6自由度索并联机构可以实现空间大范围的6自由度运动,在装配、对接和定位等应用中具有较大的优势。针对柔性绳索容易引起系统振动的特点,对6自由度索并联机构的振动特性进行分析。利用Newton-Euler方法建立系统的动力学模型,对动力学方程线性化获得系统的振动方程。在此基础上,得出各阶固有频率的分布情况,并分析一阶固有频率对结构参数的灵敏度特性。通过绳索受力频谱分析试验,获得6自由度索并联机构试验平台的一阶和二阶固有频率。试验结果与理论计算值接近,验证了所提方法的正确性。
The 6-DOF cable-driven parallel manipulator can achieve a wide range of motion in six degrees of freedom, which leads to the dominant position in the applications of assembling, machining, docking and so on. The 6-DOF cable-driven parallel manipulator bears a concern of possible vibration due to flexible cables. On this point, the vibration characteristic of the 6-DOF cable-driven parallel manipulator is analyzed. The dynamic model of the system is deduced by using Newton-Euler principle. The vibration equation is established by linearizing the dynamic equation about an operating point. On this basis, the natural frequencies are determined and the sensitivities of the first order natural frequency to structure parameters are analyzed. The cable force's spectrum analysis experiment is carded out to acquire the first and the second order natural frequency. The method proposed is verified as the experiment result is closely to theoretical result.