Method for improving the controllabilty of motor vehicles

• US 5,668,724 A
• Filed: 09/11/1995
• Issued: 09/16/1997
• Est. Priority Date: 09/28/1990
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kost, Friedrich, Ruf, Wolf-Dieter, Hartmann, Uwe, Erhardt, Rainer, Van Zanten, Anton, Ehret, Thomas, Busch, Gerd, Weiss, Karl-Josef
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/526,280
• Time in Patent Office: 736 Days
• Field of Search: 364/426.01, 364/426.02, 364/426.03, 364/424.05, 364/424.01, 180/79.1, 180/140, 180/197, 180/142, 303/147, 303/113.4, 303/163, 303/165, 303/185, 303/198, 303/146, 303/9.62, 303/139, 303/145, 303/174, 303/140, 280/707, 395/900, 395/905, 73/510, 73/514.39
• US Class Current: 701/80
• CPC Class Codes: B60T 2270/86 Optimizing braking by using ESP vehicle or tire model
• 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

Abstract

A method for improving the controllability of motor vehicles during braking wherein desired slip values are determined and adjusted with the aid of a wheel slip controller. According to the method, the following are measured: the yaw rate ψ, the steering angle δ, the wheel speeds V_Ri, the inlet pressure P_inlet or wheel brake pressure P_i, and, if required, the engine speed and the throttle valve angle. The following variables are estimated using the measured values: the longitudinal vehicle speed V_X, the longitudinal vehicle acceleration V_X, the wheel slip values λ_i, the braking forces F_Bi, the tire forces F_Ri, and the transverse speed V_Y. Desired slip values λ_i * are then determined from these measured and estimated variables with the aid of a simple vehicle model and supplied to the slip controller to control the vehicle wheel brake pressure.

Claims

1. Method for improving the controllability of a wheeled vehicle during braking of wheels of the vehicle, comprising the steps of:

measuring yawing speed ψ

, wheel speeds V_Ri, steering angle δ and

at least one of inlet pressure P_inlet and wheel brake cylinder pressures P_i, where i represents a respective wheel and equals 1, 2, 3 or 4;

supplying these measured variables ψ

, V_Ri, δ

, and at least one of P_inlet and wheel brake pressures P_i to a slip controller and, from these measured variables, determining longitudinal vehicle speed V_X, longitudinal vehicle acceleration V_X, respective wheel slip values λ

_i, and braking forces F_Bi ;

supplying the determined variables F_Bi, λ

_i and V_X to an observer which, with the aid of the measured variables λ and

δ

, determines tire forces F_Ri and a vehicle transverse speed V_Y from these variables;

supplying the determined variables V_X, V_X, λ

_i, F_Ri and V_Y and the measured variables ψ and

δ

to a vehicle controller;

in the vehicle controller, and with the aid of a simple vehicle model and the determined and measured variables supplied to the vehicle controller, determining desired slip values λ

_i^* that effect a better controllability of the vehicle for the respective wheels;

supplying the desired slip values λ

_i^* to the slip controller; and

via the slip controller, controlling the respective wheel brake cylinder pressures P_i at the wheel brakes to achieve the desired slip values λ

_i^* at the respective wheels.

2. Method according to claim 1, wherein said step of supplying the desired slip values λ

_i^* to the slip controller includes feeding the desired slip values λ

_i^* to an antiblockrive slip controller which generates its own desired slip values, and, superimposing a deviation between one of said desired slip values from the other on said desired slip values generated in the antiblock/drive slip controller.