Kinematic Calibration Of Manipulators Research Articles

RGB-D 카메라를 이용한 로봇 매니퓰레이터 기구학 캘리브레이션

This paper proposed the robot manipulator kinematic calibration method based on a distance error model using an easy-touse RGB-D(Depth) camera. The RGB-D camera attached to the robot end effector measures the checkerboard’s corner 3-D position in two different positions. The homogeneous transformation matrix having rotation matrix and translation vector between two different RGB-D camera positions is calculated from the acquired position data from the RGB-D camera. The distance error is measured by comparing the distance moved by the RGB-D camera from the derived homogeneous transformation matrix with the distance moved by the robot manipulator. Simulation and experiments have been conducted to verify the proposed robot manipulator kinematic calibration method with a 6-DOF robot manipulator.

Stewart parallel manipulator kinematic calibration based on the normalized identification Jacobian choosing measurement configurations

Stewart parallel manipulator kinematic calibration based on the normalized identification Jacobian choosing measurement configurations

Configuration Optimization for Manipulator Kinematic Calibration Based on Comprehensive Quality Index

Kinematic calibration performance is heavily dependent on two factors-the ability of calibration configurations mapping kinematic parameter errors, and the un-modeled errors including joint clearance, thermal expansion, and measurement noise. Therefore, this paper deals with the calibration configuration optimization to reduce the impact of the two factors on calibration performance. We pay particular attention to establish an index for evaluating calibration configuration's quality. Different from other works, the proposed comprehensive quality index can simultaneously reflect configurations' observability and globality. Furthermore, the numerical methods are used to analyze the relationships between the comprehensive quality index and configuration number, and the relationships between calibration performance and configuration number. Based on the above relationships, we provide a feasible solution for determining the calibration configuration number of a specific manipulator. Based on the above work, configuration optimization model is established and solved by particle swarm optimization. The simulation of an eight degree-of-freedom manipulator illustrates the advantages of the proposed method. In 100 calibration simulations, optimized configurations perform better than random configurations, with the position accuracy increased by 43.86% and the attitude accuracy increased by 14.29%.

A svd-least-square algorithm for manipulator kinematic calibration based on the product of exponentials formula

In recent years, a great deal of research is conducted to improve the accuracy of manipulator kinematic calibration of which the product of exponential formula (PoE) is used to represent the manipulator kinematics, whose purpose is to solve the singularity problem of the Denavit-Hartenberg (D-H) parameters. However, the noise sensibility is still an open problem since a matrix inverse calculation of Jacobian matrix is inevitable during the process of solving the kinematic-linearized-equations to obtain the calibrated parameters. This problem may causes non-convergence, or low-accurate solution of calibration algorithm if the environmental noises and the error of endeffector’s actual frame measurement techniques are considerable. This paper presents a kinematic calibration method using singular value decomposition least square algorithm based on the product of exponentials formula (SVD-PoE-least-squares algorithm) to improve the accuracy of calibrated parameters. The proposed algorithm is evaluated in simulation level using a 6-DOF puma 560-type manipulator. The obtained results have shown that SVD-PoE-least-square algorithm is insignificantly affected by environmental noises, and, the proposed method can complete the robot calibration with respect to the work frame directly.

Three-dimensional calibration of micromanipulators using stereo vision

Calibration is of great significance in the development of automatic micromanipulation systems. This paper presents a novel vision based procedure for three-dimensional (3D) calibration of micromanipulators. Two major issues in the proposed calibration approach - vision system calibration and manipulator kinematic calibration - are discussed in detail in this paper. Verification and evaluation experiments are conducted using a 3D micromanipulator in a microrobotic fiber characterization platform. Experimental results demonstrate that the proposed calibration approach is able to achieve prediction errors below 5 μm. The proposed approach also demonstrates the feasibility of calibrating the decoupled motions, by reducing the undesired movement from 28 μm to 8 μm (for 4,800 μm desired movement).

Forward Calibration of Closed-Loop Jointed Manipulators

A method for performing forward kinematic calibration of manipulators with one or more closed-loop actuated joints is presented. The technique is an extension of algorithms de signed for open-loop jointed manipulators and is equivalent to minimizing a constrained objective function. The con straints arise from the closed-loop mechanisms in the manip ulator. The objective function is taken as the integral of end effector position and orientation error and is optimized using the method of Lagrange multipliers.

Comment on “generalized joint model for robot manipulator kinematic calibration and compensation,” by M. R. Driels and U. S. Pathre

Comment on “generalized joint model for robot manipulator kinematic calibration and compensation,” by M. R. Driels and U. S. Pathre

Completing the forward kinematic calibration of open loop manipulators when single point position sensors are used

AbstractSingle point sensors can measure the position of one point fixed to a manipulator's end effector. When single point sensors have been used for calibration, it has not been possible to calibrate the orientation of the tool. Furthermore, it can be difficult to calibrate the sensor system. Results in the literature seldom provide a complete kinematic calibration of the manipulator. Presented here is a technique that enables single point sensors to gather sufficient information to complete kinematic calibration. In addition, the method can reduce the burden of calibrating the sensor system.

Generalized joint model for robot manipulator kinematic calibration and compensation

AbstractA generalized model that goes beyond the usual assumption of “ideal” joint behavior is proposed. The “real” joint has five ancillary degrees of freedom besides the dominant motion. The resulting manipulator transformation with its greater degree of sophistication is expected to help in calibration and compensation of the various kinematic contributions to robot inaccuracy. The procedure to compute this generalized manipulator transformation is presented. The generalized model also results in manipulator differential relationships and these are discussed.