Based On The Automatic Analysis Instrument Controller Key Technologies, Embedded Water Quality Biological Toxicity

As the water being polluted more seriously, pollution abatement becomes more important.As the front-end detection devices for water pollution degree, toxicity analyzer for water quality detection is of tremendous significance.At present, most of water quality detection devices can just test several physical and chemical compositions,but can not test the total toxicity,and can not operate for long time.This paper adopts embedded system technology, information technology, communication technology and auto-control technology to design a total toxicity online analyzer for water quality detection. Photobacterium phosphoreum is adopted as biosensor to test total water toxicity; The analyzer can keep online operation for long time without human intervention; With Internet technology, the analyzer can achieve real-time data communications with remote control centre.This paper mainly researches into some key technologies which are used in the controller design of the total toxicity online analyzer for water quality detection. Furthermore, some relevant problems are solved to implement the controller system.The main jobs this paper has finished are as follows:1. In this paper, theoretical researches on EMC are carried out to give solutions to EMI problems. High speed circuit simulation software Hyperlynx designed by Mentor Company is used to make simulation to get the proper PCB layout parameters. And signal integration and EMC simulation is made after the PCB is finished. Furthermore, after theoretical researches into electromagnetic interference which is produced by the inductive devices, rejection measures are given to prevent interference caused by inductive devices.2. A closed-loop control strategy is designed for the hybrid stepping motor subdivided driving used in the testing device.A mathematical model is made for the two-phases hybrid stepping motor.Through studying stepping motor subdivided driving theories,a constant forque subdivided driving mathematical model is given for stepping motor.A fuzzy PI control method is used for the closed-loop control of the stepping motor.According to the fuzzy control theories,this paper makes a proper choice to the controlling rules and parameters for the fuzzy controller.So a stepping motor control system with good stability and high accuracy is finished.3. A proper cross compilation environment which is used for the OS transplantation and software developments is built up for the linux OS and ARM microprocessor.Then, the transplantation jobs for the bootloader vivi, embedded linux OS and Cramfs are finished.4. In this paper, hardware circuit architecture is built, and some relevant circuits are designed for the system; On the other hand, the software architecture is built, then some drivers for relevant hardwares are finished.5. Device debugging job with the mechanical equipments is finished.Finally relevant experiments are made to collect experimental data, and these experimental data are analyzed.Through analyzing the results of the equitment debugging and the experimental data, it proves that the performances of the analyzer controller reach the target which is expected when it is designed.