JPH07269391A - Acceleration slip controller of vehicle - Google Patents

Abstract

PURPOSE:To improve the responsiveness of control by opening/closing quickly an acceleration slip controller by conducting the opening/closing operation of a throttle valve by driving a DC motor so that frictional force between drive wheels and the road surface may become large at the time of vehicle acceleration on the basis of vehicle travel speed and the rotary state of the drive wheels. CONSTITUTION:In a case in which the rotary speeds of driven wheels 22, 23 increase/decrease more than the speed of change that can be generated in a normal state, torque to be transmitted to drive wheels 20, 21 is controlled to the optimum on the basis of a decision outcome. Also, the rotary speeds and rotary acceleration of the drive wheels 20, 21 are not controlled as they are, but controlled by adding various vehicular conditions to them and using angle advance drive wheel speed VWR, and standby speed VSB other than its upper and lower limit values is set, and the opening/closing control of a throttle valve 14 is carried out. Also, as its opening/closing is controlled by regulating the drive speed of a DC motor 12, slip at the time of acceleration can be controlled accurately, and quick responsiveness is possessed at an apter value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle acceleration slip control device for controlling slip of drive wheels during vehicle acceleration.

[0002]

2. Description of the Related Art Conventionally, an acceleration slip control device for suppressing engine output by controlling an opening of a throttle valve provided in an intake pipe of an internal combustion engine when a slip occurs on driving wheels during vehicle acceleration. Are known. In this type of device, when the throttle valve is driven by using the DC motor, the DC motor itself cannot generate the stationary torque for holding the throttle valve at the target opening. A speed reducing mechanism such as a worm gear is provided in the power transmission system up to and the throttle valve is kept at the target opening by utilizing the static friction force obtained by the speed reducing mechanism (Japanese Patent Laid-Open No. 59-68539). Issue).

That is, the DC motor is operated only when the throttle valve is opened and closed, and when the throttle valve reaches the target opening, the opening is maintained by using the static frictional force of the speed reduction mechanism.

[0004]

However, when the opening of the throttle valve is maintained by utilizing the static frictional force of the speed reduction mechanism as described above, the energization of the DC motor is started and the throttle valve is actually operated. It can be opened and closed only after the driving force of the DC motor exceeds the static friction force of the speed reduction mechanism by energization. Therefore, in the control as described above, there is a problem that it takes time to shift from the holding state to the opening / closing operation and the responsiveness of the acceleration slip control deteriorates.

The present invention has been made in view of the above problems, and controls the opening of a throttle valve by using a DC motor to accelerate the output of an internal combustion engine and thus the slip of drive wheels. An object of the slip control device is to open and close a throttle valve quickly to improve control response.

[0006]

SUMMARY OF THE INVENTION The present invention, which has been made in order to achieve the above object, provides a vehicle speed detecting means for detecting a traveling speed of a vehicle and a rotation state of driving wheels of the vehicle as illustrated in FIG. Drive wheel rotation state detecting means for detecting, a throttle valve provided in the intake passage of the engine of the vehicle,
A DC motor that opens and closes the throttle valve, and drives the DC motor based on the traveling speed and the rotation state of the drive wheels so that the frictional force between the drive wheels and the road surface increases when the vehicle accelerates. In a vehicle acceleration slip control device comprising a control means for controlling the engine output,
The control means calculates a target opening degree calculation means for calculating a target opening degree of the throttle valve based on the traveling speed and a rotation state of the driving wheels; and an actual opening degree of the throttle valve and the target opening degree. A current value control means for controlling the current value supplied to the DC motor so that the larger the deviation is, the larger the current value is, and the current value control means further reduces the deviation to zero. And controlling the current value to a predetermined current value larger than zero, the DC motor is given a driving force for withstanding the intake pipe pressure and holding the throttle valve at the target opening.
The gist is a vehicle acceleration slip control device.

[0007]

In the vehicle acceleration slip control device of the present invention having the above-described structure, the control means is
Based on the traveling speed of the vehicle detected by the vehicle speed detection means and the rotation state of the drive wheels detected by the drive wheel rotation state detection means, the frictional force between the drive wheels and the road surface increases during acceleration of the vehicle. To open and close the throttle valve
The C motor is driven to control the engine output.

In the control means, the target opening calculation means is
The target opening of the throttle valve is calculated on the basis of the traveling speed and the rotation state of the driving wheels, and the current value control means has a large deviation according to the deviation between the actual opening and the target opening of the throttle valve. The current value supplied to the DC motor is controlled so that the current value increases.

