We can see from practical measureme

We can see from practical measurements [5] that the ultrasonic sensor measures the distance with high accuracy. In measurements distances up to 3m was accuracy class 0.5 , in case measurements distances up to 6m was accuracy class 0.7 and in case measurements distances over 6 meters the accuracy class was even 0.4. The accuracy of the sensor was in all cases related to the measurement range (including the accuracy of the tape-meter). Manufacturer of the sensor indicates the maximum measurement error 3-4 cm in his data sheets. This accuracy was confirmed with reserve. When verifying the directional characteristics the object was detected approximately at the same angle, as determined by the manufacturer. All measurements were realized approximately under the same conditions (temperature T = 23C).