JP2513008B2 - Vehicle acceleration slip control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an acceleration slip control device for a vehicle, which suppresses acceleration slips of driving wheels generated during vehicle acceleration.

[Prior Art] Conventionally, as one of the acceleration slip control devices for a vehicle, when an acceleration slip occurs in the drive wheels, the throttle valve is opened / closed to control the output torque of the internal combustion engine to suppress the acceleration slip. There is known a device that does.

In addition, in such opening / closing control of the throttle valve, the response delay of the drive system until the throttle valve is driven in the closing direction to be controlled to the target opening and the response of the intake system until the intake amount becomes a value according to the throttle opening. Due to the delay, it may take time until the output torque of the internal combustion engine is suppressed after the start of control, and it may not be possible to quickly suppress the rotation of the drive wheels immediately after the occurrence of the acceleration slip. Immediately after the occurrence of the acceleration slip, it is considered that the output torque of the internal combustion engine is promptly suppressed by the fuel cut control or the ignition timing retard control.

[Problems to be Solved by the Invention] However, when the output torque of the internal combustion engine is suppressed by the fuel cut control or the ignition timing control immediately after the occurrence of the acceleration slip, the output torque control is conventionally performed after the acceleration slip has occurred. Since it was executed until the rotation speed of the internal combustion engine becomes less than the predetermined rotation speed, the output torque of the internal combustion engine is suppressed too much on the road surface with a large friction coefficient (hereinafter referred to as high μ road), and the acceleration of the vehicle is poor. On the contrary, on the contrary, there is a problem that the output torque of the internal combustion engine cannot be sufficiently suppressed on a road surface having a small friction coefficient (hereinafter referred to as a low μ road) and the slip continues for a long time.

In other words, on a high μ road, the driving wheel receives a large drag force from the road surface when an acceleration slip occurs, so it is possible to suppress the acceleration slip even if the rotation speed of the internal combustion engine is relatively high.
On low-μ roads, the drag force that the drive wheels receive from the road surface when acceleration slip occurs is small, so acceleration slip may not be suppressed unless the rotational speed of the internal combustion engine is sufficiently reduced. If the control and retard control of the ignition timing are uniformly controlled by the rotational speed of the internal combustion engine after the occurrence of the acceleration slip, the output torque between the internal combustion engines immediately after the occurrence of the acceleration slip is the friction coefficient of the road surface (hereinafter referred to as road surface μ). ), It cannot be optimally controlled.

Therefore, the present invention promptly suppresses the output torque of the internal combustion engine by the fuel cut control and the ignition timing retard control immediately after the occurrence of the acceleration slip as described above, and the device that performs the subsequent acceleration slip control by the throttle control,
The purpose was to enable the output torque control immediately after the occurrence of the acceleration slip to be optimally executed according to the road surface μ.

[Means for Solving the Problems] That is, the present invention made to achieve the above object is
As illustrated in the figure, a driving wheel speed detecting means M1 for detecting the driving wheel speed, and an acceleration slip detecting means M3 for detecting an acceleration slip of the driving wheel M2 generated during vehicle acceleration with the driving wheel speed as one parameter. When the acceleration slip is detected by the acceleration slip detection means M3, the intake passage M5 of the internal combustion engine M4 that drives the drive wheel M2 until the acceleration slip does not occur on the drive wheel M2.
Open and close the throttle valve M6 provided in the internal combustion engine
Throttle opening control means M7 for controlling the output torque of M4
In a vehicle acceleration slip control device comprising: a rotational acceleration detection means M8 for detecting the rotational acceleration of the internal combustion engine M4 or the drive wheels M2; and an acceleration slip is detected by the acceleration slip detection means M3 to open the throttle. When the degree control means M7 starts the opening / closing control of the throttle valve M6, then the rotational acceleration of the internal combustion engine M4 or the drive wheels M2 detected by the rotational acceleration detection means M8 is temporarily reduced to a predetermined value or less. The gist is an acceleration slip control device for a vehicle, which is provided with an engine output control means M9 for controlling the ignition timing or the fuel supply amount to suppress the output torque of the internal combustion engine M5 during the period.