Further, particularly in the present invention, when the deviation between the actual opening of the throttle valve and the target opening is zero, the current value control means controls the current value of the DC motor to a predetermined current value larger than zero. Then, the DC motor is given a driving force for withstanding the pressure in the intake pipe and maintaining the throttle valve at the target opening.

That is, although the DC motor itself cannot generate a stationary torque which continues to stop at an arbitrary rotational position due to the energized current, when energizing the DC motor to open and close the throttle valve, the pressure in the intake pipe causes Since a force in the direction opposite to the opening / closing direction is applied to the throttle valve, in the present invention, when the DC motor is driven to control the throttle valve to the target opening, the actual opening and the target opening are simply compared with each other. The current value of the DC motor is not set according to the deviation of, but even when the deviation becomes zero, a predetermined current is supplied to the DC motor to
The driving force for holding the throttle valve at the target opening is endured against the pressure in the intake pipe.

Therefore, according to the present invention, the throttle valve can be maintained at the target opening degree without providing a speed reducing mechanism such as a worm gear in the power transmission system from the DC motor to the throttle valve. Therefore, it becomes possible to quickly shift from the state in which the throttle valve is held at the target opening degree to the opening / closing control, and it is possible to improve the responsiveness of the acceleration slip control.

[0012]

EXAMPLES Hereinafter, in order to more specifically describe the present invention, examples will be described in detail. First, FIG. 2 is a schematic configuration diagram showing an engine periphery and a wheel portion of a vehicle in which the vehicle acceleration slip control device of the present embodiment is mounted. 1 is an engine, 2 is a piston, 3 is a spark plug, and 4 is a spark plug. Intake valve, 5 fuel injection valve, 6 surge tank, 7 air flow meter,
Reference numeral 8 represents an air cleaner. In the present embodiment, in addition to the first throttle valve 10 that is conventionally provided in the intake passage between the air flow meter 7 and the surge tank 6 to adjust the intake amount in conjunction with the accelerator pedal 9, DC A second throttle valve 14 that is driven by a motor 12 and adjusts an intake amount like the first throttle valve 10 is provided, and the accelerator pedal 9 has an idle switch 16 that is turned on when a depression operation is not performed. Is provided.

On the other hand, 20 to 23 indicate wheels of the vehicle, and 20 and 21 indicate that the power of the engine 1 is transmitted through a transmission 25, a propeller shaft 26, etc.
Left and right drive wheels for driving the vehicle are shown, and 22 and 23 are left and right driven wheels that are rotated as the vehicle runs. And the left driven wheel 22 and the right driven wheel 23
Driven wheel speed sensors 27 and 28 for detecting the rotational speeds of the left and right drive wheels 21, respectively. The transmission 25 has drive wheels for detecting the average rotational speeds of the left drive wheel 20 and the right drive wheel 21. A speed sensor 29 is provided.

Reference numeral 30 denotes a drive control circuit, which receives various detection signals from the accelerator sensor 16, the left driven wheel speed sensor 27, the right driven wheel speed sensor 28, and the driving wheel speed sensor 29, and causes an acceleration slip during vehicle acceleration. Slip control is executed in which a drive signal is output to the DC motor 12 that adjusts the opening degree of the second throttle valve 14 to control the engine output so that maximum acceleration can be obtained without occurrence.

Here, in the present embodiment, the drive control signal circuit 30 is constructed by using a microcomputer, and the description of the drive control circuit 30 is as follows.
It can be represented as shown in FIG. In the figure, 31
Is a central processing unit (CPU) that inputs and calculates data detected by the above-mentioned sensors according to a control program, and performs processing for driving and controlling the DC motor 12, and 32 stores data such as the control program and maps. The read-on memory (ROM) 33 is a random access memory (RA) for temporarily reading and writing data from the above-mentioned sensors and data necessary for arithmetic control.
M) and 34 are CPs for the output signals of the waveform shaping circuit and each sensor.
U31 is an input section provided with a multiplexer or the like for selectively outputting, U is an output section provided with a drive circuit for driving the DC motor 12 in accordance with a control signal from the CPU 31, 36 is a C
A bus line that connects various elements such as the PU 31 and the ROM 32, the input unit 34, and the output unit 35 to serve as a path for various data,
Reference numerals 37 respectively denote power supply circuits for supplying power to the above respective parts.

