College of Mechanical Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China.
Sensors (Basel). 2011;11(12):11761-73. doi: 10.3390/s111211761. Epub 2011 Dec 16.
A novel design of force to rebalance control for a hemispherical resonator gyro (HRG) based on FPGA is demonstrated in this paper. The proposed design takes advantage of the automatic gain control loop and phase lock loop configuration in the drive mode while making full use of the quadrature control loop and rebalance control loop in controlling the oscillating dynamics in the sense mode. First, the math model of HRG with inhomogeneous damping and frequency split is theoretically analyzed. In addition, the major drift mechanisms in the HRG are described and the methods that can suppress the gyro drift are mentioned. Based on the math model and drift mechanisms suppression method, four control loops are employed to realize the manipulation of the HRG by using a FPGA circuit. The reference-phase loop and amplitude control loop are used to maintain the vibration of primary mode at its natural frequency with constant amplitude. The frequency split is readily eliminated by the quadrature loop with a DC voltage feedback from the quadrature component of the node. The secondary mode response to the angle rate input is nullified by the rebalance control loop. In order to validate the effect of the digital control of HRG, experiments are carried out with a turntable. The experimental results show that the design is suitable for the control of HRG which has good linearity scale factor and bias stability.
本文提出了一种基于 FPGA 的半球谐振陀螺（HRG）力再平衡控制的新型设计。该设计利用驱动模式下的自动增益控制环路和锁相环路配置，同时在感测模式下充分利用正交控制环路和再平衡控制环路来控制振荡动力学。首先，从理论上分析了具有非均匀阻尼和频率分裂的 HRG 的数学模型。此外，描述了 HRG 的主要漂移机制，并提到了抑制陀螺漂移的方法。基于数学模型和漂移机制抑制方法，采用四个控制环路通过 FPGA 电路来实现 HRG 的操作。参考相位环路和幅度控制环路用于保持主模态以恒定幅度在其自然频率处振动。通过从节点的正交分量反馈直流电压的正交环路可以很容易地消除频率分裂。通过再平衡控制环路消除了对角速度输入的二次模态响应。为了验证 HRG 数字控制的效果，使用转台进行了实验。实验结果表明，该设计适用于具有良好线性标度因数和偏置稳定性的 HRG 控制。
