JPH02191833A - Vehicle slip control device - Google Patents

Abstract

PURPOSE:To suppress an excessive slip by adjusting a power adjusting means controlling a drive wheel for its detected slip condition to a predetermined condition when the drive wheel is detected for its negative torque generated. CONSTITUTION:Power from a power generating means M2 is transmitted to a drive wheel M1 running a vehicle. Reversely when the power is decreased, negative torque is generated in the drive wheel M1 by various losses in the power generating means M2, here it generates an engine brake providing possibility of generating an excessive slip on a low friction road. Accordingly, when the negative torque is detected in a detecting means M5, a slip control means M6 adjusts a power adjusting means M3 controlling power generated by the power generating means M2 and a slip condition of the drive wheel M1 to a predetermined condition. Thus stabilization can be contrived of the running vehicle by suppressing the excessive slip caused by the engine brake.

Description

[Detailed Description of the Invention] Purpose of the Invention [Industrial Application Field] The present invention prevents a vehicle from slipping on a road surface with a low coefficient of friction such as an icy road when engine braking is applied.
This relates to so-called engine drag control that attempts to achieve good steering performance.

[Prior Art] In order to prevent the driving wheels from spinning when the vehicle starts rapidly, the slip ratio S determined from the vehicle running speed vb determined from the driven wheels and the driving wheel speed Vd is set within a predetermined range. A device for controlling the opening degree of a throttle valve (traction control) is known (Japanese Unexamined Patent Application Publication No. 62-1
21839).

Another similar technology is to control engine output so that the lateral acceleration of the vehicle does not exceed a predetermined limit value, in order to prevent the drive wheels from spinning when the vehicle turns, reducing the side force and causing the vehicle to spin. The device is also known (Japanese Unexamined Patent Application Publication No. 6
2-10437).

In both of these technologies, in order to prevent the drive wheels from sliding due to excessive engine output, an electric actuator is used to reduce the opening degree of the throttle valve, thereby reducing the engine output.

[Problems to be Solved by the Invention] However, on the contrary, no countermeasures have been taken for the inconvenience caused by too little engine output.

In other words, when the driving wheels slip due to negative torque from the engine on a low-friction road such as an icy road, so-called engine braking, reducing the engine output as with conventional traction control will cause the engine braking to act on the driving wheels even more. This resulted in severe slippage and could not contribute to the stability of vehicle running.

[Objective] An object of the present invention is to suppress slips caused by engine braking and to ensure vehicle stability.

Structure of the Invention [Means for Solving the Problems] The vehicle slip control 'eEi device of the present invention is mounted on a vehicle, as illustrated in the basic configuration diagram of FIG. A power generating means M2 that generates power for running, a power adjusting means M3 that adjusts the amount of power generated by the power generating means M2, a slumber state detecting means M4 of the driving wheel M1, and a power generating means M2. negative torque detecting means M5 for detecting that the negative torque is being applied to the drive wheel M1; and when negative torque is detected by the negative torque detecting means M5, adjusting the power adjusting means M3; and a slip control means M6 for controlling the slip state of the drive wheel M1 detected by the slip state detection means M4 to a predetermined state.
It is characterized by having the following.

[Function] The power generated by the power generating means M2 is transmitted to the driving wheels M1 to make the vehicle run. However, if the power is reduced, the driving wheels will be damaged due to various losses in the power generating means M2. Negative torque is generated in M1. At this time, the power generating means M2 produces an effect of decelerating the vehicle, so-called engine braking. At this time, there is a risk that excessive slip may occur, especially on low-friction roads.

Therefore, when negative torque is detected by the negative torque detection means M5, the slip control means M6 adjusts the power adjustment means M3 to control the power generated by the power generation means M2, and controls the drive wheel M1. control the sleep state of the device to a predetermined state. By doing so, excessive slip caused by engine braking is suppressed, and the running vehicle becomes stable.

Embodiment FIG. 2 is a schematic diagram showing an embodiment of the vehicle slip control device of the present invention.

An internal combustion engine (hereinafter simply referred to as engine) 1 is a spark ignition four-cylinder gasoline engine, and is installed in a vehicle. An intake pipe 3 and an exhaust pipe 5 are connected to the engine 1. The intake pipe 3 is connected to an air cleaner (not shown)! It consists of two collecting parts 3a, a surge tank 3b connected to the collecting part 3a, and a branch part 3c branching off from the surge tank 3b corresponding to each cylinder of the engine 1.

