JPH0558193A - Constant-speed driving control device for vehicle - Google Patents

Abstract

PURPOSE:To provide a constant-speed driving control device for vehicle which can converge on a target car-speed with a constant convergence along a given track all the time against fluctuation in vehicle dynamic characteristics due to change in gear position or driving load using time delay control. CONSTITUTION:An actual car speed at the time of setting is set as a target car speed by a target value setting circuit 122. And a target track car speed for giving a reference track is calculated by a target track setting means 123, and a control amount to an actuator 126 is calculated by a control amount calculating means 125 so that a deviation between the actual car speed and the target track car speed is zero. When the deviation between the target track car speed and the target car speed falls below a predetermined value, acceleration in converging on the target car speed is changed to a smaller value by a convergent acceleration changing means 124, and resume response without overshoot is enabled at convergence.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A conventional vehicle constant-speed traveling control device detects an actual vehicle speed with a vehicle speed sensor, sets a target vehicle speed according to the intention of a driving vehicle, and controls the target vehicle speed so that the actual vehicle speed converges to the target vehicle speed, for example. V (s) / U (s) = b / s + a (s is the Laplace operator, V (s)
Is a vehicle speed, U (s) is an actuator command voltage, a is an unknown characteristic, b is an unknown input distribution characteristic), and various feedback control systems based on PID control are used to configure a constant speed. Driving control is performed. At this time, the dynamic characteristics of the vehicle change due to changes in gears, changes in running load, that is, changes in slope, changes in air resistance, changes in vehicle weight, etc., and convergence to the target vehicle speed is always maintained. It will not be constant and will be different.

Therefore, regardless of the change in the vehicle dynamic characteristics,
In order to obtain a certain degree of convergence to the target vehicle speed, it is necessary to adjust multiple control gains that calculate the amount of operation to the actuator that drives the throttle valve, in accordance with changes in gears and changes in running load. , This adjustment requires a lot of labor. For example, as described in Japanese Patent Application Laid-Open No. 1-153344, the operation amount to the throttle valve is calculated by P + IP + D control, and the current throttle opening and the throttle opening required for steady running on level ground are calculated. The running load is calculated from the difference between the running load and the forward control system P +
Negative feedback control system P +
By reducing the proportional constant and the differential constant of D, the convergence to the target vehicle speed is made constant regardless of the difference in running load, and it is intended to realize good constant speed running control.

[0004]

However, in the conventional constant speed traveling control device based on the feedback control such as the P + I-P + D control, the operation required for the controlled object is as follows. This is a PTP (Point to Point) operation in which the target point (vehicle speed) moves from a fixed point to a fixed point. That is, the guaranteed operation is only the transition operation between two points from the vehicle speed during a certain traveling to the set target vehicle speed, and is not suitable for CP (Continuous Path) operation in which the target point moves continuously. There is a problem. That is, the followability is not guaranteed for the target trajectory until the vehicle speed converges to the target vehicle speed, and therefore, in any state, the convergence is always constant, that is, the same target trajectory. Converging along is very difficult with conventional PID control. Also, when trying to expand the control target to a wider range of vehicle types,
Depending on the vehicle type of the vehicle to be installed and the like, depending on the vehicle type, there are trajectories that can be followed and trajectories that cannot be followed, and it is difficult to generate an appropriate trajectory with the same software for each vehicle. Was.

Further, the above structure alone has the following problems. In one vehicle type, the input distribution characteristic b of the controlled object fluctuates 2-3 times due to the fluctuation of the running load, etc., but it can be tracked by appropriately switching each constant of PID, that is, the control gain. It is possible to obtain a control input that operates with good performance and stability. However, if the same control software is used to expand the controlled object not only to one vehicle type but also to multiple vehicle types, the control gain developed for one vehicle type can make the control output of other vehicle types follow the target track well. However, the conventional PID control has a problem that it is very difficult to make the control gain variable for various vehicle types and configure a robust control system.

The present invention has been made by paying attention to the above-mentioned conventional problems, and introduces the concept that the fluctuation of a minute time is constant, and a kind of adaptive control for estimating an unknown term, that is, By using the time delay control, the target response waveform trajectories when the vehicle speed converges to the target vehicle speed are given several times by a function of time, and the error vector is defined with reference to the given trajectories as a reference Provided is a vehicle constant-speed traveling control device capable of constantly converging to a target vehicle speed along a given trajectory with a constant convergence even when the vehicle dynamics change due to changes in step position and traveling load. The purpose is to do. Further, by providing a plurality of target trajectories in advance, the driver can select a desired response and provide a constant speed traveling control device for a vehicle, which enables constant speed traveling control suitable for the riding feeling of each driver. With the goal. Furthermore, to provide a vehicle constant-speed traveling control device capable of switching the settling time of a target track when the actual vehicle speed converges to the target vehicle speed, depending on the magnitude of the deviation between the actual vehicle speed and the target vehicle speed when the resume is turned on. With the goal. Further, the present invention constructs and mounts a rule for correcting the target trajectory according to the limit capacity of each vehicle type by the deviation between the actual vehicle speed and the target track vehicle speed or the differential value of this deviation and the average speed and position of the actuator. It is an object of the present invention to provide a constant speed traveling control device for a vehicle, which can always obtain an appropriate target trajectory suitable for a vehicle type. Further, the actual input distribution characteristic b in the controlled object is unknown, on the other hand, when the control input characteristic best which is the control gain in the controller is not appropriate, based on the qualitative relationship between the input and the output, A rule is constructed to change the control input characteristic best, which is necessary for the control amount calculation, based on the deviation or the differential value of the deviation and the average speed and position of the actuator. Then, by observing this changed behavior of best, the maximum value that best can take, that is, the initial value at the time of set and resume ON
An object of the present invention is to provide a constant-velocity traveling control device for a vehicle in which the variation range of the control input characteristic best is narrowed down by updating best0, and the output of the controlled object of the one-input one-output system follows the target trajectory well. ..

[0007]

To achieve the above object, the present invention provides a vehicle speed detection circuit for detecting the actual vehicle speed of a vehicle, a target value setting circuit for setting a target vehicle speed according to the driver's will, and a time value setting circuit. The target trajectory setting means for giving one target trajectory vehicle speed at the time of resume as a function, and the control amount to the actuator for driving the throttle valve so that the actual vehicle speed converges to the target vehicle speed along the target trajectory vehicle speed, the vehicle speed detection Using the vehicle speed detected by the circuit and the target track vehicle speed, a track-following time
And a control amount calculating means for calculating according to the delay control control law.

The target trajectory setting means is provided with a plurality of normalized target trajectories when the vehicle speed converges to the target vehicle speed, and a target trajectory selecting means for allowing the driver to select a desired response. It has a different configuration. Further, the above-mentioned means has a return vehicle speed deviation detecting means for detecting a deviation between the target vehicle speed and the actual vehicle speed at the time of resume, and the convergence time of the target trajectory can be switched according to the detected value.

In the above means, the input variable is at least one of the deviation between the target track vehicle speed and the actual vehicle speed or the differential value of the deviation, the average speed and position of the actuator, and the output variable is the new target track vehicle speed. , A target trajectory correcting means for newly obtaining a target trajectory vehicle speed by using one or more trajectory correcting rules, an input variable being at least one of a deviation between the target trajectory vehicle speed and an actual vehicle speed or a differential value of the deviation, and an actuator The average speed and position, the output variable is the control input characteristic best which is a calculation coefficient in the control amount calculation means,
The control input characteristic best using one or more coefficient determination rules
And a control input coefficient determining means for determining
Further, depending on the change state of the control input characteristic best, coefficient width correction means for determining the initial control input characteristic best0 and the minimum value best1 of the control input characteristic which are the maximum value of the control input characteristic at the time of setting or resume, and a set At the time of resuming, an initial control input amount U (0) is calculated by using the initial control input characteristic best0.

Further, in the target trajectory setting means, one target trajectory vehicle speed at the time of resume is given as a function of time by a return acceleration α representing the inclination at the time of convergence at the time of resume, and the target trajectory correction means inputs it. A variable is at least one of the deviation between the target track vehicle speed and the actual vehicle speed or a differential value of the deviation, and the average moving speed and position of the actuator, and the output variable is the value of the return acceleration α that gives the target track vehicle speed, one or more Using the acceleration correction rule of 1, the return acceleration α at the time of resume is newly obtained, and when the actual vehicle speed converges to the target vehicle speed at the time of resume, the acceleration giving the target track vehicle speed is changed to obtain a smoothly converged target track. Convergence acceleration changing means is provided. further,
An initial target trajectory change means is provided for measuring the vehicle speed deviation from the time of resume ON and changing the target track vehicle speed so as to become the actual vehicle speed at that time when it exceeds a set value.

