JPS61278427A - Running control device for vehicle - Google Patents

Abstract

PURPOSE:To prevent hunting around the set speed by configurating a device in such a way that the upper and lower limit of the controllable speed range is set so as to allow a vehicle to run at a constant speed based on the set speed, and simultaneously, one of either the upper or the lower limit is corrected depending on the engine operating condition. CONSTITUTION:While a vehicle is running, when a set speed VSSW is turned on so as to allow a constant speed running, a running changeover control block 31 is allowed to store an actual speed VS on that occasion as the set speed VSSW, and is also allowed to store values, in which the specified speed 5km/H, for example, is added to or subtracted from the said actual speed to obtain an upper or a lower limit signal. Then, when an automatic cruise control block 33 is in operation, a value where VS is subtracted from VSS, is stored as a comparison value VSP. Then, a throttle opening correction value is computed by applying a specified factor to the above said comparison value, and a throttle control signal THB2 is corrected so. In addition to those, at least one of either the upper limit or the lower limit is corrected depending on the vehicle running condition as to whether the vehicle is ascending or descending an uphill road.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a travel control device that maintains a vehicle speed at approximately a desired set value while driving the vehicle.

(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. When a difference occurs between the two, the engine throttle valve 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. Considering the purpose of maintaining the vehicle speed within a certain range [1. 'l lets the car coast by disengaging the clutch and cutting off the transmission of driving force between the engine and the wheels.During this period, the engine speed is reduced to idling, allowing fuel-efficient constant-speed driving control. , 1 From this, for example, JP-A-56-2
Publication No. 2113 discloses a vehicle running control in which a predetermined speed range is determined based on the set vehicle speed when a constant speed running condition occurs, and slow acceleration and coasting are repeated between the upper and lower limit values in this range. A method and apparatus are proposed.

Hereinafter, for convenience of explanation, the conventional constant speed driving in which the engine throttle opening (or fuel injection amount) is controlled to maintain the vehicle speed within a certain range will be referred to as autocruise. Constant-speed driving in which the vehicle speed is maintained within a predetermined range by repeating slow acceleration and coasting as proposed above is called economy cruise.

In d3, when the vehicle speed reaches the upper limit, the clutch is disengaged and the engine throttle valve is fully closed to perform coasting, and when the vehicle speed reaches the lower limit, the engine rotation is increased to a rotation corresponding to the vehicle speed. Next, the clutch is engaged and the engine speed is gradually increased to perform gentle acceleration until the vehicle speed reaches the upper limit. For example, if the engine temperature is low and the engine speed is not responsive to throttle opening and closing, When the vehicle speed reaches the lower limit while coasting, it takes time to open the throttle and raise the engine speed to a level corresponding to the vehicle speed, and during this time the vehicle speed falls below the lower limit. There's a problem. The same thing happens when driving uphill.

In other words, since the running resistance is large on an uphill slope, the deceleration of the vehicle speed is large, so when the vehicle speed reaches the lower limit,
There is a problem in that even if an attempt is made to increase the engine rotation to a rotation corresponding to the vehicle speed, the vehicle speed is decelerated during this time and falls below the lower limit value. Furthermore, if the vehicle speed reaches the upper limit while traveling downhill, the opposite phenomenon may occur.

In the above, we have discussed the problems in case 1 of economy cruise, but even in case of auto cruise, control is performed to maintain the vehicle speed within a predetermined range, and the engine temperature is low and responsiveness is affected. Similarly to the above problem, there is a problem in that the vehicle speed fluctuates beyond a predetermined range. In other words, in both economy cruise and auto cruise, in the above cases, the upper and lower limits of vehicle speed within the control vehicle speed range set during constant speed driving may vary depending on engine temperature, driving conditions, etc. There is a problem in that the actual vehicle speed fluctuates beyond these upper and lower limits (in other words, the vehicle speed fluctuates greatly when traveling at a constant speed).