A throttle valve 7 for adjusting the amount of air taken into the engine 1 and the output generated by the engine 1 is provided in the gathering portion 3a. The valve shaft of the throttle valve 7 is connected to a step motor 9 that adjusts the opening degree of the throttle valve 7 and a throttle sensor 11 that detects the opening degree of the throttle valve 7.

Note that the step motor 9 is provided with a motor fully closed sensor 9a that detects the fully closed position of the motor 9.

Further, an intake air temperature sensor 13 for detecting intake air temperature is provided at a position upstream of the throttle valve 7 in the gathering portion 3a.

The surge tank 3b is provided with an intake pipe pressure sensor 14 that detects the pressure inside the intake pipe 3, and each branch part 3c
includes an electromagnetic fuel injection valve 1 that injects fuel into the branch portion 3c.
5 are provided respectively.

The engine 1 is also provided with spark plugs 17 for igniting the intake air-fuel mixture corresponding to each cylinder. This spark plug 17 is connected to a distributor 19 via a high voltage cord, and this distributor 1
9 is electrically connected to the igniter 21. The distributor 19 is provided with a rotation sensor 19a that outputs a signal synchronized with engine rotation.

Furthermore, the engine 1 is provided with a water temperature sensor 23 that detects the temperature of the cooling water that cools the engine 1.

The power generated by the engine 1 is transferred to the torque converter 25.
Shift $27. The right rear wheel 31 serves as a driving wheel via a differential gear 29 and the like. The signal is transmitted to the left rear wheel 33. The transmission 27 is equipped with a gear position sensor 27a that outputs a gear position signal corresponding to the gear position, and also includes a right rear wheel 31, a left rear wheel 33, a right front wheel 35 degrees, a driven wheel, and a left front wheel. 37 are wheel speed sensors 31a, 33a, and 35a for detecting wheel rotational speeds, respectively.

37a is provided.

The steering angle sensor 39a detects the steering angle SA of the front wheels 35, 37, which changes with three steering operations.

As shown in Fig. 20, the steering angle SA is the turning center CC of the vehicle.
It is represented by the angle between a tangent Ld on the center point FC of a circle centered on , and passing through the center point FC between the right front wheel 35 and the left front wheel 37, and the vehicle direction Md.

An accelerator operation amount sensor 41a that outputs a signal corresponding to the operation amount of each of the above-mentioned sensors and the accelerator pedal 41, an accelerator fully closed sensor 41b that detects when the accelerator pedal 41 is released and the accelerator is fully closed, and a brake. Signals from the brake sensor 43a that turn on when the pedal 43 is depressed are input to an electronic control unit (ECU) 50, and the ECU 3O controls the step motor 9. based on these signals. Injection valve 15. A signal for driving the igniter 21 is output.

The ECU 3O is a CPU 50a that executes various calculations;
The RAM 50b temporarily stores data required for calculations by the CPU 50a, which is necessary for calculations by the CPU 50a, is updated sequentially while the engine is running, and is retained even after the vehicle key switch 51 is turned off. A RAM 50c stores necessary data, and a ROM 50d stores constants used in calculations by the CPU 30a.

A human-powered boat 50e for manually inputting the signals of each of the above sensors
and a timer 50 that measures the time of the person counter 50f9.
g9 An interrupt control unit 50h that interrupts the CPO 50a according to the data contents of the human power counter 50f and the timer 50g, and the steering motor 9. Injection valve 15. an output circuit 50i that outputs a signal for driving the igniter 21;
Pass lines 501.50j and 50 serve as data transmission paths between the ECU components. A power supply circuit 50m that is connected to the battery 53 via the key switch 51 and supplies power to each element other than the RAM 50c, and a power supply circuit 50n that is directly connected to the battery 53 and supplies power to the RAM 50c. It is equipped with Below is the above ECU3
The drag control process executed in O will be explained using a flowchart.

Figure 3 is a schematic flowchart of the program.
First, as an initialization process, step 2000.3000
is executed. That is, when the power is turned on, the system is started by resetting, and each control variable is initialized at step 2000. Further, in step 30QO, the operating position of the actuator is initialized and an operation check known as a primary check is performed.

