875 research outputs found

    Navigation for automatic guided vehicles using omnidirectional optical sensing

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    Thesis (M. Tech. (Engineering: Electrical)) -- Central University of technology, Free State, 2013Automatic Guided Vehicles (AGVs) are being used more frequently in a manufacturing environment. These AGVs are navigated in many different ways, utilising multiple types of sensors for detecting the environment like distance, obstacles, and a set route. Different algorithms or methods are then used to utilise this environmental information for navigation purposes applied onto the AGV for control purposes. Developing a platform that could be easily reconfigured in alternative route applications utilising vision was one of the aims of the research. In this research such sensors detecting the environment was replaced and/or minimised by the use of a single, omnidirectional Webcam picture stream utilising an own developed mirror and Perspex tube setup. The area of interest in each frame was extracted saving on computational recourses and time. By utilising image processing, the vehicle was navigated on a predetermined route. Different edge detection methods and segmentation methods were investigated on this vision signal for route and sign navigation. Prewitt edge detection was eventually implemented, Hough transfers used for border detection and Kalman filtering for minimising border detected noise for staying on the navigated route. Reconfigurability was added to the route layout by coloured signs incorporated in the navigation process. The result was the manipulation of a number of AGV’s, each on its own designated coloured signed route. This route could be reconfigured by the operator with no programming alteration or intervention. The YCbCr colour space signal was implemented in detecting specific control signs for alternative colour route navigation. The result was used generating commands to control the AGV through serial commands sent on a laptop’s Universal Serial Bus (USB) port with a PIC microcontroller interface board controlling the motors by means of pulse width modulation (PWM). A total MATLAB® software development platform was utilised by implementing written M-files, Simulink® models, masked function blocks and .mat files for sourcing the workspace variables and generating executable files. This continuous development system lends itself to speedy evaluation and implementation of image processing options on the AGV. All the work done in the thesis was validated by simulations using actual data and by physical experimentation

    Hardware design for in-mine positioning system

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    This thesis describes the hardware design of a positioning system which locates a vehicle relative to a digital map of an underground mine. The mines of interest are potash mines of Saskatchewan, and they are at a depth of approximately 1000 meters and they cover an area larger than 10 kilometers by 10 kilometers. An important application of an in-mine positioning system is tracking a ground penetrating radar system. Ground penetrating radar is used to determine the current condition of the mine ceiling and to evaluate its risk of delamination. A ground penetrating radar system is driven along a mine tunnel and measurements are logged. It is necessary to record position information along with the radar signal and this can be done with the aid of a positioning system. The design and evaluation of the hardware system that supports a positioning system, which can locate a vehicle inside a mine tunnel with reasonable accuracy and cost is described in this thesis. The hardware system includes a dead reckoning system (DRS), which is built using MEMS (Micro Electro Mechanical System) accelerometer and gyroscope sensors and ultrasonic distance sensors, along with a data acquisition system

    Smartphone relative positioning using phone sensors

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    Rationale Document: Entity Information And Entity Interaction In A Distributed Interactive Simulation

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    Report on efforts to define and develop a standard communication protocol at the protocol data unit level
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