(Objective of the invention) In view of such problems, the present invention has been developed to improve the operating state of the engine (
Regardless of engine temperature, etc.) or driving conditions (whether driving on a hill or not, etc.), the vehicle speed can always be maintained within a certain range while driving at a constant speed, and the fluctuation range of vehicle speed can be kept constant. The object of the present invention is to provide a travel control device that has the following features.

(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 output of the engine to perform constant speed driving, and has a constant speed driving condition detecting means. To detect whether or not the condition has occurred, and to perform constant speed driving when the constant speed driving condition has occurred, use the upper and lower vehicle speed limit setting means to set the vehicle speed within the constant speed range based on the set vehicle speed. The upper and lower limits of the vehicle speed range are set to allow the vehicle to run at a constant speed, while the condition detection means detects engine operating conditions such as engine temperature, or detects driving conditions such as whether or not the vehicle is traveling on a slope. The present invention is characterized in that at least one of the upper limit value and the lower limit value is corrected in accordance with the engine operating state or the running state.

(Implementation/Example) 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.

The elm of this device is performed by controlling the clutch 10 on and off and the throttle actuator 25 to control the opening of the throttle valve 26 based on a signal M from the computer unit 30. The computer unit 30 turns the cruise control switch 30a ON/O.
This is done by the FF, but the computer unit 30 receives signals from the brake switch 2 which detects the operation of the brake pedal 1 in conjunction with the brake pedal 1;
A signal from an accelerator pedal position sensor 4 that detects the amount of depression of the accelerator pedal 3 in conjunction with the accelerator pedal 3, a signal from an engine stop L+1 output sensor 21 that detects whether or not the engine 20 is stopped at the distributor, and cooling of the engine 20. Water temperature sensor 2 that detects water temperature
2, a signal from the throttle position sensor 23 that detects the opening of the throttle valve 26, a signal from the intake air temperature sensor 24 that detects the intake air temperature, and the rotation of the power transmission system on the output side of the clutch 10. Signals from a vehicle speed sensor 16 that detects the speed 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 actuation cylinder 11 to control the engagement and engagement of the clutch 10.
The hydraulic pressure sent from the electric pump 15 via the accumulator 14 is applied to the clutch actuating cylinder 1 by the electromagnetic control valve 13.
1, 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 three points of AlI, and the upper limit value (V + ΔV) and lower limit value (■ + ΔV) of the vehicle speed range in which travel control is performed for the vehicle speed ■ at this time. 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 (V+ΔV). When the vehicle speed reaches the upper limit value (time point 8), the clutch 1o is turned off and at the same time, the throttle is fully opened and the engine rotation is reduced to the 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 (V + ΔV) (point 01), the clutch 10 is turned ON again, and the throttle opening and engine rotation are adjusted to the vehicle speed of this lower limit value. It can be raised as fast as it matches. Thereafter, the throttle opening is gradually opened again, and gradual acceleration is performed until the vehicle speed reaches the upper limit value. Note that, in the present invention, the value of ΔV is corrected according to engine operating conditions such as engine temperature and vehicle running conditions.

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 33, normal cruise control block 3
4. It consists of a throttle opening degree control block 35 and a clutch control block j6.

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 QBR8W 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 AC8W from the cruise switch from the input line 31G, and the cruise method signal EC'M01 from the cruise method switch is from the input line 31d.
), the setting signal vssw from the vehicle speed set switch is input from the input line 31e, and the vehicle speed signal VS 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 (auto cruise) when constant speed driving is selected.
The vehicle speed set switch is a switch for setting the vehicle speed for constant speed travel, and is a switch for switching between constant speed travel (economy cruise) in which slow acceleration and coasting are repeated according to the present invention. A cruise control switch 30a is configured.

A clutch operation permission signal CLUTCH is output to the clutch control block 36 from the output line 31 (from the output line 31h, and a throttle opening control permission signal Tl-l5W is output from the output line 31h to the throttle opening control block 35).