Next, the drive control circuit 3 configured as described above.
The slip control executed at 0 will be described based on the flowchart of the control program shown in FIG. This program is repeatedly executed by the CPU 31 when the starter switch of the vehicle is turned on.

First, when the processing of this program is started, initialization processing such as clearing the contents of the RAM 33 and resetting each flag and counter is executed (step 100),
Prepare for the following processing. Next, the watchdog timer (WD) for self-diagnosing the malfunction of the CPU 31 is reset (step 110), and the operation of the drive control circuit 30 is confirmed. Step 120 and step 130
Is to confirm the operation of various sensors and actuators used in this control, and the check is performed every time a predetermined period TB has passed (step 120) (step 13).
0), if TB has not yet elapsed, the process directly proceeds to step 140 and thereafter.

In step 140, it is determined whether or not the idle switch 16 is in the ON state, that is, whether or not the depression operation of the accelerator pedal 9 is released. Therefore, it is determined whether or not the control of this control program is necessary depending on the state of this switch. It is a thing. If the operation of the accelerator pedal 9 is released, the process returns to step 110 again to repeat the operation confirmation of each device, and the process proceeds to the next step 150 only when the idle switch 16 is off.

In this step 150, the output of each sensor for detecting the running state of the vehicle which is the condition for mode determination in the following control is taken in. The output of each sensor is the output VWFL of the left driven wheel speed sensor 27, the output VWFR of the right driven wheel speed sensor 28, and the output VWRr of the drive wheel speed sensor 29.

In the following step 160, the speeds serving as the reference for the following four controls are calculated and calculated from the above three types of information.
First, the approximate vehicle body speed VSO of the vehicle is calculated from the equation (1). VSOn = MED (VWO, VSOn-1-αD · t, VSOn-1 + αU · t) (1) where the subscript n is the order of calculation, VWO = (VWFR + V
WFL) / 2, αD is the vehicle body standard deceleration, αU is the vehicle body standard acceleration, and MED () is an intermediate value.

That is, the approximate vehicle body speed VSOn is obtained by adding the acceleration / deceleration (αD / αU) that the vehicle body can take in the normal state to the previously calculated value VSOn-1, and the measured left and right driven wheels. It is calculated as an intermediate value of three values of the average value VWO of the speeds VWFR and VWFL. As a result, even if the driven wheel rotates at a high speed regardless of the vehicle body speed, such as when the vehicle is traveling on a rough road, the vehicle body speed is not erroneously detected, and the accuracy can be improved.

The second calculated speed is the advance drive wheel speed VW.
R, which is calculated from the equation (2). VWR = AR · VWRr + AD · αWRr (2) where AR and AD are constants, VWRr is driving wheel speed,
αWRr is the driving wheel acceleration.

That is, the advance drive wheel speed VWR is equal to the drive wheel 2
It is defined as the sum of the rotational speeds and rotational accelerations of 0 and 21 that are appropriately weighted (the magnitudes of the values of AR and AD). Then, the constant AR in the equation (2)
The values of AD and AD are respectively determined experimentally or theoretically, and by appropriately selecting the values of the constants AR and AD, how much the driving wheel speed and the driving wheel acceleration are included in the control described later. It is decided whether to return. For example, the conditions for determining the values of the constants AR and AD include the magnitude of the output torque of the engine of the vehicle, the moment of inertia, and the transmission delay until the output torque of the engine is actually transmitted as the driving force of the drive wheels. There is.

Thirdly, two types of reference speeds, a lower limit reference speed VML and an upper limit reference speed VMH are (3),
It is calculated by the equation (4). VML = AML · VSOn + ΔVML (3) VMH = AMH · VSOn + ΔVMH (4) where AML and AMH are constants, ΔVML and ΔVM
H is a constant.

These two reference speeds are reference values for comparison with the advance drive wheel speed VWR. (3),
As is clear from the equation (4), the relationship is parallel to the approximate vehicle body speed VSO. Further, the constants in the respective formulas are appropriately selected theoretically or experimentally as to how much the advance angle drive wheel speed VWR can be accelerated in the optimum slip state.

Finally, the standby speed VSB is calculated from the equation (5) as the fourth calculated speed. VSB = ASB · VSOn + ΔVSB (5) where ASB and ΔVSB are constants.

