JPH0712802B2 - Car constant speed running control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a constant speed running control device for an automobile, which controls a vehicle to run while maintaining a preset target vehicle speed.

(Prior Art) A vehicle provided with a constant speed traveling device has been conventionally known, and in a vehicle provided with such a constant speed traveling device, in a predetermined driving state, a vehicle speed set by a driver, that is,
The vehicle is controlled to run at the target vehicle speed. JP 57-1914
No. 31, gazette discloses an example of such a constant speed traveling device, in the disclosed constant speed traveling device, means for setting a target vehicle speed, means for storing the set target vehicle speed, Means for performing constant speed traveling control based on the magnitude of the vehicle speed deviation between the stored target vehicle speed and the actual vehicle speed, that is, the actual vehicle speed, is provided. If the vehicle accelerates or decelerates before the target vehicle speed is reached after the travel setting operation is performed, set the target vehicle speed to that acceleration or the vehicle speed when the deceleration becomes zero. In this way, it is possible to prevent hunting when the actual vehicle speed converges to the target vehicle speed.

(Problems to be Solved) In the conventional constant speed traveling device as disclosed in Japanese Patent Laid-Open No. 191431/1982, the vehicle speed deviation is determined according to the magnitude of the vehicle speed deviation between the target vehicle speed and the actual vehicle speed. The throttle opening is controlled so as to become zero, whereby the actual vehicle speed converges to the target vehicle speed. However, even if the vehicle speed deviations are the same, if the target vehicle speed or the running condition of the vehicle such as the road slope or road surface resistance is different, the running resistance will be different, so that the target vehicle speed is reached. The required output, that is, the driving force, is different. Therefore, the required control amount of the throttle opening also changes depending on the target vehicle speed or the running state.
The conventional method of simply controlling the throttle opening according to the magnitude of the vehicle speed deviation from the target vehicle speed has a problem that good convergence to the target vehicle speed cannot be obtained.

(Means for Solving the Problem) The present invention provides a constant-speed traveling device for an automobile, which is configured in view of the above circumstances and which can stably and quickly converge to a target vehicle speed set. It is intended to be provided.

The constant speed traveling control device of the present invention includes a throttle valve provided in the intake passage, an actuator for adjusting the opening of the throttle valve, a vehicle speed detecting means for detecting the actual vehicle speed of the vehicle, and a target for setting the target vehicle speed of the vehicle. Vehicle speed setting means, deviation detecting means for detecting a vehicle speed deviation between the actual vehicle speed and the target vehicle speed,
A basic throttle opening degree setting means for setting a basic throttle opening degree for controlling the throttle valve based on the vehicle speed deviation from the deviation detecting means; a running state detecting means for detecting a running state of the vehicle; and the deviation detecting means. Target driving force calculating means for calculating a target driving force according to an output signal from the traveling state detecting means, and a target throttle opening degree for calculating a throttle opening control amount from the basic throttle opening degree according to the target driving force. And a feedback control means for controlling the throttle opening by operating the actuator so that the actual vehicle speed converges to the target vehicle speed based on the output signal from the target throttle opening control amount calculating means. It is characterized by that.

According to the present invention, first, the vehicle speed deviation between the actual vehicle speed and the target vehicle speed is obtained, and then the approximate value of the throttle opening control, that is, the basic throttle opening is calculated based on the magnitude of the vehicle speed deviation. . Further, the driving force necessary for the vehicle to reach the target vehicle speed is required in consideration of the traveling state of the vehicle, that is, the road gradient, road surface resistance, and the like. Then, the opening of the throttle valve that should be finally controlled according to the magnitude of this driving force, that is, the target throttle opening is determined, and the opening of the throttle valve is controlled to the above-mentioned target throttle opening via an actuator. It is supposed to be done.

In this case, in a preferred mode, the constant speed traveling device of the present invention is provided with a map of the driving force required to converge to the target vehicle speed according to the target vehicle speed and the magnitude of the vehicle speed deviation, and based on this map The required driving force value can be obtained. Then, the target throttle opening control amount is determined based on the final target driving force obtained by correcting the value of the driving force obtained from the map in consideration of the traveling state.

(Advantages of the Invention) In the conventional constant speed traveling device, the throttle opening is simply controlled according to the magnitude of the vehicle speed deviation, so that the target vehicle speed or the vehicle speed deviation and the throttle opening control amount are changed when the traveling state changes. The relationship is changed, and as a result, the constant speed traveling control becomes unstable and the convergence is deteriorated. However, in the constant speed traveling device of the present invention, in determining the control amount of the throttle opening, first, the desired value of the throttle opening control amount based on the vehicle speed deviation, that is,
The basic throttle opening is obtained to give a basic throttle control amount. Next, the target driving force in consideration of the target vehicle speed and the traveling condition is calculated, and by the target throttle opening control amount obtained based on this target driving force,
The basic throttle opening is corrected precisely according to the driving conditions.

