JPH0356928B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a speed control device for a vehicle that drives a speed adjustment element in relation to an actual vehicle speed and a target speed, and further includes means for receiving a speed increase command. The present invention relates to a device including speed increase control means for driving the speed adjustment element to the speed increase side while the speed increase signal generated in the above is generated.

[Background] A vehicle speed control device that enables speed increase control as described above is known, for example, from Japanese Patent Publication No. 51-30234. In this known device, since the actual speed as a result of speed increase is reset as the target speed, there is a problem in that the vehicle speed becomes excessive because there is no limit to how much the actual speed can be increased. . Generally, in a control device that drives a speed adjusting element to maintain a vehicle speed at a target speed, a means for restricting the target speed from exceeding a certain limit speed is also provided. When considering the use of such a control means in combination with the above-mentioned known technology, it is possible to limit the actual speed so that it does not exceed the target speed during a speed increase command. In this case, if the speed increase is stopped when the actual speed reaches the limit speed, the actual speed will overshoot and the driving feeling will deteriorate.

[Objective] The present invention provides a speed control device for a vehicle that can increase the traveling speed according to a driver's operation during constant speed traveling control, and prevents the traveling speed of the vehicle from increasing excessively. It is an object of the present invention to provide a speed control device for a vehicle that can improve the feel of an acceleration operation during constant speed driving control.

〔composition〕

In order to achieve the above object, the present invention includes: a vehicle speed sensor that detects the traveling speed of a vehicle; an actuator that drives a speed adjustment element of the vehicle in accordance with a drive signal; and a vehicle that matches the traveling speed of the vehicle to a target speed. control means for controlling constant speed travel by outputting the drive signal to the actuator so as to cause the actuator to perform constant speed travel control; an acceleration command signal output means for outputting a signal; and a speed increase control means for outputting a drive signal to the actuator to drive the speed adjustment element to the speed increase side when the acceleration command signal is output, A speed control device for a vehicle that performs constant-speed running control with the running speed at the time when the output of the command signal ends as a new target speed, comprising: a storage means for storing speed data related to a limit speed during constant-speed running; When the speed adjusting element is driven to the speed increasing side by the speed increasing control means, as the traveling speed of the vehicle approaches the limit speed, the stored speed data and the traveling speed of the vehicle increase. and a driving amount reducing means for reducing the driving amount of the speed adjusting element toward the speed increasing side based on the speed.

〔effect〕

According to the present invention, when the acceleration command signal is output during constant speed running control, the running speed of the vehicle is limited to a predetermined limit speed, so that the running speed does not increase excessively. can be prevented. Furthermore, as the traveling speed of the vehicle approaches the above-mentioned limit speed, the amount of drive of the speed regulating element toward the acceleration side is reduced, so that the speed when the traveling speed of the vehicle is limited to the above-mentioned limit vehicle speed is reduced. This makes it possible to prevent fluctuations in the speed and improve the feel of acceleration operations during constant speed driving control.

[Example] Hereinafter, the present invention will be described with reference to two embodiments, which differ in how the speed increase control amount is determined. In any of the embodiments, the limit speed setting means has a fixed limit speed set in advance, but the limit speed can be varied manually or by an external command signal such as wireless. You can also use it as

In FIG. 1, a vacuum-type speed regulating element 1 is connected in a known manner to a carburetor throttle valve 2 of an internal combustion engine as a vehicle prime mover. The speed control elements 1 each include a relief valve 3 of an electromagnetically actuated type.
and a control valve 4. The control valve 4 is configured to be electromagnetically actuated in response to the control signal S2, and adjusts the air pressure in the pressure chamber by alternately connecting and disconnecting the atmosphere and the negative pressure in the intake pipe, thereby displacing the throttle valve 2. The relief valve 3 is normally open and opens the pressure chamber to the atmosphere, but
It closes when energized by an electrical signal, allowing the control valve 4 to adjust the air pressure within the pressure chamber.

The control circuit 5 determines the control mode based on command signals S3 and S4 generated by operating the speed increase command switch 6 and the cancel command switch 7, and determines whether to energize or deenergize the control signal S1 to the relief valve 3. Based on the actual speed data and target speed data generated from the signals from the vehicle speed sensor 8, which generates a pulse train signal corresponding to the actual speed of the vehicle, and the internally preset limit speed data, the control valve 4 is controlled. The intermittent ratio of energization and deenergization of the control signal S2 is changed. When the speed increase command switch 6 is operated, the intermittent ratio is changed to the speed increase side to increase the vehicle speed, and when the operation of the speed increase command switch 6 is stopped, the actual speed at that time is controlled as the target speed. It is set to circuit 5. Therefore, if the speed increase command switch 6 is operated with a single touch, no speed increase will actually occur and the actual speed at that time will be set as the target speed. However, a known set switch may be provided separately from the speed increase command switch 6.

The control circuit 5 is constructed using a microcomputer and peripheral circuits commonly used for coupling input/output devices, and an outline of a control program that defines the operation of the microcomputer is shown in FIG. The microcomputer includes a ROM that stores a control program and control constants, and the ROM also has a memory address 5A in which a limit speed is set in advance. Next, the operation of this device will be explained with reference to FIG.

Now, when power is started to be supplied to the apparatus by turning on a main switch (not shown), the computer 5 starts executing the control program, performs an initialization process in step 11, and starts processing a circulation process routine in step 12.

