In this paper a new method is presented for solving the inverse kinematics of free-floating space manipulators. The idea behind the method is to move the space manipulator along a path with minimum dynamic disturbance. The method is proposed to use the manipulator Jacobian instead of the generalized Jacobian of the spacecraft-manipulator system. This is based on the simple fact that, if the space manipulator moves along the so-called Zero Disturbance Path (ZDP), the spacecraft is immovable. As a result, the space manipulator can in this case be treated as a terrestrial fixed-based manipulator. Hence, the motion mapping between the joints and the end-effector can be described directly by the manipulator Jacobian. In the case that the ZDP does not exist, it can be shown that the solutions obtained by the proposed method provide a path with minimum dynamic disturbance.

A single-loop spatial mechanism kinematically becomes an open robot, if we separate the grounded joint of the input link which may then be considered as the end effector of the robot. Any position of the end-effector within the workspace of such an open robot can be reached via a number of different configurations of the links. These configurations are called “branches” of the open robot for that particular position of the end effector.

If the open robot is now stretched to a limiting position by a force exerted on the end effector, all the possible branches of the mechanism approach each other. When they become coincident, they form the “limiting configuration”. Any two related branches are at opposite sides of the limiting configuration. From the relationship between the links in th elimiting configuration and in related branches, conditions for aviodance of branching of the original closed-loop mechanism can be obtained. This is necessary in order to assure that a set of consistent relative displacements are specified for the open robot to move displacements are specified for the open robot to move toward the desired end-effector position without jumping from one branch to another. As for the closed-loop mechanism, open robot branching aviodance ensures that a desired sequence of positions of a particular floating link in the loop will be generated without changing the branch of the link configuration.

In this paper, the above approach is applied to RSSR, RRSC, RRSRR, RRRRRRR and RPCRRR spatial closed-loop motion-generator mechanisms and the corresponding conditions for aviodance of branching in the synthesis of the mechanisms are derived.

This special issue in Robotica contains papers from Japanese authors on microrobots and distributed microactuators. Advances in technology made possible progress in the realm of small but complicated microsystems that include different elements, such as sensors, circuits and actuators. Microsystems are also called micromachines or microelectromechanical systems (MEMS); microsystems which move like insects are termed microrobots.

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.

After reviewing the conference topics, the author discusses the technical potential of automation in the wider aspects of technical innovation. The next topic is concerned with automation and the world economy in general, and that in developed countries in particular. Some comments are then made about the manufacturing prospects in the U.K. and their relationships with education and training in the relevant fields. Finally, the inauguration of the Advanced Manufacturing Technology Chair at the University of Salford is described in the context of industry-education problems.

This paper proposes and demonstrates a method toobtain macroscopic work out of distributed microactuatorsfabricated by IC-compatible micromachiningprocesses. We have coordinated the simple and smallmotion of microactuators in order to perform a task. Theconcept and a control scheme are discussed first. In orderto show the feasibility, the fabrication and operation ofarrayed microactuators for conveyors are described. One uses thermally driven cantilevers and the other uses controlled air flow from micronozzles to carry flat objects.

Human posture is the co-operation of parts of the body to perform a task. This organization is self optimised by the operator to minimize strain and pain and maximize efficiency. This problem is formulated as a problem of inverse kinematic of a redundant robot. Constraints are imposed by the visual and manual task, and criteria may be modified in relation to operator motivation and tiredness. An interactive graphical software is designed to teach the postural problem and as an ergonomic aid.

Let P = {p1, …,pn} and Q = {q1,…,qm} be two simple polygons in the plane with non-intersecting interiors, the vertices of which are specified by their cartesian coordinates in order. The translation separability query asks whether there exists a direction in which P can be translated by an arbitrary distance without colliding with Q. It is shown that all directions that admit such a motion can be computed in O(nlogm) time, where n > m, thus improving the previous complexity of O(nm) established for this problem. In designing this algorithm a polygon partitioning technique is introduced that may find application in other geometric problems.

The algorithm presented in this paper solves a simplified version of the grasping problem in robotics. Given a description of a robot hand and a set of objects to be manipulated, the robot must determine which objects can be grasped. The solution given here assumes a two-dimensional world, a hand without an arm, and grasping under translation only.