the depth control systems used in iranian tractors are mechanical and they produce variable tillage depth in uneven field surface. in this research a rotary type electronic control valve was designed and constructed. by using this valve, electro-hydraulic tillage depth control system was developed and installed on the tractor. the control system was composed of: a depth sensor, a programmable l...

This paper reports on the design of a biorobotic actuator intended for use in a powered, below-knee prosthesis. Design requirements for the artificial muscle and tendon are based on the properties of the natural limb. As biological properties often exhibit significant variability, data from a variety of vertebrate species are extracted from published reports in the biological literature and use...

We investigated small-scale hydraulic power actuation systems using a system level analysis, where smallscale refers to systems generating 10 to 100 Watts output power, to determine whether the high power density advantage of hydraulics holds at small sizes. Hydraulic actuator system power density was analyzed with simple physics models and compared to an equivalent electromechanical system com...

Abstract: Addressing the simulating issue of the helicopter-manipulating booster aerodynamic load with high-frequency dynamic load superimposed on a large static load, this paper studies the design of the robust controller for the electro-hydraulic loading system to realize the simulation of this kind of load. Firstly, the equivalent linear model of the electro-hydraulic loading system under as...

This paper studies the motion control of single-rod hydraulic actuators regulated by proportional directional control(PDC) valves with deadband and nonlinear flow gains. The boom motion control of a hydraulic robot arm driven by a singlerod hydraulic actuator is used as a case study. The experimental system dynamics are highly nonlinear. In addition, the system has large extent of modeling unce...

A position-based impedance controller is proposed and demonstrated on an existing hydraulic press with a two-way vertically mounted hydraulic cylinder driven by a servo-solenoid valve. A proportional-integral-derivative (PID) controller and a Fuzzy Logic Controller (FLC) are primarily developed to meet the accurate positioning requirements of the impedance control formulation. The impedance fil...

Robustness and fault-tolerance are desirable properties for hydraulic working machines and field robots. In applications where service personnel do not have easy access to the machine, it is important that the machine can continue its operation despite single machinery faults. Digital hydraulics enables a design which is inherently fault-tolerant by having each hydraulic actuator controlled by ...