A control-parameter data collecting and processing system of grain drying in a deep fixed-bed

Accurate data acquisition and processing is important to analyze the experimental results and research the theories of grain drying. Experiments of grain drying in a deep fixed-bed usually have characteristics of long period, difficult dynamic signal acquisition, large amount of experimental data and cockamamie data processing, etc. Aiming at the disadvantages of tiresome procedure, low efficiency and big error which exist in the traditional manual record and data processing mode for test process, an automatic multiparameters collecting and processing system for the experiments of grain drying in a deep fixed-bed is developed. The system mainly consists of two parts: testing software of master computer, hardware and software of slave computer. A microcontroller is used as the central control unit of the slave computer. Both design of the hardware interface circuit and the data acquisition program have been accomplished. Analog signals of sensors are collected and sent to the master computer by serial communication mode. Software of data processing and analysis used for the master computer operation is developed by using software development tool Excel and VBA on the base of software engineering method, theories of grain drying and experimental design method. The software can automatically analyze and process the regulate control parameters of drying air temperature, drying air velocity, humidity, paddy thickness and intermittent drying time, which were all collected and sent by the slave computer system,and then it can give regression equations and graphics of influence laws of each regulate control parameter on paddy rice driedquality( additional crack percentage, drying homogeneous degree and drying time, etc.) automatically by applying the function modules of regression analysis, principal component analysis (PCA) and parameterization drawing, etc. A series of paddy drying experiments including single-factor experiments and quadratic orthogonal rotary combination experiments in a deep fixed-bed were conducted with the developed system. The results showed that the system works stably and reliably by compared with the traditional manual record, while labor intensity and interference on data processing of manual operation cloud be decreased during the drying experimental study, and data analysis precision and reliability of experiments also be improved.