In step 11, it is determined whether speed control is being performed. This determination is made based on the operation status of switches 6 and 7, which are periodically checked by a timer interrupt program (not shown).
This is done by referring to the flag to be reset. In addition, in the interrupt program, switch 6
When an operating signal is generated in the switch 7, a flag is set, and the flag indicating that an operating signal is generated in the switch 7 is reset.

If the control is not in progress, in step 17, the control signal S1 for the relief valve 3 is set to a de-energizing level to reduce the suction ability of the throttle valve 2 by the speed regulating element 1 as a cancel process. If it is under control, it is determined in step 12 whether speed increase control is under way.
This determination is made based on whether or not there is an operation signal generated at the speed increase command switch 6.

If a speed increase operation signal is generated, limit speed data previously set in storage address 5A of the internal memory (ROM) is stored as target speed data in step 18. After this step 14 is executed. Step 14 is known per se, and is based on the actual speed data calculated on the basis of the pulse train signal obtained from the vehicle speed sensor 8 and the target speed data. The intermittent ratio of the control signal S2 to be applied is determined and output. In this case, it is also possible to use a proportional differential control method that also takes into account changes in actual speed data over time, if necessary.

Therefore, when the speed increase command switch 6 is turned on, if the actual speed is sufficiently smaller than the limit speed, the intermittent ratio of the control signal S2 is introduced into the pressure chamber of the speed adjustment element 1 because the deviation between the two is large. By increasing the rate of vacuum applied to the vehicle, the vehicle speed can be increased sufficiently quickly. When the actual speed approaches the limit speed, the deviation between the two becomes smaller, and the intermittent ratio of the control signal S2 gradually decreases the proportion of the negative pressure introduced to slow the approach speed to the limit speed. can.

When the operation of the speed increase command switch 6 is stopped, the process moves from step 12 to step 15. In step 15, it is determined whether the speed increase command has just been stopped. For this purpose, the determination result at step 15 in the immediately previous program execution cycle may be stored.

If the speed increase command has just been stopped, in step 16, the latest actual speed data calculated at that time is stored as target speed data. After this, step 14 is executed, and the intermittent ratio of the control signal S2 is calculated so as to maintain the vehicle speed at the time when the speed increase command was stopped as the target speed, and is output to the speed adjustment element 1.

FIG. 3 shows a second embodiment in which the program step 13 for determining the control amount during speed increase control is modified from the above embodiments.

In FIG. 3, step 13A is a process for calculating the intermittent ratio of the control signal S2 during speed increase control, and step 14A is a process for calculating the intermittent ratio during normal control. Calculation of the intermittent ratio in step 14A is performed in the same manner as in step 14 in the previous embodiment, and only output processing 14B is programmed to be common from step 13A onwards.

Now, in step 13A, the intermittent ratio D is calculated based on the following equation.

D=Dmax-K(Sp-Spo) Note that Dmax is preset at the maximum value to which the speed adjustment element 1 can respond. Sp is actual speed, Spo
is a predetermined speed lower than the limit speed (Sp max), for example, 5
It is assumed that the microcomputer stores this threshold speed data Spo in memory address 5A instead of the limit speed at a threshold speed set to be smaller by Km/h. K is a proportionality constant.

According to this control program, the intermittent ratio given to the speed adjustment element 1 during the speed increase command is as follows:
When the actual speed Sp is less than the threshold speed Spo, the value becomes larger than the maximum value Dmax (exceeding the maximum value Dmax is essentially invalid), and the speed control element 1 suddenly opens the throttle valve 2 to control the speed of the vehicle. Increase speed. However, the vehicle speed is below the threshold speed.
When Spo is reached, the intermittent ratio is decreased by a value proportional to the amount exceeding the threshold speed Spo, and the throttle valve 2
Shifts the opening degree in the closing direction to suppress the amount of speed increase of the vehicle. Also in this embodiment, the vehicle speed during the speed increase command does not exceed the threshold speed by much.

Note that the maximum value D max of the intermittent ratio is not limited to the value that makes the throttle valve 2 open to the maximum degree, but may be set to an appropriate value below that value.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
This figure is a flowchart showing a first example of a control program for a microcomputer applied to the configuration of FIG. 1, and FIG. 3 is a flowchart showing a second example of a control program. DESCRIPTION OF SYMBOLS 1... Speed adjustment element, 5... Control circuit, 5A... Memory address forming setting means, 6... Speed increase command switch, 1
3, 13A...Program step forming speed increase control means.

Claims (1)

[Scope of Claims] 1. A vehicle speed sensor that detects the traveling speed of a vehicle; an actuator that drives a speed adjustment element of the vehicle in accordance with a drive signal; and an actuator that adjusts the traveling speed of the vehicle to match a target speed. a control unit that outputs the drive signal to perform constant speed driving control; and an acceleration unit that outputs an acceleration command signal in response to a driver's operation when the constant speed driving control is performed by the control unit. a command signal output means; and a speed increase control means for outputting a drive signal to the actuator to drive the speed adjustment element to the speed increase side when the acceleration command signal is output, the output of the acceleration command signal is A speed control device for a vehicle that performs constant speed driving control with the current driving speed as a new target speed, comprising: a storage means for storing speed data related to a limit vehicle speed during constant speed driving; and the speed increasing control means. Therefore, when the speed adjusting element is being driven to the speed increasing side, as the traveling speed of the vehicle approaches the limit speed, the speed adjustment element is driven to the speed increasing side, and as the traveling speed of the vehicle approaches the limit speed, the A speed control device for a vehicle, comprising: a driving amount reducing means for reducing the driving amount of the speed adjusting element toward the speed increasing side.