JPS6261833A - Travel control device for vehicle - Google Patents

Abstract

PURPOSE:To hold an average speed of actual speed at a set vehicle speed with a high degree of accuracy, by providing such an arrangement that the difference between an upper limit which is set by an upper and lower vehicle speed limit setting means and the set vehicle speed is greater than that between the set vehicle speed and a lower limit. CONSTITUTION:The supply amount of fuel for an engine 20 is controlled to effect a moderate acceleration until the speed of a vehicle increases from a lower limit to an upper limit which are set within a constant speed travel range by a computer 30 with reference to a set vehicle speed unit 2, and therefore, when the vehicle speed reaches the upper limit, a clutch 10 is energized to cut off the transmission of drive power to wheels so that inertial travel is carried out until the vehicle speed decreases to the lower limit. In this case, setting is made such that the difference between the upper limit and the set vehicle speed is greater than that between the set vehicle speed and the lower limit. With this arrangement, control may be made such that an averaged vehicle speed during travel at a constant speed approaches the set speed, thereby it is possible to realize travel control with a high degree of accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a travel control device that maintains a vehicle speed at approximately a desired set value and causes the vehicle to travel.

(Prior Art) In recent years, constant speed traveling devices that automatically maintain the vehicle speed of an automobile at a desired speed set by a driver have been put into practical use. This constant speed traveling device sets the vehicle speed as a target value for constant speed traveling by a set operation by the driver when the vehicle speed reaches a desired vehicle speed, and thereafter compares this set vehicle speed with the actual vehicle speed. Therefore, when a difference occurs between the two, the throttle valve of the engine is controlled according to the difference, thereby making the actual vehicle speed match the set vehicle speed.

In order to drive at a constant speed using such a device, it is necessary to always maintain the throttle valve opening at a predetermined opening so as to maintain the engine rotation corresponding to the set vehicle speed. When the vehicle speed is within a certain range, the clutch is disengaged to cut off the transmission of drive power between the engine and the wheels, causing the vehicle to coast, and during this time the engine is reduced to idle speed. By doing so, constant speed driving control with good fuel efficiency can be performed.

For this reason, for example, Japanese Unexamined Patent Publication No. 56-22113 proposes that a predetermined speed range is determined based on the set vehicle speed when a constant speed running condition occurs, and that the speed is set between the upper and lower limits in this range. 2. Description of the Related Art Vehicle travel control methods and devices have been proposed in which acceleration and coasting are repeated.

In this driving control, when the vehicle speed reaches the upper limit value, the clutch is disengaged and the engine throttle valve is fully opened to cause coasting. When the vehicle speed reaches the lower limit value, the engine rotation is increased to the rotation corresponding to the vehicle speed, and then the clutch is released. is connected to control υj to gradually increase the engine speed and perform gentle acceleration until the vehicle speed reaches the upper limit value, and maintain the vehicle speed within a certain range determined by the upper and lower limit values to maintain constant speed driving. .

When performing such constant speed driving control, the upper and lower limit values are set with a constant width above and below the set vehicle speed, but this width is set to the same width above and below the set vehicle speed (for example, Set the vehicle speed to 801/H and move this width up and down by 5Ks.
/I-1, upper limit is 85-/H1 lower limit is 75/!
llI/H), there is a problem that the average vehicle speed during constant speed driving is lower than the set vehicle speed. The first reason why this happens is that running resistance is proportional to the square of the vehicle speed, so the speed reduction rate during coasting near the upper limit is greater than the speed reduction rate near the lower limit. The second reason is that when the vehicle speed reaches the lower limit during coasting and the clutch is engaged to increase the engine speed and perform slow acceleration, there is a slight time delay before the transition from coasting to slow acceleration. It is due to something.

(Objective of the Invention) In view of the above circumstances, the present invention is designed to accurately maintain the average value of the actual vehicle speed at the set vehicle speed when the vehicle speed is kept constant by repeating slow acceleration and coasting and the vehicle is driven at a constant speed. It is an object of the present invention to provide a travel control device that can perform control.

