Wen-Bo Li

Bio: Wen-Bo Li is an academic researcher from Shenzhen University. The author has contributed to research in topics: Robot calibration & Robot kinematics. The author has an hindex of 3, co-authored 8 publications receiving 41 citations.

Analytical inverse kinematic solution using the D-H method for a 6-DOF robot

Abstract: This paper proposes an analytical approach to solve inverse kinematics of a 6-DOF robot. The robot discussed here is designed with 6R configuration. The D-H model of the six-axis robot is built. The forward analytical solution is deduced using the D-H method. Then, analysis of inverse kinematics for the robot is presented. And finally, the validity of the inverse kinematic equations is verified. Forward kinematic equations and inverse kinematic equations are suitable for all kinds of robots with configuration similar to those of the robot in this paper.

A calibration algorithm of the structured light vision for the arc welding robot

Abstract: Structured light vision is now widely used in weld seam detection for arc welding robot due to its simple structure, high precision, low cost, and real-time characteristic. By taking use of optical triangulation measurement principle, the position of welding seam is able to be measured. Calibration is one of the crucial step before structured light vision can be actually used in the welding system. In this paper, a calibration algorithm of the camera and laser is deduced mathematically, which involves the calibration algorithm of intrinsic parameters, extrinsic parameters of the camera and the calibration algorithm of laser plane equation which respect to the camera coordinate system. A structured light vision system is implemented, consists of a CCD camera a linear structure laser and a calibration chessboard, to verify the validity and practicality of the algorithm. By measured the standard object, the experiment results are carried out and the measurement error are analyzed. The experiment results show that the calibration algorithm is able to meet the demands of accuracy for arc welding robot.

An algorithm of hand-eye calibration for arc welding robot

Abstract: Vision-based seam tracking sensor is now widely used in arc welding robot due to its non-contact, high- precision, real-time characteristics. It is able to detect the weld seam position, and transform the position from camera coordinates to robot base coordinates. To realize such transformation, the hand-eye matrix which is the transformation relation between the camera and end-effector (EE) of robot is needed. In this paper, the mathematical model of the hand-eye problem is given, and a hand-eye calibration algorithm is proposed. The simulation experiments are given to analyze the calibration errors caused by the measuring noise. The experiment results show that the proposed algorithm meets the demands of accuracy for the arc welding robot.

Development of a 4-DOF SCARA robot with 3R1P for pick-and-place tasks

Abstract: The planar robot is very suitable for moving workpieces which are in high demand in industrial automation. This paper develops a 4 degree of freedom (4-DOF) selective compliance assembly robot arm (SCARA) robot with three rotary joints and one prismatic joint (3R1P) to realize pick-and-place tasks of the circular and rectangular workpieces. The structure of the robot is firstly presented. The kinematic model is then built, and the kinematic analysis is performed based on MATLAB. The trajectory planning is further implemented. A control interface is also designed via Visual C++ to control the robot for achieving pick-and-place tasks. The validity of the developed robot is finally verified through experimental results.

A meta-heuristic proposal for inverse kinematics solution of 7-DOF serial robotic manipulator: quantum behaved particle swarm algorithm

Abstract: In this study, a quantum behaved particle swarm algorithm has used for inverse kinematic solution of a 7-degree-of-freedom serial manipulator and the results have been compared with other swarm techniques such as firefly algorithm (FA), particle swarm optimization (PSO) and artificial bee colony (ABC). Firstly, the DH parameters of the robot manipulator are created and transformation matrices are revealed. Afterward, the position equations are derived from these matrices. The position of the end effector of the robotic manipulator in the work space is estimated using Quantum PSO and other swarm algorithms. For this reason, a fitness function which name is Euclidian has been determined. This function calculates the difference between the actual position and the estimated position of the manipulator end effector. In this study, the algorithms have tested with two different scenarios. In the first scenario, values for a single position were obtained while values for a hundred different positions were obtained in the second scenario. In fact, the second scenario confirms the quality of the QPSO in the inverse kinematic solution by verifying the first scenario. According to the results obtained; Quantum behaved PSO has yielded results that are much more efficient than standard PSO, ABC and FA. The advantages of the improved algorithm are the short computation time, fewer iterations and the number of particles.

Teaching and learning robotic arm model

Abstract: In this paper, the design and development of a robotic arm controller that enables use of a robotic arms as practical laboratory model for teaching and learning of robot arm algorithms is presented. The proposed system consists of OWI robotic arm with 5-Degrees Of Freedom (DOF) with DC motors for each joint movement, Arduino based control unit for control of arm motion and a MATLAB based Graphical User Interface (GUI) with kinematics algorithm at the backend providing user friendly environment for controlling the end-effector of robot arm remotely. The robotic arm is equipped with accelerometers to provide feedback to the microcontroller. The kinematics algorithm is implemented in MATLAB. The MATLAB based GUI, Arduino controller and accelerometers together with the robotic arm provide the practical laboratory model of teaching learning robotic arm platform. This robot arm also provides stand alone operation for pick and place application with the use of Arduino controller and accelerometers.

Improving the Efficiency of Automated Precision Robotics-Enabled Positioning and Welding

Abstract: This paper presents the concepts and fragments of algorithmizing the improvement in the quality of welding thin-walled metal products in a robotic manufacturing environment. The proposed solutions will significantly reduce the reject rates applicably to pipelines of complex configuration made for aerospace industries-at the cost of a slightly slower process. The paper proposes an information module for precise configuration of weld workpiece positioning, which minimizes misalignments caused by preparation defects, in particular stamping and pruning defects. The module can run automatically or semiautomatically to support the operator's decision-making. The module can be integrated in the CAM system of a robotic facility thanks to using compatible data formats; as such, it does not require significant extra processing on the part of robot controllers.