Measuring and monitoring circuit for hydraulic cylinders follows movement of pistons by using ultrasonic sensors and piezoelectric elements connected to evaluation circuit

摘要

The measuring and monitoring system has two rows (A,B) of piezoelectric elements attached to the walls of the hydraulic cylinders. The ultrasonic sensors (10) and piezoelectric elements can follow the movement of the pistons in the cylinders and are connected to analog switches (13,14). The switches are connected to triggers (15,16) and Sample and Hold stages (17,18). The Sample and Hold stages are connected to a differential amplifier (19). The triggers are connected to a microprocessor (muP) giving coarse (Ps1) and fine (Ps2) position signals.