JP2006103510A - Vehicular yaw rate estimating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an accurate estimating yaw rate corresponding to a friction coefficient of a road surface by adding minimum soft ware and processing time while using conventional a linear response function, in a vehicular yaw rate estimating device comprising a steering angle detector detecting a steering angle, a parameter setting means setting a parameter of the linear response function established between the steering angle and a yaw rate so as to correspond to the road surface of a high friction coefficient about each set vehicular speed different from each other, and a computing means computing an estimating yaw rate on the basis of the linear response function using the parameter set by the parameter setting means and the steering angle detected by the steering angle detector. <P>SOLUTION: A phase considering steering angle causing phase delay to a detection value of the steering angle detector 1 is inputted from a low pass filter 4 to the computing means 3. A phase parameter of the low pass filter 4 is set according to a friction coefficient by the phase parameter setting means 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a steering angle detector for detecting a steering angle and a parameter for setting a parameter of a linear response function established between the steering angle and the yaw rate corresponding to a road surface having a high friction coefficient for each of a plurality of different set vehicle speeds. Vehicle yaw rate estimation comprising: setting means; and calculation means for calculating an estimated yaw rate based on the linear response function using the parameter set by the parameter setting means and the steering angle detected by the steering angle detector Relates to the device.

Such a yaw rate estimation apparatus is already known, for example, from Patent Document 1.
JP-A-6-111185

  However, in the conventional yaw rate estimation device, the parameter of the linear response function is set corresponding to a road surface with a high friction coefficient, and when the road surface becomes a road surface with a low friction coefficient such as a snow road, The linear response function cannot be used as it is, and the yaw rate is approximately obtained by multiplying the yaw rate obtained based on the linear response function by a parameter corresponding to the friction coefficient.

  By the way, if the friction coefficient of the road surface becomes small, the response gain of the yaw rate with respect to the steering angle becomes small and the time delay phase becomes large. By changing the steering angle / yaw rate response characteristic according to the change of the friction coefficient, It would be possible to estimate a more accurate yaw rate according to the friction coefficient.

  The present invention has been made in view of such circumstances, and is more accurate according to the friction coefficient of the road surface by adding the minimum processing time by adding the minimum software while utilizing the conventional linear response function. It is an object of the present invention to provide a vehicle yaw rate estimation device capable of obtaining an estimated yaw rate.

  In order to achieve the above object, the present invention provides a steering angle detector for detecting a steering angle, and a parameter of a linear response function established between the steering angle and the yaw rate, with a high friction coefficient for each of a plurality of different set vehicle speeds. Parameter setting means set corresponding to the road surface, and calculation for calculating the estimated yaw rate based on the linear response function using the parameter set by the parameter setting means and the steering angle detected by the steering angle detector In the vehicle yaw rate estimation device comprising: a low-pass filter that causes the detected value of the steering angle detector to have a phase delay and that is input to the calculation means; and a friction coefficient estimation means that estimates a friction coefficient of the ground contact surface of the vehicle And phase parameter setting means for setting the phase parameter of the low-pass filter in accordance with the friction coefficient estimated by the friction coefficient estimation means Characterized in that it contains.

  According to such a configuration of the invention, the phase-considered steering angle having a phase delay by the low-pass filter using the phase parameter set according to the estimated friction coefficient of the road surface is input to the calculation means. Since the yaw rate is calculated by the calculation means so that the steering angle / yaw rate response characteristics are changed according to the change of the friction coefficient, it is possible to obtain a more accurate estimated yaw rate according to the friction coefficient of the road surface, and the conventional yaw rate Only a low-pass filter is added to the estimation device, and a minimum processing time can be added by adding a minimum amount of software.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  FIG. 1 is a block diagram showing the configuration of the apparatus of the present invention, and FIG. 2 is a diagram showing a phase parameter setting map according to the friction coefficient.

