Development of a novel autonomous robot for navigation and inspect in oil wells

This paper proposes a novel robotic system that is able to move along the outside of the oil pipelines used in Electric Submersible Pumps (ESP) and Progressive Cavity Pumps (PCP) applications. This novel design, called RETOV, proposes a light weight structure robot that can be equipped with sensors to measure environmental variables avoiding damage in pumps and wells. In this paper, the main considerations and methodology of design and implementation are discussed. Finally, the first experimental results that show RETOV moving in vertical pipelines are analyzed

Design and Development of a Mobile Climbing Robot for Wind Turbine Inspection

Wind turbines (WT) have become an essential renewable energy source as the contribution of WT farms has reached megawatts scale. However, wind turbine blades (WTB) are subjected to failure due to many loading effects such as aerodynamic, gravity and centrifugal loads and operation in harsh environments such as ultraviolet (UV) radiation, ice, hail, temperature variation, dirt, and salt. As a result, the blades suffer different types of damage. Consequently, a periodic inspection process is required to detect and repair defects before a catastrophic failure happens. This thesis presents a literature review of wall climbing robots to identify the most appropriate locomotion and adhesion method to use for a WT climbing machine that can take a large payload of non-destructive testing (NDT) sensors up to a blade and deploy them with scanning arms. A review of wind turbine blade construction, various loading effects on blades and types of damage in blades is followed by a review of the NDT techniques used for inspecting WTB. The above review determines the design requirements to achieve the aim of the current research which is to design a low-cost and reliable mobile robot which will be able to climb the WT tower and subsequently scan the blade surface to perform the inspection using various sensors to identify and classify damages. This robot system should be able to access all the critical areas of the blade structure in a stable and secure way. It should be stable enough to allow the various test sensors to scan the blade structure in the shortest possible time. The thesis describes the development of a tower climbing robot that uses magnetic adhesion to adhere to the WT. As a preliminary study, a simulation model is developed using COMSOL Multiphysics to simulate the magnetic adhesion force while climbing the tower. A test rig is designed and fabricated to measure the magnetic adhesion force experimentally to validate the simulation model. The response surface methodology (RSM) using Box-Behnken design (BBD) is used to design and perform experiments to optimise different independent variables i.e. air gap, the distance between magnets in an array and backplate (yoke) thickness that affect the magnetic adhesion force. A scaled-down prototype magnetic adhesion climbing robot has been designed and constructed for wind turbine blade inspection. The robot is 0.29 m long with two 1.0 m long arms, weighs 10.0 kg and can carry a maximum 2.0 kg payload of NDT sensors. Optimum design of a magnetic adhesion mechanism has been developed for the climbing robot prototype that maximises the magnetic adhesion force. The robot is equipped with two arms that can be extended by one meter to come close to the blade for inspection. Each arm is equipped with a gripper that can hold an inspection tool of weight up to one kilogram. A scaled-down wind turbine has been modelled using SolidWorks and a portion of it constructed to experimentally test the scaled-down climbing robot. To scale up the robot prototype for operation on a normal sized wind turbine, a 100 m tall wind turbine with three 76 m long blades has been modelled and the prototype robot scaled up based on these dimensions. The scaled-up robot is 3.0 m long, weighs 1135 kg and has two 10 m long arms. Static stress analysis and flow simulation have been carried out to check the durability of the scaled-up robot while climbing the wind turbine tower. The procedure for scaling up the adhesion mechanism to achieve equilibrium of the robot has been introduced based on the reaction force concluded from the static stress and flow simulation study. As a result, the maximum payload that each arm can carry has been calculated for both the scaled-down prototype (1 kg) and the scaled-up design (50 kg). This concludes the utility and robustness of the wall climbing robot as a robotic solution for wind turbine blade inspection

