JPS62231831A - Constant speed travel control device for automobile - Google Patents

Abstract

PURPOSE:To make a convergence into a target vehicle speed favorable by providing a means of calculating the controlled variable of a throttle opening from a basic throttle opening and operating an actuator based on the output signal of said means and converging to a target vehicle speed. CONSTITUTION:A controller 7 has a target driving force operating means 25 for operating a target driving force, and a throttle opening operating means 27 for operating a throttle opening controlled variable which is necessary for constant speed travel control. When determining a controlled variable, first, a basic throttle opening is obtained based on a vehicle speed deviation and, then, a target driving force is calculated with a target vehicle speed and a traveling condition, etc. taken into consideration, and the basic throttle opening is corrected in accordance with the traveling condition. Thereby, the vehicle speed can be rapidly converged into the target vehicle speed, without causing an unstable control even if the target vehicle speed and the traveling condition, etc. are changed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a constant speed cruise control device for an automobile that controls the vehicle to travel while maintaining a preset target vehicle speed.

(Prior Art) Vehicles equipped with a constant speed traveling device have been known for a long time. In a vehicle equipped with such a constant speed traveling device, in a predetermined driving state, the vehicle speed set by the driver, that is,
The vehicle is controlled to run at the target vehicle speed. JP-A-57-1
An example of such a constant speed traveling device is disclosed in Japanese Patent No. 91431, and the disclosed constant speed traveling device includes means for setting a target vehicle speed, means for storing the set target vehicle speed, Means for performing constant speed driving 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 reaching the target vehicle speed after the travel setting operation is performed, the target vehicle speed is set to the vehicle speed at which the acceleration or deceleration reaches zero. In this way, hunting when the actual vehicle speed converges to the target vehicle speed can be prevented.

(Problem to be Solved) In the conventional constant speed traveling device as disclosed in the above-mentioned Japanese Patent Laid-Open No. 57-191431, the vehicle speed deviation is determined according to the size of the vehicle speed deviation between the target vehicle speed and the actual vehicle speed. The throttle opening degree is controlled so that the actual vehicle speed becomes zero, and the actual vehicle speed converges to the target vehicle speed. However, even if the size of the vehicle speed deviation is the same, if the target vehicle speed or the vehicle running conditions such as the road surface gradient or road resistance are different, the amount of running resistance will be different, so it is difficult to reach the target vehicle speed. The required output, that is, the driving force, differs. For this reason, the necessary control amount of the throttle opening also changes depending on the target vehicle speed or the driving condition.As a result, the conventional method of simply controlling the throttle opening according to the size of the vehicle speed deviation from the target vehicle speed There is a problem that good convergence to the target vehicle speed cannot be obtained.

(Means for Solving the Problems) The present invention provides a constant speed traveling device for an automobile that is constructed in view of the above circumstances and is capable of stably and quickly converging a set target vehicle speed. is intended to provide.

The constant speed cruise control device of the present invention includes a throttle valve provided in an intake passage, an actuator that adjusts the opening degree of the throttle valve, a vehicle speed detecting means that detects the actual vehicle speed of the vehicle, and a target vehicle speed that sets the target vehicle speed of the vehicle. a vehicle speed setting means; a deviation detection means for detecting a vehicle speed deviation between the actual vehicle speed and the target vehicle speed;
basic throttle opening setting means for setting a basic throttle opening for controlling the throttle valve based on the vehicle speed deviation from the deviation detecting means; driving state detecting means for detecting the driving state of the vehicle; and the deviation detecting means. a target driving force calculating means for calculating a target driving force according to an output signal from the driving state detecting means; and a target throttle opening for calculating a throttle opening control amount from the basic throttle opening according to the target driving force. A control amount calculation means, 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 calculation means. It is characterized by:

According to the present invention, first, the vehicle speed deviation between the actual vehicle speed and the target vehicle speed is determined, and then, based on the magnitude of this vehicle speed deviation, the approximate value for throttle opening control, that is, the basic throttle opening is calculated. . Furthermore, the driving force required to make the vehicle reach the target vehicle speed is determined by taking into consideration the running state of the vehicle, that is, the gradient of the road surface, road surface resistance, and the like. Then, the opening degree of the throttle valve to be finally controlled, that is, the target throttle opening degree, is determined according to the magnitude of this driving force, and the opening degree of the throttle valve is controlled to the target throttle opening degree via the actuator. It is now possible to do so.

