Patent ID: 8781706

Claim:
An apparatus for monitoring one or more target objects in an environment external to a vehicle by means of at least one sensor, the apparatus being arranged to trigger at least one action responsive to the detection of prescribed relative movement between the vehicle and the one or more target objects, wherein the apparatus is arranged to store a value of a reference angle parameter indicative of a reference angle of misalignment of the at least one sensor; to determine whether the at least one sensor is correctly aligned with respect to the vehicle by comparing a measured value of misalignment angle with the reference angle; not to trigger the at least one action unit the apparatus has determined that the at least one sensor is correctly aligned when the apparatus commences monitoring of the environment and, thereafter, to allow triggering of the at least one action when the apparatus has determined that the at least one sensor is correctly aligned; and not to permit triggering of the at least one action when it is determined that a difference between a single measured angle of misalignment and the reference angle is greater than a prescribed tolerance angle.