In the next step 4000, as signal human power-based processing,
Human power of various digital and analog signals.

It determines the vehicle running state, creates data and sets flags corresponding to the determination. Then step 50
In step 00, the fuel injection amount for the fuel injection execution process is calculated as the fuel injection base process, and the process proceeds to step 6000.
Then, the target throttle opening degree is calculated as throttle control pace processing. After step 6000 is completed, the process moves to a state of waiting for a scheduled interrupt. Scheduled interrupts are done by STEP 2000.
Then, set the interrupt interval time (for example, 1
0m5), and after that, it will occur every 10m5, and ST4000 or less will be activated.

Next, details of the signal human power-based processing in step 4000 will be explained with reference to FIG. In this process, first the chip 4100
and the analog signal intake air temperature THA.

Accelerator operation amount AA, intake pipe pressure PM, cooling water temperature THW
, throttle distance T, opening, steering angle SA, and gear position CP, and digital signals such as accelerator fully closed signal IDL, motor fully closed signal MOF, and brake depression signal BRK are manually input using step knob 4200.

Next, in step 4300, vehicle speed signal processing is performed, but here, as shown in FIG. ]
Although this process is shown, the same applies to other wheel speeds, so illustrations are omitted. ) The right front wheel speed VFR, the left front wheel speed VFL, the right rear wheel speed VRR, the left rear wheel speed V obtained by the vehicle speed interrupt processing that is synchronized with the wheel speed as shown in
From RL, the target drive wheel speed Vt, drag control start speed vh, etc. necessary for control are calculated.

The details of step 4300 are as shown in FIG.
, the rotational speed VFL of the left front wheel 37 and the steering angle SA, the vehicle speed V at the center between the right rear wheel 31 and the left rear wheel 33, that is, the position of the differential gear 29, is determined from the following equation.

V= [cosSA+ (B/2L) 5in
SA] [(VFR+VFL)/2] where rLJ is the vehicle's wheel base and rBJ is the rear wheel 31
．． 33 tread width is shown.

Next, in step 4320, the vehicle speed V and the first judgment speed 1 (S are compared, and if V≧KS, the process proceeds to step 4330, and V<K
If S, the process advances to step 4340.

In step 4330, the drag target drive wheel speed Vt)
S=V-(VX target rate S), and in step 4340, Vt=V-first offset speed 5off.
It is determined that Incidentally, here, the first judgment speed KS is 5off=K
It is set to be SXS.

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

After determining the drag target drive wheel speed Vt in step 4330 or step 4340, step 4
At 350, the vehicle speed V and the second judgment speed KT are compared, and V≦KT.
If so, go to step 4360; if V(KT, step 4)
The process proceeds to step 370, and in step 4360, drag control start speed vh=v-v×drag control start slip rate H is determined, and in step 4370, vh=v−second offset speed Hoff is determined. In addition, here, the second judgment speed KT
is set so that Hoff=V-(KTXH).

The drag target drive wheel speed Vt and drag control start speed vh have different calculation formulas depending on the relative positional relationship of the vehicle speed V with respect to the first judgment speed KS or the second judgment speed KT, respectively. This means that the target drive wheel speed Vt or drag control start speed vh is usually set by [CV-Vx Target Slip Rate S] or [V-■ x Drag Control Start Slip Rate H] if the vehicle speed V is sufficient. However, if this is done alone, the difference between the target drive wheel speed Vt or drag control start speed Vh and the vehicle speed will gradually become smaller as the vehicle speed V decreases, causing control difficulties and Control errors may occur. Therefore, if the vehicle speed V<KS or V(KT), the lower limit of the difference is the first offset speed 5off
Alternatively, the target drive shaft speed Vt or the drag control start speed Vh is set to be the second offset speed Hoff.

Therefore, as shown in FIG. 7, the driving wheel speed VRR.

When the VRL becomes at least the second offset speed f-(off) with respect to the vehicle speed V, the driving wheels 31.33
The drag control start determination speed vh is set so that it is determined that an excessive slip has occurred, and drag control to suppress the slip is started.