This standby speed VSB gives an operation start speed for operating the slip control device of this embodiment, and the slip control is executed when VWR becomes equal to or higher than VSB. VSO, VML, VM
As an example of the values of H and VSB, when VSO monotonously increases in FIG. 5 (A) (when the vehicle body is accelerated)
FIG. Here, the constants in the equation (1) are set to αD = 1 [G] and αU = 0.4 [G], and the constants in the equations (3) and (4) are AML = 1.
0, ΔVML = 25 [km / H], AMH = 1.0, Δ
When VMH = 10 [km / H], the constant of the equation (5) is AS
B = 1.0 and ΔVSB = 15 [km / H] are set. It should be noted that the setting of this value is made in consideration of all the vehicle body conditions such as the weight of the vehicle body, the load shared by the driving wheels, the air resistance of the vehicle body, and the delay time of the driving force transmission to the driving wheels 20 and 21. It goes without saying that the optimum value is calculated according to the internal combustion engine system to which the present embodiment is applied.

Upon completion of the various checks and input of information and processing as described above, step 170 is subsequently executed to determine whether the advance drive wheel speed VWR becomes equal to or higher than the standby speed VSB and whether slip control should be executed. . Then, if VWR <VSB, it is determined in step 180 whether or not the slip control was being executed last time by the flag F.
Judging from the contents of S, if FS = 0, the slip control has not been performed the previous time, and it is determined that no control is required, and the process returns to step 110 described above. On the other hand, if FS = 1, control is still required. In some cases, the process proceeds to step 300 and subsequent steps, which will be described later. When VWR ≧ VSB, it is determined that the condition for executing the slip control is satisfied, and the process proceeds to step 190, and it is determined from the contents of the flag FF whether or not the condition for the slip control is satisfied for the first time. . At the time of starting the slip control, special processing of steps 200 to 220 described later is required, so the determination is made based on the content of this flag FF.
Only when FF = 0, the process proceeds to step 200, and otherwise (FF = 1), the process proceeds to step 300 and the subsequent steps.

First, the processing at the start of slip control will be described in detail. In step 200, the two flags FF and FS described above are set to "1" and the fact that the slip control is started is stored. Then, the opening degree θM of the second throttle valve 14 is changed to θTM. FIG. 5C shows this relationship. That is, VWR is V
When SB is exceeded, the DC motor 12 is driven so that the second throttle valve 14 is closed from the fully open state where it is not initially controlled to the opening θTM. But D
Since it takes time for the C motor 12 to actually drive the second throttle valve 14 to the closing side, the actual opening degree θM of the second throttle valve 14 is gradually closed as shown by the solid line in FIG. 5C. I will go. Further, the process proceeds to step 210, where it is judged whether or not the advance drive wheel speed VWR is larger than the reference speed VMH, and if VWR
> VMH causes extremely large slips on drive wheels 20, 2
The second throttle valve 14 is presumed to occur at 1 and the second throttle valve 14 is controlled to be closed to a preset minimum value θMIN (step 220), and the process proceeds to step 300. Also, V
If WR ≦ VMH, it is determined that the above-described approximately anti-close control with θM = θTM is sufficient, and the process proceeds to step 300. still,
FIG. 5C shows the case where VWR> VMH is determined in step 210. Since VWR exceeds VMH by the time θM reaches θTM, θM is continuously controlled toward θMIN. It shows what is being done.

The process after step 300 describes the process which is always executed as the slip control. First, in step 300, the advance drive wheel speed VWR and the lower limit reference speed V
A magnitude comparison with ML is performed. And VWR <VM
If it is L, it is determined that the closing control of the second throttle valve 14 is excessive, and the open mode described later is set in step 310 to control the opening of the second throttle valve 14, and the following control is performed. It is executed based on the open mode. Next, the counter C for counting the time during which the control in the open mode is executed is counted up (step 320), and it is determined whether or not the content of the counter C is larger than the preset period CB. The judgment is made in step 330. The open mode means the second throttle valve 14
Is a mode for controlling the opening of the second throttle valve 1
When 4 is fully opened, the output control of the engine 1 is performed only by the first throttle valve operated by the driver.
Slip control is no longer needed. Therefore, when the period of the open mode is sufficiently continuous (C> CB), the slip control is ended, so that all of the flags FF, FS, the counter C, and the like set in the control so far are cleared in step 340. , Reset and return to step 110 again. If this period has not elapsed, the process proceeds to the control process of the DC motor 12 in steps 500 to 530 described later.