[Operation] In the acceleration slip control device of the present invention configured as described above, when the acceleration slip detection means M3 detects the acceleration slip of the drive wheel M2, the throttle opening control means M7 is activated to operate the internal combustion engine M4. Open and close the throttle valve M6,
The output torque of the internal combustion engine M4 is suppressed. When the operation of the throttle opening control means M7 starts, the engine output suppressing means
M9 operates, until the rotational acceleration of the internal combustion engine M4 or the drive wheels M2 detected by the rotational acceleration detection means M8 once falls below a predetermined value, the ignition timing or the fuel supply amount is controlled to control the internal combustion engine M4. Suppress output torque.

Therefore, in the present invention, immediately after the occurrence of the acceleration slip of the drive wheel M2, the output torque of the internal combustion engine M4 is promptly suppressed by the ignition timing control or the fuel supply amount control, and then the optimal acceleration performance is controlled by the opening / closing control of the throttle valve M6. The output torque of the internal combustion engine M4 is controlled so that Further, the engine output suppressing means M9 is
Since it operates until the rotational acceleration of the internal combustion engine M4 or the drive wheel M2 once falls below a predetermined value, the engine output suppressing means M9
It becomes possible to perform the output torque control by the method according to the road surface μ.

That is, on the high μ road, the rotation speed of the drive wheel M2 starts to rapidly decrease due to the output torque control, and conversely, on the low μ road, the rotation speed of the drive wheel M2 does not start to decrease unless the output torque control is sufficiently executed. Until the rotational acceleration of the internal combustion engine M4 or the drive wheels M2 once falls below a predetermined value, the engine output suppressing means M9
By executing the output torque control by, the output torque control can be executed for a time corresponding to the road surface μ,
The slip state at the time of stopping the output torque control by the engine output suppressing means M9 can always be controlled to the optimum state.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

First, FIG. 2 is a schematic configuration diagram showing the overall configuration of an acceleration slip control device of an embodiment in which the present invention is applied to a front engine / rear drive (FR) type vehicle in which an internal combustion engine 2 is used as a power source.

As shown in the figure, in the intake passage 4 of the internal combustion engine 2, a surge tank 4a for suppressing pulsation of intake air is formed, and upstream thereof, a main throttle valve 8 which is opened / closed in conjunction with an accelerator pedal 6 and a drive motor. A sub-throttle valve 12 opened and closed by 10 is provided in parallel. The main throttle valve 8 and the sub-throttle valve 12 are respectively provided with a main throttle valve opening sensor 14 and a sub-throttle opening sensor 16 which detect the opening thereof, and the detection signals from these sensors are acceleration slips. It is input to the control circuit 20.

Acceleration slip control circuit 20 is the left and right drive wheels (rear wheels) 22R
The drive motor 10 detects the acceleration slip occurring in L and 22RR.
The output torque of the internal combustion engine 2 is suppressed by opening and closing the sub-throttle valve 12 via the valve, and the output torque control delay due to the opening and closing control of the sub-throttle valve 12 immediately after the acceleration slip detection is compensated. The fuel injection valve 24 according to the operating state of the internal combustion engine 2.
Well-known internal combustion engine control circuit 26 for controlling the fuel injection amount from the
A fuel cut (hereinafter, also referred to as F / C) command signal is temporarily output to the fuel injection valve 24 to execute the F / C control for stopping the fuel injection from the fuel injection valve 24. Internal combustion engine control circuit 2
6 is configured to stop the fuel injection from the fuel injection valve 24 while the F / C command signal from the acceleration slip control circuit 20 is being input, and the output torque of the internal combustion engine 2 is controlled by this F / C control. Will decrease rapidly.

