Study On Signal Acquisition And Processing System Of A Micro Six-axis Accelerometer

The six-axis accelerometer can sense the six-axis acceleration (including three-axis linear acceleration and three-axis angular acceleration) of the motion of a measured object. Through integrating the acquired six-axis acceleration over time, the velocity, location, and posture of the measured object can be acquired. The potential application prospects of six-axis accelerometers will be found in automation control, transportations monitoring, earthquake monitoring, robot control, and navigation technology. Miniaturization is the development trend of six-axis accelerometers. The micro six-axis accelerometer based on multi single-axis accelerometers has the advantages of low cost and small size. In order to realize the practical application of the micro six-axis accelerometer, signal acquisition and processing systems with low cost, miniaturization, and high accuracy must be studied and developed. Up to now, the signal acquisition and processing system for the micro six-axis accelerometers has no mature scheme.This thesis has proposed a principle and structure of the signal acquisition and processing system that corresponds with the six single-axis accelerometers-based micro six-axis accelerometer developed by our laboratory. According to the principle and structure, the hardware circuit and software system of the signal acquisition and processing system are developed. On this basis, the experiment test system is established, through which the characteristics of the signal acquisition and processing system are tested and analyzed.The major research work and results in this thesis include:1. The principle, configuration, and sensing characteristics of the micro six-axis accelerometer are analyzed. On this basis, the principle and structure of the signal acquisition and processing system are proposed. The system consists of a core board and an extended interface board. The core board is responsible for the signal processing of the system and coordinates the functional units in the extended interface board. The extended interface board acquires the signals and then transmits the processed signals to the external devices under the control of the core board. Through the design proposal, the modularity and miniaturization of the signal acquisition and processing system are realized.2. The hardware circuit of the signal acquisition and processing system is designed and developed, including a core board and an extended interface board. The core board uses digital signal processor (DSP) and peripheral circuit to realize the signal processing of the micro six-axis accelerometer output, and control the chips on the extended interface board. The extended interface board uses A/D converting circuit, D/A converting circuit and universal serial bus (USB) interface to realize the functions of signal acquisition, analog signal output, and digital signal output.3. The software system for the signal acquisition and processing system is designed and developed. The software system is composed of signal acquisition module, signal processing module, and output interface module to realize the signal acquisition, signal processing, and data output combined with the hardware circuit.4. The experimental test system of the signal acquisition and processing system is established. And the experimental results show that the developed signal acquisition and processing system can realize real-time acquisition, processing, and outputing of the output signals of the micro six-axis accelerometer. For the signal acquisition and processing system, the error of A/D acquisition is±0.01 V, the error of the calculated linear accelerations is±0.05 m/s~2, and the error of the calculated angular accelerations is±1.5 rad/s~2.The research work in this thesis provides a principal scheme to realize the signal acquisition and processing system for micro six-axis accelerometers and lay a foundation for the practical application of micro six-axis accelerometers.