Fast foot prints re-planning and motion generation during walking in physical human-humanoid interaction

Abstract-In this paper a system allowing real-time interaction between a human and a humanoid robot while walking is presented. The aim of this work is to integrate humanoid robots into collaborative working environment. Co-located realization of a task is one instance of such collaboration. To achieve such task whole-body motion generation while keeping balance is mandatory. This is obtained using a real-time pattern generator allowing on-line foot-print modification integrated in a stack of controllers. Several experiments of direct interaction between a human and a HRP-2 humanoid robot illustrates the results

ZMP based reference generation for a bipedal humanoid robot

Recent fifteen years witnessed fast improvements in the field of humanoid robotics. The human-like robot structure is more suitable to human environment with its supreme obstacle avoidance properties when compared with wheeled service robots. However, the walking control for bipedal robots is a challenging task due to their complex dynamics. Stable reference generation plays a very important role in control. Linear Inverted Pendulum Model (LIPM) and the Zero Moment Point (ZMP) criterion are applied in a number of studies for stable walking reference generation of biped walking robots. This thesis takes this main approach too. This thesis proposes a natural and continuous ZMP reference trajectory for a stable and human-like walk. Natural, human-like walking is obtained by ZMP trajectories which move forward under the sole of the support foot when the robot body is supported by a single leg. Robot center of mass trajectory is obtained from predefined ZMP reference trajectories by a Fourier series approximation method. The Gibbs phenomenon problem common with Fourier approximations of discontinuous functions is avoided by employing continuous ZMP references. Also, these ZMP reference trajectories, unlike many examples in the literature, possess pre-assigned single and double support phases, which are very useful in experimental tuning work. In this thesis, a method for generating a stepping sequence of finite number of steps is proposed too. The ZMP based reference generation strategy is applied on the full body humanoid robot SURALP designed at Sabanci University. Experimental results indicate that the proposed reference trajectory generation technique is successful

Optimisation numérique pour la robotique et exécution de trajectoires référencées capteurs

Le travail présenté dans cette thèse est divisé en deux parties. Dans la première partie, un modèle pour la représentation unifiée de problèmes d'optimisation numérique est proposé. Ce modèle permet de définir un problème d'optimisation indépendamment de la stratégie utilisée pour le résoudre. Cette représentation unifiée est particulièrement appréciable en robotique où une solution analytique des problèmes est rarement possible. La seconde partie traite de l'exécution de mouvements complexes asservis sur un robot humanoïde. Lors de la locomotion d'un tel système, les glissements des points de contact entraînent une dérive qu'il est nécessaire de corriger. Nous proposons ici un modèle permettant d'asservir une tâche de locomotion sur un capteur externe afin de compenser les erreurs d'exécution des mouvements. Un modèle est également proposé permettant de représenter des séquences de tâches de locomotion et de manipulation asservies. Enfin, une méthodologie pour le développement d'applications robotiques complexes est établie. Les stratégies proposées dans le cadre de cette thèse ont été validées sur la plate-forme expérimentale HRP-2. ABSTRACT : The presented work is divided into two parts. In the first one, an unified computer representation for numerical optimization problems is proposed. This model allows to define problems independently from the algorithm used to solve it. This unified model is particularly interesting in robotics where exact solutions are difficult to find. The second part is dealing with complex trajectory execution on humanoid robots with sensor feedback. When a biped robots walks, contact points often slip producing a drift which is necessary to compensate. We propose here a closed-loop control scheme allowing the use of sensor feedback to cancel execution errors. To finish, a method for the the development of complex robotics application is detailed. This thesis contributions have been implemented on the HRP-2 humanoid robot