多自由度双柔性杆月壤取样器

Multi-DOF lunar sampler with double flexible rod

针对小型单杆式柔性臂月壤取样器的不足,设计并实现了一种多自由度双柔性杆月壤取样器.首先介绍了该取样器的机械结构设计,并在结构设计的基础上采用D-H法则进行了多自由度机械臂的坐标设定和运动学分析.由于该月壤取样器采用柔性的开口圆柱形薄壳杆作为其取样臂,所以在运动学分析中加入了柔性变量,以符合实际控制精度的要求.实验证明引入柔性变量的运动学算法能够对取样器进行满足精度要求的控制,其取样头部最大定位误差为2.8mm.多自由度双柔性杆月壤取样器在保留了小型单杆式柔性臂月壤取样器优点的基础上,提高了工作稳定性和取样的下钻力,实验确定了双柔性杆在取样长度为700 mm时能够承受的最大轴向力为36.4 N,满足工作需求.

Considering the disadvantages of the small one-flexible-rod lunar sampler,a double-flexible-rod multi-degree-of-freedom（multi-DOF） lunar sampler is developed.First,the design of the mechanical structure is introduced.Moreover,the kinematics is built based on the mechanical structure and the D-H rules.Since the opening cylindrical shell is adopted as the sampling arm,the flexible variables are introduced into the kinematical analysis to satisfy control requirements.The experiments show that the flexible kinematical algorithm is suitable for the control of the sampler and the control accuracy is greatly improved.The maximum position error at the sampling head is 2.8 mm.The working stability and the drilling power of the sampler are also improved compared with the small oneflexible-rod lunar sampler.The maximum axial force that the flexible arm can bear is 36.4 N when the length of the flexible arm is 700 mm,which meets the requirements of working.