System for detecting surface profile of a driving 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 an roll angular motion of the vehicle body;
• a yaw angular rate sensor generating a yaw rate signal corresponding to a yaw motion of the vehicle body;
• a lateral acceleration sensor generating a lateral acceleration signal corresponding to a lateral acceleration of a center of gravity of the vehicle body;
• a longitudinal acceleration sensor 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 acceleration sensor, said longitudinal acceleration sensor, and said wheel speed sensor, said controller determining a relative pitch angle and relative roll angle as a function of the lateral acceleration signal, the longitudinal acceleration signal and the roll rate signal, determining a first flatness index as a function of the roll angular rate signal, the yaw angular rate signal, the relative roll angle and a relative pitch angle, said controller determining a steady state pitch angle as a function of the vehicle speed and the longitudinal acceleration, said controller determining a steady state roll angle as a function of lateral acceleration, vehicle speed and yaw rate, said controller determining a second flatness index as a function of the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle.

A method controlling an automotive vehicle comprising:

• estimating a first flatness index indicative of road flatness;
• estimating a second flatness index indicative of road flatness;
• determining a road pitch slope in response to the first flatness index and the second flatness index;
• and
• determining a road bank angle in response to the first flatness index and the second flatness index.

A method of controlling an automotive vehicle comprising:

• measuring a roll rate of the vehicle body;
• measuring a lateral acceleration of the vehicle body;
• measuring the longitudinal acceleration of the vehicle body;
• measuring the yaw rate of the vehicle body;
• measuring a vehicle speed;
• determining a relative pitch angle and relative roll angle as a function of the lateral acceleration, the longitudinal acceleration and the roll rate signal;
• determining a first flatness index as a function of the roll angular rate, the yaw angular rate, the relative roll angle and a relative pitch angle;
• determining a steady state pitch angle as a function of the vehicle speed and the longitudinal acceleration;
• determining a steady state roll angle as a function of lateral acceleration, longitudinal speed and yaw rate;
• a determining a second flatness index as a function of the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle;
• and
• generating a control signal as a function of the first flatness index and the second flatness index.