SENSOR MODULE FOR HYDRAULIC BOOM STATE FEEDBACK CONTROL

Abstract

Hydraulic systems are known to be characterized by poor damping that causes motion oscillations and this limits the obtained hydraulic actuator velocity. Well-known techniques for increasing hydraulic system damping include oversizing hydraulic actuators, introduction of additional leakages and high-pass filtered pressure or acceleration feedback. The acceleration feedback is a very effective solution but usually the introduction of acceleration sensors increases the overall system cost or the sensors lack adequate robustness against required harsh environmental conditions. In this paper, an implementation of acceleration feedback based on Micro-Electro-Mechanical Systems (MEMS) technology is presented. The proposed solution incorporates a MEMS accelerometer and gyroscope into a sensor module for closedloop position control and active damping of a hydraulic boom. The performance of the sensor module prototype is experimentally demonstrated on a hydraulic test bench. The results show increased system damping that enables a 47% faster response in the closed-loop position control experiments presented. The achieved steady-state positioning repeatability was within ± 0.06 deg. These results show the feasibility of the proposed solution in such industrial applications, where the productivity of the work is hampered by motion oscillation of the hydraulic actuators.