Designing Fast Parts Feeders Using Acceleration-Based Non-Prehensile Manipulation

本研究的目标是设计快速、精确的零件送料机，并改善机器人的无摩擦操作。 这两个目标密切相关。 一个好的架构， 零件进给器通过沿进给器沿着流水线布置快速动作的低自由度操纵器而利用了平行性和动态接触。 人类或动物对物体的非接触性操纵通常涉及动态接触，其中物体经历一系列部分抓握，在各种接触之间来回移动。 通过运动和加速触点来控制零件的运动是实现零件快速非接触加工的关键。 本研究建立了一套分析工具，描述了加速约束的运动如何影响被操纵部件所感受到的有效力。 这些分析仔细考虑了接触和摩擦，以及已经作用在零件上的任何力，例如重力。 由此产生的工具将允许规划者为送料器产生控制算法，从而随着零件形状的变化或错误的出现而动态地重新配置送料器。 在传统的喂料器设计中，任务的大部分机械结构已经被编译成硬件，以固定喂料器门和定向形状的形式。 在另一个极端，通用机器人遭受了太多的通用性和太少的可靠软件。 一个重要的中间体系结构由软件控制下的一系列简单的机械手组成。 这项研究将探索饲养员使用 手掌操作范例。 当零件通过送料器时，一系列低自由度的装置将使用非接触式动态接触来定位零件。 由于装置的配置和运动是在软件控制下的，并且由于装置由于具有低自由度而易于编程，因此进料器应当能够相对容易地适应最后一分钟的零件更换。

The goals of this research are to design fast, precise parts feeders and to improve nonprehensile robotic manipulation. The two goals are closely related. A good architecture for a parts feeder exploits both parallelism and dynamic contact, by pipelining fast-acting low-degree of freedom manipulators along the feeder. Nonprehensile manipulation of objects by humans or animals often involves dynamic contact in which the object undergoes a series of partial grasps, shuffled back and forth between various contacts. The key to fast nonprehensilemanipulation of parts is controlling part motions through moving and accelerating contacts. This research builds a set of analysis tools that describe how the motions of accelerating constraints affect the effective forces felt by the parts being manipulated. These analyses take careful account of contact and friction, plus any forces already acting on the part, such as gravity. The resulting tools will allow a planner to produce control algorithms for the feeder, and thus dynamically reconfigure the feeder as part shapes change or errors appear. In traditional feeder design, much of the mechanics of the task has been compiled into hardware, in the form of fixed feeder gates and orienting shapes. At the other extreme, general purpose robots have suffered from too much generality and too little reliable software. An important intermediate architecture consists of a sequence of simple manipulators under software control. This research will explore feeders using the palm manipulation paradigm. As parts pass through a feeder, a sequence of low-degree of freedom devices will orient the parts using nonprehensile dynamic contacts. Since the configurations and motions of the devices are under software control and since the devices are easy to program by virtue of having low degrees of freedom, the feeder should be able to accomodate las t-minute part changes with relative ease.