In this case, in a preferred embodiment, 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 size of the vehicle speed deviation, and based on this map, the The required driving force value can be obtained. Then, the target throttle opening control amount is
It is determined based on the final target driving force obtained by correcting the driving force value obtained from the map in consideration of the driving condition.

(Effects of the Invention) In conventional constant speed driving systems, the throttle opening was simply controlled according to the size of the vehicle speed deviation, so when the target vehicle speed or the driving condition changes, the difference between the vehicle speed deviation and the throttle opening control amount is changed. The problem is that the relationship changes, and as a result, the constant speed driving control becomes unstable and convergence deteriorates.

However, in the constant speed traveling system of the present invention, in determining the throttle opening control amount, first, the initial value of the throttle opening control amount, that is, the basic throttle opening is determined based on the vehicle speed deviation, and the basic throttle opening is determined based on the vehicle speed deviation. It is designed to give a controlled amount. Next, a target driving force is calculated taking into account the target vehicle speed, driving conditions, etc., and the basic throttle opening is precisely corrected according to the driving conditions using the target throttle opening control amount obtained based on this target driving force. That's what I do.

Therefore, the constant speed cruise control according to the present invention can converge to the target vehicle speed more quickly than the conventional constant speed cruise control that simply determines the throttle opening control amount according to the magnitude of the vehicle speed deviation. Highly accurate constant speed driving control can be performed. Furthermore, even if the target vehicle speed, driving condition, etc. change, the problem that control becomes unstable due to this does not occur.

(Description of Examples) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows a control system of a constant speed traveling device according to an 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 equipped with a conventional type of intake system, and a throttle valve for controlling the amount of intake air into the combustion chamber is installed in an intake passage of this intake system. A throttle actuator 6 is provided to adjust the opening degree of this throttle valve. The vehicle 1 of this example includes a controller 7 that preferably includes a microcomputer, and the actuator 6 is actuated by a command signal from the controller 7. Further, the automatic transmission 3 is equipped with a gear position sensor 8 that detects the gear position in operation, and a signal indicating the detected gear position is input to the controller 7.

Further, the transmission 3 is equipped with a shift actuator 9 for selectively operating a predetermined gear stage, and this actuator 9 is adapted to be operated by a signal from the controller 7. In addition, the drive shaft 5
A vehicle speed sensor 10 that generates a pulse signal is attached to the controller 7, and a signal representing the vehicle speed from this vehicle speed sensor 10 is also input to the controller 7. Furthermore, the controller 7 receives signals from various switches given by the driver's operations, namely an acceleration switch 11 for increasing the target vehicle speed, a deceleration switch 12 for decreasing the target vehicle speed, and a return signal for restarting constant speed driving control. switch 13, main switch 14 that is turned on when performing constant speed driving control;
Signals are sent from the brake switch 15 for canceling the constant speed cruise control when a braking operation is performed, and from the transmission switch 16 for canceling the constant speed cruise control when the automatic transmission 3 is in neutral. Man-powered.

The controller 7 includes a switch input circuit 17 that receives signals from the various switches described above, a vehicle speed detection means 18 that calculates the actual speed of the vehicle, and an operation amount when the accelerator pedal 19 is operated, that is, the accelerator opening position. an accelerator position detection means 20 for detecting the accelerator position detection means, a basic throttle opening calculation means 21 for calculating the basic throttle opening based on a signal from the accelerator position detection means or a signal representing the vehicle speed deviation, and a slope detection means for detecting the slope of the road surface. means 22, a target vehicle speed setting circuit 23 for setting a target vehicle speed based on signals from the switch input circuit 17 and vehicle speed detection means 18; A running resistance prediction means 24 for predicting running resistance, a target vehicle speed setting circuit 23, and a vehicle speed detection means 18.
The target driving force calculating means 25 calculates the target driving force of the vehicle based on signals from the automatic transmission. A gear change determination means 26 for determining an appropriate gear position is provided.

Further, the controller 7 determines the final throttle opening control amount necessary for constant speed driving control based on signals from the vehicle speed detecting means 18, the traveling resistance predicting means 24, the target driving force calculating means 25, and the shift determining means 26. The final throttle opening calculation means 27 is provided, and a signal from the final throttle opening calculation means 27 is outputted to the throttle actuator 6 via the throttle opening control means 28.

Further, the controller 7 includes a shift control means 29 that controls the gear position of the automatic transmission based on the signal from the shift determination means, and the signal from the shift control means 29 is inputted to the shift actuator 6. ing.

The controller 7 also includes a target air-fuel ratio calculation means 30 that calculates a target air-fuel ratio based on the signals from the running resistance prediction means 24 and the target driving force calculation means 25. The signal is input to the injection correction means 31, and the fuel injection correction means 31 outputs a command signal to the fuel injection means 32 to prohibit power enrichment. Further, the signal from the throttle opening control means 28 is transmitted to the slope detection means 22 and the shift determination means 2.
6 is now also man-powered.

The control of this example will be explained below.

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

The controller 7 first initializes the system and switches the vehicle speed sensor 10, gear position sensor 8, accelerator pedal 19, acceleration switch 11, deceleration switch 12, return switch 13, main switch 14, brake switch 15, transmission switch 16, etc. The signals are read and A/D conversion is performed on these signals. Next, the controller 7: The accelerator position signal A/D converted by the accelerator position detecting means 20 is processed by the basic throttle opening calculating means 21 to calculate the basic throttle opening (THOB).
JB) is calculated.

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

Then, the basic throttle opening amount (TIIOBJB) is compared with the throttle opening amount for constant speed cruise control (THASC), and if the throttle opening amount (TIIASC) is large, the throttle opening amount (TIIASC) is changed to the target throttle opening amount. (THOBJ) to perform throttle control, and when the basic throttle opening (THOBJB) is large, the basic throttle opening (THOBJB) is set to the target throttle opening (THOBJ) and throttle control is performed.

Next, to explain constant speed running control, in FIG. constant-speed running control is performed when the switch is on and the deceleration switch 12 or the acceleration switch 11 is not being operated.

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

Furthermore, when the acceleration switch 11 is operated, the controller 7 increases the target vehicle speed (VSOBJ) by a fixed value each time the acceleration switch 11 is operated, and when the deceleration switch 12 is operated, the controller 7 increases the target vehicle speed (VSOBJ) by a fixed value every time the acceleration switch 11 is operated. decrease only. Furthermore, when the return switch 13 is operated, the memorized vehicle speed (MRVS) stored in a predetermined memory is set to the target vehicle speed (VSOBJ) and constant speed running control is started.

Next, the controller 7 calculates the road surface slope by executing the subroutine shown in FIG. 6 at each timer setting time.

Next, a constant speed running control routine, which will be described below, is executed every predetermined time period. That is, when a predetermined period of 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 (VSOBJ).
The deviation between the target vehicle speed (VSOBJ) and the target vehicle speed (VSOBJ)
DEFVS) is calculated.

When the vehicle speed deviation (DEFVS) exceeds a predetermined value, in this example, 15 km/h, constant speed driving control is stopped and the constant speed driving control throttle opening amount (T) is
IASC), the target vehicle speed (VSOBJ) and the integral element parameter (WKINT) are initialized.

If the vehicle speed deviation (DEFVS) is within 15 km/h, a proportional element (P) for calculating the final target driving force (TROBJ) is calculated. In this case, the proportional element (P) is obtained by multiplying the vehicle speed deviation (DEFVS) by predetermined proportional data (DP). Next, set the target vehicle speed (V
When the actual vehicle speed (SOBJ) is greater than the actual vehicle speed < VSR), the proportional element (P) is added to the target driving force (TROBJ), and when the actual vehicle speed (VSR) is greater than the target vehicle speed (VSOBJ), the target driving force is (TROBJ), then the proportional element (
The current target driving force (TROBJ) is calculated by decreasing P).
) to be corrected.

Next, the controller 7 outputs the final target driving force (TROBJ
) from the integral data (DI) to calculate the integral element (
+) is calculated. Similarly to the above proportional control, when the target vehicle speed (VSOBJ) is greater than the actual vehicle speed (VSR), the integral element parameter (WKINT) is set to the integral element (
1) and the actual vehicle speed (VSR) becomes the target vehicle speed (VSOBJ).
) If the yaw is also large, the integral element parameter (WKI
The current target driving force (TROBJ) is corrected by subtracting the integral element (1) from the current target driving force (TROBJ).

