Tactile and Touchless Sensors Printed on Flexible Textile Substrates for Gesture Recognition

Tesis por compendio[EN] The main objective of this thesis is the development of new sensors and actuators using Printed Electronics technology. For this, conductive, semiconductor and dielectric polymeric materials are used on flexible and/or elastic substrates. By means of suitable designs and application processes, it is possible to manufacture sensors capable of interacting with the environment. In this way, specific sensing functionalities can be incorporated into the substrates, such as textile fabrics. Additionally, it is necessary to include electronic systems capable of processing the data obtained, as well as its registration. In the development of these sensors and actuators, the physical properties of the different materials are precisely combined. For this, multilayer structures are designed where the properties of some materials interact with those of others. The result is a sensor capable of capturing physical variations of the environment, and convert them into signals that can be processed, and finally transformed into data. On the one hand, a tactile sensor printed on textile substrate for 2D gesture recognition was developed. This sensor consists of a matrix composed of small capacitive sensors based on a capacitor type structure. These sensors were designed in such a way that, if a finger or other object with capacitive properties, gets close enough, its behaviour varies, and it can be measured. The small sensors are arranged in this matrix as in a grid. Each sensor has a position that is determined by a row and a column. The capacity of each small sensor is periodically measured in order to assess whether significant variations have been produced. For this, it is necessary to convert the sensor capacity into a value that is subsequently digitally processed. On the other hand, to improve the effectiveness in the use of the developed 2D touch sensors, the way of incorporating an actuator system was studied. Thereby, the user receives feedback that the order or action was recognized. To achieve this, the capacitive sensor grid was complemented with an electroluminescent screen printed as well. The final prototype offers a solution that combines a 2D tactile sensor with an electroluminescent actuator on a printed textile substrate. Next, the development of a 3D gesture sensor was carried out using a combination of sensors also printed on textile substrate. In this type of 3D sensor, a signal is sent generating an electric field on the sensors. This is done using a transmission electrode located very close to them. The generated field is received by the reception sensors and converted to electrical signals. For this, the sensors are based on electrodes that act as receivers. If a person places their hands within the emission area, a disturbance of the electric field lines is created. This is due to the deviation of the lines to ground using the intrinsic conductivity of the human body. This disturbance affects the signals received by the electrodes. Variations captured by all electrodes are processed together and can determine the position and movement of the hand on the sensor surface. Finally, the development of an improved 3D gesture sensor was carried out. As in the previous development, the sensor allows contactless gesture detection, but increasing the detection range. In addition to printed electronic technology, two other textile manufacturing technologies were evaluated.[ES] La presente tesis doctoral tiene como objetivo fundamental el desarrollo de nuevos sensores y actuadores empleando la tecnología electrónica impresa, también conocida como Printed Electronics. Para ello, se emplean materiales poliméricos conductores, semiconductores y dieléctricos sobre sustratos flexibles y/o elásticos. Por medio de diseños y procesos de aplicación adecuados, es posible fabricar sensores capaces de interactuar con el entorno. De este modo, se pueden incorporar a los sustratos, como puedan ser tejidos textiles, funcionalidades específicas de medición del entorno y de respuesta ante cambios de este. Adicionalmente, es necesario incluir sistemas electrónicos, capaces de realizar el procesado de los datos obtenidos, así como de su registro. En el desarrollo de estos sensores y actuadores se combinan las propiedades físicas de los diferentes materiales de forma precisa. Para ello, se diseñan estructuras multicapa donde las propiedades de unos materiales interaccionan con las de los demás. El resultado es un sensor capaz de captar variaciones físicas del entorno, y convertirlas en señales que pueden ser procesadas y transformadas finalmente en datos. Por una parte, se ha desarrollado un sensor táctil impreso sobre sustrato textil para reconocimiento de gestos en 2D. Este sensor se compone de una matriz formada por pequeños sensores capacitivos basados en estructura de tipo condensador. Estos se han diseñado de forma que, si un dedo u otro objeto con propiedades capacitivas se aproxima suficientemente, su comportamiento varía, pudiendo ser medido. Los pequeños sensores están ordenados en dicha matriz como en una cuadrícula. Cada sensor tiene una posición que viene determinada por una fila y por una columna. Periódicamente se mide la capacidad de cada pequeño sensor con el fin de evaluar si ha sufrido variaciones significativas. Para ello es necesario convertir la capacidad del sensor en un valor que posteriormente es procesado digitalmente. Por otro lado, con el fin de mejorar la efectividad en el uso de los sensores táctiles 2D desarrollados, se ha estudiado el modo de incorporar un sistema