JPH0243653B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] 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 running on a slope when integrally correcting a set duty deviation. That is.

[Conventional technology]

A constant speed vehicle is a constant speed vehicle that allows the vehicle to travel at a constant speed even when the foot is off the accelerator pedal.
For example, the controller 1 having the circuit configuration shown in FIG. 6 is mounted as shown in FIG. Figure 5 is a mechanical diagram of each part necessary for constant speed running 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. 6, and is controlled by an output signal A from the controller 1. The inputs of the control device 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, 10'. There is a cancel signal D etc. from .

Figure 6 is a block diagram of the analog control device 1. 19 is an F-V converter that converts the frequency (F) of the vehicle speed signal (pulse train whose period changes depending on the vehicle speed) C into voltage (V). be. The output of this converter 19 is not completely a direct current shunt, 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 average voltage is
This corresponds to the vehicle speed at the time when 0 is turned on, and thereafter becomes the control target (set vehicle speed) for constant speed driving. In other words, the output of the memory 21 (average voltage equivalent to constant vehicle speed) becomes the reference voltage of the comparator 22, and is used as the reference voltage of the F-V converter 1 thereafter.
9 (voltage corresponding to actual vehicle speed at each point in time). When the difference between the two inputs of the comparator 22 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, the opening degree of the control valve driven by the coil 17 is proportional to the duty. This control valve is the accelerator pedal 4
Similarly, the accelerator link 15 is driven to change the opening degree of the throttle 3. The output of the comparator 22 is supplied to the lead angle compensation circuit 23, the inhibition gate 24, and the driver 25.
is applied to the coil 17 through. The advance angle compensation circuit 23 compensates for system delays mainly caused by mechanical operation delays of the actuator 16. Prohibition gate 24
is opened only when traveling at a constant speed to allow 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. 7a 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 seventh
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 the inconvenience of moving from SV to SV' on the straight line _C2 . Therefore, as shown in FIG. 6, 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 in operation, if the vehicle approaches a slope while traveling at a constant speed, the subsequent vehicle speed may suddenly change. for example,
Since the vehicle speed tends to decrease on an uphill road, the average value of the duty increases to compensate for this and keep the vehicle running at a constant speed. There is no problem if you can move to a flat road in that state, but the set deviation integral correction function described above cannot distinguish whether the increase in the average duty value is due to an uphill road or not, so it is uniformly treated as a set deviation and is reduced. The set duty is corrected in this way. The correction in this case is shown in Figure 7b.
Since the direction is from SD to SD′, it is as if the set vehicle speed was increased from SV′ to SV.
As a result, there is a risk of sudden acceleration when transitioning from an uphill road to a flat road. On the other hand, when moving from a downhill road to a flat road, there is a risk of sudden deceleration. 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. In a constant speed driving device for an automobile having a set duty correction means for correcting a set duty value, a slope angle sensor detects the slope angle of a slope, and a driving period during which the slope slope exceeds a predetermined value is determined based on the output of the slope angle sensor. The present invention is characterized in that a set duty correction prohibiting means is provided for prohibiting the operation of the set duty correcting means during a period of time.

[Function] If a slope detection sensor is installed in a car, and the output of the sensor detects running on a slope exceeding a predetermined inclination angle, and the integration of the set deviation is interrupted during the period of running on the slope, it is possible to detect the slope after the transition to a flat road. can prevent sudden changes in vehicle speed. This will be explained in detail below with reference to illustrated embodiments.

〔Example〕

FIG. 1 is an explanatory diagram showing an embodiment of the present invention using a sensor for detecting engine negative pressure as a slope detection sensor, and shows the relationship between slope running and an integration stop period. The negative pressure sensor 50 is attached to a negative pressure introduction pipe 51 to the actuator 16, for example, as shown in FIG. Let E occur. Then, the output E of this sensor 50 is inputted to an integration circuit 40 as shown in FIG. 6 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 output E of the sensor 50 turns on (on a slope) during this sampling period, the integration is temporarily stopped, and after the output E turns off (on a flat road), the integration is restarted. Therefore, in the example of FIG. 1, the sampling period is divided into T=T ₁ +T ₂ +T ₃ , and the hill running period in between is excluded. This prevents the vehicle speed from suddenly changing after transitioning to a flat road.

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 microphone computer. 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 samples. In addition, the output E of the negative pressure sensor 50 includes one that turns on at a reference negative pressure a (for example, -150 mmHg) or lower when climbing a hill, and one that turns on at a reference negative pressure b (for example, -400 to -400 mmHg when going downhill).
There are two systems, one that turns on at -500 mmHg) or higher, and the program identifies these separately, but the same is true for one system of output E as shown in Figure 1. In this case, the negative pressure c on a flat road is approximately -300mmHg
It is assumed that the

FIG. 3 is an explanatory diagram of another embodiment of the present invention using an inclination sensor as the slope detection sensor, and FIG. 4 is a flowchart when this is realized by a microcomputer. The tilt angle sensor is mounted on a part of the automobile, for example as shown in 60 in FIG. 5, and its detection output E is inputted to the controller 1. This inclination sensor 60 generates a detection output E when the actual slope exceeds +a% or when the slope falls down over -a% (a is the reference slope). In this way, this example and the previous example are the same except for the slope detection sensor.

〔Effect of the invention〕

As described above, according to the present invention, in a constant speed driving system for an automobile that performs duty control on the throttle opening degree and integrally corrects the set deviation of the set duty, the accumulation of the set deviation is interrupted when driving on a slope. This has the advantage of preventing erroneous control in which the vehicle speed suddenly changes after returning to a flat state.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
FIG. 3 is an explanatory diagram showing another embodiment of the present invention, FIG. 4 is a flow chart thereof, and FIGS. 5 and 6 are structural diagrams showing an example of an automobile constant speed traveling device. The block diagram, FIG. 7, is an explanatory diagram of the set deviation. In the figure, 1 is a controller, 2 is an engine, 3 is a throttle, 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, 40 is an integrating circuit, and 50 is a The negative pressure sensor 60 is a tilt sensor.

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 slope angle sensor for detecting the slope angle of the slope, and a set duty correction prohibition means for prohibiting the operation of the set duty correction means during a running period in which the slope angle of the slope exceeds a predetermined value based on the output of the slope angle sensor. A constant speed traveling device for automobiles characterized by: