Cable Robot Research Articles

Research on key technologies of multi-task-oriented live maintenance robots for Ultra High Voltage multi-split transmission lines

Purpose The purpose of this study is to solve the key technical problems of the practical application of electric robots. The UHV multi-split transmission line power cable operation robot is an important equipment to ensure the reliable operation of high voltage lines and is a useful exploration to realize high-quality power transmission. As the robot system platform equipment mature and operation environment gradually become more complex, the double arm coordination motion control in extreme environment becomes one of the main bottleneck for its practical in power system. Design/methodology/approach This paper summarizes the key technologies related to power cable robots, and aims at key technical indicators such as operation reliability, operation efficiency and operation quality in the robot’s practical process. The dynamic evolution mechanism of the robot’s mechanical configuration, the multi-physics information fusion algorithm in extreme environments, the robot’s autonomous positioning and its error compensation control, the robot’s robust motion control in extreme environments and the dual-arm force-position hybrid coordination control and the dynamic distribution and elimination mechanism of internal forces in the closed chain between robots and operating objects, all the research methods and solutions of the key technologies are proposed, respectively. Findings Finally, a new control architecture for power cable robots in the background of the Ubiquitous Power Internet of Things is proposed so as to manage the operation and maintenance of electric power systems. The above key technologies are a new exploration of the operation and maintenance management of EHV (Extra High Voltage) multi-split transmission lines which have laid a solid theoretical foundation for the power cable robot. Originality/value High voltage transmission line is the main channel of power transmission. It is an important means to improve the integration of operation and maintenance management of power system to use robot instead of manual inspection and maintenance of power line, in the promotion and application of electric robot. The authors pay attention to the practicability, and the breakthrough of key technologies of robot is the premise of the practicability of robot. In this paper, the robot operation and control in multi-task and complex scenes are studied. The research and implementation of the main key technologies, such as the dynamic evolution mechanism of robot configuration, the coupling and fusion law of multi physical fields in the extreme electric power environment, the autonomous positioning control of manipulator, the robust control of robot in the super electromagnetic field environment and the cooperative operation control of multi manipulator, are discussed.

Cable robot design method using the NX CAD / CAM / CAE system

The article describes a method for designing a cable robot used for moving goods under special conditions. It is a parallel structure mechanism using the NX CAD / CAM / CAE system controlled by the Teamcenter PLM system. The mechanism is a rigidly fixed frame connected by tensioned ropes to a platform containing an axial displacement device. The diagram of the device is presented. To develop an electronic-digital model of the robot, the control structure that allowed for designing using the “Top-Down” method was built. The control structure reduces time required to develop a model. The spatial parameters of the device were determined. The product concept was developed.

Workspace Enlargement of Cable-Based Haptic Device Using Linear Actuator

Haptic displays have been attracting attention for several decades and a broad range of devices have been developed to allow interaction with virtual objects. Among these, cablebased architectures were researched in order to overcome the lack of flexibility and the intrusiveness inherent to rigid haptic displays. Cable robots allow the utilization of several end effectors, which can be proved to be particularly useful for providing haptic rendering on several fingers for the bimanual manipulation of virtual objects. Nonetheless, interference can appear when cables touch each other during manipulation. Also, some configurations may require a high number of cables to make full use of the frame of the device. Here, we propose a novel architecture of a haptic display based on SPIDAR. Our purpose is to enlarge the usable workspace of an existing device configuration while lowering the number of cables and without hindering the quality of the display. A hybrid planar haptic device architecture with n+1 cables that includes a linear module is introduced. Design considerations and the kinematics used are detailed. Then, simple tasks are performed to verify the usability of the device as a haptic display.

