15 accepted papers
Accurate full-body motion prediction is essential for the safe, autonomous navigation of legged robots, enabling critical capabilities like limb-level collision checking in cluttered environments. Simplified kinematic models often fail to capture the complex, closed-loop dynamics of the robot and it…
This paper presents a Model Predictive Control (MPC) formulation for bipedal footstep planning based on the Linear Inverted Pendulum (LIP) model, ensuring recursive feasibility when navigating restricted regions. The proposed approach incorporates capturability and introduces a new constraint that f
Humanoid robots are expected to navigate in changing environments and perform a variety of tasks. Frequently, these tasks require the robot to make decisions online regarding the speed and precision of following a reference path. For example, a robot may want to decide to temporarily deviate from it…
This letter presents a sequential Model Predictive Control (MPC) approach to reactive motion planning for bipedal robots in highly cluttered environments with moving obstacles. The approach relies on a directed convex decomposition of the free space, which provides a safe corridor in the form of an
In this letter, we consider the problem of adapting a dynamically walking bipedal robot to follow a leading co-worker based on physical interaction. Our approach relies on switching among a family of Dynamic Movement Primitives (DMPs) as governed by a supervisor. We train the supervisor to orchestra
This paper presents an adaptive control scheme for robotic systems that operate in the face of-potentially large-structured uncertainty. The proposed adaptive controller employs an on-line supervisor that utilizes logic-based switching among a finite set of controllers to identify uncertain paramete…
Complex robot motions are frequently generated by composing simpler primitive movements. We use this approach to formulate robot motion plans as sequences of primitives to be executed one after the other. When dealing with dynamical movement primitives, besides accomplishing the high-level objective…
This paper presents a method to achieve online gait adaptation of a dynamically walking biped when collaborating with an external agent-either a human or a robot-acting as a leader. Adaptation occurs without any explicit information on the leader's intended motion; only implicit information is used…
This paper presents a method for navigating 3D dynamically walking bipedal robots amidst obstacles. Our framework relies on composing gait primitives corresponding to limit-cycle locomotion behaviors and it produces nominal motion plans that are compatible with the system's dynamics and can be track…
This paper presents a control method for steering three dimensional (3D) dynamically walking bipeds that are engaged in cooperative tasks such as object transportation. Towards achieving safe interaction with a leading human (or robot) collaborator, the walking biped is required to exhibit complianc…
This paper approaches from an optimal control perspective the problem of fixed-time detection of mobile radioactive sources in transit by means of a collection of mobile sensors. Under simplifying assumptions on the geometry of the source, sensors, and surrounding environment, and with knowledge of…
This paper presents a method for integrating a cooperative manipulation task in the design of dynamic walking motions for an underactuated bipedal robot. Applications that involve physical interaction between a walking biped and a leading human (or robot) collaborator, require that the biped exhibit…
This paper investigates the ability of dynamically walking bipeds to adapt their motion to persistent exogenous forcing. Applications that involve physical interactions between a bipedal robot and other robots (or humans), require that the robot adjust its stepping pattern in response to externally…
This paper examines the problem of transitioning between gaits using a sagittal-plane reduced-order model of quadrupedal running, which has compliant elements in its torso and legs. First, periodic motions that correspond to pronking and two variations of bounding are generated. Analysis of the tors…
Inspired by biological systems, compliant elements are introduced in the driving train of legged robots with the purpose of recycling energy. This paper presents the design and control concept of the monopedal robot SPEAR, driven by a novel implementation of a Switchable Parallel Elastic Actuator (S…