JP2942566B2 - Vehicle slip control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Industrial Application Field] The present invention is intended to prevent a decrease in side force when an engine brake is applied at the time of turning to achieve good vehicle running stability. Is what you do.

[Prior Art] In order to prevent idling of driving wheels generated at the time of rapid start of an automobile, a slip ratio S determined from a traveling speed Vb of a vehicle and a driving wheel speed Vd obtained from a driven wheel is set within a predetermined range. A device for controlling the opening of a throttle valve (traction control) is known (JP-A-62-121839).
No.).

Also, as a similar technique, the engine output is controlled so that the lateral acceleration of the vehicle does not exceed a predetermined limit value in order to prevent the vehicle from spinning due to idling of the drive wheel when the vehicle turns and side force is reduced. A device is also known (see
62-10437).

In both of these technologies, in order to prevent the drive wheels from slipping due to excessive engine output, the opening degree of the throttle valve is reduced by an electric actuator, and the engine output is reduced.

[Problems to be Solved by the Invention] Conversely, measures have been proposed for inconvenience due to an excessively small engine output. That is, when the engine generates negative torque (torque in the deceleration direction of the vehicle given from the engine to the drive wheels) on a low friction road such as an icy road, that is, when the drive wheels slip due to engine braking, the engine output is reversed. To reduce the slip of the drive wheels,
This is to ensure the stability of running the vehicle.

However, even if control to increase the engine output is performed to prevent the drive wheels from slipping due to the engine brake, the stability of the vehicle may decrease when the vehicle is turning. Was found to be insufficient.

[Purpose] An object of the present invention is to prevent a decrease in vehicle stability caused by engine braking during turning.

Configuration of the Invention [Means for Solving the Problems] As shown in a basic configuration diagram of FIG. 1, a vehicle slip control device of the present invention includes an accelerator pedal that is adjusted by an occupant, and an occupant stepping on the accelerator pedal. Signal conversion means for converting an operation state into an electrical signal; power generation means M2 mounted on a vehicle for generating power for driving the vehicle via driving wheels M1; Power adjusting means M3 for adjusting the amount of power generated by the power generating means in accordance with the electric signal; turning state detecting means M4 for detecting a turning state of the vehicle;
A negative torque detecting means M5 for detecting that the power generating means is applying a negative torque in the deceleration direction of the vehicle to the drive wheels; and the negative torque detecting means detects the negative torque. In this case, the greater the degree of the turning state of the vehicle, which is the result of detection by the turning state detecting means, the more the adjustment amount of the power generation amount is reduced in the direction of decreasing the negative torque, which is the deceleration direction of the vehicle. A variable control means M6 for executing the power adjustment means so as to control the power generation amount to change the adjustment amount of the power generation amount, and when the adjustment amount variable control of the power generation amount is performed by the variable control means. And limiting means M7 for limiting the power given to the drive wheels so as not to be substantially positive torque.

[Action and effect of the invention]

With the operation of the accelerator pedal operated by the occupant, the signal converting means converts the operation of the accelerator pedal into an electric signal. The power adjusting means is a so-called linkless throttle type engine control device for adjusting the power generated by the power generating means in accordance with the electric signal. In such a device, when the vehicle is turning when the power is reduced and an operation of decelerating the vehicle occurs, that is, an engine braking operation, the side force of the tire is reduced. The reduction of the side force changes according to the degree of the turning state of the vehicle. When the negative torque is detected by the negative torque detecting means, the power generation amount is changed by the variable control means according to the magnitude of the turning state. Make adjustments. At this time, in the linkless throttle, the accelerator pedal and the throttle valve, which is a concrete power control means, are simply connected by an electric signal, and there is no mechanical link mechanism. Without doing so, it is substantially possible to adjust the throttle valve from fully open to fully closed by the power adjusting means with the variable control means. Therefore, the controllability in the engine output control in consideration of the negative torque and the turning state is very high. Further, if the power applied to the driving wheels is substantially prevented from becoming a positive torque by the restricting means, it is possible to prevent a decrease in the vehicle from being changed from deceleration to acceleration in the opposite state for some reason, and to achieve a more stable running. The state can be secured. If the throttle valve can be controlled substantially from fully closed to fully open, there is a merit that controllability is enhanced even when the limiting means is adjusted so as not to have a positive torque.

Also, when the engine output control is performed by the variable control means in consideration of the negative torque and the turning state, if it is executed during the traction control, the slip state due to the negative torque associated with the acceleration slip control and the rotation associated with the turning Control of the engine output in consideration of both the slip state can be realized. At this time, the traction control is usually executed when the vehicle starts moving, and the acceleration slip at the time of starting the vehicle often becomes very large. This is because the depression of the accelerator pedal when starting from a stopped state of the vehicle is often relatively inaccurate compared to when the vehicle is running. For example, if the current state is a stopped state, the vehicle is the most stable state. This is because the degree of caution regarding pedal depression in the state is different from the degree of caution regarding accelerator operation during traveling, which is less stable than when the vehicle is stopped.
Therefore, it is conceivable that the negative torque during the traction control is very large, and by executing the engine output control in consideration of both the negative torque and the turning state during the traction control, the vehicle stability can be most effectively reduced. Can be secured.

