Vehicle rollover detection and mitigation using rollover index

A system for controlling a vehicle to prevent rollover, comprising:

• a plurality of vehicle suspension displacement sensors;
• a vehicle lateral acceleration sensor;
• a vehicle roll rate sensor;
• a vehicle brake subsystem;
• a vehicle steering subsystem;
• and
• a processor coupled to the vehicle suspension displacement sensors, the vehicle lateral acceleration sensor, the vehicle roll rate sensor, the vehicle brake subsystem and the vehicle steering subsystem, the processor executing code for instructing the processor to perform the steps of:
• measuring lateral acceleration of the vehicle as provided by the lateral acceleration sensor;
• measuring one of a vehicle roll rate as provided by the roll rate sensor and vehicle suspension displacements as provided by the vehicle suspension displacement sensors;
• deriving an estimated roll angle from the measured lateral acceleration and the measured one of the vehicle roll rate and the vehicle suspension displacements;
• deriving a roll control term from at least the measured lateral acceleration, the measured one of the vehicle roll rate and the vehicle suspension displacements and the estimated roll angle, wherein a magnitude of the roll control term provides an indication of a rollover danger and a sign of the roll control term provides a direction of impending rollover;
• and
• controlling at least one of vehicle brake subsystem and vehicle steering subsystem to reduce the possibility of rollover responsive to the roll control term.

A method for controlling a vehicle to prevent rollover, comprising the steps of:

• measuring lateral acceleration of a vehicle;
• measuring one of a vehicle roll rate and vehicle suspension displacements;
• deriving an estimated roll angle from the measured lateral acceleration and the measured one of the vehicle roll rate and the vehicle suspension displacements;
• deriving a roll angle index from a comparison of at least the measured lateral acceleration, the measured one of the vehicle roll rate and the vehicle suspension displacements and the estimated roll angle, wherein a magnitude of the roll angle index provides an indication of a rollover danger and a sign of the roll angle index provides a direction of impending rollover;
• and
• controlling at least one of vehicle braking and vehicle steering to reduce the possibility of rollover responsive to the roll angle index when the magnitude of the roll angle index is greater than a predetermined value.