JPH08513B2 - Constant-speed running control device for vehicle - Google Patents

Description

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

2. Description of the Related Art Conventional vehicle constant-speed traveling control devices basically use RID control so that the vehicle speed sensor detects the actual vehicle speed, the target vehicle speed is set according to the driver's intention, and the actual vehicle speed converges to the target vehicle speed. Various feedback controls are 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 the convergence to the target vehicle speed is always constant. But it will be different.
Therefore, in order to obtain a constant convergence to the target vehicle speed regardless of the change in the vehicle dynamic characteristic, a plurality of control gains for calculating the operation amount to the actuator that drives the throttle valve are changed. In addition, it is necessary to make adjustments according to changes in running load, and this adjustment requires a great deal 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 difference between the current throttle opening and the throttle opening required for steady running on level ground is calculated. , The traveling load is calculated, and the forward control system P is calculated according to the increase of the traveling load.
Increase the proportional constant and integral constant of + I to reduce the 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,
We are trying to realize good constant-speed driving control.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a conventional constant speed traveling control device based on feedback control such as P + I-P + D control, the operation required for the controlled object has a target point (vehicle speed). PTP (Point to Po to move from fixed point to fixed point
int) operation. That is, the guaranteed operation is
CP that only moves between two points from a certain vehicle speed to a set target vehicle speed, and the target point moves continuously
(Continuous Path) There is a problem that it is not suitable for operation. That is, for the target locus until the vehicle speed converges to the target vehicle speed, not guarantee the follow-up property, even in any state for its constant and convergence, i.e. along the same target locus convergence Let's do the conventional PID
Very difficult to control.

The present invention has been made by paying attention to the conventional problems as described above, and introduces the concept that the variation of a minute time is constant, and is a kind of adaptive control for estimating an unknown term, that is, a time delay. -By using the control, the target response waveform locus when the vehicle speed converges to the target vehicle speed is given as a function of time, and the error vector is defined with this given locus as a reference to determine the gear position and running load. It is an object of the present invention to provide a constant speed running control device for a vehicle that can always converge to a target vehicle speed with a constant convergence along a given locus even with respect to changes in vehicle dynamic characteristics due to changes in To do.

Means for Solving the Problems In order to achieve the above object, the present invention has a vehicle speed detecting means for detecting an actual vehicle speed of a vehicle, a target value setting means for setting a target vehicle speed according to a driver's intention, and a vehicle speed of the target vehicle speed. Target locus setting means for giving a target locus when converged to, and a control amount for an actuator for driving the throttle valve so that the actual vehicle speed matches the target vehicle speed, the vehicle speed detected by the vehicle speed detecting means, and the target The target locus vehicle speed given by the locus setting means is used, and a control amount computing means for computing by a locus tracking type time delay control control law that makes these errors zero is provided.

Action The present invention has the above-described configuration to set a trajectory of a desired response waveform between normalized target points in advance, that is, a desired response waveform at the time of return, and a time delay using the difference between the target trajectory and the actual vehicle speed as an error vector.・ Controlling, that is, track-following time delay control, calculates the manipulated variable of the throttle valve opening so that the convergence to the target vehicle speed is affected by changes in gear position and running load. Instead, the actuator can be controlled so that it always coincides with the locus of the desired response waveform, and stable constant-speed traveling control with good convergence can be performed.

Embodiment Hereinafter, an object vehicle will be 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 one embodiment of the present invention. The trajectory of the desired response waveform at the time of resume is given by the target trajectory setting means 14, the actual vehicle speed is detected by the vehicle speed detecting means 11, the target vehicle speed is set by the target value setting means 12, and the output of the target trajectory setting means and the actual vehicle speed are set. From the speed and the target vehicle speed, the actuator is controlled by the control amount calculation means 13 so that the actual vehicle speed matches the target vehicle speed with a desired response waveform.
Calculate the controlled variable to 15. FIG. 2 is a system configuration diagram of an embodiment of the present invention. Reference numeral 28 in the figure denotes a control circuit including a CPU, ROM, RAM, I / O, etc., which performs constant-speed traveling control by input signals from various sensors and switches. 23 is a main switch for supplying power to the actuator power supply and control circuit, 21 is a dual-purpose switch for setting a target vehicle speed and a coast switch for lowering the target vehicle speed setting value, and 22 is a target vehicle speed. It is a switch that doubles as a resume switch that returns and an accelerator switch that increases the set value of the target vehicle speed. 25 is a brake switch that is turned on when the brake is stepped on, 24 is a cancel switch that releases the set and resume functions, 26 is a vehicle speed sensor that detects the actual vehicle speed, and 27 is a gear position in the neutral or parking position. A neutral parking switch that detects that there is a solenoid 29 is a solenoid that supplies or shuts off power to the actuator 210 when starting or ending constant-speed traveling. When the constant speed traveling control is started by turning on the set switch 21 or the resume switch 22, the solenoid 29 is turned on by the control circuit 28, and the difference between the actual vehicle speed of the vehicle speed sensor 26 and the set target vehicle speed is calculated. Then, the target locus vehicle speed can be obtained from this value and the normalized target locus stored in the ROM in advance. Then, the control amount is calculated so that the error between the target locus vehicle speed and the actual vehicle speed becomes zero, and is output to the actuator 210.
Then, by driving this actuator 210, the throttle valve of 211 is opened and closed to adjust the fuel supply amount to the engine, thereby realizing constant speed traveling control.

