JPS63265739A - Control device for traveling of vehicle - Google Patents

Abstract

PURPOSE:To automatically select a constant speed traveling controllable area even on an ascent in addition to constant speed traveling on a flat road traveling by detecting the gradient of a traveling road by means of an inclination angle sensor. CONSTITUTION:Signals from a vehicle speed sensor 23 and a theta sensor 24 are inputted into a microcomputer control unit 31. When an inputted inclination angle is judged to be above a previously set first reference value, an ascent is detected. And, by checking whether an ascent was detected in an interruption processing one cycle before and when it was not detected, judgment is formed to be immediately after entering an ascent. And, when the inclination angle of a traveling road is above the first reference value and below a second reference value, the vehicle speed V at the time of operating a resume switch is stored in a RAM 39 as the set vehicle speed Vc of constant speed traveling on an ascent. Further, when the inclination angle becomes above the second reference value, a brake pressure is comparatively controlled with respect to the inclination angle, to deceleratingly control the target vehicle speed for constant speed traveling.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention enables appropriate switching control between constant speed running control, deceleration running control, and manual running in response to road conditions. The present invention also relates to a vehicle travel control device that can control constant speed travel on flat roads and slopes, and changes the set vehicle speed when the slope angle exceeds a predetermined value.

[Conventional technology]

Conventionally, from the viewpoint of safe driving, constant speed driving control devices for vehicles have generally been used only when driving on flat roads.

FIG. 7 is a system block diagram of a conventional constant speed cruise control device. In this FIG. 7, 23 is a vehicle speed sensor for detecting vehicle speed, 25 is a brake switch activated by brake operation, and 27 is a system block diagram of a conventional constant speed cruise control device. A center switch 29 outputs a set signal when operated by the driver, and a resume switch 29 outputs a resume signal (No. 3) when operated by the driver. connected to.

In addition, the microcomputer control unit 31 also controls the throttle valve (
Throttle opening control device 3 that adjusts the opening (not shown)
3 to output an opening control signal to control the vehicle speed.

Note that the microcomputer control unit 31 is CPIJ35, RO
The configuration includes an M37, a RAM 39, and an input/output port 41.

Next, the operation of the conventional device will be described. First, the vehicle speed ■ is input from the vehicle speed sensor 23 to the microcomputer control unit 31 . When the driver turns on the Sera 1 and the switch 27 in this state, the vehicle speed at that time is stored in the RAM 39 as the set vehicle speed Vc.
Thereafter, the vehicle speed is made to follow this set vehicle speed, and the throttle opening degree control device 33 is controlled so that the throttle opening degree is proportional to the vehicle speed deviation.

By the way, the conventional device does not have a special sensor to distinguish between a flat road and an uphill road, so if the driver visually determines that it is possible to drive at a constant speed on a substantially flat road, the set switch is activated. 27 was turned on and the vehicle was traveling at a constant speed using the vehicle speed at that time as the set vehicle speed, and generally, constant speed traveling control is not performed on the uphill road.

Further, when the vehicle enters a hill on a flat road with constant speed driving control set, constant speed driving control is canceled only by the driver's brake operation.

Furthermore, if the resume switch 29 is erroneously operated on the uphill road, the constant speed cruise control will be set, and thereafter the constant speed cruise control cannot be canceled unless the brake is operated as in the case described above.

[Problem that the invention seeks to solve]

That is, in the conventional example, there is no other way to release the fail-safe mechanism other than by operating the brake switch by operating the brake.

This invention was made to solve this problem, and it is possible to apply constant speed driving control to general slopes, expand the utilization efficiency of the constant speed driving control device, and improve safety. The purpose is to obtain equipment.

[Means for solving problems]

The vehicle running control device according to the present invention includes a tilt angle sensor that detects the tilt angle of a slope, and a detection output of the tilt angle sensor to discriminate between a flat road and a slope. A vehicle speed control means is provided that performs constant speed driving control on slopes in the same manner as on flat roads, changes the set vehicle speed on uphill slopes with a slope angle of more than a predetermined angle, and performs brake control on downhill slopes when the vehicle speed deviation increases. It is something.

