Zhang Fuli, Yuan Zhaohui
School of Automation, Northwestern Polytechnical University, Xi'an 710072, China.
Sensors (Basel). 2021 Feb 22;21(4):1522. doi: 10.3390/s21041522.
The flexible manipulato is widely used in the aerospace industry and various other special fields. Control accuracy is affected by the flexibility, joint friction, and terminal load. Therefore, this paper establishes a robot dynamics model under the coupling effect of flexibility, friction, and terminal load, and analyzes and studies its control. First of all, taking the structure of the central rigid body, the flexible beam, and load as the research object, the dynamic model of a flexible manipulator with terminal load is established by using the hypothesis mode and the Lagrange method. Based on the balance principle of the force and moment, the friction under the influence of flexibility and load is recalculated, and the dynamic model of the manipulator is further improved. Secondly, the coupled dynamic system is decomposed and the controller is designed by the multivariable feedback controller. Finally, using MATLAB as the simulation platform, the feasibility of dynamic simulation is verified through simulation comparison. The results show that the vibration amplitude can be reduced with the increase of friction coefficient. As the load increases, the vibration can increase further. The trajectory tracking and vibration suppression of the manipulator are effective under the control method of multi-feedback moment calculation. The research is of great significance to the control of flexible robots under the influence of multiple factors.
柔性机械手在航空航天工业和其他各种特殊领域中得到了广泛应用。控制精度受到柔性、关节摩擦和末端负载的影响。因此，本文建立了在柔性、摩擦和末端负载耦合作用下的机器人动力学模型，并对其控制进行了分析和研究。首先，以中心刚体、柔性梁和负载的结构为研究对象，采用假设模态法和拉格朗日方法建立了带末端负载的柔性机械手动力学模型。基于力和力矩的平衡原理，重新计算了柔性和负载影响下的摩擦力，进一步完善了机械手的动力学模型。其次，对耦合动态系统进行分解，并采用多变量反馈控制器设计控制器。最后，以MATLAB为仿真平台，通过仿真对比验证了动态仿真的可行性。结果表明，随着摩擦系数的增大，振动幅度可以减小。随着负载的增加，振动会进一步增大。在多反馈力矩计算的控制方法下，机械手的轨迹跟踪和振动抑制是有效的。该研究对多因素影响下的柔性机器人控制具有重要意义。
