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Português do BrasilProjects
A set of inertial sensors mounted on a unit is called an Inertial Measurement Unit (IMU). An IMU with six degrees of freedom is composed of a triad of accelerometers with mutually orthogonal sensitive axes and a triad of gyroscopes also with mutually orthogonal axes. Mathematical integration of inertial signals (acceleration and angular velocity) over time allows to track position and orientation of the IMU in a reference coordinated system.
Features such as reduced size and weight, affordable cost, low energy consumption and no need for line of sight between the measurement system and the object to be tracked make IMUs a technology with high potential for application in dimensional metrology. However, this potential is not yet consolidated, due to limitations such as the presence of noise and instability of signals due to temperature variation. In addition, mathematical processing adds other sources of error to the measurement result.
This project aims to explore the capacity of MEMS-type IMUs in dimensional metrology tasks within the scope of industrial geodesy. More specifically, given an IMU device, a measurement task and a processing algorithm, it is intended to answer the question: is the system able to perform the measurement according to the tolerance specifications? The scope of the research is limited to MEMS-type IMUs with six degrees of freedom.
Status: Finished
Modern three-dimensional measurement techniques can be important allies in reducing rework efforts in the production of ships and offshore equipment. Among the most recently developed techniques is the Indoor-GPS system (iGPS).
This system is composed of a set of infrared light signal transmitters and respective receivers. The position of the receivers in the measurement area is determined by processing the signals perceived by each of the receivers. The transmitters can be flexibly distributed around the measurement object. The measurement area covered by the system depends on the number of transmitters used. The configuration available for this project has 6 transmitters capable of covering a rectangular area of 30 m x 45 m. The maximum permissible error for length measurements under laboratory conditions is of the order of 0.2 mm, this value being constant throughout the measurement area.
The equipment manufacturer cites the naval and offshore industry as one of the application areas of this system. The possibilities of using iGPS in this sector have, however, been little explored.
This project aims to determine the performance of the iGPS system in measurement, positioning and alignment tasks in the naval and offshore industry. This objective will be achieved through: A) Identification of critical processes with potential application of the iGPS system; B) Determination of the metrological performance of the iGPS system in simulated measurement, positioning and alignment tasks on a small scale; C) Evaluation of the robustness of the system for use in a shipbuilding environment; D) Pilot application, on site, in at least one of the identified critical processes.
Improvements in shipbuilding processes through the use of advanced industrial geodesy techniques
Status: Finished
Modern three-dimensional measurement techniques in the area of metrology called industrial geodesy can be important allies in reducing rework efforts in shipbuilding and oceanic processes. Among the most recently developed techniques are the Indoor-GPS system (iGPS) and MEMS inertial systems. The iGPS system is composed of a set of infrared light signal transmitters and respective receivers. The position of the receivers in the measurement area is determined by processing the signals received by each of the receivers. The transmitters can be flexibly distributed around the measurement object. The measurement area covered by the system depends on the number of transmitters used. The configuration available for this project has 6 transmitters capable of covering a rectangular area of 30 m x 45 m. The maximum permissible error for length measurements under laboratory conditions is of the order of 0.2 mm, this value being constant throughout the measurement area. The equipment manufacturer cites the naval and oceanic industry as one of the application areas of this system. The possibilities of using iGPS in this sector have, however, been little explored.
Another alternative to conventional systems (total station, levels, plumbs etc.) for the alignment and positioning steps of blocks and megablocks represent position and orientation measurement systems based on MEMS-type miniaturized inertial sensors. These low-cost systems, typically composed of triads of accelerometers and gyroscopes, are now, for example, used in high-end smartphones (e.g. Apple iPhone 5 and Samsung S4) and electronic games (e.g. Nintendo Wii). Although widely used in areas with high requirements for precision and accuracy, such as robotics and autonomous vehicles, no references were found in the literature related to the use of this type of system to support assembly processes in shipbuilding.
This project aims to improve the quality and productivity of panel assembly, block assembly and final assembly processes in the construction of vessels and oceanic structures through the use of advanced industrial geodesy techniques. This general objective is deployed in the following specific goals: A) evaluation of the metrological performance of the sensors of an inertial MEMS system; B) development of a system based on inertial MEMS systems for tracking an object in space in six degrees of freedom; C) development of physical models on a reduced scale of components for simulation of panel assembly, block assembly and building processes; D) process development at scale (e.g. 1: 5) using iGPS technologies and inertial MEMS systems; E) experimental evaluation of the performance of the miniaturized assembly processes and F) pilot application, on site, of at least one of the assembly processes developed.