JPS62137258A - Driving force control device for self-running vehicle - Google Patents

Abstract

PURPOSE:To prevent an excessive slip from occurring alternately to right and left wheels and to produce a high-efficient driving force, by a method wherein, the rotation speed of a driving wheel exceeds a speed threshold and a difference between right and left rotation is below a given value, both the right and the left driving wheels perform the same brake operation. CONSTITUTION:The rotation speeds of driving and driven wheels are calculated by rotation detecting means 14 and 15, and a speed threshold is set by a speed threshold setting means 16 of a microcomputer 11. In which case, when the rotation speed of the driving wheel exceeds a speed threshold and is below a given speed at which the more the rotation speed of the driven wheel is increased the more a difference between right and left rotation speeds is increased, a control instruction is outputted from a control part 19 to a brake control device B. The right and the left driving wheel are forced to perform the same brake operation and are controlled to a rotation speed near a desired value to produce a well suitable driving force. This constitution enable prevention of the occurrence of a seesaw-shaped fluctuation in a rotation speed and the occurrence of an excessive slip in a low speed area.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a driving force control device for a self-propelled vehicle such as an automobile, and the present invention relates to a driving force control device for a self-propelled vehicle such as an automobile, and the present invention relates to a driving force control device for a self-propelled vehicle such as an automobile. It has been devised to obtain power, and can be applied to four-wheeled vehicles equipped with a differential mechanism similar to automobiles and tractors.

[Conventional technology]

As a driving force control device, the slip rate of the driving wheels.

Alternatively, the running characteristic value such as the rotational speed is compared with a threshold value set based on the rotational speed of the driven wheel, and the running characteristic value of the driving wheel is maintained in a constant relationship with this threshold value. A control device is known that controls the braking force acting on a single-body vehicle in such a manner as to

[Problem that the invention seeks to solve]

Conventional control devices are configured to control the braking force for each left and right drive wheel, so there are cases where the left and right drive wheels are braked and the other side is not braked. When the difference in rotational speed is small, for example, the drive wheel on the negative side suddenly becomes slower due to the brake, and conversely, the drive wheel on the other side suddenly becomes faster due to the differential action, so at the next point, the drive wheel on the other side suddenly becomes slower due to the brake. The brakes are applied to the drive wheels on the side, causing the wheels to suddenly slow down, and then the drive wheels on the left and right sides are driven to high speeds again, and the brakes are applied. Therefore, there is a problem in that the excessive slip condition continues l- and the desired driving force cannot be obtained.

[Means for solving problems]

This invention proposes a driving force control device devised to prevent the left and right driving wheels from slipping excessively alternately and to obtain efficient driving force. Rotational speed detection means (+41
, fl5), a brake control device (Bl) that applies a braking force corresponding to the brake pressure to the wheels, and a speed threshold setting that sets a speed threshold (vl) that is the control reference speed of the drive wheel (1). means 161 and a brake control device (giving a BIK command) to control the rotational speed of the drive wheel (1) based on the difference between the rotational speed of the drive wheel (1) with respect to a speed threshold (Vl) K; In the driving force control device having the control unit 09 configured as shown in FIG. Below a predetermined speed (VO), the left and right drive wheels (1).

The control unit a9 is configured so that the same braking operation is performed in both cases (1) and this predetermined speed (vO) increases in accordance with the rotational speed (VT) of the driven wheel (2). This is a driving force control device for a self-propelled vehicle characterized by the following configuration.

[Effect]

When the rotational speed of either the left or right drive wheel (1) exceeds the speed threshold (vl), the difference in rotational speed between the left and right wheels reaches the predetermined speed (
vo) In the following, the same braking operation is performed on both the left and right drive wheels (1), (1), so both the left and right wheels are controlled to a rotational speed close to the desired, and a suitable driving force is obtained. In the low speed range, it is possible to prevent seesaw-like fluctuations in rotational speed and excessive slip caused by applying independent brakes to the left and right drive wheels (+1) and (11), respectively, and This predetermined speed (vo) increases as the rotational speed (VT) of the driven wheel (2) increases, so in a non-low speed range where there is little risk of the seesaw-like fluctuation, one drive wheel (1) (1) Rotational speed control is performed for each of (1), and each driving vehicle @(1),
fl) both exhibit suitable driving force.

