A haptic interface is a computer-controlled mechanism designed to detect motion of a human operator without impeding that motion, and to feed back forces from a teleoperated robot or virtual environment. Design of such a device is not trivial, because of the many conflicting constraints the designer must face.

As part of our research into haptics, we have developed a prototype planar mechanism. It has low apparent mass and damping, high structural stiffness, high force bandwidth, high force dynamic range, and an absence of mechanical singularities within its workspace. We present an analysis of the human-operator and mechanical constraints that apply to any such device, and propose methods for the evaluation of haptic interfaces. Our evaluation criteria are derived from the original task analysis, and are a first step towards a replicable methodology for comparing the performance of different devices.

The programming of robots forms a popular research topic. Different approaches for developing ideal robot programming system have already been proposed. They all attempt to raise the level of abstraction of the robot programming system. They differ, however, to a great extent in the stage of maturity they have reached to become eligible for industrial application. “Explicit robot programming languages”, in which every robot action has to be specified explicitly, can be said to be ready for industrial application. Therefore a detailed analysis is made of the requirements that are put on the class of “explicit robot programming languages”. Their basic composing elements are recognized and discussed in detail.

A special-purpose robot for prostatectomies has been developed. Details of the robot mechanism, control system and human/computer interface (HCI) are discussed with special emphasis on software methods to ensure system safety. The clinical application of the system is described and software requirements for operating-theatre use are indicated. These requirements include safe error recovery, facilitation of reliable surgical procedures, and an effective HCI.

In the paper a formal model is presented of the discrete control of a bile robot moving over a plane. The model synthesis has been directed in such a way as to justify the use as a controller of the automaton with internal and external parameters. It has been shown that, while controlled in discrete time the mobile robot performance can be expressed by a one-sidely optimized tree of a two-person extensive game. The tree, after transforming into the form of the state diagram of an automaton, serves as a basis for the synthesis of the automaton with internal and external parameters playing the role of a controller. A method is presented of synthesizing an automaton of this type, being a hardware realization of the mobile robot controller.

Robotic assembly systems offer tremendous promise for the flexible assembly automation but present a variety of complex research issues due to the positioning inaccuracy of the manipulator, dimensional variation of mating parts and their physical interactions. This paper provides an up-to-date survey of researches in robotic assembly with emphasis on parts mating technology. Depending upon the mating strategy, presently available methods of performing precision assembly operations are classified and their advantages and limitations are discussed from the view points of the system complexity, adaptability and reliability. The performance variables such as the mating speed, positioning error absorbing capability and applicability are compared in some details for various assembly methods.

A new approach to represent assembly called state matrix representation and an algorithm for automatic robot assembly planning based on this representation is proposed. The state matrix representation of assembly is configured by considering the inter-relationships of parts and objects involved in the initial and the goal structures. Thanks to this new representation, the planning lgorithm is straightforward and can be easily and efficiently implemented with simple matrix manipulation. Unlike other planning methods, the actions involved in the assembly process are not defined in advance but are generated at planning time. The syntax of actions are designed so that while directly reflecting the semantics of actions, they can be easily manipulated by the planner. Two examples of how to plan an assembly based on this representation are given in the paper.

A new robot system has been introduced which was designed to seal the seams of car body panels. The system has nine degrees of freedom, and includes the following features: (1) A seam tracking servo using a solid-state TV camera is mounted at the robot hand to compensate for the seam deviations. (2) The robot arm is equipped with a flexible mechanism at the wrist to provide a wide working range for the seal nozzle. (3) A two axis orthogonal robot carrier is provided to make the robot follow the work on an indexed conveyor during the sealing operation. This paper deals with the structure and operation of the system and presents test results obtained on a sealing line.

Complex tasks that need to be performed through teleoperation led to the development of multifinger robot hands. A dextrous master is a multi-DOF controller which is worn by the operator in order to teleoperate these anthropomorphic hands. Force feedback is very useful when there is interaction with the environment. Providing force feedback to dextrous masters is an area of active research. We outline some of the human factors that influence the design of such masters. Of obvious importance is the hand geometry and the desired number of degrees of freedom. Additional criteria relate to the force perception of the hand. Finally, the man-machine impedance is of importance, since at the man/machine interface there are two impedances acting in series. One is the effective impedance of the human operator holding the master controller, the second is the impedance of the master controller being manipulated.

Interpolation of a robot joint trajectory is realized using trigonometric splines. This original application has several advantages over existing methods (e.g. those using algebraic splines). For example, the computational expense is lower, more constraints can be imposed on the trajectory, obstacle avoidance can be implemented in real time, and smoother trajectories are obtained. Some of the spline parameters can be chosen to minimize an objective function (e.g. minimum jerk or minimum energy). If jerk is minimized, the optimization has a closed form solution. This paper introduces a trajectory interpolation algorithm, discusses a method for path optimization, and includes examples.