The clutch operation permission signal CLUTCH is an ON/OFF signal, and the clutch control signal CLB on the output line 32d from the economy cruise control block 32 is input to the clutch control block 36 only when the ON signal is output. It is something to do. There are three types of throttle opening control permission signal TH8W: 1.2.3.
When the signal is 1, the signal THB1 from the economy cruise control block 32 is sent via line 32c, when the signal is 2, the signal THB2 from the O1-cruise control block is sent via the line 33C, and when the signal is 3, the signal THB2 is sent from the economy cruise control block 32 via the line 33C.
The signal from the normal control block 34 via THB
3 are respectively input to the throttle opening degree control block 35.

From the output line 31i, a set vehicle speed signal VSS for auto cruise is output to the t-i-cruise control block 33, and from the output lines 31j and 31k, an upper limit value signal VSH and a lower limit value signal VSL of the vehicle speed for economy cruise are output. is output to the 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. The mode signal MOD has three types of signals 1.2.3, and these signals control the above three control blocks 3.
Selectively activate only one of 2.33.34.

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 control signal TLI 81 is output from a line 32G 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.

A mode signal M O is sent to the auto cruise control block 33.
l) In addition to the vehicle speed signal i3V via line 33a
3, the accelerator opening signal is sent via line 33b>E A
CP is input, and a throttle control signal T1[32 is output from the line 33c to the throttle distance control block 35. The L-do signal MO to the normal running control block 34
In addition to D, an accelerator opening signal A is sent via line 34a.
CP is input, and throttle control 01+signal THB3 is output from line 34b to throttle control block 35.

On the other hand, from the throttle opening control block 35, line 3
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.
Do not repeat this flow every time, 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 value signals VSH and VSL are set to zero, and the mode signal MOD and throttle opening control permission signal TH8W are set to 3. and clutch operation permission signal CLUTC
H is turned OFF to perform normal driving control. When the brake is not in operation, the process proceeds to step S4 to determine whether the clutch signal CLSWIfiON is present, and when it is ON, the process proceeds to steps 818 and 819 to shift to normal running control. Next, the process advances to step S7 and the cruise signal AC8W is activated.
is ON or not, and if it is OFF, step 818
, the process proceeds to S19 to shift to normal running control, and when it is ON, the process proceeds to step S8 to determine whether the vehicle speed is 40 KIR/l-1 or less. Since this is performed only when the vehicle speed is 40/h/H or higher in both auto cruise and engineering E1 Nomi Cruise, if the vehicle speed is 401 fIn/H or lower, step 818. Proceed to S19. Vehicle speed 40K
If it is IR/H or higher, the process advances to step S9 and the setting signal v
It is determined whether or not ssw is ON, and when it is OFF, the process advances to step S11 and it is determined whether or not the set vehicle speed signal VSS is greater than zero. This is because the setting signal vssw is only a trigger signal, and if 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 SSW is turned off. This is because even if the setting signal vssw is OF1:, constant speed driving is continued as long as the predetermined value is stored in the setting vehicle speed signal SS. Therefore, when the set vehicle speed signal is zero, the process proceeds to step 818 to shift to normal running control, and when SS>0, the process proceeds to step 813.

On the other hand, when the setting signal vssw is ON, step 81
0 and memorize the actual vehicle speed vS or 1001/l-1, whichever is smaller, as the set vehicle speed signal VSS. This is because constant speed driving over 100/lIR/H is not allowed for safety reasons. ), the value obtained by adding 57 to /H to the set vehicle speed signal VsS is stored as the upper limit signal, and 5/H is stored from the set vehicle speed signal VSS as the lower limit signal.
The value obtained by subtracting fa/H or 407 m/H, whichever is larger, is stored (this is because constant speed running below 407 m/H is not preferred from the viewpoint of stability). Next, set vehicle speed signal ■SS is 40? It is confirmed whether or not the value is equal to or higher than 40KJR/H, and if the value is equal to or lower than 40KJR/H, the process advances to step 818.

