Recursive Fixed Memory Extended Least Squares Method And Simulation Research The Research On Automobile Electronic Products Malfunction Auto-Detect System Based On CAN-bus

Recursive Fixed Memory Extended Least Squares method and Simulation ResearchThe least squares identification is a classic method of parameter estimation and the cornerstone of estimation theory. The least squares method is simple and practicable, with its recursive algorithm converging and reliable, so it is used very extensively. When identified model noise is complicated, the least squares method estimated results are not unbiased or consistently. The recursive algorithm appears saturated phenomenon of data with data increasing, which causes it losing amendatory ability slowly. In this part, fixed memory length has been combined with recursive extended least squares method, so the recursive fixed memory extended least squares method (RFMELS) is obtained. It resolved the problem that estimated results unbiased problem when noise is coloring and the data saturated phenomenon. At the same time, the validity and rapidity of system identification been increased. The simulation of RFMELS and RELS's recursive algorithm compared in MATLAB and the results indicated the superiority of RFMELS more than RELS.The research on Automobile Electronic Products Malfunction Auto-Detect System Based on CAN-busThe quality of automotive electronic product has been getting stricter and stricter with the development of automotive electronics technology, while the detection of circuit board has an important role for automotive electronic manufacture. The traditional way of detected hardware circuit board hasn't checked its function that is true or false. In this part, a malfunction auto-detect system is contrived based on CAN-bus for circuit board of automobile electronic product. Based on former experiences, we formulated a full application layer protocol and built network by CAN-bus, so the rapid transmission of detected information be ensured. All detected positions, which adopt AT89S52 MCU as the core control chip, have achieved the function of operating keyboard, malfunction printing, LCD display, system communication and so on. The system has the characteristic of strong versatility, high level of automation, fast detect ability, low the operator's skill asked for and so on.