Discussion on Applicability and Requirements for the Installation of Fastenings Using Robot Systems in the Construction Industry

Since robotics is becoming increasingly widespread in the construction industry, more phases and working steps should be investigated for their applicability to automation. Ideally, only few robot systems would be needed and thus be multifunctional.Current robot systems are used almost exclusively in precast construction. At the construction site, only prototypes are in use, and only individual parts of the building shell construction and assembly can be handled.This paper examines to what extent robots can be applied for the installation of fastenings and which boundary conditions exist or need to be addressed. Automated construction, and more precise installation of fastenings, has been partially implemented, which has been shown to increase productivity as well as installation quality, and therefore the components’ structural safety. This knowledge must now be extended to robots. The present work is based on an overview of current research and development and includes a discussion on the current research at the University Duisburg-Essen on a cable robot for brickwork construction. It further demonstrates that fastenings pose an important additional application, especially to ensure the changeover to other building materials. These can be built-in parts, but also brickwork connections or prefabricated parts.It can be assumed that robots will become increasingly important in the construction industry for reasons that include high quality, safety, speed and economic aspects.This is an extended paper of the Creative Construction Conference in Budapest on “Examination of Advanced Fastening Systems for the use of Robots in the Construction Industry” (Spyridis et al., 2019).

Dynamic trajectory planning of reconfigurable suspended cable robot

This paper focuses on the dynamic trajectory planning of reconfigurable suspended cable robot. By using the approach of the dynamic equilibrium of suspended cable robot, a set of constraint equations are derived. These equations represent the cable tensions in terms of the cable directions, moving-platform payload and the instantaneous position of the moving-platform. While fulfilling the dynamic equilibrium, the position of cable contact points are reconfigured thanks to the pulley mechanism. Through the pulley reconfiguration, the robot may adapt its tension to be always positive while executing the task for a given trajectory. Two robot structures will be compared for various parametric trajectories. A prototype has been fabricated for both robot structures to demonstrate the tension distributions along the trajectory.

A Vision-Based Referencing Procedure for Cable-Driven Parallel Manipulators

Abstract In the last three decades, cable-driven parallel robots (CDPRs) have captured a growing attention in the robotics field. Indeed, they promise to bring automation in fields where it is not affirmed yet, granting ease of scaling and reconfigurability. For large-workspace cable robots, accuracy is an important issue. In this paper, a look-and-move procedure is proposed, based on a wireless camera, to refer the coordinate frame of the CDPR platform to another known coordinate frame. Two sample cases are studied and presented. In the first, the proposed vision-based system is employed to let the platform precisely attain its home position. In the second, the platform is referenced to an external coordinate frame, in order to accurately accomplish an assigned task. For both cases, experiments are successfully carried out.

Deflection Maps of Planar Elastic Catenary Cable-Driven Robots

Abstract In this paper, the cable tension and platform deflection of cable-driven robots are studied. The significance of cable density, elasticity, and cross-sectional area; platform mass, radius, and center of mass; the external wrench and platform orientation on the cable tension, platform deflection, and workspace of the planar cable robots is investigated. It is shown that, in addition to the cable mass, external wrench has a more prominent effect on the workspace of the catenary cable model. Moreover, design issues and parameters affecting the manipulator deflection are examined, and those that would result in disjointed workspace regions and deflection maps are identified. It is presented that the change in the deflection is gradual throughout the workspace for a constant external wrench. For the catenary model, depending on the cable properties, platform orientation, manipulator design, and external wrench, the workspace with the deflection limit may consist of disconnected regions.

Robust motion control for multi-split transmission line four-wheel driven mobile operation robot in extreme power environment