[0011]

According to the present invention, according to the above-mentioned configuration, the trajectory which is normalized in advance, that is, the trajectory of the desired response waveform at the time of returning is set in several ways, for example, three kinds of speed, normal and slow speeds, and the driver gives the desired response. By selecting the waveform, that is, the target track, the difference between the target track vehicle speed given by this target track and the actual vehicle speed is used as the error vector, and the trajectory tracking type time delay control is used to control the operation amount of the throttle valve opening. By calculating, it is possible to control the actuator so that the convergence to the target vehicle speed will always match the trajectory of the desired response waveform without being affected by changes in the gear position and fluctuations in the running load. With good convergence, it is possible to perform constant speed running control that gives a desired response. Further, according to the present invention, a plurality of target trajectories having different normalized convergence times are set in advance by the above-mentioned configuration, and the target trajectories when the resume is turned on and the actual vehicle speed are detected according to the magnitude of the detected value. , By changing to the target trajectory with different convergence time, there is no discomfort for vehicle speed deviation,
It is possible to obtain a smooth response waveform. In addition, the initial control input characteristic best0 is set to the maximum value bM of the input distribution characteristic b of all target vehicle types.
AX, the constant-speed traveling control is performed by the target trajectory given by the function of time, and the target velocity using the average speed and position of the actuator and at least one of the deviation between the target vehicle speed and the actual vehicle speed or the differential value of the deviation. A target track vehicle speed is newly obtained by the track correction means. Then, by continuing the constant speed traveling control with the newly obtained target track vehicle speed, it is possible to obtain a reasonably smooth resume response suitable for each vehicle type. Further, when the control input characteristic best is significantly different from the input distribution characteristic b of the vehicle equipped with this constant speed traveling control device, at least one of the deviation or the differential value of the deviation and the average speed and position of the actuator are used. The control input coefficient best is modified by the control input coefficient determining means. Then, the control input is calculated by the control amount calculation means using the obtained control input characteristic, the convergence of the actual vehicle speed to the target vehicle speed is not affected by the change of the vehicle dynamic characteristics due to the change of the traveling load, It can be kept constant, stable, and can follow the target trajectory well. Also, by observing the changed state of the updated control input characteristic, the coefficient width correction means causes the initial control input characteristic best0 and the minimum control input characteristic best1 which are the maximum values of the control input characteristic.
And are updated, and the size of the allowable fluctuation range of the control input characteristic is updated. As a result, the initial control input characteristic best0 at the time of setting or resuming approaches the input distribution characteristic b of the vehicle type according to each running condition, and the initial control input amount best0 is used.
U (0) is calculated by the initial control input calculation means, and it is possible to reduce the drop in vehicle speed at the time of setting or resume ON,
It is possible to follow the target trajectory stably and satisfactorily.
Also, the return acceleration α that gives the target trajectory when the resume response converges is changed so that the differential value of the target vehicle speed V _d (t) becomes smaller, and the convergence acceleration is changed so that the target vehicle speed smoothly converges to the target vehicle speed. By the means, overshoot and undershoot at the time of convergence can be reduced. In addition, if the deviation between the target track vehicle speed and the actual vehicle speed exceeds a certain value due to the drop in vehicle speed when resume is turned on, the initial target trajectory changing means lowers the target track to the actual vehicle speed at that time, thereby unnecessarily increasing the accelerator. The vehicle constant-speed traveling control device can stably follow the target trajectory without jetting.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A vehicle will be described below as an automobile, and an embodiment of the present invention will be described with reference to the drawings.

First, the system configuration of the vehicle constant speed traveling control device and the configuration of the control system will be described. FIG. 1 is a block diagram conceptually showing a first embodiment of the present invention. The constant speed traveling command signal, the resume signal for returning to the same speed again after canceling the constant speed traveling command and performing the constant speed traveling, and the acceleration / deceleration signal for increasing / decreasing the vehicle speed during the constant speed traveling are input from the command circuit 11 to the constant speed traveling. When the command signal is input, the vehicle speed detection circuit 12 detects the actual vehicle speed, and the target value setting circuit 13 sets it as the target vehicle speed. The target trajectory setting means 15 gives a plurality of desired response waveform trajectories at the time of resume, and the target trajectory selecting means 19 selects one trajectory from the plurality of trajectories provided by the target trajectory setting means by the driver. From this target track vehicle speed, actual vehicle speed, and target vehicle speed,
The control amount calculation means 14 causes the actual vehicle speed to converge to the target vehicle speed with a desired response waveform, that is, the control input to the plant, that is, the control input to the actuator 16 so that the error between the actual vehicle speed and the target track vehicle speed becomes zero. Is calculated. That is, 14 and 15 are trajectory follow-up type time delay controls. Here, the control target, that is, the plant is the actuator 16+
The throttle valve 17 + the vehicle body 18. By the above operation, the opening of the throttle valve 17 is changed to the actuator 1
6, the vehicle speed converges to the target vehicle speed through the vehicle body 18 with the desired convergence, and constant speed traveling control that is stable at the target vehicle speed can be realized.

FIG. 2 is a block diagram conceptually showing one embodiment of the second invention of the present invention. When the target vehicle speed already set by the target value setting circuit 23 is restored by the resume operation of the command circuit 21 in the state where the constant speed traveling is once released, the actual vehicle speed at the start of the restoration is set to the vehicle speed detection circuit 22.
The return vehicle speed deviation detecting means 29 detects the deviation between the target vehicle speed and the actual vehicle speed, and the target trajectory setting means 25 gives a target trajectory having a different convergence time corresponding to the detected value. Thus, based on the target track vehicle speed, the actual vehicle speed, and the target vehicle speed given according to the magnitude of the initial deviation, the actual vehicle speed is a desired response waveform to the target vehicle speed, that is, the target track Plant (actuator 26 + throttle valve 27 + vehicle body 2
Calculate the control amount to 8).

FIG. 3 is a system configuration diagram of an embodiment of the present invention. In the figure, 38 is a CPU, ROM, RAM, I / O
It is a control circuit configured by, for example, and performs constant speed traveling control by input signals from various sensors and switches. 33 is
A switch for supplying power to the actuator power supply and the control circuit, 31 is a dual-purpose switch for setting a target vehicle speed and a coast switch for lowering the set value of the target vehicle speed, and 32 is a resume for returning to the target vehicle speed. It is a switch that also serves as an accelerator switch that increases the target vehicle speed setting. 35, when you press the brake
Brake switch that is turned on, 34 is a cancel switch that releases the set and resume functions, 3
A vehicle speed sensor 6 detects the actual vehicle speed. Numeral 37 is an N / P switch for detecting that the gear position is in the neutral or parking position, and numeral 39 is a solenoid for supplying or cutting off the power to the actuator 310 when starting or ending the constant speed traveling. Is. When the constant speed traveling control is started by turning on the set switch 31 or the resume switch 32, the solenoid 39 is turned on by the control circuit 38, and the difference between the actual vehicle speed of the vehicle speed sensor 36 and the set target vehicle speed is calculated. However, this value and R
The target track vehicle speed can be obtained from the information for generating the target track built in the OM, for example, the normalized target track data. Then, the control amount is calculated so that the error between the target track vehicle speed and the actual vehicle speed becomes zero, and the actuator 31
Output to 0. By driving the actuator 310, the throttle valve of 311 is opened / closed, and the fuel supply amount to the engine is adjusted, thereby realizing constant speed traveling control.

FIG. 4 is a control block diagram of the above embodiment. Based on this figure, a control concept of a trajectory tracking type time delay control (TDC) which is a type of adaptive control will be described. The actuator 45 adjusts the opening of the throttle valve 46 by the target opening input U, and the vehicle body 47
Control the vehicle speed through. The vehicle speed V is read by the vehicle speed sensor 43, and the actual vehicle speed when set by the target value setting circuit is set as the target vehicle speed Vset.
It is stored in the target vehicle speed setting 41. Resume switch 3
When 2 is turned on, the actual vehicle speed V at that time and the target vehicle speed Vse
From the difference from t, the target track setting means 42 gives the target track vehicle speed Vd as a function of time. This target track vehicle speed Vd is a desired response waveform at the time of convergence is given in time series, and the TDC control equation 44 controls the actuator 45 so that the deviation e between the actual vehicle speed V and the target track vehicle speed Vd becomes zero. The quantity U is calculated. At the time of setting, the target vehicle speed Vset becomes the target track vehicle speed Vd. By the above operation, the actual vehicle speed V
However, it is possible to perform speed control that follows the target vehicle speed Vset with a desired response characteristic, that is, follow the target track vehicle speed Vd, and constant speed traveling control that is always stable and has a constant convergence can be realized. Next, the design of the control system of this trajectory tracking type time delay control (hereinafter TDC) will be described.

First, the transfer function of the plant is obtained. When the target opening input to the actuator 45 is U (S) and the actual vehicle speed is its output V (S), the transfer function G (S) during this period is given by the following equation. G (S) = b / (S + a) (1) Although the controlled object was approximated by the first-order delay in this way, in reality, the parameter varies depending on the running state, and it is also a nonlinear plant including dead time. This TDC is a controller effective for a system having unknown dynamic characteristics, and hereinafter, for a non-linear plant, a trajectory tracking type control law suitable for CP operation is obtained. Regarding this, Osamu Ito et al., "Proposal of Time-Delay Control for Tracking Tracking and Its Application to Robot Manipulator Control", Journal of Precision Engineering 55/1
Details are given in 2/1989 etc.

First, the equation (1) is converted into the time domain as follows. However, the differentiation is represented by d / dt. dV (t) / dt = -aV (t) + bU (t) (2) It is assumed that a and b are unknown and the fluctuation range is known as follows. 0 <amin <a <amax (3) 0 <bmin <b <bmax (4) Here, the target track vehicle speed of the vehicle speed V is defined as Vd, and this deviation is defined as e. e = Vd-V (5) From the equations (2) and (5), the following equation that governs the dynamic characteristic of the error is obtained. de (t) / dt = dVd (t) / dt + aV (t) -bU (t) (6) Here, if U can be determined so as to always satisfy the following equation, dVd (t) / dt + aV (t) -bU (t) =-Ae · e (t) (7) From the equations (6) and (7), the following equation is obtained. de (t) / dt = -Ae · e (t) Ae> 0 (8) Therefore, any error dynamic characteristic can be defined by Ae.
When the control input U is obtained from the equation (7), the following equation is obtained. U = b ⁻¹ (dVd / dt + aV + Ae · e) (9) However, the unknown variables a and b are included in the above equation, and the control input U cannot be determined as it is. Therefore, consider estimating this unknown part.

