JP2563299Y2 - Automatic vehicle speed control - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic vehicle speed control device for automatically running a vehicle at a constant vehicle speed set by an occupant.

[0002]

2. Description of the Related Art As an automatic vehicle speed control device, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-216835, a control unit constituted by a microcomputer is set by a command switch operated by an occupant. A speed difference between the set vehicle speed and the detected vehicle speed detected by the vehicle speed sensor is calculated, and the speed difference is compared with a preset reference value to select constant speed traveling control or acceleration traveling control. Based on the traveling control, the vent valve on the fuel supply mechanism side,
An electromagnetic actuator such as a safety valve or a vacuum valve is driven, a diaphragm is driven by the electromagnetic actuator, and a throttle valve is driven by the diaphragm to drive the vehicle at a set vehicle speed.

[0003]

In the above-mentioned prior art, the speed difference between the set vehicle speed and the detected vehicle speed is uniquely determined on the fuel supply mechanism side based on a control characteristic preset in the control unit. The drive is controlled. However, during acceleration running control, when the speed difference between the set vehicle speed and the detected vehicle speed is large, when the vehicle is running uphill, the pulling amount of the throttle valve increases, and the shift position of the transmission is changed to a shift position with a large gear ratio ( Downshift). Due to this, when the detected vehicle speed approaches the set vehicle speed, the speed difference between the set vehicle speed and the detected vehicle speed reaches the reference value, and when shifting from acceleration traveling control to constant speed traveling control, due to a response delay of an electromagnetic actuator, etc., There is a disadvantage that the return of the throttle valve is delayed and an overshoot phenomenon occurs in which the detected vehicle speed (actual vehicle speed) exceeds the set vehicle speed.

Therefore, in the present invention, during acceleration running control, when the transmission shifts down, the reference value for shifting from acceleration running control to constant speed running control is set to a small value that is separated from the set vehicle speed. Accordingly, it is an object to prevent the occurrence of the overshoot phenomenon.

[0005]

According to the present invention, as shown in FIG. 1, a speed difference between a vehicle speed set by a vehicle speed setting means a and a detected vehicle speed detected by a vehicle speed detecting means b is set in advance. A comparison is made between the reference value and the constant speed traveling control or the acceleration traveling control. Based on the selected traveling control, the electromagnetic actuator c on the fuel supply mechanism side is driven to drive the vehicle at the set vehicle speed. In the automatic vehicle speed control device provided with the traveling control means d, a transmission position detecting means e for detecting a transmission shift position of the transmission, and a transmission position detected by the transmission position detecting means e at the time of the acceleration traveling control. Determining means f for determining whether the shift position has been changed to a gear position with a large gear ratio; and the traveling control means based on a determination result from the determining means f that the shift position of the transmission has been changed to a gear position with a large gear ratio. And a, a correction unit g to be outputted to the traveling control unit d the corrected output of the reference value is changed to a small value away from the set speed in.

[0006]

When the occupant operates the vehicle speed setting means a to set the desired vehicle speed as the set vehicle speed, the traveling control means d determines the set vehicle speed from the set vehicle speed means a and the detected vehicle speed detected by the vehicle speed detection means b. The speed difference between the set vehicle speed and the detected vehicle speed is compared with a reference value to select either constant speed traveling control or acceleration traveling control, and the electromagnetic actuator c is driven based on the selected traveling control. The vehicle is driven to reach the set vehicle speed. When the traveling of the vehicle is under the acceleration traveling control, the determining means f takes in the detected shift position from the shift position detecting means e and determines whether the shift position of the transmission has been changed to a shift position with a large gear ratio. When the determining means f determines that the gear position of the transmission has been changed to a gear position with a large gear ratio, the correcting means g changes the reference value in the traveling control means d to a small value that departs from the set vehicle speed. Is output to the travel control means d. As a result, the timing of shifting from the acceleration traveling control to the constant speed traveling control is advanced.

[0007]

FIG. 2 shows an automatic vehicle speed control device as one embodiment. In FIG. 2, a vehicle speed sensor 1 as a vehicle speed detecting means is provided on a drive shaft side of a transmission (not shown), detects an actual vehicle speed of the vehicle, and outputs an electric signal corresponding to the detected vehicle speed to a microcomputer in the control unit 2. And outputs to the control unit 3 including the traveling control means d, the shift position detecting means e, the determining means f, and the correcting means g shown in FIG. 1 via the input interface 4 in the control unit 2.

The vehicle speed setting means 5 sets the vehicle speed desired by the occupant as the set vehicle speed through the input interface 4 by the operation of the occupant. The set switch 6 and the resume switch 7 It has become. The set switch 6 is mainly used to set a set vehicle speed or reduce the set vehicle speed. For example, when the occupant depresses an accelerator pedal (not shown) and the vehicle reaches a desired vehicle speed, the set switch 6 is pressed and released (on-off operation), and the detected vehicle speed from the vehicle speed sensor 1 at that time is transmitted to the control unit 3. It is set as the set vehicle speed. When the occupant keeps pushing the set switch 6 (continuous ON operation), the control unit 3 controls the electromagnetic actuator 9 on the fuel supply mechanism side to the fuel decreasing side via the output interface 8 to drive the vehicle by the engine brake. When the vehicle speed has been reduced to the desired vehicle speed, the set switch 6
Is released (off operation), the detected vehicle speed from the vehicle speed sensor 1 at that time is updated to the control unit 3 as a set vehicle speed lower than the set vehicle speed already set in the control unit 3 (newly set). Is done. The resume switch 7 is mainly used to increase the set vehicle speed. For example, if the resume switch 7 is continuously pressed (ON continuous operation), the set vehicle speed increases. , Is updated by the control unit 3.

The release detecting means 10 detects the braking operation or the power cutoff operation of the vehicle and outputs it to the control unit 3 via the input interface 4 to release the automatic control of the vehicle speed of the control unit 3. A stop lamp switch 11 for turning on / off an external stop lamp, a brake switch 12 for detecting a braking operation (depressing) of a brake pedal (not shown), and a power cutoff operation of a clutch (clutch with a transmission in an automatic vehicle) not shown. Is detected by the clutch switch 13.

An engine speed sensor 14 as an engine speed detecting means detects an actual engine speed and outputs an electric signal corresponding to the detected engine speed to the control unit 3 via the input interface 4. Then, the shift position detecting means e (see FIG. 1) in the control unit 3 sets the detected engine speed from the engine speed sensor 14 and the detected vehicle speed from the vehicle speed sensor 1 in the control unit 3 in advance. The shift position of the transmission (not shown) is detected by checking the shift position map shown in FIG. The shift position map shown in FIG. 3 is knowledge that defines the relationship between the vehicle speed, the engine speed, and the shift position. The horizontal axis shows the vehicle speed, the vertical axis shows the engine speed, and the first quadrant. A plurality of shift positions and a plurality of shift position determination lines are shown. In this embodiment, since the transmission is assumed to be an automatic transmission, “1 shift position (first range)” and “2 shift position (second range)” are included in the first quadrant of the shift position map. 1-2 to classify
The shift position determination line L ₁ , the 2-3 shift position determination line L ₂ that separates “2 shift position” and “3 shift position (third range)”, “3 shift position” and “OD shift position (overdrive range) 3-OD shift position determination line L ₃
Have each. Then, according to this shift map, the shift position detecting means e compares the detected vehicle speed with the detected engine speed, and the "1 shift position" and "2 shift position" where the intersection between the detected vehicle speed and the detected engine speed is located. And outputs a detected shift position signal corresponding to any of the "position", "3 shift positions", and "OD shift position".

The constant voltage circuit 1 in the control unit 2
Reference numeral 5 denotes a state in which the main switch 17 for automatic vehicle speed control is turned on in a state where the ignition switch 16 is turned on.
8 supplies power to the control unit 3 and the input interface 4.

A reset circuit 19 in the control unit 2 sets the control unit 3 to an initial state when the control unit 3 is started.