In addition, as an example, the value of the constant during the above processing is S=0.
02 (2%), Soff=1km/h, KS=50k
m/h, H=0.06 (6%), Hoff=3k
m/h, K T = 50km/h.

Here, the target slip rate S and the drag control start slip rate H are set to a slip rate that provides sufficient side force, as shown in FIG. Therefore, drag control can be started before vehicle running becomes unstable due to excessive engine braking.

In the next step 43B0.4390, processing is performed to remove vibrations caused by friction between the tires and the road surface from the left and right drive wheel speed signals VRL and VRR.

This vibration is often about 30 to 50 m5 per lap, and since it is not a component representing vehicle behavior, it must be removed if highly accurate control is to be performed. In this example, 10 to 30
Noise is removed using a band-removal filter that excludes only the H2 region. In addition, if it is applicable only when starting and accelerating, set 1.
A process may be performed to remove all components of 0H2 or higher. The left and right driving wheel signals obtained in this way are respectively VRLF,
Finally, in step 4395, the left driving wheel acceleration GVRL and the right driving wheel acceleration GVRR are set to VRLF.
, VRRFCD and the previous values VRLFO and VRRFO are calculated, and the vehicle speed signal processing is temporarily terminated.

Returning to Fig. 4 again, in the subsequent STEP 4400, the 8th
In the slumber state determination process, the details of which are shown in the figure, a flag FTS is set if excessive slumber occurs. First, in step 4410, the speed VRLF of the left rear wheel (drive wheel) 33 and the drag target drive wheel speed V are determined.
t, and if VRLF>Vt, step 442
Go to 0. In Ste-Nbu 4420, left rear wheel holding speed XV
Compare RL and left rear wheel speed VRLF, XVRL=VR
If it is LF, the counter CRL is incremented by 1 in step 4450. If XVRL≠VRLF, step 4430
In step 4440, the value of the left rear wheel speed VRLF is set to the left rear wheel holding speed XVRL, and the value of the counter CRL is set to 1 in step 4440. After step 4440.4450, step 44
At step 60, the left drive wheel initial deceleration GRL is cleared, and the process moves to right drive wheel processing at step 4520. This Ste-Nbu442
The processes from 0 to 4460 are executed to hold the left rear wheel speed VRLF as the left rear wheel holding speed XVRL when the left rear wheel speed VRLF decreases and falls below the target driving wheel speed Vt. Of course, if this process is repeated at sufficiently short intervals, the left rear wheel holding speed XVRL will be equal to the target drive wheel speed Vt.
Therefore, the target drive wheel speed Vt itself may be used without taking the trouble to reserve the left rear wheel speed VRLF. The same applies to step 4520, which will be described later.

If it is determined in step 4410 that VRLF≦Vt, the process proceeds to step 4470, where VRLF is compared with the drag control start judgment speed vh, and if VRLF>vh, the step 4480 increments the counter CRL by 1, and then step 4470 is performed. Proceed to 4520.

If VRLF≦vh, the step 4490 sets the left rear wheel speed VRLF to the left drive wheel terminal speed YVRL, and the next step 4500 sets the value of the left rear wheel speed VRLF.

The left driving wheel initial deceleration GRL is determined from YVRL and CRL as shown in the formula below.

GRL= (XVRL-YVRL)/CRL Next, set the dragging speed condition flag FTS and step 45
Proceed to 20.

The processing in steps 4490 to 4510 is performed when the left rear wheel speed VRLF further decreases and the drag control start judgment speed vh
The left rear wheel speed VRLF when turning off is the left driving wheel terminal speed Y
Processing to hold it as a VRL is being executed. Of course, if this process is repeated at sufficiently short intervals, the left driving wheel terminal speed YvRL is equal to the drag control start judgment speed vh, so instead of using the left rear wheel speed VRLF, the drag control start judgment speed vh itself is used. May be used. The same applies to the stem 4520 described later.

In the following step 4520, the same process as the above process (steps 4410 to 4510) performed for the left rear wheel 33 is performed for the right rear wheel 31 to determine whether the right rear wheel 31 has slipped, and the right rear wheel at the time of the determination is , that is, the initial deceleration GRR of the right driving wheel. Finally, Ste.
In step 4530, the period deceleration GFI is determined from the left drive wheel initial deceleration GRL and the right drive shaft initial deceleration GRR, and the process is temporarily terminated.