Therefore, the constant speed traveling control according to the present invention can quickly converge to the target vehicle speed, as compared with the conventional constant speed traveling control that simply determines the throttle opening control amount according to the magnitude of the vehicle speed deviation. It is possible to perform highly accurate constant speed traveling control. Further, even if the target vehicle speed, the traveling state, etc. change, the problem that the control becomes unstable does not occur.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows a control system of a constant speed traveling device according to one embodiment of the present invention. The vehicle 1 of this example includes an engine 2 and an automatic transmission 3 connected to the engine 2, and a drive shaft 5 for driving wheels 4 is connected to the automatic transmission 3. The engine 2 is provided with an ordinary type intake system, and a throttle valve for controlling the amount of intake air into the combustion chamber is installed in the intake passage of this intake system. A throttle actuator 6 is provided to adjust the opening of the throttle valve. The vehicle 1 of this example is provided with a controller 7 preferably including a microcomputer, and the actuator 6 is operated by a command signal from the controller 7. Further, the automatic transmission 3 is equipped with a gear position sensor 8 for detecting the gear stage in operation, and a signal indicating the detected gear stage is input to the controller 7.

Further, the transmission 3 is equipped with a gear shift actuator 9 for selectively actuating a predetermined gear stage, and the actuator 9 is actuated by a signal from the controller 7. Also, the drive shaft 5
A vehicle speed sensor 10 for generating a pulse signal is attached to the vehicle, and a signal representing the vehicle speed from the vehicle speed sensor 10 is also input to the controller 7. Further, the controller 7 is provided with signals from various switches provided by the driver's operation, that is, an acceleration switch for increasing the target vehicle speed.
11, a deceleration switch 12 for reducing the target vehicle speed, a return switch 13 for restarting constant speed traveling control, a main switch 14 that is turned on when performing constant speed traveling control, a constant speed when control operation is performed Signals are input from the brake switch 15 for canceling the traveling control and the transmission switch 16 for canceling the constant speed traveling control when the automatic transmission 3 is in neutral.

The controller 7 operates when a switch input circuit 17 that receives signals from the various switches described above, vehicle speed detection means 18 that calculates the actual vehicle speed of the vehicle, and accelerator pedal 19 are operated.
The operation amount, that is, an accelerator position detecting means 20 for detecting an accelerator opening position, a basic throttle opening calculating means 21 for calculating a basic throttle opening on the basis of a signal from the accelerator position detecting means or a signal representing a vehicle speed deviation. A target vehicle speed setting circuit 23 for setting a target vehicle speed on the basis of signals from the slope detecting means 22 for detecting the slope of the road surface, the switch input circuit 17 and the vehicle speed detecting means 18, the target vehicle speed setting circuit
23, a target driving force of the vehicle is calculated based on signals from the traveling resistance predicting means 24 for predicting the traveling resistance of the vehicle based on the signals from the gradient detecting means 22, the target vehicle speed setting circuit 23 and the vehicle speed detecting means 18. Target driving force calculating means 25, further vehicle speed detecting means 18, running resistance predicting means 24, and shift determining means 26 for determining an appropriate shift stage of the automatic transmission based on signals from the target vehicle driving force calculating means 25. Each has.

Further, the controller 7 includes a vehicle speed detecting means 18, a running resistance predicting means 24, a target driving force calculating means 25, and the shift determining means.
Based on the signal from 26, a final throttle opening calculation means 27 for calculating the final throttle opening control amount required for constant speed traveling control is provided, and the signal from this final throttle opening calculation means 27 is Output to the throttle actuator 6 via the throttle opening control means 28.

Further, the controller 7 is provided with shift control means 29 for controlling the shift stage of the automatic transmission based on the signal from the shift determination means, and the signal from this shift control means 29 is inputted to the shift actuator 6. ing.

Further, the controller 7 includes a target air-fuel ratio calculation means 30 for calculating a target air-fuel ratio based on signals from the traveling resistance prediction means 24 and the target driving force calculation means 25, and the signal from the target air-fuel ratio calculation means 30 is a fuel. The fuel injection correction means 31 is input to the injection correction means 31 and outputs a command signal to the fuel injection means 32 so as to prohibit the power enrichment. The signal from the throttle opening control means 28 is also input to the slope detection means 22 and the shift determination means 26.

The control of this example will be described below.