[For production]

In this invention, the inclination angle of the traveling road is detected by the inclination angle sensor, and when the detected value exceeds the first reference level, it is determined that the road is a slope, the driving mode is reset to the initial state, and the detected output level is is higher than the first reference level and lower than the second reference level, constant speed driving control is enabled at a set vehicle speed with the vehicle speed at the time the resume switch is operated as the upper limit, and the output level of the inclination angle sensor is set to the second reference level. If the standard level is exceeded, the target vehicle speed for constant speed driving is controlled according to the degree of slope of the road, and constant speed driving control is continued even if the road starts to slope downward. When the vehicle speed deviation exceeds a predetermined reference value, the brake control decelerates the vehicle to a safe driving speed and then returns to manual mode.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the vehicle travel control device of the present invention will be described below with reference to the drawings. FIG. 1 is a system block diagram of this embodiment. In FIG. 1, parts that are the same as those in FIG. 7 are given the same reference numerals, and parts that are different from those in FIG. 7 will be mainly described.

The difference between FIG. 1 and FIG. 7 is that an inclination angle sensor 24 (hereinafter referred to as θ sensor) for detecting the inclination angle of the traveling road as an uphill road detection means is connected to the input port of the microcomputer control unit 31. Additionally, a brake control device 34 is newly connected to the output boat. Other parts are the same as those shown in FIG.

Next, the control action of this invention will be described. First, a vehicle speed signal from the vehicle speed sensor 23 and a tilt angle signal from the θ sensor 24 are input to the microcomputer control unit 31.

Next, it is determined that the input inclination angle is greater than or equal to a first preset reference value to detect a climbing road, and it is also checked whether a climbing road was detected in the interrupt process one cycle before, and whether or not the climbing road is detected is determined. In this case, it is determined that the driver has just entered the pitching route.

If the slope angle of the traveling road exceeds the first reference value and is less than the second reference value, the vehicle speed at the time the resume switch is operated is
is stored in the RAM 39 as iVc, a vehicle set to run at a constant speed on a boarding road, which will be described later.

Next, if an uphill road is currently being detected, while traveling on the uphill road,
It is determined whether the resume switch 29 has ever been turned on, and if it has been turned on, the mode is set to constant speed driving mode, and if it remains off, the mode is set to manual mode.

Also, while driving in constant speed driving mode, the inclination angle of the driving road may be
When the reference value of is set to a circle, the target speed for constant-speed driving can be modified and controlled in accordance with the angle of inclination (for example, the target vehicle speed is decreased as the angle of inclination increases).

Furthermore, it is determined whether or not the set switch 27 has ever been turned on while driving on a flat road, and if it has been turned on, it is set to constant speed driving mode, and if it remains off, it is set to manual mode. Return to

Next, even when a downhill slope is reached during uphill driving, the constant speed driving mode is continued, but if the vehicle speed deviation increases and its value exceeds a predetermined reference value, the constant speed driving mode ．． is released and set to deceleration mode, the brake control device is activated to decelerate to a predetermined safe speed, and at this point the vehicle speed printing section is released and the vehicle is returned to manual mode.

In addition, in the case of a constant speed driving mode on a boarded road, in order to drive at a constant speed at the set vehicle speed Vc stored in the RAM 39, an opening control signal corresponding to the difference between the vehicle speed V and the set vehicle speed Vc is transmitted at a constant speed on a flat road. In the driving mode, the vehicle speed at the time when the set switch 27 is activated is set as the set vehicle speed Vc, and the opening control signal is output to the throttle opening control device 33 to control the vehicle speed in the same way as in the above case.

FIG. 2 is a system block diagram of a second embodiment of the present invention. The difference from the first embodiment is that the throttle sensor 28 for detecting the throttle level is connected to the microcomputer control unit 3.
The point is that a fuel cut device 36 for cutting off the fuel supply to the engine is added to the input port of No. 1 and to the output boat.

Regarding the operation of the second embodiment, the difference from the first embodiment is that in the i-speed control mode described in 7 above, the speed does not decelerate to the safe running speed even after a predetermined period of time has elapsed after the start of brake control, and the throttle When the opening degree is less than a predetermined opening degree, the fuel cut device 36 is operated to reliably reduce the vehicle speed to a safe running speed, thereby improving the safety of the vehicle.

Figure 3 shows the first part of the brake control device in deceleration traveling control.
1 shows a block diagram of an embodiment of the invention. In this Fig. 3, 101 is a wheel, 1o2 is a brake cylinder,
103 is a brake pedal, 104 is a mask cylinder, 1
04a is the high pressure boat of the mask cylinder 104, 104b
is the low pressure boat of the mask cylinder 104.

The high pressure boat 104a has a hydraulic pipe line 105a and a two-way solenoid valve 1.
36, is connected to the brake cylinder 102 via a hydraulic pipe line 105c and a fixed orifice 124.

A pressure sensor 137 is provided in the hydraulic conduit 105c, and the surge tank 134 is communicated with the pressure sensor 137.

Furthermore, the low pressure boat 104b of the mask cylinder 104 communicates with the reservoir tank 131 via a hydraulic conduit 105d.

A hydraulic tank 130 communicates with this reservoir tank 131 via a hydraulic pipe 1051, and an output boat of the hydraulic pump 130 communicates with the reservoir tank 131 via a two-way solenoid valve 135. 05b and a two-way solenoid valve 132, it is connected to a hydraulic conduit 105C.

The hydraulic conduit 105c is connected to the cylinder left chamber 120 of the cylinder device 106 via a three-way solenoid valve 118. The piston 107 of the cylinder device 106 has a spring 108
The cylinder is constantly pressed in the direction of the cylinder left chamber 120, thereby minimizing the volume of the cylinder left chamber 120.

The cylinder right chamber 121 has hydraulic pipes 105g and 105e.
.

It is connected to the cylinder left chamber 120 via a solenoid type variable orifice 122. 122a is a solenoid air of the solenoid type variable orifice 122.

The connection point of the hydraulic pipes 105g and 105e is the solenoid type variable orifice 123 and the hydraulic pipe 105f.

It is connected to the cylinder left chamber 120 via 105h, and also communicates with the reservoir tank 131. 12
3a is a solenoid coil.

Next, the operation of this brake control device will be explained. In the normal braking state, the two-way solenoid valve 36 is in the on state.
Therefore, the mask cylinder oil pressure corresponding to the amount of brake depression is applied to the oil pressure pipe 105a.

105ce&! ! The brake fluid is then supplied to the brake cylinder 120 for normal braking operation.

In addition, in the brake off state, the mask cylinder 104
The high pressure boat 104a is in communication with the low pressure boat 104b,
It communicates with the reservoir tank 131 via the hydraulic pipe $105d, and the brake operating pressure is released.

Next, in the deceleration running state, the two-way solenoid valve 1361. T-off, 2-way? The ff magnetic valve 132 is turned on, and the I'113 pressure of the hydraulic pump 130 is applied to the hydraulic pipes 105b and 10.
It comes to act on the brake cylinder 102 via 5c.

Pressure switch 137: Operates when the pump oil pressure reaches a predetermined pressure, turns off the two-way solenoid valve 132, and seals pump hydraulic oil into the hydraulic conduit 105C.

When the 30,000 thunder magnet valve 118 is turned on in this state, a part of the hydraulic oil sealed in the hydraulic line 105C is released into the cylinder device 1.
In order to flow into the cylinder left chamber 120 of No. 06, the pressure should be reduced corresponding to the internal volume of this cylinder left chamber 120.

Normally, the cylinder left chamber 120 is positioned at an initial position where the volume of the left chamber 120 is minimized by the action of the spring 108.

