In a method for ascertaining whether a target object can be driven over by the controlled motor vehicle, with the aid of frequency-modulated radar signals of a radar sensor, amplitude ratios between received radar signals reflected from the target object are utilized, the received radar signals corresponding to signals which have been transmitted in different frequency ranges. In some examples, the system receives information that indicates possible tampering of utility meter by a customer of a utility. The light-shielding wall includes a plurality of inclined surfaces that are inclined with respect to an imaging plane of the imaging regions, and the plurality of inclined surfaces are disposed sequentially from a side of the lens module to a side of the imaging regions. Clogging of the slurry sampling tube is thus eliminated, thereby ensuring robust operation of the CMP apparatus. Moreover, queries are reduced to a canonical form. By removing old data which the classifier would classify differently were the old data re-labelled as new, a selective purging of the old training data takes place each time new training data becomes available.