提出了凸轮驱动的线阵CCD像面动态扫描拼接方法以扩大遥感仪器的覆盖宽度, 并对系统负载非平衡特性及其多模控制算法进行了分析。讨论了现有拼接方法的优缺点, 进而引入凸轮驱动的动态扫描拼接方法。该方法采用电机和凸轮作执行机构, 电机做匀速旋转运动, 通过凸轮带动多个线阵CCD做往复直线运动, 实现动态扫描拼接。为了提高CCD成像质量, 从理论上对凸轮结构的特殊性、平台姿态角及相机方位角造成的系统负载非平衡特性进行了分析, 结果表明: 平台俯仰角对负载非平衡特性影响较小, 可以忽略; 当平台横滚角和相机位角之和非零时, 负载力矩在凸轮升程段和回程段表现出不同的特性。针对凸轮升程段和回程段采用相同控制器时凸轮转速在两阶段存在转速降的情况, 提出了变输入的多模控制方法, 并进行了相关实验。结果表明: 变输入的多模控制方法可有效消除凸轮转速在升程段和回程段存在的转速降, 且在从动件匀速段的凸轮稳速精度达到0.48%。该方法简单、方便, 易于工程实现。

Linear CCD dynamic scanning assembly actuated by a cam was proposed to extend the coverage of the remote sensing instruments, and the non-equilibrium load feature of the system and related multi-model control arithmetic were analyzed in detail. After discussing the strongpoint and shortcoming of existing methods, the dynamic scanning assembly actuated by a cam was introduced. In this method, a motor and a cam were used as the acting devices. The motor rotated at a constant speed and the linear CCDs were driven by the cam to reciprocate on the focal plane. The non-equilibrium load feature of the system was introduced by the special structure of the cam, platform attitude angles and the camera azimuth. As the non-equilibrium load feature could effect the CCD image, it was analyzed in theory. Analysis results show that the platform pitch angle affects slightly the non-equilibrium load feature, so it could be ignored. When the sums of platform roll angle and camera azimuth are not zero, the load torque shows different features in the lift section and return section of the cam. In consideration of that the cam speed was different in the lift section and return section of the cam when the same controller was used, one multi-model controlling method with varying input signals was imported. The relative experiments were performed and the results show that the difference between camspeeds in the lift section and return section can be eliminated effectively by the multi-model controlling method with varying inputs. The rotate speed precision of the cam is 0.48% in the uniform section of the follower. It concludes that this method is simple and convenient to be realized.