The sample fetch rover (SFR) is a novel surface vehicle studied for Mars sample return (MSR). The rover is designed as a multi-mission transportation system with no scientific payloads on board and the only objective ...
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The sample fetch rover (SFR) is a novel surface vehicle studied for Mars sample return (MSR). The rover is designed as a multi-mission transportation system with no scientific payloads on board and the only objective of acquiring sample tubes previously deposited on the surface and delivering them to a lander in a strict timeframe. Its mission imposes demanding requirements, such as traverse distance, timeline, mass, volume, and energy, which necessitate the development of new technologies or the augmentation of existing ones. Following the decision not to implement SFR in the MSR campaign, these technologies are becoming attractive for future rover missions to Mars and to the Moon. This paper summarizes the development of these technologies and their applicability to future use cases. The SFR mission profile and design drivers are described herein, along with the system architecture established in response to them. What follows is an overview of the key technologies studied for SFR, focusing on the most critical or innovative ones, such as locomotion, navigation, and sample tube acquisition. The summary includes the other significant aspects of the design: structure, thermal control, mechanisms, control electronics, power, avionics, and communications. For each of these, the main technological advancements and their relevance to forthcoming rover missions are discussed.
Wire arc additive manufacturing (WAAM) is a metal 3D printing technology that rapidly prototypes by depositing molten metal wire onto a substrate. Traditionally, WAAM has relied on the open-loop control with carefully...
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Wire arc additive manufacturing (WAAM) is a metal 3D printing technology that rapidly prototypes by depositing molten metal wire onto a substrate. Traditionally, WAAM has relied on the open-loop control with carefully tuned parameters, a process that can be time-consuming and often results in inconsistent performance. Although laser line scanners and other 3D scanning techniques have been used to ensure geometric fidelity, they typically provide feedback through layer-by-layer scans, leaving imperfections from arc striking and extinguishing. This paper introduces a novel approach that incorporates infrared (IR) camera thermography to achieve more consistent and reliable WAAM printing with real-time feedback. By using IR live streaming to close the loop with in-layer updates, we demonstrate how this feedback mechanism can enhance control over bead width consistency and wire stick-out length, ultimately leading to higher-quality metal 3D-printed structures. Compared with open-loop preset constant welding parameters on a triangular wall geometry, our IR-guided WAAM process achieves 49% bead width variance reduction and 95% wire stick-out length tracking improvement.
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