Research Of Small Resistance Measurement Based On Embedded Simulation Technology

As the amplitude of weak signal is too small, and there exists the interference ofnoise signal, it may cause weak signal itself can’t be recognized easily, Therefore, it’svery difficult to detect weak signal accurately. However, highly accurate detectiontechnology of weak signal is used widely, such as: research, engineering andmanufacturing, aerospace, military, medical and other fields where various weak signalsare exist. And the weak voltage signals have more interference factors, and are moredifficult for detection. Therefore, the research on how to improve the measuringaccuracy of the weak signal is of great significance.Micro resistance measurement module and programmed decoding module aredesigned by two pieces of microcontroller AT89S52which are used for hardwaredesign. The constant current source control system, the sampled signal data processingsystem, display module, electronic multi-channel switch module, decoding systems aredesigned around the two modules. Constant current source control system needed tomeet the various requirements of current measuring, such as: current size is adjustable(0~1A) and the current direction is controllable. Electronic multiple switch modulesprogrammed with coding system will meet the needs of the36channel changedetection which required in automatic measurement. Micro resistance measurementmethod is analyzed in the measurement module of micro resistance; the way how toreduce measurement error and four-wire resistance measurement method are discussedin this paper; the data collection and processing of micro resistance is analyzed,including power control and data collection.36multi-channel electronic switch and itsdecoding system and communication serial port expansion are mainly designed in thedecoding module. Decoding module can be communicated with micro resistancemeasuring module.Microsoft Visual C++is mainly used for the development of automaticallymeasuring PC software, and the software includes code design of measuring location,serial communication design and database design.On the research method, variety of error sources are analyzed and the interferenceconditions are tested to compensate or eliminate these errors, analyzing and optimizing the design method which is proposed in this paper. The paper also analyzes four-wiremeasurement circuit with embedded simulation technology, and improves approach tooptimize the measurement in the simulation options. By choosing a reasonable methodas the main form of weak resistance measurement, wire error is removed. Embeddedsimulation technology is used for system identification of four-wire measurementcircuit system, and genetic algorithm is used for simulation measuring and parameteroptimization of the entire measurement system. Finally, this method is proved to havevalidity and high precision by parameter optimization of genetic algorithm andsimulation results.