Further, the acceleration slip control circuit 20 is supplied with detection signals from various sensors that detect the traveling state of the vehicle in order to perform such acceleration slip control. That is, the acceleration slip control device includes a rotation speed sensor 30 for detecting the rotation speed of the crankshaft 2a of the internal combustion engine 2 and left and right idler wheels (front wheels) 22FL, 22F as sensors for detecting the running state of the vehicle.
Left and right idler wheel speed sensors 3 to detect the rotation speed of R
In order to detect the average rotational speed (drive wheel speed) of the 2FL, 32FR and the left and right drive wheels 22RL, 22RR, the rotation of the crankshaft 2a is transferred to the left and right drive wheels 22RL, 22RR via the propeller shaft 34 and the differential gear 36. A drive wheel speed sensor 40 provided on the output shaft of the transmission 38 for transmission is provided, and detection signals from these sensors are input to the acceleration slip control circuit 20.

Next, the acceleration slip control circuit 20, as shown in FIG.
The CPU 20a, the ROM 20b, the RAM 20c, the backup RAM 20d, the input / output port 20e, and the common bus 20f that connects these units are mainly configured as a logical operation circuit. The detection signal from the sensor 16 is direct and the rotation speed sensor 3
0, the detection signals from the left and right driven wheel speed sensors 32FL and 32FR and the driving wheel speed sensor 40 are indirectly input to the input / output port 20e via the waveform shaping circuit 20g. I / O port 2
At 0e, the F / C command signal is output to the drive circuit 20h for driving the drive motor 10 of the sub-throttle valve 12 to control the sub-throttle valve 12 to the target opening θS0, and the internal combustion engine control circuit 26. An F / C command signal output circuit 20i for executing F / C control is connected, and the opening / closing control of the sub-throttle valve 12 and the F / C of the internal combustion engine 2 are performed via these units.
It is made possible to execute control.

Hereinafter, the acceleration slip control circuit configured as described above
The acceleration slip control executed in 20 will be described in detail with reference to the flowchart shown in FIG.

This processing is performed for a predetermined time (several mse) after the start of the internal combustion engine 2.
c. ) Every time the processing is started, first, step 100 is executed to check whether the main throttle valve 8 is not in the fully closed state at present and the execution condition of the acceleration slip control is satisfied. to decide. If the execution condition of the acceleration slip control is not satisfied, the routine proceeds to step 110, where the counter CEND for the acceleration slip control signal and the flags FS and FCUT are reset and the drive circuit 2
The maximum opening degree θSmax of the sub-throttle valve 12 is set as the target opening degree (hereinafter referred to as the target sub-throttle opening degree) θS0 of the sub-throttle valve 12 whose drive is controlled by 0h. The initialization process is executed and the process is temporarily terminated. .

On the other hand, when it is determined in step 100 that the conditions for executing the acceleration slip control are satisfied, the process proceeds to the following step 120, based on the detection signals from the left and right driven wheel speed sensors 32FL and 32FR, the left and right driven wheels 22FL, The average rotational speed VF of 22FR is calculated as the vehicle body speed, and the process proceeds to step 130. In step 130, the target rotation speeds (hereinafter, referred to as target drive wheel speeds) VS of the drive wheels 22RL and 22RR are calculated by multiplying the calculated vehicle body speed VF by a preset target slip ratio (for example, 1.2). Then, in the following 140, the left and right drive wheels 22 obtained based on the detection signal from the drive wheel speed sensor 40.
RL, 22RR average rotation speed (hereinafter referred to as drive wheel speed) VR
And the deviation ΔV between the target drive wheel speed VS obtained in step 130
(= VR-VS) is calculated as the slip amount of the drive wheel.

Next, at step 150, it is judged whether or not the control execution flag FS set at the start of execution of the acceleration slip control in the process described later is in the set state, that is, whether or not the acceleration slip control is currently being executed, and the control is executed. If the execution flag FS is in the reset state and the acceleration slip control is not executed, the routine proceeds to step 160. In step 160, it is determined whether or not an acceleration slip has occurred in the drive wheels 22RL, 22RR depending on whether the slip amount ΔV obtained in step 140 is a positive value. If ΔV ≦ 0, it is determined that no acceleration slip has occurred on the drive wheels, the process proceeds to step 110, the above-described initialization process is executed, and then the process is temporarily terminated.