First, the equation (2) is divided into an unknown part aV and other parts as follows. aV = -dV / dt + bU (10) Here, assuming that L is a minute time delay and aV = h, the following is assumed.

From the equations h (t) m ² h (tL) (11) (10) and (11), the unknown term aV, that is, h is estimated by the following equation. hest (t) =-dV (tL) / dt + bU (tL) (12) Substituting this estimated value hest into equation (9), the control law of the time delay control for constant speed traveling control is Given in. U (t) = U (tL) + b ⁻¹ {-dV (tL) / dt + dVd (t) / dt + Ae · e} (13) However, the equation (13) for calculating the control input U is Since the unknown term b is included, the control input U (t) to the actuator cannot be determined as it is. Then, the control system substitutes the estimated value best of b into the equation (14) so that the control system becomes stable, and the actual control input is obtained. That is, the control input is given by the following equation. U (t) = U (tL) + best ^-1 {-dV (tL) / dt + dVd (t) / dt + Ae · e} best> 0 (14) A detailed block diagram is shown in FIG. A control input U to the controlled object 53
Is given, the vehicle speed V is output. Target track vehicle speed V
The deviation between d and V is set to e, the error convergence is guaranteed by the target error characteristic insertion unit 51 by this Vd and e, and the nonlinear term is estimated by the unknown characteristic canceling unit 52 by the actual vehicle speed V and U, to obtain the locus. The follow-up type time delay controller 54 is configured to calculate the control input U to the controlled object 53 so that the deviation e becomes zero and the desired response waveform is obtained. That is, -dV (tL) / dt and U (tL) are unknown part cancellation terms of the plant, and dVd (t) / dt + Ae · e is an error dynamic characteristic insertion term for an arbitrary target trajectory.

Next, the derivation of the estimated value best so that the entire control system becomes stable will be described. First, Laplace transform of equation (14) gives the following equation. best (1-e- ^LS ) U (S) = {-(Se- ^LS + Ae) V (S) + (S + Ae) Vd (S)} (15) Also, the formula (2) is also Laplace Convert. U (S) = b ⁻¹ (S + a) V (S) (16) From the equations (15) and (16), the following equation is obtained. {bestb ^-1 (S + a) (1-e ^-LS ) + Se ^-LS + Ae} V (S) = (S + Ae) Vd (S) (17) where the Paddy approximation is expressed by (17) Used for. That is, the following equation is substituted. e ^-LS = (2-LS) / (2 + LS) (18) V (S) / Vd (S) = (2 + LS) (S + Ae) / (2bestb ^-1 (S + a) LS + S (2-LS) + (2 + LS) Ae} (19) Therefore, the condition for the above equation to be stable is obtained by Rouse's stability determination. First, let F (S) be the denominator of Eq. (19), and arrange for S. F (S) = (2bestb ^-1 -1) LS ² + {(2aestb ^-1 + Ae) L + 2} S + 2Ae (20) = A ₀ S ² + A ₁ S + A ₂ where (3 ) (4) From the parameter ranges of Eqs. (8) and (14), it can be seen that A ₁ and A ₂ are positive, so the following equation is a necessary and sufficient condition for stability. A ₀ = (2bestb ^-1 -1) L> 0 (21) Therefore, the condition for best is given by the following equation. best> b / 2 (22) Therefore, the best must be 1/2 or more of the true value. Therefore, considering the parameter range of equation (4), equation (22) becomes the following equation. best> bmax / 2 (23) Based on the above, this estimated value and the control input obtained from Eq. (14)
By using U, it is possible to obtain a response that satisfies the error dynamic characteristics of Eq. (8). Although the control input is calculated by approximating the controlled object by the first-order delay, it may be designed as a second-order or higher plant.

Next, a method of calculating the target track vehicle speed Vd will be described. FIG. 6 is a diagram of a target trajectory normalized by both the vehicle speed axis (vertical axis) and the time axis (horizontal axis) given by the target trajectory setting means of the first embodiment. For example, the driver's preference is given in three ways as shown in (A), (B), and (C), (A) is speedy, (B) is normal, and (C) is slow. It is the orbit. For example, if the driver is a young person and wants to return to the vehicle with a very responsive acceleration, he or she may select (A) by the target trajectory selecting means. Also, if the driver is old and wants to return home with slow responsiveness, the target trajectory selection means (C)
Should be selected. In this way, the normalized target trajectory of any one of (A), (B), and (C) is selected, and the initial vehicle speed, which is the absolute value of the deviation between the target vehicle speed Vset and the actual vehicle speed when the resume is turned on, is selected. By multiplying the deviation, the target track vehicle speed at the time of convergence to the target vehicle speed is calculated.

FIG. 7A shows a vehicle speed axis (vertical axis) having different convergence times given by the target trajectory setting means of the second embodiment.
Only a normalized target trajectory diagram. For example, if the vehicle speed range in which constant speed running is possible is 50 km / h to 100 km / h, the initial vehicle speed deviation when the resume is ON is 0 to
It is 50 km / h, and as an example, it is divided into three target trajectories with different convergence times as follows. 0-15km / h
(A), 15 to 35 km / h (B), 35 to 50 km
/ H is (C), and the convergence time to each target vehicle speed is, for example, 10 seconds, 20 seconds, and 30 seconds. FIG. 7B shows the tracks (D) and (E) of the target track vehicle speed when the vehicle speed deviation during resume is 10 km / h and 25 km / h, respectively. For example, when the deviation between the target vehicle speed and the actual vehicle speed when the resume switch is turned on, that is, the initial vehicle speed deviation FE is 25 km / h, first, the normalized target trajectory of (B) in FIG. 7A is selected.
Next, on this normalized target track, the initial vehicle speed deviation of 25k
The value multiplied by m / h is shown in (E) of FIG. 7 (b), and the vehicle speed obtained by adding the actual vehicle speed at the time of resume ON as a bias is the target track vehicle speed at the time of return and is given at each control cycle. Be done.

FIG. 8 is a control block diagram of an embodiment of the invention described above. Based on this figure, a method of calculating the target track vehicle speed Vd and a control concept of a track-following time delay control (hereinafter TDC) which is a kind of adaptive control will be described. First, the calculation of the target track vehicle speed will be described.
The target trajectory selecting means 85 selects a desired target trajectory shape from the normalized trajectories given by the target trajectory setting means 84. Next, with respect to this normalized target trajectory, the return vehicle speed deviation detecting means 82 uses the target vehicle speed Vset set by the target value setting circuit 81 and the actual vehicle speed at the time of resume ON obtained by the return vehicle speed detection 83 by the return vehicle speed deviation detecting means 82. The initial vehicle speed deviation FE is calculated, and the target trajectory setting means 84 changes the time axis of the preselected normalized target trajectory, that is, the convergence time according to the magnitude of the detected value FE. Then, the control amount calculation means 86 multiplies the target trajectory by the initial vehicle speed deviation FE, and the resume vehicle speed detection 83 causes the resume to be turned on.
The target track vehicle speed Vd is calculated by adding the actual vehicle speed at that time as an offset amount. And TDC control type 8
7, the deviation e between the target track vehicle speed Vd and the actual vehicle speed V detected by the vehicle speed detection circuit 89 is set to zero, that is, the actual vehicle speed V converges to the target vehicle speed with a desired response waveform given by the target track vehicle speed Vd. A manipulated variable U for the plant is calculated. Here, the plant is (actuator + throttle valve + vehicle body) 88. Figures 22 to 27 are 2000cc
Track-following time for turbo cars (205/6400 (PS / rpm))
These are the results of a test run on the chassis with the delay control. The control input is given by the following equation which is a discretization of equation (14).

U (k) = U (k-1) + best ^-1 {-(V (k) -V (k-1)) / L + (Vd (k) -Vd (k-1)) / L + Ae ・ e (k)} (24) Vd (k) = (1-cos (π * k / TAU)) * (Vset-V0) / 2 (25) best = 0.11808, Ae = 0.11574, Control cycle L = 720msec Vset is the target vehicle speed, and V0 is the actual vehicle speed when the resume switch is on. When TAU = 20, the settling time is 20 seconds, and when TAU = 30, it is 30 seconds. 22 to 27 are all resume operations at vehicle speeds of 50 km / h to 80 km / h. 22 to 24 show the results of the resume experiment at + 3%, 0%, and -3% when the target track vehicle speed with settling time of 30 seconds was given. 25 to 27 show the results of the resume experiment at + 3%, 0%, and -3% when the target track vehicle speed with the settling time of 20 seconds was given. By selecting the target trajectory in this way, the desired response waveform can be obtained. In addition, the control system is extremely robust against changes in gradient.