FIG. 3 is a control block diagram of the above embodiment. Based on this figure, the control concept of the trajectory tracking type time delay control (TDC), which is a type of adaptive control, will be described. The actuator 35 adjusts the opening of the throttle valve 36 by the target opening input U to control the vehicle speed. The vehicle speed V is read by the vehicle speed sensor 33 and is stored in the target vehicle speed setting 31 with the actual vehicle speed when set by the target value setting means as the target vehicle speed R. When the resume switch 22 is turned on, from the difference between the actual vehicle speed V and the target vehicle speed R at that time, the normalized target trajectory map 32
The target trajectory vehicle speed Vd is given. This target locus vehicle speed Vd is
The desired response waveform at the time of convergence is given in time series, and the control amount U to the actuator 35 is calculated by the TDC control formula 34 so that the deviation e between the actual vehicle speed V and the target trajectory vehicle speed Vd becomes zero.

By the above operation, the actual vehicle speed V can follow the target vehicle speed R with desired response characteristics, that is, the speed control can be performed so as to follow the target locus vehicle speed Vd, and the constant control is always stable and constant. High-speed driving control can be realized. Next, this trajectory-following time delay control (below
The control system design of TDC will be explained.

First, input the target opening to the throttle valve 36 by 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.

This TDC is an effective controller for a system with unknown dynamic characteristics. Below, for a non-linear plant, a trajectory-following control law suitable for CP operation is sought. This is explained in detail in Osamu Ito et al., "Proposal of Time Delay Control for Trajectory Tracking and Its Application to Robot Manipulator Control" (Journal of Engineering Society, 55/12/1989).

First, if Equation (1) is corrected to the time domain, it is assumed that V (t) = − aV (t) + bu (t) (2) a, b is unknown and the fluctuation range is known as follows. .

0 <a min <a <a max (3) 0 <b min <b <b max (4) Here, the target locus vehicle speed of the vehicle speed V is Vd, and this deviation is defined as an error e, and is defined by the following equation.

e = Vd−V (5) From the equations (2) and (5), the following equation that governs the dynamic characteristic of the error is obtained.

e (t) = Vd (t) + aV (t) −bU (t) (6) Here, if U can be determined so as to always satisfy the following equation, Vd (t) + aV (t) −bU ( t) = − Ae · e (t) (7) The following equation is obtained from the equations (6) and (7).

e (t) =-Ae.e (t) Ae> O (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 (d + aV + Ae · e) (9) However, the unknown variables a and b are included in the above equation,
The control input U cannot be determined as it is. Therefore, let us consider estimating this unknown part.

First, the equation (2) is divided into an unknown part aV and other parts as follows.

aV = − + bU (10) Here, assuming that L is a minute time delay and aV = h, the following is assumed.

h (t) ≈h (t−L) (11) From the equations (10) and (11), the unknown term h is estimated by the following equation.

(T) =-(t-L) + bU (t-L) (12) Substituting this estimated value into the equation (9) gives the control law of the time delay control regarding the constant speed traveling control by the following equation. .

U (t) = U (t−L) + b ⁻¹ {−V (t−L) + Vd (t) + Ae · e} (13) However, the equation (13) for calculating the control input U is an unknown term b.
, The control input U (t) to the actuator cannot be determined as it is. Therefore,
The estimated value of b that makes the control system stable is substituted into equation (14) to obtain the actual control input.

 That is, the control input is given by the following equation.

U (t) = U (t−L) + ^{− 1} {−V (t−L) + Vd (t) + Ae · e}> O (14) A block diagram showing in detail the control law given by the equation (14). When a control input U is applied to the controlled object 43 shown in FIG. 4, the vehicle speed V is output. The deviation between the target locus vehicle speeds Vd and V is e, the error convergence is guaranteed by the target error characteristic insertion unit 41 by the Vd and e, and the nonlinear term is estimated by the unknown characteristic cancellation unit 42 by the actual vehicle speeds V and U. Thus, the locus-following time delay controller 44 is configured, and the control input U to the controlled object 41 that has a desired response waveform such that the deviation e becomes zero is calculated.

That is, −V (−L) and U (t−L) are unknown part cancellation terms of the plant, and d (t) + Ae · e
Is an error dynamic characteristic insertion term for an arbitrary target trajectory.

