Suitability of Unmanned Aerial Vehicles for Cadastral Surveys

Cadastral surveys in Ghana often employ well known surveying equipment such as Total Station andGNSSreceivers or a combination of both. These survey techniques are well-established and widely accepted. However, there are limitations in certain areas. In situations where difficult terrain and inaccessible areas and dense vegetation are encountered or when surveyor’s life may be at risk, Unmanned Aerial Vehicles (UAVs) could be used to overcome the limitations of these well-established survey instruments. This research used high resolution images from UAV (DJI Phantom 4) to survey plots within the University of Mines and Technology land area. Coordinates of the boundary points were extracted using Agisoft Photoscan.GNSSreceivers were also used to survey the land and the same boundary point coordinates obtained and compared. This enabled the establishment of accurate ground control points for georeferencing. The coordinates obtained from both UAV andGNSSSurveys were used to prepare cadastral plans and compared. The difference in Northings and Eastings from UAV andGNSSsurveys were +0.380 cmand +0.351 cmrespectively. These differences are well within tolerance of +/-0.9114 m(+/-3 ft) set by the Survey and Mapping Division (SMD) of the Lands Commission for cadastral plans production. This research therefore concludes that high resolution images from UAVs are suitable for cadastral surveying. Keywords: Unmanned Aerial Vehicles, Drones, Global Navigation Satellite Systems, Cadastral Survey

Model of on-line control for the smart object by communication technologies

Based on analysis of opportunities of usage existing models, methods and techniques for on-line monitoring and control of unmanned dynamic objects, a mathematical model of remote estimation of distance to wire-controlled unmanned mobile object is proposed. The presence of model and techniques of remote estimation of distance to wirecontrolled unmanned object increases the reliability of control for exclusion of critical situations in the strict radio counteraction conditions and powerful electromagnetic jamming setting during control

Model of on-line control for the smart object by communication technologies

Based on analysis of opportunities of usage existing models, methods and techniques for on-line monitoring and control of unmanned dynamic objects, a mathematical model of remote estimation of distance to wire-controlled unmanned mobile object is proposed. The presence of model and techniques of remote estimation of distance to wirecontrolled unmanned object increases the reliability of control for exclusion of critical situations in the strict radio counteraction conditions and powerful electromagnetic jamming setting during control

Visual servoing of an autonomous helicopter in urban areas using feature tracking

We present the design and implementation of a vision-based feature tracking system for an autonomous helicopter. Visual sensing is used for estimating the position and velocity of features in the image plane (urban features like windows) in order to generate velocity references for the flight control. These visual-based references are then combined with GPS-positioning references to navigate towards these features and then track them. We present results from experimental flight trials, performed in two UAV systems and under different conditions that show the feasibility and robustness of our approach

Pendaratan Presisi pada Drone Berbasis Komputer Visi

Unmanned Aerial Vehicle (UAV) atau drone adalah wahana yang tidak membutuhkan manusia untuk mengendarainya. Pesawat tampa awak sudah banyak digunakan untuk membantu pekerjaan manusia, contohnya mengantarkan paket (delivery kit), pemantauan dan pemetaan suatu area (mapping and monitoring) dan fotografi. Salah satu penelitian berlanjut adalah tentang pendaratan otomatis sebuah drone multi-copter. Metode navigasi yang berkembang saat ini yaitu sistem navigasi GPS dan sistem naviasi GPS/Visual yang terintegrasi. Dalam tugas akhir ini, komputer visi akan diaplikasikan pada sebuah drone quadcopter. Kamera akan membantu wahana untuk menemukan landasan pendaratan. Sistem visual dapat memperoleh posisi relatif wahana terhadap target. Maka dapat dirancang kontrol untuk mencapai titik pendaratan. Stabilitas dan akurasi pendaratan adalah fokus dan kesulitan yang dihadapi. Dengan pendaratan yang presisi, drone dapat diaplikasikan dengan baik pada beberapa misi seperti drone pengantar paket yang membutuhkan akurasi pendaratan yang presisi. Hasil pengujian yang didapatkan dalam tugas akhir ini adalah sistem pendaratan pada drone yang dapat mendarat dengan otomatis pada landasan yang ditentukan. Bantuan visual adalah komponen utama dalam menentukan posisi pendaratan drone. Drone berhasil mendarat dengan rata-rata error 45 cm dengan error minimum adalah 21cm. =============================================================================================================================== Unmanned Aerial Vehicle (UAV) or a drone is a vehicle that does not require humans to drive it. A plane without a crew is already widely used to help human work, for example delivering kits, monitoring and mapping an area (mapping and monitoring) and photography. One ongoing study is about the automatic landing of a multi-copter drone. The current navigation method is the GPS navigation system and integrated GPS / Visual navigation system. In this final project, computer vision will be applied to a quadcopter drone. The camera will help the vehicle to find the landing pad. The visual system can get the relative position of the vehicle towards the target. Then controls can be designed to reach the landing point. The stability and accuracy of the landing is the focus and difficulty faced. With precise landings, the drones can be applied well to several missions such as package delivery drones that require precise landing accuracy. The test results obtained in this final project are a landing system on a drone that can land automatically on a specified runway. Visual assistance is a major component in determining the position of a drone landing. The drone landed with an average error of 45 cm with the smallest error was 21cm

