Song, S., Waldron, K. & Kinzel, G.L. 1985, 'Computer-aided Geometric Design Of Legs For A Walking Vehicle', Mechanism And Machine Theory, vol. 20, no. 6, pp. 587-596.
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Waldron, K., Wang, S. & Bolin, S. 1985, 'A Study Of The Jacobian Matrix Of Serial Manipulators', Journal Of Mechanisms Transmissions And Automation In Design-transactions Of The ASME, vol. 107, no. 2, pp. 230-238.
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Waldron, K.J., Wang, S.L. & Bolin, S.J. 1985, 'STUDY OF THE JACOBIAN MATRIX OF SERIAL MANIPULATORS.', Journal of mechanisms, transmissions, and automation in design, vol. 107, no. 2, pp. 230-238.
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Inversion of the Jacobian matrix is the critical step in rate decomposition which is used to solve the so-called 'inverse kinematics' problem of robotics. This is the problem of achieving a coordinated motion relative to the fixed reference frame. A general methodology is presented for formulation and manipulation of the Jacobian matrix. The formation is closely tied to the geometry of the system and lends itself to simplification using appropriate coordinate transformations. This is of great importance since it gives a systematic approach to the derivation of efficient, analytical inverses. The method is also applied to the examination of geometrically singular positions. Several important general results relating to the structure of the singularity field are deducible from the structure of the algebraic system.
Bolin, S.J. & Waldron, K.J. 1985, 'SIMULATION OF A ROBOT MANIPULATOR COORDINATED BY A GEOMETRICALLY SIMPLIFIED RATE CONTROL ALGORITHM.', Proceedings - OSU Applied Mechanisms Conference (Oklahoma State University).
An important concept in the development of manipulator coordination algorithms is the Jacobian matrix. The Jacobian is used to relate the velocity state of the robot hand to the required joint rates. In this paper, coordinate transformation is used to simplify the analytical decomposition of the Jacobian matrix. An analytical decomposition of the Jacobian is employed to determine the joint rate equations and also the singularity conditions for the Unimation PUMA 560 robot.
Pery, A., Gardner, J.F. & Waldron, K.J. 1985, 'DESIGN AND TESTING OF A HIGH PERFORMANCE HYDRAULIC POWER SYSTEM FOR A LEGGED LOCOMOTION APPLICATION.', Proceedings of the American Control Conference, pp. 730-736.
The requirements imposed on the actuation system of an energy-autonomous, six-legged walking vehicle are unique and rigorous. The analysis, design, and testing of such an actuation system for the adaptive suspension vehicle (ASV) at Ohio State University is presented. Special attention is given to the synthesis of the general system configuration, which is a pump-controlled hydraulic system. The selection, design an testing of individual components and systems are discussed. The system developed and designed for the ASV has reasonably large bandwidth, compatible with equivalent familiar valve control systems. This system, although designed for a rather unique application, may eventually find its way into more conventional applications, such as in the heavy-duty robotics field.
Pham, D.T. & Dissanayake, G. 1985, 'FEASIBILITY STUDY OF A VIBRATORY SENSOR FOR LOCATING 3-D OBJECTS.', Proceedings of the International Machine Tool Design and Research Conference, pp. 201-211.
A novel sensor is investigated which is intended to be mounted at the wrist of a robot to enable it to determine the co-ordinates of a part it has picked up from a stack or tray. The device operates by letting the part vibrate about two orthogonal axes and measuring its inertia-dependent instantaneous velocities and angles of vibration. The mathematical procedures for extracting position and orientation data from these measurements are described. The results of computer simulations carried out to determine guidelines for the design of the device are presented and discussed.
Two inertia-based sensors for determining the position and orientation of three-dimensional objects are described. One of them involves letting the objects vibrate about two orthogonal axes simultaneously and measuring the angles and velocities of vibration at various instants of time. In the other sensor, the objects are also vibrated about two axes but the vibrations are performed sequentially and the frequencies of vibration are measured. The mathematical procedures for obtaining the position and orientation of the objects from the measurements are outlined for the second sensor. Results of the computer simulations carried out to assess the feasibility of the latter are presented.
