JP2642104B2 - Vehicle propulsion control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion control device for a vehicle that prevents driving wheels from idling when the vehicle starts or accelerates.

2. Description of the Related Art Conventionally, as one type of such a control device, a slip amount of left and right drive wheels is measured based on a deviation between a rotation speed of left and right drive wheels and a rotation speed of a driven wheel, and the slip amount is set in advance. When the value exceeds the reference value, the brake devices provided for each drive wheel are individually driven, and the rotational speeds of the respective drive wheels are independently controlled so that the slip amount of each drive wheel becomes the reference value. What is known is.

In addition, when the slip control is independently performed for each drive wheel using the brake device in this way, when the vehicle starts, only one of the left and right drive wheels is located on a road surface where slippage is likely to occur. When the vehicle is running, it is possible to suppress the occurrence of slip and to secure the vehicle traveling performance.However, when only the rotation of one of the drive wheels is suppressed by the brake device during high-speed traveling or turning traveling of the vehicle, Under such driving conditions, for example, as described in Japanese Patent Application Laid-Open No. 58-16948, the propulsion control of the vehicle is performed when an acceleration slip occurs in any of the drive wheels as described in JP-A-58-16948. Some are configured to use drive torque control to reduce the drive torque transmitted to the drive wheels by suppressing the output torque of the engine.

[Problems to be Solved by the Invention] However, when only one of the left and right drive wheels slips as described above, the slip control is normally performed by brake control of the drive wheels, and the vehicle travels at high speed. In a vehicle propulsion control device configured to execute slip control in combination with drive torque control during driving and turning, not only does the switching of the control become complicated, but also the rotational speed of the drive wheels accompanying the switching of the control. However, there has been a problem that the vehicle suddenly changes, stable acceleration cannot be obtained, and riding comfort is deteriorated.

In addition, since the propulsion control is executed only by the brake control when the vehicle is traveling straight at a low speed such as when the vehicle starts, an excessive load is applied to the brake device at that time, and there is a problem that the life of the brake device is shortened.

Therefore, the present invention provides a propulsion control device for a vehicle that can reduce the load applied to the brake device when performing acceleration slip control that occurs when the vehicle is accelerated, and that enables the vehicle to always run stably without switching control. Made for purpose.

[Means for Solving the Problems] That is, the present invention made to achieve the above object has the following features.
As illustrated in FIG. 1, in order to prevent the drive wheels from slipping when the vehicle is accelerating, a brake device provided for each of the drive wheels is operated to suppress the rotational speed of the drive wheels and transmit the rotation to the drive wheels. A propulsion control device for a vehicle that suppresses a driving torque from a driving device for a vehicle, the driving wheel speed detecting means detecting respective rotational speeds of left and right drive wheels, and the rotational speeds of left and right driven wheels are respectively detected. Driven wheel speed detecting means, and among the rotational speeds of the left and right driven wheels and the left and right driven wheels detected by the respective detecting means, based on the rotational speed of the left driven wheel and the rotational speed of the left driven wheel, First slip amount calculating means for calculating a slip amount representing a slip state; and, among the rotational speeds of the left and right drive wheels and the left and right driven wheels detected by the respective detecting means, the rotational speed of the right drive wheel and the rotational speed of the right driven wheel. Based on the rotation speed, A second slip amount calculating means for calculating a slip amount representing a slip state of the drive wheels; and an average slip amount of the left and right drive wheels based on rotation speeds of the left and right drive wheels and the left and right driven wheels detected by the respective detection means. An average slip amount calculating means to be calculated, and a left or right driving wheel slip amount calculated by the first or second slip amount calculating means, respectively provided for the left and right drive wheels. When the reference value is equal to or greater than 1, the left and right drive wheel speed control means for driving the brake device provided on the drive wheel to control the rotational speed of the drive wheel, and the average slip amount calculation means Drive torque control means for controlling a drive torque from the drive device transmitted to each drive wheel when the average slip amount obtained is equal to or greater than a second reference value set in advance. And a vehicle propulsion control device comprising:

Here, as the driving wheel speed detecting means and the driven wheel speed detecting means, for example, a conventionally known electromagnetic or optical type rotating speed sensor which generates a pulse signal synchronized with the rotation of the driving wheel or the driven wheel is used. be able to.

Next, as the first slip amount calculating means, for example,
The deviation between the rotation speed of the left drive wheel and the rotation speed of the left driven wheel may be calculated as the slip amount of the left drive wheel. The second slip amount calculation means may be, for example, the rotation speed of the right drive wheel. And the rotational speed of the right driven wheel may be calculated as the slip amount of the right driven wheel. Examples of the average slip amount calculating means include an average rotational speed of the left and right driven wheels and an average rotational speed of the left and right driven wheel. The configuration may be such that the deviation from the speed is calculated as the average slip amount of the left and right driving wheels.

The slip state of the wheel can also be calculated as the slip ratio S by the following equation using the vehicle speed and the wheel speed as parameters: S = (wheel speed−vehicle speed) / wheel speed. You may comprise so that it may calculate as a slip ratio S by a formula. In this case,
The first slip amount calculating means may calculate the slip ratio of the left drive wheel using the wheel speed as the rotation speed of the left drive wheel and the vehicle speed as the rotation speed of the left driven wheel. The calculating means may calculate the slip ratio of the right driving wheel using the wheel speed as the rotation speed of the right driving wheel and the vehicle speed as the rotation speed of the right driven wheel. The average slip ratio of the left and right drive wheels may be calculated by setting the average rotational speed of the left and right drive wheels and the average vehicle speed of the left and right driven wheels as the average rotational speed of the left and right driven wheels.

Next, the left and right drive wheel speed control means, for example, if the brake device is a well-known hydraulic brake device that brakes wheels by hydraulic pressure, the brake is performed when the slip amount of the drive wheels becomes equal to or more than a first reference value. This can be realized by increasing the oil pressure and then decreasing the brake oil pressure when the slip amount falls below the first reference value.

