Abstract: A method for determining a risk of instability of a calculation of an angle ? of a steering shaft of a motor vehicle can be employed where a first gear wheel is fixed to the steering shaft and cooperates with a second gear wheel and a third gear wheel, which are smaller than the first gear wheel. The number of teeth of the first gear wheel is n. The number of teeth of the second gear wheel is m. And the number of teeth of the third gear wheel is m+1. The angles ? and ? of the two smaller gear wheels are determined and the angular position ? of the steering shaft is calculated by evaluating the equation ? = m * ? + ( m + 1 ) * ? - ( 2 ? m + 1 ) * k * ? 2 ? n , with ? being an angle of the sensor range and a whole number k given by k = round ? ( ( m + 1 ) * ? - m * ? ? ) , wherein the risk of instability is determined by calculation of a stability margin t according to t = k - ( ( m + 1 ) * ? - m * ? ? ) .

Abstract: A method for determining a risk of instability of a calculation of an angle ? of a steering shaft of a motor vehicle can be employed where a first gear wheel is fixed to the steering shaft and cooperates with a second gear wheel and a third gear wheel, which are smaller than the first gear wheel. The number of teeth of the first gear wheel is n. The number of teeth of the second gear wheel is m. And the number of teeth of the third gear wheel is m+1. The angles ? and ? of the two smaller gear wheels are determined and the angular position ? of the steering shaft is calculated by evaluating the equation ? = m * ? + ( m + 1 ) * ? - ( 2 ? m + 1 ) * k * ? 2 ? n , with ? being an angle of the sensor range and a whole number k given by k = round ? ( ( m + 1 ) * ? - m * ? ? ) , wherein the risk of instability is determined by calculation of a stability margin t according to t = k - ( ( m + 1 ) * ? - m * ? ? ) .

Abstract: A method may be used to error compensate a measurement of an electric motor's rotor position in a power steering system of a motor vehicle. The electric motor generates torque for assisting steering of the motor vehicle, and stray magnetic fields of motor currents affect the measurement of the rotor position with a magneto-resistive rotor position sensor. The method may involve calculating at least two compensation values based on a current vector, rotor position, and hardware dependent parameters. The at least two compensation values account for errors in the rotor position measurement due to stray magnetic fields of motor currents. The method may also involve calculating a compensated rotor position signal by subtracting the at least two compensation values of the measured rotor position, as well as transferring the compensated rotor position signal as part of a feed-back loop to a target motor torque determination in the motor control.

Abstract: A method may be used to error compensate a measurement of an electric motor's rotor position in a power steering system of a motor vehicle. The electric motor generates torque for assisting steering of the motor vehicle, and stray magnetic fields of motor currents affect the measurement of the rotor position with a magneto-resistive rotor position sensor. The method may involve calculating at least two compensation values based on a current vector, rotor position, and hardware dependent parameters. The at least two compensation values account for errors in the rotor position measurement due to stray magnetic fields of motor currents. The method may also involve calculating a compensated rotor position signal by subtracting the at least two compensation values of the measured rotor position, as well as transferring the compensated rotor position signal as part of a feed-back loop to a target motor torque determination in the motor control.