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Regular maintenance of wire rope is considered the key to ensuring the safe operation of a sluice gate. Along these lines, in this work, a six-wheeled wire rope climbing robot was proposed, which can carry cleaning and maintenance tools for online cleaning and safety inspection of the sluice wire rope, without its disassembly. The developed climbing robot is composed of separable driving and driven trolleys. It adopts the spring clamping mechanism and the wheeled movement method. Thus, it can easily adapt to the narrow working environment and different diameter ranges of the sluice wire rope. In addition, the designed six-wheeled wire rope climbing robot not only possesses a simple structure, simple control, and stable climbing speed, which are typical characteristics of wheeled climbing robots, but also a large contact area with objects and small wheel deformation, which are typical characteristics of crawler climbing robots. Structural design and mechanical analysis were also carried out, with the fabrication of a prototype robot system called WRR-II. From the acquired experimental results of the prototype's climbing speed test, load capacity test, climbing adaptability test, and obstacle-negotiation ability test, the rationality and feasibility of the designed climbing robot scheme were verified. [ABSTRACT FROM AUTHOR]

In our previous works, we focused on the advantages of a passive mechanism in realizing autonomous robots, and we developed a multi-legged robot that climbs unknown vertical walls with uneven surfaces. In this study, we improve on our previous robot to broaden its workable area to include vertical pipes and corner walls. To demonstrate the effectiveness of the developed robot, experiments that included climbing uneven walls, corner walls, a large pipe, and parallel small pipes were conducted. Our results confirmed that the developed robot could climb in these environments. We conclude that the proposed mechanism is effective for climbing such unknown complex environments. The proposed robot is expected to be used in the inspection of large-scale infrastructures. [ABSTRACT FROM AUTHOR]

The stable operation of climbing robots exposed to high winds is of great significance for the health-monitoring of structures. This study proposes an anole lizard-like climbing robot inspired by its superior wind resistance. First, the stability mechanism of the anole lizard body in adhesion and desorption is investigated by developing adhesion and desorption models, respectively. Then, the hypothesis that the anole lizard improves its adhesion and stability performance through abdominal adjustment and trunk swing is tested by developing a simplified body model and kinematic model. After that, the structures of the toe, limb, and multi-stage flexible torso of the anole lizard-like climbing robot are designed. Subsequently, the aerodynamic behavior of the proposed robot under high-speed airflow are investigated using finite element analysis. The results show that when there is no obstacle, the climbing robot generates the normal force to enhance toepad friction and adhesion by tuning the abdomen's shape to create an air pressure difference between the back and abdomen. When there is an obstacle, a component force is obtained through periodic oscillation of the spine and tail to resist the frontal winds resulting from the vortex paths generated by the airflow behind the obstacle. These results confirm that the proposed hypothesis is correct. Finally, the adhesion and wind resistance performance of the anole lizard-like climbing robot is tested through the developed experimental platform. It is found that the adhesion force is equal to 50 N when the pre-pressure is 20 N. Further, it is shown that the normal pressure of the proposed robot can reach 76.6% of its weight in a high wind of 14 m/s. [ABSTRACT FROM AUTHOR]

With the development of robot technology and the extensive application of robots, the research on special robots for some complex working environments has gradually become a hot topic. As a special robot applied to transmission towers, the climbing robot can replace humans to work at high altitudes to complete bolt tightening, detection, and other tasks, which improves the efficiency of transmission tower maintenance and ensures personal safety. However, it is mostly the ability to autonomously locate in the complex environment of the transmission tower that limits the industrial applications of the transmission tower climbing robot. This paper proposes an intelligent positioning method that integrates the three-dimensional information model of transmission tower and visual sensor data, which can assist the robot in climbing and adjusting to the designated working area to guarantee the working accuracy of the climbing robots. The experimental results show that the positioning accuracy of the method is within 1 cm. [ABSTRACT FROM AUTHOR]

Standing tree pruning in fast-growing forests is an essential part of the targeted nurturing of quality fast-growing forests. Because of the high risk and low efficiency of traditional pruning methods, a climbing and pruning robot was developed, its design was optimized, and related experimental research was carried out. This paper describes the design scheme of the Monkeybot mechanical structure and control system and theoretically analyzes the clamping mechanism, walking mechanism, cutting mechanism, and obstacle avoidance mechanism to determine the critical design parameters. On the premise of ensuring a good pruning effect, Ansys Workbench Gui Explicit Dynamics was used for the cutting simulation experiment. The test adopts a three-factor and three-level orthogonal test method to explore the best design parameter combination when reducing the maximum shear stress on branches. A forest work performance evaluation was carried out using prototypes designed with the best variety of parameters. The forest test results show that the Monkeybot could prune trees with a diameter at breast height of 10~20 cm, the average operation time for pruning a tree was less than 30 s, the winter pruning effect was ideal, the maximum climbing height could reach 7.18 m, and the maximum pruning diameter could reach 2.79 cm. The development of the machine can provide equipment support for the research of fast-growing forest standing tree pruning and nurturing technology. [ABSTRACT FROM AUTHOR]

Regular inspection and maintenance can ensure safe working conditions of transport pipelines without leakage and damage. Pipeline-climbing robots can be used for rapid inspection of pipelines, effectively reducing labor costs and time consumption. For the annular pipelines outside spherical tanks, the special distribution and installation form presents more high obstacles, and puts forward higher requirements for the robot's climbing performance and obstacle-surmounting ability. An elastic obstacle-surmounting pipeline-climbing robot with composite wheels is proposed in this paper. The designed elastic shock-absorbing suspension mechanisms and composite wheels were designed to increase the stability and obstacle-surmounting ability of the robot. The adjustable robot frame and rotating joint mechanisms allowed the robot to adapt to pipelines of different diameters and radians. Force analysis and simulation of obstacle surmounting by the robot were performed. Experiments were conducted on a 110-mm diameter pipeline to test the payload performance and obstacle-surmounting ability of the robot. With its elastic shock-absorbing suspension mechanisms, the pipeline-climbing robot could carry a 30 kg payload and stably climb the pipeline. The maximum height of obstacles surmounted by the composite wheels of the robot was 20 mm. In the process of surmounting obstacles, the velocity and inclination angle of the robot could remain relatively stable. This novel composite wheels and mechanisms can improve the performance of the pipeline-climbing robot and solve the problem of surmounting high obstacles. By carrying various equipment and instruments, the robot can promote the automated maintenance and inspection of complex pipelines. [ABSTRACT FROM AUTHOR]

Climbing robots play an essential role in performing inspection work in civil infrastructures. These tasks require autonomous robots with competitive costs and the ability to adapt to different types of environments. This article presents ROMERIN, a new concept of a modular legged climbing robot where each leg is an autonomous robotic module in terms of processing capacity, control, and energy. The legs are equipped with suction cups that allow the robot to adhere to different types of surfaces. The proposed design allows the creation of climbing robots with a different number of legs to perform specific inspection tasks. Although each of the legs acts as an independent robot, they have the ability to share information and energy. The proposed control concept enables the development of climbing robots with the ability to adapt to different types of inspection tasks and with resilience characteristics. This article includes a description of the mechatronic design, the kinematics of the seven degree-of-freedom robotic legs, including the adhesion system, and the architecture of the control and simulation system. Finally, we present experimental results to test the modularity concept, mechanical design, and electronics using a four-legged robot configuration. We analyze the performance of the gripping system in different situations on four different surfaces and the behavior of the control architecture for two different robot body trajectories. [ABSTRACT FROM AUTHOR]

Many organisms have attachment organs with excellent functions, such as adhesion, clinging, and grasping, as a result of biological evolution to adapt to complex living environments. From nanoscale to macroscale, each type of adhesive organ has its own underlying mechanisms. Many biological adhesive mechanisms have been studied and can be incorporated into robot designs. This paper presents a systematic review of reversible biological adhesive methods and the bioinspired attachment devices that can be used in robotics. The study discussed how biological adhesive methods, such as dry adhesion, wet adhesion, mechanical adhesion, and sub-ambient pressure adhesion, progress in research. The morphology of typical adhesive organs, as well as the corresponding attachment models, is highlighted. The current state of bioinspired attachment device design and fabrication is discussed. Then, the design principles of attachment devices are summarized in this article. The following section provides a systematic overview of climbing robots with bioinspired attachment devices. Finally, the current challenges and opportunities in bioinspired attachment research in robotics are discussed. [ABSTRACT FROM AUTHOR]

This article presents a generalizable, low computational cost, simple, and fast gravity compensation method for legged robots with a variable number of legs. It is based on the static problem, which is a reduction in the dynamic model of the robot that takes advantage of the low velocity of climbing robots. To solve it, we propose a method that computes the torque to be applied by each actuator to compensate for the gravitational forces without using the Jacobian matrix for the forces exerted by the end-effector and without using analytical methods for the gravitational components of the model. We compare our method with the most popular method and conclude that ours is twice as fast. Using the proposed gravity compensator, we present a torque-based PD controller for the position of the leg modules, and a body velocity control without dynamic compensation. In addition, we validate the method with both hardware and a simulated version of the ROMERIN robot, a modular legged and climbing robot. Furthermore, we compare our controller with the usual kinematic inverse controllers, demonstrating that the mean angular and linear error is significantly reduced, as well as the power requirements of the actuators.

Cleaning tasks for vertical structures, such as building façades and walls on construction sites, are dangerous; there is a high risk of fall accidents among workers engaged in such tasks. Hence, research on the automation of wall-cleaning tasks based on robotics technology has been actively conducted in recent years. However, existing wall-cleaning robots have limitations, such as poor mobility performance or the need for additional infrastructure for operation. In this article, we designed a novel rope-driven wall-cleaning robot Edelstro-M2 with two innovative characteristics. First, both vertical and horizontal movements on the wall are possible by implementing a dual rope climbing mechanism and parallel kinematics. Second, except for a rope fixing arrangement, additional infrastructure, such as winch and building management unit systems, is not required for operation. A prototype model was developed, and real-world experiments were conducted to verify the mobility and cleaning performance of the robot. In the experiment, the robot was controlled by manual remote control. We plan to study automatic control of the robot in the future works. [ABSTRACT FROM AUTHOR]

In this paper, a new robotic gripper is proposed and modeled which is able to bear a high amount of load and it can be used as the claws of climbing robots. As the climbing robots are usually heavy and their configuration should be kept in height against the gravity, firm grippers with no slippage possibility should be designed in order to guarantee the stability. The proposed new gripper is essentially required for the grip-based climbing robots which are heavy and are supposed to accomplish a specific operational task while they are grasping the pipe-shaped structures. The kinematic and quasi-static modeling of the proposed gripper is extracted and its related parameters are optimized to provide the maximum gripping force and the minimum slippage probability. Since these robust grippers are usually actuated by high torque motors, the reaction effect of the actuators force on the arm of the robot model is investigated here as a new study. Hence, the corresponding mechanical arm is also controlled, using a robust nonlinear controller to neutralize the destructive effect of extreme reaction forces or torques from the gripper motors to the robot arm during its mission. Thus, a robust controller is designed and implemented on the arm joint to cover the required positioning accuracy of the arm movement during the climbing motion. Afterward, the applicability of the proposed gripper and also the efficiency of the designed controller is verified by the aid of some analytic and comparative simulation scenarios performed in MATLAB-SIMULINK and MSC-ADAMS simulation. It is shown that the proposed gripper together with its related controlling algorithm for the arm can successfully provide a proper climbing mechanism for these kinds of robots which are supposed to climb through the structures and perform a special manipulating task.

Due to lack of temporary falling protection device，the power transmission tower climbing robot is needed to research and developto replace the first climbing personnel to guarantee their safety.According to actual working environment and its functional requirements，a climbing robot model based on bionic silkworm characteristics is proposed in combination with bionic principles.The structure of the robot is designed and the adsorptionstability in the climbing process is analyzed. The kinematic model of the robot is established and the working space is simulated to verify the rationality of the robot structure.The physical prototype is manufactured and the relevant climbing experiments are carried out，the experimental results showing that the robot can replace the personnel to climb the tower.

Periodic inspections are required for the safe operation of large pressure vessels such as spherical tanks. Inspection robots have been applied in large pressure vessels due to their low cost and high efficiency. This paper presents a robotic system for the inspection of spherical tanks, which can identify and track weld lines on the shortest running route. Two‐dimensional (2D) weld maps were prepared for robot path planning on the basis of the actual distribution of weld lines. In 2D weld maps, indispensable repetitive lines were added to form an Eulerian circuit that traversed all weld lines. In addition, an improved Fleury algorithm was proposed to solve Eulerian circuit and plan an optimal running route for robot inspection. To accurately identify weld lines, deep learning networks were constructed and trained with weld line data sets, which were captured by the camera mounted in the front of the robot. The laboratory experiments indicated that the inspection robot could identify weld lines within 0.2–0.25 s and track weld lines with a maximum offset of ±20 mm. The experiment results demonstrated that the robot could plan the shortest path to traverse all weld lines on the experimental platform. In the field tests, the virtual simulation of weld path planning on spherical tanks was explored in detail. The field tests of a spherical tank (3000 m3) verified that the robotic system could improve the efficiency and stability of inspection operations and replace manual inspection with automated weld line recognition and weld path planning. [ABSTRACT FROM AUTHOR]

The emergence of renewable energy offers opportunities for academia and the industry to conduct scientific research and innovative technological developments on wind turbine climbing robots. These robots were developed to carry out specialized application tasks, such as in-situ inspection and maintenance of wind turbine physical structure. This paper presents a scaled-down prototype design of a climbing robot for wind turbine maintenance and its kinematic modeling. The winding mechanism is the key feature for providing enough adhesion force to support the climbing robot and needs to adapt to the different diameters of the wind turbine tower, as it climbs through a circular truncated cone shape. A climbing model is then considered, using four mecanum wheels for maneuverability of the different movement states up-down, rotation, and spiral as it climbs the wind turbine tower. The design of the wind turbine climbing robot was modeled in SketchUp and the motion states were implemented in MATLAB for the climbing performance capabilities of the driving wheels of the robot. Based on the theoretical results of motion characteristics, the scaled-down prototype design of a climbing robot possesses maneuverability of motion and is able to predict the robot's performance. The contribution of this paper is intended to provide a basis for the new transformative climbing robot design and effectiveness of the mecanum wheel for robot motion. [ABSTRACT FROM AUTHOR]

Forestry monitoring and high-voltage cable inspection demand on low-cost climbing robots. The proposed climbing robot has simple control and low cost, enabling loaded, which drives by a single motor. Based on the overrunning spring clutch mechanisms, two motions of holding and climbing are realized by one motor. A rope-driven gripper is for adaptive enveloping holding effectively and a thron wheel is used to attach the climbing surface and stable climbing. The design parameters of the overrunning spring clutch mechanism and the rope-driven gripper are determined. The prototype and experiment setup are built. The enveloping holding experiment is carried out to verify the holding stability and shape adaptability of the rope-driven gripper. The trunk and pipe climbing experiments verify the climbing performance of the climbing robot and its application prospects with a certain load. In the future, as a low-cost climbing robot, a camera or operating mechanism can be equipped for tasks. [ABSTRACT FROM AUTHOR]

Wall-climbing robots have been well-developed for storage tank inspection. This work presents a backstepping sliding-mode control (BSMC) strategy for the spatial trajectory tracking control of a wall-climbing robot, which is specially designed to inspect inside and outside of cylindrical storage tanks. The inspection robot is designed with four magnetic wheels, which are driven by two DC motors. In order to achieve an accurate spatial position of the robot, a multisensor-data-fusion positioning method is developed. The new control method is proposed with kinematics based on a cylindrical coordinate system as the robot is moving on a cylindrical surface. The main purpose is to promote a smooth and stable tracking performance during inspection tasks, under the consideration of the robot’s kinematic constraints and the magnetic restrictions of the adhesion system. The simulation results indicate that the proposed sliding mode controller can quickly correct the errors and global asymptotic stability is achieved. The prototype experimental results further validate the advancement of the proposed method; the wall-climbing robot can track both longitudinal and horizontal spatial trajectories stably with high precision.

This study introduces GLEWBOT (Gecko, Leech, and Woodpecker-inspired Robot), a cutting-edge, multispecies hybrid bioinspired robot engineered for inspecting exterior wall tiles. By integrating the adaptive locomotion techniques of leeches, the stability mechanisms found in gecko tails, and the percussive impact strategy of woodpeckers, GLEWBOT revolutionizes the inspection of wall surfaces. This innovative approach not only boosts inspection accuracy but also increases efficiency substantially. Constructed using 3D printing technologies, GLEWBOT combines lightweight design with structural integrity and integrates advanced microcontrollers for real-time, efficient inspection tasks. The robot features vacuum-based suction cup footpads for solid adhesion, minimizing detachment risks, and employs a compact machine learning model for instant on-site defect detection. This model, designed for edge computing, overcomes the hurdles of high computational demands. Additionally, GLEWBOT is equipped with an AI-powered acoustic recognition module, using a dedicated convolutional neural network (CNN) to assess tile integrity objectively. This significantly advances subjective manual inspections, offering a more reliable, objective analysis. Experimental trials involving systematic tapping across 26 tiles on a model wall validated GLEWBOT's defect detection capabilities. With an overall accuracy of 74.62%, precision of 75.4%, recall of 73.08%, and an F1-score of 74.22%, confirm GLEWBOT's potential as a reliable tool for identifying tile defects. Future work will focus on expanding GLEWBOT's versatility across different architectural materials and contexts while considering economic and regulatory factors for broader deployment. This research sets a new standard in robotic inspection for building maintenance and fosters interdisciplinary collaboration by illustrating the successful integration of bioinspired designs and artificial intelligence in structural inspections. • Growing concerns about exterior wall tile detachment pose a risk to public safety. • Introducing GLEWBOT, a specialized climbing robot designed to address these safety concerns. • GLEWBOT utilizes adhesive capabilities inspired by nature, incorporates AI-powered acoustic recognition, and advanced actuators for precision. • GLEWBOT offers promise as a tool for improved safety and accuracy in exterior wall tile inspections. [ABSTRACT FROM AUTHOR]

Transmission towers that support electric power fines are usually inspected manually by workers that climb them and visually inspect to find oxidation points. If oxidation is seen it must be repaired to ensure the integrity of the structure. This process is slow and dangerous for the workers. Due to the possibility of electrical shocks as well as falling from the structures that are around 50 meters high. In recent years the need to substitute human workers in hostile environments by equipments and robots that bring more safety in the realization of these tasks has arisen. In this paper, a bibliographic review of papers that presented conceptions of robots that can climb transmission towers and execute its inspection, search for oxi¬dation points and even do small maintenances is done. Through the use of a patent search methodology a preliminary and a detailed search were done, with a diversity of keywords about the subject as well as its combinations [1]. The preliminary search resulted in 2901 patents, which lead to the detailed search and finally culminated in the analysis of 164 patents, from which four showed technological potential to be analysed in this review.

Standing tree pruning in fast-growing forests is an essential part of the targeted nurturing of quality fast-growing forests. Because of the high risk and low efficiency of traditional pruning methods, a climbing and pruning robot was developed, its design was optimized, and related experimental research was carried out. This paper describes the design scheme of the Monkeybot mechanical structure and control system and theoretically analyzes the clamping mechanism, walking mechanism, cutting mechanism, and obstacle avoidance mechanism to determine the critical design parameters. On the premise of ensuring a good pruning effect, Ansys Workbench Gui Explicit Dynamics was used for the cutting simulation experiment. The test adopts a three-factor and three-level orthogonal test method to explore the best design parameter combination when reducing the maximum shear stress on branches. A forest work performance evaluation was carried out using prototypes designed with the best variety of parameters. The forest test results show that the Monkeybot could prune trees with a diameter at breast height of 10~20 cm, the average operation time for pruning a tree was less than 30 s, the winter pruning effect was ideal, the maximum climbing height could reach 7.18 m, and the maximum pruning diameter could reach 2.79 cm. The development of the machine can provide equipment support for the research of fast-growing forest standing tree pruning and nurturing technology.

Regular maintenance of wire rope is considered the key to ensuring the safe operation of a sluice gate. Along these lines, in this work, a six-wheeled wire rope climbing robot was proposed, which can carry cleaning and maintenance tools for online cleaning and safety inspection of the sluice wire rope, without its disassembly. The developed climbing robot is composed of separable driving and driven trolleys. It adopts the spring clamping mechanism and the wheeled movement method. Thus, it can easily adapt to the narrow working environment and different diameter ranges of the sluice wire rope. In addition, the designed six-wheeled wire rope climbing robot not only possesses a simple structure, simple control, and stable climbing speed, which are typical characteristics of wheeled climbing robots, but also a large contact area with objects and small wheel deformation, which are typical characteristics of crawler climbing robots. Structural design and mechanical analysis were also carried out, with the fabrication of a prototype robot system called WRR-II. From the acquired experimental results of the prototype’s climbing speed test, load capacity test, climbing adaptability test, and obstacle-negotiation ability test, the rationality and feasibility of the designed climbing robot scheme were verified.

Regular inspection and maintenance can ensure safe working conditions of transport pipelines without leakage and damage. Pipeline-climbing robots can be used for rapid inspection of pipelines, effectively reducing labor costs and time consumption. For the annular pipelines outside spherical tanks, the special distribution and installation form presents more high obstacles, and puts forward higher requirements for the robot’s climbing performance and obstacle-surmounting ability. An elastic obstacle-surmounting pipeline-climbing robot with composite wheels is proposed in this paper. The designed elastic shock-absorbing suspension mechanisms and composite wheels were designed to increase the stability and obstacle-surmounting ability of the robot. The adjustable robot frame and rotating joint mechanisms allowed the robot to adapt to pipelines of different diameters and radians. Force analysis and simulation of obstacle surmounting by the robot were performed. Experiments were conducted on a 110-mm diameter pipeline to test the payload performance and obstacle-surmounting ability of the robot. With its elastic shock-absorbing suspension mechanisms, the pipeline-climbing robot could carry a 30 kg payload and stably climb the pipeline. The maximum height of obstacles surmounted by the composite wheels of the robot was 20 mm. In the process of surmounting obstacles, the velocity and inclination angle of the robot could remain relatively stable. This novel composite wheels and mechanisms can improve the performance of the pipeline-climbing robot and solve the problem of surmounting high obstacles. By carrying various equipment and instruments, the robot can promote the automated maintenance and inspection of complex pipelines.

SUMMARY: Cable is the most important bearing structure of the cable-stayed bridges. Its safety has been of crucial public concern. Traditional manual cable inspection method has many defects such as low inspection efficiency, poor reliability and hazardous working environment. In this paper, a new wirelessly controlled cable-climbing robot enabling safe and convenient inspection of stay cables is proposed. The designed robot is composed of two modules, joined by four turnbuckles to form a closed structure that clasps the cable. The robot is controlled wirelessly by a ground-based station, and a DC power is supplied via an onboard lithium battery. The climbing principle and mechanical structure of this robot are introduced. The static model of the robot during obstacle negotiation is established. The relationships of the driving force and resistance with obstacle height to determine the obstacle-negotiation capability of the robot are obtained. The effects of cable diameter, cable inclination and preload force on obstacle climbing ability of the robot are also analyzed. The experiments verify that the robot could climb random inclined cables and overcome an obstacle of 2.42 mm in height with a mass of 5 kg payload. [ABSTRACT FROM AUTHOR]

This article presents the design and position-tracking control of a novel two-degree-of-freedom dual-rope winch robot. It is designed to be facilely installed at both corners of a building using two synthetic ropes and to move freely on the wall plane using the ropes to perform building maintenance work. This robot consists of a dual-rope winch system responsible for its movement on a plane and a thrust module that allows the robot to remain close to the wall through the force of the propeller. In the dual-rope winch system, ascending modules driven by two pulleys and connected by differential gears are arranged symmetrically; the position and posture on the plane can be determined by controlling the ropes. The robot winds a synthetic rope around the pulley to support the load with frictional force. Precise position control is difficult to implement because of the elasticity of the rope and the slip around the pulley. Therefore, in this article, a feedforward control to predict and compensate for the slip length of the rope and a proportional–integral controller to regulate the position error owing to the dynamic characteristics of the rope are proposed. Experiments to verify the performance of the controller for various trajectories were performed on the test bench. It was confirmed that the actual trajectory deviation is within 0.5% of the target trajectory. [ABSTRACT FROM AUTHOR]

This article proposes a new end-to-end deep super-resolution crack network (SrcNet) for improving computer vision–based automated crack detectability. The digital images acquired from large-scale civil infrastructures for crack detection using unmanned robots often suffer from motion blur and lack of pixel resolution, which may degrade the corresponding crack detectability. The proposed SrcNet is able to significantly enhance the crack detectability by augmenting the pixel resolution of the raw digital image through deep learning. SrcNet basically consists of two phases: phase I—deep learning–based super resolution (SR) image generation and phase II—deep learning–based automated crack detection. Once the raw digital images are obtained from a target bridge surface, phase I of SrcNet generates the corresponding SR images to the raw digital images. Then, phase II automatically detects cracks from the generated SR images, making it possible to remarkably improve the crack detectability. SrcNet is experimentally validated using the digital images obtained using a climbing robot and an unmanned aerial vehicle from in situ concrete bridges located in South Korea. The validation test results reveal that the proposed SrcNet shows 24% better crack detectability compared to the crack detection results using the raw digital images. [ABSTRACT FROM AUTHOR]

SUMMARY: Soft robots can perform effectively inspecting than rigid robots in some special environments such as nuclear pipelines and high-voltage cables. This article presents a versatile quadruped soft rod-climbing robot (SR-CR) that consists of four bending actuators and a telescopic actuator. The bending actuator is composed of flexible bellows with multiple folding air chambers, elastic telescopic layer (ETL), and strain-limiting layer (SLL). The telescopic actuator provides the energy for the robot to climb forward. The SR-CR is activated by a control strategy that alternates the body deformation and feet pneumatic clenched for stable climbing. The robot can climb rods at 90°, with the maximum speed of up to 2.33 mm/s (0.018 body length/s). At 0.83 HZ, the maximum moving speed of the robot in climbing horizontally parallel rods can reach 18.43 mm/s. In addition, the SR-CR can also achieve multiple impressive functions, including turning around a corner at a rate of 7 mm/s (0.054 body length/s), carrying a payload of 3.7 times its self-weight on horizontal rods at a speed of 9 mm/s (0.069 body length/s). [ABSTRACT FROM AUTHOR]

The evolution of the wind turbine to generate carbon-free renewable energy is rapidly growing. Thus, performing maintenance and inspection tasks in high altitude environments or difficult to access places, and even bad weather conditions, poses a problem for the periodic inspection process of the wind turbine industry. This paper describes the design and development of a scaled-down prototype climbing robot for wind turbine maintenance to perform critical tower operations. Thus, the unique feature of this maintenance robot is the winding mechanism, which uses a tension force to grip on the tower surface without falling to the ground either in static or dynamic situations, with the locomotion to perform a straight up–down motion in a circular truncated cone and the stability to work at significant heights. The robot computer-aided design (CAD) model of the mechanical mechanism, force and structural analysis, and the testing of the prototype model, are addressed in this paper. The key hardware developments that were utilized to build a low-cost, reliable and compact climbing robot are the embedded microprocessors, brushed DC motors, stepper motors and steel rope. This paper concludes with a successful preliminary experiment of a scaled down prototype proving the functionality of the concept. The potential applications for this robot are industrial maintenance, inspection and exploration, security and surveillance, cleaning, painting, and welding at extreme height conditions. [ABSTRACT FROM AUTHOR]

In view of the high risk and low efficiency of the manual maintenance of the safety rope during the work of the tower, the V-shaped angle steel symmetrical clamping mechanism is designed based on the principle of rhombus principle. It is mainly composed of a gripping hand, an abduction mechanism and an ejection mechanism. The clamping hand realizes the grasping of the diagonal steel by the cooperation of the screw jack and the sliding rail, and the abduction mechanism perpendicular to the clamping arm changes the position of the gripping hand by adjusting the exhibition distance thereof, and the V-shaped block on the front end of the ejector mechanism ensures that the robot body is always parallel to the angle. According to the analysis of the climbing environment of the transmission tower climbing robot, the three-dimensional model of the mechanism is drawn. The model is simplified according to the principle of rhombus principle and the rationality of the centering and the size of the mechanism is verified. The statics model is established and the clamping force is used for mechanical analysis and structural statics simulation. Through the prototype development and test, the feasibility of the clamping mechanism is preliminarily verified.

In this study, we present a novel neural control architecture for gait adaptation and obstacle avoidance of a tailless gecko robot. The control architecture is based on a hierarchical modular structure, consisting of several neural layers and modules. The first layer contains three sensory preprocessing modules which filter sensory noise and generate appropriate descending commands to activate corresponding behaviors through the second and third layers. The second and third layers contain a central pattern generator (CPG) module and CPG postprocessing modules, respectively. The CPG module generates basic rhythmic locomotion patterns, shaped by the CPG postprocessing modules to achieve different gaits (i.e., wave, intermediate, and trot) as well as different climbing directions (i.e., forward and sideways). We use a body inclination sensor to adapt the robot gait while climbing on different slope angles, with infrared sensors to detect an obstacle on its climbing path and activate obstacle avoidance behavior. We successfully tested our control approach on a real tailless gecko robot. As a result, the robot can efficiently climb forward on different slope angles (including 90∘) and automatically adapt its climbing gait accordingly, to maximize climbing speed and ensure stability. It can also avoid an obstacle by changing its climbing direction from forward to sideways. [ABSTRACT FROM AUTHOR]

In this paper, a new robotic gripper is proposed and modeled which is able to bear a high amount of load and it can be used as the claws of climbing robots. As the climbing robots are usually heavy and their configuration should be kept in height against the gravity, firm grippers with no slippage possibility should be designed in order to guarantee the stability. The proposed new gripper is essentially required for the grip-based climbing robots which are heavy and are supposed to accomplish a specific operational task while they are grasping the pipe-shaped structures. The kinematic and quasi-static modeling of the proposed gripper is extracted and its related parameters are optimized to provide the maximum gripping force and the minimum slippage probability. Since these robust grippers are usually actuated by high torque motors, the reaction effect of the actuators force on the arm of the robot model is investigated here as a new study. Hence, the corresponding mechanical arm is also controlled, using a robust nonlinear controller to neutralize the destructive effect of extreme reaction forces or torques from the gripper motors to the robot arm during its mission. Thus, a robust controller is designed and implemented on the arm joint to cover the required positioning accuracy of the arm movement during the climbing motion. Afterward, the applicability of the proposed gripper and also the efficiency of the designed controller is verified by the aid of some analytic and comparative simulation scenarios performed in MATLAB-SIMULINK and MSC-ADAMS simulation. It is shown that the proposed gripper together with its related controlling algorithm for the arm can successfully provide a proper climbing mechanism for these kinds of robots which are supposed to climb through the structures and perform a special manipulating task. [ABSTRACT FROM AUTHOR]

SUMMARY: In this paper, design, modeling, and control of a grip-based climbing robot are performed, which consists of a triangular chassis and three actuating legs. This robot can climb through any trusses, pipeline, and scaffolds structures and can perform any inspectional and operational tasks in the high height which decreases the falling danger of operation and increases the safety of the workers. The proposed robot can be substituted for the workers to decrease the risk of death danger and increase the safety of the operation. Since these kinds of infrastructures are truss shaped, the traditional wheel-based climbing robots are not able to travel through these structures. Therefore, in this paper, a grip-based climbing robot is designed to accomplish the climbing process through the trusses and infrastructures in order to perform inspecting and manipulating tasks. Hence, a proper mechanism for the mentioned robot is designed and its related kinematic and kinetic models are developed. Robot modeling is investigated for two different modes including climbing and manipulating phases. Considering the redundancy of the proposed robot and the parallel mechanism employed in it, the active joints are selected in a proper way and its path planning is performed to accomplish the required missions. Concerning the climbing mode, the required computed torque method (CTM) is calculated by the inverse dynamics of the robot. However, for the manipulation mode, after path planning, two controlling strategies are employed, including feedback linearization (FBL) and adaptive force control, and their results are compared as well. It is shown that the latter case is preferable since the external forces implemented on the end effector tool is not exactly predetermined and thus, the controller should adapt the robot with the exerted force pattern of the manipulator. The modeling correctness is investigated by performing some analytic and comparative simulation scenarios in the MATLAB and comparing the results with the MSC-ADAMS ones, for both climbing and manipulating phases. The efficiency of the designed controller is also proved by implementing an unknown force pattern on the manipulator to check its efficiency toward estimating the mentioned implemented forces and compensating the errors. It is shown that the designed robot can successfully climb through a truss and perform its operating task by the aid of the employed adaptive controller in an accurate way. [ABSTRACT FROM AUTHOR]

Underwater climbing robots have shown outstanding potential for cleaning underwater structures. Improvements in robotic intelligence can further facilitate their development in engineering applications. In this study, we propose a deep-learning-based biofouling recognition algorithm and a computer-vision-based boundary tracking method for an underwater cleaning robot (UCR) to achieve navigation. A Fast-SCNN network model accelerated by TensorRT was developed to accurately recognize areas covered by biofouling, achieving a fast processing speed of 0.03 s per image. Subsequently, a contour point extraction algorithm was introduced to obtain the biofouling boundary. Furthermore, a tracking cruise control method was developed to guide the robot for boundary tracking based on the position of the boundary relative to the robot. The experimental results demonstrated the capability of UCR to automatically recognize biofouling and track the boundary for automated cleaning operations. • TensorRT-optimized Fast-SCNN network can realize real-time biofouling recognition. • A contour points extraction algorithm is presented to locate biofouling boundary. • The robot is steered to track biofouling boundary by visual guidance. • Experimental results verify the feasibility of the algorithms and control method. [ABSTRACT FROM AUTHOR]

The emergence of renewable energy offers opportunities for academia and the industry to conduct scientific research and innovative technological developments on wind turbine climbing robots. These robots were developed to carry out specialized application tasks, such as in-situ inspection and maintenance of wind turbine physical structure. This paper presents a scaled-down prototype design of a climbing robot for wind turbine maintenance and its kinematic modeling. The winding mechanism is the key feature for providing enough adhesion force to support the climbing robot and needs to adapt to the different diameters of the wind turbine tower, as it climbs through a circular truncated cone shape. A climbing model is then considered, using four mecanum wheels for maneuverability of the different movement states up-down, rotation, and spiral as it climbs the wind turbine tower. The design of the wind turbine climbing robot was modeled in SketchUp and the motion states were implemented in MATLAB for the climbing performance capabilities of the driving wheels of the robot. Based on the theoretical results of motion characteristics, the scaled-down prototype design of a climbing robot possesses maneuverability of motion and is able to predict the robot’s performance. The contribution of this paper is intended to provide a basis for the new transformative climbing robot design and effectiveness of the mecanum wheel for robot motion.

The electroadhesion pad is mainly studied for applications, such as climbing robots and grippers. In this paper, we present our study with the confirmation of the adhesion properties of the electroadhesion pad with a double-insulating layer, pad modeling, and optimal design. Modeling and analysis consider the air layer generated during the manufacturing of both conventional single-insulated structures and dual-insulated structures. Through the finite element analysis simulation, the characteristics of the electroadhesion were verified, and modeling verification was performed, based on the variables that had a large influence as follows: applied voltage, electrode area, dielectric thickness, and permittivity. The electrode is made of aluminum, the substrate is made of silicon, and the dielectric is made of polyimide film. An error of up to 8.3% was found between the modeling and simulation. The optimization results were validated based on a pad applied to a climbing robot measuring 320×480mm² and weighing 2.8 kg. As a result, the optimal pad design resulted in an error of 7.3% between the modeling and simulation.

In this paper, we present a gecko-inspired soft robot that is able to climb inclined, flat surfaces. By changing the design of the previous version, the energy consumption of the robot could be reduced, and at the same time, its ability to climb and its speed of movement could be increased. As a result, the new prototype consumes only about a third of the energy of the previous version and manages to climb slopes of up to 84°. In the horizontal plane, its velocity could be increased from 2 to 6 cm/s. We also provide a detailed analysis of the robot's straight gait.