Study On The Mechanical And Electrical Institutions Of Automatic Biochemical Analyzer

Full-automatic biochemical analyzer was presented, and its mechanical and electrical parts were designed including the mechanical design, hardware design and software design.Biochemical analyzer is an important clinical diagnostic equipment that is mainly used for analyzing and measuring all kind of fluid date including blood, urine and so on .By doing so, it can provide a scientific basis for doctors diagnosing and determining the condition of patients.Electro-mechanical sector of full-automatic biochemical analyzer mainly includes carrying system, ascending-descending system, imbibing-draining system and tray system as well as temperature control system and the keyboard-display. This design uses three MCU to control respectively.MCUⅠis responsible for motion control and it can make three stepper motors and a DC motor operate in a concerted way, in order to complete plus reagents and find space in motion. The design uses a locate mode including pulse counting and travel limit switch, etc. so as to ensure that all motor system fix position accurately. Carrying system, imbibing-draining system and tray system is controlled by the stepper motor .Its initial position is provided by the limit switch, while the other positioning is achieved by means of pulse counting. Lifting system is controlled by a DC motor. It has only two anchor points, and each point location is done by a limit switch.MCUⅡis responsible for the keyboard display program. The design provides a good platform for human-computer interaction by using the liquid crystal display and six stand-alone keys. Different interface has different treatment result on the same key. It can complete the choice of test items numbers, holding temperature, the setting of holding time value, the adjustment of the amount of the amount of reagents and informing SCM the location of various agents.MCUⅢis mainly responsible for controlling temperature. It is necessary to ensure a accurate temperature control, because of there is a high temperation require on various biochemical reactions. This design uses a Fuzzy PID contron algorithm. First of all, it adjust three parameters of the PID respectively according to deviation and the variance ratio of deviation. Then, it operates PID. Final, it adjusts the output cycle of PWM wave to complete the heating control according to operation result. This article is also carrying out MATLAB Simulation and the results show that the control is effective. The innovations of this design are as follows:1) Using three SCM completes the control of mechanical and electrical sector of full-automatic biochemical analyzer effcctively, thereby reducing the cost of full-automatic biochemical analyzer.2) Using a serial electrically erasable PROM 24C02 not only solves the problem of insufficient data storage space, but also links three SCM as a single mutual co-ordination entity, thereby ensures the reliable operation of a fully automatic biochemical analyzer.