〔Example〕

Next, one embodiment of this invention will be explained based on the drawings. Second
Figure 1 shows a circuit diagram of a driving force control device applied to an automobile as an example of a self-propelled vehicle, and Figure @1 shows its block diagram. For example, the front left and right drive wheels (11, (11
and the rear driven wheel (2+, (2)).

The brake force is applied by the action of the brake control device + Bl, and the brake control device (Bl
is the rotor (3) of each of the above wheels (1) and (2).
When the brake pedal (5) is depressed, a mask cylinder (6) is inserted into the brake cylinder (4), which is provided corresponding to
) Pressure oil cuff flow Portional valve (■) Togate pulp (GV) The opening operation of the hold valve (HV), decay valve (DV), which is supplied through fl or controlled as follows: A pump with a structure in which the brake piston (8) presses the brake shoe against the rotor (3) as pressurized oil is supplied to the pump by the closing operation is used. Here, a proportional valve (PV) is used.
is a normal brake pressure control valve that has the function of changing the ratio of the amount of pressure oil supplied to each of the above wheels (11, (2+), and the gate valve (σ) is controlled by its opening or closing operation. , the pressure oil of the mask cylinder (6) can be supplied to the brake cylinder (4), or the supply can be cut off.The hold valve (HV') controls the pressure of the pump (power Supply oil to the brake cylinder (4).

It also has a function to cut off the supply, and has a decay valve (DV) function.
The pressure oil in the brake cylinder' (4) is discharged or the discharge is shut off by its opening or closing operation.

Further, in the illustrated throttle device, a fuel control valve section is opened according to the operation amount of an accelerator operation member (9) such as an accelerator pedal, and the fuel control valve section is opened in accordance with the operation amount of an accelerator operation member (9) such as an accelerator pedal. The structure is such that fuel is supplied to the

Next, an example of the control means will be explained.

The rotational speed of the left and right driving wheels (1) (11 (11) is measured by the rotation sensor (S+), and the left and right driven wheels (2)
, (2) is measured by a rotation sensor (S2), respectively, and the rotation speed calculation unit α2 (131) is configured using a microcomputer aυ, for example, and the left and right of the drive wheel (1) is Rotational speed of each side ('Voa),
(Vob) and the rotational speed of the driven wheel (2) (v'T)
and rotational speed detection means α4) for detecting the respective rotational speeds,
The speed threshold (V
the speed threshold based on the rotational speed (Vt) above,
The value is set by the value setting means the.

In addition, the slip rate calculation means αη calculates the slip rate of the left and right drive wheels (1), (11 (81 is the target 1 rotation speed VDa), (Vbb) and the rotation speed α0, and the drive wheels (Slip ratio 1-threshold value setting means for setting the slip ratio threshold value (So) which is the control reference slip ratio of No. 11 is provided, and is provided in the microcomputer 113 to control the brake control device t(B). Control @ part (1'1 is the rotational speed q (Vna) in the low speed range,
What is the magnitude of (VDb) relative to the speed threshold (■ri)?
b) Determine how much of a difference there is and install the gate valve (GV).
), hold valve θ′).

In order to command the opening/closing control of each decay valve (DV), the slip rate (
81 is determined relative to the slip ratio threshold value (Su), and commands are given to control the opening and closing of each of the valves.

That is, the drive wheels on each side are at the top of FIG.

The course of fluctuations in the rotational speed (vDa) and (VDb) of (summer), the brake pressure (Pa) in the drive wheel (1) on each side, (11 brake cylinders (4)),
(Pb) (The driving wheel (1) at the rotational speed (Vna) corresponds to (Pa), and the driving wheel (1) at (vDb) corresponds to (Pb)). ) on the lower part of Figure 3, the driving wheels (1) on each side, (
As shown in the example of the progress of the opening/closing state of the gate valve (Gv)% in 1), when a self-propelled vehicle is started, the gate valve (Gv)% is opened and closed.
GV) is opened, and both the hold valve (HV) and 7' Ikei Pulp (DV) are not closed, and when you step on the accelerator at one point (An), the throttle opening (the sword rises 1., the drive wheel (1) and the driven wheel (2) gradually increase in speed, and in the rotational speed control illustrated below, when the speed threshold (vl) is exceeded, the brake is applied and the speed of the driving wheel (1) is increased. This brake pressure is increased during acceleration, and reduced during deceleration.
Moreover, when the rotational speed difference between the left and right drive wheels (1), (1) is around a predetermined speed (vO), the same brake pressure increase or decrease is applied to each drive wheel (1) at the same time. , when the rotational speed is less than a predetermined speed (vO), the brake pressure is increased or decreased only on the high-speed drive wheel (1). Left and right, which occurs in the normal control that is done! ! ! The seesaw-like speed fluctuations of the driving wheels (11, (11) and the resulting excessive slippage are prevented by simultaneous braking when the speed difference is small.

