冲击加速度存储测试的变频采样策略分析

冲击加速度测试过程中信号存在低速、中速和高速变化的特点，采用固定采样频率完成整个测试过程的参数测试是不合理的，为了减少数据冗余、保证信号无失真恢复，在改变ADC采样频率的变频采样策略基础上，提出一种数字变频采样策略。使用两片存储器，以高速采样频率得到充足数据源并且以同样频率写入存储器1，根据信号变化特征改变存储器2的地址推进频率，对存储器1里的数据进行抽点存储，实现变频采样。经过Hopkinson杆上的冲击测试，变频测量系统具有抗冲击可靠性。仿真和测试表明，变频采样方法可以有效解决采样频率、数据容量之间的矛盾。

Analysis of frequency-change sampling strategy for impact acceleration storage measurement

The fixed sampling frequency is not reasonable for obtaining the signal parameters with variable changing speed during the measurement process of high-g acceleration. A digital frequency-change sampling method was put forward in this paper to reduce data redundancy and ensure signal without distortion as well based on the method of changing ADC Sampling-frequency. Two pieces of memory were used to fulfill this target. Sufficient data source got by high-speed sampling frequency was written to the first memory at the same frequency, and the address of the second memory was changed with frequency propulsion according to the characteristic of signal variation, then the data stored in the first memory was extracted thus the frequency-change sampling got realized. Frequency measurement system could bear high impact by Hopkinson bar. Simulation and experiment confirmed that the frequency-change sampling method proposed in the paper can effectively solve the contradiction between the sampling frequency and data capacity.