JPH07108626B2 - Constant speed traveling device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant speed traveling device for automatically traveling a vehicle at a desired constant speed.

(Prior Art) A constant-speed traveling device (auto cruise device) that automatically travels a vehicle at a set speed (target vehicle speed) is known in order to reduce the burden on the driving operation when the vehicle travels at a constant speed.

FIG. 1 shows the configuration of a constant-speed traveling device, in which a vehicle reaches a desired speed with a speedometer (not shown) after turning on a main switch 1 for selecting an automatic cruise mode in order to perform an automatic cruise operation. When the set switch 2 is manually operated (turned on) to set the target vehicle speed (auto cruise speed), the controller 3 sets the target vehicle speed and the vehicle speed from the vehicle speed sensor 4 based on a predetermined control law. The opening of the throttle valve 6 is controlled via the throttle drive circuit 5 according to the deviation from the signal, and the engine 10
Adjust the output of to maintain the target vehicle speed. When the driver depresses a brake pedal (not shown), the stop lamp switch 7 interlocked with the petal and also having a function as a cancel switch is turned on, and the auto cruise operation is canceled. After that, when the resume switch 8 is turned on, the automatic cruise operation is restarted. Also,
An inhibit switch 9 is provided which works in conjunction with a shift lever (not shown) of the automatic transmission 11 and acts as a cancel switch. The automatic transmission 11 is in the neutral shift position and the driving force from the engine 10 is not transmitted to the wheels. At this time, the automatic cruise operation is canceled to prevent the engine 10 from blowing up.

Also, if the resume switch 8 is continuously pressed during the auto cruise operation, the vehicle is accelerated and the resume switch 8
A new target vehicle speed can be set to the vehicle speed at the time when the finger is released from, or the vehicle is decelerated by pressing and holding the set switch 2 during auto cruise operation, and the vehicle speed at the time when the finger is released from the set switch 2 It is also known that the target vehicle speed can be set.

Reference numeral 14 is a throttle valve opening sensor that detects the valve opening of the throttle valve 6, and reference numeral 15 is a hydraulic control circuit that switches the shift stage of the automatic transmission 11 according to a shift command signal from the controller 3 during auto cruise. is there.

The shift stage switching by the automatic transmission 11 is divided by the throttle opening and the vehicle speed, and a shift diagram that defines the shift stage to be established is set in advance. From this shift diagram, the throttle valve opening and the vehicle speed are set. When the operating state in which gear shifting is to be performed is detected by each of the detected values, the gear shift is performed to the required gear.

On the other hand, the conventional constant speed traveling device configured as described above,
When a predetermined shift condition is satisfied during the auto-cruise operation, regardless of the above-mentioned shift diagram, the shift command signal for downshifting from 4th speed to 3rd speed or upshifting from 3rd speed to 4th speed is issued as described above. Hydraulic control circuit of automatic transmission 11
I output it to 15 and tried to change the gear. The conditions for outputting the shift-down command are that the vehicle is in the process of being accelerated (ACC) by continuously pressing the resume switch 8 during auto-cruise operation and accelerating the vehicle at a constant acceleration. A shift-up command signal for upshift is issued, such as that the resume (RES) process for restarting the cruise operation is in progress, the vehicle speed is lower than the target vehicle speed by a predetermined value or more during the cruise operation, and that state continues for a predetermined time or longer. Is output for a predetermined time (for example,
5 seconds), a predetermined time (for example, 3 seconds) has elapsed after the RES process is completed, and a predetermined time (for example, 20 seconds) has elapsed since the vehicle speed returned to within a predetermined value from the target vehicle speed. It is the case.

(Problems to be Solved by the Invention) Since the conventional constant speed traveling device outputs the shift command signal to the automatic transmission 11 when the above condition is satisfied, the shift timing may be delayed, The driving feeling was bad because an extra shift was performed. In particular,
When climbing a long uphill that was neither in ACC processing nor in RES processing, the shift timing was delayed and the driving feeling was bad.