Also, in this case, if the brake oil pressure is increased and decreased at a fixed rate, the rotation of the drive wheel may be excessively suppressed or the rotation of the drive wheel may not be quickly suppressed depending on the magnitude of the slip generated in the drive wheel. Therefore, it is desired to change the pressure increase and pressure reduction rate of the brake hydraulic pressure according to the magnitude of the slip generated on each drive wheel.

For example, the control amount is determined according to the deviation between the slip amount of the drive wheel calculated by the first or second slip amount calculating means and the first reference value, and the brake hydraulic pressure is accordingly adjusted. What is necessary is just to comprise so that a pressure increase or a pressure reduction rate may be controlled. More specifically, a high-pressure chamber in which the brake oil is controlled to a constant oil pressure and a reservoir tank for storing the brake oil are connected to the brake device via an electromagnetic valve, and the electromagnetic valve is connected to the slip amount of the drive wheels. And a first reference value, the motor may be driven at a duty ratio corresponding to a deviation between the pressure and the first reference value to control the pressure increase rate or the pressure decrease rate of the brake hydraulic pressure of the brake device.

In addition, as the brake device, in addition to the above-described hydraulic brake device, for example, an electromagnetic brake device or the like that brakes a magnetic body that rotates together with the wheels by an electromagnetic force may be used. in this case,
Since the braking force is obtained by an electric quantity such as a pulse or a voltage, the left and right driving wheel speed control means, when the slip amount of the left or right driving wheel becomes equal to or more than a first reference value set in advance, What is necessary is just to comprise so that the drive signal according to the deviation of the slip amount of a drive wheel and a 1st reference value may be generated.

Further, if the drive wheels slip during high-speed running or turning running of the vehicle, the running stability is greatly reduced. Therefore, under such operating conditions, it is desirable to prevent the occurrence of slip more quickly and more reliably. It is. Therefore, it is desired that the first reference value serving as the reference for the brake control be set according to the moving speed (vehicle speed) of the vehicle, the turning angle of the vehicle, and the like.

Next, when the driving device of the vehicle is an internal combustion engine, the driving torque control means can be realized by, for example, correcting the reduction of the amount of fuel supplied to the internal combustion engine, retarding the ignition timing, or reducing the amount of intake air. . Also in this drive torque control means, it is desirable to determine the control amount in accordance with the slip state of the drive wheels, as in the drive wheel speed control means, for example, the average slip amount of the left and right drive wheels and the second reference value. It is desired to determine the control amount in accordance with the deviation from. Also, it is desirable that the second reference value be set according to the vehicle speed, the turning angle of the vehicle, and the like, similarly to the first reference value.

[Operation and Effect of the Invention] In the vehicle propulsion control device of the present invention configured as described above, the slip amount of the left driving wheel is calculated by the first slip amount calculating means, and the second slip amount calculating means calculates the slip amount of the left driving wheel. Then, the slip amount of the right driving wheel is calculated, and the average slip amount of the left and right driving wheels is calculated by the average slip amount calculating means. When the slip amount of the left or right drive wheel calculated by the first or second slip amount calculation means becomes equal to or more than the first reference value, the slip is provided to the drive wheel by the operation of the drive wheel speed control means. The brake device is driven, and the rotation speed of the drive wheel is controlled. When the average slip amount of the left and right drive wheels calculated by the average slip amount calculation means is equal to or greater than the second reference value, the operation of the drive torque control means suppresses the drive torque from the drive device of the vehicle.

Therefore, irrespective of the running state of the vehicle, when the average slip amount of the left and right driving wheels becomes equal to or more than the second reference value, the driving torque from the driving device is suppressed, and the driving torque control method is different from the conventional method. Switching is not performed according to the running state of the vehicle. Therefore, according to the present invention, it is possible to prevent a sudden change in the rotation speed of the drive wheels when the drive torque control is switched, and to improve the running stability of the vehicle.
Further, when the average slip amount of the left and right drive wheels increases, the brake control and the drive torque control are performed simultaneously, so that the load applied to the brake device can be reduced and the life thereof can be extended.

Further, in the present invention, when the first slip amount calculating means calculates the slip amount of the left driving wheel, the rotation speed of the left driving wheel and the rotation speed of the left driven wheel are used to calculate the second slip amount. When the slip amount of the right driving wheel is calculated by the means, the rotation speed of the right driving wheel and the rotation speed of the right driven wheel are used. Therefore, according to the present invention,
The amount of slip of the left and right drive wheels can always be accurately calculated irrespective of the turning state of the vehicle, and the control accuracy of the slip control using the brake device by the left and right drive wheel speed control means can be improved. Become.

That is, in the present invention, the vehicle speed on the left side of the vehicle is represented by the rotation speed of the left driven wheel, the vehicle speed on the right side of the vehicle is represented by the rotation speed of the right driven wheel, and the slip amount of the left and right drive wheels is represented by the left and right. Since the calculation is performed based on the vehicle speed, the average speed of the left and right driven wheels is calculated as the vehicle speed, and the slip amount of the left and right drive wheels is calculated based on the average speed of the left and right driven wheels. It is possible to calculate more accurately, and as a result, the slip control for each driving wheel by the left and right driving wheel speed control means can be realized with high accuracy.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. The following examples show one embodiment of the present invention, and the present invention includes other embodiments without departing from the gist.

FIG. 2 shows the overall configuration of a propulsion control device for a rear wheel drive vehicle to which the present invention is applied.

