Method of obtaining the yawing velocity and/or transverse velocity of a vehicle

• US 5,311,431 A
• Filed: 07/01/1992
• Issued: 05/10/1994
• Est. Priority Date: 07/03/1991
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Bertram, Thorsten, Cao, Chi-Thuan
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/906,292
• Time in Patent Office: 678 Days
• Field of Search: 364/565, 364/566, 364/424.05, 364/426.02, 364/426.03, 180/79.1, 180/140-142, 180/197, 280/91, 303/95, 303/100, 303/103
• US Class Current: 701/72
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 2250/03 Vehicle yaw rate
• CPC Class Codes: B60T 2260/022 Rear-wheel steering; Four-wheel steering
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 40/103 Side slip angle of vehicle body
• CPC Class Codes: B60W 40/11 Pitch movement
• CPC Class Codes: B60W 40/112 Roll movement
• CPC Class Codes: B60W 40/114 Yaw movement
• CPC Class Codes: B62D 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

A method for obtaining the yawing velocity ω and the transverse velocity v_y of a vehicle so that these values can be employed, for example, in regulating the vehicle system, with the values being determined with the aid of simple sensors. Measured values are obtained for the transverse acceleration a_y and the steering angles δ of the two axles, and the yawing velocity ω and the vehicle'"'"'s transverse velocity v_y are estimated therefrom in a state estimator.

Claims

1. In a method of controlling a motor driven wheeled vehicle having front and rear axles and including the steps of obtaining values for at least one of the yawing velocity ω

and the transverse velocity v_y of the vehicle, and using the obtained values for at least one of the yawing velocity ω and

the transverse velocity v_y to control a driving dynamic of the vehicle;

the improvement wherein said step of obtaining comprises;

measuring and providing signals corresponding to the transverse acceleration a_y, the front wheel drive angle δ

_v, and any rear-wheel drive angle δ

_h of the vehicle;

forming a data vector

space="preserve" listing-type="equation">m.sup.r (k-1)-[a.sub.y (k-2)a.sub.y (k-3)|δ

.sub.v (k-1)δ

.sub.v (k-2)δ

.sub.v (k-3)|δ

.sub.h (k-1)δ

.sub.h (k-2)δ

.sub.h (k-3)].sup.r

from the three measured values a_y, δ

_v and δ

_h, with k, (k-1), (k-2), and (k-3) representing times of measurements;

multiplying the data vector m^r (k-1) with the estimated value of a parameter vector p(k-1) to determine an estimated value for the transverse acceleration a_y (k);

recursively calculating the estimated value of a parameter vector p(k) using an estimation algorithm from the previously determined estimated value p(k-1) and an error value e(k)=a_y (k)-a_y (k);

multiplying the matrix M*(k-1) of the data vector m^r (k-1) with the matrix p* (k) of the parameter vector p(k) to determine a state vector x(k)=[ω

(k) v_y (k)]; and

,

determining at least one of the yawing velocity ω

(k) and the transverse velocity v_y (k) of the vehicle from the state vector.

2. A method according to claim 1, wherein said step of calculating the estimated value of the parameter vector p(k) includes obtaining the estimated value of the parameter vector by the following equation:

space="preserve" listing-type="equation">p(k)-p(k-1)+r(k)·

e(k)

where, with a stochastic approximation, r(k) is selected as follows;

##EQU5##

3. A method according to claim 2, wherein said step of using includes measuring the longitudinal velocity v_x of the vehicle, and determining the side slip angle β

=v_y /v_x of the vehicle from the determined transverse velocity v_y and the measured longitudinal velocity v_x.

4. A method according to claim 3, wherein said step of using further includes calculating the slip angles α

_v and α

_h of the respective front and rear axles according to the following equations;

##EQU6## where l_v and l_h are the respective distances of the front and rear axles from the center of gravity of the vehicle.

5. A method according to claim 4, wherein said step of using further includes determining the lateral stability forces F_yv and F_yh, of the wheels of the respective front and rear axles according to the following equations:

##EQU7## where m_f is the vehicle mass, p_u11 and p_u21 are the associated terms of the matrix of the parameter vector, and α

_v (k) and α

_h (k) are the slip angles associated with the respective front and rear axles.

6. A method according to claim 1, wherein said step of using includes measuring the longitudinal velocity v_x of the vehicle, and determining the side slip angle β

=v_y /v_x of the vehicle from the determined transverse velocity v_y and the measured longitudinal velocity v_x.

7. A method according to claim 6, wherein said step of using further includes:

measuring the longitudinal velocity v_x of the vehicle, and calculating the slip angles α

_v and α

_h of the respective front and rear axles according to the following equations;

##EQU8## where l_v and l_h are the respective distances of the front and rear axles from the center of gravity of the vehicle.

8. A method according to claim 1, wherein said step of using further includes calculating the slip angles α

_v and α

_h of the respective front and rear axles according to the following equations;

##EQU9## where v_x is the longitudinal velocity of the vehicle, and l_v and l_h are the respective distances of the front and rear axles from the center of gravity of the vehicle.

9. A method according to claim 8, wherein said step of using further includes:

determining the lateral stability forces F_yv and F_yh, of the wheels of the respective front and rear axles according to the following equations;

##EQU10## where m_f is the vehicle mass, p_u11 and p_u21 are the associated terms of the matrix of the parameter vector, and α

_v (k) and α

_h (k) are the slip angles associated with the respective front and rear axles.