Manipulators for laser welding need to be capable of tracking a specified seam with an accuracy in the order of 0.1 mm at speeds exceeding 100 mm/s. A framework for realistic dynamic simulations has been set up to study the applicability of industrial robotic manipulators for such tasks. These simulations describe the closed loop system of the mechanical robot arm and the (digital) controller. ...

The increasing intelligence and autonomy of modern robot systems requires new and powerful man-machine-interfaces. For example, a robot' s capability to autonomously recover from error situations corresponds with dynamic adjustments of robot plans during execution. This makes it difficult for an operator to predict and understand the behaviour of the machine. Explanations and descriptions of wh...

State estimation of a flexible industrial manipulator is presented using experimental data. The problem is formulated in a Bayesian framework where the extended Kalman filter and particle filter are used. The filters use the joint positions on the motor side of the gearboxes as well as the acceleration at the end-effector as measurements and estimates the corresponding joint angles on the arm s...

evolving models have found applications in many real world systems. in this paper, potentials of the evolving linear models (elms) in tracking control design for nonlinear variable structure systems are introduced. at first, an elm is introduced as a dynamic single input, single output (siso) linear model whose parameters as well as dynamic orders of input and output signals can change through ...

This paper presents a weighted path planning approach for a light weight robot coming into compliant contact with the environment, as well as robot‐ environment interaction enabled impedance control. Using a joint torque sensor, Cartesian impedance control is introduced to realize the manipulator compliance control. Then the weighted path planning approach is de...

Integrated structure control design of a two-link flexible robot arm is investigated in this article. The whole arm consists of two flexible links, a fixed joint, a moving joint, and a tip load. The arm is driven by the torque motors at the two joints to reach predefined tip positions and to suppress residual flexural vibrations. The links of the arm are modeled using the finite element method ...

A Space Free-Flying Robot (SFFR) includes an actuated base equipped with one or more manipulators to perform on-orbit missions. Distinct from fixed-based manipulators, the spacecraft (base) of a SFFR responds to dynamic reaction forces due to manipulator motions. In order to control such a system, it is essential to consider the dynamic coupling between the manipulators and the base. Explicit d...

The adaptive control of robot manipulators has been presented as a solution for dealing with uncertainty and variation of the mass properties. Although these systems are nonlinear, globally stable tracking has been demonstrated both analytically and supported through experiments [1]. The key to these results has been the linear dependence of the model on the unknown parameters and, in many case...

A framework for Iterative Learning Control (ILC) is proposed for the situation when the ILC algorithm is based on an estimate of the controlled variable obtained from an observer-based estimation procedure. Under the assumption that the ILC input converges to a bounded signal, a general expression for the asymptotic error of the controlled variable is given. The asymptotic error is then exempli...

This paper addresses the problem of impedance control for flexible joint robots based on a singular perturbation approach. Some aspects of the impedance controller, which turned out to be of high practical relevance during applications are then addressed, such as the implementation of nullspace stiffness for redundant manipulators, the avoiding of mass matrix decoupling and the related design o...