A Modular Reconfigurable Robot for Future Autonomous Extraterrestrial Missions
Alexey M. Romanov, Vladimir D. Yashunskiy, Wei‐Yu Chiu
Abstract
This study proposes a heterogeneous modular reconfigurable robot called SABER that is suitable for future autonomous extraterrestrial missions. SABER is a Step, Assembler, Bridge, Explorer Robot comprising a platform and a reconfigurable rail; it can work in three different configurations: monowheel, rail trolley, and manipulator. The monowheel configuration provides locomotion with a speed up to 10 km/h. The rail trolley configuration allows the robot to overcome gaps larger than its wheel diameter, climb steps as large as the wheel radius, and pass through passages smaller than the wheel diameter. The manipulator configuration enables the robot to manipulate objects using two robotic arms with changeable tools. This design allows several SABERs to work cooperatively, extending capabilities of their mechanics or enlarging the working area. As such, SABERs can address various tasks relevant to extraterrestrial missions, including exploration, outpost building and equipment maintenance. The key feature of the SABER is the mechanical transmission that allows its platform to move at a high speed along the rail made from the manipulators of the robot. To provide robust operation of the transmission, a new jamming safety diagram ensuring collision free was developed to determine controller precision requirements. Finally, a new positioning controller meeting those requirements was introduced and implemented as FPGA firmware compatible with a wide range of low cost integrated circuits. Robot performance in terms of the speed, acceleration, oscillation, and gap/step handling was numerically analyzed, showing that SABER is comparable with or better than existing autonomous mobile robots and modular reconfigurable robots.