Vehicle rollover sensing using extended kalman filter

An apparatus for estimating a current attitude angle of a vehicle comprising:

• an angular roll rate sensor for measuring roll rate of a vehicle and producing an output signal indicative thereof;
• an angular pitch rate sensor for measuring pitch rate of the vehicle and producing an output signal indicative thereof;
• a longitudinal accelerometer for measuring longitudinal acceleration of the vehicle and producing an output signal indicative thereof;
• a lateral accelerometer for measuring lateral acceleration of the vehicle and producing an output signal indicative thereof;
• a vertical accelerometer for measuring vertical acceleration of the vehicle and producing an output signal indicative thereof;
• and
• a non-linear filter for receiving signals from said angular roll rate and pitch rate sensors and said longitudinal, lateral, and vertical accelerometers, and said non-linear filter estimating a roll angle and a pitch angle based on said received signals.

A method for predicting an overturn condition of a vehicle, said method comprising the steps of:

• sensing angular roll rate of a vehicle and producing an output signal indicative thereof;
• sensing angular pitch rate of the vehicle and producing an output signal indicative thereof;
• sensing longitudinal acceleration of the vehicle and producing an output signal indicative thereof;
• sensing lateral acceleration of the vehicle and producing an output signal indication thereof;
• sensing vertical acceleration of the vehicle and producing an output signal indicative thereof;
• estimating a roll angle and a pitch angle with a non-linear filter as a function of said sensed angular roll and pitch rates and said sensed longitudinal, lateral, and vertical accelerations;
• predicting a roll angle based on said estimated roll angle and said sensed roll rate;
• predicting a pitch angle based on said estimated pitch angle and said sensed pitch rate;
• comparing said predicted roll angle to a roll threshold value;
• comparing said predicted pitch angle to a pitch threshold value;
• and
• deploying a vehicle overturn condition signal based on either of said comparisons.

A method of estimating a current attitude angle of a vehicle, said method comprising the steps of:

• sensing angular roll rate of a vehicle and producing an output signal indicative thereof;
• sensing angular pitch rate of the vehicle and producing an output signal indicative thereof;
• sensing longitudinal acceleration of the vehicle and producing an output signal indicative thereof;
• sensing lateral acceleration of the vehicle and producing an output signal indicative thereof;
• sensing vertical acceleration of the vehicle and producing an output signal indicative thereof;
• and
• estimating a roll angle and a pitch angle with a non-linear filter as a function of said sensed angular roll and pitch rates and said sensed longitudinal, lateral, and vertical accelerations.