This paper presents a source localization algorithm based on the signal's time-difference-of-arrival (TDOA) for asynchronous wireless sensor network. To obtain synchronization among anchors, all anchors broadcast signals periodically, clock offsets and skews of anchor pairs can be estimated using broadcasting time-of-arrivals (TOA) at anchors. A kalman filter is adopted to improve accuracy track drifts due random fluctuations. Once transmits signal, TOAs are stamped respectively source's...

For unmanned aerial vehicle (UAV)-based smart inspection in extremely confined environments, it is impossible for precise UAV positioning with global system, owing to the satellite signal block. Therefore, ultrawideband (UWB)-based technology has attracted extensive attention under such circumstances. However, due unpredictable propagation condition and time-varying operational environment, localization performance oscillation caused by changing measurement noise may lead instability of UAV....

This paper presents a tag localization algorithm based on the time-difference-of-arrival (TDOA) of mobile signal for asynchronous wireless sensor network (WSN) with N anchors (nodes known locations) and large number tags. To obtain time synchronization, all broadcast signals periodically; relative clock offsets skews anchor pairs are estimated by least-square (LS) method using times-of-arrival (TOAs) at anchors. When transmits signal, TOA each is stamped errors in original TDOAs due to...

In this paper, a high-precision ultra-wideband (UWB) based unmanned aerial vehicle (UAV) localisation approach is proposed for applications in extremely confined environments. It motivated by the emerging demand on autonomous inspection such environments that are hard or impossible humans to access. Instead of traditional techniques as global positioning system (GPS), vision other techniques, UWB technique adopted precise UAV due its high accuracy, implementation simplicity and suitability...

Unmanned Aerial Vehicles (UAVs) are becoming popular nowadays due to their versatility and flexibility for indoor applications, such as the autonomous visual inspection inner surface of a pressure vessel. Nevertheless, robust reliable position estimation is critical completing these tasks. Visual Odometry (VO) Simultaneous Localisation Mapping (VSLAM) allow UAV estimate its in unknown environments. However, traditional feature-based VO/VSLAM systems struggle deal with complex scenes low...

Abstract Monocular Visual Simultaneous Localisation and Mapping (VSLAM) systems are widely utilised for intelligent mobile robots to work in unknown environments. However, complex varying illuminations challenge the accuracy robustness of VSLAM significantly. Existing feature-based methods often fail due insufficient feature points that can be extracted those challenging illumination Therefore, this paper proposes an improved ORB-SLAM algorithm based on adaptive FAST threshold image...

Abstract Quantum technology has entered the era of noisy intermediate-scale quantum (NISQ) information processing. The technological revolution machine learning represented by generative models heralds a great prospect artificial intelligence, and huge amount data processes poses big challenge to existing computers. generation large quantities will be for intelligence. In this work, we present an efficient noise-resistant method that can applied various types NISQ processors, where target...

Investigations have been carried out on right cylindrical Teflon spacers in vacuum under dc stress to study the effect of cathode geometry surface charging and flashover. Three support arrangements were used. Type 1 involved a recess into which spacer was located, type 2 simple flat plate cathode, while 3 had raised insert over located. In all cases charge density distribution is primarily dependent upon magnitude electric stress. Using arrangement inception for deposition always /spl sim/10...

With the increasing demands for unmanned aerial vehicle (UAV)-based autonomous inspections in oil and gas industry, one of challenging issues 3-D UAV positioning has emerged due to satellite signal blocking. Considering existing characteristics ultrasonic-based technique, such as low cost, extremely lightweight, high accuracy, it can be promising potential solution. Nevertheless, position update rate vulnerable performance changing environment still limit its applications on UAV. Therefore,...

Utilising the unmanned aerial vehicle (UAV) for autonomous inspection in extremely confined environments has become a much sought research area, due to pressing industrial needs. To provide high accuracy position information of UAV such environments, ultra-wideband (UWB) based localisation technology been one ideal candidates. However, unpredictable propagation condition and geomagnetic disturbances inertial measurement unit (IMU) will all have huge impact on positioning performance with...

It is vital to visually inspect pressure vessels regularly in the oil and gas company maintain their integrity. Compared with visual inspection conducted by sending engineers ground vehicles into vessel, utilising an autonomous Unmanned Aerial Vehicle (UAV) can overcome many limitations including high labour intensity, low efficiency risk human health. This work focuses on enhancing some existing technologies support low-cost UAV navigation for of vessels. The gain ability follow planned...

Abstract With the increasing applications of unmanned aerial vehicles (UAVs) in industries, it has drawn dramatic interests that utilising UAVs for internal inspection oil tanks and vessels recent years. Due to fact there is no global positioning system (GPS) limited prior knowledge about operational environment, an unsolved problem on how get precise position information without relying knowledge. To solve this problem, a Vision Aided Self-Localisation Two-way Time Flight (VASTWTOF)...