Given the influence of flow instability, parameter uncertainty, and unpredictable disturbances in electro-hydraulic lifting systems, high-precision position control for systems is challenging to achieve. This study proposes an observer–sliding mode strategy improve accuracy tractor system. Firstly, principle hoisting system analyzed. Secondly, a mathematical model established, reduced design ob...

In order to coordinate the damping performance and energy regenerative performance of energy regenerative suspension, this paper proposes a structure of vehicle semi-active energy regenerative suspension with electro-hydraulic actuator (EHA). In light of the proposed concept, a specific energy regenerative scheme is designed and the mechanical properties test is carried out. Based on the test r...

This paper describes the development of a new piezohydraulic actuator for broadband microjet flow control applications. The actuator utilizes a lead zirconate titanate (PZT) stack actuator and a hydraulic amplification design to achieve relatively large displacements in a compact actuator to control flow through a microjet orifice. Displacement amplification of 81 times the stack actuator displ...

The internal leakage fault-tolerant control problem of the electro-hydraulic servo actuator under influence multiple unmodeled dynamics is investigated in this paper, and an adaptive scheme based on estimation compensation proposed. model divided into two subsystems, which extended-state observers are respectively constructed to estimate matched mismatched dynamics. Combined with results dynami...

Hydraulic machines used in a number of applications are highly non-linear systems. Besides the dynamic coupling between the different links, there are significant actuator non-linearities due to the inherent properties of the hydraulic system. Automation of such machines requires the robotic machine to be atleast as productive as a manually operated machine, which in turn make the case for perf...

The time delay of variable valve actuators has a significant influence on engine lift tracking performance. For camless hydraulic actuators, response is affected by many factors, such as friction and control response. In this paper, investigated in depth. Experiment results show that motion can be divided into open close delay. They are different even the same cycle. Complicated characteristics...

Hydrodynamic and aerodynamic lubrication regimes in their controllable forms have been intensively investigated over the last two decades. With the aim of reducing friction and improving thermal, static, and dynamic characteristics of radial sliding bearings, different types of electro-mechanical actuators have been coupled to such bearings. Depending on (i) the actuator type; (ii) the actuatio...

This paper reports on the design of a biorobotic actuator. Biological requirements are developed from published reports in the muscle physiology literature whose parameters are extracted and applied in the form of the Hill muscle model. Data from several vertebrate species (rat, frog, cat, and human) are used to evaluate the performance of a McKibben pneumatic actuator. The experimental results...