On the other hand, when 401 is /H or higher, the cruise method signal E
Determine whether CMOD is ON. The fact that this cruise method signal ECMOD is OFF means that auto cruise is selected, and in this case, step 816
Then, set the mode signal MOD to "2", activate the auto cruise control block 33, set the throttle opening control permission signal TH8W to "2", and turn off the clutch operation permission signal CL tJ 1 CH. Enable auto cruise control. This signal ECMOD is ON
If so, the process proceeds to step 815, where the mode signal MOD is set to ``1'', the economy cruise control block 32 is activated, and the throttle opening control permission signal THSW is set to ``1''.
1” and clutch operation permission No. 15 CL
Oll: UTCH.

Step S15. When S16 or S19 is completed, the process advances to step 5S17, returns to the beginning of the flow after 20 m5 has elapsed, and thereafter repeats this flow every 20 m5.

FIG. 5 is a reflow chart showing the control in the auto cruise control block 33, starting from step s31, starting the 100m5 timer in step 832,
Thereafter, this flow is repeated every 100m5. Next, in step 833, it is determined whether the mode signal MOD is 2'', and only when this is 2'' does the process proceed to the next step 834.

1, that is, this flow does not substantially operate when the mode signal MOD is not "2". In step S34, a value obtained by subtracting the vehicle speed signal VS from the set vehicle speed signal vSS,
In other words, the value corresponding to the difference between the set vehicle speed and the actual vehicle speed is the proportional value V.
The value obtained by subtracting the vehicle speed VLAST in the previous flow (this flow is repeated every 100m5, so the vehicle speed at the time 100m3 ago) from the actual vehicle speed VS is stored as a differential value VSD, and the value of the proportional value VSP is stored as a differential value VSD. 1 depending on the value
0 or -1 is stored as the integral value VSI.

The integral value VSI 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 "-1", which means that the actual vehicle speed is more than 2KIR/H away from the set vehicle speed. In this case, the vehicle speed is brought closer to the set speed more rapidly.

Next, in step 835, predetermined coefficients Kp and K are applied to the proportional value ■SP1, the differential value VSO, and the integral value VSI, respectively.
After multiplying d and Ki, calculate (■5PXKI) - VSD
XKd-K i ) is calculated as the throttle opening correction value THD.

In step 836, this correction (ifTHD is set to J, the throttle control signal IH for correcting the control signal TH82 and bringing the vehicle speed closer to the set vehicle speed) is executed.
Get B2. Furthermore, since this control signal TH32 must be between the throttle opening fully closed (opening 0°) and fully opening 80°, in step S37,
If the signal THB2 is 80” or more, set this to 80°.
When the temperature is below 0°, set this to 0°. Further, in step 838, the current vehicle speed is stored as VLAST, and in step S39, the throttle valve opening FN2 (ACP) calculated from the accelerator opening signal ACP is stored as the actual throttle opening signal TH82B. next,
In step 840, throttle control No. 13 THB2
The signal T H8 calculated in steps 834 to 837 as
2 and the actual throttle opening signal TI-IB2B. 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 this, 1
Wait for 00m5 to pass and return to the beginning of the flow, and then 10m.
Repeat this flow every 0m5.

FIG. 6 is a flowchart showing the control in the economy cruise control block 32, and this flow includes step 85.
1 and in step 852 the mode memory M
Initialize ODM by zeroing it, then step 85
3, start the 20mS timer, and then 20 rT
This flow is repeated for each IS. First, in step 854, it is determined whether or not "P1" is input to the mode signal MOD. If this is other than "1", the process proceeds to steps 867 and 868, and the clutch control signal CLB is input.
is turned ON, and the throttle control signal THB1 is set to zero.

Note that this flow is performed when the mode signal -MOD is 1'', so it can be said that the determination in step 854 is for safety against noise and the like.

Next, in step 858, it is determined whether the mode memory MODM is II II II, and if it is not "1", the process proceeds to step 859, where "1" is set in the acceleration mode signal, and the vehicle speed lower limit value is set based on the lower limit value signal VSL. The function FN (V
This lower limit engine speed signal NEM is obtained from SL) and stored, and the process proceeds to step S60. On the other hand, if the mode memory MODM is 11111, step 86 is executed.
0 and saves the value of mode signal MMOD to mode memory MOD
This is stored in M, but if you set step 859 in the first time of this flow, there is no need to repeat this set in the second flow after 1 as long as the mode memory MODM is 1. It's for a reason.