PurposeIn the multi-splitting transmission lines extreme power environment of ultra-high voltage and strong electromagnetic interference, to improve the trajectory tracking and stability control performance of the robot manipulator when conduct electric power operation, and effectively reduce the influence of disturbance factors on the robot motion control, this paper aims to presents a robust trajectory tracking motion control method for power cable robot manipulators based on sliding mode variable structure control theory.Design/methodology/approachThrough the layering of aerial-online-ground robot three-dimensional control architecture, the robot joint motion dynamic model has been built, and the motion control model of the N-degrees of freedom robot system has also been obtained. On this basis, the state space expression of joint motion control under disturbance and uncertainty has been also derived, and the manipulator sliding mode variable structure trajectory tracking control model has also been established. The influence of the perturbation control parameters on the robot motion control can be compensated by the back propagation neural network learning, the stability of the controller has been analyzed by using Lyapunov theory.FindingsThe robot has been tested on a analog line in the lab, the effectiveness of sliding mode variable structure control is verified by trajectory tracking simulation experiments of different typical signals with different methods. The field operation experiment further verifies the engineering practicability of the control method. At the same time, the control method has the remarkable characteristics of sound versatility, strong adaptability and easy expansion.Originality/valueThree-dimensional control architecture of underground-online-aerial robots has been proposed for industrial field applications in the ubiquitous power internet of things environment (UPIOT). Starting from the robot joint motion, the dynamic equation of the robot joint motion and the state space expression of the robot control system have been established. Based on this, a robot closed-loop trajectory tracking control system has been designed. A robust trajectory tracking motion control method for robots based on sliding mode variable structure theory has been proposed, and a sliding mode control model for the robot has been constructed. The uncertain parameters in the control model have been compensated by the neural network in real-time, and the sliding mode robust control law of the robot manipulator has been solved and obtained. A suitable Lyapunov function has been selected to prove the stability of the system. This method enhances the expansibility of the robot control system and shortens the development cycle of the controller. The trajectory tracking simulation experiment of the robot manipulator proves that the sliding mode variable structure control can effectively restrain the influence of disturbance and uncertainty on the robot motion stability, and meet the design requirements of the control system with fast response, high tracking accuracy and sound stability. Finally, the engineering practicability and superiority of sliding mode variable structure control have been further verified by field operation experiments.

Model-Based Control of a Pendulum by a 3-DoF Cable Robot Using Exact Linearization

Abstract In this paper we present the modeling and control of a pendulum by a cable robot. The control is based on an exact linearization of the nonlinear MIMO system. The resulting closed-loop system is subsequently extended by a pendulum damping. The pose of the pendulum is determined by the connection point of the cables at the pendulum and a reflector at the end of the pendulum. Due to the model-based control and the capability of an external absolute measurement of the reflector by means of laser trackers, a high positioning accuracy is achievable, which is unique in the field of cable robots.

Adaptive robust control of a four-cable-driven parallel robot

This present study introduces an adaptive control strategy for four-cable robots. An adaptive sliding mode control to overcome the uncertainties of the system as well as avoidance of estimating an upper bound of the system uncertainties is presented. The proposed controller is designed based on the Lyapunov stability theory. Therefore, it ensures the stability of the closed-loop system and makes the tracking error converge to zero. In this robot, the cables can only pull the end-effector but not push it; therefore, we present a simple mathematical solution to design a positive tension controller for the cable suspended robot with redundant cables. The properties of the proposed method such as high performance tracking, disturbance rejection and insensitivity to parameter variations are demonstrated by simulation.

Design of High-speed Cable Driven Robot with Unlimited Rotation of Hand

Design of High-speed Cable Driven Robot with Unlimited Rotation of Hand

Design Dynamic Models for Cable Robot Spraying Pesticides in Agricultural Production

Design Dynamic Models for Cable Robot Spraying Pesticides in Agricultural Production

A Path Planning Optimization Framework for Concrete Based Additive Manufacturing Processes

Concrete based Additive Manufacturing (AM) is an emerging technological sector including numerous potential application fields, varying from buildings to facades and furniture. Path planning optimization of Concrete based AM is considered as a milestone, towards further automation and utilization of the technology. The current study presents a modular framework for the holistic multi-level optimization of path planning for concrete AM. Steps are described in detail and include strategies for the selection of a near optimum path and selection of acceptable process parameters, along with controlling actions of a cable robot based concrete AM process head. Also, following outcomes derived from the path strategy, an appropriate building block geometry is generated through design successive approximations. These building blocks fulfil (mechanical and thermal) functional requirements as well as they meet buildability criteria, with emphasis on minimizing idle times. Finally, a software platform supporting the aforementioned activities has been implemented and is presented herein. It provides an interface based on Web-Services, achieving portability of data and functionalities.