On the other hand, in step 300, VWR ≧ VML
If it is determined that it is determined in step 350, whether the advance drive wheel speed VWR is higher than the upper limit reference speed VMH. Then, if VWR ≧ VMH, the output of the engine 1 is too large and the drive wheels 20, 2, as described above.
If an excessive acceleration slip occurs in No. 1, processing steps 360 to 3 for controlling the closing of the second throttle
80 is executed.

First, at step 360, a target value (target opening) θMd of the opening is calculated to what extent the second throttle valve 14 should be controlled to be closed. This target value θM
d is calculated by the equation (6). θMdn = θMdn-1 + K · dVn (6) where the subscript n is the order of calculation K is a constant where dVn is the difference (VML) between the lower limit reference speed VML and the advance drive wheel speed VWR in the immediately preceding open mode. -V
Represents the maximum value of WR), and θMdn−1 represents the previously calculated target opening. That is, the advance drive wheel speed VW
If R changes as shown in FIG. 5 (A), dVn
Indicates the values of dV1, dV2, dV3, ... As shown in the figure, and the value obtained by adding the value obtained by multiplying dVn in the immediately preceding open mode by a constant K to the previous target opening θMdn-1 is added. The target opening θMdn is set. Therefore, the target opening degree θMdn of this time is set to a larger value as the value of dVn in the immediately preceding open mode is larger, whereby the advance drive wheel speed VWR is set to the upper limit reference speed VMH and the lower limit reference speed. It is designed to stably converge with VML. It should be noted that the constant K for weighting the value of dVn is determined in conformity with various vehicle conditions in the same manner as the constants in the above-described equations, and is determined as shown in FIG.
Shows the case where K = 0.3 is set.

In this way, the second throttle valve 14
When the target opening θMd of is calculated, the next step 370
In the following control, after the fact that the closed mode is set is set, the above-mentioned counter C is reset (step 380), and similarly to the previous time, the process proceeds to the DC motor control processing of steps 500 to 530.

Next, the control when it is determined in step 350 that VWR <VMH, that is, when VML≤VWR <VMH, will be described. If this condition is satisfied, the drive wheels 20,
Reference numeral 21 indicates a state in which acceleration can be performed in an optimum slip state. Therefore, the holding mode in which the previous opening is maintained without changing the opening of the second throttle valve 14 is set (step 410). However, in the present embodiment, before the processing of step 410, it is first determined in step 390 whether or not the previous time was the closed mode, and if it was the closed mode, the target opening degree when the open mode is next changed. The calculation of θMD is executed in advance (step 400), and the mode setting of step 410 is performed. Target opening θMD executed in step 400
Is calculated by the equation (7).

ΘMDn = θMDn-1 −k · DVn (7) where the subscript n is the order of calculation and k is a constant. Here, DVn is the difference (VWR-V) between the advance drive wheel speed VWR and the upper limit reference speed VMH in the immediately previous closed mode.
The maximum value of MH) is represented, and θMDn-1 represents the target opening calculated last time. That is, the advance drive wheel speed VW
If R changes as shown in FIG. 5 (A), DVn
Indicates the values of DV1, DV2, DV3, ... As shown in the figure, and the value obtained by subtracting the value obtained by multiplying DVn in the immediately previous closed mode by a constant k is subtracted from the previous target opening θMDn-1. The target opening θMDn is set. Therefore, the target opening degree θMDn of this time is set to a smaller value as the value of DVn in the immediately previous closing mode is larger, whereby the advance drive wheel speed VWR is set to the upper reference speed VMH and the lower reference speed. It is designed to stably converge with VML. The constant k for weighting the value of DVn is determined in conformity with various vehicle conditions as in the case of the constant K described above.
Shows the case where k = 0.3 is set.

FIG. 5 shows the relationship between the three types of mode settings, the open mode, the close mode, and the hold mode described above, and the target opening of the second throttle valve 14 in the open / close mode.
Represented in (A), (B) and (C). When the advance drive wheel speed VWR changes as shown in FIG. 5 (A), FIG.
The control mode is set as described above, and the target opening degree θMDn or θMdn as shown by the alternate long and short dash line in FIG. 5C is calculated. After the control mode (open / close / hold) and the target opening θMD or θMd of the second throttle valve are determined in this way, the DC motor 12 is controlled Step 500-
The process of step 530 is executed.

