像面扫描系统负载非平衡特性分析

Analysis on non-equilibrium load feature of image scanning system

为便于像面扫描控制系统的设计和机械配重,对系统负载的非平衡特性进行研究.首先从凸轮设计入手,简要介绍了相机的工作模式,指出在相机位角扩大监视模式下,凸轮及从动件的重力将会在凸轮扫描平面上产生重力分量.对像面扫描系统负载非平衡特性进行了理论分析.基于电机的数学模型,提出通过电机开环响应曲线测定负载力矩的方法,并分析了测量误差产生的原因.理论分析表明:在相机位角为0°时,凸轮从动件的惯性力造成电机负载力矩不平衡,电机转速越高,负载力矩越大;在相机位角非零时,凸轮及从动件重力在凸轮旋转平面的分量对负载力矩产生影响,且相机位角越大,电机负载力矩越大.像面扫描系统负载非平衡特性的研究将为后续控制系统设计及机械配重提供理论依据.

In order to facilitate the design of control system and mechanical weight-matching,research on the non-equilibrium load feature of imaging scanning systems was carried out. Beginning with the design of the cam,the operating modes of the camera was briefly introduced,and the conclusion that when the camera operated in the position-angle-extension mode,the gravitation of the cam and follower would be projected on the plane of cam scanning was drawn. Academic analysis was done to the non-equilibrium load feature of image scanning systems. Based on the analysis of the motor model,one method to test the load torque through the open-response was induced,and the root of the error was analyzed. The academic analysis shows that when camera position-angle equals to zero,the inertial force of the follower causes the non-equilibrium of motor load torque and the load torque is directionally proportional to the motor rotating speed. Otherwise,the projected part of the gravitation of the cam and follower on the cam scanning plane would affect the load torque. The load torque is also directionally proportional to the position-angle. The research would provide academic reference for the design of the control system and mechanical weight-matching.