基于串联弹性驱动器的单腿跳跃机器人轨迹规划和跟踪控制方法研究

Due to the powerful ability of one-legged hopping robot to terrain adapted, it becomes a hot research topic in the field of mobile robot. It has a wider significance for theoretical research and application. Faced on controllable movement problems on one-legged hopping robot with the series elastic actuator (SEA), the project aims to study the hopping mechanism and its interactions with the environment. Meanwhile, by analyzing the system states and the switching among each state, the hybrid dynamic model is built for one-legged hopping robot with series elastic actuator, which reveals the inner mechanism of hopping process. Based on the dynamic model, the period closed trajectory under the dynamic constraint within one state as well as switching between the states is obtained by state space search methods. Thus, the obtained trajectory is involved as the initial value for trajectory planning by virtual restraint approach to reduce the search spaces to a finite-dimensional, which obtained approximately periodic solutions. Furthermore, according to the characteristics of the SEA, combined with dynamics model and planned trajectory for the one-legged hopping robot obtained above, the position tracking controller as well as torque tracking controller are developed to make the one-legged hopping robot follow the desired trajectory and accomplish the autonomous movement. Finally, the methods proposed for this project are validated by the simulation platform and experimental platform of one-legged hopping robot with SEA built by the group.

单腿跳跃机器人由于其较强的地形适应能力一直成为移动机器人领域中的研究热点，有着较高的理论研究与应用价值。面向基于串联弹性驱动器的单腿跳跃机器人的受控运动问题，研究单腿跳跃机器人跳跃机理及其与环境间的相互作用关系，对各个状态以及状态间切换构建基于串联弹性驱动器的单腿跳跃机器人混合动力学模型，进而揭示跳跃运动的内在机理。在此基础上，利用空间搜索方法寻求单腿跳跃机器人不同状态下以及状态切换过程中满足动力学模型约束的周期闭轨迹，将得到的轨迹作为初值进行基于虚约束的周期闭轨迹搜索，将寻解空间降低到有限维，从而近似求得周期解。通过对串联弹性驱动器特性的分析，结合单腿跳跃机器人动力学模型和规划轨迹，设计受控的位置跟踪和力矩跟踪算法，使得单腿跳跃机器人以较高精度完成规划轨迹，进而实现自主运动。最后，基于自主开发的仿真平台与基于串联弹性驱动器的单腿跳跃机器人实验平台，对本项目提出的理论方法进行验证。

由于单腿跳跃机器人较强的灵活性和环境适应能力，在考古探测、军事侦察以及反恐活动等领域有着广阔的应用前景。串联弹性驱动器具有自身低阻抗、体积小、能量密度高、力输出稳定以及缓冲外部冲击载荷的优点，能很好地弥补传统驱动技术的不足，对于足式机器人具有先天的优势。然而，精确跟踪控制是实现单腿机器人连续稳定跳跃的前提条件，虽然弹性元件的引入可以改善系统力学特性，但是由于系统刚度的下降使得串联弹性驱动器的精确跟踪控制问题也变得更加复杂。.为此，本项目针对基于串联弹性驱动器的单腿跳跃机器人系统展开了深入研究，所取得的研究成果如下：1）构建了基于串联弹性驱动器的单腿跳跃机器人混合动力学模型，自主开发了基于串联弹性驱器的单腿跳跃机器人仿真平台与实验平台。2）针对单腿机器人的跳跃运动，提出了稳定前向跳跃及变速过渡跳跃两种不同的运动状态，并分别对其步态规划问题做了详细的数学描述。3）针对串联弹性驱动器的位置跟踪控制问题，设计了考虑未建模动态与非匹配扰动的控制方法以及抑制负载端的残余抖动的控制方法，实现了负载端的精确位置跟踪和抖动抑制。4）针对串联弹性驱动器的力/力矩跟踪控制问题，设计了基于负载端运动观测与补偿的控制方法以及基于有限时间输出反馈的控制方法，提升了控制系统的暂态控制性能，对负载变化表现出很好的鲁棒性，并在自主搭建的实验平台上进行了实验验证。.项目组发表/录用论文22篇，包括SCI源刊论文5篇，授权发明专利3项，登记软件著作权1项。