This paper presents a new approach for the design of variable structure control (VSC) of nonlinear systems. The approach is based on estimation of joint acceleration signals with introduction of load estimation with the asymptotic observer. The control system is insensitive to parameter variations for a chosen switching hypersurface in conditions when it is reached by the dynamic motion with the required dynamics. The parameter insensitive response provided by this control method is demonstrated on the model of the SCARA robot. Simulation results confirm the validity of accurate tracking capability and the robust performance.

The dynamics of a mechanical manipulator have the inherent characteristics of being highly non-linear and strongly coupled due to the interaction of the inertial, centripetal, coriolis and gravitational forces.

These characteristics produce difficulties in predicting the dynamic behaviour of a given manipulator's structure. These interactive forces depend largely on the geometrical configuration and operational conditions of a manipulator. Therefore, it is essential to investigate the dynamics behaviour under different conditions in order to obtain an optimal design.

This paper presents a study of the dynamics behaviour of a robot's arm with particular reference to the mechanical manipulator being designed by the AEAC. A computer software package has been developed to facilitate the investigation of the potential dynamics behaviour of a robot's arm and provides the designer with useful information for the real time control of high performance robots. This package also enables the designer to closely monitor the implications of his design.

The software of this package is based on the Lagrangian model, taking advantage of the recursive formulation. A brief description of the types of velocity trajectories used in this study is also included in this paper.

The software for the modelling was written in FORTRAN 77 in single precision and run on a UNIVAC operating system.

This paper deals with the study of the effects of Harmonic Drives characteristics on the dynamic behaviour of industrial robots. These components are firstly analyzed on the basis of the technical literature and, as a result, a mechanical model with concentrated parameters is obtained. Finally, the influence of these parameters on the dynamic behaviour of an actual SCARA robot in our department is investigated by means of experimental tests and by a computer simulation program purposely written.

This paper deals with an investigation of the relative importance of robotic characteristics typically associated with nonlinear manipulators. An IBM 7540 SCARA type of robot is used for simulation, and results are presented for decentralized proportional plus derivative control action applied to individual robot joints, and the use of an adaptive computed torque control strategy is illustrated. The influence of variations in payload and robot parameters on trajectory tracking is also shown.

In this paper, different adaptive control algorithms will be experimentally tested on a two axis SCARA type direct drive robot arm, and the performance of these algorithms will be compared. Being a direct drive system, the nonlinear effects, arising from the dynamics of the manipulator under high velocities, are directly reflected in the control of the manipulator. This makes the manipulator a more efficient test bed for testing the efficiency of the proposed adaptive schemes. In the experiments, we used fast trajectories rather than slow ones to observe how the proposed controllers compensate the dynamic nonlinear effects of manipulator dynamics. We will test some known adaptive control algorithms given in the literature along with our proposed adaptive control scheme which makes use of multiple models.

This paper presents an approach for analyzing the dynamics of initial impact during robotic parts mating represented by peg-in-hole assembly. Lagrange's impact model is used to derive a general form of impact equations for an industrial manipulator performing peg-in-hole assembly. Specific impact equations can then be generated for a given robot to analyze part motions and contact forces in the mating of parts. The impact equations of a SCARA robot are obtained and utilized to investigate how the system parameters affect force impulse and departure angle in the assembly of a peg with a chamfered hole. The resulting information is useful to robot manufacturers in design of robotic equipment and to robot users in determining optimal operational conditions. It is also useful for building an intelligent robot controller capable of deciding on proper values of operation parameters.