JP2004232570A - Vehicle acceleration control device and its acceleration control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve acceleration feeling improvement or the like at starting time etc. by improving response-performance against command acceleration. <P>SOLUTION: The control method comprises the steps of: operating command vehicle speed by numerically integrating the command acceleration by a command vehicle speed operation part 4a; keeping the command acceleration and data showing a relation between the command vehicle speed and throttle opening of a vehicle movement system 5 as the data of vehicle movement characteristic by a command throttle opening output part 4b; obtaining the command acceleration and the throttle opening fixed by the command vehicle speed as a command throttle opening from the keeping data; and controlling the acceleration in feedforward control by controlling the throttled opening by the command throttled opening. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an acceleration control device and an acceleration control method for a vehicle that travels following a preceding vehicle while maintaining the following distance.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as described in a specification, a drawing, and the like of the applicant's already-filed application (Japanese Patent Application No. 2002-207671), an inter-vehicle distance between a host vehicle and a preceding vehicle is detected by inter-vehicle distance detection means such as a laser radar. There has been proposed a vehicle having a follow-up traveling system configuration that travels following a preceding vehicle while maintaining the detected inter-vehicle distance at a predetermined target inter-vehicle distance corresponding to the vehicle speed.
[0003]
It has been considered that a control algorithm based on feedback control is used for acceleration control of a vehicle having such a kind of following travel system configuration.
[0004]
Next, a description will be given of an acceleration control device for a vehicle having such a following traveling system configuration when performing acceleration control of feedback control with reference to a block diagram of FIG.
[0005]
The inter-vehicle control ECU 1, which is provided with the instantaneous inter-vehicle distance by the inter-vehicle distance detection means (not shown), executes a computer process based on the inter-vehicle distance and the own vehicle speed (detected vehicle speed) to execute a predetermined target inter-vehicle distance corresponding to the own vehicle speed. The acceleration required to travel while following the preceding vehicle while maintaining the distance is calculated, and this acceleration is given to the throttle control ECU 2 as a commanded acceleration.
[0006]
The ECU 2 calculates the throttle opening according to the error by a computer process based on an error (control deviation) between the command acceleration and the acceleration (actual acceleration) obtained from the vehicle speed detected by a speed sensor (not shown). The command throttle opening is obtained as a command throttle opening (operation amount), and the command throttle opening is given to a vehicle motion system 3 including a throttle, an engine and the like.
[0007]
Then, the throttle of the vehicle motion system 3 is controlled to an opening corresponding to the command throttle opening, and the acceleration of the own vehicle is controlled to the command acceleration.
[0008]
By this feedback control, the acceleration of the own vehicle is feedback-controlled based on the error between the commanded acceleration and the actual acceleration so that the vehicle follows the preceding vehicle while keeping a predetermined inter-vehicle distance according to the own vehicle speed.
[0009]
[Problems to be solved by the invention]
However, in the case of the acceleration control of the feedback control, since the motion of the vehicle exhibits a non-linear behavior with respect to the opening degree of the throttle, for example, as shown in the characteristic diagram of the acceleration control in FIG. Large overshoot and undershoot occur in the acceleration, and the control result is not stable.
[0010]
In FIG. 5, the horizontal axis represents time, the vertical axis represents acceleration, a solid line a represents a commanded acceleration, and a solid line b represents an actual acceleration.
[0011]
Therefore, the response to the commanded acceleration is poor, and as a result, there is a problem that the acceleration feeling particularly at the time of starting is bad.
[0012]
Therefore, an object of the present invention is to improve responsiveness to a commanded acceleration and improve acceleration feeling at the time of starting or the like.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a vehicle acceleration control device according to the present invention includes command vehicle speed calculating means for calculating command vehicle speed by integrating command acceleration, the command acceleration and the command vehicle speed as data of vehicle motion characteristics. Command throttle opening output means for holding data indicating the relationship between the throttle opening of the vehicle motion system and the throttle opening determined by the command acceleration and the command vehicle speed as a command throttle opening from the held data. And the acceleration of the feed-forward is controlled by controlling the opening of the throttle according to the command throttle opening (claim 1).
[0014]
According to such a configuration, the actual acceleration is feedforward controlled based on the commanded acceleration by the commanded throttle opening of the commanded throttle opening output means, and the vehicle motion exhibits a nonlinear behavior with respect to the throttle opening. However, the actual acceleration is controlled with good responsiveness to the commanded acceleration, the responsiveness to the commanded acceleration is improved, and the acceleration feeling at the time of starting or the like is improved.
