Control Implementation of Dynamic Locomotion on Compliant, Underactuated, Force-Controlled Legged Robots with Non-Anthropomorphic Design

The control of locomotion on legged robots traditionally involves a robot that takes a standard legged form, such as the anthropomorphic humanoid, the dog-like quadruped, or the bird-like biped. Additionally, these systems will often be actuated with position-controlled servos or series-elastic actuators that are connected through rigid links. This work investigates the control implementation of dynamic, force-controlled locomotion on a family of legged systems that significantly deviate from these classic paradigms by incorporating modern, state-of-the-art proprioceptive actuators on uniquely configured compliant legs that do not closely resemble those found in nature. The results of this work can be used to better inform how to implement controllers on legged systems without stiff, position-controlled actuators, and also provide insight on how intelligently designed mechanical features can potentially simplify the control of complex, nonlinear dynamical systems like legged robots. To this end, this work presents the approach to control for a family of non-anthropomorphic bipedal robotic systems which are developed both in simulation and with physical hardware. The first is the Non-Anthropomorphic Biped, Version 1 (NABi-1) that features position-controlled joints along with a compliant foot element on a minimally actuated leg, and is controlled using simple open-loop trajectories based on the Zero Moment Point. The second system is the second version of the non-anthropomorphic biped (NABi-2) which utilizes the proprioceptive Back-drivable Electromagnetic Actuator for Robotics (BEAR) modules for actuation and fully realizes feedback-based force controlled locomotion. These systems are used to highlight both the strengths and weaknesses of utilizing proprioceptive actuation in systems, and suggest the tradeoffs that are made when using force control for dynamic locomotion. These systems also present case studies for different approaches to system design when it comes to bipedal legged robots

Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version

Development and application of smart actuation methods for vehicle simulators

Driving simulators are complex virtual reality systems that integrate visual displays, sound rendering systems, motion platforms, and human-machine-interface devices. They are used in different research areas and consequently, different studies are conducted using these systems, in conditions that would not be safe to be carried out in the real world. However, driving simulators are very expensive research tools. When building such a system, a compromise usually has to be made. Although a driving simulator cannot reproduce 1:1 real life situations or sensations because of its limitations, researchers still need to use such a device for training and research purposes, due to the realistic driving experience it has to offer to its driver. This work focuses on developing a three-degrees of freedom Essential Function Driving Simulator that integrates cost and design constraints, the human perception of motion and real vehicle motion achieved through simulated vehicle models, and the classical motion cueing strategy. The goal is, on the first hand, to immerse the driver to a certain extend into the simulation environment by using this virtual reality device and, on the second hand, to investigate the degree of realism of such a solution. Different actuation solutions are modelled and discussed in this research, with respect to the available workspace, singularity configurations, the system’s behaviour and the maximum forces needed in the frame of the overall cost constraints. A solution was chosen following kinematical and dynamical analyses, as a trade off solution among the above mentioned constraints. The human body finds itself in continuous movement and interaction with the environment. Motion is sensed by the human being through the vestibular system and the skin. The human motion perception mechanisms are mathematically modelled and studied, in order to apply their characteristics in the three-degrees of freedom driving simulator. Due to the limited workspace and degrees of freedom of the discussed simulator, the motion of the simulated vehicle cannot be identically reproduced by the motion system. Thus, special algorithms are designed to transform the motion of the vehicle model in achievable positions for the three actuators, and additionally, to render correct motion cues. The influence of the three variable parameters on the overall subjective degree of freedom is investigated using an optimisation method. The studied parameters are: motion, optical flow and haptic response, introduced by using a lane departure warning assistance system. It is shown in this research that the influence of motion cues on the subjective degree of realism rated by the drivers is of 84%. The vibrations in the steering wheel improve the realism of the simulation and have a 15% impact. The participants of these experiments could easily adapt to the provided assistance system and their immersion in the simulated environment was significantly influenced by the activation of the lane departure warning option. It has also been shown that drivers rated the motion and the accelerations felt in the simulator with 70.41%, compared to the experience of driving a real vehicle. These results are interpreted in this research by putting the emphasis on the fact that irrespective of the DOF of the actuation mechanism, a motion driving simulator should provide correct motion cues. The development of the vehicle models and of the motion cueing algorithms should be approached, so that the system provides motion as similar as possible to the real vehicle, as it is further discussed here.Entwicklung und Anwendung von intelligenten Ansteuerungsmethoden für Fahrzeugsimulatoren Fahrsimulatoren sind Virtual-Reality Systeme, die aus geeigneten Mensch-Maschinen-Schnittstellen, optische und akustische Wiedergabe und, wenn das Bedarf besteht, aus einen Bewegungsapparat bestehen. Sie werden in unterschiedlichen Forschungsfeldern verwendet um verschiedene Studien durchzuführen. Unter anderem können dadurch Manöverstudien durchgeführt werden, die in realen Fahrsituationen zu gefährlich für den Fahrer wären. Der Bau komplexer und hochauflösender Fahrsimulationen ist jedoch sehr Kostenintensiv. Obwohl ein Fahrsimulator die in realen Fahrsituationen empfundenen Fahrgefühle nicht originalgetreu wiedergegeben kann, durch den begrenzten Arbeitsraum, eignet sich ein solches Gerät zu Lehr- und Forschungszwecken. Diese Arbeit befasst sich mit der Entwickelung eines kostengünstigen Fahrsimulators mit drei Freiheitsgraden, der durch eine geeignete Motion-Cueing Strategie dem Fahrer ein ausreichendes Fahrgefühl widergibt. Es werden verschiedene Aktuierungslösungen in Bezug auf den begrenzten Arbeitsraum, singulären Stellungen, des maximalen Kraftbedarfs modelliert, verglichen und diskutiert. Es wurde eine Kompromisslösung gefunden basierend auf der kinematischen und dynamischen Analyse, die diese Begrenzungen berücksichtigt. Der menschliche Körper befindet sich in einer kontinuierlichen Bewegung und interagiert dabei mit der Umgebung. Die Bewegung wird durch das Vestibularorgan und durch die Haut wahrgenommen. Die menschliche Wahrnehmung wird durch ein geeignetes mathematisches Modell widergegeben. Der Bewegungsablauf des Fahrsimulators wurde unter Berücksichtigung der menschlichen Wahrnehmung ausgelegt und untersucht. Wegen dem begrenztem Arbeitsraum und der geringen Anzahl von Systemfreiheitsgraden kann der Simulator die reelle Fahrdynamik nicht im vollen Umfang an die Testperson weitergeben. Deshalb werden angepasste Algorithmen entwickelt um den Bewegungsablauf beschränkt durch drei Aktuatoren in einem akzeptablem umfang widerzugeben. Der Einfluss der drei Aktuatorparameter auf den Bewegungsablauf wird durch geeignete Optimierungsmethoden untersucht. Die Größen die anschließend durch das Fahrsimulator Setup untersucht werden sind unter anderem der Bewegungsablauf, die optische Darstellung und die haptische Wiedergabe. Die Wichtigkeit der empfundenen Fahrbewegung wurde durch die Probanden, im Vergleich zu einem statischen Fahrsimulator, mit 84% bewertet. Die Vibrationen im Lenkrad erhöhen das Realitätsempfinden um 15%. Die Testpersonen konnten sich schnell an die aktuierten Fahrsimulation anpassen und auch Assistenzsysteme wie Spurhalteassistent benutzen. Es wurde gezeigt, dass die im Fahrsimulator gefühlten Beschleunigungen zu ca. 70% an die im realen Fahrbetrieb empfundenen Beschleunigungen herankommen. Es hat sich gezeigt, dass der Immersionsgrad vor allem vom verwendeten Fahrzeugmodellen und den Motion-Cueing Algorithmus abhängig ist

