Order-picking, i.e. arranging work-pieces of different types on a pallet, which is nowadays often carried out manually, will in future be more and more automated for economic reasons. The industrial robot in combination with an intelligent gripper, a supporting palletizing and order-picking software and a suitably designed periphery will permit fully automated order-picking. The Fraunhofer-Institute for Manufacturing Engineering and Automation (F.R.G.) has developed such a system which takes advantage of the arrangement of the work-pieces in the compartment stack and simultaneously grips the work-pieces that are then arranged in a pattern on a pallet.

The mass balancing of robotic manipulators has been shown to have favorable effects on their dynamic characteristics. In actual practice, however, since conventional manipulators have flexibility at their joints, the improved dynamic properties obtainable for rigid manipulators may be influenced by those joints flexibilities. This paper investigates the effects of the joints flexibility on the dynamic properties and the controlled performance of a balanced robotic manipulator. The natural frequency distribution and damping characteristics were investigated through frequency response analyses. To evaluate the dynamic performance a series of simulation studies of the open-loop dynamics were made for various trajectories, operating velocities, and joint stiffnesses. These simulations were also carried out for the balanced manipulator with a PD controller situated inside the motor control loop. The results show that, at low speed, the joints flexibility does but little influence the performance of the balanced manipulator, but at high speed it tends to render the balanced manipulator susceptible to vibratory motion and yields large joints deformation errors.

The main objective of this work is to study the performance of a flexible single hub-arm system. The equations of motion are derived using the extended Hamilton principle. The Liapunov functional is used as a condition for the stability analysis. The Liapunov functional is considered as the sum of the internal energy of the flexible beam. The required drive torque was obtained directly through the solution of the inverse dynamic problem. Although the flexible link is nonminimum phase in nature, the use of Liapunov and the PD controller guarantee the causality for the stable case. The effects of tip mass as well as its inertia in the case of stable and asymptotic stable systems were investigated to ensure the validity of this procedure.

In this paper we present the results obtained from the implementation of a robust position/force controller on a two-degree-of-freedom direct drive robot. The controller is based on the theoretical work presented in references 1 & 2, which guarantees Globally Uniformly Ultimately Bounded (GUUB) position tracking error and bounded force tracking error. The controller accomplishes this stability result in spite of robot model uncertainty and only requires; joint position and velocity measurements, end-effector force measurements, and bounds on the model parameters. Experimental results described in this paper serve to verify the theoretical claims.

The use of ultrasonic range transducers is an inexpensive method of obtaining information about the environment surrounding a robotic System. However, ultrasonic ranging suffers from various shortcomings, one of the major being the production of unreliable data caused by specular reflection.

This work presents an original approach to overcoming the problem of unreliable ultrasonic range data which is caused by specular reflection of the ultrasonic beam. The approach is shown to discriminate between reliable and unreliable data, thus enhancing the role of the ultrasonic range transducer in robotic applications.