JPH0211450B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed control device for a vehicle, and particularly to a vehicle speed control device for controlling a vehicle speed (constant speed target vehicle speed) during constant speed driving of a vehicle such as an automobile.
The present invention relates to a vehicle speed control device that performs control to increase speed and is capable of reducing as much as possible an overrun that occurs when transitioning from an accelerator mode to a constant speed mode.

In general, automobiles that perform autodrive (constant speed driving) are equipped with a speed control device that includes a built-in microcomputer, for example, and when the driver operates a set switch, the speed control device controls the current driving speed (vehicle speed ( The control vehicle speed data (set vehicle speed) is stored in the storage section, and the arithmetic processing section performs constant speed control processing based on the control vehicle speed data in the storage section, that is, the stored vehicle speed data, so that the automobile runs at a constant speed. Also, the speed control device is used to operate the accelerator switch (also called a resume switch) while driving at a constant speed.
When is operated, the arithmetic processing section performs acceleration processing of the vehicle while the accelerator instruction signal is being outputted, increasing the throttle valve opening and causing the traveling speed to gradually increase. During this time, the arithmetic processing section also rewrites the stored vehicle speed data in the storage section by sequentially rewriting the stored vehicle speed data with data corresponding to the traveling speed. Then, when the accelerator instruction signal is no longer output due to the accelerator switch off operation, constant speed control processing is performed based on the stored vehicle speed data at the time of completion of rewriting, and the vehicle is made to travel at a constant speed at the controlled vehicle speed after speed increase.

However, in automobiles equipped with this type of speed control device, even after the accelerator switch is turned off, the running speed continues to increase due to engine inertia, throttle actuator response delay, etc. The period from when the vehicle speed stabilizes to the controlled vehicle speed after the speed increase, that is, the transition period is relatively long. For this reason, for example, when operating the accelerator switch to reduce the distance between the vehicle in front and the vehicle in front to a desired distance, the driver must fully understand the above-mentioned characteristics of the vehicle and decide when to turn off the accelerator switch. Therefore, it requires skill to operate. Further, if the accelerator switch is operated by a person who does not understand the above-mentioned characteristics, the inter-vehicle distance may become narrower than necessary.

The present invention aims to solve the above points,
The purpose of the present invention is to make the above-mentioned transition period as short as possible to facilitate the driver's timing decision as described above, and to maintain safe driving. Therefore, the speed control device for a vehicle according to the present invention focuses on the fact that this type of vehicle is usually equipped with a well-known fuel injection control device, and actively instructs the fuel injection control device to cut fuel during the above-mentioned transition period. to cause engine braking. That is, the present invention includes a storage unit that stores controlled vehicle speed data based on the operation of a set switch, an accelerator switch that instructs acceleration processing of the vehicle by an accelerator instruction signal while driving at a constant speed based on the stored controlled vehicle speed data, Performing vehicle acceleration processing and rewriting the control vehicle speed data stored in the storage unit during a period in which the accelerator instruction signal is output, and when the accelerator instruction signal is no longer output, the rewriting is terminated; In a vehicle speed control device comprising an arithmetic processing unit that performs a constant speed control process using the control vehicle speed data at the end of the rewriting as a constant speed running target vehicle speed, at least the operation of the accelerator switch is released and the accelerator instruction is given. After the signal is no longer output, speed comparison means determines the magnitude of the constant speed target vehicle speed and the current vehicle speed, which is the actual vehicle travel speed input from the vehicle speed sensor, and the accelerator instruction signal is output. fuel cut instruction means for instructing the fuel injection control device to cut the fuel from the time when the current vehicle speed stops running until the time when the current vehicle speed is determined to be smaller than the constant speed target vehicle speed by the speed comparison means. It is characterized by: This will be explained below with reference to the drawings.

FIG. 1 is an example of the configuration of the main parts of a speed control system to which a conventional vehicle speed control device is applied, FIG. 2 is a flowchart for explaining its main processing operations, and FIG. 3 is for explaining the present invention. 4 shows the configuration of the main parts of a speed control system to which an embodiment of the vehicle speed control device according to the present invention is applied, and FIG. 5 shows a flow chart for explaining its main processing operations. There is.