(Structure of the Invention) The driving control device of the present invention is a device that maintains the vehicle speed within a predetermined range near the set vehicle speed by controlling the amount of fuel supplied to the engine to perform constant speed driving, and has a constant speed driving condition detection means. detects whether or not a constant speed running condition is occurring, and when the constant speed running condition occurs, when driving at a constant speed, the upper and lower vehicle speed limit setting means sets the constant speed running vehicle speed based on the set vehicle speed. An upper limit value and a lower limit value within the range are set, and the fuel supply amount to the engine is controlled by the slow acceleration means until the vehicle speed reaches the upper limit value from the lower limit value to perform slow acceleration.
When the vehicle speed reaches the upper limit, the coasting means activates a clutch, etc. to cut off the transmission of driving force from the engine to the wheels, allowing the vehicle to coast until the vehicle speed reaches the lower limit, resulting in constant speed driving. In this case, the upper and lower limits are set so that the difference between the upper limit and the set vehicle speed is greater than the difference between the set vehicle speed and the lower limit.

(Embodiments) Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the overall configuration of a travel control device according to the present invention.

This device is controlled by controlling the clutch 10 on and off and controlling the opening of the throttle valve 26 by the throttle actuator 25 based on signals from the computer unit 30. computer unit 3
0 is ON/OFF of cruise control switch 30a
The computer unit 30 receives a signal from the brake switch 2 that is linked to the brake pedal 1 to detect the operation of the brake pedal 1, and a signal that is linked to the accelerator pedal 3 to detect the amount of depression of the accelerator pedal 3. A signal from the accelerator pedal position sensor 4 to detect, a signal from the engine stop detection sensor 21 to detect whether or not the engine 20 is stopped at the distributor,
A signal from the water temperature sensor 22 that detects the cooling water temperature of the engine 20, a signal from the throttle position sensor 23 that detects the opening degree of the throttle valve 26, a signal from the intake air temperature sensor 24 that detects the intake air temperature, and an output from the clutch 10. Signals from a vehicle speed sensor 16 that detects vehicle speed based on the rotation of the power transmission system on the side are input, and actuation signals are output to the throttle actuator 25 and the electromagnetic control valve 13 based on these input signals. The electromagnetic control valve 13 controls the hydraulic pressure supply to the clutch actuating cylinder 11 to control the engagement and disengagement of the clutch 10, and the hydraulic pressure sent from the electric pump 15 via the accumulator 14 is applied to the clutch actuating cylinder by the electromagnetic control valve 13. 11, the rod 11a is moved to either the left or right in the figure, and the clutch 10 is engaged or engaged via a lever 12.

FIG. 2 is a graph showing changes over time in vehicle speed, engine rotation, etc. when the travel control device performs travel control. This graph shows changes when the cruise control switch 30a is turned on at time A, and the upper limit (■+ΔVl) and lower limit (■ −ΔV2
) is determined, and from this state, the engine throttle opening degree is gradually opened and gradual acceleration is performed until the vehicle speed reaches the upper limit value (■+ΔV1). When the vehicle speed reaches the upper limit 8
At this point in time), the clutch 10 is turned OFF, and at the same time, the throttle opening is fully closed, the engine rotation is reduced to idling rotation, and the vehicle coasts in this state. During coasting, the vehicle speed gradually decreases due to running resistance, etc., and when this vehicle speed reaches the lower limit value (■-ΔV2) (at time C), clutch 1
゜ is turned ON again, and the throttle opening is increased to a speed that matches the engine speed with this lower limit value of the vehicle speed. Thereafter, the throttle opening is gradually opened again, and gradual acceleration is performed until the vehicle speed reaches the upper limit value.