On the other hand, if ΔV> 0, it is determined that an acceleration slip has occurred in the drive wheels 22RL, 22RR, the process proceeds to the following step 170, the control execution flag FS is set, and the following step 180
Move to In step 180, the rotational speed NE of the internal combustion engine 2 is obtained based on the detection signal from the rotational speed sensor 30, and the target sub-throttle opening degree θS0 is calculated based on this rotational speed NE using a preset map. Then, in the following step 190, an output command of the F / C command signal is issued to the F / C command signal output circuit 20i, the F / C control execution flag FCUT indicating that is set, and the process ends.

Next, in step 150, if the control execution flag FS is in the set state and it is determined that the acceleration slip control is currently being executed, the process proceeds to step 200, and the F / C control execution flag FCUT is in the reset state. Or not, that is, whether or not the F / C command signal is currently being output from the F / C command signal output circuit 20i and normal fuel supply to the internal combustion engine 2 is being performed. Then, in step 200, the F / C execution flag FC
When it is determined that the UT is in the set state and the F / C control is currently being executed, the routine proceeds to step 210, where the rotational speed NE of the internal combustion engine 2 is based on the detection signal from the rotational speed sensor 30.
Then, a deviation ΔNE (= NE-NEn-1) between this value NE and the rotation speed NEn-1 obtained when the relevant process was executed last time is calculated as the rotation acceleration of the internal combustion engine 2.

The deviation ΔNE becomes the rotational acceleration of the internal combustion engine 2 because the processing is executed every predetermined time, and the step 210 corresponds to the rotational acceleration detecting means M8.

Next, at step 220, it is judged if the calculated rotational acceleration ΔNE of the internal combustion engine 2 is less than or equal to a predetermined value K1. If ΔNE ≦ K1, then in step 230, after stopping the output of the F / C command signal from the F / C command signal output circuit 20i and resetting the F / C control execution flag FCUT, the process proceeds to step 240,
If ΔNE> K1, the process directly proceeds to step 240.

In step 240, the slip amount Δ found in step 140
The opening / closing control amount ΔθS of the sub-throttle valve 12 is calculated using the following equation (1) ΔθS = β1 · ΔV + β2 · ΔV (1) using V and its differential value ΔV as parameters. By subtracting this value ΔθS from the target sub-throttle opening θS0 set when this process is executed, the target sub-throttle valve θS0
Is updated and the process proceeds to step 260.

Next, at step 260, it is judged if the updated target sub-throttle opening θS0 exceeds the main throttle opening θM. If θS0> θM, the next step 270
The counter to measure the state of θS0> θM
CEND is incremented, and the process proceeds to step 280. Conversely, if θS0 ≦ θM, the process proceeds to step 290, the counter CEND is reset, and the process is temporarily terminated. Also in step 280. The value of the above counter CEND is the predetermined value K2
Is exceeded, that is, whether the condition of θS0> θM has passed for a predetermined time or longer, and if CEND ≦ K2, the process is terminated as it is, otherwise, the drive wheels 22RL, 2 are no longer used.
Judging that no acceleration slip will occur in 2RR,
After the initialization process is executed in step 110, the process is temporarily terminated.

In the acceleration slip control device of the present embodiment configured as described above and executing the acceleration slip control, as shown in FIG. 5, first, at time t1, the drive wheel speed VR exceeds the target drive wheel speed VS, and the acceleration slip control is performed. When is detected, opening / closing control and F / C control of the sub-throttle valve 12 are started. Then, the output torque of the internal combustion engine 2 starts to decrease rapidly by the F / C control and becomes a large value due to the acceleration.
The rotational acceleration ΔNE of starts to decrease. When the rotational acceleration ΔNE becomes equal to or less than the predetermined value K2 at time t2, the F / C control is stopped.

The output torque of the internal combustion engine 2 increases again due to the stop of the F / C control, and the rotation speed NE starts to increase, but this time, because the output torque of the internal combustion engine 2 is suppressed by the opening / closing control of the sub-throttle valve 12, The rotation speed NE starts to decrease again. Then, thereafter, by controlling the opening / closing of the sub-throttle valve 12, the drive wheel speed VR becomes the target drive wheel speed VS and is controlled so that optimum acceleration is obtained.

