Exploratory Research on Controlled Passive Haptic Displays

机器人设备自主移动，向其环境中的物体施加力，对施加在它们身上的力做出反应，以达到所需的速度、位置或阻抗。传统的机器人使用电机(有源功率转换装置)来实现这些目的。这项研究考察了一种被动的替代方案，以提供抵抗由人类或其他主动主体发起的运动的力，以用于远程或虚拟环境的触觉显示或用于引导主体的运动。最终的应用是虚拟现实显示、远程操作、手术辅助、锻炼和康复。无源方法的优点包括消除了有源设备的固有危险，以及在必须提供电源时降低了成本和复杂性。这项研究将使用最近构建的被动臂原型PTER(被动式轨迹增强机器人)作为测试案例。PTER有两个自由度，通过电磁刹车耦合，这样能量就可以以受控的方式从一个轴转移到另一个轴。这项研究将探索控制算法的理论和实践方面，以实现这种耦合，用于触觉显示，如PTER。被动执行器的局限性决定了控制的独特性和挑战性。将对控制算法进行测试，以确定受控被动设备相对于两种替代方案的有效性：(1)直接物理显示器(不可编程)和(2)在现有运动学相同的机器人上的电动虚拟显示器。对业绩的衡量既有定量的，也有主观的。所跟踪的轨迹的准确性和环境阻抗(力-速度关系)的表示的准确性可以被定量评估。将聘请人工操作员对被动显示的效果进行更主观的评估。例如，S的任务将是按照设备赋予的感觉遵循一个虚拟迷宫。

Robotic devices move autonomously, apply forces to objects in their environment, react to forces applied to them to achieve desired velocities, positions or impedances. Conventional robots use motors (active power transduction devices) to achieve these ends. This research examines a passive alternative to provide forces to resist motion initiated by a human or other active agent for the purpose of haptic display of remote or virtual environments or for guidance of the agent's motion. Ultimate applications are for virtual reality displays, for teleoperation, for surgical assistance, for exercise and for rehabilitation. The advantages of a passive approach include the elimination of inherent dangers of an active device and the reduction of cost and complexity when a power supply must be provided. This research will utilize a recently constructed prototype passive arm known as PTER (Passive Trajectory Enhancing Robot) as a test case. PTER has two degrees of freedom, coupled via electromagnetic brakes so that energy can be diverted in a controlled manner from one axis to the other. The research will explore the theoretical and practical aspects of the control algorithms to accomplish this coupling for purposes of haptic display such as PTER. The limitations of the passive actuators provide the uniqueness and challenge of the control. The control algorithm will be tested to determine effectiveness of the controlled passive device against two alternatives: (1) a direct physical display (not programmable) and (2) an electrically powered virtual display on an available kinematically identical robot. The measures of performance be both quantitative and subjective. The accuracy of the trajectory followed and the accuracy of representation of an environment's impedance (force-velocity relationship) can be quantitatively evaluated. Human operators will be employed to provide a more subjective evaluation on the effectiveness of the passive display. Example task s will be to follow a virtual maze as guided by the feel imparted by the device.