Robot guidance using machine vision techniques in industrial environments: A comparative review

In the factory of the future, most of the operations will be done by autonomous robots that need visual feedback to move around the working space avoiding obstacles, to work collaboratively with humans, to identify and locate the working parts, to complete the information provided by other sensors to improve their positioning accuracy, etc. Different vision techniques, such as photogrammetry, stereo vision, structured light, time of flight and laser triangulation, among others, are widely used for inspection and quality control processes in the industry and now for robot guidance. Choosing which type of vision system to use is highly dependent on the parts that need to be located or measured. Thus, in this paper a comparative review of different machine vision techniques for robot guidance is presented. This work analyzes accuracy, range and weight of the sensors, safety, processing time and environmental influences. Researchers and developers can take it as a background information for their future works

Quantitative thermal imaging using single-pixel Si APD and MEMS mirror

Accurate quantitative temperature measurements are difficult to achieve using focal-plane array sensors. This is due to reflections inside the instrument and the difficulty of calibrating a matrix of pixels as identical radiation thermometers. Size-of-source effect (SSE), which is the dependence of an infrared temperature measurement on the area surrounding the target area, is a major contributor to this problem and cannot be reduced using glare stops. Measurements are affected by power received from outside the field-of-view (FOV), leading to increased measurement uncertainty. In this work, we present a micromechanical systems (MEMS) mirror based scanning thermal imaging camera with reduced measurement uncertainty compared to focal-plane array based systems. We demonstrate our flexible imaging approach using a Si avalanche photodiode (APD), which utilises high internal gain to enable the measurement of lower target temperatures with an effective wavelength of 1 µm and compare results with a Si photodiode. We compare measurements from our APD thermal imaging instrument against a commercial bolometer based focal-plane array camera. Our scanning approach results in a reduction in SSE related temperature error by 66 °C for the measurement of a spatially uniform 800 °C target when the target aperture diameter is increased from 10 to 20 mm. We also find that our APD instrument is capable of measuring target temperatures below 700 °C, over these near infrared wavelengths, with D* related measurement uncertainty of ± 0.5 °C

Auditoría informática del desarrollo de aplicaciones

Este trabajo pretende continuar con la auditoría llevada a cabo el pasado año, de los trabajos realizados para la asignatura de “Ingeniería del Software” de 3°. En el nuevo estudio realizado son auditados todos los proyectos entregados por los alumnos de 4° curso de la Escuela Técnica Superior de Ingenieros Industriales e Ingenieros Informáticos para la asignatura de Ingeniería del Software I, en un ámbito de desarrollo más similar al de una organización de desarrollo. Los proyectos son realizados por equipos formados por alumnos, los cuales tienen por usuarios y equipos de aseguramiento de calidad a distintos alumnos de “Ingeniería del Software II” (de 5° curso). Los directores de los proyectos son los profesores responsables de las asignaturas. Para el desarrollo del ciclo de vida de los proyectos software, se sigue un Manual de Procedimientos que define el proceso de desarrollo y adapta la metodología Métrica Versión 2.1 al entorno en que se realizan los proyectos

A profile measurement system for rail quality assessment during manufacturing

Steel rails used in the transport sector and in industry are designed and manufactured to support high stress levels generated by high-speed and heavy-loaded modern trains. In the rail manufacturing process, one of the key stages is rolling, where fast, accurate and repeatable rail profile measurement is a major challenge. In this paper, a rail profile measurement system for rail rolling mills based on four conventional, inexpensive laser range finders is proposed. The range finders are calibrated using a common reference to properly express the point clouds generated by each range finder in the world coordinate system. The alignment of the point clouds to the rail model is performed by means of an efficient and robust registration method. Experiments carried out in a rail rolling mill demonstrate the accuracy and repeatability of the system; the maximum error is below 0.12%. All parallelizable tasks were designed and developed to be executed concurrently, achieving an acquisition rate of up to 210 fp

Infrared Thermography for Temperature Measurement and Non-Destructive Testing

The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed

Evaluation of High Resolution Thermal Imaging to Determine the Effect of Vertebral Fractures on Associated Skin Surface Temperature in Children with Osteogenesis Imperfecta

Vertebral fractures are common in children with osteogenesis imperfecta (OI). Current imaging methods for fracture detection (X-ray and DXA) use ionising radiation. This pilot study explored whether the alteration in blood flow in vertebral fractures results in skin temperature changes that may be detected using high resolution thermal imaging (HRTI) and thus assist diagnosis and monitoring of fractures in OI patients. Eleven participants aged 5-18 years with OI and known vertebral fractures were enrolled. Small metal discs were placed on the skin surface alongside the vertebrae before participants had DXA and X-ray scans and thermal imaging of their backs. Visibility of the discs on the DXA and X-ray scans and thermal images allowed the temperatures of the skin surface above vertebrae without (healthy) and with fractures to be compared to their respective adjacent skin surface regions (Region of Reference, ROR) by calculating the temperature percentage change (TPC). The TPC between the skin temperature over the fractured thoracic vertebrae (n=11) and the ROR was significant (1.44%, p=0.002, 95% confidence). TPC between the skin temperature over healthy thoracic vertebrae and ROR was not (0.97%, p=0.15, 95% confidence). HRTI may provide a novel tool for assisting in detection of vertebral fractures in OI. Keywords: Computerised medical diagnosis, thermal imaging, vertebral fracture detection, osteogenesis imperfecta

Design and realization of a wide field of view infrared scanning system with an integrated micro-electromechanical system mirror

We present a wide field of view (FOV) infrared scanning system, designed for single-pixel near-infrared thermal imaging. The scanning system consisted of a two-axis micro-electromechanical system (MEMS) mirror that was incorporated within the lens. The optical system consisted of two groups of lenses and a silicon avalanche photodiode. The system was designed for both the production of thermal images and also to utilize the techniques of radiation thermometry to measure the absolute temperature of targets from 500°C to 1100°C. Our system has the potential for real-time image acquisition, with improved data acquisition electronics. The FOV of our scanning system was ±30° when fully utilizing the MEMS mirror’s scanning angle of ±5°. The pixel FOV (calculated from the distance to target size ratio) was 100:1. The image quality was analyzed, including the modulation transfer function, spot diagrams, ray fan plots, lateral chromatic aberrations, distortion, relative illumination, and size-of-source effect. The instrument was fabricated in our laboratory, and one of the thermal images, which was taken with the new lens, is presented as an example of the instrument optical performance