When performing this control, the permissible vehicle speed variation range ΔV1. for determining the upper limit value and lower limit value. Δv2 is ΔVl>Δv
2. This means that the vehicle speed is the lower limit 1i1
(V-ΔV2) (at time C), clutch 10JE
: When turning ON and increasing the throttle opening, there is a slight delay in operation as shown in the figure, so there is a time delay in Δ before transitioning to slow acceleration, and the relationship between vehicle speed and running resistance during coasting. From the relationship, the vehicle speed decrease rate (α1) near the upper limit is equal to the vehicle speed decrease rate (α2) near the lower limit.
), the average vehicle speed during constant speed driving becomes lower than the median value between the upper limit value and the lower limit value. is lower than the median of the upper and lower limits, and the set vehicle speed V and the average vehicle speed are brought as close as possible to achieve accurate travel controllability. Note that the permissible vehicle speed fluctuation widths Δ■1 and ΔV2 are set in consideration of the fact that when the vehicle speed is high, even if the vehicle speed is increased, the driving feeling is less likely to be impaired. ΔV2 may be changed depending on the vehicle speed.

FIG. 3 is a block diagram showing the configuration of the computer unit 30. The computer unit 30 includes travel switching control blocks 31. Economy cruise control block 32. Auto cruise control block 331 Normal driving control block 3
4. Throttle opening control block 35 and clutch [
It consists of 36 0 blocks.

The travel switching control block 31 has input lines 31a to 31.
f and output lines 310-31k are connected. The input line 31a receives the brake signal BR5W from the brake switch 2, and the input line 31b receives the clutch signal CLS from the clutch switch that detects clutch operation.
W is the cruise signal j3AcsW from the cruise switch from the input line 31G, and the cruise method signal ECMOD from the cruise method switch is from the input line 31d.
However, the setting signal vssw from the vehicle speed set switch is input from the input line 31e, and the vehicle speed signal ■S from the vehicle speed sensor 16 is input from the input line 31f. The cruise switch is a switch that switches between normal driving and constant speed driving, and the cruise method switch switches between conventional constant speed driving (hereinafter referred to as auto cruise) and slow acceleration according to the present invention when constant speed driving is selected. This switch switches between constant-speed driving (hereinafter referred to as economy cruise), which repeats coasting and constant-speed driving.The vehicle speed set switch is a switch to set the vehicle speed for constant-speed driving, and these switches control the cruise control shown in Figure 1. A switch 30a is configured.

The output line 310 outputs a clutch operation permission signal @CLtJTC1-1 to the clutch control block 36, and the output line 31h outputs a throttle opening control permission signal TH8W to the throttle opening control block 35. The clutch operation permission signal CLIJTCH is an ON/OFF signal, and allows the clutch control signal CLB on the output line 32d from the economy cruise control block 32 to be input to the clutch control block 36 only when the ON signal is output. It is. Throttle opening control permission signal T)-18W has three types of signals: 1, 2.3,
When the signal is 1, the signal TH81 is sent from the economy cruise control block 32 via the line 32G, when the signal is 2, the signal TH82 is sent from the auto cruise control block via the line 33C, and when the signal is 3, the signal TH82 is sent from the auto cruise control block via the line 34b. The signals Tl-lB5 from the normal control block 34 are respectively input to the throttle opening control block 35.

From the output line 311, a set vehicle speed signal vSS for auto cruise is output to the auto cruise control block 33, and from the output lines 31j and 31k, an upper limit value signal VSH and a lower limit value signal V of the vehicle speed for economy cruise are output.
SL is output to economy cruise control block 32. Output line 311 outputs a mode signal MOD to economy cruise control block 32. It is output to the auto cruise control block 33 and the normal running control block 34. There are three types of mode signals MOD, 1.2.3, and these signals control the three control blocks 32.
Only one of 33 and 34 is selectively activated.

In addition to the signals from lines 31i and 311 mentioned above, the economy cruise control block 32 also has an input line 32
Engine speed signal NE from a and line 32b
Based on these signals, a throttle ti control signal TH81 is output from a line 32c to a throttle opening control block 35, and a clutch control signal CLB is output from a line 32d to a clutch control block 36.

