Papers by Author: Zhi Gang Niu

Abstract: This paper took the coal mine detection robot model TUT-CMDR for research. First of all, the three degrees freedom mechanical arm was installed on the robots body. By the same time, the theory of Euler angle and D-H method were established to analysis the posture and position of robot body and mechanical arm. After the integration, the centroid coordinates on the robot in any location was calculated. In the next place, mechanical arm angle change and the size of the load effect on both forward obstacle-surmounting and the barrier height were discussed. In the end, the three dimensional relationship diagrams of barrier height, barycenter, pitch angle, arms' swing angle and mechanical arms swing angle were drawn and the results of mechanical arm gesture planning were compared with the initial state. The theory will provide basis for robot obstacle-navigation control.

Abstract: This thesis regards TUT-CMDR type coal mine detection robots as the research object and put forward an application of optimized BP neural network based on Quantum Genetic Algorithm in PID Control of motor speed. Transfer function model of speed control system of TUT-CMDR motor was established. Firstly, initial weights and thresholds of BP neural network were optimized by Quantum Genetic Algorithm, and then BP neural network was designed to adjust the parameters of PID on line. Finally, the results show that the algorithm is feasible and superiority.

Abstract: To achieve an agile and accurate motor control performance on coal mine detection robots TUT-CMDR, Fuzzy-PID control and its model building method in the Simulink environment are explored. The transfer function model of the TUT-CMDR motor transmission system is established and M-files used to ascertain the gain of the PID control are compiled. The final value of the step block is configured to a variable and parameterized quantization factors and scaling factors are proposed to solve the problem of different basic universe for different final value. Some improvement is also made on the existing fuzzy control rules. Finally, the designed controller is proved to show a better control performance.

Abstract: In order to meet the need of identifying obstacles and navigating for the Coal Mine Detection Robot which is used to rescue life and detect environment from coal mine disaster, binocular stereo vision is researched and 3D model of objects around the robot is reconstructed by means of two cameras of visual system built in the robot. The two cameras are calibrated and two projection matrices of them are obtained. Then, two images of the same scene are obtained by the two cameras. The matching points of two-dimensional coordinate are got through Harris corner extraction and stereo matching. According to the principle of binocular vision, equations are obtained and solved by least square method, which can calculated the discrete points of 3D coordinate.

Abstract: PRS-XY hybrid NC machine tool is a 5-degree-of-freedom cutting machine, which is composed of a 3-degree-of-freedom parallel mechanism and a 2-degree-of-freedom series mechanism, and can be applied to machining and testing of machine parts with complex surface. In this paper, the kinematics principle of the machining tool is analyzed, and the kinematics model for calculating the location of the real control axis is deduced. Through the cutting experiment of a typical part, the kinematics principle of the PRS-XY hybrid machining tool is validated, and the results also indicated that the machining tool has the multi-coordinates machining ability and preferable machining precision.