Next, the process advances to step 861 to output the acceleration mode signal ACC.
This acceleration mode signal 〇〇 is a signal that distinguishes between a slow acceleration state and a coasting state in economy cruise.
' indicates that the vehicle is coasting. The acceleration mode signal ACC is set to ``1'' in step 859. This is because when the economy mode is selected, the vehicle is first slowly accelerated to the upper limit of the set vehicle speed.

When the acceleration mode signal ACC is '1'', step 862
Then, it is determined whether the vehicle speed signal vS is larger than the upper limit value signal VSH1, and when it is smaller than VSH, that is, when 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 (
A predetermined throttle control signal TH81 is obtained from VS). On the other hand, when the vehicle speed reaches the upper limit value and the vehicle speed signal VS is greater than or equal to the upper limit value signal VSH, steps 863 to 865 are performed, the throttle control signal TH81 is set to O'', and the clutch control signal CL
B is turned OFF, the acceleration mode signal ACC is set to ``0'', and the vehicle shifts to coasting.

On the other hand, if it is determined in step 861 that the acceleration mode signal ACC is "OII", that is, the coasting state is established, the process proceeds to step 870 and subroutine Δ is executed. FIG. 7 is a flowchart showing subroutine A of step S70. , here after entering step 871,
At step 872, J5 outputs the difference between the medium speed signal VS and the memory vehicle speed signal VSM stored when this routine was last activated, that is, the rate of change in vehicle speed DVS. Next, in step 873, it is determined whether or not this change rate DvS is negative, that is, whether or not the vehicle speed is decreasing. If this is positive or zero (vehicle speed increases or remains unchanged), coasting is continued as it is. If so, proceed to step 384.

On the other hand, if the rate of change DVS is negative, step 874
Numerical number FNG according to the rate of change of lever DVS (Figure 8A)
A correction coefficient KVS of the lower limit value VSL is obtained from the equation. In addition, in this flow, the correction coefficient KvS is expressed as the vehicle speed change rate DvS.
However, instead of this, it may be determined depending on the engine water temperature or the slope of the slope, as shown in FIG. 8B.

Next, in step 875, the lower limit signal VSL is corrected by this correction coefficient KvS, and this corrected value is compared with the vehicle speed signal, and the vehicle speed signal VS is determined to be the correction value (VSLXKVS
), the process advances to step 884 to continue coasting.

When the vehicle speed signal vS is smaller than the correction value, step 87
Proceed to step 6 to determine the herring rotation N corresponding to the corrected lower limit signal.
The throttle is opened to increase the engine speed to EM, and after the actual engine speed signal NE reaches NEM in step 877, the process proceeds to step 878, where the clutch control signal CLB is turned ON to connect the clutch. Next, in order to proceed to slow acceleration, step S79
In steps 880 to 883, the throttle opening degree THBB necessary for slow acceleration from the vehicle speed VSL is determined.
You can hear the throttle opening by Δθ every 0m5, and gradually open the throttle to THBB.

After the above flow, in step 884, the current vehicle speed signal S is stored as a memory vehicle speed signal VSM, the process proceeds to step 885, this subroutine A is ended, and the process returns to the flow shown in FIG. 6 and proceeds to step S69.

After the above flow, in step S69, wait for the passage of 20 m 5 and return to step 853, and the following 20 m 3
Repeat this flow every time.

FIG. 9 is a flowchart showing the control in the normal running control block 34. The routine starts at step 890, and in step 591 it is determined whether the mode signal MOD is "3". When the mode signal MOD is not "3", the control by this flow is unnecessary, so the throttle M control signal TH83 is set to zero and this flow ends.On the other hand, when the mode signal MOD is 3", the accelerator is activated in step 893. The throttle control signal TH83 is obtained from the function FN2 (ΔCP) for obtaining a necessary throttle control signal according to the opening signal ACP, and this flow ends.