Next, the target trajectory automatic correction method and the control gain automatic change rule will be described. FIG. 9 is a block diagram conceptually showing the third embodiment of the present invention. Vehicle speed detection circuit 91
The actual vehicle speed of the vehicle body 97 is read by the target value setting circuit 9
According to 2, the actual vehicle speed when set is set as the target vehicle speed. Then, the target track setting means 93 calculates a target track vehicle speed that gives a reference track at which the actual vehicle speed converges to the target vehicle speed with a desired response waveform. Then, the control amount calculation means 95 calculates the control amount to the actuator 96 based on the deviation so that the deviation between the actual vehicle speed and the target track vehicle speed becomes zero. Also, the target trajectory setting means 9
The target track vehicle speed given by 3 is the actuator 9
Based on the output value of 6 and the deviation, the target track correction means 94 corrects the target track vehicle speed suitable for each vehicle type and running state. Then, using the newly corrected target track vehicle speed, the control amount calculation means 95 continues to perform constant speed traveling control.

Next, a basic concept for correcting the target track vehicle speed V _d (t) will be described. The target trajectory setting means 9
From 3, the target track vehicle speed V _d (t) is calculated. this is,
It is given as a function of time, for example, it has a map that gives a normalized target trajectory, and by multiplying this map by the difference between the target vehicle speed at the time of resume and the actual vehicle speed, the target track vehicle speed for each control cycle is Given as a time series. Further, the target track vehicle speed may be calculated by giving the acceleration at the time of convergence. When performing control to follow this target track vehicle speed V _d (t), there are some vehicles that can follow depending on the vehicle installed and due to differences in running conditions such as road gradients, and others that cannot follow at full throttle. To do. Therefore, it is necessary to correct the target track vehicle speed to a target track vehicle speed that can follow the vehicle that cannot follow.
Therefore, FIG. 10 shows a basic flow for examining the tracking possibility and correcting the target trajectory. In the following description, a controlled object represented by the following one-input one-output first-order lag system will be considered. G (s) = V (s) / U (s) = b / (s + a) (26) where s: Laplace operator, V: vehicle speed, U: input, a: unknown characteristic, b: unknown This is an input distribution characteristic. In Figure 10, e
(t) is the deviation between the target track vehicle speed V _d (t) and the actual vehicle speed V (t), e (t) = V
_d (t) -V (t), and de (t) / dt (= Δe (t)) is the differential value of the deviation. U (t) is the target deviation characteristic de (t) / dt = -k ・ e (t) (k
Is a control input that satisfies the deviation feedback coefficient) and is calculated by the following equation. U (t) = U (tL) + {-dV (tL) / dt + dV _d (t) / dt + k ・ e (t)} / best (27) where L is an arbitrary small time delay, U (tL) is the input applied to the controlled object before time L, dV (tL) / dt is the differential value of the actual vehicle speed detected from the controlled object before time L, and best is the control input characteristic. Further, ΔU is ΔU = dU (t) / dt, which is a differential value of U (t). After resuming in step 101, step 1
In 02, the deviation e is compared with the set value f1> 0, and if larger, it is determined in step 103 whether the differential value Δe of the deviation is positive. Then, if Δe is positive, the control input U and g1> 0 are compared in step 104. For example, the saturation value of the control input is used as the value of g1. Where e> f1 and Δe> 0
If U ≧ g1, the target trajectory is corrected in step 110.
On the other hand, if U ≧ g1 is not satisfied, the change amount ΔU of the control input U is compared with g2> 0 in step 105. For example, the value of g2 is the maximum velocity value in the opening direction of the actuator. At this time, e>
If f1 and Δe> 0 and ΔU ≧ g2, the target trajectory is corrected in step 110. Further, in step 102, the deviation e is the set value f1>
If it is smaller than 0, the deviation e is f3 <0 in step 106.
If it is smaller, it is judged in step 107 whether the differential value Δe of the deviation is positive. Then, if Δe is negative, the control input U and g3> 0 are compared in step 108. For example, the minimum value of the control input is used as the value of g3. If e <f3 and Δe <0 and U ≦ g3, step 11
Go to 0 and correct the target trajectory. If U ≦ g3 is not satisfied, then in step 109, the variation amount ΔU of the control input U is compared with g4 <0. For example, the value of g4 is the maximum speed value in the closing direction of the actuator. At this time, when e <f3 and Δe <0, ΔU ≦ g4
Then, in step 110, the target trajectory is corrected. The rules for correcting the target trajectory are summarized below. [1] IF e> f1, Δe> 0, U ≧ g1 THEN Correct the target trajectory. [2] IF e> f1, Δe> 0, ΔU ≧ g2 THEN Modify the target trajectory. [3] IF e <f3, Δe <0, U ≦ g3 THEN Correct the target trajectory. [4] IF e <f3, Δe <0, ΔU ≦ g4 THEN Correct the target trajectory. [5] Do not modify anything other than the above. Alternatively, the determination may be made by comparing only the deviation e, and when the control target is a high-order delay system, it is also possible to use the higher-order differential value of the deviation. Also, although zero was used for the comparison value of Δe,
A dead zone may be provided such that the deviation e is f3 <e <f1. Next, one method of correcting the target trajectory in step 110 will be described with reference to FIG. In the figure, (A) shows the target trajectory setting means 93.
By a target trajectory vehicle speed V _d given represent the actual vehicle speed V from when ON the resume is (C). If the target track vehicle speed V _d as it is is used, overshoot may occur and the settling time may become long as indicated by the dotted line in (C). Therefore, when the conditions for performing the target track correction are met in the flow of FIG. 10, for example, the target track vehicle speed (A) is shifted so as to match the speed at the time when the conditions are met, as shown in FIG. By setting a new target track vehicle speed, it is possible to prevent excessive acceleration and obtain smooth acceleration without overshoot. still,
As a new target track vehicle speed determination method, the track (A) is extended with respect to the time axis so as to match the speed V at the time when the conditions are aligned as shown in (D) in the figure, and a new target track vehicle speed is also set. good. Alternatively, the trajectory may be given by a trigonometric function and the period thereof may be lengthened. Furthermore, if the input and output variables of the above rules [1] to [5] are given by fuzzy variables, and if the target trajectory is a trigonometric function, the consequent output variable is its period,
The target trajectory may be determined by obtaining the period by the direct method and the indirect method.

Next, an embodiment of the present invention will be described with reference to the drawings for how to provide an optimum target trajectory in cruise control.

In the following, the target track setting means calculates the target track vehicle speed that gives the reference track at which the actual vehicle speed converges to the target vehicle speed at the desired return acceleration α during resume. This target track vehicle speed Vd (t) is given in advance by giving the inclination of the target track at the time of convergence, that is, the return acceleration α, and adding the increase amount of this return acceleration α to the vehicle speed at the time of resume on every control cycle. .. When performing control to follow the target track vehicle speed Vd (t), there are some vehicles that can follow and some vehicles that cannot follow at full throttle depending on the mounted vehicles. So, for a car that can't follow like this,
It is necessary to correct the target track vehicle speed so that the target track vehicle speed can be followed.

FIG. 12 is a block diagram conceptually showing the fourth embodiment of the present invention. The actual vehicle speed of the vehicle body 127 is detected by the vehicle speed detection circuit 121, and the actual vehicle speed at the time of setting is set as the target vehicle speed by the target value setting circuit 122. Then, the target track setting means 123 calculates a target track vehicle speed that gives a reference track that converges the actual vehicle speed to the target vehicle speed with a desired response characteristic at the time of resume, for example, at a constant acceleration α at the time of return. Then, the control amount calculation means 12 is set so that the deviation between the actual vehicle speed and the target track vehicle speed becomes zero.
5, the control amount for the actuator 126 is calculated based on the deviation. Also, the convergence acceleration changing means 124
When the difference between the target track vehicle speed and the target vehicle speed becomes less than a certain value, the target track vehicle speed at the end of the resume is smoothed by changing the acceleration when converging to the target vehicle speed to a small value. Will be corrected to. Then, by using the newly corrected target track vehicle speed to continue the resume control by the control amount calculating means 125, a resume response without overshoot can be performed at the time of convergence.

Next, the basic concept of changing the acceleration α when the target track vehicle speed converges to the target vehicle speed will be described. The target track vehicle speed is set by the target track setting means 123.
Vd (t) is calculated. This is given by previously giving the inclination of the target trajectory at the time of convergence, that is, the return acceleration α, and adding the increase amount of the return acceleration α to the vehicle speed at the time of resume ON for each control cycle. When the deviation between the target track vehicle speed Vd (t) and the target vehicle speed becomes a certain value or less, the cycle of the target track vehicle speed calculation is shortened, and the acceleration α is reduced at a certain rate. , The amount of change when the target track vehicle speed converges to the target vehicle speed becomes small, the discontinuity due to the sudden change of the target track disappears, and it is possible to suppress overshoot and undershoot when the resume response converges, and it feels uncomfortable during resume. It is possible to realize a constant speed traveling control device that does not have a constant speed. It should be noted that the calculation cycle of the target track vehicle speed at the time of convergence may be constant, and the method of decreasing the acceleration α is not a constant rate. For example, the rate of decrease is large when the deviation is large and is decreased as the convergence approaches. Such a method may be used. Next, FIG. 13 is a configuration diagram conceptually showing a fifth embodiment of the present invention. The vehicle speed detection circuit 131 detects the actual vehicle speed of the vehicle body 137, and the target value setting circuit 132
Thus, the actual vehicle speed at the time of setting is set as the target vehicle speed. Then, the target track setting means 133 calculates a target track vehicle speed that provides a reference track at which the actual vehicle speed converges to the target vehicle speed at the desired return acceleration α during resume. Then, the control amount calculation means 135 calculates the control amount to the actuator 136 based on the deviation so that the deviation between the actual vehicle speed and the target track vehicle speed becomes zero. Further, when the resume is turned on, the target track vehicle speed given by the target track setting means 133 is changed to the value of the actual vehicle speed at the time when the initial target track changing means 134 makes the deviation above a certain value. Then, by using the newly changed target track vehicle speed, the control amount calculating means 135 continues the resume control, whereby the influence of the dead time due to the slack of the throttle wire and the like can be eliminated, which is wasteful. Smooth resume response control can be performed without accelerating.