In Fig. 1, numeral 1 is a speed control device which incorporates a microcomputer, a constant voltage circuit, a reset circuit, etc., and receives instruction signals a, b, and c from a set switch 2, an accelerator switch 3, and a brake switch 4, as well as a vehicle speed sensor. 5 outputs corresponding control signals e and f to the throttle actuator 6 based on the traveling speed signal d from the throttle actuator 5. Reference numeral 2 is a return type set switch, which is mainly operated when specifying constant speed driving, and 3 is an accelerator switch (also referred to as a stop switch), which is turned on when you want to increase the desired vehicle speed while driving at a constant speed. 4 is a brake switch that continues to be operated, and is switched as the brake pedal is operated; 5
6 is a reed switch type or photocoupler type vehicle speed sensor, which is disposed on the output shaft side of the transmission 7, and outputs a traveling speed signal d corresponding to the traveling speed; 6 is a throttle actuator, which controls the speed. Control signals e, f from device 1
7 is a transmission, 8 is a throttle valve, and 9 is an engine. respectively. An example of the processing operation will be described below with reference to the flowchart of FIG. 2.

When the main switch (not shown) is turned on while driving, power is supplied to the speed control device 1 from the battery (not shown), and the constant voltage circuit in the speed control device 1 A constant voltage is applied to the microcomputer and the reset circuit sets the microcomputer to a reset state, that is, an initial state.

The microcomputer is equipped with a storage section and an arithmetic processing section, and after the above initial settings, the arithmetic processing section repeatedly executes the following series of processes.

F-1 First, based on the set instruction signal a from the set switch 2, a set switch ON determination step is executed to determine whether or not the set switch 2 is turned on. Immediately after the main switch is turned on as described above, the set switch 2 has not been turned on yet, so the determination result is "NO" and the set switch ON determination step is executed again. Then, the set switch ON determination step is repeatedly executed until the set switch 2 is turned on and the determination result is reversed to "YES".

F-2 When set switch 2 is turned on,
The determination result is reversed to "YES" and the control vehicle speed storage step is executed. That is, vehicle speed data calculated based on the traveling speed signal d from the vehicle speed sensor 5, ie, control vehicle speed data, is written into the storage section.

F-3 Next, a control start processing step is executed, and the control signal e corresponding to the release valve is set to logic "1" level to close the release valve, and a flag instructing to start control is set.

F-4 Next, an accelerator switch ON determination step is executed based on the accelerator instruction signal b.

At this point, the accelerator switch has not been turned on yet, so the judgment result is "NO".
Then, the process moves to the next constant speed control processing step.

F-5 In the constant speed control processing step, the current vehicle speed data calculated based on the traveling speed signal d from the vehicle speed sensor 5 and the previous vehicle speed data calculated by the previous vehicle speed calculation process are used for 1.5 seconds, for example. Calculate the subsequent vehicle speed, that is, the predicted vehicle speed, compare the predicted vehicle speed data with the control vehicle speed data stored in F-2 above, and output a control signal f having a duty ratio corresponding to the comparison result to the control valve. Then, the negative pressure inside the diaphragm chamber is regulated to adjust the opening degree of the throttle valve 8.

F-6 Next, a cancel instruction signal presence determination step is executed based on the cancel instruction signal including the brake instruction signal c, and it is determined whether a cancel instruction signal is output from the brake switch 4 or the like. At this point, the determination result is "NO" and the above-mentioned accelerator switch ON determination step is executed again, and a closed loop consisting of the accelerator switch ON determination step, the constant speed control processing step, and the cancel instruction signal presence determination step is sequentially executed. . Therefore, the automobile runs at a constant vehicle speed corresponding to the control vehicle speed data written in the storage section.

F-7 During this closed loop execution, when the driver turns on the accelerator switch 3 in order to increase the desired vehicle speed, the judgment result from the accelerator switch ON judgment step is reversed to "YES",
The closed loop is canceled and the controlled vehicle speed storage step is now executed.

F-8 In the controlled vehicle speed storage step, the same process as the controlled vehicle speed storage step described above in F-2 is performed, and the controlled vehicle speed data written in the storage section in F-2 is stored as the controlled vehicle speed at the relevant point in time. Rewrite to data.

F-9 Next, execute the accelerator control processing step. That is, the control valve driving duty is unconditionally set to, for example, about 90%, and the opening degree of the throttle valve 8 is fixed and maintained at a sufficiently large value. Note that the accelerator control processing step may be a process of changing the duty according to the acceleration curve.

F-10 Next, the cancel instruction signal presence determination step is executed, and since the determination result is "NO", the accelerator switch ON determination step is executed again.

F-11 The judgment result from the accelerator switch ON judgment step is still “YES”, so
Next, a controlled vehicle speed storage step is executed to rewrite the controlled vehicle speed data, and an accelerator control processing step is executed to maintain the opening degree of the throttle valve still at a large value. Then, in the cancel instruction signal presence determination step, the determination result becomes "NO", and the accelerator switch ON determination step is executed again.

