Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> In-pipe robots are mostly applied to exploration and maintenance of pipelines in the industry where is hard to perform by manual operation. As their study involves many disciplines and it is one of the important development directions in the field of robot research, and has important research value and wide application foreground. This paper presents the significance and prospects, and comprehensively analyzes the typical pipeline robot developed at home and abroad. On the basis of characteristic and performance analysis of different kinds of pipeline robot locomotion pattern, the paper points out the key issues such as energy supply. that the research of pipeline robot is encountering. <s> BIB001 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> This paper deals with a design and motion planning algorithm of a caterpillar-based pipeline robot that can be used for inspection of 80-100-mm pipelines in an indoor pipeline environment. The robot system uses a differential drive to steer the robot and spring loaded four-bar mechanisms to assure that the robot expands to grip the pipe walls. Unique features of this robot are the caterpillar wheels, the analysis of the four-bar mechanism supporting the treads, a closed-form kinematic approach, and an intuitive user interface. In addition, a new motion planning approach is proposed, which uses springs to interconnect two robot modules and allows the modules to cooperatively navigate through difficult segments of the pipes. Furthermore, an analysis method of selecting optimal compliance to assure functionality and cooperation is suggested. Simulation and experimental results are used throughout the paper to highlight algorithms and approaches. <s> BIB002 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> The article deals with development and application of snake robot for inspection pipes. The first step involves the introduction of a design of mechanical and electrical parts of the snake robot. Next, the analysis of the robot locomotion is introduced. For the curved pipe, potential field method is used. By this method, the system is able to generate path for the head and rear robot, linking the environment with obstacles, which are represented by the walls of the pipe. Subsequently, the solution of potential field method is used in inverse kinematic model, which respects tasks as obstacle avoidance, joint limit avoidance, and singularity avoidance. Mentioned approach is then tested on snake robot in provisional pipe with rectangular cross section. For this research, software Matlab (2013b) is used as the control system in cooperation with the control system of robot, which is based on microcontrollers. By experiments, it is shown that designed robot is able to pass through straight and also curved pipe. <s> BIB003 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> Abstract Hydraulic Transient is one of the most destructive effects in oil and gas pipelines. Currently existing pigs are one of the main sources for this phenomena due to their physical characteristics and function. In this study, by implementation of a new design to the system of pigs, which utilizes the free spaces surrounding the robot, the effect of hydraulic transient is fully eliminated. To demonstrate the practicality and significance of this study, several various simulation experiments such as laminar flow, pressure distribution, velocity variations and stress analysis are conducted on the new design with adjustable arms as well as the former design utilizing sealing disks. The benefit of using adjustable arms exceeds the goal of this research and makes the design extremely versatile by giving it the ability of multi-diameter pipeline inspection and speed maintenance to derive highest resolution for inspection sensors. <s> BIB004 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> In-pipe inspection robots are designed to remove the manpower and to work in inaccessible situation. This paper describes an in-pipe inspection robot (IPIR) which consist of a fore leg system, rear leg system and a body. The fore and rear leg systems are symmetric and are constructed by using three legs. Three legs of each leg system are arranged at an angle of 120 degree with respect to each other to operate inside a pipe. The springs are put into lower section of legs to operate inside pipes of 230mm to 300mm diameter range. In this paper, mechanical design of all major components of robot is done. Solid modeling of all robot components and its assembly is done in Solidworks 14. Several experiments are conducted in pipes of different diameters and effectiveness of steering mechanism is confirmed. This robot can be used for offline visual inspection of varies pipe elements such as straight pipe, elbows and reducers. Also it can be used to find the defects and place of defects in the pipe. This robot also has wide applications in gas pipelines, water pipelines and drain pipes etc. Also it has wide scope in chemical industries as well as in gulf countries for inspection of