Returning to FIG. 4, in the signal human power based processing step 4000, after the slip state determination step 4400, the start and end of drag control is determined in step 4600.

The details are shown in FIG. First, in step 4610, check the fail flag FF that is set when it is determined that there is an abnormality in a separate process (not shown) that determines whether there is an abnormality in the drive system of the throttle valve 7, etc. For example, since it is not appropriate to execute drag control in the event of an abnormality, the drag execution flag FT is reset in step 4660 and the process is temporarily terminated.

In step 4615, which is executed when the fail flag FF is reset, if the signal BRK of the brake sensor 43a is on, the operation state is inappropriate for drag control, so the process proceeds to step 4660 to end. If the signal BRK is off, in step 4620, the accelerator operation amount AA is looked at and compared with the operation amount determination rfKA (KA=1.degree. 5 degrees in this embodiment). If AA≧KA, the accelerator operation amount AA does not cause engine braking, so the process proceeds to step 4660 and ends this process once.

If AA<KA, then in step 4630 the drag execution flag FT is checked to determine whether or not drag is being executed.

When the drag execution flag FT is reset, that is, when drag control has not been executed until now,
At step 4640, the drag speed condition flag F'I is
' Look at S. If the drag speed condition flag FTS is set here, it means that the conditions for drag control are complete, and the drag execution flag FT is set in step 4 50, and if the drag speed condition flag FTS is reset, the drag control conditions are set. Step 4650 is bypassed without setting the execution flag FT, and the process is temporarily ended.

If the dragging execution flag FT has already been set in step 4630, then in step 4670, the target throttle opening TH repeatedly calculated in throttle control base processing step 6000, which will be described later, is compared with the target opening during dragging THDRG. If it is TH) T HD RG, the target throttle opening TH that is higher than the required value has already been set, so the drag execution flag FT is reset in step 4680 and the process proceeds to step 4690. If ≧THDRG, the drag speed condition flag FTS is reset in step 4690, and this processing is temporarily ended.

Data and flags necessary for drag control are prepared by the above signal human power-based processing step 4000, and then drag control using them is performed in step 5000 in FIG.
, followed by step 6000.

First, Fig. 10 shows the fuel injection base processing step 500.
Detailed processing contents of 0 are shown.

First, in step 5100, the basic pulse width of the fuel injection pulse is determined from the intake pipe pressure PM and the engine rotational speed Ne, and then the engine cooling water temperature THW
, the basic pulse width is corrected from the intake air temperature THA to determine the fuel injection pulse width TI. And next step 52
At 80, the ignition time St is calculated based on various human input signals, and then the process ends.

By the way, the engine rotation speed Ne used in the above process
The fuel injection pulse width TT determined by the calculation and the above processing
The valve opening process of the injection valve 15 according to the following is shown in FIG.
This is done by a direct engine rotation interruption (occurs at a crank angle of 30 degrees).

That is, the time interval from the previous interrupt is set to T1 in step 5510, and then T1 is set in step 5520.
Calculate the engine rotation speed Ne from the reciprocal of
The injection start timing is determined in 530, and when the injection start timing is reached, if the fuel injection pulse width TI is not zero as determined in step 5540, the injection valve 15 is opened by the fuel injection pulse width TI in step 5550. The fuel is injected into the branch portion 3C of the intake pipe 3.

The throttle control-based processing step 6000 executed after step 5000 will be explained based on FIG. 12. First, in step 6010, the maximum throttle opening THMAX corresponding to the engine speed Ne is determined by interpolating the data table stored in the ROM 50d as shown in Table 1.

Table 1 This is to find the point (THMAX) at which the engine torque is saturated with respect to the throttle opening, and beyond that the throttle valve 7
This is to ensure responsiveness of the throttle valve 7 during the valve closing operation by preventing the throttle valve from opening.

In step 6020, this maximum throttle opening THMA
The smaller of X and the target throttle opening THAA corresponding to the accelerator determined according to the accelerator operation amount AA is set as the target throttle opening TH. In the next step 6030, the drag execution flag FT is checked and the drag execution flag FT is checked.
If it has been set, the process advances to step 6040, and if it has been reset, the process advances to 6050. In step 6050, which is performed under the condition that drag control is not executed, the drag start flag FTT by the throttle valve 7 is reset, and then in step 6060, the target throttle opening TH is set as the step motor target step number CMD, and step 6
Proceed to 070. In this way, normal throttle opening control is performed.