Next, the basic concept of changing the target trajectory when the resume is turned on will be described with reference to FIG. First, (B) in the figure represented by the thin broken line represents the target trajectory to the target vehicle speed after resume ON when the initial target trajectory is not changed, and the vehicle speed response when using this target trajectory vehicle speed is thick. It is shown by (D) in the figure represented by a broken line. The control input at this time is represented by (F) in the figure. If the track is not changed in this way, the track is tried to catch up with the track, resulting in an excessive throttle opening amount, which causes an overshoot as shown in (D) in the figure. In addition, the sudden acceleration makes the driver feel uneasy and makes the ride uncomfortable. Therefore, if the actual vehicle speed deviates from the target trajectory vehicle speed by a certain value or more after the resume is turned on by the initial target trajectory change means, the target trajectory is reduced to the actual vehicle speed at that time as shown in (A) in the figure. The vehicle speed accurately follows as shown in (C) in the figure, and the control input amount also has a reasonably smooth response waveform as shown in (E) in the figure.

28 and 29 show the results of the actual vehicle test in each means for changing the target track. The control formula is given by formula (24), and L = 720 msec, best = 0.11808, Ae = 0.11574. In addition, the target track vehicle speed Vd is the slope α at the time of restoration (at the time of resume).
Vd = V0 + α * L (27) However, α = 1.5km / h / sec or 1.0km / h / sec In both figures, the target trajectory was given by the acceleration which shows the inclination at the time of return. The test car in Fig. 28 is a 2000cc non-turbo car (125/5600
(PS / rpm)), road gradient is 0%, vehicle speed range is 50km / h ~ 100km
This is a chassis experiment in the resume operation of / h. Canceled while running at 100 km / h, decelerated with the throttle opening fully closed, and when the vehicle speed reached 50 km / h,
It is the figure which turned on the resume switch. As can be seen from the figure, after the resume switch is turned on, the target track vehicle speed is given with a certain inclination, but the actual vehicle speed is still decreasing, and the vehicle speed deviation increases. Therefore, by making the target value coincide with the actual vehicle speed by the initial target trajectory changing means, reasonable acceleration can be obtained and abnormal opening of the throttle opening is eliminated. Further, the convergent acceleration changing means smoothly converges to the target vehicle speed without overshooting.

FIG. 29 shows the same experimental vehicle as + 3%, 70 km / h to 10
It is an experimental result of performing a resume operation at 0 km / h. Figure 2
Similar to 8, the target trajectory is changed after the resume switch is turned on, and the vehicle speed deviation increases again even though the target trajectory is matched with the actual vehicle speed. Therefore, by the target trajectory correcting means,
It is determined that it is impossible to follow the acceleration given the target trajectory, and the acceleration is changed. This makes it possible to obtain a comfortable resume response.

Next, the control gain automatic change rule will be described. FIG. 15 is a block diagram conceptually showing the sixth embodiment of the present invention. The vehicle speed detection circuit 151 allows the vehicle body 157.
The actual vehicle speed is read and the target value setting circuit 152 sets the actual vehicle speed when set as the target vehicle speed. Then, the target track setting means 153 calculates a target track vehicle speed that gives a reference track at which the actual vehicle speed converges to the target vehicle speed with a desired response waveform. Then, the control amount calculation means 155 calculates the control amount to the actuator 156 based on the deviation so that the deviation between the actual vehicle speed and the target track vehicle speed becomes zero. Further, the control input characteristic best in the control amount calculation means 155 is changed to the control input characteristic according to each traveling state by the control input coefficient determination means 154 based on the output value of the actuator 156 and the deviation. Then, using the newly calculated control input characteristic best, the control amount calculation means 155 continues to perform constant speed traveling control. Next, when the control input characteristic best and the actual input distribution characteristic b of the controlled object are different, the basic idea of changing the control input characteristic best for making the actual vehicle speed follow the target track vehicle speed well is as follows. explain. First, the controller input characteristic (control input characteristic) best is larger than the actual input distribution characteristic b in order to create a rule that determines the control input characteristic best using the deviation, the differential value of the deviation, and the position / velocity of the actuator. In the case, the target track vehicle speed Vd and the vehicle speed V which is the output of the controlled object are shown in the upper diagram of FIG. 16, and the input to the actuator is shown in the lower diagram of FIG. In the figure, Ue is
Indicates the input when best = b (however, b> 0). As shown in the upper diagram of FIG. 16, four states (A) to (D) are possible. Therefore, how to change the best in each state will be described with reference to the flows of FIGS. 17 and 18. First, resume is started in step 171, and best is set to b _MAX in step 172. Then, it is first determined in steps 173-177 whether or not the oscillator is oscillating,
If it is oscillating, the control input characteristic best is increased and the system pole is moved in a stable direction to suppress the vibration. Specifically, first, in step 173, it is determined whether the product of the differential values (which may be the differential value of the deviation) of the two inputs that are L times apart is significantly negative. As a control input characteristic in step 174 for stabilization
Increase best. Next, in step 175, the absolute value of the deviation is compared with a certain value FA, and if it is small, that is, in the constant speed traveling state, it is judged in step 176 whether or not the vibration is small. Control input characteristics
Increase best. If it is determined in the above oscillation determination that the vibration is not occurring, it is determined in step 178 whether the absolute value of the deviation is larger than a certain set value FB.
At 712, the control input characteristic best is reduced, and step 171 is performed.
Change to the target trajectory according to the ability of the car by 4. Next, when the state is (A) of FIG. 16, that is, step 179.
It is determined that the deviation is larger than f1> 0, and step 17
When it is determined by 10 that the differential value of the deviation is larger than the set value f2 = 0, the step 17
Judgment according to 11,1713, steps 1714,171
The best and target trajectories are changed according to 5. The state of (A) means that the input characteristic best of the controller is larger than the actual input distribution characteristic b, as in [a-1] Uphill, and therefore the increase in the input of the controller is small and sufficient. Input is not obtained. [a-2] Even if the actuator is at the maximum displacement position (full throttle), the vehicle speed will not increase due to the engine capacity. [a-3] The desired input cannot be obtained due to actuator delay. The above rules are as follows. [a-1] IF e (t)> f1, Δe (t)> f2, U (t) ≦ g1, ΔU (t) ≦ g2 THEN
reduce the best. [a-2] IF e (t)> f1, Δe (t)> f2, U (t) ≧ g1 THEN Change the target trajectory. [a-3] IF e (t)> f1, Δe (t)> f2, U (t) ≦ g1, ΔU (t) ≧ g2 THEN
Change the target trajectory.

Similarly, in the state (B) of FIG. 16, it is determined that the deviation is larger than f1> 0 in step 179, and the differential value of the deviation is smaller than the set value f2 = 0, that is, negative in step 1710. It is a state determined to be present, and the following states are possible. [b-1] best> b and the input is increased by reducing the best in the part (A), but since it is still the best> b, the input cannot be sufficiently reduced. The deviation decreases more than the target deviation characteristic. [b-2] The actual input distribution characteristic b has increased more than the input characteristic currently used by the controller, such as a downhill slope. [b-3] Do not change except the above. The above determination is made in steps 1716, 1717, 1719, and the best is changed in steps 1718, 1720. The above relationship is converted into rules as follows. [b-1] IF e (t)> f1, Δe (t) <f2, e decreases beyond the target deviation characteristic, and U (t) ≧ g3, ΔU (t) ≧ g4THENbest is decreased. [b-2] IF e (t)> f1, Δe (t) <f2, e decreases beyond the target deviation characteristic, and U (t) ≦ g3 THEN best increases. [b-3] IF e (t)> f1, Δe (t) <f2, other than above Do not change THEN best. Similarly in the state (C) of FIG. 16, the same thing can be said, and in the state (C), the deviation is the set value in step 1721.
It is determined that it is smaller than f3 <0, that is, smaller than a certain negative value, and that the differential value of the deviation is smaller than the set value f2> 0, that is, negative in step 1723. c-1] best> b and the input was increased by decreasing the best in the part (B) to catch up with the target trajectory, but since it is still best> b, a sufficient decrease in the input cannot be obtained. [c-2] A state in which the actual input distribution characteristic b has increased more than the input characteristic currently used by the controller, such as a downhill slope. [c-3] Do not change except the above. 18 and in step 1724 in FIG.
In 1726, it is determined which state (C) is, and in steps 1725 and 1727, the target trajectory and best are changed. The above (C) states are converted into rules as follows. [c-1] IF e (t) <f3, Δe (t) <f2, U (t) ≧ g3, ΔU (t) ≧ g4 THEN
reduce the best. [c-2] IF e (t) <f3, Δe (t) <f2, U (t) ≦ g3 THEN Change target trajectory. [c-3] IF e (t) <f3, Δe (t) <f2, U (t) ≧ g3, ΔU (t) ≦ g4 THEN
Change the target trajectory. Similarly, with respect to the state (D) in FIG. 16, it is determined in step 1721 that the deviation is smaller than the set value f3 <0, that is, smaller than a certain negative value, and the differential value of the deviation is set value f2 in step 1723. It is a state judged to be larger than> 0, that is, positive, and [d-1] is still best> b, and a sufficient reduction of the input cannot be obtained, and the deviation decreases more than the target deviation characteristic. [d-2] A state in which the actual input distribution characteristic b is decreasing, like an uphill slope. [d-3] Do not change except the above. Then, in steps 1728, 1729, 1730, it is determined which state is present, and in steps 1731, 1732, b
Change est. The above (D) state is converted into a rule as follows. [d-1] IF e (t) <f3, Δe (t)> f2, e decreases beyond the target deviation characteristic, and U (t) ≦ g1, ΔU (t) ≦ g2 THEN best is decreased. [d-2] IF e (t) <f3, Δe (t)> f2, e decreases beyond the target deviation characteristic, and U (t) ≧ g1 THEN best decreases. [d-3] IF e (t) <f3, Δe (t)> f2, other than the above THEN best remains unchanged. Here, it can be determined by the following equation whether the deviation is reduced more than the target deviation characteristic. ｜ (1-exp (-k ・ L)) ・ e (tL) ｜ <｜ e (tL) -e (t) ｜ (26) In the above rules [a-1] to [d-3], When the controlled object is a high-order lag system, it is possible to create a rule using a higher-order differential value of the deviation, and the best may be changed by using various rules according to the controlled object. Furthermore, FIGS.
In the above, change the best part of the above rule to best = best * zo
u (zou> 1.0), best = best * gen (gen <1.0), but the coefficient zo
The method of giving u and gen may be simply a numerical value or the following expression. zou = 1 + ｜ e ｜ ・ uk gen = 1- ｜ e ｜ ・ uk (uk> 0) (27) Also, the input / output variables in the rule are expressed by fuzzy variables,
Best may be estimated by the direct method or the indirect method.

