For ease of manufacture, axisymmetric components produced by processes such as forging, casting and moulding are often designed with a taper angle. This paper presents a family of devices for handling such components by their tapered portion. The devices are essentially finger tips, or jaws, to be fitted to standard scissor-type robot grippers. The jaws possess a three-dimensional profile constructed as a stack of v-shaped planar curves. The special jaw profile enables components of different diameters and taper angles to be gripped concentrically without calling for complex movements to reposition the gripper. The equations describing two categories of profile are derived and the optimum selection of profile parameters to yield compact jaws to grip components of a wide range of dimensions is discussed in the paper.

The paper considers the highest control level organization of a flexible manufacturing cell (FMS). The indeterminancy problem in Petri nets is discussed as well as a method for overcoming it by two control levels. The net is decomposed into individual robot nets and machines. A simple language for defining robot activation conditions is developed and used for defining knowledge base contents. A method for linking it with other control modules is given. Also, the solution performance is analysed.

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.

Initial development of a robotic meat cutting system based on force feedback control and continuous path planning is described. Forequarter beef cutting is attempted where each carcass processed will be compared to a database containing cut information for previously processed beef carcasses. Using the database information, cut start and end points can be defined along with initial path direction for each cut. A robot then drives a powered knife through the carcass utilising force feedback control to follow bone profiles, thus removing meat from the forequarter. An original cutting scheme suitable for robotic butchery of a beef forequarter is defined, along with a notation scheme for describing the cutting procedures.

This paper is concerned with the dynamic merit of robot manipulators and method for the optimization of manipulator dynamics in the case of an extremely bad design, which can be put into three categories: 1. Acceleration performance: minimize 2. Velocity performance: minimize 3. Comprehensive performance: minimize , and are the dynamics indices of API, VPI and CD PI under various conditions respectively.

The exchange algorithm is presented and a procedure is developed to solve this kind of Minimax problem. An example is discussed to illustrate the application of the optimization method. The large uniform magnitude of a joint relative driving torque provided by this dynamics optimization procedure will be made into a large work space and large torques.

A prototype robot system for automated handling of flexible electrical wires of variable length is described. The handling process involves the selection of a single wire from a tray of many, grasping the wire close to its end with a robot manipulator, and either placing the end in a crimping press or, for tinning applications, dipping the end in a bath of molten solder. This system relies exclusively on the use of vision to identify the position and orientation of the wires prior to their being grasped by the robot end-effector. Two distinct vision algorithms are presented. The first approach utilises binary imaging techniques and involves object segmentation by thresholding followed by thinning and image analysis. An alternative general-purpose approach, based on more robust grey-scale processing techniques, is also described. This approach relies in the analysis of object boundaries generated using a dynamic contour-following algorithm. A simple Robot Control Language (RCL) is described which facilitates robot control in a Cartesian frame of reference and object description using frames (homogeneous transformations). The integration of this language with the robot vision system is detailed, and, in particular, a camera model which compensates for both photometric distortion and manipulator inaccuracies is presented. The system has been implemented using conventional computer architectures; average sensing cycle times of two and six seconds have been achieved for the grey-scale and binary vision algorithms, respectively.

A computationally fast inverse kinematic scheme is derived which solves robot's end-effector (EE) trajectories in terms of joint trajectories. The inverse kinematic problem (IKP) is cast as a control problem for a simple dynamic system. The resulting closed-loop algorithms are shown to guarantee satisfactory tracking performance. Differently from previous first-order schemes which only solve for joint positions and velocities, we propose here new second order tracking schemes which allow the on-line generation of joint position + velocity + acceleration (PVA) reference trajectories for any computed torque-like controller in sensor-based robot applications. The algorithms do explicitly solve the IKP for both EE position and orientation. Simulation results for a six-degree-of-freedom PUMA-like geometry demonstrate the effectiveness of the scheme, even near singularities.