CUHK electronic theses & dissertations collection

近年來，空間機器人被廣泛應用於低地球軌道的空間服務中，其中包括太空船艙內、艙外的活動。因應艙外的活動，空間機器人經常以地面工業用機械臂的形式設計，並擁有相似的關節配置。空間機械臂的關節配置，主要可以分成兩類。第一類是六自由度空間機械臂，例如，太空梭遙控機械手系統SRMS，工程試驗衛星七號RTS-VII '和日本實驗模組遙控器系統JEMRMS 。另一類是七自由度空間機械臂，例如，歐洲機械臂ERA和空間站遠距離機械手系統SSRMS。他們不但能在空間站上完成不同的操作任務，而且能於空間站上進行攀爬。在一個自由飄浮的環境中，空間機械臂的運動會影響太空站的姿態。因此，空間站的姿態穩定對維持太陽能板的接收和系統通訊的信號強度發揮非常重要的作用。大部份太空站姿態穩定的研究都集中於對機械臂的操作運動進行控制。然而，針對機械臂的移動進行優化的研究卻不多。由於空間機械臂的工作空間有限，在空間站上的移動能力是必要的，因此該運動對空間站的影響是無法避免。有見及此，本論文提出一種新型空間站移動技術，從而減低因機械臂移動時對空間站造成的干擾。在維持現有空間機械臂的關節配置下，提出種結合驅動輸和傳統機械手抓優點的新型手抓概念。為了實現這種新型手抓概念，本論文提出了種新型的支架攀爬機械人，名為Frambot' 並在Frambot上實現了新式手抓的設計與應用。Frambot 的設計主要針對不能進行包圍性抓緊的方型析架進行攀爬，手抓的握持力是通過壓縮彈簧而產生，實現低能耗攀爬，提高Ftambot在析架上的工作時間。為了提高Ftambot在析架攀爬時的穩定性，本論文在Ftambot設計了個簡單、不需要傳感器反饋的傾斜修正結構。另外，在Frambot 的平臺上實驗了新式的攀爬運動，從而證明利用驅動輪的原理在析架上進行攀爬的可行性。基於這種新型的手抓，本文為空間機械臂設計出新式空間站移動步履，並分析新式空間站移動步履對空間站造成的干擾。由於傳統的空間機器人系統建模是針對於機械臂的操作運動，因此本文針對機械臂利用驅動輪移動時，對空間站的姿態變化進行建模，並建立一個實驗平臺去對該模型進行驗證。此外，利用空間機械臂的系統模型，對新式的移動步履進行動態運動仿真。透過和傳統的移動步履進行比較，總結出新式的移動步履在空間站的姿態影響和能量需要都是最低的。在一個自由飄浮的環境中，空間機械臂的步履時間越長，對太空站的干擾就越大。另外，空間站的能源是有限的，所以減低空間機臂對空間站的能耗十分重要。本論文考慮到實際的應用，空間機械臂需要移動到空間站上不同的地點完成操作任務，因此提出了空間機械臂在桁架移動時的路徑規規劃方案，目的在於對路徑的總長度和能量需求進行優化。本文提出的路徑規劃演算法，透過利用遺傳演算法，對開型和閉合路徑進行優化。此外，在演算法中引多個新的概念，從而改善遺傳演算法的收斂速度和結果。最後，通過不同類型的仿真，對路徑規劃演算法的性能進行評估。The application of space robots has become more popular in performing tasks such as Intra and Extra Vehicular Activities (EVA) in Low Earth Orbit. For EVA, space robots were always designed as a chain-like manipulator with a joint configuration similar to on the earth robotic arm. Based on their joint configuration, they can be classified into two main categories. The first one is the six degrees of freedom (DOF) robotic arm including Shuttle Remote Manipulator System (SRMS), Engineering Test Satellite No. 7 (ETSVII), the Main Arm (MA) and the Small Fine Arm (SFA) of Module Remote Manipulator System (JEMRMS). The other group is the seven-DOF space robotic arm which includes European Robotic Arm (ERA) and Space Station Remote Manipulator System (SSRMS), or Canadarm2. They not only perform manipulation tasks, but also be able to navigate on the exterior of the International Space Station (ISS).In a free floating environment, motions of a space robotic arm cause the attitude change of a space station because of their dynamic coupling effect. Hence, the stabilization of the space station attitude is important to maintain the electrical energy generated by the solar panels and the signal strength for communication. Most of research in this area focuses on the motion control of a space manipulator through the study of Generalized Jacobian Matrix. Little research has been conducted specifically on the design of locomotion mechanism of a space manipulator.This dissertation proposes a novel methodology for the locomotion on a space station which aims to lower the disturbance on a space station. Without modifying the joint configuration of conventional space manipulators, the use of a new gripping mechanism is proposed which combines the advantages of active wheels and conventional grippers. To realize the proposed gripping mechanism, this dissertation also presents the design of a novel frame climbing robot (Frambot) which is equipped with the new gripping mechanism, named movable gripper (MovGrip). It is capable of climbing non-enclosable rectangular trusses and the gripping force is generated by the compression of springs. Therefore, the energy consumption in static gripping is zero which allows itself to stay on a truss for a long time. To enhance the climbing stability, a simple and sensor-free auto-tilting correction mechanism is designed. Based on the robot prototype, novel climbing gaits are designed and realized and this verifies the feasibility of using wheels motion in climbing trusses.With the use of the proposed gripping mechanism, new gaits are designed for space manipulators and the corresponding disturbance on a space station is analyzed. Since conventional modeling of a space station system focuses on manipulation tasks, this dissertation extends the model to formulate the dynamic coupling effect during wheels navigation. To verify the formulations, an experimental platform is designed and developed. Based on the system model, the proposed gaits are simulated and the results are compared with conventional gaits. From the simulation results, it can be concluded that the proposed gaits are better than conventional gaits in terms of minimum dynamic disturbance and energy demand on a space station.In a free floating environment, the longer a gait is performed, the greater the disturbance is generated on a space station. Also, the energy source of a space station is limited and the minimization of the energy consumption of a robot is important. Therefore, this dissertation also proposes a path planning algorithm which aims to minimize the total traveling distance and energy demand when a space manipulator is commanded to reach a target position for certain missions. For the proposed algorithm, both closed and open paths are considered and the optimizations are based on the conventional genetic algorithm. To enhance the convergent rate and final solutions, several novel concepts are introduced. Different simulation are performed and the results are presented to evaluate the performance of the proposed path planning algorithm.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Chung, Wing Kwong.Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.Includes bibliographical references (leaves 164-172).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstract also in Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Background --- p.1Chapter 1.2 --- Related Work --- p.2Chapter 1.3 --- Motivation of the Dissertation --- p.9Chapter 1.4 --- Organization of the Dissertation --- p.10Chapter 2 --- Design Principles of Movable Gripper --- p.12Chapter 2.1 --- Preliminary Gripper Design --- p.12Chapter 2.2 --- Static Model: Gripping Force --- p.14Chapter 2.3 --- Dynamic Model: Tractive Force --- p.19Chapter 2.4 --- Anti-slip Strategy --- p.23Chapter 2.4.1 --- Vertical Truss Climbing --- p.24Chapter 2.4.2 --- Horizontal Truss Climbing --- p.27Chapter 2.4.3 --- Right-side-up Truss Climbing --- p.29Chapter 2.4.4 --- Arbitrary gripping orientation analysis --- p.31Chapter 3 --- Design of a Novel Frame Climbing Robot --- p.36Chapter 3.1 --- Introduction --- p.36Chapter 3.2 --- Mechanical Design --- p.40Chapter 3.2.1 --- Gripper Jaw --- p.42Chapter 3.2.2 --- Parallel Gripping Mechanism --- p.43Chapter 3.2.3 --- Rotation Axis of Wheels --- p.44Chapter 3.2.4 --- Body Linkage --- p.45Chapter 3.3 --- Design of Climbing Gaits --- p.48Chapter 3.3.1 --- Motion simulation --- p.48Chapter 3.4 --- Experiments and Results --- p.52Chapter 3.4.1 --- Grasp’s Contact --- p.52Chapter 3.4.2 --- Tilting Correction Capability --- p.53Chapter 3.4.3 --- Load Carrying Capability --- p.53Chapter 3.4.4 --- Performance of Frambot --- p.57Chapter 3.5 --- Summary --- p.60Chapter 4 --- Modeling Analysis: Robot and Space Station --- p.61Chapter 4.1 --- Introduction --- p.61Chapter 4.2 --- Modeling of a space station system --- p.62Chapter 4.3 --- Kinematics --- p.66Chapter 4.4 --- Linear and Angular Momentums --- p.68Chapter 4.5 --- Dynamics --- p.69Chapter 4.6 --- Modeling Analysis --- p.71Chapter 4.7 --- Summary --- p.84Chapter 5 --- Modeling Analysis: Disturbance in Space Station --- p.85Chapter 5.1 --- Introduction --- p.85Chapter 5.2 --- Categories of Locomotion --- p.86Chapter 5.2.1 --- Joint Configurations --- p.86Chapter 5.2.2 --- Linear Locomotion --- p.87Chapter 5.2.3 --- Turning --- p.88Chapter 5.2.4 --- Exterior Transition --- p.93Chapter 5.3 --- Analysis of Dynamic Disturbance --- p.96Chapter 5.3.1 --- Linear Locomotion --- p.97Chapter 5.3.2 --- Turning --- p.103Chapter 5.3.3 --- Exterior Transition --- p.107Chapter 5.4 --- Analysis of Energy Demand --- p.113Chapter 5.5 --- Summary --- p.117Chapter 6 --- Global Path Planning --- p.122Chapter 6.1 --- Shortest Distance Path Planning --- p.124Chapter 6.1.1 --- Problem Description --- p.127Chapter 6.1.2 --- The Framework of Genetic Algorithm --- p.128Chapter 6.1.3 --- Simulation Study and Discussion --- p.135Chapter 6.2 --- Minimum Energy Demand Path Planning --- p.144Chapter 6.2.1 --- Problem Description --- p.147Chapter 6.2.2 --- The Framework of Genetic Algorithm --- p.148Chapter 6.2.3 --- Simulation Study and Discussion --- p.154Chapter 6.3 --- Summary --- p.159Chapter 7 --- Conclusions --- p.160Chapter 7.1 --- Contributions --- p.160Chapter 7.1.1 --- Design a New Gripping Mechanism for Truss Climbing Robot --- p.160Chapter 7.1.2 --- Design and Develop a Novel Truss Climbing Robot --- p.161Chapter 7.1.3 --- Formulate and Analyze the Disturbance on a Space Station Under different Gaits --- p.161Chapter 7.1.4 --- Develop a Global Path Planning Algorithm for the Minimization of Total Traveling Distance and Energy Demand --- p.162Chapter 7.2 --- Recommendation for Future Research --- p.162Chapter 7.2.1 --- Design Optimization --- p.162Chapter 7.2.2 --- Autonomous Truss Climbing --- p.163Chapter 7.2.3 --- Multicriteria Path Planning Algotirhm --- p.16