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Adhesion-based space climbing robots, with their flexibility and multi-functional capabilities, are seen as a promising candidate for in-orbit maintenance. However, challenges such as uncertain adhesion establishment, unexpected detachment, and body motion unsteadiness in microgravity environments persist. To address these issues, this paper proposes a coordinated force–position compliance control method that integrates novel adhesion establishment and rotational detachment strategies, integrated into the gait schedule for a space climbing robot. By monitoring the foot-end reaction forces in real time, the proposed method establishes adhesion without risking damaging the spacecraft exterior, and smooth detachment is achieved by rotating the foot joint instead of direct pulling. These strategies are dedicated to reducing unnecessary control actions and, accordingly, the required adhesion forces in all feet, reducing the possibility of unexpected detachment. Climbing experiments have been conducted in a suspension-based gravity compensation system to examine the merits of the proposed method. The experimental results demonstrate that the proposed rotational detaching method decreases the required pulling force by 65.5% compared to direct pulling, thus greatly reducing the disturbance introduced to the robot body and other supporting legs. When stepping on an obstacle, the compliant control method is shown to reduce unnecessarily aggressive control actions and result in a reduction in relevant normal and shear adhesion forces in the supporting legs by 44.8% and 35.1%, respectively, compared to a PID controller. [ABSTRACT FROM AUTHOR]

Effective adaptive grasping capability is regarded as crucial for climbing robots. However, many dry adhesion legged climbing robots are primarily focused on mobility and load capacity to perform various climbing tasks, often overlooking their operational grasping abilities. Furthermore, flexible grippers designed for adaptive grasping are typically not capable of supporting autonomous climbing or perching motions; they must be rigidly integrated with legged climbing robots, which results in increased weight and reduced load capacity. To address this challenge, a novel dry adhesion climbing robot, MST-G, is proposed, featuring autonomous climbing, perching, and flexible adaptive grasping capabilities. During operation, MST-G is integrated with a legged climbing robot to perform tasks, but can autonomously climb when no task is present, thereby reducing load and ensuring stable motion. Additionally, a robust controller based on prescribed performance is introduced and tested on MST-G, which limits the joint tracking error to a prescribed safety limit, ensuring that motion trajectories can be executed safely and reliably. [ABSTRACT FROM AUTHOR]

Dangers in aerial work will cause huge economic losses and casualties. To improve this problem, this paper designs a track climbing robot based on the Halbach square magnetic array, which can be used for the inspection and maintenance of large steel structures. First, the adsorption unit uses the Halbach square magnetic array to arrange permanent magnets. The loadbearing mechanism transfers the weight of the robot body to the track plate while sharing the load of two axes and assisting the track to stick to the wall. The tensioning mechanism is used to support the track. Then, the critical states of the two failure types of sliding and overturning of the climbing robot are analyzed, and the magnetic adsorption force provided by the single track plate required for the stable adsorption of the robot is determined; the two motion states of the robot, straight and turning, are analyzed, and the torque provided by the drive device required when the robot moves is determined. Finally, the adsorption force of the adsorption unit is calculated by COMSOL simulation; the axial and circumferential movement of the track along the curved surface is simulated and analyzed to verify the feasibility of the climbing robot. The results show that the robot can be stably adsorbed on the wall, the adsorption force of a single track shoe should be no less than 48.59N for the robot to move flexibly on the wall, and the driving torque provided by the drive device of the single-side track should be greater than 20.47N, the adsorption unit using N42 permanent magnet can bring an adsorption force of 27.812N. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Robots are becoming integral to society and industries due to their enormous advantages. Among the various categories of mobile robots, including wheeled robot, tracked robot, and legged robots, the latter stands out as a better choice for most field applications due to their adaptability across various terrains. The purpose of this review is to study the locomotion capabilities of quadruped robots and judge their suitability for climbing applications as most unexplored applications of automation and robotics are required to climb. This review explores the locomotion capabilities of quadruped robots. It covers different aspects of quadruped robots like types of legs, leg design, gait patterns, and their mathematical formulations, and types of motions like omnidirectional motion and body sway motion. It also emphasizes its fault-tolerant gait, adaptability, and reliability. The paper also focuses on slope and stair climbing, outlining design requirements and applications. The study includes an examination of the applicability of various gaits under different conditions and the methods for increasing stability without compromising speed. Overall, the review serves as a valuable resource for future research in this field. [ABSTRACT FROM AUTHOR]

