Stability control system for automotive vehicle

A stability control system for a vehicle for controlling braking force that is applied independently to respective from and rear wheels to control a slip and a spin of said vehicle, said stability control system comprising:

• state variable detecting means for detecting running state variables including a yaw rate of said vehicle;
• parameter determining means for determining an estimated slip angle of a slip occurring in said vehicle, a target yaw rate of said vehicle and a target slip angle of said vehicle on the basis of said running state variables;
• slip angle controlling means for controlling said braking force so as thereby to bring said estimated slip angle into said target slip angle when a slip angle difference between said estimated slip angle and said target slip angle exceeds a threshold slip angle for starting braking control;
• and
• changing means for, when a change rate of a yaw rate difference between said yaw rate and said target yaw rate exceeds a specified change rate, judging which is a main cause, due to which said change rate of said yaw rate difference exceeds said specified change rate, between said yaw rate and said target yaw rate exceeds a predetermined rate between a change in said yaw rate and a change in said target yaw rate and changing said threshold slip angle according to said main cause.

A stability control system for a vehicle for controlling braking force that is applied independently to respective front and rear wheels to control a slip and a spin of said vehicle, said stability control system comprising:

• state variable detecting means for detecting running state variables of said vehicle;
• parameters determining means for determining an estimated slip angle of a slip occurring in said vehicle and a target slip angle of said vehicle on the basis of said running state variables;
• slip angle controlling means for controlling said braking force so as thereby to bring said estimated slip angle into said target slip angle when a slip angle difference between said estimated slip angle and said target slip angle exceeds a threshold slip angle for starting braking control;
• and
• changing means for, when a change rate of said slip angle difference exceeds a specified change rate, judging which is a main cause, due to which said change rate of said slip angle difference exceeds said specified change rate, between a change in said estimated slip angle and a change in said target slip angle and changing at least one of said threshold slip angle and said braking force applied through said braking control according to said main cause.

A system of driving stability control for a vehicle when controls braking force applied independently to respective front and rear wheels to control a slip and a spin of said vehicle, said system of driving stability control comprising:

• a master cylinder operative to generate hydraulic pressure according to operations of a brake pedal of said vehicle;
• a pressure intensifier operative to intensify said hydraulic pressure;
• a hydraulic pressure control unit operative to distribute said hydraulic pressure to brake units for front and rear, right and left wheels, respectively;
• a speed sensor operative to detect a running speed of said vehicle;
• a yaw rate sensor operative to detect a yaw rate of said vehicle;
• a lateral acceleration sensor operative to detect a lateral acceleration of said vehicle;
• a braking force control unit operative to control said hydraulic pressure control unit on the basis of said running speed, said yaw rate and said lateral acceleration so as to control said braking force applied to each said wheel;
• wherein said braking force control unit determines an estimated slip angle of a slip occurring in said vehicle, a target yaw rate of said vehicle and a target slip angle of said vehicle on the basis of said running speed, said yaw rate and said lateral acceleration, controls said hydraulic pressure control unit so as to bring said yaw rate into said target yaw rate when a yaw rate difference between said yaw rate and said target yaw rate exceeds a threshold yaw rate for starting braking control based on yaw rate, controls said hydraulic pressure control unit so as to bring said estimated slip angle into said target slip angle when a slip angle difference between said estimated slip angle and said target slip angle exceeds a threshold slip angle for starting braking control based on slip angle, judges which is a main cause, due to which said yaw rate difference exceeds said threshold yaw rate, between a change in said yaw rate and a change in said target yaw rate when said yaw rate difference exceeds said threshold yaw rate, and then changes at least one of said threshold slip angel and said braking force applied through said braking control based on yaw rate according to said main cause.

A system of driving stability control for a vehicle which controls braking force applied independently to respective front and rear wheels to control a slip and a spin of said vehicle, said system of driving stability control comprising:

• a master cylinder operative to generate hydraulic pressure according to operations of a brake pedal of said vehicle;
• a pressure intensifier operative to intensify said hydraulic pressure;
• a hydraulic pressure control unit operative to distribute said hydraulic pressure to brake units for front and rear, right and left wheels, respectively;
• a speed sensor operative to detect a running speed of said vehicle;
• a yaw rate sensor operative to detect a yaw rate of said vehicle;
• a lateral acceleration sensor operative to detect a lateral acceleration of said vehicle;
• and
• a braking force control unit operative to control said hydraulic pressure control unit on the basis of said running speed, said yaw rate and said lateral acceleration so as to control said braking force applied to each said wheel;
• wherein said braking force control unit determines an estimated slip angle of a slip occurring in said vehicle, a target yaw rate of said vehicle and a target slip angle of said vehicle on the basis of said running speed, said yaw rate and said lateral acceleration, controls said braking force so as thereby to bring said estimated slip angle into said target slip angle when a slip angle difference between said estimated slip angle and said target slip angle exceeds a threshold slip angle for starting braking control, judging which is a main cause, due to which said change rate of said yaw rate difference exceeds said specified change rate, between said yaw rate and said target yaw rate exceeds a predetermined rate between a change in said yaw rate and a change in said target yaw rate when a change rate of a yaw rate difference between said yaw rate and said target yaw rate exceeds a specified change rate, and than changes said threshold slip angle according to said main cause.

A system of driving stability control for a vehicle which controls braking force applied independently to respective front and rear wheels to control a slip and a spin of said vehicle, said system of driving stability control comprising:

• a master cylinder operative to generate hydraulic pressure according to operations of a brake pedal of said vehicle;
• a pressure intensifier operative to intensify said hydraulic pressure;
• a hydraulic pressure control unit operative to distribute said hydraulic pressure to brake units for front and rear, right and left wheels, respectively;
• a speed sensor operative to detect a running speed of said vehicle;
• a yaw rate sensor operative to detect a yaw rate of said vehicle;
• a lateral acceleration sensor operative to detect a lateral acceleration of said vehicle;
• and
• a braking force control unit operative to control said hydraulic pressure control unit on the basis of said running speed, said yaw rate and said lateral acceleration so as to control said braking force applied to each said wheel;
• wherein said braking force control unit determines an estimated slip angle of a slip occurring in said vehicle and a target slip angle of said vehicle on the basis of said running speed, said yaw rate and said lateral acceleration, controls said braking force so as thereby to bring said estimated slip angle into said target slip angle when a slip angle difference between said estimated slip angle and said target slip angle exceeds a threshold slip angle for starting braking control, judges which is a main cause, due to which said change rate of said slip angle difference exceeds a specified change rate, between a change in said estimated slip angle and a change in said target slip angle when a change rate of said slip angle difference exceeds said specified change rate, and then changes at least one of said threshold slip angle and said braking force applied through said braking control according to said main cause.