320 research outputs found

    Instantaneous Rotational Speed Measurement Using Image Correlation and Periodicity Determination Algorithms

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    Dynamic and accurate measurement of instantaneous rotational speed is desirable in many industrial processes for both condition monitoring and safety control purposes. This paper presents a novel imaging based system for instantaneous rotational speed measurement. The low-cost imaging device focuses on the side surface of a rotating shaft without the use of a marker, entailing benefits of non-contact measurement, low maintenance and wide applicability. Meanwhile, new periodicity determination methods based on the Chirp-Z transform and parabolic interpolation based auto-correlation algorithm are proposed to process the signal of similarity level reconstructed using an image correlation algorithm. Experimental investigations are conducted on a purpose-built test rig to quantify the effects of the periodicity determination algorithm, frame rate, image resolution, exposure time, illumination conditions, and photographic angle on the accuracy and reliability of the measurement system. Experimental results under steady and transient operating conditions demonstrate that the system is capable of providing measurements of a constant or gradually varying speed with a relative error no greater than ±0.6% over a speed range from 100 to 3000 RPM (Revolutions Per Minute). Under step change conditions the proposed system can achieve valid speed measurement with a maximum error of 1.4%

    Instantaneous Rotational Speed Measurement of Wind Turbine Blades using a Marker-Tracking Method

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    Rotational speed of wind turbine blades is an important parameter reflecting the operating and structural health conditions of wind turbines. Traditionally, the rotor speed is measured using inertial measuring units (IMUs). The biggest issue with IMUs is that the measurements drift over time and require constant calibration. This paper presents a direct way of measuring the instantaneous rotational speed of wind turbine blades using a camera and a marker-tracking method. The proposed measurement method is assessed by conducting a series of simulation experiments under different conditions – fixed speed, stepped varying speed, and linear varying speed. Results demonstrate that when using a camera with a frame rate of 30 fps (frames per second), the marker-tracking method yields a relative error within ±0.5% at the speed between 5 to 30 rpm (revolutions per minute). Compared to the image-correlation method, the marker-tracking method provides better results in terms of accuracy and reaction time, especially under varying speed conditions

    Data Acquisition System Using AT89c51 and PCL-207

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    A typical data acquisition system consists of individual sensors with necessary signalconditioning, data conversion, data processing, multiplexing, data handling and associated transmission, storage and display system. In order to optimize the characteristics of a system in terms of performance, handling capacity and cost, the relevant subsystem can be combined together. Analog data is generally acquired and converted into the digital form for the purpose of processing, transmission and display. Rapid advances in Personal Computer (PC) hardware and software technologies have resulted in easy and efficient adoption of PCs in various precise measurement and complex control applications. A PC based measurement or control application requires conversion of real world analog signal into digital format and transfer of digitized data into the PC. A data acquisition system that performs conversion of analog signal to digital data and the digital data to analog signal is interfaced to a pc to implement the functions of a measurement and control instrumentation applications. In this project we have used the electromagnetic sensor to acquire the data of a magnetic disk angular velocity, which we have got in mili volts range. This has been further converted approximately into the range of 5 volt by using an instrumentation amplifier of suitable gain (~20).We then converted the analog voltage into digital by using ADC 0808 and the processing part is done by using ATMEL89c51.In the second case we have used the data acquisition card PCL-207 to interface the amplified output to PC

    Intelligent Ground Vehicle Competition

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    The Intelligent Ground Vehicle Competition (IGVC) draws teams from various universities to compete in the annual autonomous vehicle challenge at the Oakland University campus. To compete, a vehicle must be fully autonomous and can navigate a course designated by various obstacles and painted white lines. Some design challenges are motor control, navigation, environment sensing and safety. A complex navigation system will utilize several tools including a high-precision differential GPS. The vehicle’s surroundings will be mapped using a combination of Light Detection and Ranging (LiDAR) and computer-vision enabled imaging. To comply with IGVC rules, the vehicle must also follow several safety requirements such as physical and wireless emergency stop, safety lighting, and the ability to assume manual control. By fulfilling these design challenges, the design team is seeking to compete in the 2017 Intelligent Ground Vehicle Competition

