JPS61247521A - Skid controller for vehicle - Google Patents

Abstract

PURPOSE:To prevent unnecessary wheel spin control from being done as well as to make improvements in travelability so better, by calculating a slip factor in a wheel when a wheel spin is detected at starting and, when this slip factor is less than the specified value, judging that the wheel spin converges. CONSTITUTION:In case of a device which controls at least one side of an accelerator A and a clutch B and checks the torque imposed on a driving wheel C whereby prevents a wheel spin from occurring, a slip factor operational part G calculating a slip factor S from each output signal out of both first and second speed sensors D and F detecting each rotational frequency in the driving wheel C and a driven wheel E is installed in a controller 5. Also there is provided with a wheel spin convergence judging part F which judges that a wheel spin state converges when this slip factor S is less than the setting value. And, when that the wheel spin state tends to converge is judged, wheel spin control is made so as to be prohibited.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a skid control device for a vehicle.

(Prior art) When starting or driving a vehicle, if a driving force that exceeds the friction coefficient (grip force) between the road surface and the tires is applied to the drive wheels, the drive wheels will spin (wheel spin) and the vehicle may not be able to start. , an accident occurs in which the vehicle goes off the track while cornering.

Therefore, as shown in FIG. 5, the rotational speeds of the driving wheels 2a and 2b of the vehicle l are detected by rotation sensors 3a and 3b,
The rotation speed detecting parts 4a and 4b detect a rotation speed of 2 degrees, the comparison part 5 detects a rotation difference (ratio), and when this rotation difference (ratio) exceeds a predetermined value, it is determined that wheel spin has occurred. Then, the controller 6 outputs a "disconnect" signal to the clutch 7 or a "close" signal to the throttle 8 to control the driving force of the drive wheels 2a, thereby preventing the occurrence of wheel spin when the vehicle starts. (See Japanese Unexamined Patent Publication No. 59-202963).

However, in the above-mentioned conventional technology, when the occurrence of wheel spin is detected when starting, the clutch is immediately disengaged.
Alternatively, since the throttle is controlled to close, control is performed even when the wheel spin is naturally converging, so in such a case,
On the contrary, there was a problem in that the driving feeling deteriorated.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and it determines whether or not it is necessary to perform wheel spin control based on the slip rate, and if it is not necessary, performs wheel spin control. The purpose is to improve the driving feeling by preventing this from happening.

(Structure of the Invention) Therefore, the present invention has the following features, as shown in FIG.
In a vehicle in which wheel spin of the tires is prevented by reducing the torque applied to the drive wheels C by controlling at least one of the accelerator A and the clutch B,
A first rotation sensor D detects the rotation of the drive wheel C, a second rotation sensor F detects the rotation of the drive wheel E, and a first rotation sensor D detects the rotation of the drive wheel C. The wheel spin convergence determining section F determines that the wheel spin state has converged when the slip rate is less than or equal to a set value. It is composed of

(Effects of the Invention) According to the present invention, when wheel spin is detected at the time of starting, the slip rate is calculated in the slip rate calculation section, and the wheel spin convergence determination section determines that wheel spin is detected when the slip rate is less than a set value. Since it is determined that the wheel spin has converged, it is possible to determine whether wheel spin control is necessary or not, and when wheel spin is in the direction of convergence, wheel spin control can be prevented. Therefore, the driving feeling will be improved.

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

As shown in FIG. 2, the front wheels (drive wheels) l of the FF vehicle 10
1, 11 and rear wheels (driving wheels) 12, 12 are provided with rotation speed detection sensors 13, 13, 14, 14, 14 for detecting the rotation speed, respectively, and each rotation speed detection sensor 13, 14 is connected to a control device 15. On the other hand, a throttle actuator 16 is connected to the control device 15, and the throttle actuator 16 controls the throttle 18 of the engine 17, and an accelerator sensor 20° is provided to detect the amount of depression of the accelerator pedal 19. , the throttle actuator 16 is controlled in accordance with the detection signal of the sensor 20.

A clutch actuator 21 is connected to the control device 15, and the clutch actuator 21 controls the clutch 23 of the transmission 22. A clutch sensor 25 is also provided to detect the depression position of the clutch pedal 24. The clutch actuator 21 is controlled according to the detection signal.

The control device 15 also includes an accelerator control system control section that outputs a signal for controlling the throttle opening to the throttle actuator 16 in response to a detection signal from the accelerator sensor 20, and a drive force for the drive wheels 11 when wheel spin occurs. but,
A spin control system control unit is provided that calculates the throttle opening to achieve a target value that provides the maximum grip force on the road surface and outputs a signal to the throttle actuator 16 to control the throttle opening. There is.

Furthermore, the control device 15 includes a clutch control system control section that outputs a signal for controlling clutch connection to the clutch actuator 21 in accordance with the detection signal of the clutch sensor 25;
A spin control system control section is provided that outputs a signal for controlling a clutch connection prevention valve to stop connection of the clutch when wheel spin occurs.

On the other hand, the control device 15 includes a rotation speed detection sensor 13 for the drive wheel 11 and a rotation speed detection sensor for the drive wheel I2! A slip rate calculation unit (G
) is provided.

As shown in FIG. 4(a), the slip ratio calculating section (G) stores the relationship between the friction coefficient (μ) and the slip ratio (S) as a map.

