Brake fluid pressure control apparatus for vehicle

A brake fluid pressure control apparatus for executing rollover prevention control, wherein a brake is applied to at least one wheel of a vehicle when a rollover tendency of the vehicle is detected from a rollover detection parameter being greater than a parameter threshold value while the vehicle is turning, the brake fluid pressure control apparatus comprising:

• a parameter acquisition unit configured to acquire the rollover detection parameter;
• a parameter calculation unit configured to set the parameter threshold value,
• wherein the parameter acquisition unit acquires a roll angle of the vehicle as the rollover detection parameter, and
• wherein the parameter calculation unit calculates a threshold calculation roll rate, which is a rate of change of the roll angle of the vehicle, and sets the parameter threshold value to a smaller value with an increase in the threshold calculation roll rate;
• and
• a steering maneuver determination unit configured to determine whether or not an abrupt steering maneuver is made,
• wherein the parameter calculation unit is configured to calculate a composition roll rate as the threshold calculation roll rate, by combining at a predetermined weight assignment ratio a first roll rate which is a rate of change of a first roll angle equivalent to an actual roll angle with a second roll rate which is a rate of change of a second roll angle obtained using a parameter which changes with a phase earlier than the first roll angle, and
• wherein the parameter calculation unit calculates the composition roll rate by changing the weight assignment ratio such that a weight of the second roll rate is higher when the steering maneuver determination unit determines that an abrupt steering maneuver is made than when the steering maneuver determination unit determines that the abrupt steering maneuver is not made.