Climbing robots, with their expansive workspace and flexible deployment modes, have the potential to revolutionize the manufacturing processes of large and complex components. Given that the surfaces to be machined typically exhibit variable curvature, good surface adaptability, load capacity, and motion accuracy are essential prerequisites for climbing robots in manufacturing tasks. This paper addresses the manufacturing requirements of climbing robots by proposing an asymmetric independently steerable wheel (AISW) for climbing robots, along with the motion control method. Firstly, for the adaptability issue of the locomotion mechanism on curved surfaces under heavy load, an asymmetric independently steerable wheel motion module is proposed, which improves the steering difficulty of the traditional independently steerable wheel (ISW) based on the principle of steering assisted by wheels. Secondly, a kinematic model of the AISW chassis is established and, on this basis, a trajectory tracking method based on feedforward and proportional–integral feedback is proposed. Comparative experimental results on large, curved surface components show that the asymmetric independently steerable wheel has lower steering resistance and higher motion accuracy, significantly enhancing the reachability of climbing robots and facilitating their application in the manufacturing of large and complex components. [ABSTRACT FROM AUTHOR]

Adhesion-based space climbing robots, with their flexibility and multi-functional capabilities, are seen as a promising candidate for in-orbit maintenance. However, challenges such as uncertain adhesion establishment, unexpected detachment, and body motion unsteadiness in microgravity environments persist. To address these issues, this paper proposes a coordinated force–position compliance control method that integrates novel adhesion establishment and rotational detachment strategies, integrated into the gait schedule for a space climbing robot. By monitoring the foot-end reaction forces in real time, the proposed method establishes adhesion without risking damaging the spacecraft exterior, and smooth detachment is achieved by rotating the foot joint instead of direct pulling. These strategies are dedicated to reducing unnecessary control actions and, accordingly, the required adhesion forces in all feet, reducing the possibility of unexpected detachment. Climbing experiments have been conducted in a suspension-based gravity compensation system to examine the merits of the proposed method. The experimental results demonstrate that the proposed rotational detaching method decreases the required pulling force by 65.5% compared to direct pulling, thus greatly reducing the disturbance introduced to the robot body and other supporting legs. When stepping on an obstacle, the compliant control method is shown to reduce unnecessarily aggressive control actions and result in a reduction in relevant normal and shear adhesion forces in the supporting legs by 44.8% and 35.1%, respectively, compared to a PID controller.

The gecko can achieve flexible climbing on various vertical walls and even ceilings, which is closely related to its unique foot adhesion system. In the past two decades, the mechanism of the gecko adhesion system has been studied in-depth, and a verity of gecko-inspired adhesives have been proposed. In addition to its strong adhesion, its easy detachment is also the key to achieving efficient climbing locomotion for geckos. A similar controllable adhesion characteristic is also key to the research into artificial gecko-inspired adhesives. In this paper, the structures, fabrication methods, and applications of gecko-inspired controllable adhesives are summarized for future reference in adhesive development. Firstly, the controllable adhesion mechanism of geckos is introduced. Then, the control mechanism, adhesion performance, and preparation methods of gecko-inspired controllable adhesives are described. Subsequently, various successful applications of gecko-inspired controllable adhesives are presented. Finally, future challenges and opportunities to develop gecko-inspired controllable adhesive are presented. [ABSTRACT FROM AUTHOR]

Robots are becoming integral to society and industries due to their enormous advantages. Among the various categories of mobile robots, including wheeled robot, tracked robot, and legged robots, the latter stands out as a better choice for most field applications due to their adaptability across various terrains. The purpose of this review is to study the locomotion capabilities of quadruped robots and judge their suitability for climbing applications as most unexplored applications of automation and robotics are required to climb. This review explores the locomotion capabilities of quadruped robots. It covers different aspects of quadruped robots like types of legs, leg design, gait patterns, and their mathematical formulations, and types of motions like omnidirectional motion and body sway motion. It also emphasizes its fault-tolerant gait, adaptability, and reliability. The paper also focuses on slope and stair climbing, outlining design requirements and applications. The study includes an examination of the applicability of various gaits under different conditions and the methods for increasing stability without compromising speed. Overall, the review serves as a valuable resource for future research in this field.

This paper focuses on the development of a novel climbing robot that is designed for autonomous maintenance of vertical gardens in urban environments. The robot, designed with a unique five-legged structure, is equipped with a range of electrical and mechanical components, enabling it to autonomously navigate and maintain a specially designed vertical garden wall facilitating interactive maintenance and growth monitoring. The motion planning and control of the robot were developed to ensure precise and adaptive movement across the vertical garden wall. Advanced algorithms were employed to manage the complex dynamics of the robot's movements, optimizing its efficiency and effectiveness in navigating and maintaining the garden structure. The operation of the robot in maintaining the vertical garden was evaluated during a two-week trial where the robot successfully performed nearly 8000 leg movements, with only 0.6% requiring human intervention. This demonstrates a high level of autonomy and reliability. This study concludes that the pentapod robot demonstrates significant potential for automating the maintenance of vertical gardens, offering a promising tool for enhancing urban green spaces. [ABSTRACT FROM AUTHOR]

This paper aims to introduce robot technology to carry out the safety inspection of transmission towers in long-distance power transmission, so as to improve the safety and efficiency of inspection. However, aiming at the problem that the existing climbing robots are mainly used for large load applications, which leads to the large size and lack of flexibility of the robot, we propose an innovative solution. Firstly, a lightweight quadruped climbing robot is designed to improve portability and operational flexibility. Then, a one-dimensional force sensor is added at the end of each leg of the robot, and a special swing phase trajectory is designed. The robot can judge whether the electromagnetic adsorption is effective and avoid potential safety hazards. Finally, based on the principle of virtual model control (VMC), a foot-end force balancing algorithm is proposed to achieve uniform distribution and continuous change in force, and improve safety and load capacity. The experiments show that the scheme has a stable climbing ability in the environments of angle steel, vertical ferromagnetic plane and transmission tower. [ABSTRACT FROM AUTHOR]

Climbing robots, with their expansive workspace and flexible deployment modes, have the potential to revolutionize the manufacturing processes of large and complex components. Given that the surfaces to be machined typically exhibit variable curvature, good surface adaptability, load capacity, and motion accuracy are essential prerequisites for climbing robots in manufacturing tasks. This paper addresses the manufacturing requirements of climbing robots by proposing an asymmetric independently steerable wheel (AISW) for climbing robots, along with the motion control method. Firstly, for the adaptability issue of the locomotion mechanism on curved surfaces under heavy load, an asymmetric independently steerable wheel motion module is proposed, which improves the steering difficulty of the traditional independently steerable wheel (ISW) based on the principle of steering assisted by wheels. Secondly, a kinematic model of the AISW chassis is established and, on this basis, a trajectory tracking method based on feedforward and proportional–integral feedback is proposed. Comparative experimental results on large, curved surface components show that the asymmetric independently steerable wheel has lower steering resistance and higher motion accuracy, significantly enhancing the reachability of climbing robots and facilitating their application in the manufacturing of large and complex components.

The inspection of high ceilings or surfaces is important to ensure the quality and safety of infrastructure; however, the approach adopted by people or conventional robots is rather limited. Kinodynamic constraints (simultaneous kinematic and dynamic constraints) are presented by obstacles in real-life scenarios, such as suspended piping and wiring, which further limits the usability of robots. Therefore, this paper proposed an adhesion robot system that is attached to and maneuvers on flat and curved ceilings while traversing obstructions. To traverse obstacles, the robot comprises two units connected by a passive hinge mechanism. Traversal motion is achieved under adhesion force control with preexisting electric ducted fans without using separate hinge motors; thus, no additional weight is included. In addition to robot hardware, this study investigated the development of a control method based on dynamic analysis under the aforementioned kinodynamic constraints. Specifically, the proposed control algorithm considers the slipping and rollover conditions of the robot caused by the external force and moment applied to the unit during the obstacle traversal, respectively. The algorithm was systematically analyzed by conducting simulations to prevent the robot from experiencing adhesion failure, and the results were verified experimentally. The use of the robot in real-life scenarios was determined by performing feasibility tests in real-life applications.

Force sensors on climbing robots give important information to the robot control system, however, off-the-shelf sensors can be both heavy and bulky. We investigate the optimisation of a lightweight integrated force sensor made of piezoelectric material for the multi-limbed climbing robot MAGNETO. We focus on three design objectives for this piezoelectric component. The first is to develop a lightweight component with minimal compliance that can be embedded in the foot of the climbing robot. The second objective is to ensure that the component has sensing capability to replace the off-the-shelf force sensor. Finally, the component should be robust for a range of climbing configurations. To this end, we focus on a compliance minimisation problem with constrained voltage and volume fraction. We present structurally optimised designs that satisfy the three main design criteria and improve upon baseline results from a reference component. Our computational study demonstrates that the optimisation of embedded robotic components with piezoelectric sensing is worthy of future investigation. [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. [ABSTRACT FROM AUTHOR]

Robotized intelligent manufacturing is a growing trend in the manufacturing of large and complex components in aviation, aerospace, marine engineering and other industries. With their expansive workspaces and flexible deployment, climbing manufacturing robots can create a revolutionary manufacturing paradigm for large and complex components. This paper defines the climbing manufacturing robot based on the application status of climbing robots and then analyzes four key technical requirements: adhesion, locomotion, localization and control. Subsequently, the current research status of climbing robots in these four areas is classified and reviewed, along with a clarification of the research frontiers and trends in each area, and the applicability of the relevant research to manufacturing-oriented climbing robotic systems is analyzed. Finally, by concluding the development trends of robotized intelligent manufacturing equipment in terms of manufacturing dimension and scale, environmental adaptability and cluster collaboration capability, we clarify the major challenges for climbing manufacturing robots in terms of adhesion principles, motion mechanisms, positioning technology and control methods, and propose future research directions in these fields. This review analyzes the current state and development trends of climbing manufacturing robots, and anticipates their significant contributions to the paradigm revolution of manufacturing large and complex components. [ABSTRACT FROM AUTHOR]

Climbing robots are designed to conduct tasks that may be dangerous for humans working at height. In addition to improving safety, they can also increase task efficiency and reduce labor costs. They are widely used for bridge inspection, high-rise building cleaning, fruit picking, high-altitude rescue, and military reconnaissance. In addition to climbing, these robots need to carry tools to complete their tasks. Hence, their design and development are more challenging than those of most other robots. This paper analyzes and compares the past decade's design and development of climbing robots that can ascend vertical structures such as rods, cables, walls, and trees. Firstly, the main research fields and basic design requirements of climbing robots are introduced, and then the advantages and disadvantages of six key technologies are summarized, namely, conceptual design, adhesion methods, locomotion modes, safety mechanisms, control methods, and operational tools. Finally, the remaining challenges in research on climbing robots are briefly discussed and future research directions are highlighted. This paper provides a scientific reference for researchers engaged in the study of climbing robots. [ABSTRACT FROM AUTHOR]

Easy detachment is as important as reliable an attachment to climbing robots in achieving stable climbing on vertical surfaces. To deal with the difficulty of detachment occurring in wheeled and track-type climbing robots using bio-inspired spines, a novel climbing robot utilizing spiny track and dual-rail mechanism is proposed in this paper. The spiny track consists of dozens of spiny feet, and the movement of each spiny foot is guided by the specially designed dual-rail mechanism to achieve reliable attachment and easy detachment. First, the design of the climbing robot and the dual-rail mechanism are presented. Then, the dual-rail model is constructed to analyze the attaching and detaching movements of the spiny feet, and a mechanical model is established to analyze the force distribution on the spiny track. Finally, a robot prototype is developed, and the analysis results are verified by the experiment results. Experiments on the prototype demonstrated that it could climb on various rough vertical surfaces at a speed of 36 mm/s, including sandpaper, brick surfaces, concrete walls with pebbles, and coarse stucco walls. [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. [ABSTRACT FROM AUTHOR]

This paper focuses on the development of a novel climbing robot that is designed for autonomous maintenance of vertical gardens in urban environments. The robot, designed with a unique five-legged structure, is equipped with a range of electrical and mechanical components, enabling it to autonomously navigate and maintain a specially designed vertical garden wall facilitating interactive maintenance and growth monitoring. The motion planning and control of the robot were developed to ensure precise and adaptive movement across the vertical garden wall. Advanced algorithms were employed to manage the complex dynamics of the robot’s movements, optimizing its efficiency and effectiveness in navigating and maintaining the garden structure. The operation of the robot in maintaining the vertical garden was evaluated during a two-week trial where the robot successfully performed nearly 8000 leg movements, with only 0.6% requiring human intervention. This demonstrates a high level of autonomy and reliability. This study concludes that the pentapod robot demonstrates significant potential for automating the maintenance of vertical gardens, offering a promising tool for enhancing urban green spaces.

Grass cutting is necessary to prevent grass from diverting essential nutrients and water from crops. Usually, in hilly and mountainous areas, grass cutting is performed on steep slopes with an inclination angle of up to 60° (inclination gradient of 173%). However, such grass cutting tasks are dangerous owing to the unstable positioning of workers. For robots to perform these grass cutting tasks, slipping and falling must be prevented on inclined surfaces. In this study, a robot based on stable propeller control and four-wheel steering was developed to provide stable locomotion during grass cutting tasks. The robot was evaluated in terms of locomotion for different steering methods, straight motion on steep slopes, climbing ability, and coverage area. The results revealed that the robot was capable of navigating uneven terrains with steep slope angles. Moreover, no slipping actions that could have affected the grass cutting operations were observed. We confirmed that the proposed robot is able to cover 99.95% and 98.45% of an area on a rubber and grass slope, respectively. Finally, the robot was tested on different slopes with different angles in hilly and mountainous areas. The developed robot was able to perform the grass cutting task as expected. [ABSTRACT FROM AUTHOR]

This paper aims to introduce robot technology to carry out the safety inspection of transmission towers in long-distance power transmission, so as to improve the safety and efficiency of inspection. However, aiming at the problem that the existing climbing robots are mainly used for large load applications, which leads to the large size and lack of flexibility of the robot, we propose an innovative solution. Firstly, a lightweight quadruped climbing robot is designed to improve portability and operational flexibility. Then, a one-dimensional force sensor is added at the end of each leg of the robot, and a special swing phase trajectory is designed. The robot can judge whether the electromagnetic adsorption is effective and avoid potential safety hazards. Finally, based on the principle of virtual model control (VMC), a foot-end force balancing algorithm is proposed to achieve uniform distribution and continuous change in force, and improve safety and load capacity. The experiments show that the scheme has a stable climbing ability in the environments of angle steel, vertical ferromagnetic plane and transmission tower.

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

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.

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.

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.

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]