Method and apparatus for reliably detecting a kinematic size of a manipulator

An inventive method for the safe detection of a kinematic size of a manipulator comprising the steps of: (S10) detecting a kinematic size (.alpha..sub.i) of the manipulator at different time points (t0, t1, t2, t3) by a detecting device; (S20): determining a temporal change (dαi / dt, d (S30, S35): Check whether the change over time in a predetermined plausible range (aizul, rizul) is located; (S30, S35): determining a plausibility of the detected kinematic variable on the basis of this check, and (S40) outputting a secure kinematic size (asf, vsf) based on the detected kinematic variables, if the time change is in the plausible range.