FIG. 2 is a schematic configuration diagram showing an embodiment of the vehicle slip control device of the present invention. In the following, negative torque or negative torque refers to the torque applied to the drive wheels (the right rear wheel 31 and the left rear wheel 33) from the internal combustion engine 1 in the direction of decelerating the vehicle, as described above. ing.

An internal combustion engine (hereinafter simply referred to as an engine) 1 is a spark ignition type four-cylinder gasoline engine, which is mounted on a vehicle. An intake pipe 3 and an exhaust pipe 5 are connected to the engine 1. The intake pipe 3 includes a collecting part 3a connected to an air cleaner (not shown), a surge tank 3b connected to the collecting part 3a, and a branch part 3c branched from the surge tank 3b corresponding to each cylinder of the engine 1. .

The collecting portion 3a is provided with a throttle valve 7 for adjusting the amount of air taken into the engine 1 to adjust the output generated by the engine 1. The throttle shaft of the throttle valve 7 has a step motor 9 for adjusting the opening of the throttle valve 7 and a throttle sensor for detecting the opening of the throttle valve 7.
11 and linked to.

The step motor 9 is provided with a motor fully closed sensor 9a for detecting a fully closed position of the motor 9.

An intake air temperature sensor 13 for detecting the intake air temperature is provided at a position upstream of the throttle valve 7 in the collecting section 3a.

The surge tank 3b is provided with an intake pipe pressure sensor 14 for detecting the pressure in the intake pipe 3, and each branch 3c is provided with an electromagnetic fuel injection valve 15 for injecting fuel into the branch 3c. Have been.

Further, the engine 1 is provided with a spark plug 17 for igniting the air-fuel mixture taken in corresponding to each cylinder. The spark plug 17 is connected to a distributor 19 via a high-pressure cord, and the distributor 19 is electrically connected to an igniter 21. The distributor 19 is provided with a rotation sensor 19a that outputs a signal synchronized with the engine rotation.

Further, the engine 1 is provided with a water temperature sensor 23 for detecting the temperature of cooling water for cooling the engine 1.

The power generated by the engine 1 is a torque converter 25,
The driving force is transmitted to a right rear wheel 31 and a left rear wheel 33 which form driving wheels via a transmission 27, a differential gear 29, and the like. The transmission 27 is provided with a gear position sensor 27a that outputs a gear position signal corresponding to the gear position.
A wheel speed sensor 31 for detecting a wheel rotation speed is provided on each of a left rear wheel 33 and a right front wheel 35 and a left front wheel 37 formed by a driven wheel.
a, 33a, 35a, and 37a are provided.

The steering angle sensor 39a detects the steering angle SA of the front wheels 35, 37 that changes with the operation of the steering 39. As shown in FIG. 20, the steering angle SA is centered on the turning center CC of the vehicle, and the right front wheel 35 and the left front wheel
It is indicated by an angle between a tangent Ld on the intermediate point FC and a vehicle direction Md of a circle passing through the intermediate point FC of 37.

The above-described sensors and an accelerator operation amount sensor 41a that outputs a signal corresponding to the operation amount of the accelerator pedal 41, an accelerator full-close sensor 41b that detects a state in which the accelerator pedal 41 is released and the accelerator is fully closed, and a brake A signal from a brake sensor 43a that is turned on when the pedal 43 is depressed is input to an electronic control unit (ECU) 50. The ECU 50 drives the step motor 9, the injection valve 15, and the igniter 21 based on these signals. Output a signal.

The ECU 50 performs various calculations.The CPU 50a, a RAM 50b in which data necessary for the calculations in the CPU 50a are temporarily stored, and the ECU 50 is also necessary in the calculations in the CPU 50a. The RAM 50c in which data that needs to be retained even after being turned off is stored in the RAM 50c, and the ROM 50 in which constants and the like used in calculations in the CPU 30a are stored in advance.
d, input port 50e for inputting signals from each of the above sensors
CPU 50a according to the data content of input counter 50f, timer 50g for measuring time, input counter 50f and timer 50g.
Control unit 50h, step motor 9,
Injection valve 15, output circuits 50i, 50j, 50k for outputting signals for driving igniter 21, bus line 50l serving as a data transmission path between the above ECU components, battery 53 and key switch
The power supply circuit 50m is connected via the power supply circuit 51 and supplies power to each element other than the RAM 50c, and the power supply circuit 50n is directly connected to the battery 53 and supplies power to the RAM 50c. Hereinafter, a drag control process executed by the ECU 50 will be described with reference to a flowchart.

