control if the driving force reduction control continues for a predetermined period of time, it is possible to prevent the drive wheel from getting stuck in mud or deep snow. Sometimes, it is possible to escape from a stuck state with the driving force that corresponds to the amount of accelerator operation.

In particular, it is also possible to escape by exposing a high μ road surface from below by scraping the road surface with excessive tire slip.

In addition, there is a mechanic LSD and viscous L between the left and right drive wheels.
When one wheel is stuck on a small mountain equipped with a differential limiting mechanism such as SD, the clutch engagement distributes the driving force according to the single wheel hair accelerator operation voltage on the high μ road side, making it possible to escape from the stuck state. .

[Brief explanation of the drawing]

Fig. 1 is a claim-corresponding diagram showing a vehicle driving force control device of the present invention, Fig. 2 is an overall view showing a driving force control device of an embodiment of the present invention, and Fig. 3 is a diagram showing a throttle valve control circuit of the embodiment. Flowchart diagram showing the main routine of control operation, No. 4
The figure is a flowchart showing a subroutine of control operation in the throttle valve control circuit of the embodiment. a...Drive wheel speed detection means b...Vehicle speed detection means C...-Accelerator operation amount detection means d...Actual slip rate calculation means e...Driving force control means f...Driving force reduction Control prohibition means Figure 1

Claims (1)

[Scope of Claims] Drive wheel speed detection means for detecting drive wheel speed; vehicle body speed detection means for detecting vehicle body speed; accelerator operation amount detection means for detecting an operation amount of an accelerator operator; and said drive wheel speed. an actual slip rate calculation means for calculating an actual slip rate between the tires and the road surface based on the vehicle speed and the vehicle body speed; and a driving force reduction device that prohibits driving force reduction control if the accelerator operation amount is equal to or greater than a predetermined value and the vehicle body speed is equal to or less than a predetermined value for a predetermined period of time. A vehicle driving force control device comprising: control prohibition means.