起重机吊重系统状态变量在线软测量方法研究

A study of a method for online soft measurement of state variables of the crane's load-hoisting system

针对工程实际中起重机吊重摆角和摆角角速度不易测量的问题,利用小车位置信息设计了状态观测器,小车吊重系统和观测器构成在线软测量系统。通过引入观测器输出与小车吊重系统输出之间的差值并经过观测器的增益向量调节送至观测器的输入端,将观测器的极点配置在负实轴的同一点上,实现对系统变量稳定、快速软测量。仿真试验表明,在线软测量系统具有较强的鲁棒性;随极点增大,软测量系统对吊重和绳长变化具有更宽的适应范围,但极点过大时,会出现测量误差上冲或下冲现象;当极点确定时,软测量效果对绳长变化比吊重变化敏感。

In response to the long-standing problems, in which the swinging angle of the hoisted load and the velocity of swinging angle is difficult to measure in engineering practice, a state observer is designed by the use of information about the crane trolley＇s position, and as a result, the trolley load-hoisting system combines with the state observer so conceived to form an online soft measurement system. By introducing the difference between the observer＇s output and that of the trolley load-hoisting system, and transmitting it to the output end of the observer upon gain vector adjusting by the observer, the pole points of the observer are configured on the same point at the negative real axle, thereby realizing a stable, fast soft measurement for the system variables. Simulation experiments show that： the online soft measurement system possesses a fairly high level of robustness ; as the pole points grow, however, the soft measurement system grows in the scope of adaptability to changes in the hoisted load and in the length of the hoisting wire rope. But as the pole points overly grow, a sudden increase in measurement errors may occur either way; when the pole points are set, the result of asoft measurement is more sensitive to the length change of the hoisting rope than to the change of the hoisted load.