Multibody dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat Politècnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version

MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics

El libro de actas recoge las aportaciones de los autores a través de los correspondientes artículos a la Dinámica de Sistemas Multicuerpo y la Mecatrónica (Musme). Estas disciplinas se han convertido en una importante herramienta para diseñar máquinas, analizar prototipos virtuales y realizar análisis CAD sobre complejos sistemas mecánicos articulados multicuerpo. La dinámica de sistemas multicuerpo comprende un gran número de aspectos que incluyen la mecánica, dinámica estructural, matemáticas aplicadas, métodos de control, ciencia de los ordenadores y mecatrónica. Los artículos recogidos en el libro de actas están relacionados con alguno de los siguientes tópicos del congreso: Análisis y síntesis de mecanismos ; Diseño de algoritmos para sistemas mecatrónicos ; Procedimientos de simulación y resultados ; Prototipos y rendimiento ; Robots y micromáquinas ; Validaciones experimentales ; Teoría de simulación mecatrónica ; Sistemas mecatrónicos ; Control de sistemas mecatrónicosUniversitat Politècnica de València (2011). MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/13224Archivo delegad

Proceedings of the NASA Conference on Space Telerobotics, volume 4

Papers presented at the NASA Conference on Space Telerobotics are compiled. The theme of the conference was man-machine collaboration in space. The conference provided a forum for researchers and engineers to exchange ideas on the research and development required for the application of telerobotic technology to the space systems planned for the 1990's and beyond. Volume 4 contains papers related to the following subject areas: manipulator control; telemanipulation; flight experiments (systems and simulators); sensor-based planning; robot kinematics, dynamics, and control; robot task planning and assembly; and research activities at the NASA Langley Research Center

Proceedings of the NASA Conference on Space Telerobotics, volume 1

The theme of the Conference was man-machine collaboration in space. Topics addressed include: redundant manipulators; man-machine systems; telerobot architecture; remote sensing and planning; navigation; neural networks; fundamental AI research; and reasoning under uncertainty