39 research outputs found
Trajectory Servoing: Image-Based Trajectory Tracking Using SLAM
This paper describes an image based visual servoing (IBVS) system for a
nonholonomic robot to achieve good trajectory following without real-time robot
pose information and without a known visual map of the environment. We call it
trajectory servoing. The critical component is a feature-based, indirect SLAM
method to provide a pool of available features with estimated depth, so that
they may be propagated forward in time to generate image feature trajectories
for visual servoing. Short and long distance experiments show the benefits of
trajectory servoing for navigating unknown areas without absolute positioning.
Trajectory servoing is shown to be more accurate than pose-based feedback when
both rely on the same underlying SLAM system
Walking-by-Logic: Signal Temporal Logic-Guided Model Predictive Control for Bipedal Locomotion Resilient to External Perturbations
This study proposes a novel planning framework based on a model predictive
control formulation that incorporates signal temporal logic (STL)
specifications for task completion guarantees and robustness quantification.
This marks the first-ever study to apply STL-guided trajectory optimization for
bipedal locomotion push recovery, where the robot experiences unexpected
disturbances. Existing recovery strategies often struggle with complex task
logic reasoning and locomotion robustness evaluation, making them susceptible
to failures caused by inappropriate recovery strategies or insufficient
robustness. To address this issue, the STL-guided framework generates optimal
and safe recovery trajectories that simultaneously satisfy the task
specification and maximize the locomotion robustness. Our framework outperforms
a state-of-the-art locomotion controller in a high-fidelity dynamic simulation,
especially in scenarios involving crossed-leg maneuvers. Furthermore, it
demonstrates versatility in tasks such as locomotion on stepping stones, where
the robot must select from a set of disjointed footholds to maneuver
successfully