As shown in the drawing, the propulsion control device according to the present embodiment includes a drive device M7 via a transmission 2 and a differential gear 4.
The rotation speed VRL of the left and right drive wheels 10RL, 10RR provided at the rear of the vehicle to which the drive torque from the internal combustion engine 6 is transmitted
Detecting VRR, the electromagnetic pickup type driving wheel speed sensors 12RL, 12RR as the driving wheel speed detecting means, and the rotational speed VFL of the left and right driven wheels 10FL, 10FR provided at the front of the vehicle.
An electromagnetic pickup type driven wheel speed sensor 12FL, 12FR as the reference speed detecting means for detecting VFR, a steering angle sensor 14 for detecting a steering angle of a steering wheel to detect a turning angle of the vehicle, An electronic control circuit 16 that calculates a control amount of the left and right drive wheels 10RL and 10RR and a control amount of the internal combustion engine 6 based on a detection signal from the sensor, and each drive wheel 10RL, 10RR
And a drive torque control device 20 that controls the drive torque from the internal combustion engine 6 according to the control amount calculated by the electronic control circuit 16. ing.

Here, the electronic control circuit 16 is configured as shown in FIG.

As shown in the figure, in the electronic control circuit 16, first, the left driven wheel speed calculating unit 22FL and the left driving wheel speed calculating unit 22RL perform the left driving based on the detection signals from the left driven wheel speed sensor 12FL and the left driving wheel speed sensor 12RL. The rotational speeds VFL and VRL of the driving wheel 10FL and the left driving wheel 10RL are calculated, respectively, and the left driving wheel slip amount calculation unit 24RL uses the calculation result as a parameter in the following equation (1).
Thus, the slip amount VL of the left drive wheel 10RL is calculated.

VL = VRL-VFL (1) Similarly, the right driven wheel speed calculation unit 22FR and the right drive wheel speed calculation unit 22RR calculate the detection signals from the right driven wheel speed sensor 12FR and the right drive wheel speed sensor 12RR. The rotational speeds VFR and VRR of the right driven wheel 10FR and the right driven wheel 10RR are calculated based on the right driven wheel 10RR and the right driven wheel 10RR is calculated by the right driven wheel slip amount calculation unit 24RR by the following equation (2) using the calculation result as a parameter.
Is calculated.

VR = VRR-VFR (2) Further, the rotational speeds VFL, VRL, VFR, VRR of the respective wheels calculated by the respective wheel speed calculating units are calculated by the average slip amount calculating unit 24.
Also output to RT. The average slip amount calculation unit 24RT is for calculating the average slip amount VT of the left and right drive wheels,
The average slip amount VT is calculated by the following equation (3) using the rotation speed of each wheel as a parameter.

VT = (VRL-VRR) / 2 (VFL + VFR / 2) (3) On the other hand, the steering angle calculation unit 26 calculates the steering angle θ of the steering wheel by the vehicle driver based on the detection signal from the steering angle sensor 14, and The steering angle θ calculated by the slip amount calculator 28 and the left and right driven wheel speed calculators 22FL, 2
Based on the left and right driven wheel speeds VFL and VFR calculated by 2FR,
First reference slip amount VSB and second reference slip amount V
ST is calculated.

The first reference slip amount VSB is determined by the left and right driving wheels 10RL and 10RR.
This corresponds to the above-mentioned first reference value for detecting the occurrence of slip and determining the control amount of the brake device. In the present embodiment, first, the left and right driven wheel speeds VFL, VFR
The average value of (VFL + VFR / 2 is calculated as the vehicle speed VC,
Based on the calculated body speed VC, as shown in FIG. 4 (A), the speed is constant when the body speed VC is equal to or lower than a predetermined value VCO, and changes at a predetermined slip rate (for example, 0.2) when the vehicle speed VC exceeds the predetermined value VCO. Calculate the slip amount f (VC),
Further, the value is corrected by a correction value KST corresponding to the steering angle θ as shown in FIG.
Is calculated.

The second reference slip amount VST is determined by the left and right driving wheels 10RL, 1
It is determined whether or not to control the driving torque from the internal combustion engine 6 by comparing with the average slip amount of 0RR, and corresponds to the above-described second reference value for determining the torque control amount.
The present embodiment is configured to use the same value as the first reference slip amount VSB. That is, the reference slip amount calculating section 28 obtains the first reference slip amount VSB as described above, and outputs the value as it is as the second reference slip amount VST.

Next, the first reference slip amount V calculated as described above
The SB, the left drive wheel slip amount VL, and the right drive wheel slip amount VR are input to the drive wheel control start determination unit 30. The drive wheel control start determination unit 30 determines whether one of the left and right drive wheel slip amounts VL and VR is equal to or larger than the first reference slip amount VSB and whether the condition for executing the brake control by the propulsion control device is satisfied. Left and right driving wheel slip amount VL,
When it is determined that any of the VRs is equal to or greater than the first reference slip amount VSB, the drive wheel control execution signal S1 is calculated until the drive wheel control end signal SE1 is input.

The drive wheel control execution signal S1 is output to the brake control device 18 and also to the left and right drive wheel control amount calculation units 32RL and 32RR in the electronic control circuit 16.

The left and right drive wheel control amount calculation units 32RL and 32RR are started by the drive wheel control execution signal S1 and calculate the control amounts BL and BR of the left and right drive wheels 10RL and 10RR while the drive wheel control execution signal S1 is input. In the left driving wheel control amount calculating unit 32RL, the first reference slip amount VSB calculated by the reference slip amount calculating unit 28 and the left driving wheel 10RL calculated by the left driving wheel slip amount calculating unit 24RL are calculated. The following equation (4) using the slip amount VL as a parameter: BL = K1 · (VL−VSB) (4) (where K1 is a constant) The control amount BL of the left drive wheel 10RL is calculated, and the right drive wheel control is performed. The amount calculating unit 32RR calculates the first reference slip amount VSB calculated by the reference slip amount calculating unit 28 and the slip amount V of the right driving wheel 10RR calculated by the right driving wheel slip amount calculating unit 24RR.
The control amount BR of the right drive wheel 10RR is calculated by the following equation (5) using R as a parameter and BR = K1 · (VR−VSB) (5).

