Monitoring piston displacement of hydraulic accumulator based on radar wave technology

Piston accumulator is a special pressure vessel with a design pressure up to 31.5MPa, which can be used as an energy storage device in the hydraulic/pneumatic system, and plays an important role in energy saving and emission reduction for large construction machinery. The condition of the accumulator not only reflects the operating status of the hydraulic system, but also helps to diagnose the faults of the hydraulic-pneumatic system, so it is significant to monitor the displacement of the piston in the accumulator in real time. Aiming at the harsh conditions of high temperature, high pressure, volatile materials, and low visibility in the accumulator, a non-contact, miniaturized, and high-precision linear FMCM radar technology for piston displacement detection has been developed. Compared with the actual displacement, the relative errors of measurements by radar technology are 0.0053m and 0.0073m, respectively. It means that the radar ranging method has a great potential in terms of ranging accuracy, computational efficiency, and applicability of condition monitoring in the hydraulic accumulator.