FIG. 3 is a schematic flowchart of the program. First, steps 2000 and 3000 are executed as initialization processing. That is, when the power is turned on, it is started by reset, and in step 2000, each control variable is initialized. Step 30
At 00, the actuator operating position is initialized and an operation check known as a primary check is performed.

In the next step 4000, as signal input-based processing, various digital and analog signals are input, a vehicle traveling state is determined, and data corresponding to the determination is created and a flag is set. Subsequently, in step 5000, a fuel injection amount for fuel injection execution processing is calculated as fuel injection base processing, and in step 6000, a target throttle opening is calculated as throttle control base processing. Steps
After 6000 ends, it shifts to the state of waiting for a periodic interrupt. In step 2000, a periodic interrupt is set in the timer 50g of FIG. 2 to an interrupt interval time (for example, 10 ms). Thereafter, the interrupt occurs every 10 ms, and steps 4000 and thereafter are started.

Next, the details of the signal input base processing in step 4000
This will be described with reference to the drawings. In this process, first, at step 4100, the intake air temperature THA of the analog signal, the accelerator operation amount AA, and the intake pipe pressure P
M, the cooling water temperature THW, the throttle opening TA, the steering angle SA, and the gear position GP are inputted. In step 4200, a digital accelerator full close signal IDL, a motor full close signal MOFF, and a brake depression signal BRK are inputted. Next, in step 4300, the vehicle speed signal processing is performed. Here, FIG. 5 (in this example, the interruption time interval due to the output signal of the wheel speed sensor 35a is detected [step 4210], and the right front wheel speed VFR is obtained therefrom [step 4220]. The same applies to the other wheel speeds, which are not shown in the figure.) The right front wheel speed VFR, left front wheel speed VFL,
From the right rear wheel speed VRR and the left rear wheel speed VRL, a target drive wheel speed Vt, a drag control start speed Vh, and the like required for control are calculated.

The details of step 4300 are as shown in FIG.
At 4310, the vehicle speed V at the center of the right rear wheel 31 and the left rear wheel 33, that is, the position of the differential gear 29, is determined by the rotation speed VFR of the right front wheel 35, the rotation speed VFL of the left front wheel 37, and the steering angle SA, which are driven wheels. Is obtained from the following equation.

V = [cosSA + (B / 2L) ・ sinSA] ・ [(VFR + VFL) / 2] where “L” is the wheelbase of the vehicle and “B” is the rear wheel 3
Shows a tread width of 1,33.

Next, in step 4320, the vehicle speed V is compared with the first determination speed KS. If V ≧ KS, the process proceeds to step 4330, and if V <KS, the process proceeds to step 4340. In step 4330, the drag target drive wheel speed Vt is determined as V− (V × target slip ratio S).
At 4340, it is determined that Vt = V-first offset speed Soff.
Here, the first determination speed KS is set so that Soff = KS × S.

That is, as shown in FIG. 7, the drive wheel speed is controlled so as to continue to rotate at a speed smaller than the vehicle speed at least at the first offset speed Soff.

When the drag target drive wheel speed Vt is determined in step 4330 or step 4340, the vehicle body V is compared with the second determination speed KT in step 4350, and if V ≦ KT, step 4360
If V <KT, the process proceeds to step 4370. In step 4360, the drag control start speed Vh = V−V × drag control start slip ratio H is determined, and in step 4370, Vh = V−the second offset speed Hoff is determined. Here, the second determination speed
KT is set so that Hoff = V− (KT × H).

Drag target drive wheel speed Vt and drag control start speed Vh
The calculation formula is different depending on the relative positional relationship of the vehicle speed V with respect to the first determination speed KS or the second determination speed KT. This is because the target drive wheel speed Vt or the drag control start speed Vh is usually [V−V × target slip ratio S] or [V−V ×
Drag control start slip ratio H] is preferable in terms of stable control. However, with only this, the target drive wheel speed Vt or the drag control start speed Vh and the vehicle speed V gradually decrease as the vehicle speed V decreases. The difference becomes small, which may cause difficulties in control and control errors. For this reason,
When the vehicle speed is V <KS or V <KT, the target drive wheel speed Vt or the drag control start speed Vh is set so that the lower limit of the difference is the first offset speed Soff or the second offset speed Hoff.

Therefore, as shown in FIG. 7, when the drive wheel speeds VRR, VRL are at least equal to or less than the second offset speed Hoff with respect to the vehicle speed V, it is determined that the drive wheels 31, 33 have caused an excessive slip. The drag control start determination speed Vh is set so that the drag control for suppressing the drag is started.

