JPH04108040A - Constant speed running device for vehicle - Google Patents

Abstract

PURPOSE:To reduce labor for tuning, overshoot and fluctuation of a useless throttle opening, even when dynamic characteristic of a plant and a kind of a vehicle are changed, by controlling an actuator which changes a throttle opening from actual and target speeds of the vehicle and a present position of the actuator. CONSTITUTION:An actual speed of a vehicle is detected by a means 1, and on the other hand, a target speed is set by a means 2. A target control angle signal 31 is output to an actuator 3 from the actual and target speeds of the vehicle by a controller while changing a throttle opening of an engine by the actuator 3. Further, actuator displacement 36 is transmitted to the throttle opening by a throttle mechanical part 5. When a constant speed running command signal 30 is input from a constant speed running device 4, an actual speed signal 35 and a target speed signal 29 are detected by the controller 9 to output the target control angle signal 31 to the actuator 3 so that these actual and target speed signals are in agreement, and speed running control of making a car speed through a car body 7 is realized.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a vehicle constant speed running device that automatically controls the throttle opening so that the vehicle is driven at a constant speed. Regarding constant-speed running control systems for vehicles, various control systems have been devised to ensure the stability of plants such as engines and car bodies whose dynamic characteristics change over time. A control device for automatically driving a vehicle such as a car at a constant speed includes, for example, a vehicle speed detection means that detects the actual speed of the vehicle, and a device that sets a target vehicle speed according to the driver's will and starts the operation of the constant speed driving device. A target vehicle speed setting device inputs acceleration/deceleration relative to the stop and target vehicle speed, an actuator that changes the throttle opening of the vehicle engine, and a base that inputs the actual vehicle speed, target vehicle speed, etc.
A controller that outputs a drive signal to the actuator is used to detect the actual vehicle speed and throttle valve opening from them, calculate each change and the deviation between the actual vehicle speed and the target vehicle speed, and use a predetermined feedback gain. ,
Even if constant speed driving control is realized, in which the control amount is calculated and the actuator is driven to adjust the throttle valve opening so that the actual vehicle speed becomes the target vehicle speed, the problem that the invention is trying to solve still remains. In conventional constant-speed driving systems based on feedback control, the engine type, exhaust condition, reduction ratio, vehicle interior, air resistance value, etc. differ depending on the vehicle model in which it is installed. There was a problem in that tuning took a lot of time and money.Furthermore, with the PID control and control methods with a fixed reference model, which have been used for conventional constant speed driving control, it is difficult to control the control target on uphill or downhill. Dynamic characteristics fluctuate, making it difficult for the vehicle speed to converge smoothly during shooing, resulting in overshoot,
The present invention focuses on the conventional problem that the throttle opening varies more than necessary, deteriorating the ride feeling, and eliminates the trouble of tuning when the dynamic characteristics of the plant fluctuate or the car model changes. An object of the present invention is to provide a constant speed traveling device for a vehicle that has less unnecessary throttle opening fluctuations and less overshoot. A vehicle speed detection means for detecting the actual vehicle speed of the vehicle, a target vehicle speed setting means for setting the target vehicle speed, an actuator for changing the throttle and throttle opening of the vehicle's engine, and an actuator for detecting the current position of the actuator. a reference model calculation means comprising a position detection means, a controller for outputting a drive signal to the actuator based on the actual vehicle speed, the target vehicle speed, and the current position of the actuator, and the controller outputs a response trajectory until the target vehicle speed is reached; The control amount calculation means for outputting a target angle to the actuator from the actual vehicle speed, the target vehicle speed, the output of the reference model calculation means, and the current position of the actuator are the constituent elements, and the unknown part of the dynamic characteristic fluctuation of the plant is constant for a minute time. Assuming that, this variation term is estimated and the actuator target angle is given by time delay control.When calculating the actuator target angle in the controller, i dV/dt=a, which represents the dynamic characteristics of the engine, vehicle body, etc. to be controlled, is used.・V+
The estimated value of the unknown coefficient representing the characteristics of human power in issue B (■ indicates the actual vehicle MU is the throttle opening) is estimated when the absolute value of the deviation between the actual vehicle speed and the target vehicle speed is greater than a predetermined value and the first order of the deviation is When the absolute value of the difference is greater than a predetermined value, increase it by multiplying it by a value greater than 1, and when the sign of the deviation changes or the sign of the first-order difference of the deviation changes, multiply it by a value smaller than 1 and decrease it. This is characterized in that the unknown coefficients representing the characteristics of the input are controlled while following the estimated values of the unknown coefficients.