FIG. 2 shows a main flowchart of the control of this example.

First, the controller 7 initializes the system and at the same time, the vehicle speed sensor 10, the gear position sensor 8, the accelerator pedal 19, the acceleration switch 11, the deceleration switch 12, and the return switch.
The signals from 13, the main switch 14, the brake switch 15, the transmission switch 16, etc. are read and these signals are A / D converted. Next, the controller 7 causes the basic throttle opening calculation means 21 to calculate the basic throttle opening (THOBJB) from the accelerator position signal A / D converted by the accelerator position detection means 20.

Next, the controller 7 executes the constant speed traveling control subroutine shown in FIG. 3 and FIG. 4 to calculate the throttle opening amount (THASC) required for constant speed traveling control.

Then, the basic throttle opening (THOBJB) and the throttle opening amount for constant speed running control (THASC) are compared, and when the throttle opening amount (THASC) is large, the throttle opening amount (THASC) is set to the target throttle opening amount. Set to (THOBJ) to perform throttle control, basic throttle opening (THOBJB)
If is large, the basic throttle opening (THOBJB) is set to the target throttle opening (THOBJ) and throttle control is performed.

Next, the constant-speed traveling control will be described. In FIG. 3, the controller 7 includes a main switch 14, a brake switch 15 (ON when the brake is not operated), and a transmission switch 16 (not neutral, but any shift stage). ON) is ON and the deceleration switch 12 or the acceleration switch 11 is not being operated, the constant speed traveling control is performed.

When the vehicle satisfies the constant speed running control start condition, the controller 7 executes the subroutine shown in FIG. 7, sets the target vehicle speed (VSOBJ), and performs the constant speed running control.

Further, when the acceleration switch 11 is operated, the controller 7 increases the target vehicle speed (VSOBJ) by a constant value for each operation, and when the deceleration switch 12 is operated, it is a constant value for each operation. Only reduce. Further, when the return switch 13 is operated, the storage vehicle speed (MRVS) stored in the predetermined memory is set to the target vehicle speed (VSOBJ) and the constant speed traveling control is started.

Next, the controller 7 executes the subroutine shown in FIG. 6 at every timer setting time to calculate the road surface gradient.

Next, the constant speed traveling control routine described below is executed every time a predetermined time elapses. That is, when a predetermined time has elapsed, the controller 7 compares the actual vehicle speed (VSR) calculated by the interrupt execution subroutine shown in FIG. 5 with the target vehicle speed (VSOBJ), and then compares the actual vehicle speed (VSR) with the actual vehicle speed (VSR). Calculate the deviation (DEFVS) from the target vehicle speed (VSOBJ).

Then, the vehicle speed deviation (DEFVS) is a predetermined value, 15K in this example.
When it exceeds m / h, the constant speed running control is stopped and the throttle opening amount for constant speed running control (THASC), the target vehicle speed (VSOBJ) and the integral element parameter (WKINT) are initialized.

When the vehicle speed deviation (DEFVS) is within 15 km / h, the proportional element (P) for calculating the final target driving force (TROBJ)
To calculate. In this case, the proportional element (P) is the vehicle speed deviation (DEFV
It is obtained by multiplying S) by a predetermined proportional data (DP). Next, the target vehicle speed (VSOBJ) is the actual vehicle speed (VSR)
If it is larger, the proportional element (P) is added to the target driving force (TROBJ). If the actual vehicle speed (VSR) is larger than the target vehicle speed (VSOBJ), the proportional element (P is calculated from the target driving force (TROBJ). P) to reduce the current target driving force (TROB
Correct J).

Next, the controller 7 calculates the integral element (I) from the integral data (DI) in order to calculate the final target driving force (TROBJ). Then, the target vehicle speed (VS
If OBJ) is greater than the actual vehicle speed (VSR), the integral element (I) is added to the integral element parameter (WKINT) to obtain the actual vehicle speed (V
When SR) is larger than the target vehicle speed (VSOBJ), the current target driving force (TROBJ) is corrected by subtracting the integral element (I) from the integral element parameter (WKINT).

Next, since the power transmission efficiency changes depending on the oil temperature for the automatic transmission, the controller 7 calculates a correction coefficient Ko that increases the target driving force (TROBJ) as the oil temperature is lower, and calculates this correction coefficient Ko. This is corrected by multiplying the target driving force (TROBJ).

Next, the controller 7 uses the road surface slope obtained from the subroutine shown in FIG. 6 and the actual vehicle speed (VSR) obtained from the subroutine shown in FIG. 5 to obtain the predicted vehicle resistance obtained from the interruption subroutine shown in FIG. The target driving force (TROBJ) is further corrected by (RLOAD) to calculate the final target driving force (TROBJ).

