Development of a self-propelled capsule robot for pipeline inspection.

This paper introduces a current research project carried out in the Robert Gordon University for developing the prototype of the vibro-impact capsule robot for pipeline inspection. The project aims to address the technical bottlenecks which have been encountered by current pipeline technologies with a particular focus on oil industry. In order to verify the concept, a dummy capsule prototype with a diameter of 80 mm is designed and manufactured for testing in a 2.5 meter long section of 140 mm nominal diameter clear PVCu pipe with a flow velocity up to 0.3 m/s. By using the experimental test bed, the prototype of the capsule system can be tested at various flow rates, and the experimental results could be used for comparing with CFD simulation results for optimization

Optimization and experimental verification of the vibro-impact capsule system in fluid pipeline.

This paper studies the prototype development of the vibro-impact capsule system aiming for autonomous mobile sensing for pipeline inspection. Self-propelled progression of the system is obtained by employing a vibro-impact oscillator encapsuled in the capsule without the requirement of any external mechanisms, such as wheels, arms, or legs. A dummy capsule prototype is designed, and the best geometric parameters, capsule and cap arc lengths, for minimizing fluid resistance forces are obtained through two-dimensional and three-dimensional computational fluid dynamics analyses, which are confirmed by wind tunnel tests. In order to verify the concept of self-propulsion, both original and optimized capsule prototypes are tested in a fluid pipe. Experimental results are compared with computational fluid dynamics simulations to confirm the efficacy of the vibro-impact self-propelled driving

Multi-Objective Design Optimization of the Leg Mechanism for a Piping Inspection Robot

This paper addresses the dimensional synthesis of an adaptive mechanism of contact points ie a leg mechanism of a piping inspection robot operating in an irradiated area as a nuclear power plant. This studied mechanism is the leading part of the robot sub-system responsible of the locomotion. Firstly, three architectures are chosen from the literature and their properties are described. Then, a method using a multi-objective optimization is proposed to determine the best architecture and the optimal geometric parameters of a leg taking into account environmental and design constraints. In this context, the objective functions are the minimization of the mechanism size and the maximization of the transmission force factor. Representations of the Pareto front versus the objective functions and the design parameters are given. Finally, the CAD model of several solutions located on the Pareto front are presented and discussed.Comment: Proceedings of the ASME 2014 International Design Engineering Technical Conferences \& Computers and Information in Engineering Conference, Buffalo : United States (2014

Proof-of-concept prototype development of the self-propelled capsule system for pipeline inspection.

This paper studies the prototype development for the self-propelled capsule system which is driven by autogenous vibrations and impacts under external resistance forces. This project aims for proof-of-concept of its locomotion in pipeline environment in order to mitigate the technical complexities and difficulties brought by current pressure-driven pipeline inspection technologies. Non-smooth multibody dynamics is applied to describe the motion of the capsule system, and two non-smooth nonlinearities, friction and impact, are considered in modelling. The prototype of the self-propelled capsule system driven by a push-type solenoid with a periodically excited rod has been designed to verify the modelling approach. The prototype contains a microcontroller, a power supply, and a wireless control module, which has been tested in a clear uPVC pipe via remote control. Various control parameters, e.g. impact stiffness, frequency and amplitude of excitation, are studied experimentally, and finally, the fastest progression of the system is obtained

A Comparative Study of the Vibro-Impact Capsule Systems with One-Sided and Two-Sided Constraints

This is the final version of the article. Available from Springer Verlag via the DOI in this record.This paper studies the dynamics of the vibro-impact capsule systems with one-sided and two-sided soft constraints under variations of various system and control parameters, including mass ratio, stiffness ratio, gap of contact, and amplitude and frequency of external excitation. The aim of this study is to optimise the progression speed and energy consumption of the capsule, and minimize the required cabin length for prototype design used for engineering pipeline inspection. Our studies focus on three systems: the capsule with a right constraint, the capsule with a right and a weak left constraints, and the capsule with a right and a strong left constraints. Bifurcation analyses show that the behaviour of the capsule with one-sided constraint is mainly periodic, and the dynamic responses of the other two capsules with two-sided constraints become complex when the stiffness of the left constraint increases. Based on our extensive comparisons, the following optimisation strategies are recommended. When the capsule speed is paramount, one can employ the two-sided capsule with a weak left constraint under large amplitude of excitation. When energy consumption is taken into account, the one-sided capsule is preferable. When a miniaturized prototype is needed, the two-sided capsule with a strong left constraint is the best choice.Dr. Yang Liu would like to acknowledge the financial support from EPSRC for his First Grant (Grant No. EP/P023983/1). Dr. Yao Yan was supported by the National Natural Science Foundation of China (Grant No. 11572224 and 11502048) and the Fundamental Research Funds for the Central Universities (Grant No. ZYGX2015KYQD033)

The vibro-impact capsule system in millimetre scale: numerical optimisation and experimental verification

