Orientation Control System: Enhancing Aerial Maneuvers for Quadruped Robots

Abstract

For legged robots, aerial motions are the only option to overpass obstacles that cannot be circumvented with standard locomotion gaits. In these cases, the robot must perform a leap to either jump onto the obstacle or fly over it. However, these movements represent a challenge, because, during the flight phase, the Center of Mass (CoM) cannot be controlled, and there is limited controllability over the orientation of the robot. This paper focuses on the latter issue and proposes an Orientation Control System (OCS), consisting of two rotating and actuated masses (flywheels or reaction wheels), to gain control authority on the orientation of the robot. Due to the conservation of angular momentum, the rotational velocity if the robot can be adjusted to steer the robot’s orientation, even when the robot has no contact with the ground. The axes of rotation of the flywheels are designed to be incident, leading to a compact orientation control system that is capable of controlling both roll and pitch angles, considering the different moments of inertia in the two directions. The concept was tested by means of simulations on the robot Solo12.

Hierarchical Vision Navigation System for Quadruped Robots with Foothold Adaptation Learning

“…The navigation policy of our proposed system processes depth observation using a 2-D CNN to obtain l depth . The layer configurations include input channel number, output channel number, kernel size, and stride of (1,32,8,4), (32,64,4,2), and (64, 64, 3, 1), with a zero-padding of (2, 2, 2, 2) and (1, 1, 1, 1) for the first two layers. Task observation is processed using a 2-layer MLP with (3, 256) and (256, 256), resulting in l task .…”

“…The results also demonstrate the difficulty of navigating a robot without consideration of the robot dynamics. 1 We implement the baseline methods in the same experimental environments for comparison.…”

“…Recently, legged robots have demonstrated agile locomotion advantages over wheeled robots, especially when walking in various challenging scenes with obstacles such as thresholds, steps, furniture, and pedestrians. Quadruped robots can perform various motions [1] and undertake various dangerous and dirty tasks such as disaster relief and mine exploration [2]. Thus safe and efficient navigation is promising in the study of quadruped robots.…”