In step 6040, if the drag start flag FTT is adjusted, it is determined that this is the first processing when executing drag control by the throttle valve 7, and first step 610
0, the current drive wheel torque TW (at the time when it is determined that slip has occurred) is calculated.

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

First, in step 6110, the torque saturation opening degree Tsut and the zero torque opening degree 'l'2ero corresponding to the engine rotational speed Ne are determined by interpolation from the map illustrated in Table 2.

Table 2 In general, the relationship between the throttle opening and engine torque of a gasoline engine is as shown in Figure 14, from the throttle opening field (full open) to a certain opening (torque saturation opening T
The torque increases linearly up to (THMAX), and the torque reaches saturation at an opening (THMAX) larger than that, and no matter how much the opening is increased, the torque will no longer increase. Furthermore, when the rotational speed Ne is increased, the slope of the linear portion becomes smaller, and the throttle opening at which the torque is saturated becomes larger.

Therefore, in step 6130, which will be described later, the current drive wheel torque TW is determined every time based on the relationship between the linear portion of the throttle opening of the gasoline engine and the engine torque.

Therefore, in this embodiment, the engine rotation speed Nei, zero torque opening Tzero, and torque saturation opening Tsut are determined in advance through experiments, and the engine rotation speed Ne and zero torque opening T are determined according to the experimental results. 2ero and torque saturation opening TS
The relationship with ut is stored as a map in R0M50d. Then, in step 6110, specifically, the torque saturation opening degree Tsut is determined according to the engine rotation speed Ne.
and the zero torque opening degree Tzero are determined by interpolation calculation from the above map.

Next, in step 6120, the relationship between the current throttle opening TA and the torque saturation opening Tsut is determined, and T
sut> T A, in step 6130, the torque saturation opening Tsut and the zero torque opening T2er are determined.
0, the current throttle opening TA, and the engine torque at the maximum throttle opening (saturation torque MAXT), calculate the current driving wheel torque TW according to the above-mentioned linear relationship as shown in the formula below, and temporarily end this process. do.

TW= (TA-T2ero) ◆MAXT/ (T
If Tsut≦TA, the current drive wheel torque TW is set as the saturation torque MAXT in step 6140, and the process is temporarily terminated.

Note that the saturation torque MAXT in the driving wheel torque TW calculation process described above may be a constant value, but since the engine torque changes depending on the air density, the saturation torque MAXT may be set according to the factors that change the air density (air temperature, atmospheric pressure). It may be corrected.

Referring again to FIG. 12, when the processing of step 6100 is finished, in step 6200, the current value obtained in step 6100 (the point in time when it is determined that a slip has occurred) is determined as shown in the following formula.
Using the driving wheel torque TW, find the period value of the integral control term Fl used in calculating the target driving torque FX, which will be described later.
Substitute the previous value FIO of the control term.

FIO←KtXTW Here, r<t is a predetermined coefficient.

After completing the process of step 6200, the following step 60
At 90, set the drag start flag FTT and start drag.
It is noted that the first processing control process has been completed, and the process advances to step 6300. Also, in step 6040, the flag F
If TT is set, step 6100. above.
Detour without processing 6200.6090 and proceed to step 63
Go to 00.

In other words, steps 6100, 6200, and 6090 are executed only once immediately after the traction execution flag FT is set.

In step 6300, target drive torque FX is determined by proportional/integral processing (PI processing). The details are as shown in FIG. First, in step 6310, the difference between the target driving wheel speed Vt and the larger one of the left rear wheel speed VRLF and right rear wheel speed VRRF, which were obtained by the vehicle body signal processing step 4300, is determined, and the driving wheel speed deviation DV is calculated. do. Step 6
At 320, the proportional gain KFP is multiplied by the deviation DV in order to obtain the proportional control term FP. Step 6330 adds the product of the integral gain KFI and the deviation DV to the previous value FIO of the integral control term Fl in order to obtain the integral control term FI.