In this map, the maximum slip rate at which the maximum grip force μp (friction coefficient) can be obtained is not affected by road surface conditions, etc.
Since it is around 0.3 (30%), the maximum slip rate is 0.
．． It is set to 3.

Further, the control device 15 is provided with a wheel spin convergence determining section (F) that determines that the wheel spin state has converged when the slip rate (S) is less than or equal to a set value.

That is, in the wheel spin convergence determination section (F), as shown in FIG.
From the map in a), the grip force (
μ0) is calculated, μp/μ0 is calculated, and the tire margin (
Find ηS).

Furthermore, as shown in Fig. 4(b), the engine speed (ESP), throttle opening (θ), and engine torque (
The relationship with T) is stored as a map, and from this map, the engine torque (Tc) for the current engine speed and throttle opening is determined, Tp (maximum engine torque)/Tc is calculated, and the drive margin ( Find ηT).

And tire margin (η8) / drive margin (ηT)
When ηS/ηT≦1, that is, when the tire margin (ηS) is larger (positive), it is determined that the wheel spin is heading in the direction of convergence, and wheel spin control is not performed. do not have. Conversely, when the drive margin (four wheels) is larger (negative), it is determined that the wheel spin is in a direction that does not converge (divergence), and wheel spin control is performed.

The operation of the skid control device configured as described above is explained in the third section.
This will be explained with reference to the flowchart shown in the figure.

In step S1, it is determined whether it is the measurement/control timing, and if YES, in step S2, the driving wheels 11. The rotation speed of the drive wheels 12, the accelerator pedal position, the current throttle opening, etc. are measured.

Then, in step S3, vehicle running conditions such as slip rate and wheel spin state are detected, and in step S4 it is determined whether or not wheel spin is occurring.

If the determination in step S4 is No (stopping), the throttle opening corresponding to the accelerator pedal position is calculated in step S5, and the start flag SP is set to "0" in step S6.
” (stopped), it is determined in step S7 whether or not the vehicle is stopped.

If YES is determined in step S7, it is determined in step S8 whether or not the clutch 23 is depressed, and in step S9 it is determined whether or not the clutch is connected.
If it is determined to be ES, the start flag SF is set to "bi" (starting) in step SIO, and control at the time of starting is performed in step Sit.

Then, in step S12, the start flag SF is set to “BI(
If YES, step S
In step S13, it is determined whether the clutch 23 is completely engaged (connected), and in step S14, it is determined whether the vehicle speed has exceeded the idle vehicle speed. If YES, the start flag SF is set to "0" in step S15. ”, and the process proceeds to step S24.

In step S24, the throttle actuator 16 is controlled by the throttle control signal of the accelerator control system that determines the throttle opening degree from the accelerator pedal position, and no spin control is performed.

On the other hand, if it is determined as YES in step S4, then in step S16 the engine speed (ESP) and the throttle opening (
The current engine torque (Tc) is calculated from θ), and in step S17 it is determined whether the maximum engine torque (Tp) is higher than the current rotation.

If No, spin control is not performed.

If YES in step S17, the maximum engine torque (Tp) at the current throttle opening is determined in step S18.
) is calculated, and the driving margin (ηT) is determined in step S19. (ηT=Tp/TO).

Furthermore, in step S20, the grip force (μ0) for the current slip rate is determined, and the tire margin (ηS) is determined (ηS=μp/μ0).

Then, in step S21, the tire margin (ηS)/drive margin (ηT) is calculated, and when it is "positive", it is determined that the wheel spin is heading in the direction of convergence, and no spin control is performed.

Conversely, when it is "negative", it is determined that the wheel spin is heading in the direction of divergence, and in step S22, the control state quantity (
Control target value) is calculated, and in step S23, the throttle opening degree is calculated so as to approach the target value, and in step S12. S13. S14° After passing through S15, the process proceeds to step S24.

In step S24, the current throttle opening degree and the target throttle opening degree are compared, a throttle control signal that achieves the target throttle opening degree is generated, and the throttle actuator 16 is controlled by the throttle control signal. As a result, the driving force of the driving wheels 11 decreases according to the running state of the vehicle, and wheel spin is stopped.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, FIG. 2 is a block diagram of a skid control device according to the present invention, FIG. 3 is a flowchart, and FIG. 4(a) is a graph showing the relationship between slip rate and friction coefficient. FIG. 4(b) is a graph showing the relationship between engine speed and engine torque, and FIG. 5 is a configuration diagram of a conventional skid control device. 10...FF vehicle, 11(C)...Front wheel (drive wheel), 12(E)...Rear wheel (drive wheel), 13(D), 14(F)...Rotation speed detection sensor , 15
...Control device, 18(A)...Throttle, 2
3(B)...Clutch, G...Slip rate calculation unit, F...Wheel spin convergence determination unit.

Claims (1)

[Claims] (1) In a vehicle that prevents wheel spin of the tires by reducing the torque applied to the drive wheels by controlling at least one of the accelerator and the clutch, a first rotation sensor that detects the rotation of the drive wheels; a second rotation sensor that detects the rotation of the driving wheel; a slip rate calculation section that calculates the slip rate from the detection signals of the first and second rotation sensors; A skid control device for a vehicle, comprising: a wheel spin convergence determination section that determines wheel spin convergence.