吊装绳牵引并联起重机器人的建模分析

Modeling of A Wire-Driven Parallel Crane Robot for Containers Handling

提出一种6自由度的绳牵引并联起重机器人,以取代现有的轨道吊.通过对绳牵引并联起重机器人进行构型配置并建模后发现,其动力学系统是具有8个输入量、6个状态量和输出量的冗余驱动的非线性系统.将非正则反馈线性化控制器引入到该系统中,得到一个线性化的系统.选择适当的输入控制律,即可得到一个关于轨迹误差的二阶常微分方程.在选择合适的反馈增益的基础上,可实现渐近稳定的吊运轨迹跟踪控制.仿真结果表明,吊具在x和y方向上的轨迹的稳态误差为零,但在z方向上的轨迹始终存在一个固定的稳态误差,必须通过改进系统的控制器来解决.

A 6-degree-of-freedom wire-driven parallel crane robot for containers handling replacing rail-mounted gantry cranes is presented. The mechanism configuration of the wire-driven parallel crane robot is given. After the modeling of the crane robot system, it is found that its dynamic modeling is a redundantly actuated nonlinear system with 8 inputs, 6 states and 8 outputs. A non-regular feedback linearization controller is used to linearize the system and an ordinary differential equation about the error trajectory of the payload is obtained after the use of a suitable input control law for the linearized system, which the asymptotical stability of the trajectory tracking of the payload can be realized if the feedback gains are selected. The simulation results have shown that the steady-state errors of the tracking trajectory along x and y directions tend to zero and that along z direction keeps a constant value which should be eliminated by improving the controller.