The present invention has been made to solve such a conventional problem, and outputs a shift-up command or a shift-down command at an optimum timing to perform a natural shift, thereby improving driving feeling. An object is to provide a high speed traveling device.

(Means for Solving the Problems) According to the present invention in order to achieve the above-mentioned object, a gear position that is divided according to a throttle valve opening degree of an internal combustion engine and a vehicle speed and is established during normal traveling is defined. The first shift diagram to be set is set in advance, and based on the first shift diagram,
During constant-speed running control of a vehicle equipped with an automatic transmission that switches to a required gear according to the vehicle speed detection value and the throttle valve opening detection value, the throttle valve opening is maintained so that the vehicle speed is close to the target vehicle speed. In the constant speed traveling device controlled in accordance with the second shift, the second shift is defined according to the target throttle valve opening and the vehicle speed calculated to be the target vehicle speed, and defines the shift speed to be established during the constant speed traveling control. A diagram is set in advance, and during the constant speed traveling control, the second shift diagram is used instead of the first shift diagram, and the gear shift should be performed based on the second shift diagram. There is provided a constant speed traveling device characterized in that, when an operating state is detected, a shift command signal is output to the automatic transmission device to shift to the diagram to be established.

(Operation) The gear shift command signal output by the constant speed traveling device is output when the operating state in which gear shifting is to be performed is detected based on the second shift diagram. If the first shift diagram is set so as to be suitable for the constant speed traveling control, the shift stage can be switched at the optimum timing during the constant speed traveling control.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

The constant-speed traveling device in this embodiment is applied to a vehicle equipped with an automatic transmission, and its configuration (hardware) is
Since there is substantially no difference from the one shown in FIG. 1 and only the control program (software) adopted by the controller 3 is different, the description of the configuration will be omitted, and when necessary in the following description. Refer to FIG.

First, a vehicle speed control method executed by the device of the present invention will be described. When the target vehicle speed (auto cruise speed) V ₀ is set by turning on the main switch 1 and the set switch 2, the controller 3 first selects a control law to be applied in the vehicle speed control. FIG. 2 is a flow chart showing a control law selection procedure executed by the controller 3. The controller 3 first reads the vehicle speed V detected by the vehicle speed sensor 4 and then the vehicle speed deviation ΔVk (Vo between the target vehicle speed Vo and the vehicle speed V). = Vo-V) is calculated (step S1). Then, it is determined whether or not the absolute value of the vehicle speed deviation ΔVk is greater than or equal to a predetermined determination value ΔV _KP (for example, 8 to 3 km / hr) (step S2), and if it is greater than or equal to P (constant acceleration) control is executed. (Step S3).

If the determination result in step S2 is negative (No), the deviation Δ
The absolute value of Vk is the predetermined discriminant value ΔV _KF (for example, 5 to 1 km / hr)
It is determined whether or not the following (step S5). When this determination result is negative, that is, when the absolute value of the deviation ΔVk indicates a value between the determination value ΔV _KP and the determination value ΔV _KF , PID control is executed (step S6), and when the determination is affirmative (Yes), Fuzzy control is executed (step S7).

FIG. 3 shows the control law regions selected as described above, and these control law regions are selected only by the deviation ΔVk as is apparent from the above description.

Next, fuzzy control, which is a control law executed when the deviation ΔVk is small, is described, which is executed in step S7 described above.
In fuzzy control, four rules are set in advance, one of these rules is selected, and the valve opening of the throttle valve is controlled according to the selected rule. To explain this in more detail, first, the four rules are as follows.

Rule 1. If the deviation ΔVk is negative, close the throttle valve 6 small.

Rule 2. If the deviation ΔVk is positive, open the throttle valve 6 small.

Rule 3. If the acceleration A is positive, close the throttle valve 6 largely.

Rule 4. If acceleration A is negative, open throttle valve 6 wide.

In selecting these rules, first, the vehicle speed deviation ΔVk and the acceleration A are calculated. The vehicle speed deviation ΔVk is calculated by the same method as shown in step S1 of FIG.
The acceleration A is calculated by the following equation.

