JPH0236407B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a constant speed driving system for automobiles that duty-controls the throttle opening, and in particular aims to eliminate the influence of accelerator operation when integrally correcting a set duty deviation. That is.

[Conventional technology]

A constant speed vehicle drive system that allows the vehicle to travel at a constant speed with the foot off the accelerator pedal is
For example, the controller 1 having the circuit configuration shown in FIG. 4 is mounted as shown in FIG. 3. Figure 3 is a mechanical diagram of each part necessary for constant speed driving control, where 2 is the engine, 3 is the throttle, 4 is the accelerator pedal, 5 is the foot brake pedal, 6 is the brake lamp switch that detects the pedal depression, and 7 is the Clutch pedal; 8 is a clutch switch that detects depression of the pedal; 9 is a parking brake lever; 10 is a parking brake switch that detects operation of the lever; 1;
0' is a neutral start switch in the case of an automatic vehicle, 12 is a speedometer, 13 is a reed switch (vehicle speed sensor), and 14 is a chime.

The opening degree of the throttle 3 during normal driving can be changed by transmitting the amount of depression of the accelerator pedal 4 to the throttle 3 through the accelerator link 15, but when driving at a constant speed, the opening degree of the throttle 3 can be changed by an actuator 16 that uses engine negative pressure. . This actuator 16 includes a control valve coil 17 and a release valve coil 18 as shown in FIG. 4, and is controlled by an output signal A from the controller 1. The inputs of the controller 1 include a prohibition signal B from the chain 14, a vehicle speed signal C from the reed switch 13, a set/resume signal S/R from the constant speed operation switch 11, and switches 6, 8, 10, and 10'. There are cancel signals D, etc.

FIG. 4 is a block diagram of the analog controller 1, and 19 is an F-V that converts the frequency F of the vehicle speed signal (pulse train whose period changes depending on the vehicle speed) C into a voltage V.
It is a converter. The output of this converter 19 is not completely a DC component, but includes ripples depending on the period of the input pulse. When a switch 20 is turned on, the output of the converter 19 is led to an analog memory 21, in which an averaging function stores the average voltage over a predetermined period. This corresponds to the vehicle speed at the time when the average voltage switch 20 is turned on, and thereafter becomes the control target (set vehicle speed) for constant speed driving. That is, the output of the memory 21 (average voltage corresponding to the set vehicle speed) becomes the reference voltage of the comparator 22, and is compared with the output of the F-V converter 19 (voltage corresponding to the actual vehicle speed at each point in time) thereafter. Comparator 2
When the difference between the two inputs is small, the current flowing to the control valve coil 17 is turned on and off at the ripple frequency. In other words, the output of the comparator 22 is a pulse train, the duty of which changes depending on the difference between the set vehicle speed and the actual vehicle speed. Therefore, coil 1
The opening degree of the control valve driven by 7 is proportional to the duty. This control valve drives the accelerator link 15 in the same way as the accelerator pedal 4, and changes the opening degree of the throttle 3. The output of the comparator 22 is sent to the lead angle compensation circuit 2.
3, applied to the coil 17 through the inhibit gate 24 and the driver 25. The advance angle compensation circuit 23 compensates for system delays mainly caused by mechanical operation delays of the actuator 16. The prohibition gate 24 opens only when the vehicle is traveling at a constant speed and allows the output of the compensation circuit 23 to pass through.

26 is a self-holding circuit that memorizes the constant speed running state, and when the set switch 27 of the operating switch 11 is turned on, the gate 24 receives the set signal S.
open. This set signal S also has the function of temporarily turning on the aforementioned analog switch 20. However, in a high-speed running state where the prohibition signal B is generated from the train 14, the high-speed limiter circuit 29 operates to close the prohibition gate 30 and prohibit the transition to constant-speed running. The constant speed running state is canceled by the cancel signal D. This cancel signal D is applied to each of the brake, clutch, and parking switches 6,
In addition to turning on lights 8 and 10, this also includes blowing out the brake lamp fuse 31. The resume switch 28 of the operating switch 11 is turned on when the vehicle returns to the set vehicle speed in the memory 21 from this cancel state and travels at a constant speed. On the other hand, when the set switch 27 is turned on after the cancellation, constant speed driving at the newly set vehicle speed is started. 32 receives the output of the self-holding circuit 26 and connects the release valve coil 1
This is a driver that drives 8.

In a steady state where the actual vehicle speed and the set vehicle speed (set vehicle speed) match during constant speed driving control, the percentage of the comparator output duty (this is called the set duty SD) is a setting matter, and generally Set this to about 40%. FIG. 5a is an explanatory diagram of this, where SV is the set vehicle speed. Constant speed running control is performed as follows. For example, in a steady state, if the vehicle approaches a downhill slope and the actual vehicle speed increases as shown, control is performed to reduce the duty and throttle opening as shown. As a result, when the actual vehicle speed begins to decrease as shown, control is performed to increase the duty and throttle opening as shown. When the actual vehicle speed decreases due to an uphill slope, etc., the same control is performed on the left side of the set vehicle speed SV.
In the end, feedback control is performed so that the set duty SD becomes the center of attention.