Next, since the power transmission efficiency changes depending on the oil temperature for the automatic transmission, the controller 7 calculates a correction coefficient of 0 to increase the target driving force (TROBJ) as the oil temperature is lower, and sets the correction coefficient to 0. 0 is the target driving force (TRO
BJ) to correct this.

Next, the controller 7 uses the road surface slope obtained from the subroutine shown in FIG. 6 and the actual vehicle speed (VSI'l) obtained from the subroutine shown in FIG. Predicted resistance (RL
OAD) further improves the target driving force (TROBJ).
is corrected to calculate the final target driving force (TROBJ).

Next, the controller 7 executes the gear change control subroutine shown in FIG. 8 to determine the optimum gear position (GPR) of the automatic transmission according to the current driving state of the vehicle.

Next, the controller 7 determines the throttle opening amount (T) for constant speed driving control based on the final target driving force (TROBJ), the actual vehicle speed (VSR), and the optimum gear position (GPR) that have been violated in the above-mentioned procedure. Calculate. In this case, the controller 7 is equipped with a map for each gear stage that shows the relationship between the final target driving force (TROBJ), the actual vehicle speed (VSR), and the throttle opening amount for constant speed driving control (THASC). Using the map, the constant speed cruise control throttle opening amount (TIIASC) at the relevant gear stage is determined.

Throttle opening degree 1 for constant speed cruise control (THAsc) calculated by the constant speed cruise control subroutine of FIGS. 3 and 4
) is the target throttle opening (THOBJ) if the predetermined conditions are satisfied in the main routine of Figure 2.
The throttle opening control means, that is, the throttle actuator 6, controls the throttle opening so that the throttle opening converges to the constant speed cruise control throttle opening amount (TIIASC) by executing the interrupt routine shown in FIG. It will be done.

Next, a procedure for determining variables used in the constant speed cruise control subroutines shown in FIGS. 3 and 4 will be explained.

FIG. 5 shows a flowchart of an interrupt routine for determining the actual vehicle speed (VSR) of the vehicle. In calculating the actual vehicle speed (VSR), the controller 7
The pulse signal from the vehicle speed sensor 10 is read and the vehicle speed pulse period (VST) is measured. Next, the vehicle speed pulse period (VST) is averaged to calculate the actual vehicle speed (VSR).

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

In FIG. 6, the controller 7 calculates the average vehicle speed (VSE) for the past T seconds and the average throttle opening (THE) for the past T seconds. Next, the above average vehicle speed (VSE
) and the average throttle opening (THE), the average driving force (TRACE) during that time and the running resistance (RROAD) with no slope are determined.

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

The controller 7 also controls the vehicle speed change (VS
D) is calculated, and the speed change per unit time, that is, the average acceleration (ACCE) is determined.

Then, virtual acceleration (ACCV) and average acceleration (ACC
Divide the difference between E) by the gravitational acceleration to find the road slope (RAMP)
seek.

FIG. 7 shows a subroutine for determining the predicted vehicle resistance (RLOAD), target vehicle speed (VSOBJ), and stored vehicle speed (λIRVS).

In FIG. 7, the controller 7 stores the actual vehicle speed (VSR) obtained in FIG. 5 and the road surface gradient (RAM) obtained in FIG.
Based on P), the predicted running resistance (RLOA) is calculated using a map.
Find D). Next, the integral element parameter (WKIN
In addition to setting the initial value of T), the actual vehicle speed (VSR) is stored in a predetermined storage location as a memorized vehicle speed (MRVS). In addition, the vehicle speed value set by the driver is converted to the target vehicle speed (
VSOBJ).

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

In this routine, the controller 7 first detects the current gear position (GPR) based on a signal from the gear position sensor 8. Next, the controller 7 determines the maximum driving force (TRMAX) at each gear position from a map showing the relationship between the actual vehicle speed (VSR) and the maximum driving force (TRMAX) that can be exerted at each gear position (GPR). If the maximum driving force (TRMAX) of the gear position is smaller than the target driving force (TROBJ), it is impossible to maintain that gear position and secure the required driving force. A command signal is sent to the speed change control means, that is, the speed change actuator 9, to downshift.

Further, when the maximum driving force (TRMAX) of the gear position is larger than the target driving force (TROBJ), the controller 7 calculates the margin driving force (STR) at that gear position, that is, the maximum driving force (TRMAX) and the target drive force. Power (TRO)
BJ), 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 speed change actuator 9. Note that if the extra driving force is not sufficient, the gear position is not changed.