Mode signal MOD to auto cruise control block 33
In addition, a vehicle speed signal vS is input via line 33a, an accelerator opening signal ACP is input via line 33b,
A throttle I control signal TH82 is output from the line 33C to the throttle distance control block 35. In addition to the mode signal MOD, an accelerator opening signal ACP is inputted to the normal running control block 34 via a line 34a, and a throttle control signal TH83 is outputted to the throttle opening control block 35 from a line 34b.

On the other hand, crawling in 3 from the throttle opening control block 35
5a to output the operating signal to the throttle actuator 25 to operate the throttle valve 26, and output the operating signal from the clutch control block 36 to the electromagnetic control valve 13 via the crawler 36a to operate the clutch actuating cylinder 11 and The clutch is actuated via a lever 12.

The control operation of the computer unit 30 configured as above will be explained with reference to the flowchart shown below.

FIG. 4 is a flowchart showing the control in the travel switching control block 31, starting from step S1, starting the 20m5 timer in step S2, and then starting the 20m5 timer.
This flow is repeated every time, and then step S
3, it is determined whether the brake signal BR8W is ON or not. When this is ON, that is, when the brake is being depressed, the process proceeds to steps 818 and 819, where the set vehicle speed signal VSS, upper and lower limit signals VSH and VSL are set to zero, and the mode signal MOD and throttle opening control permission signal Tl-18W are set. is set to 3, and the clutch operation permission signal CLU
Turn off the TCH and perform normal driving control. When the brake is not operating, the process proceeds to step S4, and it is determined whether the clutch signal CLSW is ON or not. If it is ON, the process proceeds to step 818.S19 to shift to normal running control, while when it is OFF, the process proceeds to step S5. It is determined whether the reset switch is turned on or not, and when it is turned on, flag 2 is set to zero. This reset switch is used to return the engine to economy cruise mode when the engine stops during coasting and the clutch is engaged to switch to auto cruise control.
When the flag 2 is set to zero, the economy cruise control is performed again. Then, step S
Proceed to step 7 and determine whether the cruise signal AC8W is ON or not.
When it is OFF, proceed to steps 818 and 819 to transition to normal running 11JIII, and when it is ON, step S8
Then, it is determined whether the vehicle speed is equal to or less than 401/H. Vehicle speed is 40/C for both auto cruise and economy cruise.
Since this is done only when the vehicle speed is equal to or higher than m/H, step 81 is executed when the vehicle speed is equal to or less than 401/)-1.
8. Proceed to 819. When the vehicle speed is 40K11/H or higher, the process advances to step S9 to determine whether the setting signal vssw is ON or not. When it is OFF, the process advances to step 811 to determine whether the set vehicle speed signal VSS is greater than zero. This is because the setting signal VSSW is only a trigger signal, and once the vehicle speed setting for constant speed driving is set when the setting signal vssw is sent, it will remain unchanged even if the setting signal vssw is turned OFF. This is because the setting message @v
Even if ssw is OFF, constant speed driving is continued as long as a predetermined value is stored in the set vehicle speed signal SS. Therefore, when the set vehicle speed signal is zero, step S1
The routine advances to Step 8 to shift to normal running control, and when VSS>O, the routine advances to Step 313.

On the other hand, when the setting signal vssw is ON, step S1
0 and memorize the smaller of the actual vehicle speed vS or 100KJR/H as the set vehicle speed signal VSS. This is to prevent constant speed driving of 1007m/H or higher for safety reasons.) , store the value obtained by adding 5-/H to this set vehicle speed signal ■SS as the upper limit signal,
As the lower limit signal, store the value obtained by subtracting 3&/H from the set vehicle speed signal VSS or 401fa/H, whichever is greater (this is because constant speed driving below 40KA/H is not desirable from the viewpoint of stability). be). That is, in this embodiment, the difference between the upper limit value and the set vehicle speed is set to be 21 m/H larger than the difference between the set vehicle speed and the lower limit value. Then,
Check whether the set vehicle speed signal SS is 40KMZH or higher, and
If it is less than 0&/H, proceed to step 818 and set 40KI.
If it is R/H or higher, it is determined whether flag 2 is set to 1 or not. Setting flag 2 to 1 means that the engine is stopped during coasting and the clutch is connected. At this time, the auto cruise mode is entered, so proceed to step 816 and set the mode signal MOD to II 211.
to operate the auto-cruise control block 33, set the throttle opening control permission signal TH8W to 2'', and turn off the clutch operation permission signal CLLITC)-1.On the other hand, when flag 2 is not set to 1, It is determined whether the cruise method signal ECMOD is ON.If the cruise method signal ECMOD is OFF, it means that auto cruise is selected. When this signal ECMOD is ON, the process proceeds to step 815, where the mode signal MOD is set to 1'' to operate the economy cruise control block 32, the throttle opening control permission signal TH8W is set to 1'', and the clutch operation is performed. Turn on the permission signal CLLITCH.

