Attitude sensing system for an automotive vehicle relative to the road

A control system for an automotive vehicle having a vehicle body comprising:

• a roll angular rate sensor generating a roll angular rate signal corresponding to a roll angular motion of the vehicle body;
• a yaw angular rate sensor generating a yaw motion signal corresponding to a yaw motion of the vehicle body;
• a lateral accelerometer generating a lateral acceleration signal corresponding to a lateral acceleration of a center of gravity of the vehicle body;
• a longitudinal accelerometer generating a longitudinal acceleration signal corresponding to the longitudinal acceleration of the center of gravity of the vehicle body;
• a wheel speed sensor generating a wheel speed signal corresponding to a wheel speed of the vehicle;
• and
• a controller coupled to said roll angular rate sensor, said yaw angular rate sensor, said lateral accelerometer, said longitudinal accelerometer, and said wheel speed sensor, said controller determining a pitch rate in response to said roll angular rate signal, said yaw motion signal, said lateral acceleration signal, said longitudinal acceleraton signal, and said wheel speed signal, said controller determining a roll gradient based upon a past raw roll rate and current raw roll rate, the roll angular rate signal and the lateral acceleration signal:
• a pitch gradient based upon a past raw pitch rate and current raw pitch rate, the calculated pitch angular rate signal and the longitudinal acceleration signal, determining a relative roll and relative pitch as a function of the roll gradient and the pitch gradient.

A method of controlling a rollover system for a vehicle body of an automotive vehicle comprising:

• measuring a roll rate of the vehicle body;
• measuring a lateral acceleration of the vehicle body;
• measuring a longitudinal acceleration of the vehicle body;
• measuring a yaw rate of the vehicle body;
• determining a calculated pitch rate signal from the yaw rate, the roll rate, the lateral acceleration and the longitudinal acceleration;
• determining a global roll attitude and a global pitch attitude from the calculated pitch angular rate, the roll rate, lateral acceleration and the longitudinal acceleration;
• determining a roll gradient based upon a past raw roll rate, the roll rate signal and the lateral acceleration signal;
• determining a relative roll angle based upon said roll gradient;
• determining a pitch gradient based upon a past raw pitch rate and calculated pitch rate and the longitudinal acceleration signal;
• determining a relative pitch angle based upon said pitch gradient;
• and
• activating a safety device in response to the relative roll angle, the relative pitch angle, the global roll and global pitch angle.

A method of controlling a safety system for a vehicle body of an automotive vehicle comprising:

• measuring a roll rate of the vehicle body;
• measuring a lateral acceleration of the vehicle body;
• measuring a longitudinal acceleration of the vehicle body;
• measuring a yaw rate of the vehicle body;
• and
• determining a relative roll angle, a relative pitch angle, a global roll and a global pitch angle in response to the roll rate, the yaw rate, the lateral acceleration and the longitudinal acceleration.