F-12 When the accelerator switch 3 is turned on in this way, each step of a closed loop consisting of an accelerator switch ON determination step, a controlled vehicle speed storage step, an accelerator control processing step, and a cancel instruction signal presence determination step is executed in sequence. Then, the control vehicle speed data is rewritten and the accelerator control process is performed.

F-13 Then, when the traveling speed increases to the desired traveling speed, that is, the desired vehicle speed, and the driver releases the ON operation of the accelerator switch 3, the determination result at the accelerator switch ON determination step is "NO".
The closed loop execution is canceled and the constant speed control process step is executed again.
However, this constant speed control processing step causes the vehicle to run at a constant speed based on the desired vehicle speed after speed increase.

F-14 When the driver operates the brake pedal while driving at a constant speed, brake switch 4
The brake instruction signal c of the logic "1" level is input from the brake control circuit 1, and the determination result of the cancel instruction signal presence determination step is inverted to "YES", and the cancel processing step is now executed. In this cancel processing step,
A process is performed to return the release valve, which has been closed in the control start process step, to an open state, that is, a process to return the control signal e to the logic "0" level.

Note that the cancel instruction signal is not limited to the brake instruction signal c as described above, but also includes various instruction signals caused by neutral operation, parking brake operation, and clutch operation (in the case of a manual vehicle).

F-15 Next, the set switch ON determination step is executed again, and the series of processes as described above in F-1 to F-14 are executed. Furthermore, if a cancel instruction signal is input before the accelerator switch is operated,
It goes without saying that the controlled vehicle speed storage step and the accelerator control processing step are not executed in this series of processing.

As mentioned above in F-1 to F-15, in conventional vehicle speed control devices, when the accelerator switch is released, constant speed control processing is started based on the control vehicle speed data at that point in time. . However, in reality, as is clear from the relationship between the operating state of the accelerator switch 3 and the vehicle speed as shown in FIG. The vehicle speed stabilizes at the desired vehicle speed after the vehicle speed increases relatively significantly as shown by the solid line in FIG. 3 due to the inertia of the engine 9 and the response delay of the throttle actuator 6.

The present invention suppresses the increase in vehicle speed as much as possible after the accelerator switch is released, and causes the vehicle speed to follow a trajectory as shown by the broken line in FIG.

FIG. 4 shows the configuration of the main parts of a speed control system to which the vehicle speed control device according to the present invention is applied, and FIG. 5 shows a flowchart for explaining its main processing operations.

In FIG. 4, 1' is a speed control device according to the present invention, and 10 is an existing fuel injection control device, which controls the amount of fuel to be supplied to the engine 9, the injection timing, etc. based on the engine 9 rotation speed, the engine 9 load, etc. What is controlled, g is a fuel cut request signal output from the speed control device 1' to the fuel injection control device 10, h is a control signal output from the fuel injection control device 10 to the engine 9, and other symbols are shown in FIG. The same reference numerals in each figure represent the corresponding elements.

An example of the processing operation will be described below with reference to the flowchart of FIG.

When the main switch (not shown) is turned on while driving, a constant voltage is applied to the microcomputer in the speed control device 1', and the microcomputer returns to the initial state, as in the case of the conventional example described above. is set.

The microcomputer is equipped with a storage section and an arithmetic processing section, and after the above initial settings, the arithmetic processing section repeatedly executes the following series of processes.

F'-1 First, only the set switch ON determination step is repeatedly executed until the set switch 2 is turned on.

F'-2 When the set switch 2 is turned on, the same processes as F-2 and F-3 above are executed in sequence. That is, a controlled vehicle speed storage step and a control start processing step are respectively executed.

F'-3 Next, execute the accelerator switch ON determination step. At this point, the accelerator switch 3 has not been turned on yet, so the determination result is "NO", and the accelerator flag presence determination step is then executed.

In the F'-4 accelerator flag presence determination step, it is determined that there is no accelerator flag and the determination result is "NO", and then the constant speed control processing step is executed.

F'-5 In the constant speed control processing step, the above F
Similarly to step 5, the control valve is driven at the duty ratio based on the control vehicle speed data and traveling speed signal d written in the storage section in the control vehicle speed storage step.

F'-6 Next, a cancel instruction signal presence determination step is executed. At this point, the judgment result is "NO", so the accelerator switch ON judgment step is executed again, and the accelerator switch is turned ON.
A closed loop consisting of a determination step, an accelerator flag presence determination step, a constant speed control processing step, and a cancel instruction signal presence determination step is sequentially executed.