actuador. De esta forma, el usuario recibe una retroalimentación indicando que la orden o acción ha sido reconocida. Para ello, se ha complementado la matriz de sensores capacitivos con una pantalla electroluminiscente también impresa. El resultado final ofrece una solución que combina un sensor táctil 2D con un actuador electroluminiscente realizado mediante impresión electrónica sobre sustrato textil. Posteriormente, se ha llevado a cabo el desarrollo de un sensor de gestos 3D empleando una combinación de sensores impresos también sobre sustrato textil. En este tipo de sensor 3D, se envía una señal que genera un campo eléctrico sobre los sensores impresos. Esto se lleva a cabo mediante un electrodo de transmisión situado muy cerca de ellos. El campo generado es recibido por los sensores y convertido a señales eléctricas. Para ello, los sensores se basan en electrodos que actúan de receptores. Si una persona coloca su mano dentro del área de emisión, se crea una perturbación de las líneas de los campos eléctricos. Esto es debido a la desviación de las líneas de campo a tierra utilizando la conductividad intrínseca del cuerpo humano. Esta perturbación cambia/afecta a las señales recibidas por los electrodos. Las variaciones captadas por todos los electrodos son procesadas de forma conjunta pudiendo determinar la posición y el movimiento de la mano sobre la superficie del sensor. Finalmente, se ha llevado a cabo el desarrollo de un sensor de gestos 3D mejorado. Al igual que el desarrollo anterior, permite la detección de gestos sin necesidad de contacto, pero incrementando la distancia de alcance. Además de la tecnología de impresión electrónica, se ha evaluado el empleo de otras dos tecnologías de fabricación textil.[CA] La present tesi doctoral té com a objectiu fonamental el desenvolupament de nous sensors i actuadors fent servir la tecnologia de electrònica impresa, també coneguda com Printed Electronics. Es va fer us de materials polimèrics conductors, semiconductors i dielèctrics sobre substrats flexibles i/o elàstics. Per mitjà de dissenys i processos d'aplicació adequats, és possible fabricar sensors capaços d'interactuar amb l'entorn. D'aquesta manera, es poden incorporar als substrats, com ara teixits tèxtils, funcionalitats específiques de mesurament de l'entorn i de resposta davant canvis d'aquest. Addicionalment, és necessari incloure sistemes electrònics, capaços de realitzar el processament de les dades obtingudes, així com del seu registre. En el desenvolupament d'aquests sensors i actuadors es combinen les propietats físiques dels diferents materials de forma precisa. Cal dissenyar estructures multicapa on les propietats d'uns materials interaccionen amb les de la resta. manera El resultat es un sensor capaç de captar variacions físiques de l'entorn, i convertirles en senyals que poden ser processades i convertides en dades. D'una banda, s'ha desenvolupat un sensor tàctil imprès sobre substrat tèxtil per a reconeixement de gestos en 2D. Aquest sensor es compon d'una matriu formada amb petits sensors capacitius basats en una estructura de tipus condensador. Aquests s'han dissenyat de manera que, si un dit o un altre objecte amb propietats capacitives s'aproxima prou, el seu comportament varia, podent ser mesurat. Els petits sensors estan ordenats en aquesta matriu com en una quadrícula. Cada sensor té una posició que ve determinada per una fila i per una columna. Periòdicament es mesura la capacitat de cada petit sensor per tal d'avaluar si ha sofert variacions significatives. Per a això cal convertir la capacitat del sensor a un valor que posteriorment és processat digitalment. D'altra banda, per tal de millorar l'efectivitat en l'ús dels sensors tàctils 2D desenvolupats, s'ha estudiat la manera d'incorporar un sistema actuador. D'aquesta forma, l'usuari rep una retroalimentació indicant que l'ordre o acció ha estat reconeguda. Per a això, s'ha complementat la matriu de sensors capacitius amb una pantalla electroluminescent també impresa. El resultat final ofereix una solució que combina un sensor tàctil 2D amb un actuador electroluminescent realitzat mitjançant impressió electrònica sobre substrat tèxtil. Posteriorment, s'ha dut a terme el desenvolupament d'un sensor de gestos 3D emprant una combinació d'un mínim de sensors impresos també sobre substrat tèxtil. En aquest tipus de sensor 3D, s'envia un senyal que genera un camp elèctric sobre els sensors impresos. Això es porta a terme mitjançant un elèctrode de transmissió situat molt a proper a ells. El camp generat és rebut pels sensors i convertit a senyals elèctrics. Per això, els sensors es basen en elèctrodes que actuen de receptors. Si una persona col·loca la seva mà dins de l'àrea d'emissió, es crea una pertorbació de les línies dels camps elèctrics. Això és a causa de la desviació de les línies de camp a terra utilitzant la conductivitat intrínseca de el cos humà. Aquesta pertorbació afecta als senyals rebudes pels elèctrodes. Les variacions captades per tots els elèctrodes són processades de manera conjunta per determinar la posició i el moviment de la mà sobre la superfície del sensor. Finalment, s'ha dut a terme el desenvolupament d'un sensor de gestos 3D millorat. A l'igual que el desenvolupament anterior, permet la detecció de gestos sense necessitat de contacte, però incrementant la distància d'abast. A més a més de la tecnologia d'impressió electrònica, s'ha avaluat emprar altres dues tecnologies de fabricació tèxtil.Ferri Pascual, J. (2020). Tactile and Touchless Sensors Printed on Flexible Textile Substrates for Gesture Recognition [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153075TESISCompendi

