Robot Control and Programming: Class notes.

The term robot is quite complex because it can mean different things to different people. Mostly, it recalls us images of science fiction robots, such as the famous C3PO and R2D2 of Star Wars Trilogy. However, we have to focus on other types, and wait a little for the progress of the technology. If we focus on the real robots, we can find different types. However, the vast majority are classified into the industrial robot category. Industrial robots are recognised easily since their shape usually reminds the human arm. The term industrial shows the fact that those robots work in factories as components of larger manufacturing systems and processes. This book are focused on the lectures that Emilio Sánchez delivers in the frame of Robot Control and Programing subject in TECNUN, where the reader can find and introduction to the basic problems and control and programming techniques of industrial robots. Despite the fact the book is based on classnotes, the author prepared them very carefully to give to them the appearance of a real book. The book starts with a discussion about what is and what isn't a robot, classification and a very brief note about robotics history. The course will cover the different and basic programming and control strategies. Another issue discussed will be the morphology classification. The most important section is the kinematics model. This problem can be solved by means of Denavit-Hartenberg method and homogeneous transformations among coordinate systems. The last chapters are devoted to position control strategies and path planning. Finally the author encourages the reader to open and read this book since he really thinks that Robotics is a very large and interesting field, involving many different disciplines: mechanical design, sensors, actuation (pneumatic, hydraulic, electrical...), control, programming... For this reason, the term mechatronics is also used to express the link between the mechanics and electronics

Development of a general purpose cooperative shared-control robot assistant for performance of surgical procedures involving bone machining

Currently, the interest on robotics for healthcare applications has grown rapidly, due to the remarkable advantages that robotic technologies introduce into the medical field such as enhancing the precision and accuracy of the medical practitioner, providing remote healthcare services with audiovisual and tactile feedback, quantitative assessment of performance, realization of pre-operative planning of interventions and automation of repetitive tasks. Among the various fields of medicine in which robotic devices can be of use, the denomination robotic surgery is used to refer to those technological developments including robotic devices in the performance of surgical procedures. Those have the potential to improve the outcome of surgical interventions by ensuring levels of precision and dexterity unattainable by other means, thus resulting in safer procedures for the patients (reduced risk of infection, less blood loss and scarring due to performance of minimally invasive interventions). This research work presents an innovative surgical workstation developed at CEIT in collaboration with CUN that is intended for general surgical procedures involving bone machining. The performance of the platform has been optimized for a surgical procedure that can be greatly benefitted from the introduction of a surgical robot assistant, which is transpedicular spinal fusion. The key feature of this platform is that it can work under a number of complementary operation paradigms. For instance, it can work in combination with a customized surgical planner and navigation system, which transmit to the robot the optimal approach for performing the surgical task. However, the main operating mode is the cooperative shared-control paradigm, in which the surgeon physically holds the robot assistant (hands-on robot) and the exerted forces (measured by a force/torque sensor) are proportionally translated to motions of the robot. A distinctive characteristic of cooperative devices (which is shared with teleoperated robots) is that trajectories are generated in real-time. Furthermore, for the case of robotic surgery robots usually work in a highly dynamic, unstructured environment that is not characterized a priori so global information is not usually available for optimization of control algorithms. This work is concerned with the development and improvement of the robot assistant integrated in the surgical system, by designing and building the necessary hardware elements as well as conceiving and programming suitable control algorithms according to the operation paradigms implemented in the system. In this sense, ensuring a stable and robust performance of the system is vital for validating the surgical platform. Therefore, several control algorithms are proposed in this work, which have been conceived for operation under the online trajectory generation paradigm, that allow a safer and more stable operation of the robot assistant: a strategy for management of unstable singular configurations of the manipulator and resolution of the inverse kinematics problem is introduced in this work; a suitable adaptive admittance controller for working under the cooperative operation paradigm that allows tremor filtering, correction of the intentional trajectory error and adjustment to human operator force and motion characteristics is presented too; finally, a virtual fixtures module, developed for guidance during surgical procedures is implemented for safer and accurate performance of surgery. Also, an automated rotary tool for drilling operations designed for this surgical platform is proposed in this work. Given the possible incidence of thermal osteo-necrosis phenomena during the bone machining procedures, a predictive algorithm for assessment of these phenomena has been developed in order to control the performance of the automated drilling tool

International Conference on Multimodal Interfaces for Skills Transfer.