F'-7 If accelerator switch 3 is turned on during this closed loop execution, the accelerator switch will turn on.
The determination result of the determination step is reversed to "YES", and the accelerator flag set step is executed this time.

F'-8 In this accelerator flag set step, the accelerator flag is set.

F'-9 Next, similarly to F-8 and F-9 above, the controlled vehicle speed storage step and the accelerator control processing step are sequentially executed.

F'-10 Next, the cancel instruction signal presence determination step is executed, and since the determination result is "NO", the accelerator switch ON determination step is executed again.

F'-11 The judgment result from the accelerator switch ON judgment step is still "YES", so
An accelerator flag setting step, a controlled vehicle speed storage step, and an accelerator control processing step are sequentially executed.

F'-12 When the accelerator switch 3 is turned on in this manner, a closed loop consisting of an accelerator switch ON determination step, an accelerator flag setting step, a controlled vehicle speed storage step, an accelerator control processing step, and a cancel instruction signal presence determination step is sequentially performed. The process is executed, and the control vehicle speed data is rewritten and the accelerator control process is performed.

F'-13 Then, when the traveling speed increases to the desired desired vehicle speed and the driver releases the ON operation of the accelerator switch 3, the determination result at the accelerator switch ON determination step returns to "NO", and then the accelerator flag is A presence determination step is executed.

F'-14 In this accelerator flag presence determination step, since the accelerator flag has already been set in the accelerator flag setting step described above, the determination result is "YES". Therefore, next, a step for determining vehicle speed>memory vehicle speed is executed.

F'-15 In this vehicle speed > memorized vehicle speed determination step, the vehicle speed corresponds to the traveling speed signal d inputted from the vehicle speed sensor 5, and the memorized vehicle speed is written in the memory section by the final controlled vehicle speed memorization step. Compatible with control vehicle speed data. At this point, the vehicle speed tends to increase due to the above-mentioned inertia of the engine 9, response delay of the throttle actuator 6, etc., so the determination result becomes "YES" and the fuel cut request signal ON output step is then executed.

F'-16 In this fuel cut request signal ON output step, a fuel cut request signal g of logic "1" is output to the fuel injection control device 10. When the fuel injection control device 10 receives this fuel cut request signal g of logic "1", it outputs a control signal h to the engine 9 so that engine braking occurs in the engine 9.

F'-17 Next, a constant speed control process step is executed, and the same process as F'-5 above is performed based on the desired vehicle speed after the speed increase.

F'-18 Next, a cancel instruction signal presence determination step is executed. If it is determined that there is no cancel instruction signal at this point, the determination result becomes "NO" and the accelerator switch ON determination step is then executed.

F'-19 The judgment result of this accelerator switch ON judgment step is still "NO",
Since the determination result in the next accelerator flag presence determination step is still ``YES'', the vehicle speed>memorized vehicle speed determination step is then executed.

F'-20 In this vehicle speed > memorized vehicle speed determination step, the vehicle speed still has an increasing tendency, so the determination result is ``YES'', and the fuel cut request signal ON output step and constant speed control processing step as described above are executed in sequence. Ru.

When the ON operation of the accelerator switch 3 is released in this way, the fuel cut request signal ON output step is executed, engine braking is generated in the engine 9, and the tendency of the vehicle speed to increase is suppressed.

F'-21 When the vehicle speed becomes less than the control vehicle speed, that is, the stored vehicle speed, the determination result in the vehicle speed>memorized vehicle speed determination step is reversed to "NO", and the accelerator flag clear step is executed this time.

F'-22 In this accelerator flag clear step, the accelerator flag set in the accelerator flag set step as described above is cleared.

F'-23 Next, execute the fuel cut request signal OFF output step. That is, the fuel cut request signal g is inverted from the logic "1" level to the logic "0" level, and the engine brake by the fuel injection control device 10 is released.

F'-24 Next, a constant speed control processing step is executed, and the same processing as F'-17 above is performed.

In this way, from the time when the ON operation of the accelerator switch 3 is released until the vehicle speed becomes equal to or less than the memorized vehicle speed, the fuel cut request signal g at the logical "1" level is output and engine braking continues to be generated, thereby preventing the vehicle speed from increasing. The vehicle speed is sufficiently suppressed and stabilized at the controlled vehicle speed in a relatively short time.

F'-25 Then, when the driver operates the brake pedal while driving at a constant speed, the determination result at the cancel instruction signal presence determination step is reversed to "YES" as in F-14 above, and this time, the cancellation processing step is performed. is executed. It goes without saying that the cancel instruction signal includes various instruction signals caused by neutral operation, parking brake operation, and clutch operation (in the case of a manual vehicle).