In step 6340, the target drive torque FX is calculated by adding FP and FI, and in step 6350
The integral control term F
If X≧O, the target drive torque FX is set in step 6370.
is set to 0 to prevent the vehicle from shifting from deceleration to acceleration during engine braking, and this flowchart is temporarily terminated.

Subsequently, returning to FIG. 12, in step 6400, the drag target opening degree THDRG is calculated from the target drive torque PX found in step 6300 described above. This calculation process also uses the linearity between the engine torque and the throttle opening shown in FIG. 14 to calculate the drag target opening THDRG based on the process shown in FIG. 16. First, in step 6410, the torque saturation opening degree Tsut and the zero torque T zero are determined based on the engine rotational speed Ne in the same way as step 6110 of the driving wheel torque TW calculation step 6100 in FIG. Step 642
0, the gear position CP is determined based on the output signal from the gear position sensor 27a, and the gear ratio TSHFT is calculated from that position.
seek. In step 643o, the output rotation speed on the output side of the transmission 27 is determined from the drive wheel speed (right rear wheel speed VRRF, left rear wheel speed V RL F) and the gear ratio of the differential gear 29, and this output rotation speed and engine rotation are determined. The torque conversion rate RTOR of the torque converter 25 is determined from the ratio with the speed Ne. Then, in step 6440, T sut and T zer obtained in step 6410 described above are calculated.
TSHFT obtained in steps 6420 and 6430 while linearly converting the target drive torque FX using o.

The drag target opening degree THDRG is determined by correction using RTOR, and this processing is temporarily terminated.

Returning to FIG. 12, after completing the process at step 6400,
Proceed to step 6095. In step 6095, the obtained target opening degree T r (D RG is set to the target step CMD, and the process proceeds to step 6070.

In step 6070, the target number of steps CMD is compared with the actual number of steps PO8 indicating the current position of the rotor of the step motor 9 used when driving the step motor 9.
If the two are different, the process starts the motor drive interrupt in step 6080 and then ends this process. If the two match, the process bypasses step 6080 without processing and ends the process once. finish.

In the motor drive interrupt (step 6080), the 17th
As shown in the figure, first, the exciting phase is
After updating according to the previous setting, in step 6082, the actual step number PO8 is incremented or decremented according to the update of the excitation phase. That is, the actual step number PO9 is increased or decreased by "1" so that the rotor position and the actual step number PO8 match. In step 6083, the target step number CMD and the actual step number PO
8, and if they match, perform the leaf processing of this motor drive interrupt at the step knob 6°84 and start the step motor 9.
stop rotating. If it doesn't match, Ste Tsubu 60B5,60
At E36, the next excitation phase and interrupt time are set so that the excitation phase is updated again, and this processing is temporarily terminated.

Since this embodiment is configured in this way, when the slip of the driving wheels 31, 33 is likely to be excessive due to engine braking, the throttle valve 7 is controlled in the opening direction, and the output torque of the engine 1 is increased. Since the negative torque is suitably reduced and the slip ratio is maintained at a suitable level, the stability of vehicle running is ensured. Dragging control can be achieved by simply using the conventional traction control device and simply changing the software program.

In the above embodiment, the drag control target slip rate S and the drag control start slip rate H are fixed inclinations, but may be changed according to the steering angle SA. For example, the settings may be made as shown in FIG. In other words, the settings are made so that during a turn, the slippage rate is suppressed and side force is obtained compared to when the vehicle is moving straight. Here, the steering angle SA is "0" in the straight-ahead state.
, a left turn is expressed as a negative value, and a right turn is expressed as a positive value. In this way, even more stable running is ensured even when turning.

In step 4395 of FIG. 6, the drive wheel acceleration GVR
Find L, GVRR, step 4500.45 in Figure 8.
20. Drive wheel deceleration GRL, GRR, GF at 4530
I is calculated using drive wheel acceleration GVRL, GVRR5 and drive wheel deceleration GRL for use in other processing not shown.

This is a process that requires C, RR, and GFI, and does not need to be executed as long as it is limited to drag control in this embodiment. In particular, when the slip state determination process in FIG. 8 is simplified, it becomes as shown in FIG. 21.

