考虑安装基座影响的光电平台等价捷联惯性稳定控制

采用陀螺仪直接测量光电平台内部载荷的惯性角速度构建反馈,可以在运动载体上控制视轴惯性角速度,实现稳定成像。陀螺捷联惯性稳定控制能够构建前馈,有效提高系统带宽、减小控制误差,但对陀螺安装位置有要求。本文提出了在陀螺直接反馈的机械安装条件下等价捷联稳定的控制方法,并考虑平台基座约束条件建立了动力学模型。该模型显露了光电平台基座安装刚度引入的谐振问题。针对被控对象中的一对谐振和反谐振环节,基于稳定的零极点对消设计滤波器消除谐振。综合利用陀螺直接测量的框架惯性角速度和编码器测量的机械框架相对转角构建等价捷联惯性稳定回路。在等价捷联惯性稳定回路中,采用内回路干扰抑制结合基于逆模型前馈的复合控制方法,有效拓展控制带宽,提高对指令的跟踪精度和对载体姿态晃动的隔离性能。仿真和实验结果表明:该方法有效抑制了安装基座弹性约束力矩的谐振,且与陀螺直接反馈控制相比性能更优。对幅值为1(°)/s、频率为1 Hz的典型正弦角速度指令进行跟踪,均方根误差由1.75(°)/s减小到0.23(°)/s,在1 Hz处扰动隔离度由18%减小到2%。

Equivalent strapdown inertial stability control of photoelectric platform considering the effect of mounting base

By using a gyroscope to directly measure the inertial angular velocity of the load inside a photoelectric platform to construct feedback, stable imaging can be achieved by controlling the inertial angular velocity of light of sight on the moving carrier. The gyroscope strapdown inertial stability control method can be used to construct the feedforward, increase the system bandwidth effectively, and minimize control error. However, there are requirements for the gyroscope installation position. We have proposed an equivalent strapdown stability control method, which satisfies the mechanical installation conditions with direct gyroscope feedback. The method establishes a dynamic model considering the constraints of the mounting base. The model reveals the resonance problem caused by the installation stiffness of the photoelectric platform base. For a pair of resonance and antiresonance, the filter to eliminate resonance based on a stable pole-zero cancellation method was designed. An equivalent strapdown inertial stability loop was constructed with the inertial angular velocity of the frame measured using the gyroscope, and the relative rotation angle of the mechanical frame measured using an encoder. In the loop above, we combined the inner loop interference suppression with the compound control method usingthe inverse model feedforward, which successfully expanded the system bandwidth, improved the tracking precision of the command, and enhanced the isolation performance. The simulation and experimental results show that the proposed method can effectively suppress the resonance of the elastic restraint moment of the mounting base and exhibit better performance than the gyroscope direct feedback control. For tracking a typical sinusoidal angular velocity command with an amplitude of 1(°)/s and a frequency of 1 Hz, the root mean square error of the system decreased from 1.75 to 0.23(°)/s, and the disturbance isolation decreased from 18% to 2%.