Basic research on detection of task errors in robotic manipulation

本文介绍了一种灵巧手操作系统，该系统由一个多指手、一个三维实时立体视觉系统和一个实时手指控制器组成。（一）通过指尖和物体表面之间的滚动接触来操纵被抓取的物体，从而能够以10 ms的速度进行精细和控制。伺服循环时间（2）.三维立体视觉每隔33 ms测量一次被抓取物体的姿态。(3).A提出了一种从力/力矩传感器信号中分离内力和外力的方法。前者是稳定抓取所必需的，后者是所需的操作对象。检测任务错误需要在线推理的任务是如何执行的。这种推理是通过将任务的高级符号意义与手指和被操纵对象的低级运动相结合来进行的。为了使推理，运动原语的多指手的机械装配已经开发。在多指手的机械装配实验中，由于装配过程中存在不可预测的摩擦力，在指尖与被操作物体的接触处经常会出现打滑现象。这一失误导致了任务的错误。为了进行错误检测和恢复，我们利用真实的三维视觉技术开发了一个任务监控系统。这被实现为与任务执行控制处理并行的处理。在最小的时间延迟内检测被操纵物体的姿态错误，而不会损失精细和灵巧的操纵能力。

A dexterous manipulation system has been developed as a test bed for detecting errors of task : the system is conposed of a multi-fingered hand equipped with force/torque sensors on each fingertips, a 3-D realtime stereo vision to measure the pose of a manipuiated object, and a realtime figer controller.Following functions have been developed :(1).The grasped object is manipulated through rolling contacts between fingertips and the surface of the object enabling fine and control with 10ms of servo cycle time.(2).The 3-D stereo vision measures the pose the pose of the grasped object in every 33ms.(3).A method of separating internal forces and external forces from the force/torque sensorsigna1s has been developed. The former is necessary for the stable grasp and the latter is required for desired manipulation of the object.Detection of task errors requires online reasoning of how the task is being executd. This reasoning is made by combining the higher level synbolic meaning of the task and the lower level motion of fingers and the manipulated object. To enable the reasoning, motion primitives of the multi-fingered hand for mechanical assembly have been developed. Peg-insertion, screw-insertion, and screw-rotation have been successfully implenented as motion primitives.In the mechanical assenbly experinents by multi-fingered hand, a slip is very often caused at the contact of the fingertip and the manipulated object mainly because of an unpredictab1e friction force in the assenbly. This slip leads to an error of the task. For the error detection and recovery, a task monitoring system has been developed using the real time 3-D vision. This is implemented as a parallel process with the task execution control process. Detection of errors in the pose of the manipulated object in a minimum time delay without losing fine and dexterous manipu1ation capability.