Using humanoid robots to study human behavior

Our understanding of human behavior advances as our humanoid robotics work progresses-and vice versa. This team's work focuses on trajectory formation and planning, learning from demonstration, oculomotor control and interactive behaviors. They are programming robotic behavior based on how we humans “program” behavior in-or train-each other

A Brachiating Robot Controller

We report on our empirical studies of a new controller for a two-link brachiating robot. Motivated by the pendulum-like motion of an ape\u27s brachiation, we encode this task as the output of a target dynamical system. Numerical simulations indicate that the resulting controller solves a number of brachiation problems that we term the ladder, swing-up, and rope problems. Preliminary analysis provides some explanation for this success. The proposed controller is implemented on a physical system in our laboratory. The robot achieves behaviors including swing locomotion and swing up and is capable of continuous locomotion over several rungs of a ladder. We discuss a number of formal questions whose answers will be required to gain a full understanding of the strengths and weaknesses of this approach

The Role of Reflexes Versus Central Pattern Generators

Animals execute locomotor behaviors and more with ease. They have evolved these breath-taking abilities over millions of years. Cheetahs can run, dolphins can swim and flies can fly like no artificial technology can. It is often argued that if human technology could mimic nature, then biological-like performance would follow. Unfortunately, the blind copying or mimicking of a part of nature [Ritzmann et al., 2000] does not often lead to the best design for a variety of reasons [Vogel, 1998]. Evolution works on the just good enough principle. Optimal designs are not the necessary end product of evolution. Multiple satisfactory solutions can result in similar performances. Animals do bring to our attention amazing designs, but these designs carry with them the baggage of their history. Moreover, natural design is constrained by factors that may have no relationship to human engineered designs. Animals must be able to grow over time, but still function along the way. Finally, animals are complex and their parts serve multiple functions, not simply the one we happen to examine. In short, in their daunting complexity and integrated function, understanding animal behaviors remains as intractable as their capabilities are tantalizing

A Hybrid Swing up Controller for a Two-link Brachiating Robot

In this paper, we report on a hybrid scheme for regulating the swing up behavior of a two degree of freedom brachiating robot. In this controller, a previous target dynamics controller and a mechanical energy regulator are combined. The proposed controller guarantees the boundedness of the total energy of the system. Simulations suggest that this hybrid controller achieves much better regulation of the desired swing motion than the target dynamics method by itself

Kontextsensitive Körperregulierung für redundante Roboter

In the past few decades the classical 6 degrees of freedom manipulators' dominance has been challenged by the rise of 7 degrees of freedom redundant robots. Similarly, with increased availability of humanoid robots in academic research, roboticists suddenly have access to highly dexterous platforms with multiple kinematic chains capable of undertaking multiple tasks simultaneously. The execution of lower-priority tasks, however, are often done in task/scenario specific fashion. Consequently, these systems are not scalable and slight changes in the application often implies re-engineering the entire control system and deployment which impedes the development process over time. This thesis introduces an alternative systematic method of addressing the secondary tasks and redundancy resolution called, context aware body regulation. Contexts consist of one or multiple tasks, however, unlike the conventional definitions, the tasks within a context are not rigidly defined and maintain some level of abstraction. For instance, following a particular trajectory constitutes a concrete task while performing a Cartesian motion with the end-effector represents an abstraction of the same task and is more appropriate for context formulation. Furthermore, contexts are often made up of multiple abstract tasks that collectively describe a reoccurring situation. Body regulation is an umbrella term for a collection of schemes for addressing the robots' redundancy when a particular context occurs. Context aware body regulation offers several advantages over traditional methods. Most notably among them are reusability, scalability and composability of contexts and body regulation schemes. These three fundamental concerns are realized theoretically by in-depth study and through mathematical analysis of contexts and regulation strategies; and are practically implemented by a component based software architecture that complements the theoretical aspects. The findings of the thesis are applicable to any redundant manipulator and humanoids, and allow them to be used in real world applications. Proposed methodology presents an alternative approach for the control of robots and offers a new perspective for future deployment of robotic solutions.Im Verlauf der letzten Jahrzehnte wich der Einfluss klassischer Roboterarme mit 6 Freiheitsgraden zunehmend denen neuer und vielfältigerer Manipulatoren mit 7 Gelenken. Ebenso stehen der Forschung mit den neuartigen Humanoiden inzwischen auch hoch-redundante Roboterplattformen mit mehreren kinematischen Ketten zur Verfügung. Diese überaus flexiblen und komplexen Roboter-Kinematiken ermöglichen generell das gleichzeitige Verfolgen mehrerer priorisierter Bewegungsaufgaben. Die Steuerung der weniger wichtigen Aufgaben erfolgt jedoch oft in anwendungsspezifischer Art und Weise, welche die Skalierung der Regelung zu generellen Kontexten verhindert. Selbst kleine Änderungen in der Anwendung bewirken oft schon, dass große Teile der Robotersteuerung überarbeitet werden müssen, was wiederum den gesamten Entwicklungsprozess behindert. Diese Dissertation stellt eine alternative, systematische Methode vor um die Redundanz neuer komplexer Robotersysteme zu bewältigen und vielfältige, priorisierte Bewegungsaufgaben parallel zu steuern: Die so genannte kontextsensitive Körperregulierung. Darin bestehen Kontexte aus einer oder mehreren Bewegungsaufgaben. Anders als in konventionellen Anwendungen sind die Aufgaben nicht fest definiert und beinhalten eine gewisse Abstraktion. Beispielsweise stellt das Folgen einer bestimmten Trajektorie eine sehr konkrete Bewegungsaufgabe dar, während die Ausführung einer Kartesischen Bewegung mit dem Endeffektor eine Abstraktion darstellt, die für die Kontextformulierung besser geeignet ist. Kontexte setzen sich oft aus mehreren solcher abstrakten Aufgaben zusammen und beschreiben kollektiv eine sich wiederholende Situation. Durch die Verwendung der kontextsensitiven Körperregulierung ergeben sich vielfältige Vorteile gegenüber traditionellen Methoden: Wiederverwendbarkeit, Skalierbarkeit, sowie Komponierbarkeit von Konzepten. Diese drei fundamentalen Eigenschaften werden in der vorliegenden Arbeit theoretisch mittels gründlicher mathematischer Analyse aufgezeigt und praktisch mittels einer auf Komponenten basierenden Softwarearchitektur realisiert. Die Ergebnisse dieser Dissertation lassen sich auf beliebige redundante Manipulatoren oder humanoide Roboter anwenden und befähigen diese damit zur realen Anwendung außerhalb des Labors. Die hier vorgestellte Methode zur Regelung von Robotern stellt damit eine neue Perspektive für die zukünftige Entwicklung von robotischen Lösungen dar

Spatial and Timing Regulation of Upper-Limb Movements in Rhythmic Tasks

Rhythmic movement is vital to humans and a foundation of such activities as locomotion, handwriting, and repetitive tool use. The spatiotemporal regularity characterizing such movements reflects a level of automaticity and coordination that is believed to emerge from mutually inhibitory or other pattern generating neural networks in the central nervous system. Although many studies have provided descriptions of this regularity and have illuminated the types of sensory information that influence rhythmic behavior, an understanding of how the brain uses sensory feedback to regulate rhythmic behavior on a cycle-by-cycle basis has been elusive. This thesis utilizes the model task of paddle juggling, or vertical ball bouncing, to address how three types of feedback---visual, auditory, and haptic---contribute to spatial and temporal regulation of rhythmic upper-limb movements. We use a multi-level approach in accordance with the well-known dictum of Marr and Poggio. The crux of this thesis describes a method and suite of experiments to understand how the brain uses visual, audio, and haptic feedback to regulate spatial or timing regularity, and formulate acycle-by-cycle description of this control: to wit, the nature and algorithms of sensory-feedback guided regulation. Part I motivates our interest in this problem, by discussing the biological ``hardware'' that the nervous system putatively employs in these movements, and reviewing insights from previous studies of paddle juggling that suggest how the ``hardware'' may manifest itself in these behaviors. The central experimental approach of this thesis is to train participants to perform the paddle juggling task with spatiotemporal regularity (in other words, to achieve limit-cycle behavior), and then interrogate how the brain applies regulates closed-loop performance by perturbing task feedback. In Part II, we review the development of a novel hard-real-time virtual-reality juggling simulator that enabled precise spatial and temporal feedback perturbations. We then outline the central experimental approach, in which we perturb spatial feedback of the ball at apex phase (vision), and timing feedback of collision- (audio and haptic) and apex-phase events to understand spatial and timing regulation. Part III describes two experiments that yield the main research findings of this thesis. In Experiment 1, we use a sinusoidal-perturbation-based system identification approach to determine that spatial and timing feedback are used in two dissociable and complementary control processes: spatial error correction and temporal synchronization. In Experiment 2, a combination of sinusoidal and step perturbations is used to establish that these complementary processes obey different dynamics. Namely, spatial correction is a proportional-integral process based on a one-step memory of feedback, while temporal synchronization is a proportional process that is dependent only on the most recent feedback. We close in Part IV with a discussion of how insights and approaches from this thesis can lead to improved rehabilitation approaches and understanding of the physiological basis of rhythmic movement regulation

Fruffeltin

Fruffeltin is a short 2D animated film following the journey of a goofy children’s book character trying to win back the affection of a child after being replaced by a fighting video game. The film’s core message regarding mental health awareness is illuminated through the visualization of character-driven animation, juxtaposing environments and symbolic details. The concept stems from my own personal growth trajectory and reflection upon it within the framework of animated creatures and robots. The narrative follows Fruffeltin, a children’s book character with three leaves on his head, who lives to make a young boy laugh by performing silly tricks. When the young boy’s attention is drawn to a video game instead, Fruffeltin sets out on a mission to regain his attention within the futuristic video game world. Out of his element, Fruffeltin finds himself struggling to perform his usual tricks and is further hindered by the older brother, who uses his game robot to interfere in the process. Fruffeltin has to determine whether to stay in this world and win back the boy’s attention in the face of these mounting obstacles