Attaching the milking machine to the cow is the last remaining major repetitive task that the worker in a modern milking parlour has to perform. Several groups of research workers are developing robotic systems for this purpose. The task for the robot of locating the cow's teats and attaching the machine is complicated by morphological differences between cows and the need to allow the cow freedom to move during the operation. This paper reviews the progress that has been made.

A partial review of some efforts in robotics research is presented. We identify two broad categories of work: one characterised by application-driven experimental engineering, the other by a more ‘scientific’ approach based on testing theoretical models through implementation. We argue that although the former represents some of the best practical results obtained to-date, this experiment-first-theory-later approach does not contribute to a homogeneous body of knowledge. If robotics is to make measured progress, sound theoretical ground is needed. We argue for a task-specific paradigm for future theoretical work founded on formal models. To this end, we present a general analysis of a sensory robotic system, and identify key elements that must be defined in any formal model before we can decide what sensory information is useful for a given task.

A new approach to redundant robots is presented. The problem of the multiple solutions of the inverse kinematic is solved by making a special distribution of robot external motions to the redundant number of joint motions. The distribution is made in such a way to separate the smooth transport motion from the relative motion which could be fast and have high acceleration.

This paper presents a collision-free motion planning method of two articulated robot arms in a three dimensional common work space. Each link of a robot arm is modeled by a cylinder ended by two hemispheres, and the remaining wrist and hand is modeled by a sphere. To describe the danger of collision between two modeled objects, minimum distance functions, which are defined by the Euclidean norm, are used. These minimum distance functions are used to describe the constraints that guarantee no collision between two robot arms. The collision-free motion planning problem is formulated as a pointwise constrained nonlinear minimization problem, and solved by a conjugate gradient method with barrier functions. To improve the minimization process, a simple grid technique is incorporated. Finally, a simulation study is presented to show the significance of the proposed method.

Inertial Measurement Systems (IMS) allow the position calculation of moving objects without requiring outside information. For years the inertial 3-D coordinate measuring technique has been subject to intense research in geodesy and autonomous navigation of land-, water-and airborne vehicles. Because of these areas of application inertially-based systems have been designed for long term measuring only. Here we discuss the requirements that are imposed on inertial sensors in order for them to be used for the calculation of positions of robots. The use of modern sensor technology, combined with strategies for error correction, can result in substantial advantages when calculating robot positions independently from load and environment.

A redundant robot manipulator has several certain or expected advantages over a nonredundant one. It is expected, among other capabilities, that the joints vary with constant velocities during the execution of those tasks which in a nonredundant manipulator require variable joint velocities. In this way, motion becomes more precise because of the elimination of errors associated with velocity change in joints. In this paper, it is shown that this expected advantage is not possible for all the joints, and that only as many joints as the degree of redundancy can have constant velocities.

The flexible structure of a robot multi-links manipulator can be either a side effect or, on the contrary, an essential feature. We present a fairly general model to derive the corresponding dynamic equations in quite a systematic and simple way. To this end, we use the Lagrange formulation with strain energy potential and Raleigh (dissipation) functions. The approach can incorporate torsional deformation and aerodynamic friction, and it applies easily to robots working in the sea. The trajectory control appears to be one in the presence of model imprecision, and a slightly modified version of the classical sliding control technique is utilized to design the tracking control of the manipulator. Then we introduce the time-varying inertia link device (carried out by means of sliding masses) which we suggested in earlier work, and we show how it can be used to improve the tracking control scheme above. This paper contributes new ideas concerning flexible multi-links arms and active inertia links.

Building Management Systems and Home Automation are, at present, active areas of research and development. One of the unsolved problems within this field is that of Occupant Location within a premises. Computer vision systems are, as yet, too expensive and still not entirely adequate to monitor occupation from every room in a building. The use of existing movement sensors is a cost effective solution but has the disadvantages of not detecting people who are stationary for some time, or giving any indication of how many people are in a room.

This paper addresses the problem of using the collaborative sum of these simple movement sensors in a temporal reasoning scheme to deduce room occupation.