The value of the constant during processing is, for example, KS = 50km
/ h, KT = 50km / h.

Further, the drag control target slip ratio S and the drag control start slip ratio H are not fixed values, but the steering angle SA.
Will be changed accordingly. For example, it is set as shown in FIG. In other words, it is set so that the slip ratio is further reduced during the turning as compared with the straight traveling state, and a necessary side force is obtained. Here, the steering angle SA is represented by “0” in a straight traveling state, minus by a left turn, and plus by a right turn. In this way, a stable running is ensured while maintaining the necessary side force at the time of turning.

As shown in FIG. 19, the target slip ratio S and the drag control start slip ratio H are set such that the side force is sufficient. Therefore, the drag control can be started before the vehicle becomes unstable due to excessive engine braking.

In the next steps 4380 and 4390, the left and right driving wheel speed signals VR
A process is performed to remove the vibration generated by the friction between the tire and the road surface from L and VRR. This vibration has a cycle of about 30 to 50 ms in many cases, and is not a component representing the behavior of the vehicle. Therefore, it must be removed when performing highly accurate control. In this embodiment, nozzle removal is performed using a band removal filter that removes only the region of 10 to 30 Hz. Note that, in the case where only the start acceleration is performed, a process of removing all components of 10 Hz or more may be performed.
The left and right driving wheel signals thus obtained are respectively VRLF and VRR.
F, and finally, in step 4395, the left driving wheel acceleration GVRL and the right driving wheel acceleration GVRR are respectively set to the previous values of VRLF and VRRF, VRLFO and VRRFO.
Then, the vehicle speed signal processing is temporarily terminated.

Returning to FIG. 4 again, in the following step 4400, in the slip state determination processing shown in detail in FIG. 8, a processing of setting a flag FTS when an excessive slip has occurred is performed. First, in step 4410, the speed of the left rear wheel (drive wheel) 33
Compare VRLF with the target drive wheel speed Vt for drag, and find that VRLF> Vt
If so, proceed to step 4420. In step 4420, the left rear wheel holding speed XVRL is compared with the left rear wheel speed VRLF. If XVRL = VRLF, the value of the counter CRL is increased by 1 in step 4450. XVRL
な ら ば If it is VRLF, set the value of the left rear wheel speed VRLF to the left rear wheel holding speed XVRL in step 4430 and set the counter CRL in step 4440.
Is set to 1. After steps 4440 and 4450, step 446
At 0, the left drive wheel initial deceleration GRL is cleared, and the flow proceeds to the right drive wheel processing at step 4520. In the processing of steps 4420 to 4460, processing is performed to hold the left rear wheel speed VRLF at the time when the left rear wheel speed VRLF falls below the target driving wheel speed Vt as the left rear wheel holding speed XVRT. Of course, if this processing is repeated at sufficiently short intervals, the left rear wheel holding speed XVRL is equal to the target driving wheel speed Vt, so the target driving wheel speed Vt itself is used without holding the left rear wheel speed VRLF. May be.
The same applies to step 4520 described later.

If it is determined in step 4410 that VRLF ≦ Vt, step 4470
Then, the VRLF is compared with the drag control start determination speed Vh. If VRLF> Vh, the value of the counter CRL is incremented by 1 in step 4480, and then the process proceeds to step 4520.

If VRLF ≦ Vh, the left driving wheel end speed YVRL in step 4490
To the value of the left rear wheel speed VRLF, and in the next step 4500
From the XVRL, YVRL, and CRL, the left driving wheel initial deceleration GRL is obtained as in the following equation.

GRL = (XVRL-YVRL) / CRL Next, the drag speed condition flag FTS is set, and the flow advances to step 4520.

In the processing of steps 4490 to 4510, a processing is performed in which the left rear wheel speed VRLF is further lowered and the left rear wheel speed VRLF when the drag control start determination speed Vh is cut off is held as the left driving wheel end speed YVRL. I have. Of course, if this process is repeated at sufficiently short intervals, the left driving wheel end speed YVRL is equal to the drag control start determination speed Vh, so the left rear wheel speed is bothersome.
Instead of using VRLF, the drag control start determination speed Vh itself may be used. The same applies to step 4520 described later.

In the following step 4520, the same processing as the above-described processing (steps 4410 to 4510) performed for the left rear wheel 33 is performed for the right rear wheel 31 to determine occurrence of slip of the right rear wheel 31, and the right rear wheel at the time of the determination. , That is, the right driving wheel initial deceleration GRR is obtained. Finally, in step 4530, the initial deceleration G
FI is obtained from the left driving wheel initial deceleration GRL and the right driving wheel initial deceleration GRR, and the process is terminated once.

