Abstract In general two basic methods are used for controlling the velocity of a hydraulic cylinder. First by an axial variable-displacement pump for controls flow to the cylinder. This configuration is commonly known as a hydrostatic transmission. Second by proportional valve powered by a constant-pressure source, such as a pressure compensated pump, drives the hydraulic cylinder. In this stud...

We present a hydro-elastic actuator that has a linear spring intentionally placed in series between the hydraulic piston and actuator output. The spring strain is measured to get an accurate estimate of force. This measurement alone is used in PI feedback to control the force in the actuator. The spring allows for high force fidelity, good force control, minimum impedance, and large dynamic ran...

Drive systems are usually modeled using a mathematical characterization of their physical phenomena. However, the difficulty in establishing a relevant model representation, in particular for electro-hydraulic systems, makes important the search for other modeling mechanisms that allow the combination of previously compiled system’s knowledge with acquired experimental information. This paper, ...

This paper will develop a novel electro-hydraulic actuator with energy saving characteristics. system is able to work in differential configurations through the shifting algorithm of valves, meaning that this developed can be adjusted flexibly obtain desirable working requirements including high effectiveness recovery from load, velocity or torque. Instead establishing mathematical model for pu...

Due to time-varying effects in electro-hydraulic actuator (EHA) system parameters, a selftuning control algorithm using pole placement and recursive identification is presented. A discrete-time model is developed using system identification method to represent the EHA system and residual analysis is used for model validation. A recursive least square (RLS) method with covariance resetting techn...

The work presented in this paper is based on a novel integrated and compact hydraulic robotic actuator [1] (BIA patentUS20110085922), intended for the hydraulic humanoid robot HYDROïD. This actuator solves the problem of autonomy for hydraulic humanoid robots as it can be integrated to operate each joint separately. Thus, eliminating the need for a central hydraulic power pack. Also, due to its...

Electro-hydraulic actuator (EHA system) identification is to describe the characteristic of the system that useful for prediction or control system design. There are numerous methods of EHA modeling but there has not been much model using fractional-order (FO) model. In this work, integer-order (IO) model and FO model are developed to model EHA system. Output-error method is used as the estimat...