As described above, according to the present embodiment, the initial control input characteristic best is set to the maximum value b _MAX of the input distribution characteristic b of all target vehicle types, and the vehicle is driven at a constant speed by the target trajectory which is normalized and given in advance in the map. By controlling, at least one of the deviation or the higher derivative value of the deviation and the average speed and position of the actuator are used to set an appropriate target track vehicle speed according to the capability of the vehicle type newly installed by the target track correction means. You can ask. Further, when the initial control input characteristic best is significantly different from the input distribution characteristic of the vehicle equipped with this constant speed traveling control device, at least one of the deviation or the higher derivative of the deviation and the average speed and position of the actuator are set. By using the control input coefficient determining means to change the control input characteristic, and using the control input characteristic best to calculate the control input by the control amount calculating means, the convergence of the actual vehicle speed to the target vehicle speed is calculated. It can be kept constant without being affected by changes in vehicle dynamic characteristics due to load fluctuations, etc., and can stably follow the target trajectory well.

It should be noted that the same effect can be obtained for the controlled object of the one-input one-output high-order delay system. Further, the control amount calculation means may be configured by a digital circuit system. In this case, a constant speed traveling control device can be easily realized by setting the sampling cycle to a time delay L or setting an integral multiple of the sampling cycle to L Can have the same effect. Further, when the differential value of the vehicle speed cannot be directly detected, the differential value of the vehicle speed may be obtained.

Next, an embodiment of the present invention will be described with reference to the drawings with respect to a method of narrowing the fluctuation range of best and calculating the optimum initial control input amount for each vehicle.

First, the system configuration and control system configuration will be described. FIG. 19 is a block diagram conceptually showing the seventh embodiment of the present invention. The actual vehicle speed of the vehicle body 189 is read by the vehicle speed detection circuit 181, and the target value setting circuit 182 is read.
Thus, the actual vehicle speed when set is set as the target vehicle speed. Then, the target track setting means 183 calculates a target track vehicle speed at which the actual vehicle speed has a desired response characteristic to the target vehicle speed, that is, a reference track that converges at a constant acceleration α at the time of return. When set, the target vehicle speed becomes the target track vehicle speed. Then, the control amount calculation means 187 calculates the control amount to the actuator 188 based on the deviation so that the deviation between the actual vehicle speed and the target track vehicle speed becomes zero.
Further, the control input characteristic best in the control amount calculation means 187
Is changed to a control input characteristic suitable for each traveling state by the control input coefficient determining means 184 based on the output value of the actuator 188 and the deviation. Then, by using the newly calculated control input characteristic best, the control amount calculating means 18
7, the constant speed traveling control is continuously performed. here,
The newly calculated change state of the control input characteristic best is observed by the coefficient width correction means 185, and the value of the next initial control input characteristic best0, that is, the upper limit value of the fluctuation width of the control input characteristic best and the minimum control input characteristic best1. Value, that is, the lower limit value of the fluctuation width of the control input characteristic is determined. Using the best0, the initial control input calculating means 186 calculates the initial control input amount U (0) at the time of setting or resuming, and gives the initial target throttle opening degree according to the type of vehicle to be mounted and the road surface condition during traveling. You can Next, a basic concept for determining the variation range of the control input characteristic best for each vehicle type, that is, the upper limit value and the lower limit value will be described below. First, during constant speed traveling, the control input characteristic best is updated by the control input coefficient determining means according to the traveling state. Here, the initial value of the control input characteristic best at the first cruise start after mounting, that is, the upper limit value of the fluctuation range best0
Since it is not known which vehicle model is installed, is set to the maximum value b _MAX of the input distribution characteristic b of all target vehicle models in order to compensate for stability. 20 and 21 show a basic flow for updating the upper limit value best0 and the lower limit value best1 by the coefficient width correction means. In step 191, the cruise is turned on and the constant speed traveling control is started. At this time, in step 192, the upper limit value and the lower limit value of the control input characteristic are set to b _MAX and b _MIN , respectively. In steps 193 to 1914 below, the upper limit value best0
Is updated, and the lower limit is set in steps 1915 to 1933.
Update best1. During this period, best is constantly updated by the control input coefficient determination means. First, in step 193, it is determined whether or not the vehicle is traveling at a constant speed, that is, whether the absolute value of the deviation is smaller than a certain value A.
Go to and determine if the control input is oscillating.
If it does not oscillate, it is judged in step 195 whether or not it oscillated in the past. If it does not oscillate, when the stable constant-speed running state exceeds a certain set time T1, that is, the count value ta is Step 1 when T1 or more
Proceed to 97, clear ta, and set the upper limit value be in step 198.
Decrease st0 by a certain value gen. Then, in steps 199 and 1910, the fluctuation range of the control input characteristic best is set to be a certain value H or more. Also, step 19
If the control input is oscillating in step 4, step 19
In step 11, the upper limit value best0 is increased by a certain fixed value zou, and in steps 1912 and 1913, it is set so as not to exceed b _MAX . Then, in step 1914, the oscillation determination flag is set, and in step 195, it is prevented from becoming smaller than best0. Next, the lower limit value be
I will explain about the update of st1. In step 1915, the updated control input characteristic best is the best before the last time.
Is smaller than the minimum value bm, the counter tb is reset in step 1916, and the minimum value bm is updated in step 1917. In step 1918, it is determined whether or not the best this time is the same as the minimum value bm, and if it is the same, in step 1919, it is determined by the value of the counter tb whether or not this state has passed a certain time T2 or more, If it has elapsed, the counter tb is reset in step 1920, and it is determined in step 1921 whether this minimum value bm is the current lower limit value best1. If they are the same, the count tc is reset in step 1922, and in step 1923. The lower limit value best1 is reduced by a certain fixed value gen. Then, by steps 1924 and 1925,
_Make sure that the updated lower limit value does not _fall below b _MIN . If they are not equal in step 1921, the process proceeds to step 1927. If they are not equal in step 1918, the process proceeds to step 1926, the counter tb is reset, and in step 1927, the minimum value bm of best is the lower limit value best1.
The counter tc determines whether or not the larger state has passed a certain time T3 or more, and if it has passed, step 192
The counter tc is reset at 8 and the lower limit value best1 is increased by a certain fixed value zou at step 1929. Then, in steps 1930 and 1931, there is a certain range of upper and lower limits.
Keep H, steps 1932, 1933
Make sure that the lower limit value updated by does not exceed the minimum value bm of best. By the above operation, the upper limit value best0 and the lower limit value best1 are set to the maximum value of the set fluctuation range, the minimum value b _MAX , which is within the range of b _MIN , and the constant width H or more, while being mounted vehicle type and running conditions. It will be changed and updated according to the appropriate value. This updated value is saved even when the main switch is turned off when cancelled, and the updated upper limit value b
Using est0, the initial control input calculating unit calculates the initial control input amount U (0) at the next set ON or resume ON by the following formula. U (0) = V * a / best0 (28) Here, V is the vehicle speed when the switch is ON, the target vehicle speed when the switch is set, and the actual vehicle speed when the resume is ON when the resume is performed. Further, a is a constant relating to the vehicle dynamic characteristics.