Next, the derivation of the estimated value for stabilizing the entire control system will be described. First, Laplace transform of equation (14) gives the following equation.

(1-e- ^LS ) U (S) = {-(Se- ^LS + Ae) V (S) + (S + Ae) Vd (S)} (15) Further, the equation (2) is also Laplace transformed.

U (S) = b ⁻¹ (S + a) V (S) (16) From the equations (15) and (16), the following equation is obtained.

{B- ¹ (S + a) (1-e- ^LS ) + Se- ^LS + Ae} V (S) = (S + Ae) Vd (S) (17) Here, the Paddy approximation is used in the equation (17). That is, the following equation is substituted.

^{e -LS = (2-LS)} / (2 + LS) (18) Therefore, the condition under which the above equation is stable is determined by the Rouss's stability determination.

First, let F (S) be the denominator of equation (19), and sort out S.

^{F (S) = (2b -1} -1) LS 2 + {(2ab -1 + Ae) L + 2} S + 2Ae = A 0 S 2 + A 1 S + A 2 (20) where (3) (4) (8) And from the parameter range of equation (14), it can be seen that A ₁ and A ₂ are positive,
The following equation is the necessary and sufficient condition for stability.

A ₀ = (2b ⁻¹ −1) L> 0 (21) Therefore, the condition of is given by the following equation.

> B / 2 (22) Therefore, must be taken to be 1/2 or more of the true value. Therefore, considering the parameter range of the equation (4), the equation (22) becomes the following equation.

> B max / 2 (23) From the above, by using this estimated value and the control input U obtained by the equation (14), a response satisfying the error dynamic characteristic of the equation (8) can be obtained.

Based on this control law, the results of simulating changes in the gradient are shown in FIGS. 5 and 6, for example. As a comparison, FIG. Figure 8 shows the simulation results based on the PID control law.

FIGS. 5 and 7 show the simulation results when the slope is 3% down, and FIGS. 6 and 8 show the simulation results when the slope is 3% up.

The following values were used for a and b corresponding to the equation (1).

Up: a = .0157, b = .0078 Down: a = .0142, b = .0314 For this control target, simulation of trajectory following time delay control was performed with the following parameters.

= .06, Ae = .116, L = 0.2 (sec) Here, Vd in FIGS. 5 and 6 is a target locus, and V is a simulation result. As can be seen from this, it can be said that the control system is very robust because it can obtain almost the same characteristics even when the gradient changes.

On the other hand, the downlink shows almost the same response waveform (7th
Figure) PID control was performed. As can be seen from this result, even if the settling time is the same, the operation input U is greatly accelerated and becomes a control that gives the driver anxiety. In addition, it causes an overshoot on the uphill (Fig. 8).

From the above results, the trajectory following TDC control is a control system that is stronger against the fluctuation of the control target than the conventional PID control and can give a satisfactory acceleration feeling.

It should be noted that the control target may be secondary or higher and may have dead time.

EFFECTS OF THE INVENTION As is clear from the above description of the embodiment, the present invention provides a desired response waveform locus and constructs a locus tracking type time delay control to change the gear position and the running load. Regardless of fluctuation, it has the effect that constant convergence to the target vehicle speed is always kept constant, stable and good followability is achieved, and riding comfort is good, that is, constant speed traveling control with a small amount of change in throttle valve opening can be realized. .

[Brief description of drawings]

FIG. 1 is a configuration diagram showing the concept of a vehicle constant-speed traveling control device according to an embodiment of the present invention, and FIG. 2 is an overall configuration diagram of the same, and FIG.
FIG. 4 is a control block diagram, FIG. 4 is a block diagram of a control law of a trajectory tracking type time delay controller, and FIGS. 5 and 6 are diagrams showing simulation results of an embodiment using the present invention. FIG. 7 and FIG. 8 are diagrams showing simulation results using the conventional PID control. 11 …… Vehicle speed detection means, 12 …… Target value setting means, 13 …… Control amount calculation means, 14 …… Target locus setting means, 15 …… Actuator, 21 …… Set coast switch, 22 …… Resume accelerator Switch, 26 ... Vehicle speed sensor, 28 ...
… Control circuit, 210 …… Actuator, 211 …… Throttle valve.

Claims (1)

[Claims] 1. A vehicle speed detecting means for detecting an actual vehicle speed, an actuator for adjusting the vehicle speed, a target value setting means for setting a target vehicle speed, and an actuator for adjusting the output of the vehicle speed detecting means to the target vehicle speed. A control amount calculating means for giving a control input by a time delay control, which is one of the adaptive controls, and a target given by a function of time as a desired shape of the locus at the time of speed collection to the target vehicle speed at the time of resume. A vehicle constant speed traveling control device comprising: trajectory setting means, which converges the actual vehicle speed to a target vehicle speed so that an error from the actual vehicle speed becomes zero with reference to the given trajectory.