JPS6285732A - Vehicle speed controller - Google Patents

Abstract

PURPOSE:To enable quick reset to a control target speed by switching the speed change stage to the low speed side while resetting an integrated deviation of vehicle speed upon decision that the control target speed can not be maintained. CONSTITUTION:A vehicle speed controller comprises a deviation integrating means 5 for integrating the deviation between a control target speed set by a target vehicle speed setting means 3 and an actual vehicle speed detected through a vehicle speed sensor while a control circuit 7 for providing a drive signal corresponding with the integrated deviation to a throttle actuator 1 is provided. Here, the control circuit 7 is provided with means 11 for deciding such condition as the control target speed can not be maintained at least on the basis of the control target speed and the actual vehicle speed. Upon reception of a signal informing that the control target speed can not be maintained, a shift-down command is provided from a speed change command means 13 to an automatic speed change controller 9 while a reset command signal is provided from a reset command means 15 to the deviation integrating means 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle speed control device that automatically causes a vehicle equipped with an automatic transmission control device to travel at a controlled target vehicle speed.

[Prior Art] Conventionally, a vehicle speed control device generally includes an actuator, that is, a throttle actuator, which is driven by the negative pressure in the engine intake passage, and a control circuit, that is, a target vehicle speed setting means for determining a control target vehicle speed. The control circuit has a deviation integrating means for integrating the deviation between the control target vehicle speed and the actual vehicle speed, and a control circuit that outputs a drive signal corresponding to at least the integrated deviation value by the deviation integrating means to the throttle actuator.

[Problems to be Solved by the Invention] However, according to such a vehicle speed control device,
When driving on a relatively steep uphill or downhill slope, the medium speed is controlled.
There is a problem in that the vehicle speed may deviate greatly from the vehicle speed.

The present invention aims to solve this problem, and aims to prevent the vehicle speed from deviating significantly from the control target vehicle speed even when traveling on a relatively steep uphill or downhill slope.

[Means for Solving the Problems 1] To achieve this object, the vehicle speed control device of the present invention, as shown in FIG. 1, includes a throttle actuator 1 whose driving source is engine intake negative pressure, and It has a target vehicle speed setting means 3 that determines a control target vehicle speed, and a deviation integration means 5 that integrates the deviation between the control target vehicle speed and the actual vehicle speed, and the throttle actuator 1 is provided with at least the deviation integral value by the deviation integration means 5. In a device for controlling the running speed of a vehicle equipped with an automatic transmission control device 9, which includes a control circuit 7 that outputs a corresponding drive signal, the control circuit 7 is provided with a control circuit 7 based on at least a control target vehicle speed and a vehicle speed. or determining means 11 for determining whether the controlled target vehicle speed cannot be maintained based on variables in place of these; and upon receiving a signal from the determining means 11 to the effect that the controlled target vehicle speed cannot be maintained, the automatic shift control a shift command means 13 that sends a downshift command signal to change to the side gear; and a reset command means 15 that sends a heliset command signal to the deviation integration means 5 when receiving the negative signal from the determination means 11; It is characterized by providing the following.

[Operation] In this way, when it is determined that the control target vehicle speed cannot be maintained, the gear stage is switched to the lower speed side and the deviation integral value is reset, making it possible to quickly return to the control target vehicle speed.

[Example] The present invention will be described below with reference to FIGS. 2 to 9.

In FIG. 2, the throttle actuator 1 has a case 1-1 divided into two parts by a diaphragm 1-2. One chamber 1-3 includes a release valve 1-5 that opens and closes an opening 1-4 communicating with the atmosphere, and a negative pressure inlet 1 communicating with the other opening 1-6 communicating with the atmosphere and an engine intake passage 17. A control valve 1-8 that alternately opens and closes the diaphragm 1-7 and a spring 1-10 that biases the diaphragm 1-2 in the direction of the other diaphragm 1-9, that is, in the right direction in the figure, are built in. The other chamber 1-9 is provided with an arbitrary number of openings 1-11 which communicate with the atmosphere and are always open.
12 is accommodated, and the rod 1-12 moves in a linear direction in response to the displacement of the diaphragm 1-2, and adjusts the opening of the throttle valve 19 in the engine intake passage 17 via an accelerator link (not shown) or the like. Adjust.

In the release valve 1-5, during speed control, the drive coil 1-5a is kept energized by the control circuit 7, and the opening 1-4 communicating with the atmosphere is kept closed. That is, the release valve 1-5 is maintained in the state shown in the figure during speed control.