Step S15. When S16 or 819 is completed, the process advances to step 8817, waits for 20 m5 to elapse, returns to the beginning of the flow, and thereafter repeats this flow every 20 m5.

FIG. 5 shows i in the auto cruise control block 33,
In the flowchart showing the II control, starting from step S31, a 100m5 timer is activated in step 332, and thereafter this flow is repeated every 100m5. Next, in step 833, the mode signal MOD is set to "2".
Determine whether or not, and only when this is 2'', proceed to the next step 8.
Proceed to 34.

That is, in this flow, the mode signal MOD is II 2 I
It does not substantially operate when the value is other than +. Step S34
, the value obtained by subtracting the vehicle speed signal VS from the set vehicle speed signal SS, that is, the value corresponding to the difference between the set vehicle speed and the actual vehicle speed, is stored as a proportional value vSP, and the vehicle speed VLAST in the previous flow is calculated from the actual vehicle speed VS (this flow is repeated every 100 m5, so the value obtained by subtracting the vehicle speed at the time 100 m5 before is stored as the differential value VSD, and 1°O or -1 is stored as the integral value VSI depending on the value of the proportional value VSP.

The integral 11Vs T is 1 when the proportional value VSP is 2 or more.
”, when the proportional value VSP is 2 or less and 12 or more, it is O”, and when it is -2 or less, it is l II II, so when the actual vehicle speed is 2Ks/H or more away from the set vehicle speed. The vehicle speed is made to approach the set vehicle speed more rapidly.

Next, in step 835, predetermined coefficients Kp and K are applied to the proportional value VSP, differential value VSD, and integral value VSI, respectively.
After multiplying d and Ki, the operation (VspxKp-VSDX
Kd-K i ) and obtain this as the throttle opening correction value THD.

In step 836, the throttle control signal TH82 is corrected using the correction value THD to obtain a throttle control signal TH82 for bringing the vehicle speed closer to the set vehicle speed. Furthermore, this control signal TH82 is applied to the fully closed throttle opening (
The opening must be between 0' and 80°, so in step 837, when the signal TH82 is 80° or more, it is set to 80°, and when it is below 0°, it is set to Oo. do. Furthermore, in step 838, the current vehicle speed is stored as VLAST, and in step S3
In step 9, the throttle valve opening FN2 (ACP) calculated from the accelerator opening signal ACP is stored as the actual throttle opening signal TH82B. Next, step S40
In step 8, the throttle control signal THB2 is
The larger one of the signal 1-IB2 shut out in steps 34 to S37 and the actual throttle opening signal TH82B is selected. This is so that when the driver depresses the accelerator pedal in an attempt to accelerate the vehicle while the vehicle is running at a constant speed, the throttle opening degree is further increased in response to the driver's depressing the accelerator pedal to accelerate the vehicle. After that, wait for 100 m5 to pass and return to the beginning of the flow, and repeat this flow every 100 m5 thereafter.

FIG. 6 is a flowchart showing υj′n in the economy cruise control block 32. This flow starts from step 851, initializes the mode memory MODM by zeroing it in step 852, and then starts the 20m5 timer in step 853. 20m or less
This flow is repeated every 5 minutes. First, in step 854, it is determined whether or not ``1'' is input to the mode signal MOD. If this is other than ``1'', the process proceeds to steps 875 and 876, where the clutch control signal CLB is turned ON and the throttle control signal is Set THBI to zero. Note that this flow is performed when mode signal @MOD is II.
Since this is at the time of I11, it can be said that the determination in step S54 is for safety against noise and the like.