Effect of the Invention With the above-described configuration, the present invention detects the vehicle speed by giving the response characteristics at the time of resume etc. using a reference model, and calculates the control amount to the actuator so that the actual vehicle speed follows the target vehicle speed. When a controlled variable is given using the control law of time delay control, which introduces the concept that the L minute time fluctuation is negligibly small with respect to changes in the dynamic characteristics of the vehicle body, etc., the controlled variable is the controlled object. Even if the estimated value of the human power characteristic is used, the input characteristic of the controlled object is a force that fluctuates even when the same characteristic changes on a slope etc. When the absolute value of the deviation is larger than a predetermined value, the first difference of the deviation is increased by a value larger than ζif, and when the sign of the deviation changes or the first difference of the deviation is When the sign changes and exceeds a predetermined value ('L) By multiplying by a value smaller than 1 and decreasing the estimated value, the estimated value follows the input characteristics of the controlled object and is always stable and convergent. Even if the vehicle type changes and the plant gain time constant changes, accurate constant speed driving control can be achieved by simply adjusting a few input parameters. It can be installed in various vehicle models without any special tuning.ExampleThe following is a description of an example of the invention. This is a configuration diagram conceptually showing the configuration of an embodiment of the invention.It includes a vehicle speed detection means 1 that detects the actual vehicle speed of a vehicle, a target vehicle speed that is set, a start and stop of the operation of this constant speed traveling device, and a target vehicle speed. a target vehicle speed setting means 2 for inputting increases and decelerations; an actuator 3 for changing the throttle opening of the vehicle's engine; and a controller 9 for outputting a target control angle signal 31 to the actuator 3, such as the actual vehicle speed and target vehicle speed. , the controller 9 is equipped with a throttle mechanism section 5 that transmits the actuator displacement 36 to the throttle opening degree. The detection means 1 detects the actual vehicle speed signal 35 and the target vehicle speed 29 set by the target vehicle speed setting means 2, outputs the target control angle 31 to the actuator 3 so that the target vehicle speed 29 and the actual vehicle speed 35 match, and adjusts the vehicle speed through the vehicle body 7. Figure 2 is a control block diagram of the above-mentioned embodiment, and the plant 13 that is the object of the control consists of the actuator 3, the throttle mechanism 5, the engine 6, and the vehicle body 7. Opening input U
The actuator 3 operates and the throttle mechanism section 5
The throttle valve opening degree is adjusted through the vehicle body 7, and the actual vehicle speed V is outputted through the vehicle body 7.The target track vehicle speed generator 16 receives the target vehicle speed R as an input and outputs the target track vehicle speed Vtn, which is a transient response of the desired vehicle speed. Even though the time-delay controller 9 calculates a target control angle U of 1 degree for the actuator 3 so that the deviation e between the target track vehicle speed Vm and the actual vehicle speed V becomes zero, the target control angle U is the same as the one a minute time ago. The output sum is output in the form of the difference between the target control angle U of the actuator. Through the above operations, it is possible to perform speed control that follows the actual vehicle speed (target vehicle speed) with the desired response characteristics. Explaining the control law of construction and time delay control.
Let's build a car model and perform system identification. In this example, identification is performed using the frequency response method.The controlled object is a plant 13 (actuator 3, throttle mechanism 5, engine 6, and vehicle body 7), and this transfer function is G (S), and the actuator target angle distance is U. (
S), and the output vehicle speed is expressed as V (S). U (s
) is the output of the controller, and this G (S) is determined by the frequency response method described above.A Generally, the transfer function can be expressed by the following equation, but through identification experiments, the order n and coefficients at, as of equation (1) are determined.
, , , , an'b' l H+ l b*
As a result of the experiment, the transfer function of the controlled object is approximated as a first-order delay system as shown below. j4 Youcef-Toumi,
, and Ito, O,”On 1Jodel R
efference Control Using T
ime Delay for Non1inear S
systems with Unknown Dynam
ics'M, r, T, Report LMP/RBT
86-06. June, 1986. Ya special application Hei 2-82
Since it is described in detail in No. 414, I will omit it here, but based on the identification result of equation (2), limiting it to one person and one output,
Determine the time delay control adaptive control law f, and when formula (2) is expressed in the time domain, V(t)
= −a −V(t)+ b −U(t)
...(3) Also, assuming that the target trajectory vehicle speed is Vm, the deviation e is expressed as in the following formula.

e = V m (t) - V (t)
”...(4) Then, the time and
The control law of the delay control can be found as follows.
KV)-1Xt-r)+kr-'(-V(t-r)+V
a(t)+1-e) ”=(5) However, L
Kl is the constant revision that determines the characteristic of the deviation e, and τ is a minute time delay, and is the control period of the controller. br in equation (5) is the estimated value of the input characteristic in equation (2), and br is the estimated value of the input characteristic in equation (2). FIG. 3 shows an algorithm for increasing/decreasing br in the condition determination Lbr increase/decrease section according to the deviation e and the first-order difference Δe of the deviation e so as to approach the value b.

