JPS62231830A - Constant speed travel control device for automobile - Google Patents

Abstract

PURPOSE:To always enable constant speed travel control with good convergence by providing a throttle opening operating means for operating the opening of a throttle valve in accordance with a signal from a target driving force correcting means and controlling a throttle opening so that an actual vehicle speed converges into 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 the final throttle opening controlled variable based on signals from a vehicle speed detecting means 18, a traveling resistance estimating means 24, the target driving force operating means 25, and a speed change judging means 26. Thereby, a driving force which is necessary for attaining the target vehicle speed is obtained while correcting the driving force considering a road face gradient, etc., to calculate the final target driving force, and based on this value, the throttle opening is controlled. Accordingly, a constant speed control with an always good convergence can be carried out irrespective of change in road surface gradient, etc.

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, The vehicle is equipped with 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, and 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, thereby converging the actual vehicle speed to the target vehicle speed. However, even if the magnitude of the vehicle speed deviation is the same, the magnitude of the running resistance will differ if the vehicle running conditions such as the slope of the road surface and the road surface resistance are different, so the amount of running resistance required to reach the target vehicle speed will differ. The output, that is, the driving force will differ. For this reason, the required throttle opening control amount also changes depending on the driving condition, and 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 is not suitable for reaching the target vehicle speed. The problem is that good convergence cannot be obtained.

(Means for Solving the Problems) The present invention was constructed in view of the above circumstances, and it is possible to stably and quickly converge to a set target vehicle speed even if the driving state of the vehicle differs. The purpose of the present invention is to provide a constant speed driving device for automobiles.

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;
driving condition detection means for detecting at least the slope of the road surface;
a target driving force calculation means for calculating a target driving force according to an output signal from the deviation detection means; a target driving force correction means for correcting a value of the target driving force according to an output from the running state detection means; a throttle opening calculation means for calculating the opening of the throttle valve according to a signal from the target driving force correction means; and a throttle opening calculation means for calculating the opening of the throttle valve according to a signal from the target driving force correction means; 7) Feedback control means for controlling the throttle opening degree by operating the actuator.

According to the present invention, first, the vehicle speed deviation between the actual vehicle speed and the target vehicle speed is determined, and then the target driving force is calculated according to the magnitude of this vehicle speed deviation and the actual vehicle speed. This basic target driving force value is then corrected by taking into account the driving conditions of the vehicle, such as the slope of the road surface, road resistance, etc., and the final target driving force required to make the vehicle reach the target speed is determined. It will be done. The opening degree of the throttle valve is determined according to the magnitude of this driving force, and the opening degree of the throttle valve is controlled via an actuator.

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. The throttle opening control amount is determined based on the final target driving force obtained by correcting the driving force value obtained from the map in consideration of driving conditions such as road surface slope.

(Effect of the invention) In the conventional constant speed driving system, the throttle opening was simply controlled according to the size of the vehicle speed deviation, but when the driving condition such as the road surface gradient 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 determining the control amount of the throttle opening, the constant speed traveling device of the present invention does not simply determine the control amount based on the vehicle speed deviation, but also determines the driving force necessary to reach the target vehicle speed. This driving force is corrected by taking into account the road surface gradient, etc., the final target driving force is calculated according to the driving condition of the vehicle, and the throttle opening is controlled based on the value of this final target driving force. There is.

Therefore, in the constant speed driving control of the present invention, throttle opening control is performed in consideration of driving conditions such as road surface slope, so that rational constant speed driving with good convergence is always possible regardless of changes in road surface slope, etc. It becomes possible to perform control.

(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 manually input to the controller 7.

Furthermore, 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 vehicle speed sensor 10, and a signal representing the vehicle speed from this vehicle speed sensor 10 is also input manually 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. is input.

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 detecting means 20 for detecting the accelerator position, a basic throttle opening calculating means 21 for calculating the basic throttle opening based on the signal from the accelerator position detecting means, a slope detecting means 22 for detecting the slope of the road surface, and the above-mentioned switch input circuit. a target vehicle speed setting circuit 23 that sets a target vehicle speed based on signals from the vehicle speed detection means 17 and the vehicle speed detection means 18; a running resistance that predicts the running resistance of the vehicle based on signals from the target vehicle speed setting circuit 23 and the slope detection means 22; A target driving force calculating means 25 that calculates a target driving force of the vehicle based on signals from the predicting means 24, the target vehicle speed setting circuit 23, and the vehicle speed detecting means 18, the vehicle speed detecting means 18, the running resistance predicting means 24, and the target vehicle. Each of the automatic transmissions includes a shift determination means 26 that determines an appropriate gear stage of the automatic transmission based on a signal from the driving force calculation means 25.

Further, the controller 7 determines the final throttle opening control habit required for constant speed driving control based on signals from the vehicle speed detecting means 18, the running 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 manually 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 amount of fuel to be injected is manually corrected by the injection correction means 31, and the fuel injection correction means 31 outputs a command signal to the fuel injection means 32 to inject a predetermined amount of fuel. There is.