Next, in step S55, the engine speed signal N
It is determined whether or not E is smaller than the engine stall determination rotation signal NFL, and the presence or absence of the engine stall is determined.

When it is smaller than the engine stall determination rotation signal NFL,
In other words, when the engine is stalled, flag 1 is set to II 111.
is set, and when it is larger than NFL, that is, when the engine is not in a stalled state, flag 1 is set to 0. Thereafter, in step 858, it is determined whether the mode memory MODM is "1", and if it is not 01, the process advances to step S59. Input 1'' into the acceleration mode signal, and obtain this lower limit engine speed signal NEM from the function FN (VSL) that calculates the engine speed using gear ratio etc. to obtain the lower limit value of the vehicle speed based on the lower limit value signal VSL and store it. Then proceed to step 860. On the other hand, when the mode memory MODM is "1", the process directly proceeds to step 860, and the mode signal M
The value of OD is stored in the mode memory MODM, but if the setting in step 859 is performed in the first time of this flow, it is necessary to repeat this set in the second and subsequent flows as long as the mode memory MODM is 1. This is because there is no.

Next, the process advances to step 861 to output the acceleration mode signal ACC.
Determine whether or not is °′1″. This acceleration mode signal A
CC is a signal that distinguishes between a slow acceleration state and a coasting state in economy cruise, and when it is II I H, it is a slow acceleration state, and when it is '0', it is a coasting state. Mode signal ACC is “1”
This is because when the economy mode is selected, the vehicle is first gently accelerated to the upper limit of the set vehicle speed.

When the acceleration mode signal ACC is "1", step S62
Then, it is determined whether the vehicle speed signal vS is larger than the upper limit value signal vSH, and if it is smaller than VSH, that is, if the vehicle speed has not yet reached the upper limit value, the current vehicle speed is determined from the relationship between the vehicle speed and the throttle opening. Function FN2 to find the throttle opening required to perform gentle acceleration against
A predetermined throttle control signal THBI is determined from s).

On the other hand, when the vehicle speed reaches the upper limit value and the vehicle speed signal S is greater than or equal to the upper limit signal VSH, steps 863 to 865 are performed, the throttle control signal THB1 is turned on, and the clutch control signal CLB
is turned OFF, the acceleration mode signal ACC is set to "OII", and the vehicle shifts to coasting.

On the other hand, if it is determined in step 861 that the acceleration mode signal ACC is 0'', that is, the coasting state is established, the process proceeds to step 867 and the vehicle speed signal vS is set to the lower limit value signal V.
It is determined whether or not it is smaller than SL. Lower limit signal VSL
If it is larger, continue coasting as it is,
If it is equal to or greater than the lower limit signal VSL, the process proceeds to steps 868 to S70, where a signal α that opens the throttle opening by a predetermined amount is input to the throttle control signal TH81, and the engine speed signal NE at this time and step 859 are input. The difference NEI from the lower limit engine speed signal NEM calculated in is calculated, and it is determined whether the absolute value of this difference NEI is smaller than a predetermined minute value β. If the difference NEI is greater than β, the signal α is increased by a minute amount Δα, and steps 368 to S70 are repeated. That is, this will open the throttle valve cleanly until the engine rotation reaches the lower limit of the set vehicle speed, which corresponds to the value.After this, steps 372 to 874 are performed, the clutch control signal is turned ON, and the speed is adjusted to the current vehicle speed. Function FN2 (
VS) to obtain a predetermined throttle control signal TH81,
Set the acceleration mode signal to "1".

After the above flow, in step 377, wait for 20 m5 to elapse, and then return to step 853, and repeat this flow every 20 m5.

