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

Abstract

Abstract:The switched inertance hydraulic system (SIHS) is a novel high-bandwidth and energy-efficient digital device which can adjust or control flow and pressure by a means that does not rely on throttling the flow and dissipation of power. An SIHS can provide an efficient step-up or step-down of pressure or flow rate by using a digital control signal. In this article, analytical models of an SIHS in a four-port high-speed switching valve configuration are proposed, and the system dynamics and performance are investigated theoretically and experimentally. The flow responses, system characteristics, and power consumption can be predicted effectively and accurately by using the proposed models, which were validated by comparing with experiments and with numerical simulation. The four-port configuration is compared with the three-port configuration, and it is concluded that the former one is less efficient for valves of the same size, but provides a bi-direction control capability. As bi-direction control is a common requirement, this constitutes an important contribution to the development of efficient digital hydraulics.

Switching characteristics of a high-speed rotary valve for switched inertance hydraulic converters

“…A typical SIHC consists of high-speed switching valves, inertance tubes and accumulators. 1 It can be configured in a variety of ways, such as a flow booster, 2 pressure booster, 3 bi-directional four-port converter and switching gyrator 4 for a wide range of hydraulic applications. Figure 1 shows the configuration of a flow booster that can deliver more flow than the supply flow.…”

“…The valve has been used in the experimental validation for SIHC investigations. 4,18 However, the switching characteristics such as the switching orifice area and the dynamics of the valve were not systematically studied.…”

The Hydraulically Controlled Oscillating Piston Converter

“…Ref. [4] gives an overview of this work; [5][6][7][8][9][10][11] are important contributions of recent years. In these cases, the inertia is realized by the fluid in a so-called inertance pipe.…”

Analysis of the Energy Efficiency Improvement in a Load-Sensing Hydraulic System Built on the ISO Plate

“…As a result, a hydraulic stepper converter consisting of a hydraulic cylinder piston unit and a fast-switching valve was developed [4] and oscillating mass converter (OMC) with a pure hydraulic control [5] was proposed. Similarly, fast-switching valves were used by Pan et al [6] in a novel approach for increasing energy efficiency in the fluid power systems, that resulted in an approximately one-seventh reduction in power loss compared to a conventional system based on throttle valves. Another proposal of an energy saving strategy for an electrohydraulic servo valve system was proposed by W. Wang and B. Wang [7].…”