P. Chatzakos, Y.P. Markopoulos, K. Hrissagis and A. Khalid
The development of a novel omni‐directional inspection robot is presented, which is capable of delivering NDT sensors to surfaces on straight pipe, pipe bends and branch…
Abstract
Purpose
The development of a novel omni‐directional inspection robot is presented, which is capable of delivering NDT sensors to surfaces on straight pipe, pipe bends and branch connections, overcoming the limitation that a test area over a pipe bend or past a branch or other obstruction raise.
Design/methodology/approach
The lightweight crawler is attached on the outside of the pipe to the thin metal strip that holds the insulation in place without deforming the insulation through the application of a force controlled clamping mechanism while performing longitudinal, circumferential and arbitrary movements. In order to be able to cope with a range of pipe, materials and coverings, to allow for future modifications and to be able to incorporate a wide range of NDT inspection equipment, a modular approach was considered for the design of the mobile robot. Either two different inspection sensors may be mechanically incorporated into the chassis of the crawler and deployed at the same time or just a double‐sided acting sensor (e.g. X‐ray).
Findings
The developed omni‐directional mobile robot is capable of delivering NDT sensors to the external surfaces on straight pipe, pipe bends and branch connections, overcoming the limitation that a test area over a pipe bend or past a branch or other obstruction raise. Either a double‐sided acting sensor or two different inspection sensors may be mechanically incorporated and deployed at the same time. Future work will primarily include optimisation of the current design of the crawler aiming at further reduction of its size and weight but without sacrificing the rigidness of the chassis. A perfectly balanced system, which in turn will lead to smaller DC servo motors, will be obtained either by systematic placement of various subsystems and components on the periphery of the chassis or by putting counterbalancing weights in appropriate locations on the chassis. Design and manufacture of custom‐made omni‐wheels exclusively for use with the proposed clawer is also included in the scope of future work. Finally, a sophisticated control scheme for special, uncommon and fully automated inspection routines will be developed.
Originality/value
Today, there are no commercially available current inspection techniques that can accurately detect significant corrosion or other types of defects in pipework under thick coatings. Another limitation is that current inspection techniques can only be applied manually by highly trained operators. Recent PANI trials, carried out to assess the effectiveness of manual inspections have shown that operators detect only 50 per cent of defects. Commercial scanners have been developed for scanning pipe girth welds and lengths of straight pipe with inspection sensors. These are primarily ultrasonic sensors and the scanning is in simple X‐Y routines. These scanners either move around the pipe on tracks or along the pipe on magnetic wheels. However, these cannot work on curved surfaces around pipe bends and in the vicinity of valves, branches and other features in the pipe. Unluckily, these are areas where corrosion is most likely to occur.
Details
Keywords
The purpose of this paper is to propose a suitable motion planning for omni‐directional mobile robots (OMRs) by taking into account the motion characteristics.
Abstract
Purpose
The purpose of this paper is to propose a suitable motion planning for omni‐directional mobile robots (OMRs) by taking into account the motion characteristics.
Design/methodology/approach
Based on the kinematic and dynamic constraints, the maximum velocity, motion stability and energy consumption of the OMR moving in different directions are analysed, and the anisotropy of the OMR is presented. In order to obtain the optimal motion, the path that the robot can take in order to avoid the obstacle safely and reach the goal in a shorter path is deduced. According to the new concept of anisotropic function, the motion direction derived from traditional artificial potential field (tAPF) is regulated.
Findings
A combination of the anisotropic function and tAPF method produces high‐speed, highly stable and efficient motion when compared to the tAPF. Simulations and experiments have proven the validity and effectiveness of this method.
Research limitations/implications
The practical factors, such as the effect of wear on the omni‐directional wheels, are not considered. Typical problems of APF, e.g. local minima, are not addressed here. In our future research, we will deal with these issues.
Practical implications
The proposed motion planning is applicable for any kind of OMRs, both three‐ and four‐wheeled OMRs, which can fully exhibit the advantages of OMRs.
Originality/value
The new concept of an anisotropic function is proposed to indicate the quality of motion in different directions. Different motion effects can be obtained in the same direction with different weights denoted by the anisotropic function, i.e. different trade‐offs can be achieved by varying the weights.
Details
Keywords
Jianming Yuan, Xinjun Wu, Yihua Kang and Chen Huang
Damage of oil and gas long‐distance transmission pipelines caused by corrosion, stresses, geological change, and other factors can result in catastrophic failures. The purpose of…
Abstract
Purpose
Damage of oil and gas long‐distance transmission pipelines caused by corrosion, stresses, geological change, and other factors can result in catastrophic failures. The purpose of this paper is to describe a mobile out‐pipe inspection robot for the pipeline inspection.