FIG. 7 is a flowchart showing the control in the normal running control block 34, starting from step S90, and in step 891, it is determined whether the mode signal MOD is 3". When the mode signal M○D is not "l 3 n" Since control by this flow is not necessary, the throttle control signal T)-183 is set to zero and this flow ends. On the other hand, when the mode signal MOD is 113 II, step S9
3, the throttle control signal TH83 is obtained from the function FN2 (ACP) for obtaining a necessary throttle control signal according to the accelerator opening signal ACP, and this flow ends. FIG. 8 is a flowchart showing $131111 in the throttle opening control block 35, and step $1
Starting from 01, the 20m5 timer is activated in step 5102, and then in steps $103 to $5107, the throttle opening control permission signal TH8W is set to ``1'',
In addition to determining whether it is “2'' or “3”,
T)-18W-1 when the throttle control signal THBI
is stored as the actuator signal THOBj, and TH
When 8W-2, TH82 is actuator signal THO
When the signal is TH8W-3, TH83 is stored as the actuator signal THOBj. Next, in step 8108, the actuator signal THO
Bj is output to the actuator 25, and this signal THOB
The opening and closing of the throttle valve 26 is controlled so that the opening degree is determined by j. After this, in step 5109, 20 m
5, and repeat this flow every 20m5.

FIG. 9 is a flowchart showing control in the clutch control block 36. This flow starts from step 5121, and in step 5122, it is determined whether the clutch operation permission signal CLUTCH is ON, that is, whether or not it is economy cruise. If it is not the economy cruise, the process proceeds to step 5124, where the clutch actuator 13 is turned off, the clutch is connected, and this flow ends. On the other hand, when the permission signal CLLJTCI-1 is ON, the process advances to step 5123 and the clutch control signal CLB
When this signal CLB is OFF, it is in a coasting state and the actuator 13 is turned ON to disengage the clutch, and when the signal CLB is ON, it is in a slow acceleration state and the clutch actuator 13 is OFF. to connect the clutch and end this flow.

(Effects of the Invention) As explained above, according to the present invention, when economy cruise is selected, slow acceleration and coasting are repeated within a predetermined vehicle speed range, thereby achieving constant speed driving with relatively low fuel consumption. In general, the difference between the upper limit value and the set vehicle speed is made larger than the difference between the set vehicle speed and the lower limit value, so that the average vehicle speed while driving at a constant speed is close to the set vehicle speed. It is possible to perform accurate driving control.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall configuration of a cruise control device according to the present invention; FIG. 2 is a graph showing changes over time in vehicle speed, engine rotation, etc. when the cruise control device performs cruise control; FIG. 3 4 is a block diagram showing the configuration of a computer unit used in the above-mentioned travel control device; FIGS. 4 to 9 are flowcharts showing the control contents of each control block of the computer unit; FIG. 5 shows the auto cruise control block, FIG. 6 shows the economy cruise control block, FIG. 7 shows the normal cruise control block, FIG. 8 shows the throttle opening control block, and FIG. 9 shows the clutch control block. 1... Brake pedal 3... Accelerator pedal 1
0...Clutch 11...Clutch operation cylinder 13...Solenoid control valve 16...Vehicle speed sensor 22
... Water temperature sensor 25 ... Throttle actuator 26 ... Throttle valve

Claims (1)

[Scope of Claims] A driving control device that controls the amount of fuel supplied to an engine based on a set vehicle speed signal input from the outside, and maintains the vehicle speed within a certain range around the set vehicle speed to perform constant speed driving. a constant speed driving condition detecting means for detecting whether or not a constant speed driving condition occurs; upper and lower limit vehicle speed setting means for setting an upper and lower limit value of vehicle speed within the range; and a slow acceleration device for performing slow acceleration driving by controlling the amount of fuel supplied to the engine until the vehicle speed reaches the upper limit value from the lower limit value. and a coasting means that cuts off the transmission of driving force from the engine to the wheels when the vehicle speed reaches the upper limit value and causes the vehicle to coast until the vehicle speed reaches the lower limit value; A driving control device for a vehicle, characterized in that a difference between the upper limit value set by the setting means and the set vehicle speed is larger than a difference between the set vehicle speed and the lower limit value.