A = ΔVk−ΔVk−1 (1) where ΔVk is the deviation calculated this time, and ΔVk−1 is the deviation calculated last time.

Next, using the calculated deviation ΔVk and acceleration A, membership function values μ _{1 to} μ ₄ are calculated from the membership function set corresponding to each rule. 5 to 8
The figure is a graph of membership functions set corresponding to the respective rules 1 to 4, and the function value μ ₁ calculated by the membership function shown in FIG.
The vehicle speed V is a predetermined value ΔV _KS1 (for example, 1 to 3k) from the target vehicle speed Vo.
m / hr) a value between a low value and a predetermined value ΔV _KS1 high value, it increases linearly as the vehicle speed V increases,
It is set to a value between 0 and 1. Then, the vehicle speed V is the target vehicle speed Vo.
When the value is smaller than the predetermined value ΔV _KS1 , the minimum value is set to 0, and when it is larger than the predetermined value ΔV _KS1 , the maximum value is set to 1. Similarly, the function value μ ₂ calculated by the membership function shown in FIG. 6 is when the vehicle speed V is between the value that is smaller than the target vehicle speed Vo by the predetermined value ΔV _KS1 and the value that is larger by the predetermined value ΔV _KS1. , Decreases linearly as the vehicle speed V increases, and is set to a value of 1 to 0. When the vehicle speed V is less than the target vehicle speed Vo by a predetermined value ΔV _KS1, it is set to the maximum value 1, and when it is more than the predetermined value ΔV _KS1 , it is set to the minimum value 0. . The function value μ ₃ calculated by the membership function shown in FIG. 7 is a predetermined value −A _L1 (eg −
0.1 to −1.0 km / hr / sec) and a predetermined positive value A _L1 (for example, 0.1
.About.1.0 km / hr / sec), the value increases linearly as the acceleration A increases, and is set to a value of 0 to 1. Then, when the acceleration A is less than or equal to the predetermined value −A _L1 ,
The minimum value is set to 0, and when it is equal to or _larger than the predetermined value A _L1 , the maximum value is set to 1, respectively. The function value μ ₄ calculated by the membership function shown in FIG. 8 depends on the increase of the acceleration A when the acceleration A is a value between the negative predetermined value −A _L1 and the positive predetermined value A _L1. It decreases linearly and is set to a value of 1-0. When the acceleration A is less than or equal to the predetermined value −A _L1 , the maximum value is 1. When the acceleration A is greater than or equal to the predetermined value A _L1 , the minimum value is 0.
Are set respectively.

Membership function values μ _{1 to} μ ₄ are calculated using these membership functions, and the rule with the largest membership function value is selected. Various modifications can be considered for the membership functions shown in FIGS. 5 to 8, and it is not always necessary to set the maximum and minimum membership function values to the same value for each membership function.

Next, the drive throttle amount Δθ is calculated according to the selected rule. This drive throttle amount Δθ is calculated from the graphs shown in FIGS. 9 to 12 which are set corresponding to each rule. For example, if the membership function value μ ₁ is maximum and rule 1 is selected, the drive throttle amount Δθ ₁ is calculated from FIG. 9 corresponding to FIG. In the case of the graph shown in FIG. 9, when the membership function value μ ₁ has the maximum value 1, the drive throttle amount Δθ ₁ is the predetermined value −Δθ _S1.
(For example, -0.01 to -0.05V), when the minimum value 0 is set, the predetermined value Δθ _S1 is set, and the maximum value 1 and the minimum value 0
When taking a value between _{1 and 2} , the membership function value μ ₁ is set to a value that linearly increases from the predetermined value −Δθ _S1 to the predetermined value Δθ _S1 as the membership function value μ ₁ decreases.

When rule 2 is selected, the drive throttle amount is calculated from FIG. 10, and in the case of FIG. 10, there is an inverse relationship to that of FIG.
When the membership function value μ ₂ is the maximum value 1, the drive throttle amount Δθ ₂ is set to the predetermined value Δθ _S1 , and when the minimum value is 0, it is set to the predetermined value −Δθ _S1 .