The safety relay 20 in the control unit 2 is turned on via the output interface 8 when the automatic vehicle speed control device is normally operating, and the power supply line 21 on the main switch 17 side of the electromagnetic actuator 9 is turned on.
Is closed through an output interface 8 when an abnormality occurs, and the power supply line 2 of the electromagnetic actuator 9 is closed.
1 is being developed. The above-mentioned abnormal state means that the control unit 3, the input interface 4, the output interface 8, the constant voltage circuit 15, the reset circuit 19, and the like are short-circuited or broken, and the vehicle speed sensor 1, the vehicle speed setting means 5, the release detecting means 10, etc. This is a state in which the controller continues to rise to the fuel increasing side from the control unit due to a short circuit in the wiring.

The electromagnetic actuator 9 includes a negative pressure pump motor 22, an air valve 23, and a release valve 24. When the main switch 17 is turned off and the automatic vehicle speed control is not operated, the negative pressure pump motor 22 is stopped. Then, the air valve 23 and the release valve 24 are opened, and the operation of the unillustrated vacuum valve that drives the unillustrated control valve of the fuel supply mechanism is stopped. When the main switch 17 is turned on and the vehicle speed automatic control is activated, the electromagnetic actuator 9 closes the release valve 24,
Opening / closing of air valve 23 and motor 22 for negative pressure pump
By driving / stopping the vacuum valve, a negative pressure or atmosphere is introduced into the inside of the vacuum valve to operate the vacuum valve. It should be noted that the control valve is, of course, activated by the operation of the accelerator pedal by the occupant regardless of whether the automatic vehicle speed control is inactive or inactive.

The output interface 8 is connected to an indicator 25 configured as a lamp device or a sound generating device for notifying the driver of the automatic vehicle speed control operation of the control unit 3.

The operation of this embodiment will be described with reference to the flowchart shown in FIG. The occupant turns on the ignition switch 16, turns on the main switch 17, activates the control unit 2, and the control unit 3
For each scanning period of the microcomputer, a pulse signal generated in proportion to the actual vehicle speed from the vehicle speed sensor 1 is sampled as a detected vehicle speed, and a pulse signal generated in proportion to the actual engine speed from the engine speed sensor 14 is detected. Sampling is performed as the engine speed. When the occupant operates the vehicle speed setting means 5, the vehicle speed automatic control starts, and the control unit 3 sets the sampled detected vehicle speed at that time as the set vehicle speed (sampling hold).
I do. Then, the sampled detected vehicle speed and detected engine speed are checked against a shift position map to calculate a shift position of the transmission, and the calculated shift position is stored (set) as an initial shift position ( Step 102, 1
03). Subsequently, the reference value K for determining whether to perform the constant speed traveling control or the acceleration traveling control (resume return control) is represented by K = a.
(Step 104). Next, a speed difference between the sampled and held set vehicle speed and the detected vehicle speed sampled in the next scanning period is calculated, and it is determined whether or not the speed difference is equal to or more than the reference value K (steps 105 and 10).
6). If the speed difference is equal to or less than the reference value K (NO in step 106), the process proceeds to step 107 to perform constant speed traveling control because the speed difference between the set vehicle speed and the detected vehicle speed is small. Conversely, when the speed difference is larger than the reference value K (YES in step 106), the process proceeds to step 108 to perform acceleration traveling control because the speed difference between the set vehicle speed and the detected vehicle speed is large. When the acceleration traveling control starts, the detected vehicle speed and the detected engine speed sampled in the next scanning period are compared with a shift position map to calculate a shift position of the transmission (step 109). Then, the shift position calculated in step 109 and step 10
The gear position set in step 3 is compared with the gear position to determine whether the gear position of the transmission has been changed to a gear position with a large gear ratio (shift down) (step 110). And
If the transmission is not downshifted (step 11
0 is NO), it means that the vehicle is not traveling uphill, the engine is not overloaded, the amount of throttle valve pulling by the electromagnetic actuator 9 is not so large, and the engine speed is not so high. So it means
It returns to step 105. Conversely, if the transmission is downshifted (YES in step 110), the engine is overloaded due to the vehicle traveling uphill, etc., and the amount of throttle valve pulling by the electromagnetic actuator 9 increases, and the engine speed increases. Is higher, the routine proceeds to step 111, where the reference value K is set to K = b. The value b is a small value that is farther from the set vehicle speed than the value a in step 104. After setting the reference value K = b, the process returns to step 105.