As described above, by updating the initial control input characteristic best0 by the coefficient width correcting means, the initial control input characteristic according to the type of vehicle to be mounted can be set, and when the set is ON or the resume is ON. By calculating the initial control input amount, it is possible to reduce the vehicle speed at the time of setting or resuming, and to reduce the overshoot etc. at the time of resume due to this drop, and realize accurate constant speed traveling control. it can. It should be noted that it is not necessary to use the same value for increasing and decreasing the upper limit value and the lower limit value, and different values may be used for each. Alternatively, it may be obtained by multiplying by a certain rate.

Hereinafter, FIGS. 30 and 31 are road experiment data using the control input coefficient determining means. Control formula is formula
The initial value of best, best0, given in (24), was given as 0.2315. The experimental car is a 2000cc turbo car (205/6400 (PS / rpm)). FIG. 30 shows a set operation on a flat road at a vehicle speed of 80 km / h. Although the control input characteristic best decreases at the time of setting, it stops at a certain constant value, and stable constant speed traveling control is realized.
FIG. 31 shows the results of the on-road experiment with respect to changes in the road surface slope while the test vehicle is running at a target vehicle speed of 100 km / h. It can be seen that the estimated value best decreases as the road gradient approaches the uphill and increases as it descends. Along with this, the control input to the actuator has increased or decreased, but the vehicle speed is constant and the target vehicle speed is accurately followed. These experiments confirmed the effectiveness of the algorithm to change the control input characteristics. Next, a running experiment using a control algorithm having a target trajectory automatic correction method and a control gain automatic change rule was conducted on two vehicle models with the same software. The control equation is given by equation (24), and the target track vehicle speed is given by equation (26). Also, L = 360m
sec, best0 = 0.2315. Figures 32 to 35 and 36 to 39 show 3000cc vehicles (280/6200 (PS / rpm)) and 3000cc, respectively.
The result of the running test on the chassis of the car (180/6000 (PS / rpm)) is shown. 32 and 36 show the control results of the 100 km / h set operation and the 50 km / h to 100 km / h resume operation at + 3% in both figures. 33 and 37 show the set operation and the resume operation under the same conditions as in FIG. 32 at 0% and -3%. In addition, Fig. 35 and Fig. 39 show + 3% while driving at the target vehicle speed of 100km / h →
It is the result of the vehicle speed response experiment when the gradient changes suddenly from -3%, -3% to + 3%. From the above results, stable and accurate constant-speed running control can be performed even if the vehicle type changes with the same software or the road surface slope changes, and the target can be achieved at the time of resume without overshooting with the desired response waveform. The vehicle speed has been reached, and we were able to provide a constant-speed running control device that is robust against changes in the type of vehicle installed and changes in the road surface gradient.

[0043]

As described above, according to the present invention, a plurality of response waveform trajectories are given in advance, and the trajectory following type time delay
By constructing the control, the driver can select a desired response, and it is possible to obtain an acceleration feeling at the time of resume in accordance with the driving feeling of the driver. In addition, the present invention is a resume ON
By changing the convergence time according to the magnitude of the subsequent vehicle speed deviation, there is an effect that it is possible to realize constant-speed running control with a comfortable ride.

Further, according to the present invention, the target trajectory at the time of resume is automatically corrected to a trajectory according to the ability of the vehicle on which the vehicle is mounted. This has the effect that a resume response can be obtained. In addition, when the target vehicle type covers a wide range, the unknown input distribution characteristic b changes to the control input characteristic best.
There is an effect that constant speed running control that favorably follows the target track vehicle speed can be realized by changing the best by the control input coefficient determining means at this time.

Further, according to the present invention, the initial control input characteristic best0
Is updated by the coefficient width correction means, and the initial gain is calculated by the initial control input calculation means according to the vehicle type to be mounted,
By calculating the initial control input amount when the set is on or when the resume is on, it is possible to reduce the vehicle speed drop at the time of set or resume and the overshoot etc. at the time of resume due to this drop, This has the effect that accurate constant-speed traveling control can be realized. In addition, by providing the trajectory with the return acceleration α in the target trajectory setting means, the convergence time of the target trajectory at the time of resume can be changed according to the magnitude of the vehicle speed deviation, and the capability of the vehicle to be mounted. By changing the return acceleration according to the road environment and the road environment, it is possible to obtain a stable and smooth resume response without presetting a target trajectory for each vehicle type. Further, by decreasing the acceleration α at the time of convergence by the convergence acceleration changing means,
The amount of change when the target track vehicle speed converges to the target vehicle speed is small,
The discontinuity caused by the sudden change of the target trajectory is eliminated, and it is possible to suppress overshoot and undershoot when the resume response is converged, and it is possible to realize constant-speed running control without discomfort during resume. Further, when the vehicle speed deviation becomes equal to or greater than a certain value by the initial target track changing means, the target track vehicle speed is changed to the actual vehicle speed value at that time, thereby eliminating the effect of dead time due to slack of the throttle wire. The smooth resume response control can be performed without unnecessary acceleration.
This has the effect of realizing constant-speed running control that follows the target track vehicle speed well.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a concept of a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a concept of a second embodiment of the present invention.

FIG. 3 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 4 is a control block diagram of a trajectory following TDC.

FIG. 5 is a block diagram of a control law of a trajectory tracking type time delay controller.

FIG. 6 is a diagram showing a normalized target trajectory given in the first invention.

FIG. 7 is a diagram showing target vehicle speed calculating means used in the second invention.

FIG. 8 is a control conceptual configuration diagram according to an embodiment of the present invention.

FIG. 9 is a block diagram showing the concept of a third embodiment of the present invention.

FIG. 10 is a flowchart showing the basic procedure of the target trajectory correction means used in the third embodiment.

FIG. 11 is an explanatory diagram of a target trajectory correction method used in the third embodiment.

FIG. 12 is a block diagram showing the concept of a fourth embodiment of the present invention.

FIG. 13 is a block diagram showing the concept of a fifth embodiment of the present invention.

FIG. 14 is an explanatory diagram of a target trajectory correction method used in the fourth embodiment.

FIG. 15 is a block diagram showing the concept of a sixth embodiment of the present invention.

FIG. 16: Input characteristics of controller (control input characteristics)
The figure which shows the relationship between the target track vehicle speed Vd and the vehicle speed V which is the output of the controlled object when best is larger than the actual input distribution characteristic b.

FIG. 17 is a flowchart showing the procedure of coefficient width correction means and initial control input calculation means used in the sixth embodiment.

FIG. 18 is a flow chart showing the procedure of coefficient width correction means and initial control input calculation means used in the sixth embodiment.

FIG. 19 is a block diagram showing the concept of a sixth embodiment of the present invention.

FIG. 20 is a block diagram showing the concept of a seventh embodiment of the present invention.

FIG. 21 is a conceptual diagram showing the vehicle speed response and control input amount of the initial target trajectory changing means of the seventh embodiment.

FIG. 22 is a diagram showing the results of an experiment on a chassis run by a track-following time delay control.

FIG. 23 is a diagram showing a result of an on-chassis traveling experiment using a trajectory following type time delay control.

FIG. 24 is a diagram showing a result of an on-chassis traveling experiment using a trajectory following type time delay control.

FIG. 25 is a view showing the results of an on-chassis traveling experiment using a trajectory-following time delay control.

FIG. 26 is a view showing a result of an on-chassis traveling experiment with a trajectory-following time delay control.

FIG. 27 is a diagram showing the results of an on-chassis running experiment using a trajectory following type time delay control.

FIG. 28 is a view showing a result of an actual vehicle test by each means for changing a target track.

FIG. 29 is a view showing a result of an actual vehicle test by each means for changing a target track.

FIG. 30 is a diagram showing a setting operation at a vehicle speed of 80 km / h on a flat road.

[Fig. 31] A diagram showing road experiment results with respect to a change in road surface gradient while the test vehicle is traveling at a target vehicle speed of 100 km / h.

FIG. 32 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 33 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 34 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 35 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 36 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 37 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 38 is a view showing a result of a running test on a chassis in a resume operation.

FIG. 39 is a view showing a result of a running test on a chassis in a resume operation.

[Explanation of symbols]

 11 command circuit 12 vehicle speed detection circuit 13 target value setting circuit 14 control amount calculating means 15 target trajectory setting means 16 actuator 17 throttle valve 18 vehicle body 19 target trajectory selecting means 121 vehicle speed detecting circuit 122 target value setting circuit 123 target trajectory setting means 124 convergence Acceleration changing means 125 Control amount calculating means 126 Actuator 127 Body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number Japanese patent application No. 3-150039 (32) Priority date Hei 3 (1991) June 21 (33) Priority claim country Japan (JP) (72) Inventor Osamu Ito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (15)