FIG. 9 shows a flowchart of the air-fuel ratio control subroutine. In this routine, the controller 7 uses a map to determine the target air-fuel ratio based on the values of the target driving force (TROBJ) and the actual vehicle speed (VSR). Find (AFOBJ).

Then, based on the value of this target air-fuel ratio (AFOBJ), it is determined whether the current operating state satisfies the power enrichment conditions. In this case, the controller 7 determines that the vehicle is in the power enriched region when the target air-fuel ratio (AFOBJ) is equal to or higher than a predetermined value.

However, in the control of this example, power enrichment is not performed when constant speed driving control is performed, so a power enrichment prohibition signal is sent to the fuel injection means.

As described above, in the constant speed driving control of this example, instead of simply controlling the throttle opening according to the vehicle speed deviation as in the conventional case, the throttle opening is first controlled according to the size of the vehicle speed deviation. The initial value of the amount, that is, the basic throttle opening is given, and then the target driving force is determined according to the driving condition, and the throttle opening is finally 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 driving control can be performed.

In the above-mentioned embodiment, when performing shift control, the maximum driving force of the relevant gear stage is compared with the target driving force, but it is also possible to perform shift control using other means. .

For example, FIG. 11 shows a flowchart of a speed change control subroutine when performing speed change control between third and fourth speeds with focus on throttle opening. In FIG. 11, when performing speed change control, the controller 7
determines the gear position, and if the current gear position is 3rd speed, determines whether the throttle opening is smaller than a predetermined value θ2, and if it is smaller than the predetermined value e2, causes the shift control means to shift up. Send a signal. Also, the predetermined value e2
If it is not smaller than '', it is assumed that there is insufficient margin for running in third gear, and the vehicle maintains third gear. When the current gear position is 4th gear, the throttle opening is set to a predetermined value e.
, and if it is larger than a predetermined value e1, it is determined that the driving force is insufficient and a shift down signal is output to the speed change control means.

[Brief explanation of drawings]

FIG. 1 is a control system diagram of a constant speed traveling device according to an embodiment of the present invention, FIG. 2 is a flowchart of a main routine of control using the device shown in FIG. 1, and FIGS. 3 and 4 are A flowchart of a subroutine for performing constant speed driving control according to an embodiment of the present invention, FIG. 5 is a flowchart of an interrupt routine for calculating the actual vehicle speed, and FIG. 6 is a subroutine for calculating the road surface gradient. flow chart,
FIG. 7 is a flowchart of a subroutine for calculating the vehicle's predicted running resistance, target vehicle speed, and memorized vehicle speed. FIG. The figure is a flowchart of an air-fuel ratio control subroutine for prohibiting power enrichment, FIG. 10 is a flowchart of a throttle opening control execution routine, and FIG. 2 is a flowchart of a speed change control subroutine. 1...Vehicle, 2...Engine, 3...
... Automatic transmission 5 ... Drive shaft, 6 ...
・・Throttle actuator 7・・・Controller, ・・・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. Figure 2 Main routine Figure 4 Figure 5 Figure 6 Subroutine Figure 7 Subroutine Subroutine diagram Figure 11

Claims (1)

[Claims] a throttle valve provided in an intake passage; an actuator for adjusting the opening degree of the throttle valve; a vehicle speed detection means for detecting the actual vehicle speed of the vehicle; a target vehicle speed setting means for setting a target vehicle speed of the vehicle; A deviation detection means for detecting a vehicle speed deviation from a target vehicle speed, a basic throttle opening setting means for setting a basic throttle opening for controlling a throttle valve based on the vehicle speed deviation from the deviation detection means, and a running state of the vehicle. a driving state detecting means for detecting a driving state, a target driving force calculating means for calculating a target driving force according to the output signals from the deviation detecting means and the driving state detecting means, and a target driving force calculating means for calculating the basic throttle opening according to the target driving force. a target throttle opening control amount calculation means for calculating a throttle opening control amount from the target throttle opening control amount calculation means, and actuating the actuator so that the actual vehicle speed converges to the target vehicle speed based on an output signal from the target throttle opening control amount calculation means. 1. A constant speed driving control device for an automobile, comprising: feedback control means for controlling a throttle opening degree by adjusting the throttle angle.