Light on horizontal interactive surfaces: Input space for tabletop computing

In the last 25 years we have witnessed the rise and growth of interactive tabletop research, both in academic and in industrial settings. The rising demand for the digital support of human activities motivated the need to bring computational power to table surfaces. In this article, we review the state of the art of tabletop computing, highlighting core aspects that frame the input space of interactive tabletops: (a) developments in hardware technologies that have caused the proliferation of interactive horizontal surfaces and (b) issues related to new classes of interaction modalities (multitouch, tangible, and touchless). A classification is presented that aims to give a detailed view of the current development of this research area and define opportunities and challenges for novel touch- and gesture-based interactions between the human and the surrounding computational environment. © 2014 ACM.This work has been funded by Integra (Amper Sistemas and CDTI, Spanish Ministry of Science and Innovation) and TIPEx (TIN2010-19859-C03-01) projects and Programa de Becas y Ayudas para la Realización de Estudios Oficiales de Máster y Doctorado en la Universidad Carlos III de Madrid, 2010

Proceedings of the 4th Workshop on Interacting with Smart Objects 2015

These are the Proceedings of the 4th IUI Workshop on Interacting with Smart Objects. Objects that we use in our everyday life are expanding their restricted interaction capabilities and provide functionalities that go far beyond their original functionality. They feature computing capabilities and are thus able to capture information, process and store it and interact with their environments, turning them into smart objects