Design/methodology/approach
This paper adapts to the requirements of long‐distance transmission pipelines on‐site overhaul, the robot developed in this paper utilizes a local magnetic flux leakage testing method for the pipeline inspection. Detection, walking, attachment, steering, and control units are designed for the robot.
Findings
The detection apparatus of the robot plays dual roles as detection and attachment unit. So, the structure of the robot is relatively simple and it is relatively small in size and relatively light.
Practical implications
A prototype of the robot has been manufactured according to the design. Results of the test in lab show the robot can be used to inspect pipe.
Originality/value
The robot is able to scan and inspect the pipeline along the planned route automatically.
Details
Keywords
Vivian Suzano Medeiros, Alan Conci Kubrusly, Raphael Lydia Bertoche, Miguel Andrade Freitas, Claudio Camerini, Jorge Luiz F. Brito and Jean Pierre von der Weid
The inspection of flexible risers is a critical activity to ensure continuous productivity and safety in oil and gas production. The purpose of this paper is to present the design…
Abstract
Purpose
The inspection of flexible risers is a critical activity to ensure continuous productivity and safety in oil and gas production. The purpose of this paper is to present the design and development of a novel automatic underwater tool for riser inspection that fits the most commonly used riser diameters and significantly improves inspection quality and reduces its operating costs.
Design/methodology/approach
The mechanical and electronic design of the inspection system is discussed, as well as its embedded sensors and control system. The tool is equipped with a suspension system that is able to adapt to the riser diameter and negotiate obstacles on the pipe wall. Numerical simulations were carried out to analyze the mechanical design, and a hardware-in-the-loop simulation was developed for tuning the control system. Further, experimental results are presented and discussed.
Findings
Experimental tests in laboratory tanks and shallow seawater have confirmed the effectiveness of the tool for detailed real-time inspection of underwater pipelines.
Practical implications
The use of the proposed tool will potentially reduce the time and costs for riser inspection, currently performed by divers or high-cost ROVs.
Originality/value
The authors present a reliable tool able to perform automatic inspections up to 250 m deep in less than 30 min, equipped with a high-definition visual inspection system, composed of full-HD cameras and lasers and a suspension mechanism that can negotiate sharp obstacles in the pipe wall up to 25 mm high. The tool uses a comprehensive control system that autonomously performs a full inspection, collecting sensors data and returning safely to the surface. Its robust design can be used as basis for several other nondestructive techniques, such as ultrasound and X-ray.
Details
Keywords
Chuntao Leng, Qixin Cao and Charles Lo
The purpose of this paper is to propose a suitable motion control method for omni‐directional mobile robots (OMRs) based on anisotropy.
Abstract
Purpose
The purpose of this paper is to propose a suitable motion control method for omni‐directional mobile robots (OMRs) based on anisotropy.
Design/methodology/approach
A dynamic modeling method for OMRs based on the theory of vehicle dynamics is proposed. By analyzing the driving torque acting on each axis while the robot moves in different directions, the dynamic anisotropy of OMRs is analyzed. The characteristics of dynamic anisotropies and kinematic anisotropies are introduced into the fuzzy sliding mode control (FSMC) system to coordinate the driving torque as a factor of influence.
Findings
A combination of the anisotropy and FSMC method produces coordinated motion for the multi‐axis system of OMRs, especially in the initial process of motion. The proposed control system is insensitive to parametric vibrations and external disturbances, and the chattering is apparently decreased. Simulations and experiments have proven that an effective motion tracking can be achieved by using the proposed motion control method.
Research limitations/implications
In order to obtain a clearer analysis of the anisotropy influence during the acceleration process, only the case of translation motion is discussed here. Future work could be done on cases where there are both translation and rotation motions.
Practical implications
The proposed motion control method is applied successfully to achieve effective motion control for OMRs, which is suitable for any kind of OMR.
Originality/value
The novel concept of dynamic anisotropy of OMRs is proposed. By introducing the anisotropy as an influential factor into the FSMC system, a new motion control method suitable for OMRs is proposed.
Details
Keywords
Melquisedec F. Santos, Maurício O. Brito, Cassiano Neves and Luciano L. Menegaldo
The purpose of this paper is to describe a new multi‐sensor robotic system designed for riser, mooring lines and umbilical cables in situ underwater inspection. Due to the…
Abstract
Purpose
The purpose of this paper is to describe a new multi‐sensor robotic system designed for riser, mooring lines and umbilical cables in situ underwater inspection. Due to the aggressive operation environment, such structures are susceptible to a broad spectrum of failure causes, such as aging, mechanical, chemical and thermal loads, hydrodynamic stresses, vortex‐induced vibrations and installation or fabrication non‐conformities. Current inspection methods present major risks and inefficiencies, especially as deeper fields are being reached for exploitation.
Design/methodology/approach
The SIRIS (In Situ Riser Inspection Robotic System) is designed to reconstruct the actual riser profile and perform non‐destructive tests. The robot is propelled by thrusters to scroll by the outside of the catenary riser. Mechanical, electronic hardware, image acquisition and software/firmware design are described here.
Findings
Simulated data from an inertial measurement unit is fused with depth sensor measurements, using a Kalman filter to reconstruct the riser profile, with small localization errors. Laboratory and sheltered waters tests were successfully executed to assess robot subsystems' performance: imaging, leakage, displacement and easiness of operation.
Research limitations/implications
The robot prototype is designed to operate down to 250 m deep, although the final goal is reaching 3,000 m. Tests offshore, in a real oil production platform, have not been performed up to this moment. In the present version, the robot must be coupled to the riser with the aid of a scuba diver.
Practical implications
The robot is expected to allow non‐destructive testing in risers that cannot be performed nowadays with the existing tools. The inspecting procedure is easy to operate and does imply any kind of production stopping. More accurate assessment of the riser structural condition can allow extending its life span, thus avoiding early decommissioning.
Social implications
Better assessment of actual riser facilities status will have great impact on reducing the chance of oil spill episodes and serious environment damage.
Originality/value
The design, construction and evaluation of a robotic tool for non‐destructive riser inspection has been described. A few similar robots exist in literature but none of them is able to reconstruct the actual riser profile.
Details
Keywords
Zhong Wei, Guangming Song, Huiyu Sun, Qien Qi, Yuan Gao and Guifang Qiao
This paper aims to study the turning strategies for the bounding quadruped robot with an active spine and explore the significant role of the spine in the turning locomotion.
Abstract
Purpose
This paper aims to study the turning strategies for the bounding quadruped robot with an active spine and explore the significant role of the spine in the turning locomotion.
Design/methodology/approach
Firstly, the bounding gait combining the pitch motion of the spine with the leg motion is presented. In this gait, the spine moves in phase with the front legs. All the joints of the legs and spine are controlled by cosine signals to simplify the control, and the initial position and oscillation amplitude of the joints can be tuned. To verify the effectiveness of the proposed gait, the spine joints are set with different initial positions and oscillation amplitudes, and the initial position and oscillation amplitude of the leg joints are tuned to make the virtual model do the best locomotion in terms of the speed and stability in the simulation. The control signals are also used to control a real robot called Transleg. Then, three different turning strategies are proposed, including driving the left and right legs with different strides, swaying the spine in the yaw direction and combining the above two methods. Finally, these strategies are tested on the real robot.
Findings
The stable bounding locomotion can be achieved using the proposed gait. With the spine motion, the speed of the bounding locomotion is increased; the turning radius is reduced; and the angular velocity is increased.
Originality/value
A simple and flexible planning of the bounding gait and three turning strategies for the bounding quadruped robot are proposed. The effectiveness of the proposed bounding gait, along with the beneficial effect of the spine motion in the yaw direction on the turning locomotion is demonstrated with the computer simulations and robot experiments. This will be instructive for the designing and actuating of the other quadruped robots.
Details
Keywords
Jinchang Fan, Canjun Yang, Yanhu Chen, Hansong Wang, Zhengming Huang, Zhicheng Shou, Ping Jiang and Qianxiao Wei
This paper aims to present an underwater climbing robot for wiping off marine life from steel pipes (e.g. jackets of oil platforms). The self-adaption mechanism that consists of a…
Abstract
Purpose
This paper aims to present an underwater climbing robot for wiping off marine life from steel pipes (e.g. jackets of oil platforms). The self-adaption mechanism that consists of a passive roll joint and combined magnet adhesion units provides the robot with better mobility and stability.
Design/methodology/approach
Adhesion requirements are achieved by analyses of falling and slipping. The movement status on pipes is analyzed to design the passive roll joint. The optimized structure parameters of the combined magnet adhesion unit are achieved by simulations. An approximation method is established to simplify the simulations conditions, and the simulations are conducted in two steps to save time effectively.
Findings
The self-adaption mechanism has expected performance that the robot can travel on pipes in different directions with high mobility. Meanwhile, the robot can clean continuous region of underwater pipes’ surface of offshore platforms.
Practical implications
The proposed underwater robot is needed by offshore oil platforms as their jackets require to be cleaned periodically. Compared with traditional maintenance by divers, it is more efficient, economic and safety.
Originality/value
Due to the specific self-adaption mechanism, the robot has good mobility and stability in any directions on pipes with different diameters. The good performance of striping attachments from pipes makes the underwater robot be a novel solution to clean steel pipes.