3D pose estimation based on planar object tracking for UAVs control

This article presents a real time Unmanned Aerial Vehicles UAVs 3D pose estimation method using planar object tracking, in order to be used on the control system of a UAV. The method explodes the rich information obtained by a projective transformation of planar objects on a calibrated camera. The algorithm obtains the metric and projective components of a reference object (landmark or helipad) with respect to the UAV camera coordinate system, using a robust real time object tracking based on homographies. The algorithm is validated on real flights that compare the estimated data against that obtained by the inertial measurement unit IMU, showing that the proposed method robustly estimates the helicopter's 3D position with respect to a reference landmark, with a high quality on the position and orientation estimation when the aircraft is flying at low altitudes, a situation in which the GPS information is often inaccurate. The obtained results indicate that the proposed algorithm is suitable for complex control tasks, such as autonomous landing, accurate low altitude positioning and dropping of payloads

Peningkatan Unjuk Kerja Sistem Sensor Garis Pemandu Pada Robot Kontes

Autonomous mobile robots competing during the Indonesian Domestic Robot Contest generally move by tracking a guidance line on the field based on information obtained from optical sensor systems. High intensity and non-homogenously distributed spotlights of television cameras have been the cause of most of the autonomous machines not to be able to move fast and accurately. As a solution, basic principles of Dual Tone Multi Frequency (DTMF) that has been successfully applied on telecommunication systems are adopted to increase the immunity of the sensor system from the disturbances. The objective of this research is to design a sensor system which is capable of detecting a guidance line as thin as 1 mm at a maximum speed of 4 m/s. The simulation results show that the system is relatively immune from 50 Hz interferences. The accuracy of the system begins to be significatly influenced by random noise on signal to noise ratio about 0 dB but the system produces an accuracy of nearly 100% for carrier frequencies above 18 kHz Index Terms— butterworth filter, contest robot, digital signal processing, microcontroller, simulation. Robot otomatis pada Kontes Robot Indonesia (KRI) umumnya bergerak mengikuti garis-garis pemandu di lapangan berdasarkan suatu sistem sensor cahaya. Pengaruh lampu sorot kamera televisi yang terlalu terang dan tidak merata menjadi permasalahan utama kegagalan mayoritas robot-robot tersebut untuk bergerak dengan kecepatan tinggi dan akurat. Sebagai solusi, prinsip kerja sistem Dual Tone Multi Frequency (DTMF) pada sistem telekomunikasi diadopsi ke dalam sistem sensor pada sistem pelacak garis robot tersebut untuk meningkatkan ketahanan sistem terhadap pengaruh cahaya luar. Penelitian ini bertujuan untuk merancang suatu sistem sensor yang mampu mendeteksi suatu garis selebar 1 mm untuk kecepatan maksimum robot sebesar 4 m/s di bawah lingkungan yang penuh derau (noise). Hasil simulasi menunjukkan bahwa sistem relatif kebal terhadap pengaruh interferensi 50 Hz. Keakuratan sistem mulai terpengaruh oleh derau acak secara signifikan pada SNR (Signal to Noise Ratio) sekitar 0 dB tetapi sistem tersebut dapat menghasilkan keakuratan mendekati 100% untuk frekuensi pembawa di atas 18 kHz. Kata Kunci— filter butterworth, mikrokontroler, pemrosesan sinyal digital, robot kontes, simulasi