A comprehensive framework for the rapid prototyping of ubiquitous interaction

In the interaction between humans and computational systems, many advances have been made in terms of hardware (e.g., smart devices with embedded sensors and multi-touch surfaces) and software (e.g., algorithms for the detection and tracking of touches, gestures and full body movements). Now that we have the computational power and devices to manage interactions between the physical and the digital world, the question is—what should we do? For the Human-Computer Interaction research community answering to this question means to materialize Mark Weiser’s vision of Ubiquitous Computing. In the desktop computing paradigm, the desktop metaphor is implemented by a graphical user interface operated via mouse and keyboard. Users are accustomed to employing artificial control devices whose operation has to be learned and they interact in an environment that inhibits their faculties. For example the mouse is a device that allows movements in a two dimensional space, thus limiting the twenty three degrees of freedom of the human’s hand. The Ubiquitous Computing is an evolution in the history of computation: it aims at making the interface disappear and integrating the information processing into everyday objects with computational capabilities. In this way humans would no more be forced to adapt to machines but, instead, the technology will harmonize with the surrounding environment. Conversely from the desktop case, ubiquitous systems make use of heterogeneous Input/Output devices (e.g., motion sensors, cameras and touch surfaces among others) and interaction techniques such as touchless, multi-touch, and tangible. By reducing the physical constraints in interaction, ubiquitous technologies can enable interfaces that endow more expressive power (e.g., free-hand gestures) and, therefore, such technologies are expected to provide users with better tools to think, create and communicate. It appears clear that approaches based on classical user interfaces from the desktop computing world do not fit with ubiquitous needs, for they were thought for a single user who is interacting with a single computing systems, seated at his workstation and looking at a vertical screen. To overcome the inadequacy of the existing paradigm, new models started to be developed that enable users to employ their skills effortlessly and lower the cognitive burden of interaction with computational machines. Ubiquitous interfaces are pervasive and thus invisible to its users, or they become invisible with successive interactions in which the users feel they are instantly and continuously successful. All the benefits advocated by ubiquitous interaction, like the invisible interface and a more natural interaction, come at a price: the design and development of interactive systems raise new conceptual and practical challenges. Ubiquitous systems communicate with the real world by means of sensors, emitters and actuators. Sensors convert real world inputs into digital data, while emitters and actuators are mostly used to provide digital or physical feedback (e.g., a speaker emitting sounds). Employing such variety of hardware devices in a real application can be difficult because their use requires knowledge of underneath physics and many hours of programming work. Furthermore, data integration can be cumbersome, for any device vendor uses different programming interfaces and communication protocols. All these factors make the rapid prototyping of ubiquitous systems a challenging task. Prototyping is a pivoting activity to foster innovation and creativity through the exploration of a design space. Nevertheless, while there are many prototyping tools and guidelines for traditional user interfaces, very few solutions have been developed for a holistic prototyping of ubiquitous systems. The tremendous amount of different input devices, interaction techniques and physical environments envisioned by researchers produces a severe challenge from the point of view of general and comprehensive development tools. All of this makes it difficult to work in a design and development space where practitioners need to be familiar with different related subjects, involving software and hardware. Moreover, the technological context is further complicated by the fact that many of the ubiquitous technologies have recently grown from an embryonic stage and are still in a process of maturation; thus they lack of stability, reliability and homogeneity. For these reasons, it is compelling to develop tools support to the programming of ubiquitous interaction. In this thesis work this particular topic is addressed. The goal is to develop a general conceptual and software framework that makes use of hardware abstraction to lighten the prototyping process in the design of ubiquitous systems. The thesis is that, by abstracting from low-level details, it is possible to provide unified, coherent and consistent access to interacting devices independently of their implementation or communication protocols. In this dissertation the existing literature is revised and is pointed out that there is a need in the art of frameworks that provide such a comprehensive and integrate support. Moreover, the objectives and the methodology to fulfill them, together with the major contributions of this work are described. Finally, the design of the proposed framework, its development in the form of a set of software libraries, its evaluation with real users and a use case are presented. Through the evaluation and the use case it has been demonstrated that by encompassing heterogeneous devices into a unique design it is possible to reduce user efforts to develop interaction in ubiquitous environments. --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------En la interacción entre personas y sistemas de computación se han realizado muchos adelantos por lo que concierne el hardware (p.ej., dispositivos inteligentes con sensores integrados y superficies táctiles) y el