Humanoid realistic simulator: the servomotor joint modeling

This paper presents a humanoid servomotor model that can be used in simulations. Once simulation is a tool that reduces the software production time, it was developed a realistic simulator that own the humanoid features. Based on a real platform, the simulator is validated when compared with the reality

Proposal of a new real-time cooperative challenge in mobile robotics

In this paper it is presented a new robot competition that is going to be included in Robotica 2011, the main Robotics Portuguese Competition. The robot competition takes place in an emulated factory plant, where Automatic Guided Vehicles (AGVs) must cooperate to perform tasks. To accomplish their goals the AGVs must deal with localization, navigation, scheduling and cooperation problems, that must be solved autonomously. One option of prototyping the AGVs is the use of the Lego Mindstorms NXT technology. The presented example can play an important role in education due to the inherent multi-disciplinary concepts that are involved, motivating students to technological areas. It also plays an important role in research and development, because it is expected that the outcomes that will emerge here, will later be transfered to other application areas, such as service robots and manufacturing

Inverted pendulum virtual control laboratory

This paper describes a tool for interactive learning that can be used to improve control systems design. The developed system is ready to use and allows testing different control methods. It can be used by students for problem solving and individual learning. The virtual control laboratory was implemented as a teaching aid during lectures on control systems. As there is no need to do any special programming or debugging, the students can focus on the control items. Classical control methods such as PID and State-Space approaches are available and gains can be tuned. A friendly appearance based on openGL 3D shows a simulation of the real word: A cart with an inverted pendulum is "bumped" with a force. The dynamic equations of motion for the control system are linearized assuming that the pendulum does not move more than a few degrees away from the vertical allowing to apply linear control methods. Although, the simulated system is realistic and based on a Dynamics Engine

2D cloud template matching - a comparison between iterative closest point and perfect match

Self-localization of mobile robots in the environment is one of the most fundamental problems in the robotics field. It is a complex and challenging problem due to the high requirements of autonomous mobile vehicles, particularly with regard to algorithms accuracy, robustness and computational efficiency. In this paper we present the comparison of two of the most used map-matching algorithm, which are the Iterative Closest Point and the Perfect Match. This category of algorithms are normally applied in localization based on natural landmarks. They were compared using an extensive collection of metrics, such as accuracy, computational efficiency, convergence speed, maximum admissible initialization error and robustness to outliers in the robots sensors data. The test results were performed in both simulated and real world environments.info:eu-repo/semantics/publishedVersio

Humanoid gait optimization resorting to an improved simulation model

The simulation of a robot with a high number of joints can easily become unstable. Numerical errors on the first joint of the chain are propagated to the other joints. This is a very common problem in humanoid robots. A way to plan the gait for those robots is using simulation and optimization techniques. This paper addresses a new approach to optimize gait parameter sets using an Adaptive Simulated Annealing optimization algorithm combined with a new joint model that reduces its instability. The new model and the optimization are implemented in SimTwo (a developed physical robot simulator that is capable of simulating user defined robots in a three-dimensional space since it includes a physical model based on rigid body dynamics) and results are shown that validate the approach

Humanoid robot simulation with a joint trajectory optimized controller

This paper describes a joint trajectory optimized controller for a humanoid robot simulator following the real robot characteristics. As simulation is a powerful tool for speeding up the control software development, the proposed accurate simulator allows to fulfil this goal. The simulator, based on the Open Dynamics Engine and GLScene graphics library, provides instant visual feedback. The proposed simulator, with realistic dynamics, allows to design and test behaviours and control strategies without access to the real hardware in order to carry out research on robot control without damaging the real robot in the early stages of the development. The joints controller techniques, such as acceleration, speed and energy consumption minimization are discussed and experimental results are presented in order to validate the proposed simulator

Robust mobile robot localization based on security laser scanner

This paper addresses the development of a new localization system based on a security laser presented on most AGVs for safety reasons. An enhanced artificial beacons detection algorithm is applied with a combination of a Kalman filter and an outliers rejection method in order to increase the robustness and precision of the system. This new robust approach allows to implement such system in current AGVs. Real results in industrial environment validate the proposed methodology.The work presented in this paper, being part of the Project "NORTE-07-0124-FEDER-000060" is financed by the North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF), and by national funds, through the Portuguese funding agency, Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

Humanoid robot simulator: a realistic dynamics approach

This paper describes a humanoid robot simulator with realistic dynamics. As simulation is a powerful tool for speeding up the control software development, the suggested accurate simulator allows to accomplish this goal. The simulator, based on the Open Dynamics Engine and GLScene graphics library, provides instant visual feedback and allows the user to test any control strategy without damaging the real robot in the early stages of the development. The proposed simulator also captures some characteristics of the environment that are important and allows to test controllers without access to the real hardware. Experimental results are shown that validate this approach

A passive system approach to increase the energy efficiency in walk movements based in a realistic simulation environment

This paper presents a passive system that increases the walk energy efficiency of a Humanoid robot. A passive system is applied to the simulated robot allowing the energy consumption to be reduced. The optimal parameters for the passive system depend on the joint and gait trajectories. Final results prove the benefits of the presented system apply. It was optimized thanks to a realistic simulator where the humanoid robot was modeled. The model was validated against a real robot