First, in step 500, the DC motor 1
It is determined whether or not the holding mode in which 2 is not required to be driven, and if it is the holding mode, in step 510 DC
The motor 12 is stopped and the process returns to step 110 again. Open
In the closed mode, the operating speed of the DC motor 12 is calculated in advance in step 520, and the second throttle valve 14 is actually driven to the target opening θMD or θMd at the operating speed obtained as a result of the calculation (step 530). )do it,
Then, the process returns to step 110 again.

Here, details of the control of the DC motor 12 will be described with reference to FIG. 6, the horizontal axis represents the difference between the actual opening degree θM of the second throttle valve 14 and the target opening degrees θMD and θMd, that is, the second throttle valve 1 actually.
4 is a graph in which the vertical axis represents the absolute value of the armature current ID supplied to the DC motor 12, that is, the driving force, when the open / close control of 4 is performed. Therefore, the value of the armature current ID of the DC motor 12 is a reversed value to the left and right of the center of the graph (the control amount is “0”). Then, as described above, the open / close mode and the target opening θMD in each mode,
When θMd is determined, the CPU 31 drives the motor by determining the armature current to be supplied to the DC motor 12 from the graph of FIG.

As is apparent from FIG. 6, the target opening θMD
Alternatively, when the difference between θMd and the actual opening degree θM is large, the driving force becomes large, the second throttle valve 14 is controlled at a large speed, the speed becomes smaller as it approaches the target value, and when the target value is reached. Prevents overshoot.

Further, even when the target opening is reached and θM = θMd or θM = θMD (when the control amount in the figure is “0”), the driving forces Fd and FD are continuously applied to the DC motor 12. . This is a stationary driving force that is given to withstand the pressure in the intake pipe and maintain a constant opening because the DC motor 12 itself cannot generate a stationary torque that continues to stop at an arbitrary rotational position. At this time, FD> Fd is set because the second throttle valve 14 requires a larger torque when it is controlled to the open side than when it is controlled to the closed side by the negative pressure of the intake pipe. .

Controlling the DC motor 12 in this manner does not require the use of an expensive actuator such as a stepping motor which has a stationary torque by itself, and the cost of generating a stationary torque through a worm gear or the like is the second cost. (2) It is an extremely effective means without impairing the control speed of the throttle valve 14.

As described above, in the slip control executed by the acceleration slip control device of this embodiment, the driven wheel speed sensors 27, 28 are used to calculate the approximate vehicle speed VSO.
Left and right driven wheel speeds VWFR and VWF detected by
The average value VWO as a temporary vehicle body speed obtained by averaging L and the value VSOn- which is obtained by adding the previous calculated value VSOn-1 and the deceleration / acceleration (αD / αU) that can be taken when the vehicle body is in the normal state, respectively.
An intermediate value of three values of 1-αD · t and VSOn-1 + αU · t is set as the approximate vehicle body speed VSOn this time, and the upper limit reference speed VMH, the lower limit reference speed VML, and the standby state are set based on the approximate vehicle body speed VSOn. The speed VSB is calculated. Then, the VMH calculated in this way,
VML, VSB are compared with the advance drive wheel speed VWR calculated based on the drive wheel speed VWRr detected by the drive wheel speed sensor 29, and the second throttle valve 14 is opened / closed according to the comparison result. The opening / closing mode and the target opening degrees θMD and θMd in each mode are set.

Therefore, the vehicle runs on a bad road with a large unevenness of the road surface or a hydroplane phenomenon occurs, and the rotational speeds of the driven wheels 22 and 23 increase or decrease at a speed higher than the change speed that can occur in the normal state. Even in this case, the value of the approximate vehicle body speed VSOn calculated this time is equal to the previous value VSOn-1 of the deceleration / acceleration (αD · α)
USO) -added value VSOn-1 -αD · t, VSOn-
It will be limited to 1 + αU · t, and accordingly,
Upper limit reference speed VM compared with the advance drive wheel speed VWR
Changes in H, the lower limit reference speed VML, and the standby speed VSB are also limited.

