Locating the source of a radio wave signal is an essential research topic in various applications, such as tracking systems, navigation systems, and systems related to safety and security. This research has studied an...
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Locating the source of a radio wave signal is an essential research topic in various applications, such as tracking systems, navigation systems, and systems related to safety and security. This research has studied and analyzed the effect of sensor device positioning on the efficiency in determining the source's location based on Time Difference of Arrival (tdoa) technology. We focused on the system's efficiency in areas where sensors cannot be installed. The results and analysis demonstrate that the configuration pattern of the sensor device instantly influences the dimensions and coverage area at which the radiation source can be accurately detected. This research furnishes an essential basis for further developing and deploying transmitter detection approaches, particularly in inaccessible places.
To resolve the measured target position to determine and locate leak problems with current gas leak detection and localization systems based on ultrasonic technology, this paper presents an improved multi-array ultras...
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To resolve the measured target position to determine and locate leak problems with current gas leak detection and localization systems based on ultrasonic technology, this paper presents an improved multi-array ultrasonic gas leak tdoa (time difference of arrival) localization and detection method. This method involves arranging ultrasonic transducers at equal intervals in a high-sensitivity detector array, using small differences in ultrasonic sound intensity to determine the scope of the leak and generate a rough localization, and then using an array tdoa localization algorithm to determine the precise leak location. This method is then implemented in an ultrasonic leak detection and localization system. Experimental results showed that the tdoa localization method, using auxiliary sound intensity factors to avoid dependence on a single sound intensity to determine the leak size and location, achieved a localization error of less than 2 mm. The validity and correctness of this approach were thus verified.
Aiming at the problems of non-line-of-sight delay and low positioning accuracy in the location of transport vehicles in the complex environment of the non-coal opencast mine, an improved adaptive H infinity CKF and IA...
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Aiming at the problems of non-line-of-sight delay and low positioning accuracy in the location of transport vehicles in the complex environment of the non-coal opencast mine, an improved adaptive H infinity CKF and IAGA-tdoa positioning algorithm for transport vehicles in non-coal opencast mine is proposed, a Lora + 4G positioning platform is built, and the effectiveness of the algorithm is verified through simulation and field test. Improved Adaptive Genetic algorithm (IAGA) updates the optimal preservation strategy of traditional genetic algorithm and redefines the adaptive cross rate and variation rate. The improved adaptive H infinity Cubature Kalman Filter (CKF) algorithm reduces the effect of noise by weighting new and old noise. The simulation results show that the relative error of the improved adaptive H infinity CKF algorithm is reduced by 85% compared with the traditional Kalman Filter. Comparing IAGA with other four algorithms to solve the tdoa positioning model, the IAGA algorithm has the smallest positioning error, and the minimum error is only 0.8 m. The field test shows that the average error of the system is within 7.4 m, and it can display the historical running track of the vehicle, which has a certain guiding significance for the automatic production of the mining area.
Time-based ultra-wideband (UWB) indoor localisation system is affected by clock offset, electromagnetic interference, NLOS and other external conditions, the localisation accuracy and stability will be greatly reduced...
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Time-based ultra-wideband (UWB) indoor localisation system is affected by clock offset, electromagnetic interference, NLOS and other external conditions, the localisation accuracy and stability will be greatly reduced. Differential GPS (DGPS) technology introduces a reference station, which transmits a pseudo range correction value to a GPS receiver for error correction, thereby largely reducing the localisation error to improve GPS localisation accuracy and localisation stability. In this paper a differential UWB localisation algorithm combined with weighted moving average is proposed by drawing on the experiences of differential GPS, focusing on clock offsets and propagation effects. At the same time, the differential UWB indoor localisation system based on tdoa algorithm is tested by Hainan EVK 2.0 experiments. The experiment results show that Differential UWB indoor localisation system can effectively improve the localisation precision and localisation stability, especially in the case of external disturbances, the overall localisation error is reduced by 23%.
The intra-pulse phase change caused by frequency difference of arrival (FDOA) is very little and even omitted due to extremely short duration of emitter pulses that the joint location using time difference of arrival ...
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The intra-pulse phase change caused by frequency difference of arrival (FDOA) is very little and even omitted due to extremely short duration of emitter pulses that the joint location using time difference of arrival (tdoa) and FDOA cannot be realised. To solve this problem, a multi-pulse coherent accumulation algorithm of direct position determination (DPD) using the tdoa and FDOA is proposed in this study. Through establishing coherent signal model of short pulses which is deterministic but unknown, the maximum likelihood estimator for localisation of a stationary emitter using multiple moving receivers is derived by taking the DPD approach under additive Gaussian white noise environment. This study also derives a signal-specific Cramer-Rao lower bound (CRLB) of DPD, modelling the signal as a deterministic unknown. The CRLB is more applicable to some specific (non-stationary, non-Gaussian) signals, especially electromagnetic signals. Simulation results show that the proposed method achieves a significant performance improvement in locating accuracy over the existing methods and its accuracy is close to the CRLB in normal signal-to-noise ratio.
Above-ground marking systems, composed of instrumented pigs and above-ground markers (AGMs), have been widely used to locate defects in long-distance buried pipelines. However, the location error for most of the exist...
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Above-ground marking systems, composed of instrumented pigs and above-ground markers (AGMs), have been widely used to locate defects in long-distance buried pipelines. However, the location error for most of the existing AGMs can be up to several tens of centimetres. In this paper, an innovative marking method based on the girth weld impact sound is proposed. An equally-spaced four-sensor linear array was employed to collect the impact sound between the pig and the girth weld in the pipeline. A time difference of arrival (tdoa) algorithm was applied to locate the weld. Experiments show that this method can clearly locate the position of a weld relative to the linear array in buried pipelines with an error of less than 0.1 m. It is envisioned that the method has great potential to monitor the safe operations of long-range buried pipelines.
This paper proposes an ultrasonic localization system, which adopts ultrasonic sensors to set up a network and realizes the information interactively with control center via 485 Bus. Using tdoa algorithm realizes the ...
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ISBN:
(纸本)9783037852958
This paper proposes an ultrasonic localization system, which adopts ultrasonic sensors to set up a network and realizes the information interactively with control center via 485 Bus. Using tdoa algorithm realizes the localization in indoor environment, and proposes a method to gain node information, on the basis, we can get a higher degree of response speed and accuracy of the system. Take an experiment by constructing an indoor localization test terrace, to prove feasibility of the theoretical.
The wireless sensor network(WSN)has a wide range of application prospects and can be used in military,environment,sanitation,space exploration and other commercial *** for most applications,data without location infor...
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The wireless sensor network(WSN)has a wide range of application prospects and can be used in military,environment,sanitation,space exploration and other commercial *** for most applications,data without location information is not effective. Localization has become one of the indispensable supporting techniques in WSN,and has attracted worldwide *** range-based localization algorithms were compared in this *** of high positioning accuracy of tdoa algorithm and the requirement for initial values in Taylor Series Expansion,we proposed LS-Taylor algorithm and Chan-Taylor algorithm in which an available solution of initial value can be *** simulation indicates that those algorithms have a high precision as well as the Taylor *** proposed algorithms can effectively reduce repeating times and lower power loss of nodes.
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