On the other hand, solenoid-type variable orifices 122 and 123 are inserted in series between the cylinder left chamber 120 and the reservoir tank 131, and both solenoid-type variable orifices 12
The connection point No. 2,123 is connected to the cylinder left chamber 121 of the cylinder device 106 via a hydraulic conduit 105g.

Therefore, the hydraulic pressure determined by the diameters of the two solenoid-type variable orifices 122 and 123 acts on the cylinder right chamber 12. It stops at the position where it balances with the resultant force of the connection point oil pressure at ゜123.

By the way, in order to increase the brake cylinder working pressure, it is sufficient to reduce the volume of the cylinder left chamber 120.
Therefore, both solenoid type variable orifices 122, 12
All you have to do is increase the oil pressure at connection point 3.

For this purpose, the diameter of the solenoid-type variable orifice 123 may be narrowed relative to the solenoid-type variable orifice 122, or the diameter of the solenoid-type variable orifice 1220 may be made looser relative to the solenoid-type variable orifice 123.

Such control is performed by the solenoid coils 122a of these solenoid type variable orifices 122, 123.

This can be easily done by controlling the excitation current of 123a.

Therefore, if the coil current is controlled by increasing the current in the solenoid coil 122a or decreasing the current in the solenoid coil 123a in accordance with the increase in the inclination angle θ, or by the inverse combination of the above, the inclination angle It is also possible to proportionally control the brake oil pressure P in accordance with θ, and the brake control characteristics in this case are shown in FIG.

In addition, the surge tank 134 and the fixed orifice 124 are
This is to absorb the surge pressure that occurs when the solenoid valves 136, 132, etc. are turned on to obtain a smooth start-up.
The two-way solenoid valve 133 is a υt pressure valve for rapidly removing the residual pressure in the hydraulic line when the brake control is stopped.

Furthermore, the two-way solenoid valve 135 is a short-circuit valve that connects the output port of the hydraulic pump 130 to the reservoir when energized and makes the output pressure zero.

・Figure 4 shows a block diagram of the second embodiment of the brake control device for deceleration traveling control.
The difference from the embodiment is that the solenoid type variable orifice 12
Since the fixed orifice 122 is used in the second embodiment, the other components are the same as those in the second embodiment, so detailed explanations will be omitted.

Next, the operation of this brake control vJJ device will be explained. Since the operation in this case is almost the same as that in the first embodiment, only the main points will be described.

Now I'm building a pump on hydraulic line 105C! In order to increase the brake pressure in a state where IOJ oil is sealed, it is possible to increase the brake pressure by narrowing the diameter of the solenoid type variable orifice 123 relative to the fixed orifice 122.

Further, the brake pressure can be reduced by loosening the diameter of the solenoid type variable orifice 123 with respect to the fixed orifice 122.

Therefore, by controlling the current of the solenoid coil 123a of the solenoid-type variable orifice 123 with respect to the inclination angle θ, the brake hydraulic pressure P is
It is also possible to perform proportional control as shown in the figure.

Figure 5 shows the third part of the brake control device in deceleration traveling control.
This figure shows a block diagram of the first embodiment, and the difference from the first embodiment shown in FIG.
Since the fixed orifice 123 is used instead of the fixed orifice 123, the other components are the same as those in the first embodiment, so detailed explanations will be omitted.

Next, the operation of this brake control device will be described. Since the operation in this case is almost the same as that in the first embodiment, only the main points will be described.

Now, in order to increase the brake pressure in a state where pump hydraulic oil is sealed in the hydraulic conduit 105C, it is possible to increase the brake pressure by loosening the diameter of the variable orifice 122 with respect to the fixed orifice 123.

In addition, in order to reduce the brake pressure, a solenoid type variable orifice 1220 is connected to the fixed orifice 123.
This is possible depending on the caliber and the pattern.

