Control system design of duct cleaning robot capable of overcoming L and T-shaped ducts

This study introduces the control method of duct cleaning robot that enables real-time position tracking and self-driving over L-shaped and T-shaped duct sections. The developed robot has three legs and is designed to flexibly respond to duct sizes. The position of the robot inside the duct is identified using the UWB communication module and the location estimation algorithm. Although UWB communication has relatively large distance error within the metal, the positional error was reduced by introducing appropriate filters to estimate the robot position accurately. TCP/IP communication allows commands to be sent between the PC and the robot and to receive live images of the camera attached to the robot. Using Haar-like and classifiers, the robot can recognize the type of duct that is difficult to overcome, such as L-shaped and T-shaped duct, and it moves successfully inside the duct according to the corresponding moving algorithms.

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.

Consequences of Stenting and Endoscopic Papillary Balloon Dilatation in Treatment of Large and Multiple Common Bile Duct Stones

BACKGROUND Although stenting for the treatment of large and multiple common bile duct stones has been acceptable to everyone, its efficacy and outcome have not been studied in comparison with other endoscopic procedures. The purpose of this study was to compare the consequences of stenting and endoscopic papilla balloon dilatation for the treatment of large and multiple common bile duct stones. METHODS In a double-blind clinical trial, of 431 patients with bile duct stones referred to the treatment center, 64 patients with multiple common bile duct stones ( ≥ 3) and more than 15 cm were selected for the study, then by random allocation rule the participants were allocated in two groups. They were entered into two different endoscopic papillary balloon dilatation (EPBD) and common bile ducts stenting treatments so that both procedures were performed by a person. Both groups were assessed from the point of views therapeutic outcomes such as duct cleaning, pancreatitis, isolated pain, and duct rupture. Data were collected by a self-made questionnaire that was used before and after the procedure to obtain the needed information. Then data were analyzed using SPSS software version 22 and descriptive and analytical tests were used as appropriated. RESULTS Although the duct cleaning and the complete removal of the stones in the stenting treatment procedure was 93.8%, and in EPBD was 78.3%, no significant difference was observed between the two groups (p = 0.14). Pancreatitis significantly increased after the first and second endoscopic retrograde cholangiopancreatography (ERCP) in the stent group compared with EPBD (p = 0.02). Also, the most frequent cases of isolated pain were in the endoscopic group EPBD (p = 0.0). However, the occurrence of perforation after first ERCP and EPBD was zero, but in the second stage of ERCP, 3.3% of the patients had perforations (p = 0.99). The results indicated that the shape of the stone (circular and angled) was not effective in the result of treatment in the two groups. CONCLUSION The results of this study indicated that in case of experience and skill in conducting the ERCP, common bile duct stenting is still the first line of treatment for large and multiple stones of the common bile ducts.

A Task-Space Tracking Control Approach for Duct Cleaning Robot Based on Fuzzy Wavelet Neural Network

In this study, a task-space adaptive robust control methodology which takes uncertainties and external disturbances into account is proposed for a class of duct cleaning mobile manipulators. First of all, the configuration of the real duct cleaning robot is introduced, and the Jacobian matrix and the dynamic model of the real robotic system are obtained. Then, the structure of adaptive robust controller based on sliding mode control (SMC) approach and the fuzzy wavelet neural network is detailed, the proposed control approach combines the advantages of SMC which can suppress the external disturbances with the fuzzy wavelet neural network which can compensate the uncertainties by its strong ability to approximate a nonlinear function to an arbitrary accuracy, the stability of the whole robotic control system, the uniformly ultimately boundedness of tracking errors, and the boundedness of fuzzy wavelet neural networks weight estimation errors are all guaranteed based on the Lyapunov stability theory. Finally, simulation results are presented to demonstrate the superior performance of the proposed approach, and experiments are given to illustrate that the proposed approach is useful for real duct cleaning robot system with well performance.

Advanced Backstepping Trajectory Control for Skid-Steered Duct-Cleaning Mobile Platforms

In recent years, a novel skid-steered duct-cleaning mobile platform was developed to remove dust accumulated on the inner surface of an air-ventilation duct with its rolling brushes. During the cleaning process, the irregular brushing pressure acting on the upper arm makes it difficult to control the platform through the duct path. In fact, the repulsive external force due to the brushing pressure is not directly measurable or computable because of the nonlinear deformation of the brush. In addition, dynamic uncertainties in platform motion can occur during reciprocating motion of the upper arm. Therefore, a model-based trajectory-tracking controller is required to control the mobile cleaning platform by considering irregular external forces. The robustness of the developed controller based on the adaptable PD(Proportional-Derivative)-backstepping method has been proposed and evaluated through numerical analysis and experiments. For the turning motion in a narrow space, a skid-steered platform model considering wheel slippage has been also implemented. The result shows that tracking control can be successfully achieved under various conditions of frequencies in brushing-arm motion and torque limitation of the traction motors.