This volume collects the work presented at the 1st international Conference on Multimodal interfaces for Skills Transfer (SKILLS09), held in Bilbao (Spain) on 15th -16th December, 2009, and promoted by the European SKILLS Integrated Project. SKILLS09 is a major forum for researchers in the field of Multimodal Interfaces for human Skills transfer. Training on human skills is state-of-the-art research on Human-Machine-Interfaces (HMI) and Psychology. There are many manual skills and activities where human learners find the symbolic and iconic information difficult to remap into movement patterns. Something that is represented in an objective space must be translated into the subjective space of the body, where many actions are automatic and not consciously controlled. Enactive representations of the task seek to bridge this gap. Enactive knowledge is not simply multisensory mediated knowledge, but knowledge stored in the form of motor responses and acquired by the act of “doing”. A typical example of enactive knowledge is constituted by the competence required for tasks such as driving a car, playing a musical instrument, modelling objects from clay, performing sports, etc., which would be difficult to describe in an iconic or symbolic form. This type of knowledge transmission can be considered the most direct, in natural and intuitive terms, since it is based on the experience and on the perceptual responses to motor acts. This conference presents and discusses recent developments in the application of the concept of Enaction for the transfer of manual human skills, that is, “Enaction on Skills”. Thus, the presented papers cover topics related to skills conceptualization and transfer process, from expert’s skills capturing to skill rendering and assessment, without forgetting the required technologies that enable this process. Finally, we want to thank everyone that made possible this conference: authors, LABEIN, CEIT, SKILLS consortium, European Union, Basque Government and all committee members for the high quality of work they have done

Development of a general purpose cooperative shared-control robot assistant for performance of surgical procedures involving bone machining

Currently, the interest on robotics for healthcare applications has grown rapidly, due to the remarkable advantages that robotic technologies introduce into the medical field such as enhancing the precision and accuracy of the medical practitioner, providing remote healthcare services with audiovisual and tactile feedback, quantitative assessment of performance, realization of pre-operative planning of interventions and automation of repetitive tasks. Among the various fields of medicine in which robotic devices can be of use, the denomination robotic surgery is used to refer to those technological developments including robotic devices in the performance of surgical procedures. Those have the potential to improve the outcome of surgical interventions by ensuring levels of precision and dexterity unattainable by other means, thus resulting in safer procedures for the patients (reduced risk of infection, less blood loss and scarring due to performance of minimally invasive interventions). This research work presents an innovative surgical workstation developed at CEIT in collaboration with CUN that is intended for general surgical procedures involving bone machining. The performance of the platform has been optimized for a surgical procedure that can be greatly benefitted from the introduction of a surgical robot assistant, which is transpedicular spinal fusion. The key feature of this platform is that it can work under a number of complementary operation paradigms. For instance, it can work in combination with a customized surgical planner and navigation system, which transmit to the robot the optimal approach for performing the surgical task. However, the main operating mode is the cooperative shared-control paradigm, in which the surgeon physically holds the robot assistant (hands-on robot) and the exerted forces (measured by a force/torque sensor) are proportionally translated to motions of the robot. A distinctive characteristic of cooperative devices (which is shared with teleoperated robots) is that trajectories are generated in real-time. Furthermore, for the case of robotic surgery robots usually work in a highly dynamic, unstructured environment that is not characterized a priori so global information is not usually available for optimization of control algorithms. This work is concerned with the development and improvement of the robot assistant integrated in the surgical system, by designing and building the necessary hardware elements as well as conceiving and programming suitable control algorithms according to the operation paradigms implemented in the system. In this sense, ensuring a stable and robust performance of the system is vital for validating the surgical platform. Therefore, several control algorithms are proposed in this work, which have been conceived for operation under the online trajectory generation paradigm, that allow a safer and more stable operation of the robot assistant: a strategy for management of unstable singular configurations of the manipulator and resolution of the inverse kinematics problem is introduced in this work; a suitable adaptive admittance controller for working under the cooperative operation paradigm that allows tremor filtering, correction of the intentional trajectory error and adjustment to human operator force and motion characteristics is presented too; finally, a virtual fixtures module, developed for guidance during surgical procedures is implemented for safer and accurate performance of surgery. Also, an automated rotary tool for drilling operations designed for this surgical platform is proposed in this work. Given the possible incidence of thermal osteo-necrosis phenomena during the bone machining procedures, a predictive algorithm for assessment of these phenomena has been developed in order to control the performance of the automated drilling tool

Development of methodology for the characterisation and modelling of soft tissues for real-time simulation. Application to the modelling of the viscoelastic mechanical response of brain tissue.

