Hydraulic machines used in mining and excavation applications are non-linear systems. Besides the nonlinearity due to the dynamic coupling between the different links there are significant actuator non-linearities due to the inherent properties of the hydraulic system. Optimal motion planning for these machines, i.e. planning motions that optimize a user-selectable combination of criteria such ...

In this paper, different approaches to solve the forward kinematics of a three DOF actuator redundant hydraulic parallel manipulator are presented. On the contrary to series manipulators, the forward kinematic map of parallel manipulators involves highly coupled nonlinear equations, which are almost impossible to solve analytically. The proposed methods are using neural networks identification ...

Active hydraulic mounts with an inertia track, decoupler membrane, and oscillating coil actuator (AHM-IT-DM-OCAs) have been studied extensively due their compact structure large damping in the low-frequency band. This paper focuses on a comprehensive analysis of active passive dynamics fixed points mid-low-frequency bands, which will be helpful for parameter identification. A unified lumped mec...

This paper presents a novel nonlinear estimator called the fuzzy finite memory (FFM) state for electro-hydraulic active suspension systems, based on techniques and impulse response. The Takagi-Sugeno model is introduced to effectively describe highly systems with actuator dynamics. Compared conventional estimator, which has an infinite structure requires whole data from initial current time, pr...

Hydraulic machines used in mining and excavation applications are non-linear systems. Besides the nonlinearity due to the dynamic coupling between the different links there are significant actuator non-linearities due to the inherent properties of the hydraulic system. Optimal motion planning for these machines, i.e. planning motions that optimize a user-selectable combination of criteria such ...

In this paper the control problem of a hydraulic servo-system is addressed. The performance achievable by classical linear controllers, e.g. PD, are usually limited due to highly nonlinear behavior of the hydraulic dynamics. This paper adopts the backstepping design strategy to develop a Lyapunov-based nonlinear controller for a hydraulic servo-system. Load, hydraulic and valve dynamics are inc...

A study of published literature and information from piezoelectric, electrostrictive, and magnetostrictive actuator vendors has been undertaken to establish the mechanical and electrical operating characteristics of the actuators, and to compare them using output energy density criteria. Output energy values of up to 0.666 J can be achieved with off-the-shelf actuators. Energy density per unit ...

ABSTRACT: To develop an unmanned automatic excavator system the control performance of hydraulic actuators should be guaranteed. However, hydraulic actuators with single rod cylinder have inherently severe nonlinearities that significantly affect to the command following performance of end-effect. PID control system widely used in industries is not proper to compensate the nonlinearities and it...

This note examines the robustness properties of the nonlinear PI control method to ignored actuator dynamics. It is proven that global boundedness and regulation can be achieved for sector bounded nonlinear systems with unknown control directions if the actuator dynamics are sufficiently fast and the nonlinear PI control gain is chosen from a subclass of the Nussbaum function class. Simulation ...

Advancements in Sugar include 1) parameterizable netlists, 2) nonlinear frequency response analysis, 3) subnets, 4) improved MNA, 5) reduced order modeling, and 6) a more accurate nonlinear beam model. Examples of these features include the simulation of a two-axis mirror with over 10,000 degrees of freedom, the reduced order modeling applied of an electrostatic gap actuator, the parameterized ...