Development of an efficient method of jamming prediction for designing locating systems in computer-aided fixture design

摘要

In the present study, the mathematical theory of jamming has been developed on the basis of minimum norm principle for workpieces with free-form surfaces. This has laid the basis of a new method proposed as an efficient means of jamming prediction, which is specifically helpful when designing the locating systems in computer-aided fixture design applications. The proposed method determines the contact states between the workpiece and the fixture and checks for the contact mode to predict possible jamming when loading a workpiece into the fixture, based on which the designer can modify the designed locating system in an attempt to avoid jamming. The presented model benefits from the lower computational complexity, quicker response, and more accurate results in comparison with the previous studies in jamming prediction processes. In addition, this method does not require the contact modes to be known beforehand. This is especially crucial at the early stages of the locating system design when the contact mode is not yet clear. Three case studies have been used for evaluating the capabilities of the suggested model, including peg-in-hole, block and palm, and a typical workpiece of 3D free-form model configuration. The results have also been compared with those of previous studies.