Vehicle motion control apparatus

A vehicle motion control apparatus comprising:

• wheel brake cylinders operatively associated with wheels of a vehicle, respectively;
• a master cylinder connected to said wheel brake cylinders through a dual hydraulic circuit with a pair of wheel brake cylinders included in each hydraulic circuit, said master cylinder discharging a hydraulic braking pressure into each hydraulic circuit in response to operation of a brake pedal;
• hydraulic pressure regulating means disposed between said master cylinder and said pair of wheel brake cylinders, for regulating the hydraulic braking pressure supplied into each of said pair of wheel brake cylinders;
• vehicle state monitor means for monitoring state variable of said vehicle;
• desired value setting means for setting a desired value provided for a wheel brake cylinder operatively associated with a wheel to be controlled, out of said pair of wheel brake cylinders included in each hydraulic circuit;
• desired value modifying means for modifying the desired value set by said desired value setting means to provide a modified desired value for at least one wheel brake cylinder out of said pair of wheel brake cylinders including said wheel brake cylinder operatively associated with said wheel to be controlled, at least in response to operation of said brake pedal;
• and
• control means for controlling said pressure regulating means in response to a result of comparison between the desired value set by said desired value setting means and the state variable monitored by said vehicle state monitor means, to regulate the hydraulic braking pressure in said wheel brake cylinder operatively associated with said wheel to be controlled, said control means controlling said pressure regulating means in response to a result of comparison between the modified desired value provided by said desired value modifying means and the state variable monitored by said vehicle state monitor means, and said control means controlling said pressure regulating means to reaulate the hydraulic braking pressure in said at least one wheel brake cylinder included in said hydraulic circuit including said wheel brake cylinder operatively associated with said wheel to be controlled when said brake pedal is operated to discharge the hydraulic braking pressure from said master cylinder while said pressure regulating means is being controlled in response to the result of the comparison between the desired value and the state variable;
• wherein said one wheel brake cylinder for which the modified desired value is provided by said desired value modifying means, corresponds to the other wheel brake cylinder included in said hydraulic circuit including said wheel brake cylinder operatively associated with said wheel to be controlled, and
• wherein said desired value modifying means modifies the desired value at least in response to operation of said brake pedal, to provide a reference value for the other wheel brake cylinder, and
• wherein said control means controls said pressure regulating means to regulate the hydraulic braking pressure in the other wheel brake cylinder included in said hydraulic circuit including said wheel brake cylinder operatively associated with said wheel to be controlled when said brake pedal is operated to discharge the hydraulic braking pressure from said master cylinder while said pressure regulating means is being controlled in response to the result of the comparison between the desired value and the state variable;
• wherein said vehicle state monitor means includes yaw rate detection means for detecting an actual yaw rate of said vehicle, and
• wherein said control means comprises;
• desired yaw rate setting means for setting a desired yaw rate served as said desired value,
• first yaw rate deviation calculation means for calculating a deviation between the desired yaw rate set by said desired yaw rate setting means and the actual yaw rate detected by said yaw rate detection means,
• desired yaw rate modifying means for modifying the desired yaw rate set by said desired yaw rate setting means at least in response to operation of said brake pedal, to provide a reference yaw rate served as the reference value, and
• second yaw rate deviation calculation means for calculating a deviation between the reference yaw rate provided by said desired yaw rate modifying means and the actual yaw rate detected by said yaw rate detection means,
• and wherein said control means controls said pressure regulating means on the basis of results calculated by said first yaw rate deviation calculation means and said second yaw rate deviation calculation means, to regulate the hydraulic braking pressure in said pair of wheel brake cylinders.