一种用于运动目标捕获的行星轮差动式欠驱动臂

为解决运动目标捕获过程中的碰撞问题，采用欠驱动自适应原理研制了具有碰撞能量吸收能力的机械臂。三自由度的机械臂由2个电机驱动：基关节由单个电机驱动；中关节和末关节由一个单输入双输出行星轮组完成动力分配。在机械臂捕获运动目标过程中，碰撞产生的部分冲击能量通过欠驱动行星轮组传递到末关节，转化为关节动能。依靠欠驱动机械系统完成对碰撞的响应，解决了控制系统因时延而无法快速对碰撞进行响应的难题。为完成对目标的抓取，基于阻抗控制提出了机械臂运动目标捕获控制算法。运动目标捕获实验验证了机械臂对碰撞的快速响应能力及运动目标捕获控制算法的可行性。

Differential planetary gears based underactuated arm for capturing moving target

A novel underactuated robotic arm was proposed for moving target capturing, which has the capability of collision energy absorption. The proposed underactuated three-degree-of-freedom robotic arm has base joint, median joint and distal joint, and three joints are driven by two actuators. The base joint is driven by a single motor. The median joint and the distal joint employ a set of one-input-dual-output planetary gears to distribute power. Upon the occurrence of a collision in the process of capturing a moving target, part of the collision energy can be transmitted to the distal joint through the planetary gears as kinetic energy. Even though the time delay exists in the control system, the underactuated joints can also move cooperatively with the collided target through the mechanical passive response. Moreover, the impedance-based control algorithm of the underactuated robotic arm is presented for capturing the target after the collision. Capture experiment for moving target was carried out to confirm desirable characteristics of the proposed arm and feasibility of the control strategy.