oil and gas pipelines. <s> BIB005 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> AbstractThis paper presents a multilink-articulated robot with omni and hemispherical wheels (AIRo-2.1) for inspecting and exploring pipelines. To quickly adapt to winding pipes, holonomic rolling movement without moving forward and backward is useful. However, this requires the rolling actuators to replace the driving actuators at the expense of the driving force. Furthermore, so far the number of driving wheels and torsion springs, magnitude of driving forces, stiffness and natural angle of the spring that are required to adapt to various pipelines have not been clarified. In this paper, we investigate the possibility of high maneuverability of multilink-articulated robots in winding pipes with as few driving actuators as possible and only elastic joints (torsion springs) for body bending. We further validate its effectiveness by experimental verification. <s> BIB006 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> The paper presents the external pipe locomotion of a robot for inspection and monitoring of the pipelines for use in oil and gas industry. During regular motion, the robot resembles to a crank-slider mechanism with equal lengths of the crank and rod, while for stepping over flanges it becomes an open chain with double actuated leverage. A bond graph model and simulation results by use of 20-sim environment are also presented. <s> BIB007 </s> Inspection Robots in Oil and Gas Industry: a Review of Current Solutions and Future Trends <s> 2) Onshore Pipeline Inspection <s> A Steerable in-pipe inspection robot is designed in this paper and its optimal control based on linear quadratic regulator (LQR) approach is performed subject to input minimization. In-pipe inspection robots are necessary mobile robots in order to investigate the pipelines. Most of the in-pipe inspection robots are limited to move with a constant pitch rate. An in pipe inspection robot is proposed in this paper which is based on screw locomotion and its steering angle is also controllable in order to handle the pitch rate of the movement and bypass the probable obstacles. Since the proposed robot is multivariable with more than one controlling input, minimizing its control inputs are extremely useful. The goal of this paper is to extract the dynamic model of the mentioned steerable screw in-pipe inspection robot and controlling it within a predefined trajectory in an optimal way. The proper mechanism is designed and its related kinematics and kinetics are derived. Afterwards the objective function is defined based on minimizing the controlling input and maximizing the accuracy of movement. The nonlinear state space is linearized around its operating point and optimization is implemented using Linear Quadratic Regulator (LQR). The efficiency of the designed robot and controller and the optimality of its controlling procedure are investigated by the aid of MATLAB simulation and comparative analysis. It is proved that the designed robot is able to move with controllable pitch rate and acceptable accuracy while the obstacles can be avoided and the energy consumption is optimized. At the end the validity of modeling and simulation in MATLAB is also verified by modeling the robot in ADAMS and comparing the results. <s> BIB008
For onshore pipeline inspection robots, the style of locomotion is a vital part, which can reflect the whole performance of the robots BIB001 . According to the difference of driving source and control ability of movement mechanism, robots can be sorted into pig, wheeled, tracks, legged, inchworm, snake and screw type  . Fig.3 gives some examples about these kinds of robots. Figure 3 . (a) The pig type BIB004 , (b)The wheel type BIB006 , (c) The track type BIB002 , (d) The legged type BIB005 , (e) The inchworm type BIB007 , (f) The snake type BIB003 , (g) The screw type BIB008 . The pig type BIB004 itself is a simply device which collects the data of the pipeline. The pig carries out the inspection tasks along the flow of oil or gas. What is more, the pig has no driving mechanism and is driven through the pipeline by oil or gas flow. The wheel type BIB006 uses wheels to touch the pipe wall. It can easily adapt to various pipelines with springs. The track type BIB002 is often treated as the alternative to the wheeled robot. Wheels are bounded with the belt, which can enlarge the surface contact area and reduce chances of losing pipe wall contact. The legged type BIB005 uses legs to contact with the pipe wall. This type of robots can produce highly sophisticated motions and is suitable for pipes with obstacles. The inchworm type BIB007 uses the traction generated by the large force applied to the front or back module. Compared with other types of inspection robots, it has an advantage in curved pips. Snake type BIB003 consists of several identical body segments with joints, which allows it to generate a wide range of different motions. The screw type BIB008 moves forward through the rotary motion, achieving a good performance in vertical pipelines.