Method for converting a rotational speed transducer output signal into a low-distortion signal

A method using a Kalman filter for converting a sinusoidal output signal of a rotational speed transducer, which in its frequency and amplitude is subject to distortion and is dependent on a varying rotational speed that is to be ascertained, into a low-distortion signal which signal is directed to an anti-skid-anti-lock system to prevent wheel slippage, which includes the steps of

• (a) forming at predetermined time intervals, a difference between an output signal (z(k+1)) of the speed transducer and a simulation value (z(k+1)) ascertained in the Kalman filter based on a previous measurement;
• (b) converting this difference (z(k+1)) by multiplication with a Kalman amplification factor K, which represents a vector, into a difference vector x(k+1/k);
• (c) forming a sum x(k+1/k+1) of this difference vector x(k+1/k) and a simulation vector x(k+2)/k+1) and directing the sum x(k+1/k+1) to the anti-skid system to prevent wheel slippage;
• (d) storing this summed vector x(k+2/k+1), which contains the desired low-distortion signal, in a memory, after multiplication by a transition matrix .PHI., as a simualtion vector x(k+2/k+1) for the following sum formation;
• (e) and storing the simulation vector x(k+2/k+1), after multiplication by a measurement vector H, in memory as a simulation value z(k+2) for the following cycle,
• wherein the terms in parentheses (k+m) or (k+m/k+n) indicate that the corresponding variable is used in the evaluation cycle (k+m) and was obtained in the evaluation cycle (k+n).