A method for trajectory control in the joint space is presented. An acceleration profile is proposed for each segment of the trajectory. After a twofold integration a position trajectory is obtained with advantageous characteristics. The position trajectory is completely dynamically balanced; it exhibits continuity up to the third derivative of the position. This way, minimum requirements are imposed on the actuators. The technique delivers predictable results since the trajectory deviates only slightly from a straight line connection between successive joint coordinates. Very limited computational effort is required.

Robot intensiveness in the manufacturing industry is growing rapidly, but the construction industry has been slow to capitalise on the array of robotic technology now available. An attempt is made to indentify various robot ensembles that may prove economically viable in building construction, and to configure these in such a way that particular characteristics of robot work methods are used to maximum advantage within the constraints of the construction environment.

Manipulator joint trajectories are planned to make an arbitrary cost function as good as possible in consideration of physical constraints based on kinematics and dynamics of a manipulator system. An algorithm presented in this paper is an iteratively improving method using the local controllability of B spline. It can be also applied to the case that some points are specified and joint trajectories must pass through those points. This algorithm is applied to an example of trajectory planning of a manipulator with two links and two degrees of freedom.

A method has been developed for accurately determining the differential movement of known objects from multiple camera views. The method has been applied to a robot System to find the repeatability and accuracy of the robot in both rotational and translational terms and also for tracking an object using visual feedback.

The problem of finding an allowable object trajectory for a cooperating two-robot system is investigated. The purpose is to move an object from one point to another by firmly grasping it at two different points using two robotic hands. The major difficulty is caused by the fact that, unless the robots have true six degrees of freedom, the trajectories the object can follow are severely limited and, in general, are difficult to find. The method proposed in the paper is based on reformulating the problem as a nonlinear optimization problem with equality constraints in terms of the joint variables. The optimization problem is then solved numerically on a computer. The solution automatically gives the corresponding joint variable trajectories as well, thus eliminating the need for solving the inverse kinematic problem. The method has been successfully applied to a real experimental system.

The degree to which a binary tactile (or visual) image matches the original object is limited by the resolution of the sensor array. Given this fundamental limitation it is still possible to minimize the error in the image formed by the interconnection of the centers of activated sensors along the object's edge. This is achieved by a suitable choice of the physical size of each sensor within the limits of the pixel size. An empirical investigation shows that normally a sensor area of about 50% of the square of the resolution yields an optimal result.

At present, the procedure which is most widely used to identify an object consists of displacing its image in order that it be as close as possible to a reference pattern, and then to make a decision based upon the value of an Euclidean distance. This decision may be either in a deterministic framework or in a statistical one. The transformations so involved are translation and rotation. It is shown that, if one takes for granted the invariance of the amount of information involved by the object considered as an informational source, then there is another class of transformations, referred to as deformation, which should be also taken into account. The question is examined, and its consequences in the design of artificial vision are outlined in both the deterministic and stochastic cases.

One way to increase the flexibility (or versatility) of manipulators is to use links with time varying inertia. One can then control both the joint torques and the inertias of the links therefore more pliancy in the practical utilisation of the arm. The paper deals with the Lagrangian formulation of the corresponding inertia control problem which can be considered either in open loop or in closed loop form. The general equations are derived and it is shown that one so obtains a set of uncoupled Ricatti differential equations which define the dynamics of the structural inertias. Problems related to stabilization and to structural parameter uncertainty are also considered.

In the paper we present system-theoretic descriptions of the robot's kinematics models, in a discrete and discretized workspace. For those descriptions, the problem of planning collision-free trajectories of motion is stated and represented as a classical problem of optimizing the behaviour of dynamical system.

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.

A low cost tactile sensor using commercially available conductive silicone rubber has been developed. It comprises a two dimensional array arranged in 3 mm centre-to-centre distance. Each sensor element has a zero-force resistance of about 0.3 kohm and it has a logarithmic characteristic curve of resistance versus force. An 8 × 8 prototype tactile sensor array over an area of 3 cm × 3 cm has been fabricated and mounted on the gripper of a robot for testing and evaluation. The associated software has also been developed. The limitations of the sensor are also discussed.

This paper presents a complete derivation of the combined flexural-joint stiffness matrix and the elastic deformation field of flexible manipulator arms treated in a three-dimensional fashion. The stiffness properties are derived directly from the differential equations used in the engineering beam theory. The expressions developed here can readily be used in the modeling, control and design of light weight flexible robot manipulators. A two-link arm is used to formulate these expressions and the results can be generalized to n–link manipulators. The stiffness matrix for a robotic link element in 3-D is of the order of 12 X 12, and for an n–link robotic arm the total elemental and system stiffness matrices will be of the order of the (12n X 12n) and 6(n + 1) X 6(n + 1), respectively.

This paper describes a novel tactile sensor array designed to provide information about the material constitution and shape of objects held by a robot manipulator. The sensor is modeled on the thermal touch sense which enables humans to distinguish between different materials based on how warm or cold they feel. Some results are presented and methods of analysing the sensor data are discussed.

In a 1985 issue of this journal, Kusiak presented a formulation of the single period station loading problem related to planning of Flexible Manufacturing Systems. This note makes several observations about this formulation and the linear programming solution technique used. Possible variations and some structural properties of the fomulation are highlighted.

When fitting contacts to connectors, the flexibility of the wires and the irregularity of the contact shapes have proved to be the greatest obstacles in developing automation. Within the framework of the present project, two methods for fitting irregular and flexible parts have been developed, both using industrial robots supported by vibrating tools. For theoretical analysis the irregular, flexible part is mathematically idealized. The tests are carried out with these idealized parts and crimp contacts. These tests proved that the vibration method is suitable for fitting irregular, flexible parts.

This paper presents a method for automatic forming and solving dynamic equations of motion of manipulator with elastic joints and rigid segments. For the minimal configuration of a cylindrical manipulator the numerical integration of these equations is performed, and vibrations in the joints are obtained as dynamic errors with respect to the prescribed trajectory.