As described above, in this embodiment, immediately after the occurrence of the acceleration slip,
Since the output torque of the internal combustion engine 2 is suppressed by the F / C control, and then the slip control of the drive wheels is executed by the opening / closing control of the throttle valve, the rotational speed NE of the internal combustion engine 2 immediately after the acceleration slip occurs. It is possible to prevent an increase in size and quickly suppress acceleration slip. Further, since the F / C control is executed until the rotational acceleration ΔNE of the internal combustion engine 2 becomes equal to or less than the predetermined value K2 after the occurrence of the acceleration slip, the F / C control is executed according to the road surface μ. Therefore, the output torque of the internal combustion engine 2 can be suppressed according to the road surface μ. That is, there is no possibility that the output torque of the internal combustion engine 2 is excessively suppressed on the high μ road as in the conventional case or the output torque of the internal combustion engine 2 cannot be sufficiently suppressed on the low μ road on the contrary. It is possible to optimally control the torque according to the road surface μ.

Here, in the above embodiment, the initial value of the target sub-throttle opening θS0 at the start of the acceleration slip control is set by the rotational speed NE of the internal combustion engine 2, and the control amount thereafter is the slip amount ΔV.
However, in this case, the output torque of the internal combustion engine 2 cannot be sufficiently suppressed by the opening / closing control of the sub-throttle valve 12 after the completion of the F / C control on the low μ road, and the dotted line in FIG. As shown in, it is conceivable that the drive wheel speed VR after the end of the F / C control becomes higher than that at the start of the control. Therefore, in order to perform good acceleration slip control after the end of F / C control, as shown in FIG. 7, the elapsed time from the start time t11 to the end time t21 of F / C control is measured, and the road surface is measured from the time measurement result. It is also possible to determine μ and set the control initial value of the sub-throttle valve 12 thereafter according to the road surface μ.

That is, for example, as shown in FIG. 6, the target sub-throttle opening degree θS0 immediately after the detection of the acceleration slip and the control amount ΔθS until the F / C control is completed are the values for the high μ roads in step 180 ′ and step 240 ′, respectively. The F / C control execution time is measured by counting up the counter CFC in step 215 from the start of the F / C control to the end of the calculation, using the map and the calculation formula (1). After the C control is completed, the value of the counter CFC is set to the predetermined value K3 in step 300.
Whether the traveling road surface is a low μ road or a high μ road is determined depending on whether or not the above is true. If CFC ≧ K3 and the traveling road surface is a low μ road, step 310
Target sub-throttle opening θ
Reset S0 to a value smaller than the high μ road, and in step 320 set the proportional constants β1 and β2 of the calculation formula (1) for calculating the control amount to the values for the low μ road set to a value smaller than the high μ road. It should be changed.

If the opening / closing control of the sub-throttle valve after the completion of the F / C control is executed according to the road surface μ in this way, as shown by the solid line in FIG. 7, the drive wheel speed VR is changed to the target drive wheel speed VS. It is possible to quickly converge.

Incidentally, in FIG. 6, the same processes as those in the above-mentioned embodiment are designated by the same reference numerals, and therefore detailed description thereof will be omitted.
Further, as described above, the road surface μ can be determined from the execution time of the F / C control because the F / C control is executed according to the road surface μ and the execution time (counter CFC) is as shown in FIG. This is because it changes according to the road surface μ. Further, the target sub-throttle opening θS0 at the time of executing the F / C control is set by using the map for high μ road and the calculation formula (1) is controlled by using the map and calculation formula for low μ road. This prevents the sub-throttle valve 12 from closing too much when the road surface is a high μ road.

Next, in the above embodiment, the F / C control of the internal combustion engine 2 is executed in order to suppress the output torque of the internal combustion engine 2 immediately after the occurrence of the acceleration slip, but the output torque is suppressed by the retard control of the ignition timing. Alternatively, the output torque may be suppressed by a combination of F / C control and ignition timing retard control.

