Virtual Constraints: A New Paradigm for the Control of Motion

这一建议涉及到一种新的非线性动力系统运动控制范例的研究。运动控制问题涉及到设计算法，使一个或多个动态系统表现出规定的行为。运动控制问题广泛存在于工程的各个领域，包括多足机器人的运动、自主飞行器的飞行控制以及地面、空中和空间飞行器的编队控制。传统的运动控制方法对环境中的干扰和不确定性的鲁棒性有限，因此不能满足新兴的应用，如多腿机器人的运动和航天器编队的协调。在过去的十年里，一种新的运动控制范式已经出现，它有可能克服传统方法的局限性，并可能使新一代运动控制算法成为可能。这种模式依赖于虚拟约束的概念，虚拟约束是对控制系统的状态的约束，这种约束不是物理上存在的，但可以通过反馈控制来实施。虚拟约束的概念已经被成功地用于诱导两足机器人稳定的行走步态，但要使虚拟约束范例超越两足机器人的运动，并变得足够普遍，以适用于大量的工程问题，仍有许多研究要做。拟议的研究计划将为一类机械系统和自动驾驶车辆的虚拟约束的系统理论奠定基础，并将研究其在卫星编队控制和机器人遥操作中的应用。这个研究项目的最终目标是一套通用的工具来自动生成运动基元的集合。每个运动基元将与一个虚拟约束相关联，并将对应于所需的行为。非专业用户然后将能够选择运动基元序列以在动力系统中诱导复杂的行为。这一研究计划的结果可能在机器人、航空航天工程和康复工程等不同领域具有相当大的实际意义。

This proposal concerns the investigation of a new paradigm for motion control in nonlinear dynamical systems. The motion control problem involves designing algorithms to make one or more dynamical systems exhibit a prescribed behaviour. Motion control problems abound in all areas of engineering, and include locomotion in multi-legged robots, flight control of autonomous aircrafts, and formation control of terrestrial, aerial, and space vehicles. The traditional motion control methodology has limited robustness against disturbances and uncertainties in the environment, and it is therefore inadequate to address emerging applications such as locomotion in multi-legged robots and coordination of spacecraft formations. In the last decade, a new paradigm for motion control has emerged which has the potential to overcome the limitations of traditional methods, and may enable a new generation of motion control algorithms. This paradigm relies on the concept of virtual constraint, a constraint on the states of a control system that does not physically exist, but can be enforced via feedback control. The notion of virtual constraint has been used with great success to induce stable walking gaits in biped robots, but much research remains to be done to make the virtual constraint paradigm go beyond biped locomotion, and become general enough to be applicable to a vast array of engineering problems. The proposed research program will lay the foundations for a systematic theory of virtual constraints for a class of mechanical systems and autonomous vehicles, and will investigate its applications to the control of satellite formations and robotic teleoperation. The ultimate goal of this research program is a set of general tools to automatically generate a collection of motion primitives. Each motion primitive will be associated with a virtual constraint, and will correspond to a desired behaviour. An inexpert user will then be able to select a sequence of motion primitives to induce complex behaviours in the dynamical system. The outcomes of this research program may have considerable practical implications in areas as diverse as robotics, aerospace engineering, and rehabilitation engineering.