57 research outputs found
Impact-Aware Online Motion Planning for Fully-Actuated Bipedal Robot Walking
The ability to track a general walking path with specific timing is crucial
to the operational safety and reliability of bipedal robots for avoiding
dynamic obstacles, such as pedestrians, in complex environments. This paper
introduces an online, full-body motion planner that generates the desired
impact-aware motion for fully-actuated bipedal robotic walking. The main
novelty of the proposed planner lies in its capability of producing desired
motions in real-time that respect the discrete impact dynamics and the desired
impact timing. To derive the proposed planner, a full-order hybrid dynamic
model of fully-actuated bipedal robotic walking is presented, including both
continuous dynamics and discrete lading impacts. Next, the proposed
impact-aware online motion planner is introduced. Finally, simulation results
of a 3-D bipedal robot are provided to confirm the effectiveness of the
proposed online impact-aware planner. The online planner is capable of
generating full-body motion of one walking step within 0.6 second, which is
shorter than a typical bipedal walking step
Planning and Control Strategies for Motion and Interaction of the Humanoid Robot COMAN+
Despite the majority of robotic platforms are still confined in controlled environments such as factories, thanks to the ever-increasing level of autonomy and the progress on human-robot interaction, robots are starting to be employed for different operations, expanding their focus from uniquely industrial to more diversified scenarios.
Humanoid research seeks to obtain the versatility and dexterity of robots capable of mimicking human motion in any environment. With the aim of operating side-to-side with humans, they should be able to carry out complex tasks without posing a threat during operations.
In this regard, locomotion, physical interaction with the environment and safety are three essential skills to develop for a biped.
Concerning the higher behavioural level of a humanoid, this thesis addresses both ad-hoc movements generated for specific physical interaction tasks and cyclic movements for locomotion. While belonging to the same category and sharing some of the theoretical obstacles, these actions require different approaches: a general high-level task is composed of specific movements that depend on the environment and the nature of the task itself, while regular locomotion involves the generation of periodic trajectories of the limbs.
Separate planning and control architectures targeting these aspects of biped motion are designed and developed both from a theoretical and a practical standpoint, demonstrating their efficacy on the new humanoid robot COMAN+, built at Istituto Italiano di Tecnologia.
The problem of interaction has been tackled by mimicking the intrinsic elasticity of human muscles, integrating active compliant controllers. However, while state-of-the-art robots may be endowed with compliant architectures, not many can withstand potential system failures that could compromise the safety of a human interacting with the robot. This thesis proposes an implementation of such low-level controller that guarantees a fail-safe behaviour, removing the threat that a humanoid robot could pose if a system failure occurred
Sequential Motion Planning for Bipedal Somersault via Flywheel SLIP and Momentum Transmission with Task Space Control
In this paper, we present a sequential motion planning and control method for generating somersaults on bipedal robots. The somersault (backflip or frontflip) is considered as a coupling between an axile hopping motion and a rotational motion about the center of mass of the robot; these are encoded by a hopping Spring-loaded Inverted Pendulum (SLIP) model and the rotation of a Flywheel, respectively. We thus present the Flywheel SLIP model for generating the desired motion on the ground phase. In the flight phase, we present a momentum transmission method to adjust the orientation of the lower body based on the conservation of the centroidal momentum. The generated motion plans are realized on the full-dimensional robot via momentum-included task space control. Finally, the proposed method is implemented on a modified version of the bipedal robot Cassie in simulation wherein multiple somersault motions are generated
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