Therefore, by controlling the deflection of the solenoid-type variable orifice 122 and the noid coil current with respect to the inclination angle θ, it is also possible to proportionally control the brake oil pressure P with respect to the inclination angle θ, as shown in FIG.

As described above, the control action of the device of the present invention can be summarized as follows.

fl) When driving on a flat road, perform constant speed driving control using the vehicle speed at the time of switch operation as the target vehicle speed.

(2) When the resume switch is turned on while traveling uphill If the inclination angle is equal to or greater than the second reference value, constant speed traveling control is performed in which the vehicle speed at the time the resume switch is operated is set as the target vehicle speed.

(3) When the resume switch is turned on while driving uphill, if the tilt angle exceeds the second reference value, the target vehicle speed is corrected, and if the vehicle speed width difference exceeds a predetermined value on a downhill slope, the brake control device is activated. Throttle opening is below the specified level (
) 13 Under certain conditions, the fuel supply to the engine is cut off by fuel cut control, and the engine speed is reduced to a predetermined safe speed.
After speeding up, driving control was canceled and the vehicle did not return to manual mode.

〔Effect of the invention〕

As explained above, in addition to the conventional constant speed driving on a flat road, this invention automatically selects a constant speed driving controllable range even on an uphill road, and detects the slope of the driving path using an inclination angle sensor. When this value exceeds a certain level λ, the target vehicle speed is set to 0y, and when the vehicle speed deviation exceeds a predetermined value on a downhill slope, the vehicle enters deceleration mode using brake control, and after being decelerated to a safe speed, it enters manual mode. Since the vehicle is returned to its original state, the driving side @ device, which has higher safety than conventional devices, is provided with live commentary.

Further, in deceleration control, the brake pressure can be controlled proportionally in accordance with the inclination angle, making it possible to perform brake control with improved controllability.

[Brief explanation of drawings]

FIG. 1 is a system block diagram of one embodiment of the vehicle travel control device of the present invention, FIG. 2 is a system block diagram of another embodiment of the vehicle travel control device of the present invention, and FIGS. 3 to 5 FIG. 6 is a diagram showing the brake control characteristics of the above brake control device, and FIG. 7 (
1 is a system block diagram of a conventional constant speed cruise control device. 239. Vehicle speed sensor, 24... Tilt angle sensor, 25 Brake switch, 27... Set switch, 28- Throttle sensor, 29... Resume switch, 31...
...Microcomputer control unit, 33.-Throttle opening control device, 34...Brake control device, 3
5...CPU, 37...ROM139...RAM
. 41・I/O port. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (2)

[Claims] (1) An inclination angle sensor that determines the degree of inclination angle when the vehicle is traveling on a slope, and a vehicle speed sensor that detects the vehicle speed;
Operation means such as a set switch and a resume switch that output operation signals when operated by the driver, and when the vehicle is running on a flat road, enable constant speed driving control at a set vehicle speed when the set switch is operated, and the above-mentioned When the inclination angle sensor exceeds the first reference value, it is determined that the vehicle is running on an uphill road, and after resetting the driving mode to the initial state, when the resume switch is operated, constant speed driving control is performed with the current vehicle speed as the target speed. and if the output of the inclination angle sensor exceeds a second reference value that is greater than the first reference value, the target speed for constant speed driving is changed according to the degree of the inclination angle, and the driving path is a downhill slope. The constant speed driving mode can be continued even if the speed deviation increases and exceeds a predetermined reference value, the mode is switched to deceleration driving mode and the brake pressure is proportionally controlled according to the inclination angle. A vehicle running control device comprising a vehicle speed control means that cancels vehicle speed control after decelerating the vehicle to a safe running speed by using brake control to restore the vehicle to manual mode. (2) In the deceleration driving mode, the vehicle speed control means:
A patent claim characterized in that the fuel cut device is operated when the throttle opening detected by the throttle sensor is below a predetermined value and deceleration to the safe running speed is not possible even after a predetermined period of time has elapsed after the start of brake control. range 1
A travel control device for a vehicle as described in Section 1.