FIG. 10 is a flowchart showing the control in the throttle opening control block 35, starting from step 8101, starting the 20m5 timer in step 5102, and then in steps S103 to 5107, the throttle opening control permission signal TH8W is set to li TT ,
1f11 or 11311, and when TH8W=1, throttle control signal T181 is stored as actuator signal Tl-108j, and when Tl-13W=2, TH82 is stored as actuator signal THOBj. , when TH8W=3, THB3 is stored as the 7-unit factory signal THO[3j. Next, in step 8108, the actuator signal THOBj is output to the actuator 25,
The opening and closing of the throttle valve 26 is controlled so that the opening degree is determined by this signal THOBj. After this, step 510
9, wait for 20 m5 to pass, and repeat this flow every 20 m5.

FIG. 11 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 5123, where the clutch actuator 13 is turned off and the clutch is connected, and this flow ends. On the other hand, if the permission signal CLUTCH is ON, the process advances to step 5124 and the clutch control signal e CL
13 is ON or not, and this signal CLB is OFF.
Notogi is in a coasting state and the actuator 13 is turned on.
When the signal CL8 is ON, it is in a slow acceleration state and the clutch actuator 13 is turned OFF.
to avoid engaging the clutch.

Although this embodiment shows an example in which only the lower limit value is corrected, it is a matter of theory that the upper limit value may be corrected.

Furthermore, although this embodiment has been described in the case of economy cruise, in the case of auto cruise, there is no control to cause coasting, and the other similar controls may be performed.

(Effect of 'R, light) As explained above, according to the present invention, when performing constant speed driving, the upper and lower limits of the control 11 vehicle speed range are set based on the C1 set vehicle speed. At the same time, at least one of these upper and lower limits is corrected depending on the engine operating condition or the vehicle driving condition, so when the engine temperature is low and engine response is poor, or when going uphill (downhill). The deceleration of the vehicle while driving (
By correcting the upper or lower limit value, the actual vehicle speed can always be maintained within a predetermined range even when the acceleration (acceleration) is large. improves.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram that does not show the overall configuration of the 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; ! I is a block diagram showing the configuration of a computer unit used in the above-mentioned travel control device, and FIGS. Figure 4 shows the travel switching control block,
Fig. 5 shows the auto cruise control block, Fig. 6 shows the economy cruise control block, Fig. 9 shows the normal cruise control block, and Fig. 10 shows the throttle uu degree i! i+ control block, FIG. 71 shows control in the clutch control block,
FIG. 7 is a flowchart showing the control in subroutine A of FIG. 6, and FIGS. 8A and 8B are graphs showing the modification coefficient of the lower limit signal with respect to the vehicle speed change rate J3 and the engine water temperature, respectively. 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)

[Claims] 1) A driving control device that controls engine output based on a set vehicle speed signal input from the outside, maintains the vehicle speed within a certain range around the set vehicle speed, and performs 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 the upper and lower limits of a control vehicle speed range for driving at a constant speed; a state detecting means for detecting the operating state of the engine or the running state of the vehicle; and the state detecting means A driving control device for a vehicle, comprising: a correction means for correcting at least one of an upper limit value and a lower limit value set by the upper and lower limit vehicle speed setting means in response to the output of the upper and lower limit vehicle speed setting means. 2) The vehicle running control device according to claim 1, wherein the state detection means is a means for detecting engine temperature. 3) The correcting means receives the state and the engine temperature detected by the detecting means, and corrects the lower limit value to be larger when the engine temperature is low. A travel control device for a vehicle according to scope 2. 4) The state detecting means is a means for detecting whether the vehicle is traveling uphill or downhill. The vehicle travel control device according to item 1. 5) The state detection means is a means for detecting deceleration of the vehicle, and when the detected deceleration is larger than a predetermined value, the correction means makes a correction to increase the lower limit value. A vehicle travel control device according to claim 1.