BRAKE CONTROL SYSTEM


  1. SYSTEM CONTROL


    1. If the driver suddenly applies the brakes on a road surface with a considerable difference in friction coefficient between the right and left wheels, the difference in the brake force between the right and left wheels will cause the vehicle posture to become unstable and create a yaw moment. In this state, the skid control ECU assembly controls the VSC to stabilize the vehicle posture.

    2. The skid control ECU assembly effects cooperative control with the power steering ECU assembly to provide steering torque assist, which facilitates the driver's steering maneuvers to stabilize the vehicle posture.

      A01R1V8C01
      *a Moment Resulting from Difference in Brake Force between Left and Right Wheels - -
      B00807K Brake Force B00806U Steering Torque Assist Direction
      B0055BN Slippery Surface - -

    3. If the driver suddenly starts off or accelerates on a road surface with a considerable difference in friction coefficient between the right and left wheels, the slippage of a drive wheel will cause the vehicle posture to become unstable and negatively affect its acceleration performance. In this state, the skid control ECU assembly causes the TRC to control the hydraulic brake of the slipping drive wheel, and makes a request to the hybrid vehicle control ECU assembly to effect motive force control.

    4. The skid control ECU assembly effects cooperative control with the power steering ECU assembly to provide steering torque assist, which facilitates the driver's steering maneuvers to stabilize the vehicle posture.

      A01R2BVC01
      *a Moment Resulting from Difference in Brake Force between Left and Right Wheels - -
      B00807K Drive Force B00806U Steering Torque Assist Direction
      B0055BN Slippery Surface - -

    5. When the skid control ECU assembly determines a front wheel skid tendency, it controls the VSC to dampen the front wheel skid, and makes a request to the hybrid vehicle control ECU assembly to effect motive force control.

    6. The skid control ECU assembly effects cooperative control with the power steering ECU assembly to provide steering torque assist, which controls the driver's steering maneuvers to stabilize the vehicle posture. Steering torque assist is provided to inform the driver of a front wheel skid, and in order to prevent the driver from excessively turning the steering wheel, the skid control ECU assembly increases the resistance to counter the driver's steering effort.

      A01R297C02
      *a Moment of Force to Restrict Front Wheel Skid *b Brake Force
      *c Steering Torque Assist Direction (to Inform of Front Wheel Skid) *d Steering Torque Assist Direction (to Prevent Excessive Turning)

    7. When the skid control ECU assembly determines a rear wheel skid tendency, it controls the VSC to dampen the rear wheel skid and makes a request to the hybrid vehicle control ECU assembly to effect motive force control.

    8. The skid control ECU assembly effects cooperative control with the power steering ECU assembly to provide steering torque assist, which facilitates the driver's steering maneuvers in the appropriate direction to correct the rear wheel skid.

      A01R2GJC02
      *a Moment of Force to Restrict Rear Wheel Skid *b Brake Force
      *c Rear Wheel Skid Moment *d Steering Torque Assist Direction