Patent ID: 7176789

Claim:
A method for distance measurement using at least two contact-less distance sensors each having one emitter for emitting measuring pulses and one receptor for receiving measuring pulse echos, a distance between a distance sensor and an obstacle that reflects a measuring pulse being determined from a time difference between an emitted measuring pulse and a corresponding received measuring pulse echo, the method comprising: alternatingly emitting a first measuring pulse by a first distance sensor and a second measuring pulse by a second distance sensor for a first measurement, the first and second measuring pulses being offset in time by a first offset; alternatingly emitting a third measuring pulse by the first distance sensor and a fourth measuring pulse by the second distance sensor for a verification measurement, the third and fourth measuring pulses being offset in time by a second offset different from the first offset; receiving, by the first and second distance sensors, measuring pulse echos reflected by an obstacle; establishing, for each measuring pulse echo, a tolerance receiving time range for receiving the reflected measuring pulse echo; and correlating a measuring pulse echo received in response to the first measurement, and a measuring pulse echo received in response to the verification measurement, to detect if a directly reflected measuring pulse echo is received in response to the verification measurement within the tolerance receiving time range.