Next, the controller 7 executes the shift control subroutine shown in FIG. 8 to determine the optimum shift speed (GPR) of the automatic transmission according to the current traveling state of the vehicle.

Next, the controller 7 determines the throttle opening amount (T) for constant speed travel control based on the final target driving force (TROBJ), the actual vehicle speed (VSR), and the optimum shift speed (GPR) obtained by the above procedure.
HASC) is calculated. In this case, the controller 7 has a map showing the relationship between the final target driving force (TROBJ), the actual vehicle speed (VSR), and the throttle opening amount for constant speed traveling control (THASC) for each shift speed. Using the map, the throttle opening amount for constant speed running control (THAS
Determine C).

The throttle opening amount for constant speed traveling control (THASC) calculated by the constant speed traveling control subroutine of FIGS. 3 and 4 is the target throttle opening degree when the predetermined condition is satisfied in the main routine of FIG. (THOBJ), and the throttle opening is controlled by the execution of the interrupt routine shown in Fig. 10 (THASC)
Throttle control is performed via the throttle opening control means, that is, the throttle actuator 6 so as to converge to.

Next, a procedure for obtaining variables used in the constant speed traveling control subroutine of FIGS. 3 and 4 will be described.

FIG. 5 shows a flowchart of an interrupt routine for obtaining the actual vehicle speed (VSR) of the vehicle. In calculating the actual vehicle speed (VSR), the controller 7 reads the pulse signal from the vehicle speed sensor 10 and measures the vehicle speed pulse period (VST). Next, this vehicle speed pulse period (VS
T) is averaged to calculate the actual vehicle speed (VSR).

FIG. 6 shows a flowchart of the road surface gradient detection subroutine.

In FIG. 6, the controller 7 indicates that the average vehicle speed (VSE) for the past T seconds and the average throttle opening (T
HE) is calculated. Next, based on the above-mentioned average vehicle speed (VSE) and average throttle opening (THE), the average driving force (TRACE) and running resistance without a gradient (RROAD)
Ask for.

Next, the controller 7 obtains the difference between the average driving force (TRACE) and the running resistance (RROAD), and sets this value as the acceleration expected to occur per unit vehicle weight, that is, the virtual acceleration (ACCV). .

Further, the controller 7 changes the vehicle speed in the past T seconds (VS
D) is calculated, and the speed change per unit time, that is, the average acceleration (ACCE) is calculated.

Then, the difference between the virtual acceleration (ACCV) and the average acceleration (ACCE) is divided by the gravitational acceleration to obtain the road surface gradient (RAMP).

Figure 7 shows the predicted resistance of the vehicle (RLOAD), the target vehicle speed (VSO
BJ), and a subroutine for obtaining the memory vehicle speed (MRVS) are shown.

In FIG. 7, the controller 7 obtains a predicted running resistance (RLOAD) using a map based on the actual vehicle speed (VSR) obtained in FIG. 5 and the road surface gradient (RAMP) obtained in FIG. Next, set the desired value of the integral element parameter (WKINT), and set the actual vehicle speed (VSR) to the memory vehicle speed (MRVS).
Is stored in a predetermined storage location. Further, the vehicle speed value set by the driver is stored as the target vehicle speed (VSOBJ).

Referring to FIG. 8, there is shown a flowchart of a shift control subroutine for setting a shift speed (GPR) of the automatic transmission 3.

In this routine, the controller 7 first detects the current gear stage (GPR) from the signal from the gear position sensor 8. Next, the controller 7 obtains the maximum driving force (TRMAX) at the gear position from the map showing the relationship between the actual vehicle speed (VSR) and the maximum driving force (TRMAX) that can be exhibited at each gear position (GPR). If the maximum driving force (TRMAX) of the gear is smaller than the target driving force (TROBJ), it is impossible to maintain the gear and maintain the required driving force. A command signal is sent to the shift control means, that is, the shift actuator 9 so as to shift down.

When the maximum driving force (TRMAX) of the gear is greater than the target driving force (TROBJ), the controller 7 causes the margin driving force (STR) in the gear, that is, the maximum driving force (TRMAX) and the target driving force. The difference with the force (TROBJ) is calculated, and if the margin driving force exceeds a certain value, it is determined that the margin driving force is sufficient, and a shift-up signal is output to the shift actuator 9. If the surplus driving force is not sufficient, the gear position is not changed.

FIG. 9 shows a flow chart of the air-fuel ratio control subroutine. In this routine, the controller 7
Calculates the target air-fuel ratio (AFOBJ) using a map based on the target driving force (TROBJ) and actual vehicle speed (VSR) values.