[0015]
Further, the vehicle traveling control device according to the present invention is characterized by further comprising a correction means for correcting the command throttle opening by a feedback control output proportional to a difference between the command vehicle speed and the detected vehicle speed (claim 2). .
[0016]
According to such a configuration, the correction of the feedback control by the correction means is added to the feedforward control described above, and the data error of the command throttle opening is not compensated by the feedforward control alone. Improvement is achieved, the response to the commanded acceleration is further improved, and the acceleration feeling at the time of starting and the like is further improved.
[0017]
The correction means may calculate a product of the command throttle opening and the feedback control output as a correction amount, and correct the command throttle opening by adding the correction amount to the command throttle opening. It is practical and preferable (claim 3).
[0018]
Further, in the vehicle acceleration control device according to the present invention, the data indicating the relationship between the commanded acceleration, the commanded vehicle speed, and the throttle opening is three-dimensional data of the commanded acceleration, the commanded vehicle speed, and the throttle opening. (Claim 4).
[0019]
According to such a configuration, the command throttle opening determined by the command vehicle speed and the command acceleration is easily derived from the command throttle opening output means as a so-called map output.
[0020]
In the vehicle acceleration control device having the following traveling system configuration, it is practical that the commanded acceleration is derived from the calculation of the following distance control (claim 5).
[0021]
Next, the vehicle acceleration control method according to the present invention calculates the command vehicle speed by integrating the command acceleration, and stores the command acceleration, the command vehicle speed, and the opening degree of the throttle of the vehicle motion system held as data of the vehicle motion characteristics. From the data indicating the relationship, the throttle opening determined by the command acceleration and the command vehicle speed is derived as a command throttle opening, and the command throttle opening controls the throttle opening to feed forward the acceleration. It is controlled (claim 6).
[0022]
According to such a configuration, the actual acceleration is feed-forward controlled based on the commanded acceleration, and the actual acceleration is controlled with good responsiveness to the commanded acceleration even if the motion of the vehicle shows a non-linear behavior with respect to the throttle opening. Thus, the response of the actual acceleration to the command acceleration is improved, and the acceleration feeling at the time of starting or the like is improved.
[0023]
Also, the vehicle acceleration control method according to the present invention is characterized in that the command throttle opening is corrected by a feedback control output proportional to the difference between the command vehicle speed and the detected vehicle speed (claim 7).
[0024]
According to such a configuration, the correction of the feedback control is added to the feedforward control, and the data error of the command throttle opening is not compensated only by the feedforward control. As a result, the response to the command acceleration is further improved, and the acceleration feeling at the time of starting or the like is further improved.
[0025]
Then, it is practical and preferable to calculate the product of the command throttle opening and the feedback control output as a correction amount, and correct the command throttle opening by adding the correction amount to the command throttle opening ( Claim 8).
[0026]
Further, in the vehicle acceleration control method according to the present invention, the data indicating the relationship between the commanded acceleration, the commanded vehicle speed, and the throttle opening is a three-dimensional data of the commanded acceleration, the commanded vehicle speed, and the throttle opening. (Claim 9).
[0027]
According to such a configuration, the command throttle opening determined by the command vehicle speed and the command acceleration is easily derived as a so-called map output.
[0028]
In the acceleration control of the vehicle having the following traveling system configuration, it is practical that the command acceleration is derived from the calculation of the following distance control (claim 10).
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. 1 is a block diagram, FIG. 2 is a data structure diagram of a throttle opening map section of FIG. 1, and FIG. 3 is a characteristic diagram of the acceleration control of FIG.
[0030]
The vehicle acceleration control device according to the present embodiment is configured as shown in FIG.
[0031]
For example, the instantaneous command acceleration Gref (t) output from a higher-level device (not shown) formed by the following control ECU similar to the following control ECU 1 shown in FIG. It is given to a command vehicle speed calculation section 4a of the controller 4 and a throttle opening map section 4c of the command throttle opening output section 4b.
[0032]
Incidentally, the acceleration controller 4 is formed by a microcomputer.
[0033]
The command vehicle speed calculating unit 4a forms a command vehicle speed calculating means, and calculates the command vehicle speed Vref (t) by integrating the command acceleration Gref (t).
[0034]
Further, the command throttle opening output section 4b forms a command throttle opening output section, and the throttle opening map section 4c outputs, as data of the vehicle kinetic characteristics, measurement results of acceleration and vehicle speed at each opening of the throttle. For example, data indicating the relationship between the commanded acceleration, the commanded vehicle speed, and the opening degree of the throttle, which are obtained in advance, are held.