Returning to FIG. 4, after the slip state determination step 4400 in the signal input base processing step 4000, the start and end of the drag control are determined in step 4600. The details are shown in FIG. First, in step 4610, a fail flag FF which is set when it is determined that there is an abnormality in another process (not shown) for determining the presence or absence of an abnormality in the drive system of the throttle valve 7 is determined. Since it is not appropriate to execute the drag control, the drag execution flag FT is reset in step 4660, and the process ends once.

In step 4615 executed when the fail flag FF is reset, if the signal BRK of the brake sensor 43a is on, the operation is inappropriate for the drag control, so that the process proceeds to step 4660 to end the operation. If the signal BRK is off, in step 4620, the accelerator operation amount AA is checked and compared with the operation amount determination value KA (KA = 1.5 degrees in this embodiment). AA
If ≧ KA, accelerator operation amount AA that causes engine braking
Therefore, the process proceeds to step 4660 to end the present process. If AA <KA, it is determined in step 4630 whether or not the drag is being executed by referring to the drag execution flag FT.

When the drag execution flag FT is reset, that is, when the drag control has not been executed until now,
In step 4640, the drag speed condition flag FTS is viewed. If the drag speed condition flag FTS is set here, the drag control condition is satisfied, and step
At 4650, the drag execution flag FT is set, and if the drag speed condition flag FTS is reset, the process skips step 4650 without setting the drag execution flag FT, and terminates this processing once.

If the drag execution flag FT has already been set in step 4630, in step 4670, the target throttle opening TH repeatedly calculated in the throttle control base processing step 6000 described later is compared with the drag target opening THDRG, If TH> THDRG, a target throttle opening TH that is higher than necessary is already set. Therefore, the drag execution flag FT is reset in step 4680, and the process proceeds to step 4690. If TH ≧ THDRG, the drag speed condition flag FTS is reset in step 4690, and the process is temporarily terminated.

Data and flags necessary for drag control are prepared by the above-described signal input base processing step 4000, and then drag control using them is performed in order of step 5000 of FIG. 3, followed by step 6000.

First, FIG. 10 shows the detailed processing contents of the fuel injection base processing step 5000.

First, in step 5100, the intake pipe pressure is
The basic pulse width of the fuel injection pulse is determined from PM and the engine speed Ne, and the engine coolant temperature THW and intake air temperature are determined.
The basic pulse width is corrected from THA and the fuel injection pulse width T
Ask for I. Then, in the next step 5280, the ignition timing St is calculated based on various input signals, and then the present processing is terminated.

By the way, the engine speed Ne used in the above processing is
The opening of the injection valve 15 in accordance with the calculation of the fuel injection pulse width TI determined in the above processing is performed by a general engine rotation interruption (occurring every 30 degrees of the crank angle) shown in FIG. Done. That is, in step 5510, the time interval from the previous interruption is set to T1, then, in step 5520, the engine rotation speed Ne is calculated from the reciprocal of T1, and in step 5530, the injection start timing is determined. , If the fuel injection pulse width T1 is not zero in the judgment of step 5540,
In step 5550, the injector 15 is opened by the fuel injection pulse width T1 to inject fuel into the branch 3c of the intake pipe 3.

The throttle control base processing step 6000 executed after step 5000 will be described with reference to FIG. First, in step 6010, the maximum throttle opening THMAX corresponding to the engine speed Ne is obtained by performing an interpolation calculation on a data table stored in the ROM 50d as illustrated in Table 1.

This is to find a point (THMAX) at which the engine torque saturates with respect to the throttle opening, and to secure the responsiveness of the throttle valve 7 during the closing operation by not opening the throttle valve 7 any more. .

In step 6020, the smaller of the maximum throttle opening THMAX and the target throttle opening THAA corresponding to the accelerator determined according to the accelerator operation amount AA is set to the target throttle opening TH.
And In the next step 6030, the drag execution flag FT is checked. If the drag execution flag FT has been set, the flow proceeds to step 6040, and if the drag execution flag FT has been reset, the flow proceeds to 6050. In step 6050 where the drag control is not performed, the drag start flag FTT by the throttle valve 7 is reset, and then in step 6060 the target throttle opening is set.
TH is the step motor target step number CMD, and step 6
Proceed to 070. Thus, normal throttle opening control is performed.

In step 6040, the drag start flag FTT is checked. If the flag FTT has been reset, it is determined that the process is the first process at the time of executing drag control by the throttle valve 7. First, in step 6100, the current drive wheel torque TW (at the time when slip is determined to occur) is calculated. .

Here, the processing in the drive wheel torque TW calculation step 6100 is shown in FIG.

First, in step 6110, the torque saturating opening Tsut and the zero torque opening Tzero corresponding to the engine speed Ne are set.
Are obtained by interpolation from the map exemplified in Table 2.

