Mingyang Zhao

Development and Control of an Autonomously Obstacle-Navigation Inspection Robot for Extra-High Voltage Power Transmission Lines

This paper presents a mobile robot suspended on power transmission lines based on a novel movement mechanism with two manipulators and a body. After the inspection robot configuration is described, the kinematics of the inspection robot and the process of obstacle-navigation are analyzed in details. In order to achieve autonomously control the task-oriented integrated control architecture is adopted, and the architecture is a multi-agent system coordinate and organized by distribute blackboard. To achieve auto obstacle-navigation control, camera-in-hand system is adopted to realize power transmission line pose locating. With the power line locating algorithm, a dynamic position based look-and-move control structure is implemented to achieve line-grasping control. Experiments result shows that the robot can realize auto obstacle-navigation control and proves the valid of the control method

Dual Arms Running Control Method of Inspection Robot Based on Obliquitous Sensor

Inspection robot with dual wheels encounters upslope and down slope, when it runs on the overhead ground wires (OGWs) which displays catenary shape. The tilt of the body of inspection robot, which is caused by the angle variation of catenary in different position, will occur during running procedure, and disenable to check vertically the transmission lines by camera. An adjustment method, which can keep the body of inspection robot in horizontal pose, is presented by the obliquitous sensor changing the length of the manipulators in this paper. In order to implement the pose adjustment, the dynamic model is established by Lagrange method. Finally, the simulation and experiment results show that the adjustment method proposed is feasible

A Novel Running and Gripping Mechanism Design Based on Centroid Adjustment

One arm is hung on the overhead ground wires (OGWs), while the other arm is off the OGW when an inspection robot autonomously negotiates obstacles on OGWs. The inspection robots body tilts because the gravity torque is unbalanced, and it is difficult to negotiate obstacles autonomously. If the horizontal pose of the body is kept through the gripping mechanism, the gripping force will become bigger, and results in the damage of OGWs. A centroid adjustment method, which enables the centroid of the inspection robot to concentrate on the arm that is hung on OGWs, is proposed in this paper. That idea is applied in the design so that the running and gripping mechanisms ameliorate the strained condition of OGWs and reduce the extent of damage. A dynamic model is established in this paper, the simulation and experiments results prove that the method proposed is feasible

Research on the Kinematics and Dynamics of a 7-DOF Arm of Humanoid Robot

We have developed a highly flexible anthropomorphic 7-DOF robotic arm for a mobile humanoid robot. The kinematics of the arm such as workspace, singularity, the number and physical nature of self-motion are presented. The concepts and methodology of the inverse kinematics base on the self-motion of the arm are described. By this method the task and motion scheduling can simply be done. The formulations of dynamics and the dynamic effect due to the arms dead weight were analyzed.

Vision-Based Profile Generation Method of TWB for a New Automatic Laser Welding Line

An on-line vision inspection sensor system for the automation of laser welding processes in heavy industries is presented. A method of image process and features extraction for structured light image of laser welding has been developed. In order to set the range of interest, the Radon transform is applied to determine the x and y coordinate in image coordinate system. For image de-noising, the median filtering and bi-level thresholding are used. Furthermore, the middle line of the laser stripe is extracted. Finally, a five step search method is carried out to examine the bead width. A series of experiments show that the proposed method in this paper is effective, and its detection precision is much better than traditional methods.

A new surface inspection method of TWBS based on active laser-triangulation

An vision inspection sensor system for the automation of laser welding processes in heavy industries is presented. The system consists of PC based vision camera and stripe type laser diode. For image de-noising, a new surface inspection method of Tailor-welded blanks including in: median filtering, bi-level thresholding, opening and closing, mid-line of the laser stripe extraction, has been developed. After extracting the middle line of the laser stripe, the algorithms of calculating bead width, mismatch, weld slope, convexity, concavity, overthickness and undercut are proposed. Finally, A series of experiments show that the proposed method in this paper is effective.

Analysis and Design of a Novel Four-axis Plane Laser Welding System

This paper details a novel plane laser welding machine system which combines two large-scale steel blanks superposed together. Several methods are developed in order to solve the technical problems existing in plane laser welding system: It presents major-minor pressing sets which can control the deformation and eliminate the gap effectively; the design of the 4-axis machine which makes the X axis moving in small range and U axis moving in long range in the same direction can improve the precise and dynamic performance of the system. The experimental results show that this new system has potential for future industry application.

Development of laser stripe sensor for automatic seam tracking in robotic tailored blank welding

This paper describes the development of laser stripe sensor for automatic seam tracking system in robotic tailored blank welding. Laser stripe sensor which is used to obtain profile of weld seam plays an important part in seam tracking system. The sensor consists of a CMOS camera based on FPGA (field programmable gate arrays) and a stripe-type laser diode due to high speed requirement of tailored blank welding. Its measuring error and performance make a direct effect on the measuring accuracy and reliability of the seam tracking system. A mathematic model is established in order to analyse the influence on sensor error from the geometric parameters. And then the reasonable geometric parameters are yielded according to the simulation results. Additionally, careful considerations about laser diode have been under taken in this paper in order to obtain high quality raw images of laser stripe and the feature points for seam tracking of robot manipulation are calculated by feature extracting algorithm. Finally, some experiments are carried out for proving the efficiency of the laser stripe sensor.

Dual-beam structured light vision system for 3D coordinates measurement

Recognition and identification of weld environment and seam dimensional position by computer vision is a key technology for developing advanced autonomous welding robot. In this paper, based on the robot laser curve seam tracking background we present our dual-beam structured light system that generates richer information than obtained only from one structured light system. Then the orthogonal Zernike moments edge detection is adopted to localize the centre of the light stripe. The obtained centre precision is subpixel. At the same time, the calibration of the CCD camera and the dual beam structured light is given. In the end, the application of the proposed system is shown and experiments have been implemented and results show that the approach is feasible.

3D Simulation and Optimization Design of a Mobile Inspection Robot for Power Transmission Lines

It is necessary to inspect the power transmission lines periodically to maintain the power system efficiently and economically. There is obvious needed for a mobile robot replacing the labor to gain the desirable detection accuracy. By means of Pro/E and ANSYS, the method of 3D simulation and optimization design is applied to the inspection design. Tasks such as 3D mould, virtual assembly and FEA of important components, the design and analysis of particular parts of the mobile robot for power transmission lines inspection are executed. And virtual assembly of 3D model simulation proves the vertical layout method of the TBS-model satisfactory. The results gained by the software provide the methodology approval and efficient guidance for the inspection robot design