Remote Ultrasonic Pipeline Monitoring System - Report Example

REMOTE ULTRASONIC PIPELINE MONITORING SYSTEM Introduction The Remote Ultrasonic Gas and Oil Pipeline Monitoring System (the RUGOPMS) accurately measures the amount of gas or oil flowing via the pipe and then sends data to a PC through remote or wireless transmission. By utilizing a transit time flow measurement, the oil or gas flow rate is calculated by applying the ultrasonic beam’s time transmission and its arrival time at the ultrasonic transducers. Measurement of the upstream and downstream transit times for the transducers triggers the RUGOPMS’ measurement of the oil and gas within the pipe. The flows that below a set threshold flow rate for the system, an alarm sound is send to notify users on oil or gas leakages detected within the supply pipe. System Requirements The RUGOPMS’ system requirements are presented below: Figure 1. RUGOPMS System Block Diagram The RUGOPMS measures the rate of oil or gas flow in the pipe under the ultrasonic Transit-time methodology. Regular transit-time flow meter works on the time difference emanating from the ultrasonic waves time period utilized in travelling between the transducers. The material flow measuring is achieved via the release of the ultrasound waves in the opposite and same direction of the fluid flow and recording the time difference emanating from the directions. Processing of the signals is achieved by the Arduino Uno microcontroller. When the analysis stage is complete, the data is transmitted to the receiver and then displayed on the display units or the users’ computers. The data output is presented either in graphs forms or figures form. The data obtained can be stored in memory, or analyzed, or be utilized in further usages, for example, pipe ruptures and leakage detection. In any case of leakage, users are informed appropriately; and ruptures are detected via alarm and users are informed of the emergency. Figure 2. RUGOPMS Flow Chart; X and K are design factors. The Ultra-Low Power Flow Monitoring System The Micro-Controller-Unit (MCU), Arduino Uno, in combination with power amplifier PA 85 from Apex Technology is utilized because of their high power efficiency. The Arduino Uno is a 16-bit MCU that has high-speed, compact dimensions, wide address space, low-power operations, and single main command single-clock execution with the gate-saving design. The RUGOPMS provides the following: instantaneous and integrated flow recording, low battery voltage detections and the pulse outputs for telemetering devices. Sensors are connected directly to the MCU’s comparators in order to reduce power losses. Ultrasound Methodology Ultrasonic implies the sound waves or motions that vibrate rapidly, beyond the human ear range of 20 Hz to 20 KHz; the ultrasonic waves incorporate frequencies beyond 20 kHz. The ultrasonic waves are similar to audible sound, for example, they require medium for travelling; however, they are short in terms of wavelength. The ultrasonic transducers are utilized in converting the electrical energy into mechanical energy, usually similar to sound; the piezoelectric converters are mostly used as ultrasonic wave’s generators. Acoustic Parameter Definitions Peak Frequency The highest frequency response obtained from frequency spectrum Sensitivity (S) The S (dB) is equivalent to -20logVx/Vo with Vo representing the excitation pulse,; usually in volts. The Vx represents the received signal, volts. The sensitivity measure is also known as loop gain or loop sensitivity; it is dependent on the medium performed in. Nominal frequency (F) Obtained from the transducer housing Bandwidth (BW) Difference the lowest and highest frequencies at the -6dB level. Signal to Noise Ratio (the SNR) The SNR (dB) is equivalent to -20logVx/Vo with Vo representing the noise floor,; usually in volts. The Vx represents the received signal’s amplitude, volts. The sensitivity measure is also known as loop gain or loop sensitivity; it is dependent on the medium performed in. Table 1. The acoustic parameters for the ultrasonic transducer Figure 3. The Transit-time flow meter (Boyes, 2010) The time that is used when travelling from one sensor to another is varied since the fluid is flowing via the pipe. The flow velocity is obtained from the measurement of flow time differences as follows: tR = tF = From the equation, tF represents time taken by sound in travelling to the second sensor; tR represents time required by the sound in order to be received at the sensor. V is the fluid velocity; c is the sound’s velocity; represents an angle between the axis and beam of fluid flow; and L represent distance between the ultrasonic receiver and transmitter (De Silva, 2007). The time difference or T is obtained as follows: tF - tR ==T When the receipt pulse is utilized in the triggering of the transmitter in order to result into the sound beams; then, the frequency of the return and forward pulses are formulated as below: tR = tF = Hence f= tF - tR = therefore V= Figure 4. The circuit for generating trains in both forward and return pulse An LM555 timer is utilized in the driving of the ultrasonic traducer with approximately 40 kHz sine pulse. An ultrasonic transducer is then connected to the 555 timer circuit as a speaker element; the transducer’s signals are amplified after the connection to the timer. The capacitors and resistors of the transducer are tuned in order to produce 40 kHz sine pulse with the timer. The 555 timer operates in in the astable mode by producing continuous sine pulses, in one of its out pins, to reset one of its held high pin. If the held high pin is at 0V, the sine pulse trains are halted and hence the 555 timer’s output cannot produce the sine pulse. An amplifier PA 85 is placed after the timer for the amplification of the voltage output signal emanating from the 555 timer. Approximately 2.5V and 40 kHz sine pulse is produced and fed to the Arduino Uno from the timer 555; the reason of using an analog circuit, that is the timer, is to drive an ultrasonic transducer in order to generate or transmit a 40 kHz sine pulse by reducing the workload on the MCU. Moreover, the elimination of dependency on the production of the sine wave from the MCU enable the processor’s spare cycles or the Arduino Uno’s spare timer to be utilized in calculating, reading data, writing data and remote transmission handling. Receiver Circuit The receiver circuit is utilized in receiving or picking the ultrasonic signal from air. The sine signal is generated or produced by the matched ultrasonic transmitter. The receiver’s circuit is capable of vibrating optimally at approximately 40 kHz. Hence a 40 kHz sine signal can be relayed or transmitted from the transmitting circuit. The receiver is capable of generating electric pulse when detecting the 40 kHz input. The received electric signals are then amplified in the circuit, eventually the amplified outputs are fed into the phase-locked loop (the PLL) decoder. The PLL is the decoder that is able to generate or produce an output when it detects the input sine signals at 40 kHz; the PLL is set at 40 kHz as the set frequency. The output emanating from the PLL decoder goes to the microcontroller. A capacitor is used for reason of filtering signal noise when the signal enters the decoder (Webster and Eren, 2014). A PLL circuit for frequency and tone decoding with high stable phase-locked loop integrating the synchronous Amplitude Modulation (AM) lock detection with the power output circuitry should be used. This is because the circuit will be able to perform its primary functions by driving the load when the sustained frequency at the detection band is availed at the self-biased inputs. The output delay and bandwidth centre frequency are independently determined through external components. The PLL decoder is characterised by the high stability of its centre frequency and possess the high out-band signal and the noise rejection. The above features are vital to remote communications; since the feature reduce interferences. The PLL tone decoder output is filtered for cleaner signal from the PLL’s output into the MCU for easy and accurate detection of the signal in sine wave. Conclusion The design specifications have the solution to RUGOPMS function specification. The proposed components and methodology are chosen in meeting the requirements for project. Moreover, the safety and stability is within the consideration and is ensured. The RUGOPMS design purpose is expected to be met in the real environment. References Boyes, W. (2010). Instrumentation reference book. Amsterdam: Butterworth-Heinemann/Elsevier. De Silva, C. (2007). Sensors and actuators. Boca Raton : CRC Press. Webster, J. and Eren, H. (2014). Measurement, Instrumentation, and Sensors Handbook, Second Edition. Hoboken: Taylor and Francis. Read More