software (p.ej., algoritmos para el reconocimiento y rastreo de puntos de contactos, gestos de manos y movimientos corporales). Ahora que se dispone del poder computacional y de los dispositivos para proporcionar una interacción entre el mundo fisico y el mundo digital, la pregunta es—que se debería hacer? Contestar a esta pregunta, para la comunidad de investigación en la Interacción Persona-Ordenador, significa hacer realidad la visión de Mark Weiser sobre la Computación Ubicua. En el paradigma de computación de escritorio, la metáfora del escritorio se implementa a través de la interfaz gráfica de usuario con la que se interactúa a través de teclado y ratón. En este paradigma, los usuarios se adaptan a utilizar dispositivos artificiales, cuyas operaciones deben ser aprendidas, y a interactuar en un entorno que inhibe sus capacidades. Por ejemplo, el ratón es un dispositivo que permite movimientos en dos dimensiones, por tanto limita los veintitrés grados de libertad de una mano. La Computación Ubicua se considera como una evolución en la historia de la computación: su objetivo es hacer que la interfaz desaparezca e integrar el procesamiento de la información en los objetos cotidianos, provistos de capacidad de computo. De esta forma, el usuario no se vería forzado a adaptarse a la maquinas sino que la tecnología se integrarían directamente con el entorno. A diferencia de los sistemas de sobremesa, los sistemas ubicuos utilizan dispositivos de entrada/salida heterogéneos (p.ej., sensores de movimiento, cameras y superficies táctiles entre otros) y técnicas de interacción como la interacción sin tocar, multitáctil o tangible. Reduciendo las limitaciones físicas en la interacción, las tecnologías ubicuas permiten la creación de interfaces con un mayor poder de expresión (p.ej., gestos con las manos) y, por lo tanto, se espera que proporcionen a los usuarios mejores herramientas para pensar, crear y comunicar. Parece claro que las soluciones basadas en las interfaces clásicas no satisfacen las necesidades de la interacción ubicua, porque están pensadas por un único usuario que interactúa con un único sistema de computación, sentado a su mesa de trabajo y mirando una pantalla vertical. Para superar las deficiencias del paradigma de escritorio, se empezaron a desarrollar nuevos modelos de interacción que permitiesen a los usuarios emplear sin esfuerzo sus capacidades innatas y adquiridas y reducir la carga cognitiva de las interfaces clásicas. Las interfaces ubicuas son pervasivas y, por lo tanto, invisibles a sus usuarios, o devienen invisibles a través de interacciones sucesivas en las que los usuarios siempre se sienten que están teniendo éxito. Todos los beneficios propugnados por la interacción ubicua, como la interfaz invisible o una interacción mas natural, tienen un coste: el diseño y el desarrollo de sistemas de interacción ubicua introducen nuevos retos conceptuales y prácticos. Los sistemas ubicuos comunican con el mundo real a través de sensores y emisores. Los sensores convierten las entradas del mundo real en datos digitales, mientras que los emisores se utilizan principalmente para proporcionar una retroalimentación digital o física (p.ej., unos altavoces que emiten un sonido). Emplear una gran variedad de dispositivos hardware en una aplicación real puede ser difícil, porque su uso requiere conocimiento de física y muchas horas de programación. Además, la integración de los datos puede ser complicada, porque cada proveedor de dispositivos utiliza diferentes interfaces de programación y protocolos de comunicación. Todos estos factores hacen que el prototipado rápido de sistemas ubicuos sea una tarea que constituye un difícil reto en la actualidad. El prototipado es una actividad central para promover la innovación y la creatividad a través de la exploración de un espacio de diseño. Sin embargo, a pesar de que existan muchas herramientas y líneas guías para el prototipado de las interfaces de escritorio, a día de hoy han sido desarrolladas muy pocas soluciones para un prototipado holístico de la interacción ubicua. La enorme cantidad de dispositivos de entrada, técnicas de interacción y entornos físicos concebidos por los investigadores supone un gran desafío desde el punto de vista de un entorno general e integral. Todo esto hace que sea difícil trabajar en un espacio de diseño y desarrollo en el que los profesionales necesitan tener conocimiento de diferentes materias relacionadas con temas de software y hardware. Además, el contexto tecnológico se complica por el hecho que muchas de estas tecnologías ubicuas acaban de salir de un estadio embrionario y están todavía en un proceso de desarrollo; por lo tanto faltan de estabilidad, fiabilidad y homogeneidad. Por estos motivos es fundamental desarrollar herramientas que soporten el proceso de prototipado de la interacción ubicua. Este trabajo de tesis doctoral se dedica a este problema. El objetivo es desarrollar una arquitectura conceptual y software que utilice un nivel de abstracción del hardware para hacer mas fácil el proceso de prototipado de sistemas de interacción ubicua. La tesis es que, abstrayendo de los detalles de bajo nivel, es posible proporcionar un acceso unificado, consistente y coherente a los dispositivos de interacción independientemente de su implementación y de los protocolos de comunicación. En esta tesis doctoral se revisa la literatura existente y se pone de manifiesto la necesidad de herramientas y marcos que proporcionen dicho soporte global e integrado. Además, se describen los objetivos propuestos, la metodología para alcanzarlos y las contribuciones principales de este trabajo. Finalmente, se presentan el diseño del marco conceptual, así como su desarrollo en forma de un conjunto de librerías software, su evaluación con usuarios reales y un caso de uso. A través de la evaluación y del caso de uso se ha demostrado que considerando dispositivos heterogéneos en un único diseño es posible reducir los esfuerzos de los usuarios para desarrollar la interacción en entornos ubicuos

