The problem of dynamic control of manufacturing systems is addressed, and a solution is proposed in terms of a state reconstruction algorithm, that allows to exactly compute system performance under perturbed values of some system parameters. The control scheme is able to react to disturbances acting on the system. It is applied to a multi part-type manufacturing system, with the purpose of dynamically allocating buffer capacities in order to maximize system throughput. Simulation results are presented to illustrate the effectiveness of the scheme.

The paper discusses the modelling issues for a two link flexible robot arm. The exact dynamic model of the robot arm is derived, and approximate forms suitable for the analysis and control design are proposed. The approach used here to derive an approximate finite dimensional model of the flexible robot arm is based on the Ritz expansion method. Simulations and experimental tests have been carried out to validate the approximate dynamic model of the robot.

An approach to the design of control laws for robot manipulators is proposed. This approach can be applied to robots having flexible joints as well. An application to the case of unknown parameters is also given with reference to a single-link robot with one revolute elastic joint. A drawback to the method considered is the complexity of the resulting control law, as shown by the single-link example. Some simulation results for a three-link rigid robot are also presented.>

A simple asymptotic observer is proposed for the estimation of the generalized velocities of a robotic manipulator. Singular perturbation theory is used in the stability analysis of the error dynamics. High gains are used in the cancellation of the nonlinearities characterizing the dynamic behavior of the robot. The accuracy of the proposed algorithm is illustrated in simulation runs and verified through some experimental tests.>

Robot manipulators in which the joints exhibit a certain amount of elasticity are discussed. The model of such robots is highly nonlinear, and available techniques to build nonlinear observers generally do not apply. A procedure to construct approximate nonlinear observers is proposed that uses a recent approach to deriving observers based on geometric nonlinear control theory together with an approximation technique. The conditions under which an exact observer exists are derived. Some examples are given for which simulation tests assure a good performance even when the observer is connected to a control system.>

The problem of modeling flexible robots is considered. The dynamic model is obtained by using a generalized Lagrangian approach and by expanding in a limited number of terms the function describing the exact shape of bended beams constituting the robot. General properties of the models, as controllability, are then investigated. To manipulate the cumbersome formulae the SAM language MACSYMA has been extensively used.

The problem of controlling robots with rotary and flexible joints is considered. An adaptive control strategy based on the measurement of the position of the links and of the speed of the actuator is proposed. The results, tested by simulation, are satisfactory and can be justified considering a linearized model for the robot.

In this paper a program for generating the model of industrial robots in a symbolic form is presented. The program, called DYMIR, derives the motion equations of robots here considered as a chain of rigid bodies connected by suitable single degree-of-freedom (DOF) joints. This is transparent to the user and allows the symbolic calculation of dynamical models until twelve DOF and may take into account elasticity and transmission losses at the joints.