We report results from a collaborative project that investigated the deployment of humanoid robotic solutions in aircraft manufacturing for some assembly operations where access is not possible for wheeled or rail-ported robotic platforms. Recent developments in multi-contact planning and control, bipedal walking, embedded SLAM, whole-body multi-sensory task space optimization control, and contact detection and safety, suggest that humanoids could be a plausible solution for automation given the specific requirements in such large-scale manufacturing sites. The main challenge is to integrate these scientific and technological advances into two existing humanoid platforms: the position controlled HRP-4 and the torque controlled TORO. This integration effort was demonstrated in a bracket assembly operation inside a 1:1 scale A350 mock-up of the front part of the fuselage at the Airbus Saint-Nazaire site. We present and discuss the main results that have been achieved in this project and provide recommendations for future work.

This paper presents a novel multi-step closed-form walking trajectory generator based on the concept of Divergent Component of Motion (DCM) that guarantees smoothness of all resulting reference trajectories. Further, we introduce an analytical method for footstep adjustment to recover from strong disturbances. The DCM trajectory is adjusted to guarantee smoothness of control outputs. Additionally, we present a momentum-based disturbance observer that improves robustness w.r.t. strong continuous perturbations. The proposed methods are verified in simulations.

This paper presents a complete trajectory generation and control approach for achieving a robust dynamic walking gait for humanoid robots over compliant and uneven terrain. The work uses the concept of Divergent Component of Motion (DCM) for generating the center of mass (CoM) trajectory, and Cartesian polynomial trajectories for the feet. These reference trajectories are tracked by a passivity-based whole-body controller, which computes the joint torques for commanding our torque-controlled humanoid robot TORO. We provide the implementation details regarding the trajectory generation and control that help preventing discontinuities in the commanded joint torques, which facilitates precise trajectory tracking and robust locomotion. We present extensive experimental results of TORO walking over rough terrain, grass, and, to the best of our knowledge, the first report of a humanoid robot walking over a soft gym mattress.

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This letter presents an in-depth analysis of the convex properties of center-of-mass (CoM) trajectories for legged robot locomotion based on the concept of Divergent Component of Motion (DCM). In particular, we show that the union of all possible trajectories forms a bounded convex set under appropriate boundary conditions. Additionally, we describe in detail our approach of generating closed-form CoM trajectories through piecewise interpolation over a sequence of waypoints and show how to compute the CoM trajectory efficiently through equations given in a matrix form. Applying the convex properties to our trajectory-generation approach, we present an algorithm for computing convex overapproximations of the CoM waypoints. Finally, we provide an example of usage in placing waypoints that lead to feasible CoM trajectories with respect to kinematic and dynamic constraints. The approach is validated with a multi-contact scenario in simulation with the humanoid robot TORO.