[0035]
This data may have any structure, but is preferably three-dimensional map data. The three-dimensional map data is formed in a structure as shown in FIG. The command vehicle speed Vref, the command acceleration Gref, and the throttle opening degree θmap are provided, and the corresponding throttle opening degree θmap is easily derived from the respective values of the command vehicle speed Vref and the command acceleration Gref.
[0036]
The throttle opening θmap is an output of the throttle opening map unit 4c having characteristics of the vehicle motion to be controlled.
[0037]
If the instantaneous throttle opening degree θmap derived from the map unit 4c is a map output θmap (t), compensation of the error, improvement of robust stability against external force, and the like are unnecessary, that is, ideal. When traveling on a flat road under typical conditions, the map output θmap (t) is used as the instantaneous command throttle opening θ (t), and the command throttle opening θ (t) is used as the command throttle opening θ (t). The output from the degree output unit 4b is applied to a vehicle motion system 5 corresponding to the vehicle motion system 3 in FIG.
[0038]
Then, the throttle opening of the vehicle motion system 5 is controlled by the command throttle opening θ (t) to feed-forward control the vehicle acceleration.
[0039]
With this feedforward control, even if the vehicle moves nonlinearly with respect to the throttle opening, the actual acceleration is controlled with good responsiveness to the commanded acceleration, and the responsiveness of the actual acceleration to the commanded acceleration is based on feedback control. It is improved as compared with the case where the control algorithm described above is used, and the acceleration feeling at the time of starting and the like is improved.
[0040]
By the way, an error (data error) based on the error of the map output θmap (t) exists in the command throttle opening θ (t), and there is a road surface gradient or the like on an actual road. In this embodiment, as described below, the feed-forward control is replaced with feedback control, since compensation of the data error and improvement of robust stability against external force during running cannot be achieved. Make corrections.
[0041]
That is, the instantaneously detected vehicle speed V (t) of the vehicle motion system 5 is fed back to the subtractor 4d of the acceleration controller 4, and the subtractor 4d generates an error between the command vehicle speed Vref (t) and the detected vehicle speed V (t). Is the speed deviation e (t), and the speed deviation e (t) is multiplied by K by the constant unit 4e to calculate a feedback output θfb (t) (= K × (Vref (t) −V (t)). This feedback output θfb (t) is supplied to the multiplier 4f.
[0042]
The multiplier 4f multiplies the map output θmap (t) by the feedback output θfb (t), and corrects the map output θmap (t) by θδ (t) (= θmap (t) × θfb (t)). Is calculated and supplied to the adder 4g for correction.
[0043]
The adder 4g adds the correction amount θδ (t) to the map output θmap (t), and outputs the map output corrected by the addition (= θmap (t) × (1 + θδ (t)) to the command throttle opening. It is given to the vehicle motion system 5 as θ (t).
[0044]
In this case, the throttle opening of the vehicle motion system 5 is controlled by adding the correction of the feedback control to the feed forward control, and the control based on the feed forward control is not compensated only by the feed forward control. Compensation for an error of θ (t) (data error), improvement of robust stability against external force, and the like are also achieved.
[0045]
The subtractor 4d, the constant unit 4e, the multiplier 4f, and the adder 4g form a correction unit.
[0046]
By giving the corrected map output to the vehicle motion system 5 as the commanded throttle opening θ (t), for example, a characteristic diagram of the acceleration control shown in FIG. 3 was obtained.
[0047]
In FIG. 3, the horizontal axis represents time, the vertical axis represents acceleration, solid line A represents command acceleration, and solid line B represents actual acceleration.
[0048]
As is clear from the comparison between FIG. 3 and FIG. 5, in the case of the present embodiment, the amount of overshoot and undershoot of the actual acceleration with respect to the commanded acceleration is extremely reduced, and the control result is quickly stabilized.
[0049]
Therefore, the responsiveness to the command acceleration is greatly improved, and the acceleration feeling at the time of starting or the like is significantly improved.
[0050]
Note that the present invention is not limited to the configuration of the above-described embodiment, and various changes other than those described above can be made without departing from the gist of the present invention. A hardware configuration using a circuit or the like may be used, and the data indicating the relationship between the commanded acceleration, the commanded vehicle speed, and the throttle opening may have a data structure other than the three-dimensional map data structure.