Further, in the above embodiment, the target drive wheel speed VS is set based on the vehicle body speed VF obtained from the rotational speeds of the left and right driven wheels,
The acceleration slip of the drive wheel is detected from the deviation ΔV between the target drive wheel speed VS and the drive wheel speed VR, but as is well known in the art, the drive wheel speed is calculated from the vehicle body speed VF and the drive wheel speed VR. The slip ratio may be obtained, and the acceleration slip may be detected from the deviation between this value and the target slip ratio.
The target drive wheel speed may be obtained by multiplying the drive wheel speed by a predetermined acceleration, and the acceleration slip may be detected from the deviation between the target drive wheel speed and the drive wheel speed.

Further, in the above embodiment, the rotational acceleration ΔNE of the internal combustion engine is
Is configured to end the fuel cut control when becomes equal to or less than a predetermined value.However, the rotational acceleration ΔVR of the drive wheel is calculated instead of the rotational acceleration ΔNE of the internal combustion engine, and the rotational acceleration ΔVR of the drive wheel is equal to or less than the predetermined value. Even if the fuel cut control is terminated when the above condition occurs, the fuel cut control can be executed according to the road surface μ, and the same effect as that of the above embodiment can be obtained.

[Effects of the Invention] As described in detail above, in the acceleration slip control device of the present invention, when the acceleration slip detection means detects the acceleration slip and the throttle opening control means starts the opening / closing control of the throttle valve, The output suppressing means simultaneously starts the output torque control of the internal combustion engine by the ignition timing or the fuel supply amount, and thereafter controls the rotational acceleration of the internal combustion engine or the drive wheels until the rotational acceleration once falls below a predetermined value. Is to continue.

Therefore, according to the present invention, the control operation by the engine output suppressing means can be executed for the time corresponding to the road surface μ, and the operation of the engine output suppressing means causes the output of the internal combustion engine on the high μ road. It is possible to prevent the torquer from being excessively suppressed, or conversely, the output torque of the internal combustion engine cannot be sufficiently suppressed on the low μ road. Therefore,
With the engine output suppressing means, the response delay immediately after the start of the slip control by the throttle opening control means can be compensated very well, and after the control operation by the engine output suppressing means is completed, the control smoothly shifts to the slip control by only the throttle control. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a schematic configuration diagram showing the overall configuration of an acceleration slip control device of an embodiment, and FIG. 3 is a block diagram showing the configuration of an acceleration slip control circuit. FIG. 7 is a flow chart showing an acceleration slip control process executed by the acceleration slip control circuit, FIG. 5 is a diagram for explaining the operation, FIG. 6 is a flow chart showing another embodiment of the acceleration slip control process, and FIG. Is a diagram for explaining the operation, FIG. 8 is a diagram for showing the relationship between the counter CFC value showing the execution time of the fuel cut control and the road surface μ,
Is. M1 …… Drive wheel speed detection means (40 …… Drive wheel speed sensor) M2,22RL, 22RR …… Drive wheel M3 …… Acceleration slip detection means M4,2 …… Internal combustion engine, M5, 4 …… Intake passage M6… … Throttle valve (12 …… sub throttle valve) M7 …… Throttle opening control means M8 …… Rotary acceleration detection means M9 …… Engine output control means 20 …… Acceleration slip control circuit 26 …… Internal combustion engine control circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area F02P 5/15 F02P 5/15 B

Claims (1)

(57) [Claims] 1. A drive wheel speed detecting means for detecting a drive wheel speed, an acceleration slip detecting means for detecting an acceleration slip of the drive wheel generated during vehicle acceleration using the drive wheel speed as one parameter, and the acceleration slip. When the acceleration slip is detected by the detection means, the throttle valve provided in the intake passage of the internal combustion engine that drives the drive wheels is opened and closed until the acceleration slip does not occur on the drive wheels. In a vehicle acceleration slip control device including a throttle opening control means for controlling torque, a rotational acceleration detection means for detecting the rotational speed of the internal combustion engine or the driving wheels, and an acceleration slip detection means for the acceleration slip detection means. When the throttle opening control means starts opening / closing control of the throttle valve, the rotational acceleration detecting means detects the opening / closing control. The engine output control means for controlling the ignition timing or the fuel supply amount to suppress the output torque between the internal combustion engines until the rotational acceleration of the internal combustion engine or the drive wheels once falls below a predetermined value. A vehicle acceleration slip control device characterized in that