    A low power engine test stand

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    The engine test stand is a set of systems needed to identify, map, or optimize an engine. The complex task of the integration of those system requires many areas of expertise. This work tries to tackle that, aiming on three main points. One is provide a list of the set of transducers and measurements needed to test an engine. Second is to provide basic knowledge of the techniques needed to put to practice to achieve a data acquisition. And third the development of a dynamometer controller based on renewable energies, to be more precise, on wind energy harvesting. To conclude this work a transient analysis of the controller is listed.O banco de ensaios de motores alternativos é constituído por um conjunto de sistemas necessários para efetuar identificação, mapeamento ou otimização de um dado motor. A integração dos vários sistemas requer um vasto conjunto disciplinas. Este trabalho, tenta resolver isto, apontando para três pontos importantes do banco de ensaios. Um é listar os vários sensores e medições necessárias para testar um motor. Segundo é prever o conhecimento básico das técnicas necessárias para por em prática um sistema de adquisição de dados. Terceiro é desenvolver um dinamómetro baseado em energias renováveis, mais precisamente, energia eólica. Para concluir este trabalho é efetuada ao controlador uma análise de transição

    PC-Based Data Acquisition using PCL-208

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    DAQ (Data AcQuisition) is simply the process of bringing a real-world signal, such as avoltage, into the computer, for processing, analysis, storage or other data manipulation. A Physical phenomena represents the real-world signal you are trying to measure. In order to optimize the characteristics of a system in terms of performance, handling capacity and cost, the relevant subsystem can be combined together. Analog data is generally acquired and transformed into the digital form for the purpose of processing, transmission and display. Rapid advances in Personal Computer (PC) hardware and software technologies have resulted in easy and efficient adoption of PCs in various precise measurement and complex control applications. A PC based measurement or control application requires conversion of real world analog signal into digital format and transfer of digitized data into the PC. A data acquisition system that performs conversion of analog signal to digital data and the digital data to analog signal is interfaced to a pc to implement the functions of a measurement and control instrumentation applications. In this project we have used the electromagnetic sensor to acquire the data of a magnetic disk angular velocity, which we have got in mili volts range. This has been further transformed approximately into the range of 5 volt by using an operational amplifier of suitable gain (~30)and then rectified .We then transformed the analog voltage into digital by using ADC 0804 and the processing part is done by using ATMEL89c51.In the second phase we have used the data acquisition card PCL-208 and 207 to interface the amplified output to PC by the help TURBO C (C compiler)

    A Low-Cost Non-Intrusive Method for In-Field Motor Speed Measurement Based on a Smartphone

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    Induction motors are broadly used as drivers of a large variety of industrial equipment. A proper measurement of the motor rotation speed is essential to monitor the performance of most industrial drives. As an example, the measurement of rotor speed is a simple and broadly used industrial method to estimate the motor’s efficiency or mechanical load. In this work, a new low-cost non-intrusive method for in-field motor speed measurement, based on the spectral analysis of the motor audible noise, is proposed. The motor noise is acquired using a smartphone and processed by a MATLAB-based routine, which determines the rotation speed by identifying the rotor shaft mechanical frequency from the harmonic spectrum of the noise signal. This work intends to test the hypothesis that the emitted motor noise, like mechanical vibrations, contains a frequency component due to the rotation speed which, to the authors’ knowledge, has thus far been disregarded for the purpose of speed measurement. The experimental results of a variety of tests, from no load to full load, including the use of a frequency converter, found that relative errors on the speed estimation were always lower than 0.151%. These findings proved the versatility, robustness, and accuracy of the proposed method.Spanish MEC-Ministerio de Economía y Competitividad (Ministry of Economy and Competitiveness), co-funded by the European Commission (ERDF-European Regional Development Fund) ENE2016-77650-RMinisterio de Ciencia e Innovación (España) CERVERA research program of CDTI (Industrial and Technological Development Centre of Spain) research Project HySGrid+ CER-2019101

    Present status of aircraft instruments

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    This report gives a brief description of the present state of development and of the performance characteristics of instruments included in the following group: speed instruments, altitude instruments, navigation instruments, power-plant instruments, oxygen instruments, instruments for aerial photography, fog-flying instruments, general problems, summary of instrument and research problems. The items considered under performance include sensitivity, scale errors, effects of temperature and pressure, effects of acceleration and vibration, time lag, damping, leaks, elastic defects, and friction

    The development and analysis of a system to measure transient angular velocity

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    A measuring system was built to provide a D. C. voltage which was proportional to the angular speed of a particular rotating shaft under question. The measuring system developed has a time constant of approximately .00365 seconds. The final measuring system was developed after trying various other means which proved unsatisfactory. The final device developed would be quite satisfactory in a wide variety of applications --Abstract, page ii
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