The technological growth in the last years have conducted to the development of virtual reality (VR) systems able to immerse the user into a three-dimensional (3D) virtual environment where the user can interact in real time with virtual objects. This interaction is mainly based on visualizing the virtual environment and objects. However, with the recent beginning of haptic systems, the interaction with the virtual world has been extended to also feel, touch and manipulate virtual objects. Virtual reality has been successfully used in the development of applications in different scientific areas ranging from basic sciences, social science, education and entertainment. On the other hand, the use of haptics has increased in the last decade in domains from sciences and engineering to art and entertainment. Despite many developments, there is still relatively little knowledge about the confluence of software, enabling hardware, visual and haptic representations, to enable the conditions that best provide for an immersive sensory environment to convey information about a particular subject domain. In this paper, the state of the art of the research work regarding virtual reality and haptic technologies carried out by the authors in the last years is presented. The aim is to evidence the potential use of these technologies to develop usable systems for analysis and simulation in different areas of knowledge. The development of three different systems in the areas of engineering, medicine and art is presented. In the area of engineering, a system for the planning, evaluation and training of assembly and manufacturing tasks has been developed. The system, named as HAMS (Haptic Assembly and Manufacturing System), is able to simulate assembly tasks of complex components with force feedback provided by the haptic device. On the other hand, in the area of medicine, a surgical simulator for planning and training orthognathic surgeries has been developed. The system, named as VOSS (Virtual Osteotomy Simulator System), allows the realization of virtual osteotomies with force feedback. Finally, in the area of art, an interactive cinema system for blind people has been developed. The system is able to play a 3D virtual movie for the blind user to listen to and touch by means of the haptic device. The development of these applications and the results obtained from these developments are presented and discussed in this paper.

Virtual Reality (VR) is one of the areas of knowledge that have taken advantage of the computer technological development and scientific visualization. It has been used in different applications such as engineering, medicine, education, entertainment, astronomy, archaeology and arts. A main issue of VR and computer assisted applications is the design and development of the virtual environment, which comprises the virtual objects. Thus, the process of designing virtual environment requires the modelling of the virtual scene and virtual objects, including their geometry and surface characteristics such as colours, textures, etc. This research work presents a new methodology to develop low-cost and high quality virtual environments and scenarios for biomechanics, biomedical and engineering applications. The proposed methodology is based on open-source software. Four case studies corresponding to two applications in medicine and two applications in engineering are presented. The results show that the virtual environments developed for these applications are realistic and similar to the real environments. When comparing these virtual reality scenarios with pictures of the actual devices, it can be observed that the appearance of the virtual scenarios is very good. In particular the use of textures greatly helps in assessing specific features such as simulation of bone or metal. Thus, the usability of the proposed methodology for developing virtual reality applications in biomedical and engineering is proved. It is important to mention that the quality of the virtual environment will also depend on the 3D modelling skills of the VR designer.

Advances in research on humanoid robots in recent years have brought a decrease in manufacturing costs due to design improvements and increased applications as assistants in certain tasks. Likewise, the miniaturization of electronic components and the proper use of simulation platforms used to evaluate the performance before construction permit dissemination and use of robots in most areas. The objective of this work is the design of a humanoid robot with basic capabilities of motion and with a minimum of actuators for walking, in this case of a single motor to generate the path of movement of the mechanism. By using closed kinematic chains and kinematic analysis is intended to provide an alternative to common practical solution, which uses an actuator for each joint in a biped humanoid robot. The kinematic synthesis is based on the trajectories described by human movement. The results show that it is possible to use a small number of actuators to achieve the motion of a humanoid robot, three. Keywords: Humanoid robot, kinematic analysis, four-link mechanism.Resumen-Los avances en investigaciones sobre los robots humanoides en los últimos años han traído una disminución en los costos de fabricación debido al perfeccionamiento de su diseño y el incremento de sus aplicaciones como asistentes en ciertas tareas. Así mismo la miniaturización de los componentes electrónicos y el buen uso de plataformas de simulación usadas para evaluar el desempeño antes de su construcción permiten la difusión y la utilización de robots en más áreas. El objetivo del presente trabajo es el diseño de un robot humanoide con capacidades básicas de movimiento y con un mínimo de actuadores para el caminado, en este caso de un solo motor, para generar la trayectoria de movimiento del mecanismo. Mediante el uso de cadenas cinemáticas cerradas y el análisis cinemático se pretende proporcionar una solución alternativa a la práctica común, la cual usa un actuador por cada articulación en un robot humanoide bípedo. La síntesis cinemática está basada en las trayectorias descritas por el movimiento humano. Los resultados obtenidos demuestran que es posible utilizar un número reducido de actuadores para lograr el movimiento de un robot humanoide, tres en total. Palabras clave: Robot humanoide, análisis cinemático, mecanismo de cuatro barras. I. INTRODUCCIÓNUn robot humanoide es un sistema mecatrónico de alta complejidad cuya funcionalidad sólo puede alcanzarse por la interacción de los componentes mecánicos, sensores, actuadores, software y demás tecnologías que lo componen [1]. EL robot humanoide opera en un entorno hecho por y para humanos por lo tanto su objetivo es facilitar y hacer más cómoda la vida para las personas, así como realizar actividades que representen un riesgo o sean imposibles de llevar a cabo para un humano [2]. Al ser de tipo humanoide, la aceptación por parte de los usuarios es mayor debido a su aspecto familiar [3]. Actualmente existe un gran interés en los robots humanoides a diferentes escalas, este interés ha llegado a movi...