Implementation and Testing of a Sensor and Control Scheme for a Reconfigurable Smart Wheel

• Main Author: Tsakyridis, Georgios
• Format: Others
• Language: English
• Published: 2012
• Subjects: Technology; Rimres; Wheel; Teknik
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-47239

The DFKI Robotics Innovation Center and the ZARM (Center of Applied Space Technology and Microgravity), developed within a joint program, a Reconfigurable Integrated Multi Robot Exploration System, RIMRES, for demonstrating key technologies required for performing exploratory tasks on the Moon surface and other hostile planetary terrains autonomously. Maximizing eciency and performance while demonstrating key technologies required in the area of autonomy, navigation and locomotion by combining heterogeneous robots into one overall system are the major objectives of the project. For this purposes, two dierent robotic vehicles, connected tidily by unique mechanical and electrical interfaces, can act as independent units if necessary or as one single system. This thesis was written in close collaboration with the German Aerospace Centre (DLR) at the Institute of Space Systems in Bremen and deals with the implementation and testing of a sensor and control scheme for a reconfigurable smart wheel developed within the RIMRES project. Having as starting point the wheel concept design used for the ExoMars mission, where flexible metal spokes were used to enlarge the wheels ground contact area, DLR undertake the development of a smart reconfigurable wheel to incorporate with the RIMRES project. The wheel, equipped with a sensor and control scheme to monitor soil characteristics and parameters, while actively adapt its stiness accordingly. Equivalent to the inflation of a rubber tyre, by increasing the stiness of the wheel the rolling resistance can be minimized when running on hard ground, while decreasing the wheels stiness will maximize the tractive force when running over soft ground. The thesis work focus on the development of such a sensor-control platform. By carefully studying previous approaches and considering several factors and limitations, an all new system is proposed in order to achieve the complex problem of soil characterization and active control of the wheel by meanings of simplicity and high eciency. The outcome solution is subsequently tested to prove the premise. Previous mission, NASA Pathfinder mission, have extendedly proof that surface characterization by sensor equipped wheels is a feasible and pragmatic scenario. Working as "mini-field geologists" space exploration mobile vehicles are a major achievement towards mapping extra-terrestrial planets. Harsh environment conditions, terrain anomalies and uncertainties together with the lost of MER ( Mars Exploration Rovers) Spirit rover failure enhanced the needs for building sensor equipped wheels for soft obstacle detection at a higher mobility performance on soft grounds. DLR, a keystone nowadays in the Aerospace sector,counting several years of experience and important achievement such is the ExoMars rover, a rover with primary objective to search for sign of past and present life on Mars, engaged in constructing such a complex locomotive system. === <p>Validerat; 20121119 (global_studentproject_submitter)</p>