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RISS 인기검색어
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- 저자 : Hamad Karki (검색결과 5 건)
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Amit Shukla,Hamad Karki 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10
This paper presents modeling, simulation, and control of a teleoperated mechanism, where two nonisomorphic devices a parallel manipulator and an under-actuated unmanned aerial vehicle (UAV) are integrated into a master-slave configuration. A Stuarts-type 6-DOF parallel manipulator is used as a master robot and a UAV is used as a slave robot. Since, the parallel manipulator has a limited task space, due to the fixed base, while the UAV has a practically unlimited workspace, direct space to space mapping is not possible between them. Therefore, a novel hybrid mapping mechanism has been proposed to integrate these two completely non-identical devices. This paper also describes the detailed dynamic modeling of the parallel manipulator and the UAV. Modeling of the parallel manipulator is derived by physics of the system while for the UAV, a method of system identification is used. The level of tracking accuracy presented in the simulation results verifies the efficacy of the system modeling, hybrid mapping, and overall controlmechanism. Multilevel control architecture based on PID controllers, in local actuator joint spaces, for the master manipulator and the slave UAV is also presented in this work.
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Huang Xiaoqian,Hamad Karki,Amit Shukla,Zhang Xiaoxiong 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10
This paper presents an improved autonomous navigation control mechanism for a UAV for accurate tracking and inspection of the ground laid linear horizontal structures such as oil and gas pipelines. At first, the Canny Edge Detector (CED) and the Probabilistic Hough Transformation (PHT) are used to identify the structures based on visual data collected by the onboard camera. Then suitable geometrical parameters are extracted from the collected structure information to design controller mechanism of the UAV for autonomous tracking along the identified linear structure. For autonomous tracking, the development of an appropriate controller is significant because it affects the overall response time, sensitivity, accuracy of the tracking performance by the UAV. Through analyzing the previous research results of pipeline recognition and the UAV navigation by velocity mapping [1], it can be seen that the overall lateral correction of the navigation path based on the conventional PID has obvious disadvantages such as a slow response time, UAV oscillation, angular and lateral instability etc. Especially for a low-altitude tracking, the tracking target is prone to be out of camera view very quickly. Thus a new controller with variant coefficients is designed for a better tracking performance. Combined with the previous research achievement, this paper emphasizes the principal and the allocation of the newly designed variant PID controller.
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Amit Shukla,Huang Xiaoqian,Hamad Karki 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10
This paper presents automated navigation control of an Unmanned Aerial Vehicle (UAV) based on visual data gathered by onboard camera. With depletion of easy resources and health, safety and environmental (HSE) challenges in exploiting newly found resources in hostile conditions are forcing oil and gas companies to look for robotic solutions for their problems. Pipelines carrying inflammable and toxic petroleum products are one of the most critical component of oil and gas industry. Being laid in extreme environmental conditions these critical assets require continuous inspection and maintenance. An UAV carrying non-contact sensors is proposed to use for external inspection of the visible pipeline sections. Till now UAVs are mostly used for general purpose visual surveillance while flying at very high altitude but in this novel work we propose accurate tracking and inspection while flying at very low altitude in close vicinity of the ground pipeline structure. Proposed automated inspection of the pipelines by the UAV has two stages firstly identification of the pipeline and secondly navigation control of the UAV for tracking of the pipeline structure. Both identification and tracking are based on visual data gathered by onboard cameras without any additional help of GPS information. This novel navigation control mechanism further has double layers of correction loops namely angular and lateral corrections. Navigation control uses heuristically tunes PID controllers and required geometrical parameters for angular and lateral corrections are extracted from visual data generated by onboard video camera.
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Vision based Autonomous Landing of an Unmanned Aerial Vehicle on a Stationary Target
Vidya Sudevan,Amit Shukla,Hamad Karki 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10
The foremost, yet challenging problem of an Unmanned Aerial Vehicle (UAV) is the autonomous landing. This paper presents a solution for the independent landing of a quadrotor UAV on a stationary target. This method includes a searching and a landing part. The visual data is collected by the onboard camera of the AR Drone. Speeded Up Robust Features (SURF) method is used to detect and compute the keypoint descriptors and Fast Approximate Nearest Neighbor Search Library (FLANN) based descriptor matcher is utilized for the accurate matching of the template image with the captured images to determine the target position. The aim of this method is to minimize the distance between the drone and the target. A Proportional-Integral-Derivative (PID) controller is designed to generate the desired velocity signals for the drone. Also, in this work, the drone is directly navigating and landing on the target by adjusting the x , y and z velocities simultaneously. The method is tested and validated on a quadrotor with two different initial heights.
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Current and Future Research Focus on Inspection of Vertical Structures in Oil and Gas Industry
Vidya Sudevan,Amit Shukla,Hamad Karki 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10
Regular inspection of oil and gas installations are vital for production, maintenance, safety and environmental impact assessment. Due to complex set-up and hazardous operation environment, the inspection, maintenance and repair (IMR) operations as considered as an inevitable task in oil and gas industries. Integrating technologies from the field of robotics, sensing and process control will be a decisive step in digitalization of oil and gas industry. The traditional vertical structures inspection system uses rope access, scaffolds, telescopic elevation platforms supported by cranes and manned helicopters. The challenges faced by conventional techniques are the construction of scaffolding, sending inspectors into dangerous and fatal environments, shutdown of plant operations etc. that has financial burden on the plant operating cost. Introduction of robotic technologies such as wall-climbing robots, Unmanned Aerial Vehicle (UAV) and wall-climbing drones, provides a possible solution for these challenges by increasing the efficiency, reducing the risks and lowering the cost of IMR tasks. The current research focus in this field is to automate and improve the inspection and testing capabilities of these systems. This paper presents the state of art of current scenario and future research focus on vertical structure inspection in oil and gas industry.
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