Theoretical and experimental studies of a switched inertance hydraulic system

Abstract

A switched inertance hydraulic system uses a fast switching valve to control flow or pressure and is potentially very efficient as it does not rely on dissipation of power by throttling. This article studies its performance using an analytical method which efficiently describes the system in the time domain and frequency domain. A lumped parameter model and a distributed parameter model have been used for investigation using different parameters and conditions. The analytical models have been validated in experiments and the results on a prototype device show a very promising performance. The proposed analytical models are effective for understanding, analysing and optimizing the characteristics and performance of a switched inertance hydraulic system.

Theoretical and Experimental Studies of a Switched Inertance Hydraulic System in a Four-Port High-Speed Switching Valve Configuration  

“…The analytical and experimental results match well and indicate that the delivery pressure has a linear relationship with the switching ratio. Unlike the results from an SIHS in a three-port valve configuration [4], the four-port valve configuration is shown to be able to generate bidirectional pressure difference across the load. …”

“…This is in contrast to the lumped parameter model [4,8]. Analytical distributed parameter models of an SIHS in threeport valve configuration have been created and validated in simulation in the authors' recent work [7].…”

A Global Optimisation of a Switched Inertance Hydraulic System based on Genetic Algorithm

“…An enhanced analytical model of an SIHS including switching transition dynamics, non-linearity and leakage in a three-port switching valve configuration is created and validated in author's previous work [4,5]. The model is applied for this study.…”

“…where pH and pL are high and low supply pressures, qloss is the flow loss of the system [4,5], qm is the average delivery flow rate and Rt is the overall system resistance.…”

“…To achieve bi-direction control ability, the four-port SIHS is introduced, as shown in Figure 2, where two inertance tubes and accumulators were used in the system, providing real four-quadrant operation and seamless changes in direction, such as four-port modulating valves. The threeport and four-port SIHS have been investigated analytically and experimentally at the Centre for Power Transmission and Motion Control at the University of Bath [4][5][6][7][8].…”