Robotic arm gripper using force sensor for crop picking mechanism

A dynamic gripper with qualities that resemble the human hand as closely as possible is sought after in the field of robotics. The idea of a robotic arm has been used invarious cutting-edge technology fields, including agriculture,to assist people or farmers in carrying out regular tasks, such as gathering fruit, etc.The robot arm's end effector is one of the essential parts of the robot that we can configure based on their tasks, such as a spraying adaptor for fertilization function or a gripper for the picking mechanism. Since fruits have a delicate and fragile surfaces, it is vital to have a gripper with a smooth contact surface that can apply the right amount of force to pick the fruits without causing any bruising that can degrade the crop's quality. Hence, this paper proposes a robotic arm gripper design for the crop-picking mechanism using a force sensor as the main component of the Arduino Uno embedded system. There liability result for the chili obtained is around 95% showing that this design is promising for designing an adaptive robotic arm gripper

EM-skin:an artificial robotic skin using magnetic inductance tomography

Physical sensing by touch is essential for building intelligent artificial systems in robotic manipulation and human-robotic interaction. Inductive skins are being investigated as part of a major effort to develop the most robust and reliable touch sensors, primarily based on traditional inductive proximity sensing. Magnetic induction tomography (MIT) is an imaging system considered for medical diagnostics and industrial process monitoring. This article presents a novel electromagnetic-based skin (EM-skin) using the MIT imaging system. This is done by processing the mutual inductance data from a planar array sensing a skin-like medium, including an elastomeric medium that interfaces the MIT sensors with plates of metallic or magnetic touch elements. This article demonstrates EM-based multi-touch, dynamical touch, and quantitative touch pressure sensing. MIT data are captured at 10 frames/s, so allowing for dynamical touch analysis. The EM-skin sensing area of 900 mm demonstrates a large area of sensing skin. The results show the successful reconstruction of dynamical sensing, where two applied cyclic touch points, with different frequencies are discriminately detected. Quantitative force sensing shows the detection of a minimum of 120 mN force, which translates to 0.38 kP of applied pressure in the described system. Further force calibration is carried out demonstrating the quantitative nature of the proposed EM skin. These results will open the way to a new generation of distributed and reliable soft skins that are versatile due to material design and processing.</p

