Vehicle movement dynamics control system

• US 5,455,770 A
• Filed: 02/18/1994
• Issued: 10/03/1995
• Est. Priority Date: 02/19/1993
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hadeler, Ralf, Heess, Gerhard, Erban, Andreas, Mergenthaler, Rolf-Hermann
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/198,695
• Time in Patent Office: 592 Days
• Field of Search: 364/426.01, 364/426.02, 364/426.04, 364/424.05, 364/431.12, 364/567, 303/93, 303/100, 303/102, 303/104, 303/113.02, 180/197, 180/170
• US Class Current: 701/70
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• 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 8/17552 responsive to the tire sideslip angle or the vehicle body slip angle

Abstract

A brake controller is connected downstream of a primary vehicle dynamics computer and has a channel for controlling the yaw velocity at a desired value, and a channel for limiting the sideslip angle. The computer prescribes the desired value and the limit value, and determines which channel is effective on the basis of the driving situation. The two channels generate a control signal which is routed via a control amplifier having a proportional component and a differential component. An actuating signal which is used to input braking pressure at the wheel brakes is formed from the resulting signal components, the instantaneous driving situation being assigned in both cases to one of a plurality of classes, and this assignment being co-used to determine the wheels at which braking pressure is input.

Claims

1. Method for stabilizing movement of a vehicle, said method comprising the following steps:

measuring wheel speeds v_Ri, yaw velocity w, front axle steering angle δ

_v, and optionally at least one of longitudinal vehicle acceleration B_x and traverse vehicle acceleration B_y,

forming a longitudinal vehicle velocity V_x from said wheel speeds V_Ri,

forming a desired yaw velocity w_s from at least said front axle steering angle δ

_v,

determining a utilized coefficient of friction μ

_A from at least one of said wheel speeds V_Ri and said longitudinal vehicle acceleration B_x,

estimating a sideslip angle β

from at least one of said wheel speeds V_Ri and said transverse acceleration B_y,

determining whether said sideslip angle β

exhibits a positive gradient or a negative gradient,

determining a first sideslip angle limit value β

_g1 from said utilized coefficient of friction β

_A and said longitudinal vehicle velocity V_x,

determining a second sideslip angle limit value β

₂ from said first sideslip angle limit value β

_g1, said limit value β

_g2 being greater than said limit value β

_g1,

comparing said estimated sideslip angle β

with said first limit value β

_g1,

effecting a normal control mode when β

is less than β

_g1 or when β

is greater than β

_g1 but less than B_g2 and said gradient is negative,

varying brake pressure so that w approaches w_s when said normal control mode is effected,

effecting a special control mode when β

is greater than β

_g1 and said gradient is positive or when β

is greater than β

_g2, and

varying brake pressure so that β

is limited to β

_g1 when said special control mode is effected.

2. Method as in claim 1 wherein said first sideslip angle limit value β

_g1 is determined from a stored characteristic map having as arguments longitudinal vehicle velocity V_x and utilized coefficient of friction μ

_A.

3. Method as in claim 2 wherein said characteristic map provides a raw value β

_R based on said arguments, said value β

_g1 being determined by filtering β

_R.

4. Method as in claim 1 wherein said second sideslip unit value β

_g2 is determined according to P_Krit β

_g1, where P_Krit >

1.

5. Method as in claim 1 wherein said normal control mode is effected whenever V_x falls below a predetermined value.

6. Method as in claim 1 wherein a return is made from special control mode to normal control mode when β

is less than β

_g2 and W.W_s <

0.

7. Method as in claim 1 wherein a return is made from special control mode to normal control mode when β

is less than β

_g2 and the absolute value of w is less than the absolute value of the product of w_s and a control parameter.

8. Method as in claim 1 further comprising

determining whether said yaw velocity w exhibits a positive gradient or a negative gradient,

comparing said yaw velocity w to said desired yaw velocity w_s, and

building up brake pressure when w exhibits a positive gradient and exceeds w_s by a predetermined value.

9. Method as in claim 1 further comprising building up brake pressure when the sideslip angle β

exhibits a positive gradient and β

exceeds a predetermined value.