The characterisation of the mechanical properties of biological soft tissues is of great interest for many applications in the bioengineering field: such as for the detection of tumours and diseases, for the development of medical assistive and surgical technologies. These technologies include surgery simulation, which based on computational methods, reproduces surgical procedures in order to develop the skills of the surgeon, to plan operations or to provide technical support to surgeon during the operation. However, modelling the physical behaviour of human organs and tissues remains a challenge. This is due to the difficulty in characterising the physical properties of biological soft tissues. Besides, the challenge lies on the computation time requirements for real-time simulations. Surgical real-time simulation should employ a sufficiently precise and simple model in order to provide a realistic tactile and visual feedback. To address these difficulties, this thesis presents a methodology for the characterisation and modelling of the mechanical properties of soft tissues, for its integration into real-time surgical simulators. The characterisation is performed in the laboratory using a parallel plate rheometer. The methodology has been applied to synthetic materials such as agar gel, as well as to biological tissues such as porcine brain tissue. By performing this characterisation, different mathematical models have been analysed and developed for the modelling of the selected tissues. These models have been studied in order to select the most appropriate one, depending on the specific requirements of the simulator.La caracterización y modelado de las propiedades mecánicas de tejidos biológicos blandos resulta de gran interés para diversas aplicaciones en el ámbito de la bioingeniería, como por ejemplo, para la detección de tumores y enfermedades, así como para tecnologías de asistencia médica y quirúrgica. Entre estas tecnologías está la simulación quirúrgica, que basándose en métodos computacionales, reproduce procedimientos quirúrgicos con el fin de desarrollar las habilidades del cirujano, planificar operaciones o proporcionar técnicas de apoyo al cirujano durante la operación. Sin embargo, la modelización del comportamiento físico de los órganos y tejidos humanos sigue siendo un desafío. Por una parte, esto es debido a la dificultad para caracterizar las propiedades físicas de los tejidos blandos. Por otro lado, el reto reside en los requerimientos de tiempo de cálculo que se necesita en la simulación, cuando ésta se quiere realizar en tiempo real, siendo el mayor interés el minimizar estos tiempos. Con el fin de hacer frente a estas dificultades, en esta tesis se ha desarrollado una metodología para la caracterización y el modelado de las propiedades mecánicas de tejidos blandos para su integración en simuladores quirúrgicos. La caracterización se ha llevado a cabo en el laboratorio mediante un reómetro de platos paralelos. La metodología se ha aplicado a materiales sintéticos, como el gel de agar, así como a tejidos biológicos, como el tejido cerebral porcino. Mediante la realización de esta caracterización, se han analizado y desarrollado diferentes modelos matemáticos para los tejidos elegidos. Se han estudiado estos modelos, con el fin de seleccionar el más adecuado en función de los requerimientos del simulador

Collaborative human–robot interaction interface: development for a spinal surgery robotic assistan

The growing introduction of robotics in non-industrial applications where the environment is unstructured and changing, has led to the need of development of safer and more intuitive, human-robot interfaces. In such environments, the use of collaborative robots has potential benefits, due to the combination of user experience, knowledge and flexibility with the robot's accuracy, stiffness and repeatability. Nevertheless, in order to guarantee a functional collaboration in these environments, the interaction between user and robot must be intuitive, natural, fast and easy to use. On one hand, commercial collaborative robots are less accurate and less stiff than the traditional industrial ones, on the other hand, the later have not intuitive interaction interfaces. There are tasks in which the stiffness of industrial robots and the intuitive interaction interfaces of collaborative commercial robots, are desirable. This is the case of some robotic assisted surgical procedures, such as robotic assisted spine surgery, with high accuracy demands and with the need of intuitive surgeon-robot interaction. This paper presents a hand guiding methodology for functional human-robot collaboration and the introduction of novel algorithms to enhance its behavior. Also its implementation on a robotic surgical assistant for spine procedures is presented. It is emphasized how a traditional industrial robot can be used as a collaborative one when the available commercial collaborative robots do not have the required accuracy and stiffness for the task