Then, the calculated control amount B of each of the drive wheels 10RL and 10RR is calculated.
L and BR are output to the brake control device 18 as control signals for the drive wheels 10RL and 10RR.

The electronic control circuit 16 includes left and right drive wheels 10LR, 10RR.
Left and right drive wheel control end detection units 34 for detecting the end of the slip control of the left and right drive wheels 10RL and 10RR from the control amounts BL and BR of the left and right wheels, respectively.
RL and 34RR are provided.

Each drive wheel control end detection unit 34RL, 34RR is started by the drive wheel control execution signal S1 output from the drive wheel control start determination unit 30, and the control amount output from the left and right drive wheel control amount calculation units 32RL, 32RR. BL and BR are sequentially added, and when the result of the addition becomes 0 or a predetermined negative value, it is determined that the slip control of each drive wheel has been completed, and a control end signal for each drive wheel is output. And each drive wheel control end detecting section
The control end signal output from the 34RL, 34RR is input to the AND circuit 36, and when the control end signal is output from both drive wheel control end detection units 34RL, 34RR, the drive wheel control end signal is sent to the control start determination unit 30. SE1 is output. The output of the drive wheel control execution signal S1 from the drive wheel control start determination unit 30 is stopped by the drive wheel control end signal SE1, and the drive wheel control is performed until the next drive wheel control execution condition is satisfied. Stopped.

Next, the second reference slip amount VST calculated by the reference slip amount calculation unit 28 and the average slip amount VT of the left and right drive wheels 10RL and 10RR calculated by the average slip amount calculation unit 24RT are calculated by the torque control amount calculation unit 38 and This is input to the torque control start determination unit 40.

Similarly to the drive wheel control start determination unit 30, the torque control start determination unit 40 determines that the average slip amount VT is equal to or larger than the second reference slip amount VST, and controls the drive torque control of the internal combustion engine 6 by the propulsion control device. This is for determining whether or not the execution condition is satisfied. If it is determined that the average slip amount VT is equal to or larger than the second reference slip amount VST, the control unit determines whether the average slip amount VT is equal to or greater than the second reference slip amount VST. A torque control execution signal S2 is output to the driving torque control device 20 to execute the driving torque control.

Further, the torque control amount calculation unit 38 is activated by the torque control execution signal S2 output from the torque control start determination unit 40, and is controlled by the torque control start determination unit 49, similarly to the drive wheel control amount calculation units 32RL and 32RR. While the torque control execution signal S2 is being output, the internal combustion engine is given by the following equation (6) using the average slip amount VT and the second reference slip amount VST as parameters: VA = K2 · (VT−VST) (6) 6, and outputs the calculated torque control amount TA to the drive torque control device 20 as a torque control signal. As described later, in the present embodiment, the drive torque control device 20 is configured to control the throttle valve of the internal combustion engine 6 to suppress the drive torque. A valve opening / closing control amount is calculated.

Further, the drive torque control device 20 described later is provided with a torque control end detection unit 42 for detecting the end of the torque control from the number of torque control steps of the internal combustion engine 6 and the reference step number. The torque control end detection unit 42 is started by the torque control execution signal S2 output from the torque control start determination unit 40, and the control step number output from the control step number calculation unit 84 is output from the reference step number calculation unit 82. When the number of reference steps is smaller than the reference step number, it is determined that the torque control has been completed, and a torque control end signal SE2 is output. By this, the torque control start determining unit
The torque control is stopped until it is determined at 40 that the condition for executing the torque control is satisfied.

Next, a brake control device 18 that receives the drive wheel control execution signal S1 and the control signals BL and BR of the left and right drive wheels 10RL and 10RR output from the electronic control circuit 16 and drives and controls the brake devices of the left and right drive wheels 10RL and 10RR. Are configured as shown in FIG.

As shown, in the present embodiment, the left and right driving wheels 10RL, 10RR
Are provided with hydraulic brake devices 50RL and 50RR, and the brake control device 18 uses the brake oil pumped from the reverser 54 by the pump 52 and adjusted to a constant hydraulic pressure by the accumulator 56, and each hydraulic brake device 50RL. , 50RR, and the rotational speed of the left and right drive wheels 10RL, 10RR.

First, the brake control device 18 usually controls the vehicle by operating the brake pedal by the vehicle driver,
A brake master cylinder (not shown) and the left and right hydraulic brake devices 50RL and 50RR are connected to a hydraulic line switching valve 58 and a left hydraulic control valve 60RL, a hydraulic line switching valve 58 and a right hydraulic control valve 60, respectively.
Directly connected via RR.

The hydraulic pipeline switching valve 58 is a two-position valve for switching between the hydraulic pressure used for driving the hydraulic brake devices 50RL and 50RR between the hydraulic pressure from the brake master cylinder and the hydraulic pressure from the pump 52, as described above. Normally, each hydraulic brake device 80RL, 5
The drive control is switched from the electronic control circuit 16 to the brake master cylinder side so that the 0RR can be driven.
When S1 is input, the two-position valve drive circuit 62 is switched to the pump 52 side so that the slip control can be performed by the hydraulic pressure from the pump 52.

The left and right hydraulic control valves 60RL, 60RR use the high-pressure oil from the pump 52 transmitted through the hydraulic pipeline switching valve 58 when the slip control is executed, and each hydraulic brake device 50RL, 5RR.
A three-position valve for controlling the brake oil pressure of 0RR. Normally, the hydraulic line switching valve 58 is switched to the brake master cylinder side, so the hydraulic brake devices 50RL and 50RR are directly driven by the oil pressure from the brake master cylinder. The hydraulic pipeline switching valve 58 is connected to the hydraulic brake devices 50RL and 50RR so that the hydraulic pipeline switching valve 58
When it is switched to the side, the drive is controlled by the three-position valve drive circuits 64RL and 64RR in accordance with the control signals BL and BR from the electronic control circuit 16.

The three-position valve drive circuits 64RL and 64RR are activated by the drive wheel control execution signal S1 output from the electronic control circuit 16 and thereafter controlled by the electronic control circuit 16 until the drive wheel control execution signal S1 is stopped. Hydraulic control valve 60 according to signals BL and BR
RL, for controlling the drive of 60RR, in this embodiment,
The brake hydraulic pressure of the hydraulic brake devices 50RL and 50RR is controlled to increase or decrease according to the pressure increase or pressure reduction duty ratio D set as shown in FIG. 6 (A) according to the control signals BL and BR. That is, a time t (t = D · T) for increasing or decreasing the brake hydraulic pressure per a fixed time T in accordance with a control signal from the electronic control path 16 is obtained, and is shown in FIG. Hydraulic control valve
Drive control of 60RL and 60RR to make each hydraulic brake device 50RL and 50RR
It controls the RR brake oil pressure.

The hydraulic control valves 60RL and 60RR have a pressure increasing port a for communicating the hydraulic pipeline switching valve 58 and the hydraulic brake devices 50RL and 50RR, and a reverser via a two-position valve 66 when the brake control is executed.
Low pressure line 67 communicating with 54 and hydraulic brake device 50RL, 50R
The three-position valve drive circuits 64RL, 64RR are provided with a pressure reducing port b communicating with the R and a holding port c for shutting off these parts and holding the brake oil pressure. Duty control of 60RR between ports ac, hydraulic pressure control valves 60RL, 60R when brake hydraulic pressure is reduced
R is duty controlled between ports b and c.

The two-position valve 66 normally shuts off the reservoir 54 and the low-pressure line, and the two-position valve driving circuit 68 causes the reservoir 44 and the low-pressure line to be driven by the driving wheel control execution signal S1 from the electronic control circuit 16.
It is driven to communicate with 67.

Next, a drive torque control device 20 that receives the torque control execution signal S2 and the torque control signal TA output from the electronic control circuit 16 and controls the drive torque from the internal combustion engine 6 is configured as shown in FIG. .

As shown in the figure, in the present embodiment, the intake pipe 70 of the internal combustion engine 6 is
In addition to a throttle valve 74 that opens and closes the intake pipe 70 in conjunction with an accelerator pedal 72, a sub-throttle valve 76 for driving torque control is provided.
20 controls the amount of air taken into the internal combustion engine 6 by controlling the opening and closing of the sub throttle valve 76 by a step motor 78,
The driving torque from the internal combustion engine 6 is controlled.

The drive torque control device 20 includes a throttle valve 74
A throttle opening sensor 80 for detecting the opening of the
Based on the detection signal from the throttle opening sensor 80, the number of steps of the step motor 78 corresponding to the opening of the throttle valve 74 is calculated as the reference number of steps.

On the other hand, the torque control execution signal S2 and the torque control signal TA output from the electronic control circuit 16 are input to the control step calculator 84. Then, based on the input torque control signal TA, the control step number calculating section 84 sets a control amount for opening / closing the sub throttle valve 76 as a step value from the reference step number calculating section 82 with the reference step number as an initial value. It is calculated as the number of control steps of the motor 78.

Then, the control step number calculated by the control step number calculation section 84 is input to the motor drive circuit 86, and the step motor 78 is driven so that the step number of the step motor 78 becomes the control step number.

That is, in the torque control device 20, first, the step motor 78 is driven so that the number of steps of the step motor 78 becomes the reference step number calculated by the reference step number calculating section 82, and the sub throttle valve 76 is By closing the opening to the degree of opening, and then driving the step motor 78 in accordance with the control step number calculated by the control step number calculating section 84 based on the torque control signal TA to control the opening and closing of the sub-throttle valve 76, the internal combustion engine 6 The drive torque from the motor is suppressed.

In the vehicle propulsion control device of the present embodiment configured as described above, as shown in FIG. 8, when the vehicle starts or accelerates, for example, one of the drive wheels slips and the slip amount becomes the first. Is greater than or equal to the reference slip amount VSB, the drive wheel control execution signal S1 is output from the electronic control circuit 16 and the brake control is executed via the brake control device 18, and the rotational speed of the drive wheel in which the slip has occurred is directly suppressed. You. Further, at this time, when the average slip amount of the drive wheels becomes equal to or more than the second reference slip amount VST, drive torque control of the internal combustion engine 6 is also executed, thereby indirectly suppressing the rotational speed of the drive wheels.

For this reason, it is not necessary to switch the torque control method according to the running state of the vehicle as in the conventional device, and the running speed of the vehicle does not deteriorate due to a sudden change in the rotational speed of the drive wheel at the time of the control switching. Further, when the average slip amount generated in each drive wheel increases, the brake control and the drive torque control are performed at the same time. Therefore, when the slip control is performed at the time of starting the vehicle, the load applied to the brake device is reduced and its life is reduced. Can be extended. In other words, conventionally,
When starting a vehicle, in which a large drive torque is transmitted to the drive wheels,
When only one of the left and right driving wheels slips, the rotation of the driving wheels is suppressed only by the brake control, so the load applied to the braking device at that time is large, and the braking device is easily broken down. However, in the present embodiment, the driving torque control is executed simultaneously with the brake control under the driving condition in which the slip amount of the driving wheels becomes large, such as when the vehicle starts, so that the load applied to the brake device can be reduced, and the life of the brake device can be extended. Can be achieved.

In the present embodiment, the slip amount VL of the left drive wheel 10RL is
Is calculated as the difference between the rotation speed VRL of the left driving wheel 10RL and the rotation speed VFL of the left driven wheel 10FL, and the slip amount VR of the right driving wheel 10RR is calculated as the rotation speed VRR of the right driving wheel 10RR and the right driven wheel 1RL.
It is calculated as a deviation from the rotation speed VFR of 0FR. For this reason, the slip amount of the left and right drive wheels can always be accurately calculated regardless of the turning state of the vehicle, and the control accuracy of the slip control can be improved. That is, the vehicle speed on the left side of the vehicle is represented by the rotational speed of the left driven wheel 10FL, the vehicle speed on the right side of the vehicle is represented by the rotational speed of the right driven wheel 10FR, and the slip amount of the left and right drive wheels 10RL and 10RR is represented by the left and right. Since it is configured to calculate each based on the vehicle speed, the average speed of the left and right driven wheels is calculated as the vehicle speed, and the slip amount of the left and right driving wheels is calculated more as compared with a device that calculates the slip amount of the left and right drive wheels based on this. It can be calculated accurately.

Furthermore, in the present embodiment, the first reference slip amount VSB and the second reference slip amount VST are determined according to the running speed Vc of the vehicle obtained by averaging the rotational speeds of the left and right driven wheels, and the slip amount f (Vc ) Is corrected in accordance with the turning angle of the vehicle represented by the steering wheel operation angle θ, so that the steering angle θ, that is, the smaller the turning angle of the vehicle, is set to a smaller value. Under the driving condition in which the slip is likely to occur, the slip control is executed earlier, so that the running stability of the vehicle can be further improved.

In this embodiment, the turning angle of the vehicle is detected based on the steering angle θ of the steering wheel. However, the turning angle may be detected based on, for example, the rotational speed difference between the left and right driven wheels. In this embodiment, the first reference slip amount VSB
And the second reference slip amount VST, the same value is used. However, if these values are individually determined and the first reference slip amount VSB is set to a value smaller than the average slip amount VST, If the average slip amount VST is smaller than the first reference slip amount VSB, the propulsion control device can be configured as a propulsion control device that gives priority to drive torque control. Can be.

Further, in this embodiment, when executing the brake control,
Since the brake hydraulic pressure of each hydraulic brake device 40RL, 40RR is configured to be increased / decreased by a duty ratio set according to the control amounts BL, BR output from the electronic control circuit 16, the brake hydraulic pressure is increased. The pressure or pressure reduction rate can be optimally controlled in accordance with the slip state of each drive wheel, and the slip amount of each drive wheel is quickly converged to the first reference slip amount VSB to obtain good acceleration. You can do so.

Here, in the above embodiment, the electronic control circuit 16 is configured using various arithmetic circuits, but may be realized by a microcomputer configured using a CPU, a ROM, a RAM, and the like. In this case, by performing the slip control in accordance with the control program as shown in FIGS. 9 and 10, the operation can be performed in the same manner as in the above embodiment.

Hereinafter, slip control in the case where the electronic control circuit 16 is configured using a microcomputer will be briefly described with reference to the flowcharts of FIGS.

First, FIG. 9 shows a control amount calculation process repeatedly executed when the internal combustion engine 6 is operated.

As shown in FIG.
0, and the flags F1 and F2 used to execute the slip control and the various control amounts BL, BR, and TA, or the added values ΣBL and ΣBR of the control amounts BL and BR are initialized to 0. Is performed, and the process proceeds to step 110.

In step 110, the rotational speeds VFL, VFR, VRL, VRR of the respective wheels are calculated based on the detection signals from the respective wheel speed sensors, and then the process proceeds to step 120, where the calculated rotational speeds of the left and right driven wheels are calculated. Average value of speed VFL, VFR (VVFL + VFR)
/ 2 is calculated as the vehicle speed Vc. Next step 130
Then, based on the detection signal from the steering angle sensor 14, the steering angle θ
Then, the process proceeds to step 140 to calculate the first reference slip amount VSB and the second reference slip amount VST from the calculated vehicle body speed Vc and the steering angle θ as described above,
Move to step 150. In step 150, the slip amounts VL and VR of the left and right driving wheels 10RL and 10RR are calculated using the above equations (1) and (2) based on the rotational speeds of the respective wheels calculated in step 110. Transition.

In step 160, it is determined whether or not the flag F1 set when the brake control execution condition is satisfied in a process described later is in a reset state, that is, whether or not the brake control is currently being executed. If the brake control is not currently being executed, the process proceeds to step 170 to determine whether the calculated slip amount VL of the left driving wheel 10RL is equal to or larger than the first reference slip amount VSB calculated in step 140, It is determined whether the execution start condition of the brake control is satisfied. Where the left drive wheel
If the slip amount VL of 10RL is not equal to or greater than the first reference slip amount VSB and it is determined in step 170 that the condition for starting the execution of the brake control is not satisfied, the process proceeds to step 180, and this time the right drive wheel 10RR It is determined whether or not the execution start condition of the brake control is satisfied based on whether or not the slip amount VR is equal to or more than the first reference slip amount VSB. If it is determined that the slip amount VR of the right drive wheel 10RR is not equal to or greater than the first reference slip amount VSB and that the execution start condition of the brake control is not satisfied in step 180,
The process proceeds to step 230 described later.

On the other hand, if it is determined in step 170 or 180 that the step amount of any of the drive wheels has become equal to or greater than the first reference slip amount VSB and the execution condition of the brake control is satisfied, the flag F1 is set in step 190. Thereafter, the process proceeds to step 200, and outputs a drive wheel control execution signal S1 to the brake control device 18 to execute the brake control.

Next, when the processing of step 200 is executed, or when it is determined in step 160 that the flag F1 is in the set state, step 210 is executed, and the left The control amount BL of the drive wheel 10RL is calculated, and in step 220, the control amount BR of the right drive wheel 10RR is calculated by using the above equation (5).