[Problem that the invention seeks to solve]

By the way, the relationship between duty and actual vehicle speed is the fifth
It is not on straight line C ₁ in figure a, but on straight line C ₂ as in figure b.
If the set duty SD is fixedly set, the set vehicle speed will be on the straight line _C1 .
There is an inconvenience that SV′ is on the straight line C ₂ from SV. Therefore, as shown in FIG. 4, an integrating circuit 40 is provided to integrate the output of the gate 24 for a certain period of time (approximately 10 to 30 minutes), and the average value is superimposed on the output of the memory 21 to calculate the set deviation (set duty and actual value). There is a method to correct the difference between the average duty value and the average duty value. According to this method, the set duty shifts from SD to SD', and as a result, the set vehicle speed is corrected to SV on straight line _C2 .

However, since the above-mentioned integration circuit 40 is always active, if the accelerator is operated while the vehicle is running at a constant speed, the subsequent vehicle speed may change suddenly. For example, if the driver lightly presses the accelerator pedal even though constant speed driving control is in progress, the actual vehicle speed will be higher than the set vehicle speed (for example, the set vehicle speed
Assuming that the actual vehicle speed is 5 km/h higher than 80 km/h), only the set duty is changed (decreased) so that the actual vehicle speed is decelerated to the set vehicle speed by the above-mentioned set deviation integral correction function. Therefore, when the driver takes his foot off the accelerator pedal, the set duty decreases (in the example in Figure 5, SD'→SD
There is a drawback that the actual vehicle speed suddenly decreases from (80+5) Km/h to (80-5) Km/h depending on the direction (direction).
The present invention attempts to improve this point.

[Means for solving problems]

The present invention stores the actual vehicle speed during driving in a memory by operating a switch and uses it as the set vehicle speed for the constant speed driving target value, and converts the difference between the subsequent actual vehicle speed and the set vehicle speed into a duty to set the set vehicle speed. control means for duty-controlling the throttle opening so as to maintain the throttle opening;
When the actual vehicle speed and the set vehicle speed match, the average value of the deviation between the set duty, which is set in advance to be a predetermined value, and the actual duty obtained within a predetermined sampling period is calculated, and the set duty is calculated based on the average deviation. A constant speed traveling device for an automobile having a set duty correction means for correcting a value, a detection means for detecting that an accelerator pedal is being operated, and a detection means for detecting that the accelerator pedal is being operated. The present invention is characterized in that a set duty correction inhibiting means is provided for prohibiting the operation of the set duty correcting means for a period of time.

[Effect]

By attaching a switch to the accelerator pedal to detect whether or not it is depressed, and by interrupting the integration of the set deviation when the accelerator is operated, it is possible to prevent sudden changes in vehicle speed after the accelerator is operated. This will be explained in detail below with reference to illustrated embodiments.

〔Example〕

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and shows the relationship between the operation of the accelerator pedal and the integration suspension period. The operation of the accelerator pedal is detected, for example, by attaching an accelerator pedal switch 50 near the accelerator pedal 4 as shown in FIG. Then, the output E of this switch 50 is inputted to an integration circuit 40 as shown in FIG. 4 to control the integration period. As mentioned above, the integrating circuit 40 has a fixed sampling time T, and feeds back the average value of accumulated deviations during that time. When the accelerator pedal switch is turned on in the middle of this sampling period, the integration is temporarily stopped, and after the switch is turned off, the integration is restarted. Therefore, in the example of FIG. 1, the sampling period is T=
It is divided into T ₁ + T ₂ , and the accelerator operation period in between is excluded. This prevents the vehicle speed from suddenly changing after the accelerator operation is completed.

Although the above is based on the assumption that the controller 1 is of an analog type, FIG. 2 shows a flowchart in the case of a microcomputer. In this case, unlike the analog method, the set deviation is sampled and accumulated a plurality of times within a predetermined sampling time T, so the average deviation is the value obtained by dividing the cumulative deviation by the number of sampling times.

〔Effect of the invention〕

As described above, according to the present invention, in the constant speed driving system for automobiles which duty-controls the throttle opening degree and integrally corrects the set deviation of the set duty, the accumulation of the set deviation is interrupted when the accelerator is operated. This has the advantage that the vehicle speed that changes as a result of accelerator operation does not affect the set deviation correction, and erroneous control in which the vehicle speed suddenly changes after the accelerator is returned can be prevented.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
The figure is a flowchart, FIGS. 3 and 4 are structural and block diagrams showing an example of a constant speed vehicle running system, and FIG. 5 is an explanatory diagram of set deviation. In the figure, 1 is a controller, 2 is an engine, 3 is a throttle, 4 is an accelerator pedal, 11 is a constant speed driving operation switch, 13 is a vehicle speed sensor, 16 is an actuator, 21 is an analog memory, 22 is a comparator, 4
0 is an integrating circuit, and 50 is an accelerator pedal switch.

Claims (1)

[Claims] 1 The actual vehicle speed during driving is stored in the memory by a switch operation and used as the set vehicle speed of the constant speed driving target value, and the difference between the actual vehicle speed and the set vehicle speed thereafter is converted into duty to maintain the set vehicle speed. control means for duty-controlling the throttle opening degree; and a control means for controlling the duty of the throttle opening, and a control means for controlling the deviation between the set duty, which is preset so that it becomes a predetermined value when the actual vehicle speed and the set vehicle speed match, and the actual duty obtained within a predetermined sampling period. A constant speed traveling device for an automobile having a set duty correction means for calculating an average value and correcting the set duty value based on the average deviation,
A detecting means for detecting that the accelerator pedal is being operated, and a set duty correction prohibiting means for prohibiting the operation of the set duty correcting means during a period in which the detecting means detects that the accelerator pedal is being operated are provided. A constant speed traveling device for automobiles characterized by: