Research On Key Technologies About Motion Control System Of 800-Speed Automatic Biochemical Analyzer

Automatic biochemical analyzer is an indispensable clinical laboratory instruments, through the quantitative analysis of biochemical indicators of body fluid to determine the body’s physical health. Such equipment can completely replace manual operation, but also has high speed, high test precision, high reliability.On the basis of the full study domestic and foreign automatic biochemical analyzer,this paper introduces the analyzer’s basic principles and analyzes its overall design. Then,the sample handling system as the main object of study, the key technologies of automatic biochemical analyzer motion control system was researched. Sample handling system is a complex mechatronic system, this paper analyzes the system structure, reveals the hardware requirements of sample handling system, which is according to the motion index of the sample handling system, and develops the overall program.Fristly, hardware system uses the distributed control architecture. Common hardware platform based on ARM and FPGA works as the core, and accepts the sensor information collected by the Liquid Level Detection(LLD) module or the Clogging needle detection module. In this Design, the LLD module based on PLL principle can be self-calibration. Secondly, control strategy is divided into two layers, the servo driver layer, the PID control algorithm was used in the closed-loop system consists of a stepper motor and encoder; in trajectory planning layer, adaptive controllable speed S-type plan is researched, and trajectory planning of sampling manipulator is completed in the joint space.Finally, all control strategies is realized on the common hardware platform, and achieve the purpose of precision closed-loop control on sampling robotics and micro-pump.Experimental datas show that the reaction time for the liquid level detection system is 1.6ms, the horizontal position repeatability of sampling manipulator is 0.21 mm, the repetitive positioning accuracy of the vertical direction is 0.15 mm, the minimum sample volume is 2μL, and the maximum amount of sample is 35μL. All index meet the actual needs of automatic biochemical analyzer, along with better reliability and stability.