High-Resolution System Of Unltrasonic Measurment Of Distance

This thesis is aimed at the research into the high-resolution system of ultrasonic measurement of distances. The resolving power has to exceed 0.1mm based on the actual need of the monitoring prediction of the ore pressure.To reach the demand, we reach out the high-resolution system of ultrasonic measurement distance, whose resolution can reach to 0. lmm or higher .This system can raise the laneway convergence monitoring to a new level and have important significant to rock power study theoretical research and engineer practice. It is easy to be installed and applied, low in price and capable of being used in combination with telemetering telecontrol system and has extensive application prospects.From the formula of ultrasonic measurement distance L=V(T2 -T1),so faas measuring the dispath of trasimit time t1 and recept time t2, we can work out the length. But to get high rsolution, the measurment random error must be reduced. Therefore, multiple methods are employed in the system for minimization of random error.To diminish random error, the transmitting circuit should ensure the favorable repeatability the wave shape of the emitted ultrasonic waves. So this system adopt ultrasonic wave measurement distances with only a transmitting circuit and an receiving circuit .The transmitting circuit adopt high-voltage electric discharge driving method, which is simple and original in circuits. The principle for this method is based on the fundamental characteristic of piezoelectric transducers, that is, electrostriction. In the receiving circuit, direct amplification of the signals, band-pass filtering and the turning of comparators are taken as indicators to reception of ultrasonic waves and control the counter door in combination with the pins of the singel chip computer to accurately control the counter and diminish the random error of measurement. In terms...