Applied Mechanics and Materials Vol. 415

Abstract: This research work is to develop a concept of movable virtual wall for miniature tasks operation of a master-slave manipulator arm with force reflection. The purposes are to improve accuracy of the operation and preventing over travelling beyond a desired boundary. The predicted distance of the end-effector can be calculated based on various end-effector and hand models. From the experiments, movable virtual wall shows adjusting some wall parameters, the over travelling through the forbidden boundary can be prevented and the possibility of further development to improve miniature tasks operation.

Abstract: This research work is to develop a controller that combines the position and indirect force control for the gemstone polishing process. The polished gemstones are attached to the end of drop-stick of the Chula Automatic Faceting Machine. The Chula Automatic Faceting Machine has 4-axis high precision motion control and the other 2-axis for spindle and crank motion. Many gemstones (number of gemstones will depends on the size of the gemstone) can be grinded and polished simultaneously with the result of uniform size and quality. In this research work, the controller is developed based on PID motion control. The reference position of the controller for the grinding process is obtained based on the compliance force control technique with known compliance model. This reference position will specified the pressing force for the grinding process indirectly. The controller developed in-house is used for testing with Cubic Zirconia gemstone which the hardness is 8.5 Mohs. The compliance model and appropriate parameters including the minimum and maximum boundary of polishing process can be obtained experimentally. Then all parameters obtained from the experiment can be used in the controller. The uniform size and quality of the multi-stone grinding and polishing process can be obtained with this controller.

Abstract: This paper put forward the idea of ice skater robot of passive wheeled type integrating the features of wheeled mobile robots and legged mobile robots. The motion principle of a kind of leg-wheeled robot was analyzed. On the basis of introduction of kinematics analysis, the paper gives the model of the robot kinematics, Meanwhile, the paper analyzes the motion condition of the robot.

Abstract: state grid electric power robotics laboratory has developed four generations of substation inspection robot, but large scope of substation outdoor and route of road surface condition is complex, the application of inspection robot produced strong constraints, the inspection robot under complex road conditions of obstacle ability put forward higher request. Through this study design of crawler obstacle-navigation platform enhances the obstacle negotiation ability, enable it to adapt to complex terrain conditions. Adopt six crawler structure, can cross the road the road opposite sides-to hold the substation, obstacles such as cable trench cover plate, and good stability, not easy to roll over, to the district of equipment to test the equipment, improve the ability of task. Key words: caterpillar; The obstacle-surmounting platform; Inspection; The robot

Abstract: This new high-rise building fire fighting robot is a multifunctional fire fighting cabin, which integrated detection of a fire, fire fighting, person search and rescue, etc. The robot is connected with helicopter by a cable and transported over high building by a helicopter. This paper presents the system structure, the position and attitude control strategy, and the control system including hardware and software, the control system is atwo-layer hardware structure, uses a PC as upper machine, a MCU as lower computer and a multi-task software system based on Visual C++ class structure. experiments demonstrate the reliability of the system and all performance indexes are satisfied with the designed requirement.

Abstract: Abstract. The technical requirements for sheet metal processing equipment to the complete set of on-line development. Through the analysis of the stamping processing complete sets of equipment on-line technical，provides based on SSCNET bus, PLC and touch screen and the whole on-line control scheme. On this basis, by establishing the line control system of the simulation system, verify that the design is feasible and can be used as on-line equipment operation of the real-time monitoring system. Intends to help of the manufacturing and site commissioning of the first line prototype.

Abstract: The space vector pulse width modulation (SVPWM), as a new kind of vector control technique, has the advantages of high voltage utilization, less distorted output, simple control method, etc. In this paper, the control technique is applied to three-phase photovoltaic (PV) grid-connected inverter system. It uses double loop control method combined with PI control technique. The simulation model of PV grid-connected inverter system is established in Matlab/Simulink. The simulation results show that the application of SVPWM technique effectively improves the dynamic performance of PV grid inverter system and the THD of grid-connected current is low.

Abstract: Chlorine dosing is a complicated system with time delay, time-varying, non-linear and coupling. In this paper, multivariable adaptive generalized predictive controller based on Smith predictor is proposed. Instead of the optimal predictor, the Smith predictor with adaptive identifying parameters can increase the robustness of the MIMO system. Simulation and application in water-works at Suzhou (China) shows that the algorithm can overcome time-varying, time delay and disturbance.

Abstract: For the characteristics of a new elevator twin elevator with multiple objectives and uncertainty of group control system ,this work proposed a method of twin elevator group optimization dispatching based on genetic algorithm (GA). On the basis of the analysis of structure characteristics of twin elevator, by means of putting twin elevator running rules into the multi-objective control strategy, the method constructed objective function for twin elevator group; the method utilized GA for the simulation of twin elevator group optimization dispatching, and compared it with the minimum waiting time algorithm. Research results show that the method is able to adapt to the running characteristics of twin elevator, and different traffic flow pattern. Compared with the ones of the minimum waiting time algorithm, average waiting time, long waiting time incidence and the numbers of elevator stops of genetic algorithm are all significantly reduced. Consequently, this method has a strong ability to adapt, and provides a theoretical basis for engineering application of twin elevator group control system.

Abstract: This paper presents environmental disturbance rejection in a 2-DOF inertial stabilization system by a combination of feedback and feedforward control. For feedback control, sliding mode control and the line of sight (LOS) stabilization are used for compensation of the nonlinearities, model uncertainties, friction and disturbances from outside environment. Although our mechanisms are carefully designed with statically balance, the center of the gravity will changed due to the configuration change during moving of the gimbal relative to an aerial vehicle. The disturbance torque from unbalance mass and gimbal geometry is unavoidable under the effect of the vibration of the aerial vehicle, which will lead to degrade the systems accuracy. Since the acceleration of the aerial carrier, due to the disturbance torque, can be measured, a feedforward disturbance rejection can be generated to compensate the disturbance torque. The experimental results confirm the validity of the control design procedure for the two-axis gimbaled stabilization system. The proposed controller is capable enough to overcome the disturbances and the impact of LOS disturbances on the tracking performance.