When the rules 3 and 4 are selected, the drive throttle amount is calculated from FIGS. 11 and 12, respectively. From the graph of FIG. 11, when the membership function value μ ₃ is the maximum value 1,
The drive throttle amount Δθ ₃ is a predetermined value −Δθ _L1 (for example, 0.
02-0.08V), and when the minimum value is 0, the predetermined value Δ
Set to θ _L1 . From the graph of FIG. 12, it can be seen that the driving throttle amount Δθ ₄ when the membership function value μ ₄ is the maximum value 1.
Is set to a predetermined value Δθ _L1 , and when the minimum value is 0, it is set to a predetermined value −Δθ _L1 . The predetermined value Δθ _L1 is the predetermined value Δθ
It is set to a value larger than _S1 .

The membership functions shown in FIGS. 9 to 12 can be modified in various ways, and the maximum and minimum values of the membership function do not necessarily have to be set to the same value for each membership function.

In this way, the calculated drive throttle amount Δθ ₁ ~
Substituting Δθ ₄ into Δθ into the following equation (1), the target throttle θ _n is calculated.

θ _n = θ _n-1 + K _G × Δθ (2) where θ _n-1 is the current throttle valve opening, that is,
This is the previously set target throttle opening, and K _G is a coefficient (non-linear gain) set according to the target throttle opening θ _n (actually, the previously set target throttle opening θ _n-1 is used). ). FIG. 4 shows a function of the target throttle opening θ _n and the coefficient K _G, and the target throttle opening θ
_n is a voltage (V) corresponding to the valve opening signal of the throttle valve 6 detected by the throttle valve opening sensor 14,
For example, when the target throttle opening θ _n is 0, a predetermined value
At K _G0 (for example, 0.1 to 1.0), the target throttle opening θ _n
Is θ _n1 (for example, 2.5 V), each is set to a predetermined value K _G1 (for example, 4 to 5). In setting the coefficient K _G, the throttle valve opening signal Vth detected by the throttle valve opening sensor 14 may be used instead of the above-mentioned target throttle opening θ _n .

As described above, in the vehicle speed control based on the fuzzy control law, a rule is selected by which the acceleration A or the vehicle speed deviation ΔVk should be emphasized by the membership function value, and the driving throttle amount Δθ is calculated according to the selected rule. , The driving throttle amount Δθ is multiplied by the coefficient K _G set according to the current target throttle amount, and the current throttle amount θ _n-1 is added to this product value, so that the driving range from high to low Stable control can be executed up to the area.

Next, the control law, that is, the PID control, executed when the vehicle speed deviation ΔVk has a medium magnitude, which is executed in step S6 described above, will be described.

First, the target throttle opening degree θ _n of the throttle valve 6 and the current driving throttle amount Δθ of the throttle drive circuit 5 in the PID control law are calculated by the following equations (3) and (4).

_{θ n = θ n-1 +} Δθ ...... (3) Δθ = K I × (Vo-V) + K P × (Ao-A) ...... (4) Here, θ _n-1 is driving the throttle amount of up to the last The coefficients K _I and K _P in the above equation (4) are both set according to the vehicle speed, and FIGS. 13 and 14 show the relationship between the coefficients K _I and K _P and the vehicle speed V, respectively. Show these coefficients K _I and K
_P is set to a value that rapidly increases as the vehicle speed V increases.

On the other hand, the target acceleration Ao is the vehicle speed V, the deviation ΔVk and the acceleration A.
Is set in the following manner. First, the acceleration ao is set from the relationship between the acceleration ao and the vehicle speed V shown in FIG. The relationship between the acceleration ao and the vehicle speed V shown in FIG.
The acceleration ao decreases linearly with the increase of
Is 0, a predetermined value a ₀₁ (for example, 2.5 km / hr / sec) is set, and when a predetermined speed V _a0 (for example, 120 km / hr) or more,
It is set to 0 respectively. Then, the target acceleration Ao is set from the obtained acceleration ao as shown in the table below.

The method of setting the acceleration a ₀ is not limited to the one obtained from the relationship shown in FIG. 15, and various modifications can be considered.