EM-skin:an artificial robotic skin using magnetic inductance tomography

Physical sensing by touch is essential for building intelligent artificial systems in robotic manipulation and human-robotic interaction. Inductive skins are being investigated as part of a major effort to develop the most robust and reliable touch sensors, primarily based on traditional inductive proximity sensing. Magnetic induction tomography (MIT) is an imaging system considered for medical diagnostics and industrial process monitoring. This article presents a novel electromagnetic-based skin (EM-skin) using the MIT imaging system. This is done by processing the mutual inductance data from a planar array sensing a skin-like medium, including an elastomeric medium that interfaces the MIT sensors with plates of metallic or magnetic touch elements. This article demonstrates EM-based multi-touch, dynamical touch, and quantitative touch pressure sensing. MIT data are captured at 10 frames/s, so allowing for dynamical touch analysis. The EM-skin sensing area of 900 mm demonstrates a large area of sensing skin. The results show the successful reconstruction of dynamical sensing, where two applied cyclic touch points, with different frequencies are discriminately detected. Quantitative force sensing shows the detection of a minimum of 120 mN force, which translates to 0.38 kP of applied pressure in the described system. Further force calibration is carried out demonstrating the quantitative nature of the proposed EM skin. These results will open the way to a new generation of distributed and reliable soft skins that are versatile due to material design and processing.</p

Practical, appropriate, empirically-validated guidelines for designing educational games

There has recently been a great deal of interest in the potential of computer games to function as innovative educational tools. However, there is very little evidence of games fulfilling that potential. Indeed, the process of merging the disparate goals of education and games design appears problematic, and there are currently no practical guidelines for how to do so in a coherent manner. In this paper, we describe the successful, empirically validated teaching methods developed by behavioural psychologists and point out how they are uniquely suited to take advantage of the benefits that games offer to education. We conclude by proposing some practical steps for designing educational games, based on the techniques of Applied Behaviour Analysis. It is intended that this paper can both focus educational games designers on the features of games that are genuinely useful for education, and also introduce a successful form of teaching that this audience may not yet be familiar with

Dynamic motion coupling of body movement for input control

Touchless gestures are used for input when touch is unsuitable or unavailable, such as when interacting with displays that are remote, large, public, or when touch is prohibited for hygienic reasons. Traditionally user input is spatially or semantically mapped to system output, however, in the context of touchless gestures these interaction principles suffer from several disadvantages including memorability, fatigue, and ill-defined mappings. This thesis investigates motion correlation as the third interaction principle for touchless gestures, which maps user input to system output based on spatiotemporal matching of reproducible motion. We demonstrate the versatility of motion correlation by using movement as the primary sensing principle, relaxing the restrictions on how a user provides input. Using TraceMatch, a novel computer vision-based system, we show how users can provide effective input through investigation of input performance with different parts of the body, and how users can switch modes of input spontaneously in realistic application scenarios. Secondly, spontaneous spatial coupling shows how motion correlation can bootstrap spatial input, allowing any body movement, or movement of tangible objects, to be appropriated for ad hoc touchless pointing on a per interaction basis. We operationalise the concept in MatchPoint, and demonstrate the unique capabilities through an exploration of the design space with application examples. Finally, we explore how users synchronise with moving targets in the context of motion correlation, revealing how simple harmonic motion leads to better synchronisation. Using the insights gained we explore the robustness of algorithms used for motion correlation, showing how it is possible to successfully detect a user's intent to interact whilst suppressing accidental activations from common spatial and semantic gestures. Finally, we look across our work to distil guidelines for interface design, and further considerations of how motion correlation can be used, both in general and for touchless gestures