Actuator fault diagnosis problem is studied for a class of nonlinear systems with relative degrees from the inputs to the outputs higher than one. This type of nonlinear systems include many mechanical systems, and their actuator fault diagnosis problem can be very challenging because of nonlinearities and high relative degrees. In this paper, in order to solve the actuator fault diagnosis prob...

Computing optimal motions for any robot requires a good model, and a method to compute the optimal motions using that model. As research is conducted into automating operations in construction, excavation etc. there arises a need to compute optimal motions for the hydraulic machines used in these areas. Hydraulic machines disallow a simple extension of work done previously on optimal motion pla...

This paper studies the precision motion control of single-rod hydraulic actuators with time-varying unknown inertia loads. The swing motion control of a robot arm driven by a single-rod hydraulic actuator (a scaled down version of industrial backhoe loader arm) is used as a case study. During the swing motion, the eeective mass acting on the hydraulic actuator varies greatly with the swing angl...

Seven different Radial Basis Functions have been applied in a Feedforward Neural Network and tested on five different real or simulated multivariate modelling problems. A short theory of Radial Basis Functions is presented as well as the particular implementation of the Radial Basis Function Network (RBFN). The real world data modelling problems are; identifying the dynamic actuator characteris...

In this paper, different approaches are presented to solve the forward kinematics of a three DOF actuator redundant hydraulic parallel manipulator. It is known, that 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 mainly numeri...

In this paper, a quasi-closed solution method is presented to solve the forward kinematics of a three DOF actuator redundant hydraulic parallel manipulator. It is shown, that on the contrary to series manipulators, the forward kinematic map of the parallel manipulators involves highly coupled nonlinear equations, which are almost impossible to solve analytically. The proposed method uses a comb...

Analysis and estimation of friction and compensation for its effects in the control of an electrohydraulic manipulator is addressed in this paper. The specific hydraulic manipulator is an integral part of an automated fish processing machine which has been developed in our laboratory. The analysis reveals that considerable static and dynamic friction exists in the system. An available nonlinear...

A new method for function approximation and system identification based on the SelfOrganizing Map is presented. The standard Self-Organizing Map (SOM) is extended with Local Linear Mappings to enable the original algorithm to learn input-output relationships with reasonable accuracy. To every node in the SOM along with the input weight two output weights are assigned: one that stores the output...