基于希尔伯特-黄变换的转台角速率测量方法研究

Research on Measurement Method of Turntable Angle Velocity Based on Hilbert-Huang Transform

文中针对传统转台角速率测量采用定时测角、定角测时等时间段内求取平均值方法,无法获取转台随时间变化的瞬时角速率值的问题,对基于希尔伯特-黄变换原理的角速率测量方法开展研究。在分析莫尔信号自身特征的基础上,对莫尔信号进行希尔伯特-黄变换方法进行详细阐述;设计基于FPGA的角速率测量电路,详细说明了电路中经验模态分解设计方法。搭建转台转速测量实验平台验证希尔伯特-黄角速率测速效果,实验结果证明希尔伯特-黄角速率测量方法对比传统定时测角法的优越性;120(°)/s内的多个转速的实验显示希尔伯特-黄角速率测量方法角速率测量误差小于0.9×10^(-3),角速率测量稳定性优于0.5×10^(-4)。

In this paper,the angular velocity measurement method based on Hilbert-Huang transform principle was studied,which overcame the disadvantages of traditional turntable angular velocity measurement methods,such as method-M and method-T.Based on the analysis of Moirésignal characteristics,the HHT method for Moirésignal characteristics was elaborated in detail.The FPGA-based angular velocity measurement circuit was designed,and the EMD design method in the circuit was explained in detail.A rotating speed measurement experimental platform was built to verify the effect of angular velocity method based on HHT.The experimental results show that the angular velocity measurement method is superior to the traditional methods,and the experimental results of multiple speeds within 120(°)/s show that the rotating speed measurement error of the HHT method is less than 0.9×10^(-3),and the rotating speed measurement stability is better than 0.5×10^(-4).