That is, among the rotational speeds of the left and right drive wheels (11, (11), the high rotational speed is (VM) - the lower rotational speed is (VN)
), then when 1 revolution speed 111[(VM) reaches speed 1-threshold (V+) (time point person), throttle opening (
℃ is held at the opening degree at that time by the action of the throttle valve (SV), and at the same time the brake action is started.The difference between the rotational speed (vM) and (VN) - f
i'0 When (VM) - (VN) is less than the predetermined speed (vo), the gate valve (GV) Y of the high-speed drive wheel (Ml) and the low-speed drive wheel INI is closed and the hold valve (HV ), the brake pressure (Pa),
(Pb) will increase, and if -(VM) -(
When VN) exceeds a predetermined speed (vo), the gate valve (GV) Y of only the high-speed drive wheel tM) is closed and the hold valve (Hv) ff is opened to apply the brakes.

If the rotational speed α or (VN) of the drive wheel [M) or (N) continues to increase even after a predetermined time (tl) from the time point (tl), or the throttle opening ('
If D or the engine speed is above the set value, close the throttle valve (SV) for 2 seconds and lower the throttle opening (lower the sword) by α, then - this throttle opening (
T'lf? -Hold. - The rotational speed (VN) of the drive wheel (Nl) on the low speed side also reaches the speed 1-1 threshold (Vl
) - (V
Since the difference between M) - (■) is more than 0, the hold valve (HV)y of only the low-speed drive vehicle @ (N) is closed, the decay valve (DV) is opened, and the brake pressure (Ph) is increased. If the pressure is reduced or VM) - (VN) < vO, both driving wheels (MI I (Brake pressure (Pa) of Nl) (Pb
) are controlled to hold both at the same time, but in addition to this, in place of the above-mentioned pressure reduction operation, hold percentage control is performed to slightly delay the opening operation of the decay valve (DV) from the closing operation of the hold pulp (HV). You can go)
, then when the rotation speed (VM) of the high-speed drive wheel IM) also reaches its maximum value (time B), the hold valve (HV) i of this drive wheel tM+ closes and the decay valve (DV)'
? It opens and reduces the pressure to the brake pressure (Pa)', and then the drive wheel on the low speed side (AC at C when the rotational speed (VN) of Nl falls below the speed threshold (Vl) fL' and becomes the minimum value)
, hold valve (HV), decapal 7' (DY)
'& both are closed to hold the brake pressure (Pb), and the drive wheel (vDb) becomes high speed first, and the continuous 1. threshold (
vl) (time d), this drive wheel (Vo
The speed difference between the rotational speed (VN) of the drive wheel (Voa) that has become lower speed with respect to the rotational speed (■τ) of b), that is, -(■
)-(VN) exceeds the predetermined speed RJ-(vo), the driving wheel (VDh) (7"1 hold valve (HV
) and close the decay valve (DV) to increase the brake pressure (Pb).
N) is the driving wheel (VOID), ('1
ba) Common IC-Ho71z)'Pulp (HV)'kt
;il Decay valve (DV) closed) Drive wheel (V
At the moment when the rotational speed (VN) of Da) has reached its minimum value (time C), the hold valve (HV) and the decay valve (Dv
)'ff are closed together.

Then, the driving wheels (to)) and (to)) increase their speed until the rotation speeds (VM) and (VN) reach the speed threshold (Vt) and reach the following respective maximum values. 1''!, the hold valve (HV) and the hold valve (, DV) are maintained in the above-mentioned control state at this speed threshold (Vl) (times D-+E, G).
−+H1 and time points d−+e, g−+h), and
Times IFtii! [During the deceleration state from one maximum value of (VM) and (VN) to the next minimum value, the hold valve (HV
) closed, the decay valve will be kept open (times B4C, E-+F', H-, I and time k) -+(-
e-+f, h-+i).