When the valve opening of the throttle valve 6 is controlled by the target throttle amount θ _n obtained as described above, the target acceleration Ao
Is set according to the vehicle speed V, and the coefficients (gains) K _I and K _P are also set according to the vehicle speed V. Therefore, the vehicle speed V is not temporarily held at a constant value, and the target vehicle speed V is set. It smoothly and rapidly shifts toward the vehicle speed Vo, and the driving feeling is good.

Next, the control rule executed when the deviation ΔVk is large, that is, the P (constant acceleration) control, which is executed in step S3, will be described. The drive throttle amount Δθ in P control is calculated by the following equation.

Δθ = K _G × (K _P × (Ao−A) + Do) (5) Here, K _P is a constant (gain), Ao is the target acceleration, and A is the acceleration detection value. Then, Do is a correction variable for correcting the torque that increases or decreases as the engine speed increases or decreases, and is given as a function of the engine speed. Generally, when the throttle opening is fixed and the engine speed increases, the torque decreases. Therefore, Do is set to a value that corrects the decrease in the torque. K _G is a coefficient (non-linear gain) set according to the target throttle opening θ _n , and is set according to the target throttle θ _n from the graph shown in FIG. 4 as described above.

As described above, in the P control, the correction variable Do is used to previously correct the torque change due to the increase or decrease of the engine speed, and the driving throttle Δθ is changed using the coefficient K _G that changes according to the target throttle θ _n. Therefore, the acceleration can be kept constant and stable, and a good feeling can be obtained.

Next, the procedure for outputting the shift command signal from the constant speed traveling device of the present invention during the automatic cruise to shift down the automatic transmission 11 from the fourth speed to the third speed will be described with reference to the flowchart shown in FIG. To do.

First, the controller 3 determines in step S10 whether or not the automatic cruise is in progress. If this determination is negative, the controller 3 of the constant speed traveling device does nothing and this 4-3
The execution of the shift determination routine ends. Meanwhile, step
If the determination result in S10 is affirmative, the controller 3 proceeds to step S11 and determines whether or not the gear should be shifted to the third gear.

FIG. 17 is used for the determination in step S11 and is stored in the storage device built in the controller 3 in advance.
FIG. 3 is a three-shift diagram, in which a shift speed operation region that defines a shift speed to be established is divided according to a target throttle opening and a vehicle speed. The 4-3 shift diagram is set on the assumption that the vehicle travels on an inclined road having a predetermined inclination, and is also applied to the case where the vehicle travels on a flat road. Also,
A broken line shown in FIG. 17 is a 4-3 shift diagram applied in the automatic transmission 11, and a 4-3 shift diagram in the automatic transmission 11 is shown.
The determination of 3 shifts is made based on the vehicle speed V and the actual throttle opening θ _th .

The controller 3 detects the vehicle speed V detected by the vehicle speed sensor 4.
And the target throttle opening θ set as described above
_The gear stage to be established is discriminated according to _n, and in the case of the fourth speed region, that is, in the case where the determination result of step S11 is negative, the discrimination routine is ended, and in the case of the third speed region, that is, of step S11. If the determination result is fixed, a 4-3 shift command signal is output to the hydraulic control circuit 15 of the automatic transmission 11 to switch the shift speed to the 3rd speed. As is obvious from Fig. 17,
Even if the actual throttle opening θ _th is in the shaded area in the figure, if the target throttle opening θ _n is in the shaded area, the shift command signal from the controller 3 is prioritized to switch to the third speed.

The shift of the automatic transmission 11 according to the shift command signal of the present invention is performed by the ACC process or the RES, like the conventional shift command during constant speed control.
Since the gear is not changed immediately during the processing, no extra shift is performed. In addition, when the vehicle is climbing a long uphill without accelerating (ACC) or resuming (RES), the conventional constant-speed traveling device does not output the gear change command signal. Therefore, the shift is performed after the actual throttle opening θ _th exceeds the broken line in FIG. 17 and shifts to the third speed range. In such a shift, the shift timing is delayed, but in the constant speed traveling device of the present invention, the shift timing delay is eliminated.