That is, if both rear wheel speeds VRL, F and VRRF are both greater than the drag control start speed vh (step 7010
．． 7030), nothing is done as no excessive slip has occurred due to engine braking, but if either the left rear wheel speed VRLF or the right rear wheel speed VRRF becomes equal to or lower than the drag control start speed vh (step 7010.7).
030), set the drag speed condition flag FTS (
Steps 7020 and 7040)b are then completed. The subsequent processing is as described above.

Furthermore, the driving wheel speeds VRLF, VRRF and slip state are predicted from the degree of decrease in the driving wheel accelerations GVRL, GVRR or the degree of increase in the driving wheel decelerations GRL, GRR, GF1, and early driving control is executed. You can do it like this.

In the above embodiment, the rear wheels 31, 33 correspond to the drive wheels M1, the engine 1 corresponds to the power generation means M2, the throttle valve 7 corresponds to the power adjustment means M3, and the ECL] 50 corresponds to the slip state detection means M4.゜Steps 4470, 4520, 7010.7 of the processes executed by the ECU 3O that correspond to the negative torque detection means M5 and the slip control means M6
The processing at step 030 corresponds to the processing as the slip state detection means M4, the processing at step 4620 corresponds to the processing as the negative torque detection means M5, and the throttle control base processing at step 6000 corresponds to the processing as the slip control means M6. do.

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

In addition to internal combustion engines, such as electric vehicles, drag control can be performed by controlling the amount of power supplied, and this is also an embodiment of the present invention.

In the above embodiment, the negative torque detecting means M5 determines that a negative torque is generated based on the degree of the accelerator operation amount (step 4B20). In addition, since the twist of the output shaft of engine 1 is reversed during engine braking compared to during normal driving,
The generation of negative torque may be detected from the reversal of the twist, and this may be used as a condition for determining whether to start drag control.

Effects of the Invention In the present invention, when negative torque is detected by the negative torque detection means M5, the slip control means M6 adjusts the power adjustment means M3 to control the power generated by the power generation means M2. The slip state of the driving wheel M1 is controlled to a predetermined state.

Therefore, excessive slip caused by engine braking is suppressed, and stable running of the vehicle is achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the basic configuration of the present invention, and FIG. 2 is a schematic configuration diagram showing an embodiment of the vehicle slip control device of the present invention.
Fig. 3 is a schematic flowchart of the entire drag control executed by the ECU, Fig. 4 is a detailed flowchart of the signal human power-based processing, Fig. 5 is a flowchart of vehicle speed interrupt processing, and Fig. 6 is a detailed flowchart of vehicle speed signal processing. , Fig. 7 shows the target driving wheel speed V for driving relative to the vehicle speed V.
FIG. 8 is a detailed flowchart of the slip state determination process, FIG. 9 is a detailed flowchart of the drag control start and end determination process, and FIG. FIG. 11 is a detailed flowchart of the fuel control U base process, FIG. 11 is a flowchart of the engine rotation interrupt process, FIG. 12 is a detailed flowchart of the throttle control base process, FIG. 13 is a detailed flowchart of the drive wheel torque TW calculation process, and FIG. 14 is a detailed flowchart of the drive wheel torque TW calculation process. A graph showing the relationship between the throttle opening degree and engine torque according to the engine rotational speed Ne, FIG. FIG. 17 is a detailed flowchart of motor drive interrupt processing, and FIG. 18 is a graph showing an example of setting the steering angle SA, target slip rate S, and drag control start slip rate H.
FIG. 19 is a graph showing the relationship between slip ratio, braking force, and side force, FIG. 20 is an explanatory diagram of steering angle SA, and FIG. 21 is a flowchart of another example of slip state determination processing. Ml... Drive wheel M2... Power generation means M3... Power adjustment means M4... Slip state detection means M5... Negative torque detection means M6... Slip control means 1... Engine 7. ...Throttle valve 31.33...Rear wheel (drive wheel) 50...ECU

Claims (1)

[Scope of Claims] 1. A power generating means mounted on a vehicle and generating power for driving the vehicle through drive wheels; a power adjusting means adjusting the amount of power generated by the power generating means; A slip state detection means for a drive wheel; a negative torque detection means for detecting that the power generation means is applying a negative torque to the drive wheel; and when negative torque is detected by the negative torque detection means. A slip control device for a vehicle, comprising: a slip control device that adjusts the power adjustment device to control a slip state of the driving wheels detected by the slip state detection device to a predetermined state.