Then, when the rotational speed (v'r) of the driven vehicle @ (2) increases to a predetermined speed (v2) (time Z), the speed threshold (Vl) is set to increase to v3, and from then on, as described above, Speed (-critical value (Vl) and rotational speed (Vba), (to))
The rotational speed control based on the difference between the drive wheels (1) and
, (Slip rate control is performed based on the difference between the slip rate (Sl) and the slip rate threshold (茄) of 11. As an example of this slip rate control, the slip rate (81 is the slip rate threshold) When the value (Su) is below the value (Su)?, the hold valve (Hv) is closed and the decay valve (f)'a? is opened, thereby reducing the brake pressure, and the slip rate tS+ becomes the slip rate threshold value. (8 ports), the brake pressure is increased by opening the hold valve () (v) and closing the decay valve (DV), and the slip ratio (81 ports) is increased.
When the brake pressure matches the slip ratio threshold value (S1+), the brake pressure is held by closing both the hold valve (HV) and the decay valve (DV).

Control part 0! It is configured such that a command is given from J to brake control section ff (Bl).

Also, before the end point Z of the rotational speed control, the decay valve (1) V) is opened to discharge pressure oil from the brake cylinder (4), and the gate pulp (G
V) is controlled to open.

When the hold valve (H￥) and decay valve (DV) are both closed (time point ■), a certain period of time of 13 seconds or more has elapsed, and the decay valve (DV) is opened and closed for 14 seconds. The control unit CIIK gradually discharges the pressure oil and at the same time gradually increases the throttle opening and then opens the gate pulp (JV). (2) in proportion to the rotational speed (VT), for example.

Alternatively, the control unit a9 is configured to increase in steps.

Therefore, left and right drive wheels (1), 7 to (1)
``In a non-low speed range where there is little risk of the rotational speed repeating seesaw-like changes tfJ due to the V-key action, since the predetermined speed (vO) is large, the rotational speed control is performed for each drive wheel (11, (11). In the rotational speed control described above, the present invention can also be applied to a system in which brake pressure is controlled using two threshold values for high speed and low speed as the speed threshold value (V+). Also, although it may be the case that there is no slip rate control, when performing slip rate control, for example, two slip rates may be set as thresholds, and either control may be performed according to the embodiment described above. Besides, speed control and slip rate control using various methods can be used.

Further, a generator-type rotation sensor may be used as the one-rotation speed detection means αz, 09, and the brake control unit f (Bl may be an air brake).

〔Effect of the invention〕

The driving force control device for a self-propelled vehicle according to the present invention is configured as described above, and has the following configuration:
When the rotational speed of the left and right wheels exceeds the speed threshold (V), if the rotational speed difference between the left and right wheels is less than the predetermined speed (vO), the left and right drive wheels:
Since the same braking action is performed on both wheels (1) and (11), the rotational speed of both the left and right wheels is controlled close to desired and a suitable driving force can be obtained. By applying independent brakes to the drive and wheels (11, (1), it is possible to prevent seesaw-like fluctuations in rotational speed and the occurrence of excessive slip due to this, and this predetermined speed (vO) (2) becomes a large value as the rotational speed (Vr) increases, so in the non-low speed range where there is little risk of the seesaw-like fluctuation, each of the left and right drive wheels (1) (1) (1) Rotation speed control is performed at the same time, and both of the top drive wheels (11 and (1)) are able to exert suitable driving force, resulting in rapid acceleration control with little slippage. be.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which FIG. 1 is a block diagram of a control circuit, FIG. 2 is a circuit diagram of a control device, and FIG. 3 is a control characteristic diagram. Description of symbols (1)... Drive wheel (2)... Servant blood wheel (141, 151... Rotation speed detection means (16)
1... Speed threshold value setting means 0! l...
・Control unit (Bl... Brake control device (VO)... Predetermined speed (VL)... Speed threshold (VT)... Rotational speed j −=−−−”−N

Claims (1)

[Claims] A rotational speed detection means that detects the rotational speed of each of the driving wheels and the driven wheels, a brake control device that applies a braking force corresponding to the brake pressure to the wheels, and a speed threshold that is a control reference speed of the driving wheels is set. a speed threshold setting means for setting a speed threshold; and a control unit configured to give a command to a braking device to control the rotational speed of the drive wheel based on the difference between the rotational speed of the drive wheel and the speed threshold. In a driving force control device having a drive wheel, when the rotational speed of either the left or right drive wheel exceeds the speed threshold, the same braking operation is applied to both the left and right drive wheels if the rotational speed difference between the left and right is less than a predetermined speed. A driving force control device for a self-propelled vehicle, characterized in that the control section is configured so that the predetermined speed is increased according to the rotational speed of the driven wheel.