Next, a procedure for outputting a shift command signal from the constant speed traveling device of the present invention during the automatic cruise to shift up the automatic transmission 11 from the third speed to the fourth speed will be described with reference to the flowcharts shown in FIGS. 18 and 19. It will be described with reference to FIG.

First, the controller 3 determines in step S20 whether or not the automatic cruise is in progress. If this determination is negative, the controller 3 of the constant speed traveling device does nothing and the controller 3-4
The execution of the shift determination routine ends. Meanwhile, step
If the determination result in S20 is affirmative, the controller 3 proceeds to step S21 and executes a throttle opening estimation routine. This routine is for estimating the throttle opening θ ₃ required to maintain the target vehicle speed Vo when the shift speed is switched from the 3rd speed to the 4th speed.

FIG. 19 shows the details of the throttle estimation routine. First, the controller 3 holds the current throttle opening θ ₂ and can maintain the vehicle speed V when traveling on a flat road with an inclination of 0% at the third speed. ₁ is estimated using the operation diagram shown by the solid line in FIG. 20 (step S210). In this case, the current throttle opening θ ₂ may be the actual throttle opening θ _th detected by the throttle valve opening sensor 14 or the target throttle opening θn set by the above-mentioned control law. Also,
The operating line shown by the solid line in Fig. 20 is the standard operating condition of the vehicle,
In other words, shows a relationship between the throttle opening and the vehicle speed when the vehicle travels a normal flat road (inclination 0%) at a predetermined load weight, flat road at the current throttle opening theta ₂ from the operating line The vehicle speed V ₁ is estimated when the vehicle travels. It should be noted that the operating lines for the third speed and the operating speed for the fourth speed when traveling on a flat road are close to the operating lines shown by the substantially solid lines, and therefore each of these operating lines is represented by a solid line. Further, if the traveling path is inclined, a load corresponding to the degree of inclination is applied to the vehicle, so that the operating line moves in the direction of the arrow from the operating line shown by the solid line. For example, as indicated by the broken line in FIG. 20, the current throttle opening θ ₂ and the vehicle speed V (assuming that the vehicle is traveling at substantially the target speed Vo) are used to drive the vehicle on the slope currently traveling at the third speed. Can be estimated, the deviation between the vehicle speed V ₁ and the target speed Vo (V ₁ −Vo)
Can be considered as the load caused by the inclination of the road.

Next, the above-mentioned deviation (V ₁ −Vo) was obtained at the 3rd speed. Converted to the deviation ΔV corresponding to the tilt load when traveling at the 4th speed by the following equation (6). Yes (step S211).

ΔV = (V ₁ −Vo) / R4 (6) Here, R4 is a constant (for example, 0.70). Then, the vehicle speed V ₂ that can be maintained at the 4th speed on the road having the current throttle opening of 0% incline is calculated by the following equation (7) (step S212).

V ₂ = Vo + ΔV (7) Then, from the vehicle speed V ₂ calculated by the equation (7) and the operation line shown by the solid line in FIG. 20, it is necessary to maintain the vehicle speed V ₂ on the slope of 0%. Estimate the throttle opening θ ₃ (step S2
13), this routine ends.

Returning to step S21 in FIG. 18, after obtaining the throttle opening θ ₃ estimated as described above, the controller 3 determines whether to shift to the fourth speed (step S2
2).

FIG. 21 is used for the determination in step S22 and is stored in the storage device which is built in the controller 3 in advance.
It is a shift diagram, and a shift speed operation region that defines a shift speed to be established is divided according to a throttle opening and a vehicle speed. Incidentally, this 3-4 shift diagram is also set on the assumption that the vehicle travels on an inclined road having a predetermined degree of inclination like the 4-3 shift line during auto cruise shown in FIG. It is also applied when traveling on a flat road. Also, the 21st
The broken line shown in the figure applies to the automatic transmission 11 3
4 is a line obtained by converting the -4 shift diagram by the throttle opening estimation method (a diagram used when substantially no auto cruise is executed).