On the movement of the rope robot on a vertical surface

A method of moving a cable robot on a vertical surface with support on it is considered. The motion of the robot with adjustable, with the help of the load, the position of the center of mass is investigated. The stages of overcoming obstacles by such a robot and the equations of motion at individual stages of movement are described.

Design-to-Workspace Synthesis of a Cable Robot Used in Legs Training Machine

SUMMARYThis paper deals with a continuous design task of a planar cable robot used in a gait training machine called the cable-driven legs trainer. The design of cable robots requires satisfying two constraints, that is, tensions in the cables must remain non-negative, and cable interferences should be avoided. The carried design approach is based on interval analysis, which is one of the most efficient methods to obtain certified results. The constraints of non-negative tensions and cable to end-effector interference are solved using interval analysis tools. By means of a dynamic simulation, the reached workspace and the produced wrenches of the cable robot are evaluated as a set of interval vectors. An optimization algorithm is then designed to optimize the cable robot structure for the gait training machine. The robot is designed to produce non-negative tensions in the cables and to avoid collision at all times within the desired workspace and under the required external loads.

Optimal Control of a Wheeled Mobile Cable-Driven Parallel Robot ICaSbot with Viscoelastic Cables

SUMMARYIn this paper, a new mobile cable-driven parallel robot is proposed by mounting a spatial cable robot on a wheeled mobile robot. This system includes all the advantages of cable robots such as high ratio of payload to weight and good stiffness and accuracy while its deficiency of limited workspace is eliminated by the aid of its mobile chassis. The combined system covers a vast workspace area whereas it has negligible vibrations and cable sag due to using shorter cables. The dynamic equations are derived using Gibbs–Appell formulation considering viscoelasticity of the cables. Therefore, the more realistic viscoelastic cable model of the robot reveals the system flexibility effect and shows the requirements needed to control the end-effector in the conditions with cable elasticity. The viscoelastic system stability is investigated based on the input–output feedback linearization and using only the actuators feedback data. Feedback linearization controller is equipped by two additional controllers, that is, the optimal controller based on Linear Quadratic Regulator (LQR) method and finite horizon model predictive approach. They are used to control the system compromising between the control effort and error signals of the feedback linearized system. The applied control input to the robot plant is the voltage signal limited to a specified band. The validity of modeling and the designed controller efficiency are investigated using MATLAB simulation and its verification is accomplished by experimental tests conducted on the manufactured cable robot, ICaSbot.

СТРУКТУРНЫЙ АНАЛИЗ И КЛАССИФИКАЦИЯ РОБОТИЗИРОВАННЫХ СИСТЕМ С ПРИВОДНЫМИ МЕХАНИЗМАМИ НА ОСНОВЕ КАБЕЛЬНЫХ ЭЛЕМЕНТОВ

The mechanisms of the parallel structure are very diverse. Cable-driven robots that use cables instead of retractable rods to control the position of the output link are of particular interest. They have several advantages, such as large workspace, easy assembly, and disassembly, high mobility, but also there are disadvantages associated with controlling the movement of robot cables. The paper gives examples of some of the first cable robots, their purpose, and application. The article also considers Russian and foreign scientists who deal with these issues and analyzes their work. As a result of the structural analysis, the classification of cable robots is compiled and considered in detail: by the method of placing the reels, by the DOF number of the working body and the number of flexible links, by the application method, by the type of base, by the method of cable fastening. The cable robot structure for the movement of goods is given. However, there are still many areas open to theoretical research. In conclusion, the topics that need more research are considered. The most obvious area of research is control, also optimizing the workspace for different applications of these devices, finding and take advantage of all the benefits offered by cable devices.