In step 230, the average slip amount VT of the left and right driving wheels is calculated by the following equation (3) ′ VT = (VR + VL) / 2 (3) ′ obtained by modifying the equation (3).
In the subsequent step 240, it is determined whether or not the flag F2 set when the drive torque control execution condition is satisfied in a process described later is in a reset state, that is, whether or not the drive torque control is currently being executed. If not running,
The process proceeds to step 250 to determine whether or not the calculated average slip amount VT of the left and right driving wheels is equal to or greater than the second reference slip amount VST calculated in step 140, that is, the execution start condition of the drive torque control is It is determined whether or not it has been established.

When it is determined that the average slip amount VT of the left and right drive wheels is not equal to or greater than the second reference slip amount VST and that the execution start condition of the drive torque control is not satisfied in step 250,
The process proceeds to step 110, and the processes after step 110 are executed again. When it is determined in step 250 that the execution start condition of the drive torque control is satisfied, the process proceeds to step 260.
After setting the flag F2 and proceeding to step 270, the torque control execution signal is executed to execute the drive torque control.
S2 is output to the drive torque control device 20.

Next, when the process of step 270 is executed, or when it is determined in step 240 that the flag F2 is in the set state, step 280 is executed, and the internal combustion is performed using the above equation (6). The torque control amount TA of the engine 6 is calculated, and the process proceeds to step 110 again.

Next, FIG. 10 shows a control signal output process executed as an interrupt process every predetermined time.

As shown in the figure, when this process is executed,
Step 300 is executed to determine whether the flag F1 is set, that is, whether the brake control is currently being executed. If the flag F1 is in the reset state, the step
Shift to 310 and set the control amounts BL and BR of the left and right drive wheels 10RL and 10RR to 0
, And in subsequent step 320, the added values ΣBL, ΣBR of the control amounts BL, BR are set to 0. In the subsequent step 330, the output of the control execution signal S1 is stopped, and the process proceeds to the next step 340, in which the output of the drive wheel control signals BL and BR is stopped, and the process proceeds to step 400.

On the other hand, if it is determined in step 300 that the flag F1 is in the set state, that is, if the execution condition of the brake control is satisfied and the brake control is currently being executed, the process proceeds to step 350 to calculate the control amount. The control amounts BL and BR of the left and right drive wheels 10RL and 10RR calculated in the processing are output to the brake control device 18 as control signals. In the following step 360,
The output drive wheel control amounts BL and BR are added to the current drive wheel control amount addition values ΣBL and ΣBR to update the values. In the following step 370, it is determined whether or not the updated driving wheel control amount addition value ΣBL has become a negative value, and ΣBL <
If it is 0, the process proceeds to the next step 380; otherwise, the process proceeds to step 400. In step 380, it is determined whether or not the updated driving wheel control amount addition value ΣBR has become a negative value. If ＜ BR <0, the process proceeds to the next step 390, where the flag F1 is reset. Migrated to 400,
Otherwise, the process proceeds to step 400 as it is. Note that the processing in steps 370 and 380 is processing for determining the end of the brake control based on whether or not the added values ΣBL and ΣBR of the respective drive wheel control amounts BL and BR have become negative values. When the end of the process is determined, step 390 is executed to reset the flag F1, so that the brake control is stopped in the processes of steps 330 and 340 at the next execution of the process.

Next, in step 400, it is determined whether or not the flag F2 is set, that is, whether or not the drive torque control is currently being performed. If the flag F2 is in the reset state, the routine proceeds to step 410, where the drive torque control amount TA is set to 0.
Set to. In the following step 430, the output of the torque control execution signal S2 is stopped, and the process proceeds to the next step 440, where the output of the control signal TA is stopped, and the process is temporarily terminated.

On the other hand, if it is determined in step 400 that the flag F2 is in the set state, that is, if the drive torque control execution condition is satisfied and the drive torque control is currently being executed, the process proceeds to step 450, The drive amount control section 20 outputs the drive torque control amount TA calculated in the control amount calculation process to the drive torque control device 20 as a control signal. Then, in the subsequent step 470, it is determined whether or not the drive torque control end signal SE2 from the drive torque control device 20 is in the set state. If the drive torque control end signal SE2 is in the set state, the process proceeds to the next step 480. After resetting the flag F2, the process is temporarily terminated, otherwise, the process is terminated once. When the end of the torque control is determined in the process of step 470, step 480 is executed to reset the flag F2, so that step 430 and step 4 are executed at the next execution of the process.
The drive torque control is stopped in the process of 40.

Next, in the above embodiment, the control amounts BL and BR of the left and right drive wheels 10RL and 10RR are calculated according to the deviation between the slip amounts VL and VR of the respective drive wheels and the first reference slip amount VSB. Is calculated in accordance with the deviation between the average slip amount VT of each drive wheel and the second reference slip amount VST. However, the acceleration of each wheel is detected, and the acceleration of the left and right drive wheels is calculated. And the deviation between the average acceleration of the left and right driven wheels and the average acceleration of the left and right driven wheels, or the deviation between the average acceleration of the left and right driven wheels and the average of the left and right driven wheels. The responsiveness is improved, and the slip amount of the left and right drive wheels can be quickly controlled based on the control target (that is, the reference slip amount).

