Experiments, Modeling, and Automatic Planning for Fixturing and Gripping

摘要IIS-9901056 Burdick，JoelCalifornia Institute of Technology$92,265-12 mo.夹具和夹具的实验、建模和自动规划这是为期三年的连续奖项的第一年资助。本研究旨在通过分析与实验相结合的方法，对工件夹持问题及与夹持物体相关的问题进行研究。在自动化夹具规划方面，以前的工作主要是基于柔顺接触的刚体模型或特别模型。这些模型对于涉及大力和精密偏转公差的制造操作来说太不准确了。这项研究的第一个目标是扩展柔顺接触建模的工作，以包括其他重要的接触现象，如非线性柔顺接触中的摩擦效应，以及具有细长内部结构的工件的整体变形。此外，PI计划将相关的接触现象集成到一个有效的可计算模型中。第二个主要目标是建立一个全面的实验系统，这将是第一个测量夹具问题背后的全部物理现象的系统。这些实验不仅应该验证和改进模型，还应该帮助说服固定研究人员和从业者的社区，非线性顺应性模型比当前使用的特别模型更受欢迎。第三个目标是开发基于扩展模型的自动夹具和夹具合成程序。这些算法将能够在存在外部施加的载荷的情况下自动生成保证有意义的性能标准的夹具布置，例如挠度公差。PI还希望包括设计参数，如表面曲率和保证任务性能标准所需的最小夹具数量，这些以前在夹具综合文献中没有涉及到。从长远来看，PI的团队计划利用这些结果来研究夹具加载过程的主动控制，从而从本质上确保零件的准确定位。由于夹具与夹具密切相关，这些结果应该会对部署更复杂的夹具产生更长期的影响。

Abstract IIS-9901056Burdick, JoelCalifornia Institute of Technology$92,265 - 12 mos.Experiments, Modeling, and Automatic Planning for Fixturing and GrippingThis is the first year funding of a three-year continuing award. The research is to investigate analytically and experimentally into problems of workpiece fixturing and related problems of object gripping. Prior efforts in automated fixture planning have largely been based on rigid-body models or ad-hoc models of compliant contact. These models are too inaccurate for manufacturing operations that involve large forces and precision deflection tolerances. The first goal of this research is to extend work on compliant contact modelling to include other important contact phenomena, such as the effect of friction in nonlinearly compliant contacts, and global deformations in workpieces with slender internal structures. Further, the PI plans to integrate therelevant contact phenomena into a single effectively computable model. A second major goal is to construct a comprehensive experimental system that will be the first to measure the complete range of physical phenomena underlying the fixturing problem. These experiments should not only validate and refine the models, but also help convince the community of fixturing researchers and practitioners that nonlinear compliance models are to be preferred over currently used ad-hoc models. A third goal is to develop automated fixturing and gripping synthesis procedures that are based on the extended models. These algorithms will be able to automatically generate fixture arrangements that guarantee meaningful performance criteria, such as deflection tolerance, in the presence of externally applied loads. The PI also wishes to include design parameters, such as surface curvature and the minimal number of fixtures needed to guarantee taskperformance criteria, that have not previously been addressed in the fixture synthesis literature. In the long term, the PI's team plan to use these results to study active control of the fixture loading process so as to inherently ensure accurate part localization. Since fixturing is closely related to gripping, these results should have a longer-term impact on the deployment of more sophisticated gripping devices.