Applied Mechanics and Materials Vols. 241-244

Abstract: In order to lower the measurement system errors in aluminum electrolysis reduction, and find out the abnormity of process parameters, this paper considered the process parameters in the production process, used mean-range control chart in statistical process control to analyse aluminium level data during aluminium electrolysis reduction, designed and implemented the statistical process control system for aluminum electrolysis reduction data, presented process improvement method for aluminium level data. Results for the 300KA aluminium electrolysis cell show the statistical process control system can ensure the stability of aluminium electrolysis pot process parameters, find out specific reasons of abnormal data, keep the material balance and energy balance, improve current efficiency, and reduce the energy consumption.

Abstract: According to characteristics of the fruit and vegetable picking operations, an articulated picking robot with four degree-of-freedom is developed. And in order to perform an expected motion of picking work, the kinematic and dynamic models have to be constructed firstly. Kinematics is established based on Denavit-Hartenberg notation. Then, the explicit expressions of dynamic models are presented through Lagrange equation. Finally, trajectory planning from one point to another point is carried out with cycloidal motion, and the angular displacement, velocity, acceleration and torque curves of each joint are analyzed. Simulation results show that the torque curves are quite smooth and with no abrupt changes, which indicates that the motions of each joint won’t result vibrations and can ensure stability of the robot system.

Abstract: In order to improve the performance of dual-loop speed control system and overcome the defect of the traditional PID controller parameter tuning, a hybrid algorithm(BF-PSO) of Bacterial Foraging Optimization (BFO) algorithm and Particle Swarm Optimization(PSO) algorithm is proposed in this paper, and applied to PID parameter tuning of the double-loop speed control system. This algorithm combines the fast convergence characteristics of PSO and strong global search ability of BFO. Compared with the simulation results of the PSO and BFO, BF-PSO has better speed tracking performance, and higher convergence speed and robustness.

Abstract: A visual servo simulation model for puma560 robot based on homography matrix decomposition was designed. Utilizing the Robotics Toolbox and Machine Vision Toolbox, the simulation model of the visual servo system was built using the sub-systems in Matlab Simulink. Finally, the experimental results show the visual servo system can enable the robot to reach the desired position quickly and accurately.

Abstract: Supercapacitor is widely used in high power energy storage device, and its charge and discharge properties decide the energy storage devices of important performance indicators. In this paper, in order to research the charging performance of supercapacitors, a constant current test system which is based on microcontroller was designed. The system use a program-controlled constant current source which focuses on high-power MOSFET in accordance with the current data gotten from the sampling circuit, adjust the output current by PID algorithm, and thereby enhance the controlling precision of the output of the constant current. Under the combined control between upper machine and lower machine, the test system can map out potential function curve following time-varying, so that the supercapacitor’s charge process implement visualization. The result which tests the supercapacitor shows that the circuit has a simple structure and the current is very stable, which can be applied to all kinds of energy storage device which requires high current for charge and property test.

Abstract: Accurately measuring capacitive current for the automatic tuning arc-suppression coil is the premise and basis of realizing its compensating and arc-extinguishing functions. Several principles measuring capacitive current applied widely are theoretically analyzed and compared. The resonance method to measure the capacitive current has high precision, but has complex tuning. The displacement voltage method has simple tuning, but has poor accuracy of measuring capacitive current. The measurement accuracy of the impedance triangle method and the E0 measurement method lies between the resonance method and displacement voltage method. And its tuning is also relatively simple, but its measurement and control system is more complex. At last, to choose appropriate capacitive current measurement method according to the arc-suppression coil tuning principle and the distribution network operation is pointed out.

Abstract: In this paper, we proposed a novel street lighting system called Distributed Street Lighting Control System with IntelliSense (DSLCSI), and on this basis, five-end architecture, an ItelliSense extension mechanism and a cable theft detection method are described in turn. DSLCSI is presented to overcome the complex configuration, poor scalability and low reliability of cable theft detection methods in existing street lighting system. The results of field application show that DSLCSI provides convenient system scalability and maintainability, and improves the reliability of cable theft detection.

Abstract: DC-link voltage balancing method is the key technique of cascaded static synchronous compensator (STATCOM) while safety and reliability is required previously. However, independent control scheme is necessary for each H-bridge in consideration of the voltage balancing strategy, which is different from the assumption of carrier phase shift modulation algorithm. The influence of voltage balancing strategy on cascaded STATCOM was analyzed in detail and several feasible solutions were proposed, experiment results were shown to validate the presented analysis in the end.

Abstract: This paper is concerned with the identification problem of two degree of freedom robot arm’s joints’ time-varying stiffness. The dynamic equation of two degrees of freedom robot arm can be obtained by using analytical mechanics method. Then by choosing limited memory least square method, time-varying stiffness can be identified. Finally, the calculative stiffness is compared to the “real” stiffness which is simulated in ADAMS. The whole process shows that the robot arm’s dynamic model and the method of identification are both effective.

Abstract: In this paper, a robot handling system was developed with the functions of visual positioning and position adjustment by using the MOTOMAN-SV3X robot. System components, workflow, robot pose and the method of solving the problem of pick-up position deviation were detailed. An automated and flexible application program was provided for robot handling technology, and the problem that there was pick-up position deviation in the process of transporting workpiece can be effectively resolved, thereby handling precision and efficiency can be improved.