[Claims] 1. A vehicle speed detection circuit for detecting an actual vehicle speed, an actuator for adjusting the vehicle speed through a throttle valve,
A constant speed running start signal, a constant speed running release signal, and a command circuit that issues a resume signal that returns to the vehicle speed at the previous constant speed running after releasing the constant speed running, and the target vehicle speed by the constant speed running start signal of the command circuit. A target value setting circuit for setting
As the output of the vehicle speed detection circuit becomes the target vehicle speed, the control amount input to the actuator, by assuming that the variation of unknown terms such as plant modeling error and disturbance is constant for a minute L time, Using the term of the known part before the minute time, a type of adaptive control that estimates an unknown term, the magnitude of the control input characteristic best that determines the magnitude of the control gain, the input to the actuator, Calculated by a control law (hereinafter referred to as "time delay control") characterized in that the stability of the control system is compensated by setting the output to a speed equal to or more than the plant gain value of the model. The control amount calculating means and the trajectory of the actual vehicle speed to reach the target vehicle speed by the resume signal of the command circuit are set as two or more preset preset trajectories of different shapes and function as a function of time. Therefore, it is provided with the target trajectory setting means and the target trajectory selecting means that allows the driver to select a desired trajectory from the two or more different shapes of the trajectory, and the one trajectory selected by the target trajectory selecting means is provided. On the other hand, a constant speed traveling control device for a vehicle, which converges to a target vehicle speed so that the actual vehicle speed follows. 2. A vehicle speed detecting circuit for detecting an actual vehicle speed, and an actuator for adjusting the vehicle speed through a throttle valve.
A constant speed running start signal, a constant speed running release signal, and a command circuit that issues a resume signal that returns to the vehicle speed at the previous constant speed running after releasing the constant speed running, and the target vehicle speed by the constant speed running start signal of the command circuit. A target value setting circuit for setting
The actual vehicle speed is set to the target vehicle speed by the control amount calculation means for calculating the control amount input to the actuator by the time delay control () and the resume signal of the command circuit so that the output of the vehicle speed detection circuit becomes the target vehicle speed. The target trajectory setting means for giving a trajectory to reach the destination as a trajectory of two or more preset convergence times with different convergence times, the target vehicle speed immediately after recognizing the resume signal of the command circuit, and the actual vehicle A vehicle constant speed characterized by comprising return vehicle speed deviation detecting means for reading deviation from speed and selecting a target trajectory having a different convergence time to the target vehicle speed of the target trajectory setting means according to the magnitude of the deviation. Travel control device. 3. The target trajectory setting means sets in advance two or more target trajectories whose vehicle speed axes are normalized and which have different settling times, that is, trajectories having a smooth response waveform at the time of resume, and are resumed. 3. The vehicle constant speed traveling control device according to claim 1, wherein the target track vehicle speed is calculated according to a deviation between the actual vehicle speed when the switch is ON and the target vehicle speed. 4. The target track setting means calculates a target track vehicle speed which is a settling time corresponding to a vehicle speed deviation by giving an acceleration α when the vehicle speed converges to a target vehicle speed during resume. Item 3. A vehicle constant speed traveling control device according to item 1 or 2. 5. A vehicle speed detection circuit for detecting an actual vehicle speed, an actuator for adjusting the vehicle speed through a throttle valve,
A target value setting circuit for setting the target vehicle speed Vset, a target trajectory setting means for giving one target trajectory vehicle speed Vd (t) at the time of resuming, where t is time, and this Vd (t) and the output V of the vehicle speed detection circuit. The deviation from (t) is e (t), and the deviation feedback coefficient is ki.
(> 0, i = n-1 to 0), the target deviation characteristic is given by the nth-order differential equation of the deviation e (t) with the deviation feedback coefficient being each constant, and the control input characteristic best When the value is set to a value of at least 1/2 times the maximum value of the plant gain, V (t) becomes the target vehicle speed Vset along the target trajectory given by Vd (t), to the actuator. The controlled variable U (t) is controlled by the time delay control to the value of U (t) before the minute time L and the minute time L of the actual vehicle speed V (t).
Previous n-th derivative value, n-th derivative value of the target track vehicle speed, the target error characteristic and the control input characteristic best, using the control amount calculation means, the deviation between the target track vehicle speed and the actual vehicle speed Alternatively, at least one of the differential values up to the nth level of the deviation and the average speed and position of the actuator are evaluated,
A constant speed running for a vehicle, characterized by further comprising: a target trajectory correction means for newly obtaining the target track vehicle speed Vd (t) using one or more trajectory correction rules that give a new target track vehicle speed Vd (t). Control device. 6. In the trajectory correction rule of the target trajectory correcting means, at least one of the deviation or the differential value of the deviation which is an input variable is compared with a set value, and the average speed and position of the actuator are compared with the set value. , The target track vehicle speed Vd (t), which is an output variable, is given as a real value by judging the magnitude relation with respect to each set value, or a linear or non-linear function using at least one of the deviation or the differential value of the deviation. 6. The vehicle constant speed travel control according to claim 5, wherein the target track vehicle speed Vd (t) is obtained by using a variable determination rule in which the input / output variable is represented by a fuzzy variable. apparatus. 7. A target track vehicle speed Vd in the target track setting means.
(t) is the vehicle speed on a straight line given by the constant acceleration α, and the acceleration α is set so that the target trajectory smoothly converges to the target vehicle speed when the deviation between the target vehicle speed and the actual vehicle speed becomes less than a certain set value.
The constant speed running control device for a vehicle according to claim 5 or 6, further comprising a convergent acceleration changing means for changing. 8. The vehicle constant according to claim 5, wherein the convergent acceleration changing means reduces the acceleration when the deviation between the target vehicle speed and the actual vehicle speed at the time of resume is less than a set value. Speed control device. 9. Resuming is turned on in the target trajectory setting means.
When the deviation e (t) measured from time exceeds a certain set value, the target track vehicle speed is translated so as to match the actual vehicle speed at that time, and a new target track vehicle speed is set as the initial target. The vehicle constant speed traveling control device according to claim 5 or 6, further comprising a trajectory changing means. 10. A vehicle speed detection circuit for detecting an actual vehicle speed, an actuator for adjusting the vehicle speed through a throttle valve, a target value setting circuit for setting a target vehicle speed Vset, a time t, and a target track vehicle speed Vd ( target trajectory setting means for giving t), the deviation between this Vd (t) and the output V (t) of the vehicle speed detection circuit is e (t), and the error feedback coefficient is ki (>
0, i = n-1 to 0), the target deviation characteristic is given by the nth-order differential equation of the deviation e (t) where the deviation feedback coefficient is each constant, and the value of the control input characteristic best used when calculating the control gain is given. When the maximum value of the plant gain is at least 1/2 or more, the control amount to the actuator is such that V (t) becomes the target vehicle speed Vset along the target trajectory given by Vd (t). U (t) is controlled by the time delay control
The value of U (t) before the minute time L and the value of the actual vehicle speed V (t) before the minute time L
n-th derivative, the n-th derivative of the target track vehicle speed, using the target error characteristic and the control input characteristic best, the control amount calculating means to calculate, the deviation between the target track vehicle speed and the actual vehicle speed, or At least one of the derivative values of this deviation up to the nth order,
A control input coefficient determining means for determining the control input characteristic best by using one or more coefficient determining rules for evaluating the average velocity and position of the actuator and providing the control input characteristic best. Constant speed running control device for a vehicle. 11. In the coefficient determination rule of the control input coefficient determination means, at least one of the deviation or the differential value of the deviation which is an input variable is compared with a set value, and the average speed and position of the actuator are compared with the set value. Then, by determining the magnitude relationship for each set value, the control input characteristic best which is an output variable is given as a real value, or a linear or non-linear function is calculated using at least one of the deviation or the differential value of the deviation. 11. The vehicle constant speed traveling control device according to claim 10, wherein the control input characteristic best is obtained by using a variable determination rule in which the input / output variable is represented by a fuzzy variable. 12. A vehicle speed detection circuit for detecting an actual vehicle speed V (t) (t is time), an actuator for adjusting the actual vehicle speed, a target value setting circuit for setting a target vehicle speed Vset, and a target trajectory at the time of resume. A target trajectory setting means for giving a vehicle speed Vd (t), a deviation between the target vehicle speed Vd (t) and the actual vehicle speed V (t) is e (t), and an error feedback coefficient is ki (> 0, i = n). -1 ~
0), the target deviation characteristic is given by the n-th order differential equation of the deviation e (t) where the deviation feedback coefficient is each constant, and the value of the control input characteristic best used when calculating the control gain is set to a small maximum value of the plant gain. When the value is 1/2 times or more, V
(t) is the target vehicle speed Vset along the target trajectory given by Vd (t)
So that the control amount U (t) to the actuator is
By the time delay control, the value of U (t) before the minute time L, the nth derivative of the actual vehicle speed V (t) before the minute time L, the nth derivative of the target track vehicle speed, and the target Using the error characteristic and the control input characteristic best, the control amount calculating means for calculating, the deviation e (t), or at least one of the differential values of the deviation e (t) up to the nth level, and the average movement of the actuator A control input coefficient determining means that evaluates the speed and the position and gives the control input characteristic best, calculates the control input characteristic best using one or more coefficient determination rules, and the calculated control input characteristic best. Depending on the change state of the control input characteristic, the value of the initial control input characteristic best0, which is the maximum value, and the minimum value of the control input characteristic best1 are changed to narrow down the fluctuation width of the control input characteristic best. , The initial control input amount U (0) at the time of resume is Characterized by including an initial control input calculating means for output,
Vehicle constant speed control device. 13. In the initial control input calculating means, when the vehicle speed at the time of setting and resuming is V0 and a is a constant, the initial control input U (0) uses V0 * a as the initial control input characteristic best0.
13. The vehicle constant speed traveling control device according to claim 12, wherein the constant speed traveling control device is given by / best0. 14. The coefficient width modifying means is characterized in that the initial values of the maximum value best0 and the minimum value best1 of the control input characteristic are the maximum value and the minimum value of the fluctuation width of the plant gain of all the target vehicle types. The vehicle constant speed traveling control device according to claim 12. 15. The vehicle constant speed traveling control device according to claim 1, wherein the control period is a minute time L and the control period is discretized.