In the control valve 1-8, during speed control, a pulse current having a duty ratio determined by the control circuit 7 flows through the drive coil 1-88, and when the current is applied, the opening 1-6 communicating with the atmosphere is in a closed state and negative pressure is applied. The inlet 1-7 is in an open state, while the opening 1-6 is in an open state and the negative pressure inlet 1-7 is in a closed state when electricity is not supplied.

The control circuit 7 has functional blocks as shown in the following (1) to (7).

(1) When a speed control instruction is given, a target vehicle speed setting means 3° sets the vehicle speed at this time as a control target vehicle speed based on the output signal of the vehicle speed sensor 21. (2) Control target by this target vehicle speed setting means 3 Numbing means 23° for calculating the deviation between the vehicle speed and the actual vehicle speed (3) Deviation integrating means 5° for integrating the deviation by this cylinder reducing means 23 (4) Integrating the deviation integral value by this deviation integrating means 5, the vehicle speed, and the throttle opening The optimum regulator 27° outputs a control valve drive signal corresponding to these variables based on the throttle opening degree determined by the output signal of the degree detection means 25. (5) An uphill slope where the deviation between the control target vehicle speed and the actual vehicle speed is relatively steep. Or a determination means 11° for determining whether the road has reached a predetermined value as a downhill determination criterion or not, and whether the road has returned to a flat road from an uphill or downhill slope (6) This determination means 11 indicates that the road is uphill or downhill. When it receives the signal, it outputs a downshift command signal to the automatic transmission control device 9 to change the current gear to a lower gear by one gear, and also outputs a signal indicating that the road has returned to a flat road from an uphill or downhill slope. Upon receiving the signal from the determining means 11, the shift command means 13° outputs a shift up command signal. (7) When receiving a signal from the determining means 11 indicating that it is an uphill or downhill slope, the deviation integrating means 5 outputs the deviation up to that point. The reset command means 15°$1 ti11 circuit 7 which outputs a reset command signal for resetting the integral value performs processing as specifically shown in the flowchart of FIG.

Throttle opening degree θ(n) is detected from the output signal of throttle opening degree detection means 25 (step 101).

The current vehicle speed V(n) is calculated from the output signal of the vehicle speed sensor 21 (step 102).

It is determined whether or not the control +11 is to be started (step 103).

When it is determined that control is to be started (step 103), the current vehicle speed V(n) obtained in step 102 is set as the control target vehicle speed V (step 104),
Set the basic duty Do corresponding to V* (105
). Thereafter, it is determined that it is under control (step 106)
Each time, steps 101 and 102 are performed, and the following process is periodically repeated.

(1) Find the deviation S (n) between the control target vehicle speed V* and the current vehicle speed V(n) (step 107).

(2) (1) Integral value ZA (n
) as ZA (n) −ZA (n −1) +S (
n) Yori request (step 108).

(3) Perform processing for flag F1 (step 10
9). As is clear from the flowchart of FIG. 4 (steps 201 to 2o5) representing this process, this flag F1 is set to rOJ before control m+ starts, and the duty D(n) is 100%. Nevertheless, when it is first determined that the deviation 5(n) is greater than or equal to the positive speed difference vO as a criterion for a relatively steep uphill slope,
1" and is reset to rOJ again at the next processing.

(4) Perform processing for flag F2 <Step 11
0). As is clear from the flowchart of FIG. 5 (steps 301 to 306) representing this process, this flag F2 is set to rOJ before the start of control, and the duty D (n) is 0% and the throttle Opening degree θ
(Despite n > 0%, that is, full throttle, it is determined for the first time that the absolute value l5(n)l of the deviation S (n) is greater than or equal to the positive speed difference v1, which is the criterion for a relatively steep downhill slope. When this occurs, it is set to "1" and is reset to "O" again during the next processing.

(5) When it is determined that the flag F1 or F2 is "1" (step 111), the deviation integral value ZA(n) is reset (step 112), and a downshift command signal is sent to the automatic transmission control device 9. Output (step 11
3). On the other hand, if it is determined that both flags F1 and F2 are rOJ (step 111), the process moves to the next step 114 without resetting ZA (n) and outputting a downshift command.

(6) Perform processing for flag F3 (step 11
4). As is clear from the flowchart of FIG. 6 (steps 401 to 407) representing this process, this flag F3 is set to rOJ before the start of control, and the average value θ(n> When it is determined for the first time that the difference in throttle opening is 00 or more, which is the criterion for returning from an uphill road to a flat road, it is set to "1".
It will be reset to "0" again during the next processing.