The controller 3 detects the vehicle speed V detected by the vehicle speed sensor 4.
And the estimated throttle opening θ set as described above
_The gear stage to be established is determined according to _3, and if the third speed range, that is, if the determination result in step S22 is negative, the determination routine is ended, and if the fourth speed range, that is, in step S22. If the determination result is affirmative, a 3-4 irregularity command signal is output to the hydraulic control circuit 15 of the automatic transmission 11 to switch the shift speed to the 4th speed.

Even when it is determined that the shift stage is switched by the automatic transmission 11 using the 3-4 shift diagram shown by the broken line in FIG. 21 during the automatic cruise, the shift command signal from the controller 3 is prioritized and is shaded in the figure. In the operating region shown, the gear is held at the third speed. Further, FIG. 21 also shows the 4-3 shift line, which is used for the shift discrimination by the automatic transmission 11 and is shown by the broken line in FIG.

The shift of the automatic transmission 11 according to the shift command signal of the present invention is performed by the ACC process or the RES, like the conventional shift command during constant speed control.
Since the shift is not performed after waiting for a predetermined time after the processing is completed, the shift is performed immediately when the gear range changes,
It is not held in the third gear for a long time,
The driving feeling is improved.

The shift change and the throttle opening θth when a vehicle during an auto cruise in which the target speed Vo is set to 100 km / hr travels on a long uphill slope, the conventional constant speed traveling device and the constant speed traveling of the present invention are used. Comparing the devices, FIGS. 22 and 23 show the conventional constant-speed traveling device, and FIGS. 24 and 25 show the vehicle speed when the constant-speed traveling control is performed by the constant-speed traveling device of the present invention. V shows the time variation of the inclination of the traveling path, and the time variation of the changed gear and the throttle opening θth.

In the conventional constant-speed traveling device, although the throttle opening θth becomes large, it is difficult to shift to the third speed and
The throttle opening θth at time t1 shown in FIG. 23 is first switched to the third speed. Then, when the engine output has a margin due to the shift to the third gear and the throttle opening θth is closed, it is immediately switched to the fourth gear, and therefore the throttle opening θth is opened again. t1 and t2
Between the time points, the shift between the third speed and the fourth speed is repeated in a short time, and during that time, the vehicle speed V fluctuates and the driving feeling is deteriorated.

On the other hand, in the constant speed traveling device of the present invention, based on the shift line during the auto cruise shown in FIGS. 17 and 21, the throttle opening θth is set to 3 before the wide opening as in the conventional constant speed traveling device. Shift down to the speed is executed (t10 in Fig. 25).
After the throttle opening θth becomes sufficiently small, the shift up to the fourth speed stage is executed (at time t11 in the figure), during which the vehicle speed V is maintained at the substantially target speed Vo for a short time. The opening and closing of the throttle valve 6 and the extra shift operation are not performed. Therefore, a smooth and natural gear shifting operation is performed, and a good driving feeling can be obtained.

The control law for setting the target throttle opening θ _n during auto cruise is not limited to that of the embodiment.
Various conventionally known control rules can be applied.