A compromise solution to the problem of economically feeding parts to industrial robots is investigated. The parts are neither accurately presented as in the case of traditional feeding equipment nor jumbled up as in the case of bin-picking machines. Instead, they are semi-ordered into stacks or trays and then unloaded by the robots as needed. The robots are to be equipped with a novel sensor fitted to their wrists for determining the exact coordinates of the parts they have picked up. The device operates by letting the parts vibrate about three orthogonal axes and measuring their inertia-dependent natural frequencies of vibration. The mathematical procedures for extracting position and orientation data from those measurements are described. The results of computer simulations carried out to determine guidelines for the design of the device are presented and discussed.
Song, S.M., Lee, J.K. & Waldron, K.J. 1985, 'MOTION STUDY OF TWO AND THREE DIMENSIONAL PANTOGRAPH MECHANISMS.', Proceedings - OSU Applied Mechanisms Conference (Oklahoma State University).
Coupling of vertical, horizontal and rotory motions in manipulators slows down calculating speed for real time control and lowers system energy efficiency. Pantograph mechanisms are being used as manipulators to remove the coupling of motion. Methods which are used to determine the workspace of pantograph type manipulators are illustrated in an example. Some aspects of structural design are also discussed.
Song, S.M., Lu, F.H. & Waldron, K.J. 1985, 'NUMERICAL METHOD IN DETERMINATION OF THE SHORTEST CRANK IN FOUR POSITION BURMESTER SYNTHESIS.', Proceedings - OSU Applied Mechanisms Conference (Oklahoma State University).
A numerical implementation based on the Newton-Raphson method of solving seven nonlinear equations is presented. A set of eight simultaneous and nonlinear equations is able to eliminate the spurious solutions which give incorrect geometry, and the spurious solutions which have wrong signs of angles are detected by the computer after convergence. The accurate length and position of the shortest crank can then be determined by a few trials.
Algorithms are presented which permit efficient computation of manipulator workspace volumes, their centroids, moments of inertia and, if necessary, higher moments. These algorithms have been implemented in an interactive computer graphic program permitting rapid evaluation of designated manipulator regional structure geometries. Positions of centroids and moments of inertia can be used as figures of merit characterizing the shape of the workspace.
The control of a legged locomotion system over uneven terrain requires a new approach to coordination. The system has a high degree of static indeterminacy and, because of the stiffness of the structural and actuation systems, has stability problems if position-velocity control is used. The problem has many similarities to that of grasping and manipulating an object in a multifingered hand. The stability problem is removed by controlling actuator force directly, but the necessary computations can be prohibitive. A solution is presented which is moderate in its computational requirements. It is based on an assumption of zero foot interaction forces in the horizontal plane.
The interaction of the mechanics of a mobile platform with control and sensing hardware and software is important to performance in robotic applications. In this paper the basic principles involved will be reviewed, and new material on comparative characterizations will be presented. The application of those principles to a specific example: the Adaptive Suspension Vehicle, will be presented.
Waldron, K.J., Brown, T.F., Vohnout, V., Kinzel, G. & Srinivasan, K. 1985, 'TWO EXPERIMENTS ON LEGGED LOCOMOTION.', Proceedings - OSU Applied Mechanisms Conference (Oklahoma State University).
This paper contains a discussion of the OSU Monopod and the DUWE (Dynamic Unpowered Walking Experiment). These devices were constructed to experimentally verify ideas relating to legged locomotion with low specific resistance. These ideas were incorporated into the design of the Adaptive Suspension Vehicle. The DUWE was also used to explore the mechanics of ballistic leg return and the energetic interactions of the legs and body of a multi-legged machine.
Some aspects of the mechanical and geometric design of the adaptive suspension vehicle are presented. In particular, there is an emphasis on aspects of the leg design and vehicle geometry, which affect the ability of the vehicle to operate on steep grades or to cross obstacles. A mechanism that maintains the attitude of the foot approximately parallel to the body is described. Geometric aspects of maintaining static stability on steep grades are discussed. Geometric and gait sequence aspects of crossing severe obstacles are also discussed.