(7) Perform processing for flag F4 (step 11
5). As is clear from the flowchart of FIG. 7 (steps 501 to 507) representing this process, this flag F4 is set to "○" before the start of control, and the average value θ( n) is set to "1" when it is determined for the first time that the throttle opening difference is 01 or more, which is the criterion for returning from a downhill to a flat road.
It will be reset to rOJ again during the next processing.

(8) Determine whether flag F3 or F4 is "1" (step 116).

(9) If it is determined that the flag F3 or F4 is "1", a shift up command signal is output to the automatic transmission control device 9 (step 117). On the other hand, F3 or F4 is “1”
”, the process proceeds to the next step 118 without outputting the shift-up command signal.

(10) Find the amount of deviation between the current vehicle speed V(n) and the reference speed Va, that is, the perturbation valve δV(n) (step 118
).

(11) The increment δD (n) of the control valve drive signal to be output with respect to the basic duty DO is expressed as δD
(n)=-1ZA (n)-Kz/9 (n>
−KaV(n) (step 119).

Here 1. 2. and 3 respectively show the optimal feedback gains derived from a dynamic model based on so-called modern control theory.

(12) The duty D(n) of the control valve drive signal to be output is determined by D (n ) - DO + δD(0), and the corresponding control valve drive signal is output (step 120).

In this way, when the control circuit 7 detects that the vehicle changes from running on a flat road to running on a relatively steep hill and the actual vehicle speed decreases by more than a predetermined value from the control target vehicle speed despite the duty being 100%, it shifts down. After outputting the command signal and resetting the deviation integral value, the driver shifts from uphill driving to flat road driving, and when it is detected that the average throttle opening value has decreased by more than a predetermined value from the maximum value of the average throttle opening value, the next time outputs a shift-up command signal. Figure 8 shows the relationship among the actual vehicle speed, throttle opening, duty, downshift command signal, upshift command signal, and reset command signal during the period from flat road driving to uphill driving and back to flat road driving. Illustrated.

Furthermore, when the control circuit 7 detects that the vehicle has shifted from running on a flat road to running down a relatively steep slope, and that the actual vehicle speed has increased by more than a predetermined value from the control target vehicle speed despite the duty being 0% and the throttle being fully open, After outputting the downshift command signal and resetting the deviation integral value, the system shifts from driving downhill to driving on a flat road, and when it is detected that the average throttle opening has increased by a predetermined value or more from the minimum average throttle opening. , this time outputs a shift-up command signal. Figure 9 shows the actual vehicle speed, throttle opening, duty, shift 1-down command signal, shift-up command signal, and reset command signal during the period from flat road driving to downhill driving and returning to flat road driving. illustrates the relationship.

Note that as a means of determining whether the control target vehicle speed cannot be maintained, the throttle opening is used instead of the vehicle speed as described above, and the target throttle opening and the actual throttle opening correspond to the control target vehicle speed on a one-to-one basis. It is also possible to determine the state based on the deviation from

[Effect 1 of the Invention As described above, according to the present invention, it is possible to maintain the 'rtI speed close to the control target vehicle speed even when traveling on a relatively steep uphill or downhill slope. Further, by resetting the deviation integral value, the duty is no longer set based on the cumulative error up to that point, so it can be expected that a preferable duty suitable for the driving condition will be set.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the present invention, Figs. 2 to 9 show an embodiment of the present invention, Fig. 2 is a block diagram, and Figs. 3 to 7 are for explaining the processing, respectively. The flowcharts in FIGS. 8 and 9 are explanatory diagrams mainly for explaining the control in uphill running and downhill running, respectively. 1... Throttle actuator 3... Target vehicle speed setting means 5... Deviation integration means 7... Control circuit 9... Automatic shift control device 11... Determination means 13... Shift command means 15.・Reset command means

Claims (1)

[Scope of Claims] 1. A throttle actuator driven by engine intake negative pressure, target vehicle speed setting means for determining a control target vehicle speed, and deviation integrating means for integrating the deviation between the control target vehicle speed and the actual vehicle speed. and a control circuit that outputs a drive signal corresponding to at least the deviation integral value by the deviation integrating means to the throttle actuator, and controlling the running speed of a vehicle equipped with an automatic transmission control device, the control circuit comprising: The circuit includes a determination means for determining whether the control target vehicle speed cannot be maintained based on at least the control target vehicle speed and the vehicle speed or a variable in place of these, and upon receiving a signal from the determination means indicating that the control target vehicle speed cannot be maintained. , a shift command means for transmitting a downshift command signal to the automatic shift control device to switch to a lower speed gear; and upon receiving a signal to that effect from the determination means, transmitting a reset command signal to the deviation integration means. A vehicle speed control device comprising: reset command means.