Lower-limb robotic rehabilitation. Literature review and challenges

This paper presents a survey of existing robotic systems for lower-limb rehabilitation. It is a general assumption that robotics will play an important role in therapy activities within rehabilitation treatment. In the last decade, the interest in the field has grown exponentially mainly due to the initial success of the early systems and the growing demand caused by increasing numbers of stroke patients and their associate rehabilitation costs. As a result, robot therapy systems have been developed worldwide for training of both the upper and lower extremities. This work reviews all current robotic systems to date for lower-limb rehabilitation, as well as main clinical tests performed with them, with the aim of showing a clear starting point in the field. It also remarks some challenges that current systems still have to meet in order to obtain a broad clinical and market acceptance

Implementación de un sistema teleoperado con reflexión de fuerza de seis grados de libertad

Los trabajos expuestos en la presente tesis se han realizado en el Centro de Estudios e Investigaciones Técnicas de Guipúzcoa (CEIT) dentro del marco establecido en el proyecto de Sistemas Robóticos Teleoperados (SRT), financiado por Iberdrola y Equipos Nucleares (S.A.). El principal objetivo del SRT ha sido desarrollar una familia de robots que ayuden en tareas de mantenimiento de centrales nucleares. Un dispositivo de teleoperación consta de dos manipuladores: el robot maestro está controlado por un operario mientras que el esclavo interactúa con un entorno remoto, siguiendo las trayectorias comandadas desde el maestro. La característica de reflexión de fuerza hace referencia al hecho por el cual las fuerzas de interacción, del robot esclavo con su entorno, se reconducen al operario a través del robot maestro. La principal motivación del estudio de estos dispositivos es la de poder desempeñar, con un alto grado de destreza, tareas en entornos remotos y hostiles para el operario humano. Partiendo de los estudios de tesis anteriores en el laboratorio de robótica del CEIT, el objetivo de la presente consiste en ampliar y finalizar los trabajos realizados sobre un prototipo de teleoperación de seis grados de libertad. Todo ello ha supuesto: Diseñar e implementar un controlador de teleoperación con reflexión de fuerza que contemple tanto las dinámicas de traslación y rotación, en el espacio cartesiano, de los robots involucrados. Diseñar e Implementar un algoritmo que mantenga a los robots alejados de sus configuraciones singulares y límites de sus espacios de trabajo. Ensayar y testear todos los algoritmos sobre un prototipo real. La exposición comienza con una pequeña introducción, historia y estado de la técnica de los sistemas teleoperados en el primer capítulo. A continuación, en el capítulo 2, se describe el prototipo de teleoperación desarrollado. Este prototipo consta, como robot maestro, de una plataforma Stewart, y, como esclavo, de un robot antropomórfico. El capítulo 3 estudia únicamente la cinemática del robot esclavo, ya que la del maestro se contempla en estudios anteriores si bien puede encontrarse un resumen en el Anejo A. En el capítulo 4, se muestra con detalle los lazos de control de teleoperación propuesto. Este algoritmo se clasifica como esquema de control fuerza-fuerza ya que la información comunicada entre ambos robots es la fuerza medida en cada uno de ellos. Este esquema tiene la ventaja de ser el más transparente, es decir, tiene gran capacidad para reproducir en el operador las mismas fuerzas que éste sentiría en caso de que estuviera trabajando directamente en el entorno remoto. Por el contrario, estos esquemas tienden a ser inestables. Por ello, también se contempla la modificación adaptativa de ciertas variables para evitar este problema y la adición de unos lazos de prealimentación local y remota de fuerzas. El capítulo 5 expone un algoritmo para evitar configuraciones singulares y límites del espacio de trabajo tanto del robot maestro como del esclavo. Este algoritmo define los subespacios óptimos de trabajo para cada robot, y establece unos límites que el controlador impide que se sobrepasen. La estrategia empleada se basa en reflejar al operario una fuerza que simula el comportamiento de unos muelles. En el capítulo 6 se analiza el comportamiento de los algoritmos propuestos en el capítulo 5 y se muestran los resultados experimentales de la ejecución de tres tareas teleoperadas (manipulación, taladrado y amolado). Finalmente, en el capítulo 7 se resumen las conclusiones extraídas a lo largo del todo el trabajo y futuras líneas de investigación. Este proyecto ha sido cofinanciado parcialmente por la CICYT bajo el número de registro TAP95-0227-C02-02 y realizado conjuntamente por el CEIT, Iberdrola, Endesa, Equipos Nucleares S.A. y la Universidad de Cantabria

