Adaptive robust synchronized control for cooperative robotic manipulators with uncertain base coordinate system

Author(s):  
Anbang Zhai ◽  
Jin Wang ◽  
Haiyun Zhang ◽  
Guodong Lu ◽  
Howard Li
Robotica ◽  
1995 ◽  
Vol 13 (6) ◽  
pp. 575-581
Author(s):  
Siamak Vahidi ◽  
Kazem Kazerounian

SummaryIn the computational kinematics of robotic manipulators, accuracy and sensitivity of the results are highly dependent on the choice of the coordinate system, the metric system, and the appropriateness of performance evaluation measure. In this paper, these undesired sensitivities are examined and suitable performance criteria are developed to eliminate the coordinate system and metric system dependencies, and adverse numerical effects associated with them. Also a new formulation for the Jacobian matrix, joint velocities, and hand velocities, based on the Euler angles, is developed. This formulation, further improves numerical accuracy of the computations. Numerical experiments are included.


2014 ◽  
Vol 124 ◽  
pp. 149-161 ◽  
Author(s):  
Dongya Zhao ◽  
Quanmin Zhu ◽  
Ning Li ◽  
Shaoyuan Li

1989 ◽  
Vol 111 (4) ◽  
pp. 482-487 ◽  
Author(s):  
K. Kazerounian ◽  
G. Z. Qian

A kinematic calibration model for serial robotic manipulators is presented. This model is based on the zero position analysis method, and is not prone to the difficulties encountered in case of parallel or near parallel joints when using joint coordinate system notations. The convergence and effectiveness of the model are demonstrated by numerical simulations.


Author(s):  
Chin-Hsing Kuo ◽  
Jian S. Dai

An intuitive approach for the structural synthesis of serial robotic manipulator subject to specific motion constraints is presented in this paper. According to the required f-DOF αRβT motion of the end-effector, for f = 2, 3, … or 6 and α, β = 0, 1, 2 or 3, all feasible serial-type robot structures can be systematically generated via the proposed method. The approach begins at the enumeration of joint connectivity, proceeds with the assignment of joint types, and continues by the consideration of motion constraints for the robot. A couple of examples, including the synthesis of the 3-, 4- and 5-DOF serial manipulators, are furnished for illustration. It shows that this method is especially exploitable when the end-effector is required to be immovable in certain orientations or directions with respect to either local coordinate system or global coordinate system. The result is particularly beneficial for practical industrial applications.


1975 ◽  
Vol 26 ◽  
pp. 87-92
Author(s):  
P. L. Bender

AbstractFive important geodynamical quantities which are closely linked are: 1) motions of points on the Earth’s surface; 2)polar motion; 3) changes in UT1-UTC; 4) nutation; and 5) motion of the geocenter. For each of these we expect to achieve measurements in the near future which have an accuracy of 1 to 3 cm or 0.3 to 1 milliarcsec.From a metrological point of view, one can say simply: “Measure each quantity against whichever coordinate system you can make the most accurate measurements with respect to”. I believe that this statement should serve as a guiding principle for the recommendations of the colloquium. However, it also is important that the coordinate systems help to provide a clear separation between the different phenomena of interest, and correspond closely to the conceptual definitions in terms of which geophysicists think about the phenomena.In any discussion of angular motion in space, both a “body-fixed” system and a “space-fixed” system are used. Some relevant types of coordinate systems, reference directions, or reference points which have been considered are: 1) celestial systems based on optical star catalogs, distant galaxies, radio source catalogs, or the Moon and inner planets; 2) the Earth’s axis of rotation, which defines a line through the Earth as well as a celestial reference direction; 3) the geocenter; and 4) “quasi-Earth-fixed” coordinate systems.When a geophysicists discusses UT1 and polar motion, he usually is thinking of the angular motion of the main part of the mantle with respect to an inertial frame and to the direction of the spin axis. Since the velocities of relative motion in most of the mantle are expectd to be extremely small, even if “substantial” deep convection is occurring, the conceptual “quasi-Earth-fixed” reference frame seems well defined. Methods for realizing a close approximation to this frame fortunately exist. Hopefully, this colloquium will recommend procedures for establishing and maintaining such a system for use in geodynamics. Motion of points on the Earth’s surface and of the geocenter can be measured against such a system with the full accuracy of the new techniques.The situation with respect to celestial reference frames is different. The various measurement techniques give changes in the orientation of the Earth, relative to different systems, so that we would like to know the relative motions of the systems in order to compare the results. However, there does not appear to be a need for defining any new system. Subjective figures of merit for the various system dependon both the accuracy with which measurements can be made against them and the degree to which they can be related to inertial systems.The main coordinate system requirement related to the 5 geodynamic quantities discussed in this talk is thus for the establishment and maintenance of a “quasi-Earth-fixed” coordinate system which closely approximates the motion of the main part of the mantle. Changes in the orientation of this system with respect to the various celestial systems can be determined by both the new and the conventional techniques, provided that some knowledge of changes in the local vertical is available. Changes in the axis of rotation and in the geocenter with respect to this system also can be obtained, as well as measurements of nutation.


1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.


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