提出一种新型弹性单腿跳跃机器人系统,该机器人由两个驱动臂和一个弹性被动伸缩腿组成,系统只能依靠内部动力学耦合实现动态站立平衡、起跳、稳定连续跳跃运动。给出系统机构模型,分析该系统的变约束特征。该机器人系统在支撑相是二阶非完整约束系统,在飞行相是一阶非完整约束系统。针对这种欠驱动非完整约束动力学系统,采用时变非线性输入变换,提出一种实现垂直方向连续跳跃的运动控制算法。以控制腿部的姿态和振动规律、系统动量为目标实现机器人的全状态稳定控制。通过计算仿真模拟,验证提出的运动控制方案是可行的。该研究以探索弹性欠驱动机械系统振动能量循环利用技术为目标,研究结果对设计新型弹性欠驱动机械系统以及探索它在航天领域的应用具有一定参考价值。
A new model of elastic one-legged hopping robot is proposed. The hopping robot is constructed by two actuated arms and an elastic passive telescopic leg. Motion control of the one-legged robot such as stance balance, lift-off and hopping stably depends on the dynamics coupling of the system. The mechanism model of the robot and the variable constraints property of it are analyzed. It is shown that the robot is a nonholonomic system, which is second order in stance phase, first order in flight phase. A motion control algorithm is proposed for hopping control in vertical direction based on nonlinear transformation of inputs for this kind of underactuted nonholonomic dynamic system. The whole state variables are controlled by considering the orientation of the leg, the vibration of the linear spring, and the momentum of the robot system in horizontal direction. Some simulations test the feasibility of the control method numerically. The research results are helpful for investigating the techniques to save energy of the elastic underactuated mechanical system by utilizing the vibration of compliant components, thus the research can be used for reference in designing other new elastic underactuated mechanical systems and their application in space field.