Tapered, Twisted Bundled-Tube Locomotive Devices for Stepped Pipe Inspection

The twisted bundled-tube locomotive device is an elongated soft robot that moves inside a pipe in a helical bending motion. This motion mimics the behavior of microorganisms called spirochetes. This device is inexpensive and easy to miniaturize because of its simple structure, which consists of three inflatable tubes twisted together. It can move in pipes of various diameters without a change in design. Therefore, it has a high capacity for water pipe inspection. However, it has not yet been shown to pass through step parts wherein the diameter of the pipes decreases. In this study, we developed a device that was deformed into a tapered shape by changing the pitch of the spirals at each location. The prototype device was able to move from a pipe with an inside diameter of 52.9 mm to a pipe with an inside diameter of 21.6 mm for horizontally fixed pipes, and from a pipe with an inside diameter of 41.6 mm to a pipe with an inside diameter of 21.6 mm for vertically fixed pipes.

Specific Problems in Measurement of Coefficient of Friction Using Variable Incidence Tribometer

The subject of this paper is the solution to specific problems in the measurement of the coefficient of the sliding friction of material pairs using a variable incidence tribometer. The aim of this work was to solve the questions of the measurement of the static coefficient of friction using a variable incidence tribometer from the perspective of metrology. In particular, we intended to research the expression of the credibility of this measurement and the possibility of increasing the credibility of the measurement. Another problem that needs to be solved is the method of carrying out the measurement, which has an impact on its achieved uncertainty. Sliding friction is a phenomenon that depends on many material properties such as contact area roughness, moisture, lubricants, temperature, and relative motion velocity. If environmental conditions are defined, the main input parameter is the relative motion velocity. For this input quantity, friction force becomes a symmetrical problem, and it is only necessary to explore this phenomenon for positive values of velocities. Symmetry in this area simplifies the research of this science topic.

Development of a vision-based target exploration system for snake-like robots in structured environments

Applying snake-like robots to environmental exploration has been a hot topic for years. How to achieve free navigation for target search in a complex environment in a safe and efficient manner is one of the main tasks that researchers in the field of robotics currently face. This article presents a target exploration system that takes advantages of visual sensing to navigate the snake-like robot in structured environments. Two cameras are utilized in the system. The first one is mounted on the head of the snake-like robot for target recognition and the other is an overhead camera which is responsible for locating the robot and identifying surrounding obstacles. All dead ends in the environment can thus be recognized using a template-based method. A search strategy for traversal of the dead ends is employed for generating exploration paths. Several gaits are developed for the snake-like robot. By switching between these gaits, the snake-like robot is able to follow the paths to search for the target. Two experiments are conducted in a maze environment. The experimental results validate the effectiveness of the proposed system for snake-like robots exploring in structured environments.

Investigation of Snake Robot Locomotion Possibilities in a Pipe

This paper analyzed the locomotion of a snake robot in narrow spaces such as a pipe or channel. We developed a unique experimental snake robot with one revolute and one linear joint on each module, with the ability to perform planar motion. The designed locomotion pattern was simulated in MATLAB R2015b and subsequently verified by the experimental snake robot. The locomotion of the developed snake robot was also experimentally analyzed on dry and viscous surfaces. The paper further describes the investigation of locomotion stability by three symmetrical curves used to anchor static modules between the walls of the pipe. The stability was experimentally analyzed by digital image correlation using a Q-450 Dantec Dynamics high-speed correlation system. The paper presents some input symmetrical elements of locomotion and describes their influence on the results of locomotion. The results of simulations and experiments show possibilities of snake robot locomotion in a pipe.

Development of a Peristaltic-Movement Duct-Cleaning Robot for Application to Actual Environment - Examination of Brush Type and Installation Method to Improve Cleaning Efficiency –

This paper describes a method to increase both the cleaning performance and speed of a peristaltic duct-cleaning robot, besides the cleaning of a real house duct. Duct piping ventilation is an important component for safeguarding indoor human health. However, dust accumulates inside such ducts during long-term use of ventilation systems. This dust leads to the generation of bacteria, dispersal of which can cause serious human health problems. Therefore, it is necessary to clean such ducts. The ducts used in factories, for example, have a large cross-sectional area and so are easy to clean by conventional duct-cleaning methods. However, as housing ducts have a small cross-sectional area and many curves, they are difficult to clean via the passive method of inserting a cleaning tool through the duct ports. For this reason, the authors attempted to develop a method of duct cleaning using a robot that imitates the peristaltic movement of earthworms. Herein, the authors examine the type and mounting position of the cleaning brush that produces the optimum cleaning efficiency. From this, we confirmed the duct cleanability of the peristaltic robot.

Driving Mechanisms, Motion, and Mechanics of Screw Drive In-Pipe Robots: A Review

In recent years, interest in in-pipe robot research has been steadily increasing. This phenomenon reflects the necessity and urgency of pipe inspection and rehabilitation as several pipe networks have become outdated around the globe. In-pipe robots can be divided into several groups in accordance with their locomotion principles, each with its own advantages and best suited application scope. Research on the screw drive in-pipe robot (SDIR) has had a rising trend due to the robot’s simple driving mechanism design and numerous advantages. This study compares and analyzes the characteristics of various SDIRs from the aspects of mechanism design, driving principle, and motion and mechanical behaviors. Each SDIR has its own advantages and disadvantages depending on its design requirements and intended applications. A number of prototypes have been fabricated to verify their functionality and efficiency in inspection tasks. This study can provide an up-to-date reference for researchers to conduct further analysis on SDIRs.

Influence of pipe geometric deviation on bristled in-pipe mobile robot locomotion

This article deals with the analysis of geometric deviations influence on in-pipe robot locomotion, which uses the principle of friction difference principle. Bristles are as carrying elements. They are mounted as cantilever beams at angle to robot body. The robot should locomote inside industrial pipelines. All pipes have geometric deviations, which come from production process otherwise from operation process. It is necessary to know about the influence of these geometric deviations on the robot locomotion.