Geometric Methods in the Control of Bipedal Walking Robots

该项目的目标是利用几何约简的概念开发双足步行机器人的控制算法。几何约简利用了两足机器人动力学方程的对称性，方便了低维模型的计算，便于分析和控制设计。目标是使为二维或平面两足动物开发的控制概念能够应用于完全三维的两足动物。这种方法大大降低了三维步行机器人控制问题的复杂性。该项目还将研究腿部参数（如腿长和腿质量）的不对称性对被动步态的存在和特性的影响。初步研究表明，腿部参数（如腿部质量）的不对称导致步态的质变，如倍周期分岔和混沌运动。这项研究的成果包括新的控制算法、新的仿真模型和用于仿真数据可视化的图形仿真工具。这项研究的实际应用是在行走机器人的设计，有改进的性能能力比现有的机器。目前的步行机器人由于能量利用率低，行走距离有限，并且在不平坦的地形上行走的能力有限。一旦将现有理论工具的全部力量用于本项目的分析和设计问题，就会产生更实用、更高效的步行机。该项目开发的工具也将有助于更好地理解人类运动，这将导致生物力学和生物医学的应用，如设计改进的假肢装置，开发老年人跌倒预防计划和康复技术。研究参数不对称的两足动物是为了了解人类步态不对称对行走稳定性、性能和步态障碍的影响。我们的研究结果还将用于为初中生和高中生制作演示和演讲，作为招聘工具。我们过去的经验表明，机器人技术是吸引和留住工程专业学生的绝佳工具。

The object of this project is to develop control algorithms for bipedal walking robots using concepts of geometric reduction. Geometric reduction takes advantage of certain symmetry properties in the dynamic equations of bipedal robots and facilitates the computation of lower dimensional models for analysis and control design. The goal is to enable control concepts developed for two-dimensional, or planar, bipeds to be applied to fully three-dimensional bipeds. In this way, the complexity of the control problem for three-dimensional walking robots is greatly reduced. The project will also investigate the effects of asymmetries in leg parameters, such as leg length and leg mass, on the existence and properties of passive gaits. Preliminary investigations indicate that asymmetry in leg parameters, such as leg mass, results in qualitative changes in gait, such as period-doubling bifurcations and chaotic motion. Deliverables from this research include new control algorithms, new simulation models and graphical simulation tools for visualization of simulation data.The practical application of this research is in the design of walking robots that have improved performance capabilities over existing machines. Current walking robots have limited range due to poor energy utilization and are limited in their ability to navigate uneven terrain. More practical and more efficient walking machines will result once the full power of available theoretical tools is brought to bear on the analysis and design questions in this project. The tools developed in this project will also contribute to a better understanding of human locomotion, which will result in applications in biomechanics and biomedicine, such as the design of improved prosthetic devices, the development of falls prevention programs for the elderly, and rehabilitation techniques. The study of bipeds with parameter asymmetry is motivated by the desire to understand the effect of asymmetry of human gait on walking stability, performance, and gait disorders. Our research results will also be used to create demonstrations and presentations for middle school and high school students to be used as recruiting tools. Our past experience has shown that robotics is an excellent vehicle to attract and retain students in engineering.