Implementación de un sistema teleoperado con reflexión de fuerza de seis grados de libertad

Los trabajos expuestos en la presente tesis se han realizado en el Centro de Estudios e Investigaciones Técnicas de Guipúzcoa (CEIT) dentro del marco establecido en el proyecto de Sistemas Robóticos Teleoperados (SRT), financiado por Iberdrola y Equipos Nucleares (S.A.). El principal objetivo del SRT ha sido desarrollar una familia de robots que ayuden en tareas de mantenimiento de centrales nucleares. Un dispositivo de teleoperación consta de dos manipuladores: el robot maestro está controlado por un operario mientras que el esclavo interactúa con un entorno remoto, siguiendo las trayectorias comandadas desde el maestro. La característica de reflexión de fuerza hace referencia al hecho por el cual las fuerzas de interacción, del robot esclavo con su entorno, se reconducen al operario a través del robot maestro. La principal motivación del estudio de estos dispositivos es la de poder desempeñar, con un alto grado de destreza, tareas en entornos remotos y hostiles para el operario humano. Partiendo de los estudios de tesis anteriores en el laboratorio de robótica del CEIT, el objetivo de la presente consiste en ampliar y finalizar los trabajos realizados sobre un prototipo de teleoperación de seis grados de libertad. Todo ello ha supuesto: Diseñar e implementar un controlador de teleoperación con reflexión de fuerza que contemple tanto las dinámicas de traslación y rotación, en el espacio cartesiano, de los robots involucrados. Diseñar e Implementar un algoritmo que mantenga a los robots alejados de sus configuraciones singulares y límites de sus espacios de trabajo. Ensayar y testear todos los algoritmos sobre un prototipo real. La exposición comienza con una pequeña introducción, historia y estado de la técnica de los sistemas teleoperados en el primer capítulo. A continuación, en el capítulo 2, se describe el prototipo de teleoperación desarrollado. Este prototipo consta, como robot maestro, de una plataforma Stewart, y, como esclavo, de un robot antropomórfico. El capítulo 3 estudia únicamente la cinemática del robot esclavo, ya que la del maestro se contempla en estudios anteriores si bien puede encontrarse un resumen en el Anejo A. En el capítulo 4, se muestra con detalle los lazos de control de teleoperación propuesto. Este algoritmo se clasifica como esquema de control fuerza-fuerza ya que la información comunicada entre ambos robots es la fuerza medida en cada uno de ellos. Este esquema tiene la ventaja de ser el más transparente, es decir, tiene gran capacidad para reproducir en el operador las mismas fuerzas que éste sentiría en caso de que estuviera trabajando directamente en el entorno remoto. Por el contrario, estos esquemas tienden a ser inestables. Por ello, también se contempla la modificación adaptativa de ciertas variables para evitar este problema y la adición de unos lazos de prealimentación local y remota de fuerzas. El capítulo 5 expone un algoritmo para evitar configuraciones singulares y límites del espacio de trabajo tanto del robot maestro como del esclavo. Este algoritmo define los subespacios óptimos de trabajo para cada robot, y establece unos límites que el controlador impide que se sobrepasen. La estrategia empleada se basa en reflejar al operario una fuerza que simula el comportamiento de unos muelles. En el capítulo 6 se analiza el comportamiento de los algoritmos propuestos en el capítulo 5 y se muestran los resultados experimentales de la ejecución de tres tareas teleoperadas (manipulación, taladrado y amolado). Finalmente, en el capítulo 7 se resumen las conclusiones extraídas a lo largo del todo el trabajo y futuras líneas de investigación. Este proyecto ha sido cofinanciado parcialmente por la CICYT bajo el número de registro TAP95-0227-C02-02 y realizado conjuntamente por el CEIT, Iberdrola, Endesa, Equipos Nucleares S.A. y la Universidad de Cantabria