F'-26 Next, the set switch ON determination step is executed again, and the series of processes as described above in F'-1 to F'-25 are executed.

As explained above, the present invention includes a storage unit that stores controlled vehicle speed data based on a traveling speed signal, and performs accelerator control processing and rewrites the stored vehicle speed data during an accelerator instruction signal ON period while driving at a constant speed.
and an arithmetic processing section that performs constant speed control processing based on the stored vehicle speed data at the end of rewriting when the accelerator instruction signal is turned off, the arithmetic processing section is controlled by the accelerator instruction signal. a storage unit that determines the magnitude of the controlled vehicle speed and the traveling speed based on the stored vehicle speed data at the end of rewriting and the traveling speed signal when the vehicle is turned off, and stores the controlled vehicle speed data by operating the set switch; an accelerator switch that instructs acceleration processing of the vehicle by an accelerator instruction signal while driving at a constant speed based on the stored control vehicle speed data; When the control vehicle speed data stored in is rewritten and the accelerator instruction signal is no longer output, the rewriting is completed and the constant speed control is performed using the control vehicle speed data at the end of this rewriting as the constant speed target vehicle speed. In a vehicle speed control device comprising an arithmetic processing unit that performs processing, at least after the operation of the accelerator switch is released and the accelerator instruction signal is no longer output, the constant speed target vehicle speed and the vehicle speed sensor are determined. A speed comparison means determines the magnitude of the current vehicle speed, which is an input actual vehicle running speed, and a speed comparison means determines whether the current vehicle speed is greater than or equal to the current vehicle speed when the accelerator instruction signal is no longer output. The fuel cut instructing means instructs the fuel injection control device to cut the fuel until it is determined that the vehicle speed is lower than the target vehicle speed.

Therefore, according to the present invention, when the fuel injection control device is instructed to cut fuel, it controls the engine to generate engine brake, thereby suppressing the tendency of the vehicle speed to increase during the transient period as described at the beginning of the specification. This can be suppressed sufficiently and the vehicle speed can be returned to the controlled speed in an extremely short period of time.

Therefore, it becomes extremely easy to determine the timing of the accelerator switch-off operation, and it is also possible to maintain safe driving.

Further, in the embodiments described above, the fuel cut request signal of logic "1" level is output while the vehicle speed exceeds the stored vehicle speed, but the present invention is not limited to this. This also includes a case where a fuel cut request signal of logic "1" level is output while the vehicle speed is higher than the stored vehicle speed, and it goes without saying that the same effect can be achieved in this case as well.

Although the throttle actuator described above has been explained as being of the vacuum type, it goes without saying that the present invention can be applied to a motor type as well, since the same response delay occurs, and the same excellent effects can be achieved.

[Brief explanation of drawings]

FIG. 1 is an example of the configuration of the main parts of a speed control system to which a conventional vehicle speed control device is applied, FIG. 2 is a flowchart for explaining its main processing operations, and FIG. 3 is for explaining the present invention. FIG. 4 shows a main part configuration of a speed control system to which a vehicle speed control device according to an embodiment of the present invention is applied, and FIG. 5 shows a flow chart for explaining its main processing operations. 1'...Speed control device, a...Set instruction signal,
b...Accelerator instruction signal, d...Traveling speed signal,
g...Fuel cut request signal.

Claims (1)

[Scope of Claims] 1. A storage unit that stores controlled vehicle speed data based on the operation of a set switch; and an accelerator that instructs acceleration processing of the vehicle using an accelerator instruction signal while driving at a constant speed based on the stored controlled vehicle speed data. The switch performs acceleration processing of the vehicle and rewrites the control vehicle speed data stored in the storage unit while the accelerator instruction signal is being output, and when the accelerator instruction signal is no longer output, the rewriting is performed. In the vehicle speed control device, the vehicle speed control device includes an arithmetic processing unit that performs a constant speed control process using the controlled vehicle speed data at the end of this rewriting as a constant speed target vehicle speed, when at least the operation of the accelerator switch is released. After the accelerator instruction signal is no longer output, speed comparison means determines the magnitude of the constant speed running target vehicle speed and the current vehicle speed that is the actual vehicle running speed input from the vehicle speed sensor; fuel cut instruction means for instructing the fuel injection control device to cut fuel from the time when the signal is no longer output until the time when the current vehicle speed is determined by the speed comparison means to be smaller than the constant speed running target vehicle speed; A vehicle speed control device comprising: