Tim Laue

SimRobot – a general physical robot simulator and its application in robocup

This paper describes SimRobot, a robot simulator which is able to simulate arbitrary user-defined robots in three-dimensional space. It includes a physical model which is based on rigid body dynamics. To allow an extensive flexibility in building accurate models, a variety of different generic bodies, sensors and actuators has been implemented. Furthermore, the simulator follows an user-oriented approach by including several mechanisms for visualization, direct actuator manipulation, and interaction with the simulated world. To demonstrate the general approach, this paper presents multiple examples of different robots which have been simulated so far.

SSL-vision: the shared vision system for the robocup small size league

The current RoboCup Small Size League rules allow every team to set up their own global vision system as a primary sensor. This option, which is used by all participating teams, bears several organizational limitations and thus impairs the league’s progress. Additionally, most teams have converged on very similar solutions, and have produced only few significant research results to this global vision problem over the last years. Hence the responsible committees decided to migrate to a shared vision system (including also sharing the vision hardware) for all teams by 2010. This system – named SSL-Vision – is currently developed by volunteers from participating teams. In this paper, we describe the current state of SSL-Vision, i.e. its software architecture as well as the approaches used for image processing and camera calibration, together with the intended process for its introduction and its use beyond the scope of the Small Size League.

Navigating a smart wheelchair with a brain-computer interface interpreting steady-state visual evoked potentials

In order to allow severely disabled people who cannot move their arms and legs to steer an automated wheelchair, this work proposes the combination of a non-invasive EEG-based human-robot interface and an autonomous navigation system that safely executes the issued commands. The robust classification of steady-state visual evoked potentials in brain activity allows for the seamless projection of qualitative directional navigation commands onto a frequently updated route graph representation of the environment. The deduced metrical target locations are navigated to by the application of an extended version of the well-established nearness diagram navigation method. The applicability of the system proposed is demonstrated by a real-world pilot study in which eight out of nine untrained subjects successfully navigated an automated wheelchair, requiring only some ten minutes of preparation.

Kick it with elasticity: Safety and performance in human-robot soccer

The RoboCup community has one definite goal [H. Kitano, M. Asada, RoboCup humanoid challenge: Thats one small step for a robot, one giant leap for mankind, in: IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, IROS1998, Victoria, pp. 419-424, 1998]: winning against the human world soccer champion team by the year 2050. This implies real tackles and fouls between humans and robots, rising safety concerns for the robots and even more important for the human players. Nowadays, similar questions are discussed in the field of physical human-robot interaction (pHRI), but mainly in the context of industrial and service robotics applications. The first part of our paper is an attempt for a pHRI view on human-robot soccer. We take scenes from real soccer matches and discuss what could have happened if one of the teams consisted of robots instead of humans. The most important result is that elastic joints are needed to reduce the impact during collisions. The second and third part consider conversely, how the robot can handle the impact of kicking the ball and how it can reach the velocity of human-level soccer. Again joint elasticity is the key point. Overall, the paper analyzes a vision far ahead. However, all our conclusions are based on concrete simulations, experiments, derivations, or findings from sports science, forensics, and pHRI.

Controlling an automated wheelchair via joystick/head-joystick supported by smart driving assistance

With this work, we encourage the application of smart driving assistance algorithms to support the operator of an automated wheelchair in complex navigational situations. On the basis of an empirical study in which eight untrained subjects performed a given course using a conventional joystick and a proportional head-joystick respectively, we are able to prove benefits resulting from the application of a newly developed driving assistance module. Altering the translational and rotational velocities in situations where an obstacle blocks the user-commanded way, the driving assistance module significantly improves driver-performance by preventing all collisions along the way.

A behavior architecture for autonomous mobile robots based on potential fields

This paper describes a behavior-based architecture which integrates existing potential field approaches concerning motion planning as well as the evaluation and selection of actions into a single architecture. This combination allows, together with the concept of competing behaviors, the specification of more complex behaviors than the usual approach which is focusing on behavior superposition and is mostly dependent on additional external mechanisms. The architecture and all methods presented in this paper have been implemented and applied to different robots.

Particle-Filter-Based self-localization using landmarks and directed lines

The paper presents the self-localization approach used by the World Champion in the Sony Four-Legged Robot League 2004. The method is based on a particle filter that makes use of different features from the environment (beacons, goals, field lines, field wall) that provide different kinds of localization information and that are recognized with different frequencies. In addition, it is discussed how the vision system acquires these features, especially, how the orientation of field lines is determined at low computational costs.

Kicking a ball - modeling complex dynamic motions for humanoid robots

Complex motions like kicking a ball into the goal are becoming more important in RoboCup leagues such as the Standard Platform League. Thus, there is a need for motion sequences that can be parameterized and changed dynamically. This paper presents a motion engine that translates motions into joint angles by using trajectories. These motions are defined as a set of Bezier curves that can be changed online to allow adjusting, for example, a kicking motion precisely to the actual position of the ball. During the execution, motions are stabilized by the combination of center of mass balancing and a gyro feedback-based closed-loop PID controller.

Entropy-based active vision for a humanoid soccer robot

In this paper, we show how the estimation of a robots world model can be improved by actively sensing the environment through considering the current world state estimate through minimizing the entropy of an underlying particle distribution. Being originally computationally expensive, this approach is optimized to become executable in real-time on a robot with limited resources. We demonstrate the approach on a humanoid robot, performing self-localization and ball tracking on a RoboCup soccer field.

Foul 2050: thoughts on physical interaction in human-robot soccer

The RoboCup community has one definite goal: winning against the human world soccer champion team by the year 2050. This implies real tackles and fouls between humans and robots and rises safety concerns for the robots and even more important for the human players. Nowadays, similar questions are discussed in the field of physical human- robot interaction (pHRI), but mainly in the context of industrial and service robotics applications. Our paper is an attempt for a pHRI view on human-robot soccer. Technically, this will be years ahead, but still we believe it is enlighting to analyze the RoboCup vision from the perspective of pHRI. We take scenes from the 2006 FIFA World Cup as examples and discuss what could have happened if one of the teams consisted of robots instead of humans.