Therefore, according to the acceleration slip control device of the present embodiment, even when the rotational speeds of the driven wheels 22 and 23 increase or decrease above the change speed that can occur in the normal state,
It becomes possible to optimally control the torque transmitted to the drive wheels 20, 21 based on the determination result in each processing of steps 170, 210, 300, 350. That is, according to the acceleration slip control device of the present embodiment, it is determined that slip has occurred even though the drive wheels 20, 21 have not slipped, or conversely, the drive wheels 20, 21 have slipped. Nevertheless, it is prevented that it is determined that the slip has not occurred, and the slip control of the drive wheels 20 and 21 at the time of vehicle acceleration can be accurately performed.

Further, in the acceleration slip control device of the present embodiment, the rotational speeds and rotational accelerations of the drive wheels 20 and 21 are not used for control as they are, but various vehicle conditions are added to them and equation (2) is used. The control is performed using the advance drive wheel speed VWR calculated as follows. Therefore, drive wheel 2
By estimating the rotational states of 0 and 21 in advance, control with good responsiveness and stability can be achieved.

Further, in this embodiment, the standby speed VSB is set in addition to the upper and lower limit values of the advance drive wheel speed VWR, and when the vehicle body is started, the advance drive wheel speed V is higher than this standby speed.
When WR is reached, immediately the second throttle valve 14
Is controlled to a semi-closed state, and the advance drive wheel speed VWR is still
When exceeds the upper limit value, it is controlled to almost the fully closed state. Therefore, particularly when the vehicle body starts to start and the inertial force of the vehicle body is large and the drive wheels are likely to slip, the effect is further enhanced, and the output of the engine 1 can be prevented from becoming excessive.

Regarding the opening / closing control of the second throttle valve 14, the DC motor 12 is not simply driven to open / close at a constant speed, but the previous advance drive wheel speed VWR is observed. When it takes time to calculate the target openings θMDn and θMdn according to the values (DVn, dVn) and drive the actual opening θM to reach the target opening, the DC motor 1
2 is given a larger driving force (FIG. 6). Therefore, the slip control has a more appropriate value and quick response.

In particular, in this embodiment, a predetermined armature current is supplied to the DC motor 12 when the target opening reaches the actual opening θM, that is, when the deviation becomes zero. As a result, the DC motor 12 is provided with a driving force for the second throttle valve 14 to withstand the pressure in the intake pipe and maintain a constant opening (FIG. 6), so that the second throttle valve 14 is held at the target opening. Has been done.

Therefore, according to the present embodiment, although it is inexpensive and has a high operating speed, it cannot generate static torque by itself.
The C motor 12 can be used as a drive motor for the second throttle valve 14 without using a speed reducing mechanism for generating a static torque. As a result, according to this embodiment, it becomes possible to quickly shift from the state in which the second throttle valve 14 is held at the target opening to the opening / closing control, and the response and stability of the slip control can be achieved. We can provide the best system for you.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a schematic configuration diagram showing an engine periphery and a wheel portion of a vehicle equipped with an acceleration slip control device of an embodiment.

FIG. 3 is a block diagram illustrating a configuration of a drive control circuit according to an embodiment.

FIG. 4 is a flowchart showing a control program of the embodiment.

FIG. 5 is an explanatory diagram showing a control operation of the embodiment.

FIG. 6 is an explanatory diagram showing a DC motor control of the embodiment.

[Explanation of symbols]

12 ... DC motor 14 ... Second throttle valve 16 ... Idle switch 27 ... Left driven wheel speed sensor 28 ... Right driven wheel speed sensor 29 ... Driving wheel speed sensor 30 ... Drive control circuit

Claims (1)

[Claims] 1. A vehicle speed detection means for detecting a traveling speed of a vehicle, a drive wheel rotation state detection means for detecting a rotation state of drive wheels of the vehicle, and a throttle valve provided in an intake passage of an engine of the vehicle. A DC motor that opens and closes the throttle valve, and drives the DC motor based on the traveling speed and the rotation state of the drive wheels so that the frictional force between the drive wheels and the road surface increases when the vehicle accelerates. In a vehicle acceleration slip control device including a control unit for controlling an engine output, the control unit calculates a target opening degree for calculating a target opening degree of the throttle valve based on the traveling speed and a rotation state of driving wheels. To the DC motor so that the larger the deviation, the larger the current value, depending on the deviation between the actual opening of the throttle valve and the target opening. A current value control means for controlling a current value to be supplied, wherein the current value control means controls the current value to a predetermined current value larger than zero when the deviation is zero, An acceleration slip control device for a vehicle, comprising: applying a driving force to a motor to withstand the pressure in the intake pipe and hold the throttle valve at the target opening.