Reconfigurable fixture evaluation for use in automotive light assembly

To make robotics feasible for use in small and medium enterprises (SMEs) several issues have to be addressed. The most obvious is the ability to produce small batches of products with minimal changeover cost and time. In this paper an innovative flexible fixture based on a Gough-Stewart platform called the hexapod is proposed. The fixture is designed to be suitable for a whole family of automotive lights. The main characteristics of the hexapod is its passivity, i.e. the reconfiguration can be performed manually or by using an external mechanism e.g. a robot. Once a desirable configuration is reached a set of hydromechanical brakes is used to hold the mechanism in the desired pose. To show the effectiveness of the hexapods a set of automotive lights assembly in dedicated robot cell experiments were performed. Additionally, positioning repeatability and the locked system stiffness were measured. Finally, a robot cell for a complete light assembly has been implemented together with robot assisted fixture reconfiguration between different light models.