In short, according to this embodiment, in the acceleration traveling control, when the transmission shifts down, the reference value K for shifting from the acceleration traveling control to the constant speed traveling control is changed from the value a to the value b.
, The timing of shifting from the acceleration traveling control to the constant speed traveling control becomes earlier, the return of the throttle valve by the electromagnetic actuator 9 becomes earlier, and the actual vehicle speed (detected vehicle speed) exceeds the set vehicle speed. The phenomenon can be prevented from occurring. This will be described with reference to the timing chart shown in FIG.
First, it is assumed that the shift position of the transmission is in the OD shift position, acceleration running control at time t ₁ starts the transmission at time t ₂ is shifted down to the "third speed gear position". Then, the amount of pulling of the throttle valve by the electromagnetic actuator 9 increases, the engine speed increases, and the detected vehicle speed increases to the set vehicle speed side. Then, when the speed difference between the set vehicle speed and the detected vehicle speed becomes the reference value K = b, the process shifts from the acceleration traveling control to the constant speed traveling control. Thus, as indicated by a solid line, and decreases the engine speed, without detecting the rotational speed exceeds the set speed, after the engine speed has stabilized, the shift position is "third gear shift position of the transmission at time t ₃ ”To the“ OD shift position ”(shift up). In contrast, as shown by dotted lines, in the comparative example corresponding to the conventional example, even if the transmission is shifted down at time t _2, the difference in speed is the reference value K = a between the set vehicle speed and the detected vehicle speed When it comes to
Since the vehicle shifts from the acceleration running control to the constant speed running control, the engine speed continues to increase even if the detected vehicle speed approaches the set vehicle speed due to the response delay of the electromagnetic actuator 9, and an overshoot phenomenon in which the detected vehicle speed exceeds the set vehicle speed occurs. Occurs.

In the above embodiment, the shift position of the transmission is calculated by comparing the detected vehicle speed and the detected engine speed with the shift position map. However, the shift position of the transmission is used as the shift position detecting means. The same operation and effect can be obtained by providing a sensor for detecting the input signal, and taking the output from this sensor into the control unit 3 via the input interface 4.

[0019]

As described above, according to the present invention, the vehicle speed desired by the occupant is set as the set vehicle speed, and when the acceleration traveling control starts due to the speed difference between the set vehicle speed and the detected vehicle speed, the transmission shifts down. If the transmission shifts down, the selection reference value of the acceleration traveling control and the constant speed traveling control is corrected to a small value apart from the set vehicle speed.
The timing of shifting from the acceleration traveling control to the constant speed traveling control is advanced, the return of the throttle valve by the electromagnetic actuator 9 is advanced, and it is possible to prevent an overshoot phenomenon in which the actual vehicle speed exceeds the set vehicle speed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing the present invention.

FIG. 2 is a configuration diagram showing one embodiment.

FIG. 3 is a shift position map according to one embodiment.

FIG. 4 is a flowchart of an embodiment.

FIG. 5 is a timing chart illustrating the operation of one embodiment.

[Explanation of symbols]

 a ... vehicle speed setting means b ... vehicle speed detecting means c ... electromagnetic actuator d ... traveling control means e ... shift position detecting means f ... determining means g ... correcting means 1 ... vehicle speed sensor 3 ... control unit 5 ... vehicle speed setting means 9 ... electromagnetic actuator 14. Engine speed sensor

Claims (1)

(57) [Scope of request for utility model registration] 1. A constant speed driving control or an acceleration driving control is selected by comparing a speed difference between a set vehicle speed set by a vehicle speed setting means and a detected vehicle speed detected by a vehicle speed detecting means with a preset reference value. An automatic vehicle speed control device including a traveling control means for driving the vehicle at a set vehicle speed by driving an electromagnetic actuator on the fuel supply mechanism side based on the selected traveling control. Shift position detecting means for detecting a position; determining means for determining whether the shift position of the transmission has been changed to a shift position with a large gear ratio based on the detected shift position from the shift position detecting means during the acceleration traveling control. Based on the result of the determination that the shift position of the transmission has been changed to the shift position with a large gear ratio from the determination unit, the reference value in the travel control unit is changed to a small value that departs from the set vehicle speed. And a correcting means for outputting a corrected output to the traveling control means.