全柔性机器人机构结构动力学分析方法研究

RESEARCH ON STRUCTURAL DYNAMICS OF A GENERAL FULLY COMPLIANT ROBOTIC MECHANISM

全柔性机器人机构是一种新型机构,多用于高精度的场合。由于其动力学性能会影响其终端的定位精度,因此,有必要对其结构动力学进行研究。具体将全柔性机器人机构作为结构体,分别采用理论简化建模、有限元和试验测试三种方法对其进行了结构动力学方面的研究,并进行了实例分析。首先通过理论简化建模计算出全柔性机器人机构的固有频率,采用商用有限元软件对该机构进行了模态分析,并对该机器人的模态频率进行了试验测试。有限元分析及试验结果均表明了简化模型计算结果有一定的精度。

The fully compliant robotic mechanism is a new type of mechanism, and it is widely used in the high-precision applications. Considering that some imperfect structural dynamic characteristics of a fully compliant robotic mechanism such as its lower natural frequency may bring a negative influence on its positioning accuracy, it is necessary to discuss the structural dynamics of the mechanism in detail. To specify it, three meth- ods to analyze the structural dynamics of a general fully compliant robotic mechanism, i.e. simplified theoretical modeling, Finite element analysis (FEA), and experimental measurement are addressed. In addition, taking a concrete fully compliant robotic mechanism (3-RRPR mechanism) for instance, its simplified model is formulated to predict the natural frequencies of the mechanism; The modal analysis of the mechanism is carried out by means of a finite element method. Experiments are conducted to measure the modal frequencies of the robot. The results obtained from simplified formulation, FEA and experiments are analyzed. Results of both FEA and experiment verify the accuracy of the theoretical model.