This is the final version. Available on open access from Springer via the DOI in this recordData accessibility: The numerical and experimental data sets generated and analysed during the current study are available from the corresponding author on reasonable request.The vibro-impact capsule system has been studied extensively in the past decade because of its research challenges as a piecewise-smooth dynamical system and broad applications in engineering and healthcare technologies. This paper reports our team’s first attempt to scale down the prototype of the vibro-impact capsule to millimetre size, which is 26 mm in length and 11 mm in diameter, aiming for small-bowel endoscopy. Firstly, an existing mathematical model of the prototype and its mathematical formulation as a piecewise-smooth dynamical system are reviewed in order to carry out numerical optimisation for the prototype by means of path-following techniques. Our numerical analysis shows that the prototype can achieve a high progression speed up to 14.4 mm/s while avoiding the collision between the inner mass and the capsule which could lead to less propulsive force on the capsule so causing less discomfort on the patient. Secondly, the experimental rig and procedure for testing the prototype are introduced, and some preliminary experimental results are presented. Finally, experimental results are compared with the numerical results to validate the optimisation as well as the feasibility of the vibro-impact technique for the potential of a controllable endoscopic procedure.Engineering and Physical Sciences Research Council (EPSRC

A Novel Propeller Design for Micro-Swimming robot

The applications of a micro-swimming robot such as minimally invasive surgery, liquid pipeline robot etc. are widespread in recent years. The potential application fields are so inspiring, and it is becoming more and more achievable with the development of microbiology and Micro-Electro-Mechanical Systems (MEMS). The aim of this study is to improve the performance of micro-swimming robot through redesign the structure. To achieve the aim, this study reviewed all of the modelling methods of low Reynolds number flow including Resistive-force Theory (RFT), Slender Body Theory (SBT), and Immersed Boundary Method (IBM) etc. The swimming model with these methods has been analysed. Various aspects e.g. hydrodynamic interaction, design, development, optimisation and numerical methods from the previous researches have been studied. Based on the previous design of helix propeller for micro-swimmer, this study has proposed a novel propeller design for a micro-swimming robot which can improve the velocity with simplified propulsion structure. This design has adapted the coaxial symmetric double helix to improve the performance of propulsion and to increase stability. The central lines of two helical tails overlap completely to form a double helix structure, and its tail radial force is balanced with the same direction and can produce a stable axial motion. The verification of this design is conducted using two case studies. The first one is a pipe inspection robot which is in mm scale and swims in high viscosity flow that satisfies the low Reynolds number flow condition. Both simulation and experiment analysis are conducted for this case study. A cross-development method is adopted for the simulation analysis and prototype development. The experiment conditions are set up based on the simulation conditions. The conclusion from the analysis of simulation results gives suggestions to improve design and fabrication for the prototype. Some five revisions of simulation and four revisions of the prototype have been completed. The second case study is the human blood vessel robot. For the limitations of fabrication technology, only simulation is conducted, and the result is compared with previous researches. The results show that the proposed propeller design can improve velocity performance significantly. The main outcomes of this study are the design of a micro-swimming robot with higher velocity performance and the validation from both simulation and experiment

Self-propelled capsule endoscopy for small-bowel examination: proof-of-concept and model verification

This is the author accepted manuscript. The final version is available on open access from Elsevier via the DOI in this recordThis paper reports an experimental study of a vibro-impact self-propulsion technique applying for small-bowel endoscopy by using a mesoscale capsule prototype, which is 56.9 mm in length and 19.4 mm indiameter. Based on nonsmooth multibody dynamics, a mathematical model is developed for studying the dynamical characteristics of the prototype. Numerical and experimental results are compared to validate the efficacy of the proposed model as well as the feasibility of the technique under various frictional environment. By using the model, we can reveal some hidden dynamics of the prototype and optimise its progression speed and energy efficiency. Based on our calculations, by adopting this technique, the standard-sized capsule, which is 26 mm in length and 11 mm in diameter, can achieve the maximum average speeds of 8.49 mm/s for forward progression and 4.9 mm/s for backward progression, offering the potential for a ‘live’ and controllable small-bowel examinationEngineering and Physical Sciences Research Council (EPSRC

Modelling of a Vibro-Impact Self-Propelled Capsule in the Small Intestine

This is the author accepted manuscript. The final version is available from Springer via the DOI in this record.This paper studies the modelling of a vibro-impact self-propelled capsule system in the small intestinal tract. Our studies focus on understanding the dynamic characteristics of the capsule and its performance in terms of the average speed and energy efficiency under various system and control parameters, such as capsule’s radius and length, and the frequency and magnitude of sinusoidal excitation. We find that the resistance from the small intestine will be larger once capsule’s size or instantaneous velocity increases. From our extensive numerical calculations, optimum system and control parameters are obtained for prototype design and fabrication. It is suggested that increasing forcing magnitude or choosing forcing frequency greater than the natural frequency of its inner mass can benefit the average speed of the capsule, and the radius of the capsule should be slightly larger than the radius of the small intestine in order to generate a reasonable resistance for capsule progression. Finally, the locomotion of the capsule along an inclined intestinal tract is tested, and the best radius and forcing magnitude of the capsule are also determined.Engineering and Physical Sciences Research Council (EPSRC)National Natural Science Foundation of ChinaInternational S&T Cooperation and Exchanges of Sichuan provinceFundamental Research Funds for the Central Universitie