In general, the relationship between the throttle opening and the engine torque of a gasoline engine is as shown in FIG. 14, and the throttle opening is zero (fully closed) to a certain opening (torque saturating opening Ts).
Until ut), the torque increases linearly, and the torque saturates at a larger opening (THMAX), and the torque does not increase even if the opening is further increased. Also, when the rotation speed Ne is increased, the inclination of the linear portion becomes smaller,
The throttle opening at which the torque is saturated increases.

Therefore, in step 6130 to be described later, the current drive wheel torque TW is obtained based on the above-described linear relationship between the throttle opening of the gasoline engine and the engine torque.

Therefore, in this embodiment, the zero torque opening Tzero and the torque saturating opening Tsut are determined in advance for each engine rotation speed Ne by an experiment, and the engine rotation speed Ne and the zero torque opening determined according to the experimental result are determined in advance. Tz
The relationship between ero and the torque saturating opening Tsut is stored as a map in the ROM 50d. In step 6110, specifically, the torque saturating opening Tsut and the zero torque opening Tzero are calculated by interpolation from the above-mentioned map according to the engine speed Ne.

Next, in step 6120, the relationship between the current throttle opening TA and the torque saturating opening Tsut is determined. If Tsut> TA, in step 6130, the torque saturating opening Tsut, the zero torque opening Tzero, and the current throttle opening are determined. Engine torque at TA and maximum throttle opening (saturation torque MA
XT) and the current drive wheel torque TW is calculated according to the above-described linear relationship as in the following equation, and the process is temporarily terminated.

TW = (TA−Tzero) · MAXT / (Tsut−Tzero) If Tsut ≦ TA, in step 6140, the current drive wheel torque TW is set to the saturation torque MAXT, and the process is temporarily terminated.

The saturation torque MAXT in the above-described drive wheel torque TW calculation process may be a constant value. However, since the engine torque changes according to the air density, the saturation torque MAXT is set according to the factors (air temperature, atmospheric pressure) that change the air density. The correction may be made.

In FIG. 12 again, when the processing of step 6100 is completed, in step 6200, the target drive described later is used by using the current (at the time of determining that the slip has occurred) drive wheel torque TW obtained in step 6100 as in the following equation. The initial value of the integral control term FI used in the calculation of the torque FX is obtained, and the previous value FIO of the control term is obtained.
Substitute into. FIO ← Kt × TW where Kt is a predetermined coefficient.

After the processing of step 6200 is completed, the drag start flag FTT is set in the following step 6090 to indicate that the first processing of the drag control has been completed, and the flow proceeds to step 6300. If the flag FTT is set in step 6040, the process proceeds to step 6300 by bypassing the above-mentioned steps 6100, 6200, and 6090 without processing. That is, steps 6100, 6200, 60
90 is executed only once immediately after the traction execution flag FT is set.

In step 6300, a target drive torque FX is obtained by a proportional / integral process (PI process). The details are as shown in FIG. First, in step 6310, the target driving wheel speed is Vt, and the difference between the larger of the left rear wheel speed VRLF and the right rear wheel speed VRRF obtained in the vehicle body signal processing step 4300 is obtained, and the difference is set as the driving wheel speed deviation DV. . In step 6320, a deviation DV is applied to the proportional gain KFP in order to obtain the proportional control term FP. Step 6330
In order to obtain the integral control term F1, the product of the integral gain KFI and the deviation DV is added to the previous value FIO of the integral control term F1. In step 6340, the target drive torque FX is calculated by adding FP and FI.
In step 6350, the integral control term FI obtained in step 6330 is set to the previous value FIO, and finally, a determination is made in step 6360 so that the target drive torque FX obtained in previous step 6340 does not become a positive value. If so, the target driving torque FX is set to 0 in step 6370 to prevent the vehicle from shifting from deceleration to acceleration in the reverse state at the time of engine braking, and this flowchart is temporarily ended.

Subsequently, returning to FIG. 12, in step 6400, the target drag opening THDRG is calculated from the target drive torque FX obtained in step 6300 described above. In this calculation process as well, the drag target opening THDRG is calculated based on the process shown in FIG. 16 by utilizing the linearity between the engine torque and the throttle opening shown in FIG. First, in step 6410, the torque saturating opening Tsut and the zero torque Tzero are obtained based on the engine speed Ne in the same manner as in step 6110 of the drive wheel torque TW calculation step 6100 in FIG. At step 6420,
The gear position G based on the output signal from the gear position sensor 27a
P is determined, and the gear ratio TSHFT is determined from that position. Steps
For 6430, drive wheel speed (right rear wheel speed VRRF, left rear wheel speed VRL
F) and the gear ratio of the differential gear 29
The output rotation speed on the output side of 7 is obtained, and the torque conversion rate RTOR of the torque converter 25 is obtained from the ratio of this output rotation speed to the engine rotation speed Ne. Then, in step 6440, the target drive torque FX is first-order-converted by Tsut, Tzero obtained in step 6410 described above, and the drag target opening THDRG is determined by correcting with TSHFT, RTOR obtained in steps 6420, 6430. Is temporarily terminated.