(Effects of the Invention) As described in detail above, according to the constant speed traveling device of the present invention,
A second shift diagram that is divided according to the target throttle valve opening calculated to reach the target vehicle speed and the vehicle speed is defined, the shift speed to be established is defined, and the second shift diagram applied during auto cruise is set in advance. When an operating state in which gear shifting is to be performed is detected based on the second shift diagram during auto cruise, the gear shift command signal is output to the automatic transmission to shift to the gear stage to be established. It is possible to eliminate the inconveniences such as extra gear shifting operation being repeated during automatic cruise and delaying gear shifting timing, and to obtain a good driving feeling.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a constant speed traveling device according to the present invention, FIG. 2 is a flowchart showing a control law selecting procedure executed by the controller 3 shown in FIG. 1, and FIG. FIG. 5 is a diagram showing a control law region divided by a vehicle speed deviation ΔVk, FIG. 4 is a graph showing a relationship between a target throttle θ _n and a coefficient K _G, and FIGS. 5 to 8 are membership functions. Is a graph of the membership function set corresponding to the rule selected when the deviation ΔVk is negative, and FIG. 6 is the membership function set corresponding to the rule selected when the deviation ΔVk is positive Of FIG. 7, FIG. 7 is a graph of the membership function set corresponding to the rule selected when the acceleration A is positive, and FIG. 8 corresponds to the rule selected when the acceleration A is negative. Graph of set membership functions, No. 9 It includes a membership function value mu ₁ obtained from the graph of FIG. 5, a graph showing the relationship between the driving throttle amount [Delta] [theta] ₁ to thereby set, FIG. 10, the membership obtained from the graph of Figure 6 Function value μ
₂ is a graph showing the relationship between the driving throttle amount Δθ ₂ and the driving throttle amount Δθ ₂ which is set by the membership function value μ ₃ obtained from the graph of FIG. Graph showing the relationship with ₃ , No. 12
The figure shows the membership function value μ ₄ obtained from the graph of FIG. 8 and the drive throttle amount Δθ set by the membership function value μ _4.
4 is a graph showing the relationship with FIG. ₄ , FIG. 13 is a graph showing the relationship between the coefficient (gain) K _I applied in the PID control law according to the present invention and the vehicle speed V, and FIG. 14 is applied in the PID control law according to the present invention. 15 is a graph showing the relationship between the coefficient (gain) K _P and the vehicle speed V, FIG. 15 is a graph showing the relationship between the target acceleration ao and the vehicle speed V, and FIG. 16 is executed by the controller of the constant speed traveling device 4 -3 Flowchart of shift determination routine, FIG. 17 is a graph showing a 4-3 shift operation region divided by the vehicle speed V and the target throttle opening θn, and FIG. 18 is executed by the controller of the constant speed traveling device 3- Four
FIG. 19 is a flowchart of a shift determination routine, FIG. 19 is a flowchart of a throttle opening estimation routine executed by the controller, and FIG. 20 is an operation line represented by vehicle speed and throttle opening. A graph for explaining the procedure for obtaining the estimated value of the opening, FIG. 21 is a graph showing a 3-4 shift operation region divided by the vehicle speed and the throttle opening, and FIGS. 22 and 23 are long uphills. A vehicle that climbs at a constant speed of a target speed of 100 km / hr is controlled at a constant speed by a conventional constant speed traveling device, and the speed is controlled by a conventional method. The vehicle speed V, the inclination of the traveling path, the throttle opening, Fig. 24 and Fig. 25 are graphs showing changes with time of the shift, and Figs. 7 is a graph showing changes in vehicle speed V, inclination of a road, throttle opening, and shift with time. 2 ... Set switch, 3 ... Controller, 4 ... Vehicle speed sensor, 5 ... Throttle drive circuit, 6 ... Throttle valve, 8 ... Resume switch, 10 ... Internal combustion engine, 11 ... Automatic transmission, 14 ...... Throttle valve opening sensor, 15 ...... Hydraulic control circuit (gear stage switching means).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takeshi Nishimura 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Yasunori Miyata 5-33-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Keihito Inagaki 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation

Claims (1)

[Claims] Claim: What is claimed is: 1. A first shift diagram which is divided according to a throttle valve opening degree of an internal combustion engine and a vehicle speed and which defines a shift stage to be established during normal traveling is set in advance, and the first shift diagram is set. Based on the diagram, the throttle valve opening is controlled so that the vehicle speed is close to the target vehicle speed during constant speed running control of a vehicle equipped with an automatic transmission that switches to the required gear according to the vehicle speed detection value and the throttle valve opening detection value. In the constant-speed traveling device that is controlled so as to be held at a predetermined speed, the gear position is defined according to the target throttle valve opening and the vehicle speed that are calculated to be the target vehicle speed, and the gear stage that should be established during the constant-speed traveling control is defined. The second shift diagram is set in advance, and the second shift diagram is used instead of the first shift diagram during the constant speed traveling control. Based on the When constant speed running device, characterized in that to shift the shift instruction signal in the diagram to be the established output to the automatic transmission.