23 accepted papers
We present a framework for learning a single policy capable of producing all quadruped gaits and transitions. The framework consists of a policy trained with deep reinforcement learning (DRL) to modulate the parameters of a system of abstract oscillators (i.e. Central Pattern Generator), whose outpu
Hip exoskeletons are increasing in popularity due to their effectiveness across various scenarios and their ability to adapt to different users. However, personalizing the assistance often requires lengthy tuning procedures and computationally intensive algorithms, and most existing methods do not i
We explore the use of a mobile furniture swarm that are intended to assist users with limited mobility in their daily indoor activities. We focus on the multi-robot coordination problem when a dense target pose configuration is required, such as in an apartment setting. In those cases, the convergen
Humans have many redundancies in their bodies and can make effective use of them to adapt to changes in the environment while walking. They can also vary their walking speed in a wide range. Human-like walking in simulation or by robots can be achieved through imitation learning. However, the walkin
Animals possess a remarkable ability to navigate challenging terrains, achieved through the interplay of various pathways between the brain, central pattern generators (CPGs) in the spinal cord, and musculoskeletal system. Traditional bioinspired control frameworks often rely on a singular control p
Typical legged locomotion controllers are designed or trained offline. This is in contrast to many animals, which are able to locomote at birth, and rapidly improve their locomotion skills with few real-world interactions. Such motor control is possible through oscillatory neural networks located in
For people with limited mobility, navigating in cluttered indoor environment is challenging. In this work, we propose a mobile assistive furniture suite that is designed to ease the life of people with special needs in indoor movement. To enable intelligent coordination of this system, a key compone
In this letter, we present a method for integrating central pattern generators (CPGs), i.e. systems of coupled oscillators, into the deep reinforcement learning (DRL) framework to produce robust and omnidirectional quadruped locomotion. The agent learns to directly modulate the intrinsic oscillator
In the field of quadruped locomotion, dynamic locomotion behavior, and rich integration with sensory feedback represents a significant development. In this paper, we present an efficient neural model, which includes CPG and its sensorimotor coordination, and demonstrate its implementation in a quadr…
The computational load associated with computer vision is often prohibitive, and limits the capacity for on-board image analysis in compact mobile robots. Replicating the kind of feature detection and neural processing that animals excel at remains a challenge in most biomimetic aquatic robots. Even
Even though many prototypes of 3D self-reconfiguring modular robots (SRMRs) have been developed in recent years, a demonstration involving 1'000 modules remains a challenge. This is largely due to complex mechanics needed to achieve connection, disconnection and especially actuation in such a system
Self-reconfiguration is a hard problem due to the high dimensionality of self-reconfigurable modular systems. Searchbased approaches offer complete and optimal solutions. However, naive search algorithms cannot directly solve self-reconfiguration tasks in reasonable time. In this letter, a transitio
Gaits in legged robots are often hand tuned and time based, either explicitly or through an internal clock, for instance, in the form of central pattern generators. This strategy requires trial and error to identify leg timings, which may not be suitable in challenging terrains. In this letter, we i
We present a new framework to generate human-like lower-limb trajectories in periodic and non-periodic walking. In our method, walking dynamics is encoded in 3LP, a linear simplified model composed of three pendulums to simulate falling, swing, and torso balancing dynamics. To stabilize the motion,…
In many physical human–robot interaction scenarios, for successful completion of the tasks, robots should be able to recognize the human partner's intention. One of such scenarios that is studied in this letter is the collaborative task of carrying an object by a human–humanoid pair in which the hum
Traditional joint-space models used to describe equations of motion for humanoid robots offer nice properties linked directly to the way these robots are built. However, from a computational point of view and convergence properties, these models are not the fastest when used in planning optimization
In robotics, controlling the stiffness of the joints that contribute to the robots' degree of freedom dictates the adaptability, versatility, and safety of the whole system. We can achieve variable stiffness or impedance in a robotic system purely by the control or by introducing new material or mec
We propose a nonlinear inverse kinematics formulation which solves for positions directly. Compared to various other popular methods that integrate velocities, this formulation can better handle fast, asymmetric, and singular-postured balancing tasks for humanoid robots. We also introduce joint posi
More and more biologically inspired robots present spines with multiples degrees of freedom to resemble their biological counterparts. The function of the spine on both animal and robot can play an important role in locomotion. If it has enough degrees of freedom to allow independent control of both
In this paper, we propose a novel architecture to estimate external forces applied to a compliantly controlled balancing robot in simulations. We use similar dynamics equations used in the controller to find mismatches in the available sensory data and associate them to an unknown external force. Th…
In this paper we present a novel whole-body compliance framework. It is based on the Multi Spring Model, a set of virtual springs interconnecting the limb extremities and the trunk as well. More specifically, six virtual springs connect the trunk of the robot to the feet and the hands and other six…
We present Lynx-robot, a quadruped, modular, compliant machine. It alternately features a directly actuated, single-joint spine design, or an actively supported, passive compliant, multi-joint spine configuration. Both spine configurations bend in the sagittal plane. This study aims at characterizin…
Although considering dynamics in the control of humanoid robots can improve tracking and compliance in agile tasks, it requires local and global states of the system, precise torque control and proper modeling. In this paper we discuss practical issues to implement inverse dynamics on a torque contr…