That is, as shown in FIG.
A wheel acceleration calculator 92F that differentiates the output signals from the wheel speed sensors 12FL, 12RL, 12FR, 12RR to calculate the rotational acceleration αFL, αRL, αFR, αRR of each wheel 10FL, 10RL, 10FR, 10RR.
L, 92RL, 92FR, 92RR, the deviation αL between the rotational acceleration αRL of the left driving wheel 10RL and the rotational acceleration αFL of the left driven wheel 10FL (= αRL−αF
L), and the rotational acceleration αRR of the right driving wheel 10RR and the right driven wheel 10F
Left and right wheel acceleration difference calculation units 94RL and 94RR for calculating the deviation αR (= αRR−αFR) of R from the rotational acceleration αFR, and the average rotational acceleration αD of the left and right drive wheels (= (αRL + αRR) / 2).
And the average rotational acceleration of the left and right driven wheels αF (= (αFL + αFR) /
An average acceleration difference calculation unit 94RT for calculating a deviation αT from 2) is provided. In each of the control amount calculation units 32RL ', 32RR', and 38 ', the following equations (7), (8), and (9) BL = K1 · (VL−VSB) + K3 · αL (7) BR = K1 · (VR−VSB) + K3 · αR (8) TA = K2 · (VT−VST) + K4 · αT (9) (However, K1 , K2, K3, and K4 are constants) by using an electronic control circuit 16 'configured to calculate the control amounts BL, BR, and TA of each drive wheel and the internal combustion engine 6 using
As the rotational accelerations αRL and αRR of the left and right driven wheels increase with respect to the rotational accelerations αFL and αFR of the left and right driven wheels, the control amounts BL and BR of the respective drive wheels are increased, and the average rotational acceleration αD of the left and right driven wheels is increased. As the average rotational acceleration .alpha.F becomes larger, the torque control amount of the internal combustion engine 6 is increased, the rotational speed of the drive wheels can be rapidly reduced, and the control responsiveness can be improved.

In this case, similarly to the above embodiment, the electronic control circuit 16 '
Can be constituted by a microcomputer.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, and FIGS.
FIG. 11 shows an embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing the configuration of the entire vehicle propulsion control device, FIG. 3 is a block diagram showing the configuration of an electronic control circuit, and FIG. FIG. 5 is a hydraulic system diagram showing a configuration of a brake control device, FIG. 6 is a diagram illustrating a brake hydraulic pressure control method by the brake control device, and FIG. 7 is an internal combustion engine and drive system. Schematic configuration diagram showing the configuration of the torque control device,
FIG. 8 is a diagram showing the operation of the embodiment, FIGS. 9 and 10 are flowcharts showing slip control executed when the electronic control circuit is constituted by a microcomputer,
FIG. 11 is a block diagram showing another configuration example of the electronic control circuit. 6 Internal combustion engine, 10RL, 10RR Drive wheel 10FL, 10RF Driven wheel, 14 Steering angle sensor 12FL, 12FR, 12RL, 12RR Wheel speed sensor 16 Electronic control circuit, 18 Brake Control device 20: Drive torque control device 40RL, 40RR: Hydraulic brake device 76: Secondary throttle valve

Continuation of the front page (72) Inventor Kiyotaka Ise 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-64-32955 (JP, A)

Claims (6)

(57) [Claims] In order to prevent the drive wheels from slipping when the vehicle is accelerating, a brake device provided for each of the drive wheels is operated to suppress the rotation speed of the drive wheels and to transmit the vehicle to the drive wheels. A propulsion control device for a vehicle, which suppresses a driving torque from a driving device, wherein a driving wheel speed detecting means for detecting rotation speeds of left and right driving wheels, respectively, and a sub-drive for detecting rotation speeds of left and right driven wheels, respectively. A wheel speed detecting means, a slip state of the left driving wheel based on the rotating speed of the left driving wheel and the rotating speed of the left driven wheel among the rotational speeds of the left and right driving wheels and the left and right driven wheels detected by the respective detecting means. First slip amount calculating means for calculating a slip amount representing the following: a rotational speed of the right drive wheel and a rotational speed of the right driven wheel among the rotational speeds of the left and right driving wheels and the left and right driven wheels detected by the respective detecting means. And based on the right drive wheel A second slip amount calculating means for calculating a slip amount representing a slip state; and an average for calculating an average slip amount of the left and right drive wheels based on rotational speeds of the left and right drive wheels and the left and right driven wheels detected by the respective detection means. A first reference which is provided for each of the left and right drive wheels, and wherein the slip amount of the left or right drive wheel calculated by the first or second slip amount calculation means is set in advance. When the value becomes equal to or more than the value, the left and right drive wheel speed control means for driving the brake device provided on the drive wheel to control the rotation speed of the drive wheel, and the average calculated by the average slip amount calculation means A drive torque control means for controlling a drive torque transmitted from the drive device to each drive wheel when the slip amount is equal to or greater than a second reference value set in advance. A propulsion control device for a vehicle. 2. The vehicle propulsion control device according to claim 1, wherein the first and second reference values are values set according to a moving speed of the vehicle and / or a turning angle of the vehicle. 3. The brake device is a hydraulic brake device, and the driving wheel speed control means increases or decreases or maintains the brake hydraulic pressure in accordance with a deviation between the slip amount of each driving wheel and a first reference value. The vehicle propulsion control device according to claim 1 or 2, wherein the duty control is performed. 4. The driving torque control means according to claim 1, wherein said driving torque control means controls the driving torque in accordance with a deviation between the average slip amount of the left and right driving wheels and a second reference value. A vehicle propulsion control device according to any one of the preceding claims. 5. The driving wheel speed control means on the left and right sides respectively determines the control amount of the brake device determined based on the slip amount of the driving wheel and the first reference value, based on the rotational acceleration of the driving wheel and the driving wheel. 5. The vehicle propulsion control device according to claim 1, wherein the vehicle propulsion control device is configured to correct based on a deviation from a rotational acceleration of a driven wheel on the same side to drive a brake device. 6. The drive torque control means determines the control amount of drive torque obtained based on the average slip amount of the left and right drive wheels and the second reference value by calculating the average rotational acceleration of the left and right drive wheels and the average rotation of the left and right driven wheels. 6. The vehicle propulsion control device according to claim 1, wherein the propulsion control device is configured to correct based on a deviation from acceleration and control a driving torque.