Mobility Strategy of Multi-Limbed Climbing Robots for Asteroid Exploration

Mobility on asteroids by multi-limbed climbing robots is expected to achieve our exploration goals in such challenging environments. We propose a mobility strategy to improve the locomotion safety of climbing robots in such harsh environments that picture extremely low gravity and highly uneven terrain. Our method plans the gait by decoupling the base and limbs' movements and adjusting the main body pose to avoid ground collisions. The proposed approach includes a motion planning that reduces the reactions generated by the robot's movement by optimizing the swinging trajectory and distributing the momentum. Lower motion reactions decrease the pulling forces on the grippers, avoiding the slippage and flotation of the robot. Dynamic simulations and experiments demonstrate that the proposed method could improve the robot's mobility on the surface of asteroids.Comment: Submitted version of paper accepted for presentation at the CLAWAR 2023 (26th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines

Experimental Verification of Robotic Landing and Locomotion on Asteroids

peer reviewedIn-situ explorations of asteroids and other small celestial bodies are crucial to collect surface samples, which could be the key to understanding the formation of our solar system. Studying the composition of asteroids is also important for future planetary defense and mining resources for in-situ utilization. However, the weak gravitational field poses many challenges for robotic landing and locomotion scenarios on the surface of asteroids. Legged climbing robots are expected to perform well under microgravity, as they can maintain surface attachment, preventing undesired flotation and uncontrolled bouncing. Therefore, we need to consider methods to plan and control the landing and locomotion of climbing robots on asteroids. In this study, we have performed experiments regarding the emulation of two scenarios; 1- Landing, 2- Locomotion. For both landing and locomotion scenarios, separate PD controllers have been utilized

Non-Periodic Gait Planning Based on Salient Region Detection for a Planetary Cave Exploration Robot

A limbed climbing robot can traverse uneven and steep terrain, such as Lunar/Martian caves. Towards the autonomous operation of the robot, we first present a method to detect topographically salient regions in 3D point cloud as the robot ’s graspable targets, and next, we introduce a strategy to plan a non-periodic gait for the robot from the detected discrete graspable options. The proposed gait planner is implemented and validated in our open dynamic climbing robot simulation platform assuming the 3 kg class four-limbed climbing robot testbed moving over steep and uneven Lunar terrain.International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS 2020), October 19-23, 2020, Los Angles, CA, USA（新型コロナ感染拡大に伴い、オンライン開催に変更

Analysis of Motion Control for a Quadruped Ground-Gripping Robot for Minor Body Exploration on Uneven Terrain

The exploration of minor bodies, such as asteroids and comets using robotics is a necessary step for the study of the Solar System\u27s evolutionary process. For such purpose, a multi-legged ground-gripping robot was proposed to perform precise locomotion towards specific places of interest. Moreover, stable locomotion is expected, since this robot has grippers capable of grasping the rocky and uneven terrain of the minor bodies, maintaining the attachment to the ground and preventing the flotation of the robot on the microgravity environment. Decreasing the forces induced on the grippers is essential to keep the stable locomotion in such environments and, in this paper, a gait control method is proposed to reduce accelerations and motion reactions on the robot, avoiding high reaction forces on the contact points with the ground. This method focuses on generating trajectories to be traveled by parts of the robot. A numerical simulation was developed to investigate the effectiveness of the proposed method in decreasing reactions on the robot during the motion of the robot on uneven terrains by comparing different trajectories\u27 parameters.International Symposium on Space Technology and Science (32nd ISTS), June 15-21, 2019, Fukui, Japa

Analysis of Motion Control for a Quadruped Ground-Gripping Robot for Minor Body Exploration on Uneven Terrain

The exploration of minor bodies, such as asteroids and comets using robotics is a necessary step for the study of the Solar System's evolutionary process. For such purpose, a multi-legged ground-gripping robot was proposed to perform precise locomotion towards specific places of interest. Moreover, stable locomotion is expected, since this robot has grippers capable of grasping the rocky and uneven terrain of the minor bodies, maintaining the attachment to the ground and preventing the flotation of the robot on the microgravity environment. Decreasing the forces induced on the grippers is essential to keep the stable locomotion in such environments and, in this paper, a gait control method is proposed to reduce accelerations and motion reactions on the robot, avoiding high reaction forces on the contact points with the ground. This method focuses on generating trajectories to be traveled by parts of the robot. A numerical simulation was developed to investigate the effectiveness of the proposed method in decreasing reactions on the robot during the motion of the robot on uneven terrains by comparing different trajectories' parameters.International Symposium on Space Technology and Science (32nd ISTS), June 15-21, 2019, Fukui, Japa

Synergetic Cooperation Between Robots and Humans

peer reviewedMobility on asteroids by multi-limbed climbing robots is expected to achieve our exploration goals in such challenging environments. We propose a mobility strategy to improve the locomotion safety of climbing robots in such harsh environments that picture extremely low gravity and highly uneven terrain. Our method plans the gait by decoupling the base and limbs’ movements and adjusting the main body pose to avoid ground collisions. The proposed approach includes a motion planning that reduces the reactions generated by the robot’s movement by optimizing the swinging trajectory and distributing the momentum. Lower motion reactions decrease the pulling forces on the grippers, avoiding the slippage and flotation of the robot. Dynamic simulations and experiments demonstrate that the proposed method could improve the robot’s mobility on the surface of asteroids

Pasireotide treatment does not modify hyperglycemic and corticosterone acute restraint stress responses in rats.

Pasireotide is a new-generation somatostatin analog that acts through binding to multiple somatostatin receptor subtypes. Studies have shown that pasireotide induces hyperglycemia, reduces glucocorticoid secretion, alters neurotransmission, and potentially affects stress responses typically manifested as hyperglycemia and increased corticosterone secretion. This study specifically aimed to evaluate whether pasireotide treatment modifies glucose and costicosterone secretion in response to acute restraint stress. Male Holtzman rats of 150-200 g were treated with pasireotide (10 µg/kg/day) twice-daily for two weeks or vehicle for the same period. Blood samples were collected at baseline and after 5, 10, 30, and 60 min of restraint stress. The three experimental groups comprised of vehicle + restraint (VEHR), pasireotide + restraint (PASR), and pasireotide + saline (PASNR). Following pasireotide treatment, no significant differences in baseline glucose and corticosterone levels were observed among the three groups. During restraint, hyperglycemia was observed at 10 min (p \u3c .01 for both comparisons), peaked at 30 min (p \u3c .01 for both comparisons) and showed higher 60 min areas under glucose curves in the VEHR and PASR stressed groups when compared to the non-stressed PASNR group (p \u3c .05 for both comparisons). Restraint also increased corticosterone secretion in the VEHR and PASR stressed groups at 5 min (p \u3c .01 for both comparisons), and peaked at 30 min (p \u3c .01 for both comparisons) with corresponding higher 60 min areas under corticosterone curves when compared to the non-stressed PASNR group (p \u3c .01 for both comparisons). In conclusion, pasireotide treatment does not modify hyperglycemic- and corticosterone-restraint stress responses, thus preserving acute stress regulation