Returning to FIG. 12, after the processing of step 6400 is completed, the flow proceeds to step 6095. In step 6095, the calculated target opening THDR
G is set in the target step CMD, and the flow advances to step 6070.
In step 6070, the target step number CMD is compared with the actual step number POS indicating the current position of the rotor of the step motor 9 used for driving the step motor 9, and if they are different, a motor drive interrupt is started in step 6080. After this processing is performed, the present processing is temporarily terminated, and if they match, the processing is bypassed without performing step 6080, and the present processing is temporarily terminated.

In the motor drive interruption (step 6080), as shown in FIG. 17, first, in step 6081, the excitation phase is updated according to the previous setting, and then in step 6082, the actual step number PO is updated.
S is incremented or decremented according to the update of the excitation phase. That is, the rotor position and the actual number of steps PO
The actual step number POS is increased or decreased by “1” so as to match S. Goal step CM in step 6083
D is compared with the actual number of steps POS, and if they match, in step 6084, the motor drive interrupt prohibition process is performed, and the rotation of the step motor 9 is stopped. If they do not match, steps 6085 and 6
In step 086, the next excitation phase and the interrupt time are set, and the excitation phase is updated again, and this process is temporarily terminated.

In this embodiment, the throttle valve 7 is controlled in the opening direction when the slip of the drive wheels 31 and 33 is likely to be excessive due to the engine brake, and the output torque of the engine 1 increases. Since the negative torque is suitably reduced and maintained at an appropriate slip ratio, stability of the vehicle traveling is ensured. Further, since the drag control target slip ratio S and the drag control start slip ratio H are changed in accordance with the steering angle SA, the slip ratio can be further reduced during turning as compared with the straight traveling state, and the side force is reduced. Can be suppressed. Therefore, even if the engine brake and the turn overlap, the required side force is maintained and stable running is ensured. As a device, drag control can be realized by using a conventional traction control device as it is and simply changing the program in software.

In step 4395 of FIG. 6, the driving wheel accelerations GVRL, GVR
R is obtained, and the drive wheel decelerations GRL, GRR, and GFI are obtained in steps 4500, 4520, and 4530 in FIG. 8, but this is used for other processes (not shown), and the drive wheel accelerations GVRL, GVRR, and Driving wheel deceleration GRL, GRR, GFI
This is a process that does not need to be executed if the drag control is limited to the present embodiment. In particular, when the slip state determination process of FIG. 8 is simplified, the process becomes as shown in FIG. That is, both rear wheel speeds
If both VRLF and VRRF are greater than the drag control start speed Vh (steps 7010 and 7030), no action is taken assuming that excessive slip due to engine braking has not occurred, but the left rear wheel speed VRLF and the right rear wheel speed VRRF If either of them is lower than the drag control start speed Vh (steps 7010 and 703)
0), set the drag speed condition flag FTS (step 70)
20,7040) and end once. The subsequent processing is as described above.

Note that the drive wheel speeds VRLF, GLF, GVRR, and the drive wheel deceleration GRL, GRR, GFI increase from the drive wheel speed VRLF,
The VRRF or slip state may be predicted, and the drag control may be executed early.

In the above embodiment, the rear wheels 31, 33 correspond to the drive wheels M1, the engine 1 corresponds to the power generating means M2, the throttle valve 7 corresponds to the power adjusting means M3, and the steering angle sensor 39a corresponds to the turning state detecting means. And the ECU 50 has the negative torque detecting means M5,
Variable control means M6, limiting means M7 and slip state detecting means
Step S4600, which corresponds to M8 and is executed by ECU 50
Mainly corresponds to the processing as the negative torque detecting means M5, the throttle control base processing in step S6000 mainly corresponds to the processing as the variable control means M6, and steps S6360 and 6370 mainly correspond to the processing as the limiting means M7. Step S4400 mainly corresponds to the processing as the slip state detecting means M8.

In the above embodiment, the output of the engine is controlled by the throttle valve. However, the output may be controlled by adjusting the back pressure of the engine 1 using an exhaust throttle valve instead of the throttle valve. In addition, the engine output control may be executed by ignition timing control. In the case of a diesel engine, the engine output control may be executed by controlling the fuel injection amount or the injection timing.

In addition to internal combustion engines, for example, in electric vehicles and the like,
Drag control can be performed by controlling the amount of supplied power, which is also one embodiment of the present invention.