American Society of Biomechanics Journal of Biomechanics Award 2018: Adaptive motor planning of center-of-mass trajectory during goal-directed walking in novel environments

To aid in the successful execution of goal-directed walking (discrete movement from a start location to an end target) the central nervous system forms a predictive motor plan. For the motor plan to be effective, it must be adapted in response to environmental changes. Despite motor planning being inherent to goal-directed walking, it is not understood how the nervous system adapts these plans to interact with changing environments. Our objective was to understand how people adapt motor plans of center of mass (COM) trajectory during goal-directed walking in response to a consistent change in environmental dynamics. Participants preformed a series of goal-directed walking trials in a novel environment created by a cable robot that applied a lateral force field to their COM. We hypothesized that participants would adapt to the environment by forming an internal model of their COM trajectory within the force field. Our findings support this hypothesis. Initially, we found COM trajectory significantly deviated in the same direction as the applied field, relative to baseline (no field) (p = 0.002). However, with practice in the field, COM trajectory adapted back to the baseline (p = 0.6). When we unexpectedly removed the field, participants demonstrated after-effects, COM trajectory deviated in the direction opposite of the field relative to baseline (p < 0.001). Our findings suggest that when performing a goal-directed walking task, people adapt a motor plan that predicts the COM trajectory that will emerge from the interaction between a specific set of motor commands and the external environment.

Live maintenance robot for high-voltage transmission lines

Purpose The purpose of this paper is to improve the operation and maintenance intelligence of power systems, and summarize the transmission line robots and their key technologies. High-voltage power cables are important channels for power transmission systems. Their special geographical environment and harsh natural environment can lead to many different faults. At present, such special operations in dangerous and harsh environments are performed manually, which have not only high labor intensity and low work efficiency but also great personal safety risks. Design/methodology/approach For maintenance works that are far away from the tower, power outages are required. With the increasing evaluation of transmission quality and operational safety, and the urgent need for automation and operation of modern power systems, the contradiction between this manual operation and modern high-quality power transmission has become increasingly prominent. An effective method to replace the manual maintenance work is to use the mobile robot to carry the operation manipulator and its end tool, that is, the live maintenance robot. Findings Some achievements have been made in the key technologies of live maintenance robots, the work to be done to meet the basic requirements of complex and changeable line environment and practical application. Based on the existing research results of live overhaul robot, the follow-up research will focus on the practical application needs and the frontier of scientific and technological development, and truly realize the human–machine integration between live overhaul robot–human working environment. Only in this way can the robot better serve the operation and maintenance of the power system. Originality/value This paper reviews the system platform, operation function, structural characteristics and key technologies involved in the power cable robot, and the combination of live maintenance robots and modern high-tech such as big data and cloud computing is also given, and finally, the future development direction of the special operation robot is pointed out.

Synchronous Position Control of Robotics System for Infrastructure Inspection Moving on Rope Tether

Most bridges, tunnels, dams, and other infrastructure facilities were constructed in the 1950s to 1960s. At present, aging in these facilities is a social problem. Most of the maintenance check-ups of these infrastructure facilities are manually conducted by close visual inspection, which has limitations. As a result, there have been many proposals on inspection systems for unmanned infrastructure facilities, such as drones and cable robots. However, there are also problems with the use of cable robots and drones, such as restrictions in places that they can be used and effects from the environment. Thus, this study proposes a robotics system for infrastructure inspection that solves such problems. Two robots move on parallel ropes stretching in an H shape, and one robot with a three-dimensional gimbal and camera moves on a rope stretching between those robots. At this time, the three robots are capable of efficient, highly accurate wide-ranging observation by carrying out synchronous position control using wireless communication. The control system has optimum synchronous position capabilities and uses a disturbance observer. Regarding this infrastructure inspection robotics system, this study discusses the development of three mobile robotics systems and the synchronous position control of two robots.