Further, 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 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 uses the accelerator position detecting means 20 to
/D converted accelerator position signal is calculated by basic throttle opening calculation means 21 to calculate basic throttle opening (TI(OB)
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 (TIIASC) required for constant speed cruise control.

Then, the basic throttle opening (THOBJB) and the throttle opening 1 for constant speed cruise control (THASC) are compared, and if the throttle opening 1 (THASC) is large, the throttle opening 1 (T)IAsc) When the basic throttle opening (THOBJB) is large, the basic throttle opening (THOBJB) is set to the target throttle opening (THOBJ) to perform throttle control. and perform throttle control.

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.

Further, when the acceleration switch 11 is operated, the controller 7 increases the target vehicle speed (VSOBJ) by a fixed value each time it 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 it is operated. decrease only. Further, 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 driving 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 (V
The deviation (Dε) between the target vehicle speed (VSOBJ) and the target vehicle speed (VSOBJ)
FVS) is calculated.

When the vehicle speed deviation (DεFVS) exceeds a predetermined value, in this example, 15 Km/h, the constant speed driving control is stopped and the constant speed driving control throttle opening amount (T1
1^SC), the target vehicle speed (VSOBJ) and the integral element parameter (WKINT) are initialized.

If the vehicle speed deviation (D8FVS) is within 15 m/h, the proportional element (P) for calculating the final target driving force (TROBJ) is calculated. In this case the proportional element (P)
is the vehicle speed deviation (DIEFVS) and the predetermined proportional data (D
P). Next, when the target vehicle speed (VSOBJ) is greater than the actual vehicle speed (VSR), a proportional element (P) is added to the target driving force (TROBJ'), and the actual vehicle speed (VSR) is greater than the target vehicle speed (VSOBJ). In this case, the current target driving force (TR
OBJ).

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 (WKINT) is added to the integral requirement parameter (WKINT).
1) and the actual vehicle speed (VSR) becomes the target vehicle speed (VSOBJ).
), the integral element parameter (WKIN
The current target driving force (TROBJ) is corrected by subtracting the integral element (1) from T).

Next, since the power transmission efficiency changes depending on the oil temperature for the automatic transmission, the controller 7 calculates 0 as a correction coefficient that increases the target driving force (T80BJ) as the oil temperature is lower, and sets this 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 (VSR) obtained from the subroutine shown in FIG. 5 to calculate the predicted vehicle resistance obtained from the interrupt subroutine shown in FIG. (RLOA
D), the target driving force (TROBJ) is further 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), actual vehicle speed (VSR), and optimum gear position (GPR) obtained 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 (THASC) at the relevant gear stage is determined.

Throttle opening amount for constant speed driving control (THASC) calculated by the constant speed driving control subroutine shown in FIGS.
) 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 (THASC) 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 (VSB) for the past T seconds and the average throttle opening (THE) for the past T seconds. Next, the above average vehicle speed (VSB
) and the average throttle opening (THE), the average driving force (TRACE) during that time and the running resistance (RROAD) with no gradient 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 calculate the road slope (RA!)
Find I P ).

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

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 memory vehicle speed (!, IRVs). Further, the vehicle speed value set by the driver is stored as a 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). Then, the maximum driving force (TRMAX) of the relevant gear
If TROBJ is smaller than the target driving force (TROBJ), it is impossible to maintain the gear position and secure the required driving force. Sends a command signal to go down.

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 (TR
OBJ), 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). (AFOBJ)
, find.

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, when performing constant speed running control, power enrichment is not performed, so a power enrichment prohibition signal is sent to the fuel injection means.

Therefore, in the control of this example, even if the engine is in an enriched region where an output shortage occurs, fuel increase control is not performed on the fuel injection means, and the insufficient output is compensated for by throttle opening control.

As described above, in the constant speed driving control of this example, the throttle opening is not simply controlled according to the vehicle speed deviation as in the past, but the target driving force is controlled according to the vehicle driving condition such as the road surface slope. Since the vehicle is controlled according to the magnitude of the target driving force, constant speed driving control with good convergence can be performed regardless of changes in the road surface slope, etc.

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 θ2, causes the shift control means to shift up. Send a signal. Also, the predetermined value e2
If it is not smaller than that, 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 θ1.
If it is larger than a predetermined value θ1, 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, 8...Gear position sensor, 9...
Speed change 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. Fig. 2 Main routine Fig. 9 Subroutine Subroutine Fig. 4 Fig. 5 Fig. 6 Subroutine Fig. 7 Subroutine Subroutine diagram Fig. 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 detecting means for detecting a vehicle speed deviation from a target vehicle speed; a driving state detecting means for detecting at least a slope of a road surface; and a target driving force calculating means for calculating a target driving force in accordance with an output signal from the deviation detecting means. , a target driving force correction means for correcting the value of the target driving force according to the output from the running state detection means, and a throttle opening calculation for calculating the opening degree of the throttle valve according to the signal from the target driving force correction means. and 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 throttle opening calculation means. Automobile constant speed driving control device.