This paper presents a new calibration method for industrial robots. The calibration method is based on a combination of inclinometer and LVDT measurements and is very simple to use. The inclinometers measure the deviation from the gravity direction of a measurement rod and the LVDT sensor measures the length of the rod. The inclinometers can be used without any pre-calibration and the whole equipment is inexpensive, portable and robust.

We propose an event-driven algorithm for the control of simple robot assembly problems based on noncooperative game theory. We examine rigorously the simplest setting – three bodies with one degree of freedom and offer extensive simulations for the 2 DOF extension. The initial analysis and the accompanying simulations suggest that this approach may indeed, offer an attractive means of building robust event driven assembly systems.

Herein is proposed a concise algorithmic procedure for deriving a minimum l∞-norm solution of the system of consistent linear equations Ax=b, where A is a m×n matrix, b is given as a m×1 vector and x is a n×1 unknown vector. The proposed algorithm is developed based on the geometrical analysis of the characteristics of the minimum infinity-norm solution. The proposed algorithm is well-structured so that it may be implemented easily through simple linear algebraic manipulation. For the case of n>m, the basic idea of the method is extended to finding internally mapped vertices when a n dimensional polytope is transformed into m dimensional polytope through consistent linear mapping A. The proposed method is applied to the task velocity analysis for robot manipulators with joint velocity constraints.

In this paper, the analysis of manipulability of robotic systems comprised of multiple cooperating arms is considered. Given bounds on the capabilities of joint actuators for each robot, the purpose of this study is to derive the bounds for task velocity achievable by the system. Since bounds on each joint velocity form a polytope in joint-velocity space and the task space velocity is connected with joint velocity through Jacobian matrices of each robot, the allowable task velocity space, i.e. velocity workspace, for multiple cooperating robot system is also represented as a polytope which is called manipulability polytope throughout this paper. Based on the fact that the boundaries of the manipulability polytope are mapped from the boundaries of allowable joint-velocity space, slack variables are introduced in order to transform given inequality constraint given on joint velocities into a set of normal linear equalities in which the unknowns of the equation are composed of the vertices of manipulability polytope, vectors spanning the null space of the Jacobian matrix, and the slack variables. Either redundant or nonredundant cooperating robot systems can be handled with the proposed technique. Several different application examples including simple SCARA-type robots as well as complex articulated robot manipulators are included, and, under the assumption of firm grip, it will be shown that the calculated manipulability polytope for cooperating robot system is actually the intersection of all the manipulability polytopes of every single robot which is hard to be derived through geometrical manipulation.

Industrial parts can be fed (oriented) using a sequence of fixed horizontal pins to topple the parts as they move past on a conveyor belt. We give an algorithm for designing a sequence of such pins for a given part. Given the n-sided convex polygonal projection of a part, its center of mass and frictional coefficients, our O(n2) algorithm computes the toppling graph, a new data structure that explicitly represents the mechanics of toppling, rolling, and jamming. We verify the toppling graph analysis with experiments. Our O(n3n) design algorithm uses the toppling graph to design a sequence of pin locations that will cause the part to emerge in a unique orientation or to determine that no such sequence exists.

SYMPOSIUM ON ROBOTICS – PRESENT AND FUTURE

CALL FOR PAPERS

The above event will be held on March 24–26, 2002, in Pittsburgh, Pennsylvania (USA) in the context of the joint meeting of the World Organisation of Systems and Cybernetics (WOSC) and of the International Institute for General Systems Studies (IIGSS) (12th WOSC Congress and 4th IIGSS Workshop).

SYMPOSIUM ON ROBOTICS – PRESENT AND FUTURE

CALL FOR PAPERS

The above event will be held on March 24–26, 2002, in Pittsburgh, Pennsylvania (USA) in the context of the joint meeting of the World Organisation of Systems and Cybernetics (WOSC) and of the International Institute for General Systems Studies (IIGSS) (12th WOSC Congress and 4th IIGSS Workshop).