Then, based on the value of the target air-fuel ratio (AFOBJ), it is determined whether or not the current operating condition satisfies the power enrichment condition. In this case, the controller 7 determines that the target air-fuel ratio (AFOBJ) is in the power enrichment range when the target air-fuel ratio (AFOBJ) is equal to or greater than a predetermined value. However, in the control of this example, when the constant speed traveling control is performed, the power enrichment is not performed. Therefore, the power enrichment prohibition signal is sent to the fuel injection means.

As described above, in the constant speed traveling control of this example, the throttle opening is not controlled simply according to the vehicle speed deviation as in the conventional case, but first, the throttle opening control is performed according to the magnitude of the vehicle speed deviation. The desired value of the amount, that is, the basic throttle opening degree is given, then the target driving force according to the running state is obtained, and finally the throttle opening degree is controlled according to the magnitude of the target driving force. Therefore, the actual vehicle speed can be quickly converged to the target vehicle speed, and highly accurate constant speed traveling control can be performed.

In the above-described embodiment, when the shift control is performed, the maximum driving force and the target driving force of the shift stage are compared with each other, but the shift control can be performed by using other means. .

For example, in FIG. 11, focusing on the throttle opening,
The flowchart of the shift control subroutine when performing shift control between the fourth speed and the fourth speed is shown. In FIG. 11, the controller 7 performs the shift control in
The gear position is determined, and if the current gear is the third speed, it is determined whether the throttle opening is smaller than a predetermined value Θ ₂ , and if it is smaller than the predetermined value Θ ₂ , the shift control means shifts up. Send a signal. On the other hand, when the value is not smaller than the predetermined value Θ ₂ , it is determined that the traveling margin at the third speed is insufficient, and the vehicle travels while maintaining the third speed. If the current gear position is the fourth speed, the throttle opening is determined whether larger than the predetermined value theta ₁ when a predetermined value theta greater than _1,
When it is determined that the driving force is not measured, a downshift signal is output to the shift control means.

[Brief description of drawings]

FIG. 1 is a control system diagram of a constant speed traveling device according to one embodiment of the present invention, FIG. 2 is a flow chart of a main routine of control using the device of FIG. 1, and FIGS. FIG. 5 is a flowchart of a subroutine for performing constant speed traveling control according to the embodiment of the present invention, FIG. 5 is a flowchart of an interrupt routine for calculating an actual vehicle speed, and FIG. 6 is a subroutine for calculating a road gradient. Flow chart of the
FIG. 7 is a flowchart of a subroutine for calculating a predicted running resistance of the vehicle, a target vehicle speed, and a stored vehicle speed, and FIG. 8 is a flowchart of a shift control subroutine for calculating an optimum shift speed according to a running state. FIG. 10 is a flow chart of an air-fuel ratio control subroutine for prohibiting power enrichment, FIG. 10 is a flow chart of a throttle opening control execution routine, and FIG. 11 is a case where shift control is performed by a method different from that of FIG. 5 is a flowchart of a shift control subroutine of FIG. 1 ... Vehicle, 2 ... Engine, 3 ... Automatic transmission, 5 ...
… Drive axis, 6 …… Throttle actuator, 7 …… Controller, 8 …… Gear position sensor, 9 …… Shift actuator, 10 …… Vehicle speed sensor, 11 …… Acceleration switch, 12 …… Deceleration switch, 13 …… Return Switch, 14 ……
Main switch, 15 ... Brake switch, 16 ... Transmission switch, 19 ... Accelerator pedal, 32 ...
... Fuel injection means.

Claims (1)

[Claims] 1. A throttle valve provided in an intake passage, an actuator for adjusting an opening of the throttle valve, a vehicle speed detecting means for detecting an actual vehicle speed of the vehicle, and a target vehicle speed setting means for setting a target vehicle speed of the vehicle. Deviation detecting means for detecting a vehicle speed deviation between the actual vehicle speed and the target vehicle speed, and basic throttle opening degree setting means for setting a basic throttle opening degree for controlling the throttle valve based on the vehicle speed deviation from the deviation detecting means. A driving state detecting means for detecting a traveling state of the vehicle; a target driving force calculating means for calculating a target driving force according to output signals from the deviation detecting means and the traveling state detecting means; Target throttle opening control amount calculation means for calculating the throttle opening control amount from the basic throttle opening, and based on an output signal from the target throttle opening control amount calculation means Cruise control of a motor vehicle, characterized in that the actual vehicle speed is a feedback control means for controlling the throttle opening by operating the actuator such that it converges to the target vehicle speed are.