Applied Mechanics and Materials Vols. 190-191

Abstract: The UGV (Unmanned Ground Vehicle) FLGPR (Forward-Looking Ground Penetrating Radar) imaging model spatially variable characteristics lead to the relatively low image SCR (Signal-Clutter Ratio). In order to improve the image quality and improve the SCR, the coherence properties of the target in image sequences is used for image enhancement. That is, images from the same region at different time sequence are enhanced two times. First of all, CFAR (Constant False Alarm Rate) is a preliminary step to enhance the image sequence, and then PCA-CFAR-MNF enhancement algorithm is proposed: according to the iterative nature of the MNF (Maximum Noise Fraction), PCA (Principal Component Analysis) method is first used to transform selecting and then CFAR detection is used to estimate the image background in the iteration,. The measured data show that the proposed method not only keeping the target characteristics, but also have remarkable image enhancement effect, and have greatly improved SCR.

Abstract: The gap and the malposition of the contact of automotive relay would heavily influence its life. If the gap and the malposition of all relays can be fully inspected and the inspection operation can be incorporated into the existing automated manufacturing and testing equipment, the quality will thus be significantly promoted. To reach this goal, a visual inspection system based on the platform of LabVIEW has been developed in this paper. The visual inspection system is capable of performing the inspection of the gap and the malposition of electrical contact in 1.6 seconds for one relay, and the whole automation system can manufacture one relay for every 2 seconds.

Abstract: The article develops an auto-charging system for mobile robots, and programs a new docking processing to enhance successful rate. The system contains a docking station and a mobile robot. The docking station contains a docking structure, a limit switch, a charger, two power detection modules and two wireless RF modules. The mobile robot contains a power detection module (voltage and current), an auto-switch, a wireless RF module, a charging connection structure and a laser range finder. The docking structure is designed with one active degree of freedom and two passive degrees of freedom. The power detection module is controlled by HOLTEK microchip. We calculate the power values using the redundant management method and statistical signal prediction method, and develop an auto-recharging processing using multiple sensors and laser range finder for mobile robots. The processing can enhances the successful rate to guide the mobile robot moving to the docking station. In the experimental results, the power of the mobile robot is under the threshold value. The mobile robot transmits the charging command to the docking station via wireless RF interface, and searches the landmark of the docking station using laser range finder (SICK). The laser range finder guides the mobile robot approach to the docking station. The mobile robot touches the docking station to trig the power detection device. The docking station supplies the power to the mobile robot by charger, and detects the current and voltage values of the charging processing. The charging current of the docking station is under the threshold value. The docking station turns off the charging current, and trigs the mobile robot leaving the docking station via wireless RF interface.

Abstract: Retinal vascular bypass surgery (RVBS) is a kind of complicated operation, with high precision and dexterous manipulation limited to small workspace. It is necessary to design a robot-assisted manipulator for performing such a task. The process of RVBS is described according to clinic operation at first. The motion of surgeon and workspace of surgical instruments are analyzed; correspondingly, motions of robot-assisted manipulator are obtained. Then, mechanism of manipulator including remote center of motion (RCM) is proposed through considering constraints induced by pierce points of sclera. Finally, inverse kinematics of the proposed robot-assisted manipulator is done to realize retinal surface motion. The analysis results show the end-effectors of robot-assisted manipulator can reach arbitrary position on the retinal surface.

Abstract: Error compensating PID regulation algorithm was applied to design the shock absorber electro-hydraulic servo-testing system, which conforms to national standard QC/T 545-1999,. According to adopt the MTS407 controller, implement indicator diagram testing, speed diagram testing, friction diagram testing, temperature wearing diagram testing, wearing life testing, single and double actuator testing and whole frequency testing are implemented. After the experiment conducted by using shock absorber CA1049, the result shows that the testing system can collect mass data, and is high precision.

Abstract: The humanoid robot is a combination of biped, intelligent and mimetic robot to serve human beings in non-production sectors. Since it is a very complicate automatic walking and working machinery, and it works interactively with people in daily life, its correctness and reliability in terms of its functions and performances need to be checked intensively after final assemble and before it is shipped. A novel developed computer integrated testing system (CITS) to inspect every ex-work robot before shipping with the appearance, motion, walking, sensing and recognition, intelligence as well as possessed service expert knowledge is developed in this paper. The use of this fully automated CITS will simplify the human intervenient inspection and testing of the humanoid robot, shorten the testing time and cost, and avoid human errors while in manufacturing, software loading and ex-work inspection.

Abstract: The present paper discusses temperature distribution of Thermoelectric Generator (TEG) using automotive waste heat , an index to evaluate the temperature uniformity of hot end box surface of TEG is proposed. Three-dimensional heat transfer model is established to simulate the temperature distribution on hot end box surface of TEG with computational fluid dynamic program FLUENT. The simulation result indicates that under the same topology of thermoelectric modules , the internal structure inside the hot end box could effectively improve the heat transfer between waste gas and hot end box, raising the hot end box surface average temperature by 7.2 percent from 534.2K of to 572.6K ; raising the temperature uniformity coefficient by 4.8 percent from 0.83 to 0.87, the result shows that the waste gas could be utilized more efficiently and generate more output.

Abstract: The article develops multi-pattern formation exchange using A* searching algorithm, and programs the shortest motion paths for mobile robots. The system contains an image recognition system, a motion platform, some wireless RF modules and five mobile robots. We use Otsu algorithm to recognize the variety 2D bar code to classify variety pattern, and control five mobile robots to execute formation exchange, and present the movement scenario on the motion platform. We have been developed some pattern formations according to game applications, such as hook pattern formation, T pattern formation, L pattern formation, rectangle pattern formation, sward pattern formation and so on, and develop the user interface of the multi-robot system to program motion paths for variety pattern formation exchange on the supervised computer. The supervised computer programs pattern formation exchange according to the image recognition results, and controls mobile robots moving on the motion platform via wireless RF interface. In the experimental results, mobile robots can receive the pattern formation command from the supervised computer, and change the original pattern formation to the assigned pattern formation on the motion platform, and avoid other mobile robots on real-time.

Abstract: In this paper, a novel approach of linear octree is employed to represent discrete tools and build their swept volumes along machining trajectories. Firstly, a data structure of linear octree is defined as the base of geometrical transformations. The linear octree can be extended into leaf nodes in the deepest level for simplifying homogeneous transformations, and all leaf nodes in the deepest level can also be concentrated into a linear octree for saving storage capacity inversely. Secondly, tool trajectories are interpolated as short lines, and swept volumes between neighbor interpolation points are defined as the Minkowski sum of their cell sets at both locations. Thirdly, equations of the rotation matrix for local coordinate system, roll, pitch and yaw angles of tool orientations are established to define the global rotation motions. Finally, a case of discrete sphere tool and its swept volume modeling are studied to validate the proposed approach.

Abstract: In this paper, nonsingular terminal sliding mode control strategies are originally presented for mobile robot in the presence of uncertainties and disturbances. The support vector machines is used to approximate an unknown controlled system from the strategic manipulation of the model errors. Based on the Lyapunov stability theory, it is shown that the proposed controller can prove the stability of the closed-loop system and guarantee tracking performance of robotic system. Finally, simulation results validate the superior control performance of the proposed control method.