[0051]
【The invention's effect】
As described above, according to the first and sixth aspects of the present invention, the actual acceleration is feedforward-controlled based on the commanded acceleration, and even if the vehicle motion shows a non-linear behavior with respect to the throttle opening, the actual acceleration is controlled. Acceleration is controlled with good responsiveness to command acceleration, responsiveness to command acceleration is improved, and acceleration feeling at the time of starting or the like can be improved.
[0052]
According to the second and seventh aspects of the present invention, the feedback control is added to the feedforward control, and the data error of the command throttle opening is not compensated by only the feedforward control. The responsiveness to command acceleration can be further improved, and the acceleration feeling at the time of starting or the like can be further improved.
[0053]
According to the third and eighth aspects of the present invention, the product of the command throttle opening and the feedback control output is calculated as a correction amount, and the correction amount is added to correct the command throttle opening. A practical configuration for performing control correction can be provided.
[0054]
According to the fourth and ninth aspects of the present invention, the command throttle opening determined by the command vehicle speed and the command acceleration can be easily derived as a so-called map output.
[0055]
Furthermore, according to the fifth and tenth aspects of the present invention, it is possible to provide a practical configuration when applied to acceleration control of a vehicle having a follow-up traveling system configuration.
[Brief description of the drawings]
FIG. 1 is a block diagram of one embodiment of the present invention.
FIG. 2 is a data structure diagram of a throttle opening map section of FIG. 1;
FIG. 3 is a characteristic diagram of the acceleration control of FIG. 1;
FIG. 4 is a block diagram of acceleration control of feedback control.
FIG. 5 is a characteristic diagram of the acceleration control of FIG. 4;
[Explanation of symbols]
4 Acceleration controller 4a Command vehicle speed calculation unit (command vehicle speed calculation means)
4b Command throttle opening output section (command throttle opening output means)
4c Throttle opening map unit 4d Subtractor 4e Constant unit 4f Multiplier 4g Adder

Claims (10)

Command vehicle speed calculating means for calculating the command vehicle speed by integrating the command acceleration;
Data indicating the relationship between the command acceleration, the command vehicle speed, and the opening degree of the throttle of the vehicle motion system is held as data of vehicle motion characteristics, and the throttle opening determined by the command acceleration and the command vehicle speed is determined from the held data. Command throttle opening output means derived as a command throttle opening,
An acceleration control device for a vehicle, wherein the throttle opening is controlled by the command throttle opening to perform feedforward control on the acceleration. The vehicle acceleration control device according to claim 1,
An acceleration control device for a vehicle, comprising: a correction unit configured to correct the command throttle opening by a feedback control output proportional to a difference between the command vehicle speed and the detected vehicle speed. The correction means calculates a product of the command throttle opening and the feedback control output as a correction amount, and corrects the command throttle opening by adding the correction amount to the command throttle opening. The vehicle acceleration control device according to claim 2. The data indicating the relationship between the commanded acceleration, the commanded vehicle speed, and the throttle opening is three-dimensional map data of the commanded acceleration, the commanded vehicle speed, and the throttle opening. 4. The vehicle acceleration control device according to any one of claims 3 to 3. The vehicle acceleration control device according to any one of claims 1 to 4, wherein the command acceleration is derived from a calculation of an inter-vehicle distance control. Calculates the command vehicle speed by integrating the command acceleration,
From the data indicating the relationship between the command acceleration, the command vehicle speed, and the opening of the throttle of the vehicle motion system held as data of vehicle motion characteristics, the throttle opening determined by the command acceleration and the command vehicle speed is used as the command throttle opening. Derived as
An acceleration control method for a vehicle, wherein an acceleration of the vehicle is controlled by feedforward control by controlling the opening of the throttle according to the command throttle opening. The vehicle acceleration control method according to claim 6,
A vehicle acceleration control method, wherein the command throttle opening is corrected by a feedback control output proportional to a difference between the command vehicle speed and the detected vehicle speed. 8. The method according to claim 7, wherein a product of the command throttle opening and the feedback control output is calculated as a correction amount, and the command throttle opening is corrected by adding the correction amount to the command throttle opening. The vehicle acceleration control method according to any one of the preceding claims. 7. The data indicating the relationship between the commanded acceleration, the commanded vehicle speed, and the throttle opening is three-dimensional map data of the commanded acceleration, the commanded vehicle speed, and the throttle opening. 9. The vehicle acceleration control method according to any one of claims 8 to 8. The vehicle acceleration control method according to any one of claims 6 to 9, wherein the command acceleration is derived from a calculation of an inter-vehicle distance control.

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