Modelling and simulation of sensors for position control for hydraulic mechatronic systems

Many electro-hydraulic applications like automated manufacturing tools and systems, robotics or seismic test benches for civil engineering require precise control of hydraulic cylinders. This control can be obtained only using reliable and accurate position sensors, usually resistive or inductive. The paper presents design, modelling, simulation and implementation of two types of position sensors for hydraulic mechatronic systems - differential inductive type and integrated accelerometer-based. Both sensors use microcontrollers for data processing and communication. Each type has its advantages - the inductive sensor is more accurate, accelerometer-based one requires simpler mechanical construction. The idea of using of accelerometer-based sensor was to replace standard displacement transducer attached on the cylinder with an accelerometer connected to a microcontroller that reads acceleration data and calculates displacement, thus eliminating mechanical coupling between cylinder rod and cylinder body. Both solutions are analyzed and compared on the same hydraulic test bench.