Experiments, Modeling, and Automatic Planning for Fixturing and Gripping

摘要：加州理工学院伯迪克分校92265 - 12美元。夹具和夹具的实验、建模和自动规划这是一项为期三年的持续奖励的第一年资助。本研究的目的是对工件的夹具问题和物体夹持的相关问题进行分析和实验研究。以前在自动化夹具规划方面的努力很大程度上是基于刚体模型或柔性接触的特别模型。这些模型对于涉及大力和精密挠度公差的制造操作来说太不准确了。本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影响，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，这将是第一个测量固定问题背后的所有物理现象的系统。这些实验不仅应该验证和改进模型，而且还应该帮助说服固定研究人员和实践者社区，非线性顺应性模型比目前使用的特设模型更可取。第三个目标是开发基于扩展模型的自动化夹具和夹持综合程序。这些算法将能够自动生成夹具安排，保证有意义的性能标准，如挠度公差，在外部施加载荷的存在。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，这些在夹具综合文献中没有得到解决。从长远来看，PI团队计划利用这些结果来研究夹具加载过程的主动控制，从而从本质上确保精确的零件定位。由于夹具与夹持密切相关，这些结果应该对更复杂的夹持设备的部署产生长期影响。

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.