  First, in FIG. 1, this yaw rate estimation apparatus includes a steering angle detector 1 that detects a steering angle δ at which a linear response function is established with respect to a yaw rate, and a plurality of different set vehicle speeds with different parameters of the linear response function. Parameter setting means 2 for setting corresponding to the road surface having a high friction coefficient, calculation means 3 for calculating the estimated yaw rate γ using the linear response function using the parameters set by the parameter setting means 2, A low-pass filter 4 that gives a detected phase value to the detected value of the steering angle detector 1 and inputs it to the calculation means 3, a friction coefficient estimation means 5 that estimates the friction coefficient of the ground contact surface of the vehicle, and the friction coefficient estimation means 5 Phase parameter setting means 6 for setting the phase parameter of the low-pass filter 4 according to the estimated friction coefficient.

  By the way, in the calculation means 3, if the phase-considered steering angle δA is input from the low-pass filter 4, the linear response function S can be assumed using the Z transformation as follows:

S = γ / δA = (B0 + B1 · Z ⁻¹ ) / (A0 + A1 · Z ⁻¹ + A2 / Z ⁻² )
The parameters A0, A1, A2; B0, B1 of the linear response function S are set by the parameter setting means 2 according to the vehicle speed V inputted from the vehicle speed detection means 7, and the parameter setting means 2 When setting the parameters A0, A1, A2; B0, B1, the parameters A0, A1, A2; B0, B1 corresponding to the road surface having a high friction coefficient are set in advance for each of a plurality of predetermined different vehicle speeds. deep.

  In the phase parameter setting means 6, the phase parameter φ (0 <φ <1) is set according to the friction coefficient μ of the road surface as shown in FIG. 2, and the friction coefficient μ estimated by the friction coefficient estimation means 5. Is input from the phase parameter setting means 6 to the low-pass filter 4.

  Thus, in the low-pass filter 4, the phase-considered steering angle δA is obtained by {δA = φ · δ (n) + (1−φ) · δA (n−1)} by the following equation using the phase parameter φ. By this calculation, the phase-considered steering angle δA having a phase delay is input from the low-pass filter 4 to the calculation means 3.

  Thus, by using the phase parameter φ set according to the estimated friction coefficient μ of the road surface, the phase-considered steering angle δA having a phase delay by the low-pass filter 4 is input to the calculation means 3, thereby calculating The means 3 calculates the yaw rate γ by changing the steering angle / yaw rate response characteristics in accordance with the change in the friction coefficient μ.

  Accordingly, it is possible to obtain a more accurate estimated yaw rate γ according to the road surface friction coefficient μ by the calculation means 3.

  In addition, the device of the present invention only adds the low-pass filter 4 to the conventional yaw rate estimation device, and the minimum processing by adding the minimum software while utilizing the conventional linear response function to the conventional yaw rate estimation device. By adding time, a more accurate estimated yaw rate γ according to the friction coefficient μ of the road surface can be obtained.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

It is a block diagram which shows the structure of this invention apparatus. It is a figure which shows the setting map of the phase parameter according to a friction coefficient.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steering angle detector 2 ... Parameter setting means 3 ... Calculation means 4 ... Low pass filter 5 ... Friction coefficient estimation means 6 ... Phase parameter setting means delta ... Steering angle A0 , A1, A2; B0, B1 ... Parameter φ ... Phase parameter

Claims (1)

  The steering angle detector (1) for detecting the steering angle (δ) and the parameters (A0, A1, A2; B0, B1) of the linear response function established between the steering angle and the yaw rate are set at a plurality of different set vehicle speeds. Parameter setting means (2) set corresponding to the road surface having a high friction coefficient, and the linear response using the parameters (A0, A1, A2; B0, B1) set by the parameter setting means (2) In the vehicle yaw rate estimation device, comprising: a function and a calculation means (3) for calculating an estimated yaw rate (γ) based on the steering angle (δ) detected by the steering angle detector (1). A low-pass filter (4) for giving a phase lag to the detected value of (1) and inputting it to the computing means (3); a friction coefficient estimating means (5) for estimating the friction coefficient of the ground contact surface of the vehicle; Coefficient estimation means Yaw rate estimation apparatus for a vehicle which comprises a phase parameter setting means (6) for setting the phase parameters (phi) of the low-pass filter in accordance with the friction coefficient estimated by 5) (4).

Images