FIG. 4 11 The value of br/b is 2.5. 1. (k
From Figure 4, which shows the waveforms of the vehicle speed and throttle opening when resuming at C15, the larger br/b is than 1, the larger the overshoot becomes, and when br/b is too small than 1, the change in vehicle speed and throttle opening increases. A tendency for the operation of the opening degree to be unstable appears.When Lbr=b, the control performance is good.Next, we will explain the operation of the algorithm for increasing/decreasing br in Figure 3.4 If br/b is greater than 1, the deviation will occur. increases, so the deviation is larger than the predetermined value (C1 in Fig. 3) and the first-order difference of that deviation is larger than the predetermined value (C2 in Fig. 3). One ε
1) is smaller and the first-order difference of the deviation is a predetermined value (third
In the figure, when br/b is smaller than 1, br is multiplied by a coefficient (C2) smaller than 1 to reduce br and bring br closer to the unknown b. When the sign of the difference or the first difference of the deviation changes frequently, multiply br by a coefficient (C1) larger than 1 to increase br.
Based on the results of a vehicle type identification experiment shown in FIG. 5, when r approaches an unknown b, the response waveform of this example and the time-dependent change in br are shown for when the value of b is the maximum value and when the value is the minimum value. A stable throttle waveform with no overshoot can be obtained regardless of the change in b.
Even if the initial value of r is the maximum value of b, as shown in Figure 5, by increasing or decreasing br to bring it closer to the unknown b, b of the controlled object will change due to external factors such as running load or changes in slope. However, it is possible to realize a constant speed running system that always has no overshoot, small deviation in vehicle speed, and stable throttle opening operation.
The increase/decrease may be updated at intervals of integral multiples of the control cycle, rather than at intervals of each control cycle. In the process of calculating the control amount for the actuator so that the actual vehicle speed follows the target vehicle speed, the deviation and the deviation 1
By determining the condition of the floor difference, the estimated value br of the input characteristic S is increased or decreased, bringing br closer to the unknown b, and the effect is that there is no overshoot when the vehicle speed converges and the amount of variation in the throttle opening is small. 4. Even when the dynamic characteristics of the plant change, it is possible to always obtain a good response waveform, and when transferring this system to a different vehicle model, the tuning time and This has the effect of reducing costs and makes it easy to realize commonality between different vehicle models.

[Brief explanation of drawings]

Figure 1 shows the configuration of an embodiment of a constant speed traveling device for a vehicle according to the present invention. Figure 2 shows the response waveform of this embodiment and the change in br over time at the time of control plotting and the time of the minimum value in the same device. In the diagram, 1. Half-finished vehicle speed detection. 2. Target vehicle speed setting device! f, 3・
・Actuator Kyu 4. Constant speed running command device 5. Throttle mechanical suit 6. Engine, 7. Name of Kurama's agent Patent attorney Akira Okaji Haka 2 person Figure (ρ) by-b's head Rejame Kimono where the missing <h ToY-to's most noko \71 no Ginori Shinji-me no Katama t *lIl'lt Gin V, t fr t Rerenime Threshold 11'! j! '1

Claims (1)

[Claims] (1) A vehicle speed detection means for detecting the actual vehicle speed of the vehicle, a target vehicle speed setting means for setting the target vehicle speed, an actuator for changing the throttle opening of the vehicle's engine, and an actuator current position for detecting the current position of the actuator. a controller for outputting a drive signal to the actuator from an actual vehicle speed, a target vehicle speed, and a current position of the actuator; the controller includes a reference model calculation means for outputting a response trajectory until reaching the target vehicle speed , the actual vehicle speed, the target vehicle speed, the output of the reference model calculation means, and the control amount calculation means for outputting the target angle to the actuator from the current position of the actuator are the components, and the unknown part of the dynamic characteristic fluctuation of the plant is constant for a minute time. Assuming that Formula, dV/dt=-a・V+b・U (V is actual vehicle speed U
is the estimated value of the unknown coefficient b representing the characteristics of the input at the throttle opening) when the absolute value of the deviation between the actual vehicle speed and the target vehicle speed is greater than a predetermined value and the absolute value of the first-order difference of the deviation is a predetermined value. A vehicle characterized in that when the deviation is larger than the value, the vehicle is multiplied by a value larger than 1 to increase the value, and when the sign of the deviation changes or the sign of the first difference of the deviation is changed, the vehicle is multiplied by a value smaller than 1 to decrease the deviation. constant speed traveling device.