DSP在加速度计测试中的应用

Application of DSP in Accelerometer Measure System

克服等精度测频法在提高频率测量精度时必需提高有源晶振频率的弊端,设计了一种基于DSP技术的频率测量仪.采用DSP锁相环技术(PLL),将外部输入时钟频率提高5倍,作为时标信号;通过DSP片上高速定时器完成采样速率设定功能;利用外部CPLD构成两个32位高速计数器和计数器开闭控制电路.克服了等精度测量法测量频率的难点,有效地解决了加速度计测量中频率测量的关键问题.使频率测量精度达到10-8,经实际使用,效果良好.

A frequency measure system is designed based on DSP technology to overcome the diasdvantage that the crystal＇s frequency must be increased when equal precision frequency measure is used to improve the accuracy of frequency measure. DSPPLL technology is applied to increase the exerior input clock frequency by 5 times. The sampling rate is set up by DSP on-chip high speed counter,and two 32bit high speed counters and the counter-controlled electric circuit are constituted by the external CPLD. The technolgy overcomes the difficulty in equal precision frequency measure, and solves effectively the key problem of frequency measure in accelerometer measure, with frequency measure precision up to 10-8. Good results were obtained in practice.