The Design Of Multi-channel Magnetoelastic Sensor Detection Instrument Based On FPGA

Magnetoelastic sensing technology has been developed in last 10 years as a new sensor technology. It is a wireless, passive sensor based on magnetostrictive effect. The signal of the sensor is driven and excited by the electromagnetic fields. There is no physical connection between the sensor and the detection device. Magnetoelastic sensor has great prospects in vivo detection of life science, food quality and safety testing and environmental testing and other areas due to the wireless and passive feature of itself.With the development of embedded technology, SOPC technology based on FPGA has been developed rapidly. Compared with application-specific integrated circuit technology, the technology of SOPC embedded system based on FPGA has a flexible design approch.It can be cut and the system is scalable and upgradeable.It has programmable functions in hardware and software system.,and has become the main research direction in the design of embedded system field.This dissertation has a research on the detection instrument of the new strip magnetoelastic sensors, and designed a multi-channel magnetoelastic sensor detection instrument based on FPGA. The detection instrument focuses on the magnetoealstic biosensor and its applications in biochemical analysis. This article first discusses the significance of magnetoelastic sensor and the current study status about the magnetoelastic sensor at home and abroad. The requirements of 4-channel magnetoelastic sensor detection instrument are determined in the conceptual design phase, using a SOPC embedded system based on FPGA. Then the working principle and preparation of the magnetoelastic sensor and frequency sweep method for detection are introduced. In the part of system hardware design, Altera’s Cyclone FPGA is chosen to design a small system. The main circuit is also designed including bias circuit, peak detection circuit, AD converter circuit, USB circuit and power management circuit. Software design uses Quartus II to fulfill the completion of functional modules. In this part the completion of the 4-channel DDS module is presented. The soft processor Nios II is used to accomplish the SOPC embedded systems design. After the SOPC design, the software project is compiled and analyzed by timing analysis. The 4-channel magnetoelastic detection instrument introduced in this thesis is stable and reliable operation. The four measurement channels are independent and the process of the measurement for resonance frequency is parallel.User can set measurement parameters using the host computer interface designed by the LABVIEW software visual programming. It can display the measuring result in real-time and analyze the results quickly and accurately.