| Solid-phase extraction is a technology mainly used in fast sample preparation,purification, chromatographic separation and other analysis. Automated Solid-phaseextraction workstation as a platform for solid-phase extraction technology, its mechanismoptimization and servo control system design is a prominent technical problems, became abottleneck of Solid-phase extraction technology promotion and application. This article carryout the solid-phase extraction workstation mechanism optimize and servo control systemdesigning, using genetic algorithms to optimize the reduction ratio of the mechanism,developed an open hardware control system and customized an embedded operating system,using the improved genetic algorithm to identify the parameter model and turn system controlparameters. This thesis was supported by Guangdong Province Strategic Emerging IndustriesProjects(2011A091101001), and the main research works are as follows:Firstly, this paper carried out the reduction ratio optimization studies of the solid-phaseextraction workstation’s drive mechanism, planning an S-curve speed for the stationmovement based on the analyze of station high speed motion control characteristics, and takethe shortest average running time of pick-and-place operations as optimization objectives atthe constraints of AC servo motor operating principles, using genetic algorithm to optimizedthe reduction ratio parameters of the mechanical drive mechanism, so as to give full play tothe performance of the AC servo motor, and minimize system cost.The paper developed an open control system based on PC add motion controller to meetthe real-time and dynamic characteristics requirements of the workstation control system, forthis hardware platform of motion control system, customized an EWF core Windowsembedded standard embedded systems, so that the whole system has a friendly interface,penetration preventing, operational reliability and economical characteristics.In this paper, in order to obtain an accurate plant’s mathematical model, derived theworkstation system dynamics model, and developed an EtherCAT real time communicationprotocol based experiment platform, using real-coded genetic algorithm to identify the modelparameters of solid-phase extraction workstation’s drive system driven by a PMSM, includingparameters difficult to measure in reality. Compared the result of simulation and experimentalmeasurement, position tracking error in a small range of-0.3~0.3, verified that theidentification result is feasible. A double-closed-loop control system was built on theidentified system model for workstation’s motor control system, and adaptive geneticalgorithm was used to minimize the integral time multiplied by absolute error to tuning PID control parameter. This method avoids the shortcomings of the user experience requirementsin Z-N traditional method, and is capable of tuning multiple parameters at the same time;greatly improve the efficiency of tuning.Finally, with the best servo control parameters carried out quick positioning experiment atthe system platform, position tracking results show that the system basically meet the fast,accurate and stable of control performance requirements.The result of this study can be used to solved common problems in the development ofsolid-phase extraction workstation, may contribute to the development of automatedsolid-phase extraction technology and improve the social productive forces... |
