Large Range Of Ultrasonic Ranging Study

Ultrasonic distance measurement with large action-range in air is widely used in many robotic and automatic applications, for example, fieldwork robots, self-guided autonomous vehicles, obstacle avoidance and collision warning systems of vehicle, and so on. This paper probes into the multi-branch of knowledge, such as the mechanical structure of the transducer, the driving electronics, the echo receiving circuits, and the signal processing, which is applied to extend the action-range of ultrasonic distance measurement system. In light of this, a new ultrasonic distance measurement device with large action-range is developed.Firstly, the piezoelectric effects and piezoelectric ultrasonic transducer are studied. An ultrasonic transducer of large action-range is presented.Secondly, through theory calculation, a noval driving circuit of ultransonic transducer and an echo receiving circuit according AGC with single-power are designed, which extend the dynamic range of echo signal. Based on DAQ of NI, the hardware platform of ultrasonic distance measurement system is set up.Finally, to improve the performances of ultrasonic distance measurement system in hand, adaptive time-delay estimation signal processing techniques are investigated carefully. The relative merits of this algorithm are discussed in detail. Computer simulation of this algorithm is done and performance analysis is made. By means of software simulation based on variable step size adaptive filtering algorithm, we have obtained from a set of experimental data some instructive conclusions of the superior and inferior of the algorithms, which are of great significance for implementation of a practical ultrasonic distance measurement system.