Tracking and modeling the movement of Queensland fruit flies, Bactrocera tryoni, using harmonic radar in papaya fields.

Determining movement parameters for pest insects such as tephritid fruit flies is critical to developing models which can be used to increase the effectiveness of surveillance and control strategies. In this study, harmonic radar was used to track wild-caught male Queensland fruit flies (Qflies), Bactrocera tryoni, in papaya fields. Experiment 1 continuously tracked single flies which were prodded to induce movement. Qfly movements from this experiment showed greater mean squared displacement than predicted by both a simple random walk (RW) or a correlated random walk (CRW) model, suggesting that movement parameters derived from the entire data set do not adequately describe the movement of individual Qfly at all spatial scales or for all behavioral states. This conclusion is supported by both fractal and hidden Markov model (HMM) analysis. Lower fractal dimensions (straighter movement paths) were observed at larger spatial scales (> 2.5 m) suggesting that Qflies have qualitatively distinct movement at different scales. Further, a two-state HMM fit the observed movement data better than the CRW or RW models. Experiment 2 identified individual landing locations, twice a day, for groups of released Qflies, demonstrating that flies could be tracked over longer periods of time.

Co-simulación del Diseño Biomecánico para un Exoesqueleto Robótico del Miembro Inferior / Co-simulation of Biomechanical Design for a Robotic Exoskeleton for the Lower Limb

Este trabajo muestra como la co-simulación incrementa las ventajas y decrementa las desventajas para el diseño del exoesqueleto. La metodología propuesta tiene tres estados: el diseño de la parte biomecánica, el diseño mecánico y el sistema de control Para el análisis biomecánico, OpenSim® resuelve el sistema musculo-esquelético e incluye modelos para diferentes condiciones que pueden ser usados en el diseño de procesos. SolidWorks® que es aplicado en diseños asistidos por computadora evalúa la parte mecánica y Matlab® resuelve el sistema de control del exoesqueleto. Esto permite conseguir un diseño personalizado, que simula los movimientos de una marcha completa cubriendo las restricciones cinemáticas para lograr un movimiento natural y las limitaciones del usuario cuando tienen algún problema para caminar. El resultado muestra como es aplicada la co-simulación para hacer un prototipo virtual, como se unen y dependen los programas uno del otro. Aunque la simulación convencional de cada programa puede ahorrar dinero y tiempo, estos no resuelven completamente los problemas de diseño del exoesqueleto; por lo tanto la co-simulación es una excelente opción para la biomecánica, la mecánica y los sistemas de control que necesitan exactitud y rapidez en cada parte del proceso de diseño.

This work shows how the co-simulation increases the advantages and decreases the drawbacks for exoskeleton design. The proposed methodology has three stages: the design of a biomechanical part, the mechanical design and the control system. For the biomechanical analysis, OpenSim ® solves the muscle-skeleton system and includes models for different conditions that can be used in the design process. SolidWorks® that is applied in assistive computer design evaluates the mechanical part of the exoskeleton and Matlab® solves the control system that takes over the exoskeleton. It allows getting a personalized design which simulates the complete walking movements, covering the kinematic restrictions to achieve a natural human movement and the user limitations when they have any problem for to walk. The results show how the co-simulation is applied to complete a virtual prototype and the programs are linked hand in hand. Although conventional simulation by one program can save money and time, it cannot solve the entire exoskeleton design problem; as a result the co-simulation is an excellent option in biomechanical, mechanical and control systems that need accurate and swift results in each part of the design process.