Patent ID: 7580784

Claim:
A method for determining a longitudinal inclination variable representing a longitudinal inclination of a roadway, using a sensor arrangement situated in a motor vehicle, the method comprising: determining the variable representing the longitudinal inclination of the roadway as a function of a first unbraked driving state of the vehicle; determining the variable representing longitudinal inclination of a second driving state of the vehicle in which at least one brake is actuated; in the first driving state, determining a first difference between a vehicle longitudinal acceleration determined by a model and a vehicle longitudinal acceleration determined by evaluating wheel speed sensor signals; in the second driving state, determining a second difference between a vehicle longitudinal acceleration determined by a model and a vehicle longitudinal acceleration determined by evaluating wheel speed sensor signals; in the second driving state, determining a second difference between a vehicle longitudinal acceleration determined by a model and a vehicle longitudinal acceleration determined by evaluating wheel speed sensor signals; determining a correction term as a function of the first and second differences; determining a rough inclination variable representing a rough value of the longitudinal inclination of the roadway; determining a value of the longitudinal inclination variable by adding a correction term to the rough inclination variable; and determining the correction terms as a function of the first and second driving states.