To simplify the development of new trajectories for a humanoid robot with many joints, the ability to check for potential collisions is crucial. More importantly, to enable online generation of general motions, such as whole-body-motion, collision avoidance must be employed, which is usually more challenging. In this paper, a model-based and efficient on-line distance calculation between links of the robot is proposed. To avoid collisions the results are projected into the nullspace term of the inverse-kinematics which is based on the redundancy resolution framework of LIÉGEOIS. Additionally, a novel method to reduce the vertical angular momentum for a walking biped robot which uses the arm motion is proposed. It reduces the vertical angular momentum of the walking robot especially for larger steps. Since the method also works in the null-space, it can easily be combined with the proposed collision avoidance scheme. Finally, results for the proposed methods from simulations and experiments with the robot Lola are shown.

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We present a new approach to autonomous navigation for humanoid robots in previously unknown environments. Our method uses only on-board cameras and does not rely on color coding, textured surfaces or predefined object models. We propose using a reactive approach towards navigation that does not require building an explicit model of the environment. The basic idea of the navigation system is to check a set of precalculated feasible trajectories (called tentacles) for passability instead of searching for a path within a map. The computer vision system was combined with our real-time trajectory planning and control, enabling our robot LOLA to safely navigate in previously unknown environments.

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This paper describes the control, communication and sensor network of the humanoid robot LOLA. A brief description of the complex decentralized electronic architecture will be given. A dedicated circuit board has been developed as decentralized computation device and sensor-controller interface. A detailed description of the hardware and software capabilities of the board is given. The implementation of the real-time communication network based on Sercos-III is described. Finally, a description of the control structure of LOLA is given.