In the above embodiment, the negative torque detecting means M5 determines that a negative torque is generated from the degree of the accelerator operation amount (step 4620). However, when the opening of the throttle valve 7 is equal to or less than the predetermined opening, the negative torque is detected. It may be determined that a torque is generated. In addition, since the torsion of the output shaft of the engine 1 is reversed when the engine is braked as compared to the normal running, the generation of a negative torque is detected from the reversal of the torsion. The determination condition for starting the drag control may be used.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a basic configuration of the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of a vehicle slip control device of the present invention,
FIG. 3 is a schematic flowchart of the whole drag control executed by the ECU, FIG. 4 is a detailed flowchart of the signal input base processing, FIG. 5 is a flowchart of the vehicle speed interrupt processing, and FIG. 6 is a detailed flowchart of the vehicle speed signal processing. ,
FIG. 7 is a graph showing a setting state of a drag target drive wheel speed Vt and a drag control start speed Vh with respect to a vehicle speed V.
The figure shows the detailed flowchart of the slip state determination process, ninth
FIG. 10 is a detailed flowchart of the drag control start and end determination processing, FIG. 10 is a detailed flowchart of fuel injection base processing, FIG. 11 is a flowchart of engine rotation interrupt processing, FIG. 12 is a detailed flowchart of throttle control base processing, FIG. 13 is a detailed flowchart of the drive wheel torque TW calculation process, FIG. 14 is a graph showing a relationship between the throttle opening degree and the engine torque according to the engine rotation speed Ne, and FIG. 15 is a detail of the target drive torque FX calculation process. Flowchart, FIG. 16 is a detailed flowchart of a target opening degree TDRRG during drag calculation, FIG. 17 is a detailed flowchart of a motor drive interruption process, and FIG. 18 is a steering angle SA, a target slip ratio S, and a drag control start slip ratio H. 19 is a graph showing the relationship between the slip ratio and the braking force and the side force. FIG. 0 is an explanatory diagram of the steering angle SA, and FIG. 21 is a flowchart of another example of the slip state determination processing. M1 ... Drive wheel, M2 ... Power generation means M3 ... Power adjustment means M4 ... Turn state detection means M5 ... Negative torque detection means M6 ... Variable control means, M7 ... Limiting means, M8 ... Slip state Detecting means, 1 ... engine, 7 ... throttle valve,
31,33… rear wheel (drive wheel), 39a… steering angle sensor, 50…
ECU

Continued on the front page (72) Inventor Mitsuo Hara 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture, Japan Denso Co., Ltd. ) Inventor ▲ Taka ▼ Mitsunori Ochi 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-62-295762 (JP, A) JP-A-62-23831 (JP, A) JP-A-1-87844 (JP, A) JP-A-63-31859 (JP, A) JP-A-63-31863 (JP, A) JP-A-62-153533 (JP, A)

Claims (3)

(57) [Claims] 1. An accelerator pedal which is depressed and adjusted by an occupant, a signal converting means for converting an occupant's depressing operation state with respect to the accelerator pedal into an electric signal, mounted on a vehicle, and running the vehicle via driving wheels. Power generation means for generating power for causing the power generation means, power adjustment means for adjusting the power generation amount of the power generation means according to the electrical signal converted by the signal conversion means, Turning state detecting means for detecting; negative torque detecting means for detecting that the power generating means is applying a negative torque in the deceleration direction of the vehicle to the drive wheels; If the degree of the turning state of the vehicle, which is the detection result of the turning state detecting means, is greater, the amount of adjustment of the power generation amount A variable control unit that executes the power adjustment unit so as to control the negative torque, which is a deceleration direction of the vehicle, to reduce the amount of power generation, and the variable control unit Vehicle slip control comprising: limiting means for limiting the power applied to the drive wheels to not substantially become positive torque when the power generation amount adjustment amount variable control is performed. apparatus. 2. The vehicle slip control device according to claim 1, wherein the variable control means executes the power adjustment means.
While controlling the slip state of the drive wheels detected by the slip state detection means to be a predetermined reference slip state, the greater the degree of the turning state of the vehicle, the greater the
A vehicle slip control device, wherein the reference slip state is set to be small so that the negative torque in the deceleration direction of the vehicle becomes small. 3. A power generating means mounted on a vehicle for generating power for driving the vehicle via driving wheels; a power adjusting means for adjusting a power generation amount of the power generating means; A slip state detecting means for detecting a slip state of the drive wheel during acceleration, a traction control means for suppressing an acceleration slip state of the drive wheel according to a detection result of the slip state detecting means, and detecting a turning state of the vehicle Turning state detecting means; negative torque detecting means for detecting that the power generating means is applying a negative torque in the deceleration direction of the vehicle to the drive wheels; and negative torque when the traction control means is executed. When the negative torque is detected by the detecting means,
Variable control means for executing the power adjustment means to vary the adjustment amount of the power generation amount in accordance with the degree of the turning state of the vehicle, which is a detection result of the turning state detection means, Vehicle slip control device.