NRI: Biologically-inspired, hybrid quadruped robot control

这个研究项目是关于为有腿机器人设计更好的腿。当机器人需要在崎岖的地形上移动时，比如在灾区寻找受害者时，腿式机器人比轮式或履带式机器人更有优势。他们可以更容易地穿越这样的地形，例如，跨过倒下的横梁和砖块。然而，有腿的机器人本质上更复杂。它们有更多的关节，更难控制。该项目的目标是利用来自大自然的想法来克服这些困难。四足动物的形状和顺应性在它们小跑或疾驰时被动地增加了它们的稳定性。这些想法将被整合到一个四足机器人中，使其运动能力更加强大。从自然界复制的一个主要问题是动物能够自适应地改变关节和腿的顺应性。这是这个项目的主要目标。除了研究目标之外，该项目还包括研究生和本科生的教育内容，以及向中学的推广。本项目采用的方法将简化四足机器人的控制，通过使用方向柔性腿来被动稳定机器人在动态步态下，如小跑。主动控制刚度和关节平衡位置将允许自适应的参数变化，以改变地形，步态和机器人的变化（例如携带负载）。该系统将采用混合控制器，在步态中使用被动、欠驱动腿，但主动改变被动特性。机器人的稳定性是通过机器人身体的俯仰和横摇来衡量的。自适应控制器将通过改变关节刚度、平衡角度和每个关节的位置来最小化期望的俯仰和滚转误差。

This research project is about designing better legs for legged robots. When a robot needs to move across rough terrain, as would be the case when searching for victims in a disaster area, legged robots have advantages over wheeled or tracked robots. They can traverse such terrain more easily, for example, stepping over fallen beams and bricks. However, legged robots are inherently more complex. They have many more joints and are more difficult to control. The goal of the project is to use ideas from nature to overcome some of these difficulties. The shape and compliance of four-legged animals adds to their stability passively when they trot or gallop. These ideas will be incorporated into a four-legged robot, making its locomotion abilities more robust. A major issue to duplicate from nature is the animal's ability to adaptively change the compliance of their joints and legs. This is a primary objective of this project. In addition to the research objectives, this project also includes educational components involving graduate and undergraduate students as well as outreach to secondary schools.The approach taken in this project will simplify the control of quadruped robots by the use of directionally compliant legs to passively stabilize the robot under dynamic gaits such as trotting. Active control of the stiffness and joint equilibrium positions will allow for adaptive parameter changes to changing terrain, gaits, and robot variation (carry a load for example). The system will employ a hybrid controller using passive, under-actuated legs during gaits, but actively changing the passive characteristics. Stability of the robot is measured by the pitch and roll of the robot body. The adaptive controller will minimize errors in the desired pitch and roll by changing the joint stiffness, equilibrium angles and positions of each joint.