A prototype of a controllable hinge mechanism for the deployment of a satellite membrane antenna.

摘要

One of the main goals in improving space-bound deployable structures is to find novel ways, materials and mechanisms to increase their packaging efficiency without sacrificing the structure's capability, weight, precision or robustness. In this work, the design of a lightweight robust controllable hinge capable of actuating the lateral deployment of a Synthetic Aperture Radar (SAR) antenna is presented. This work has been completed in collaboration with the Canadian Space Agency's Structures Group, located in Saint-Hubert, Quebec.;Based on an earlier concept in the field, a modified tape-spring hinge is proposed. The tape-spring hinge exploits the stored elastic energy of curved spring steel strips placed in such a way that the hinge self-deploys and self-locks into a final stiff and straight configuration. The modified hinge is composed of two tape springs, two motion guide wheels and pins, a motion control escapement mechanism and a shape memory alloy (SMA) actuator.;It was found that the reliability of the control mechanism is highly dependant on the precise machining and positioning of the escapement components onto the hinge, and on the reduction of the friction between the parts' interface. The SMA wire proved to be a reliable and compact actuating method for the escapement. Though there was some mechanical play in the hinge itself, the hinge's uncontrolled moment-rotation behaviour was found to be qualitatively comparable to other similar hinges. However, further testing is suggested to establish the repeatability of the snap-through behaviour.;This thesis covers the design, manufacturing and testing phases of a modified tape-spring hinge prototype. The proposed hinge design and working conditions are presented. The results and challenges that were faced during the manufacturing and testing phases are explained. The tape-spring hinge's deployment behaviour is analyzed and the control mechanism's functionality is discussed. Recommendations for future work are suggested to further improve the prototype's overall performance.;Keywords: deployable structures, Synthetic Aperture Radar Antenna, tape-spring hinge, deployment control, escapement mechanism