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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.

Purpose In the long-term network operation, the power distribution network will be subjected to the effects of ultra-high voltage, strong electromagnetic interference and harsh natural environment on the power system, which will lead to the occurrence of different faults in the distribution network and directly affect the normal operation of the power grid. Design/methodology/approach The purpose of this study is to solve the problems of labor intensity, high risk and low efficiency of distribution network manual maintenance operation, this paper proposed a new configuration of the live working robot for distribution network maintenance, the robot is equipped with dual working arms through the mobile platform, which can realize the coordination movement, the autonomous reorganization and replacement of the end tools, respectively, so as the robot power distribution maintenance function such as stripping, trimming, wiring and the operation control problem of the distribution network-robot with small arms and in small operation space can be realized. Findings To effective elimination or reduce the adverse effects of the internal forces in the closed chain between the working object and manipulator under the typical task of the 10 kV distribution network, this paper has established the robot coordinated control dynamics model in the closed-chain between the dual-working object and proposed the dynamic distribution method of closed-chain internal force and the effectiveness has been proved by simulation experiments and 10 kV field operation. Originality/value The force-position hybrid control can realize the mutual compensation of force and position so as to effectively reduce the internal force in the closed chain. Finally, the engineering practicality of the method is verified by field operation experiment, the effective implementation of this control method greatly improves the robot working efficiency and the operation reliability, the promotion and application of the control method have great theoretical and practical value and maintenance management system, so as to achieve automation of electric.

Purpose The purpose of this paper is to achieve optimal climbing control of the gas-insulated switchgear (GIS) robot, as the authors know that the GIS inspection robot is a kind of artificial intelligent mobile equipment which auxiliary or even substitute human labor drive on the inner wall of the gas-insulated metal enclosed switchgear. The GIS equipment fault inspection and maintenance can be realized through the robot manipulator on the mobile platform and the camera carried on the fuselage, and it is a kind of intelligent equipment for operation. To realize the inspection and operation of the GIS equipment pipeline without blind spots, the robot is required to be able to travel on any wall inside the pipeline, especially the top of the pipeline and both right and left sides of the pipeline, which requires the flexible climbing of the GIS inspection robot. The robot device has a certain adsorption function to ensure that the robot is fully attached to the wall surface. At the same time, the robot manipulator can be used for collision-free obstacle avoidance operation planning in the narrow operation space inside the GIS equipment. Design/methodology/approach The above two technologies are the key that the robot completes the GIS equipment inspections. Based on this, this paper focuses on modeling and analysis of the chassis adsorption characteristics for the GIS inspection robot. At the same time, the Denavit Hartenberg (D-H) coordinate model of the robot arm system has been established, and the kinematics forward and inverse solutions of the robot manipulator system have been derived. Findings The reachable working space point cloud diagram of the robot manipulator in MATLAB has been obtained based on the kinematics analysis, and the operation trajectory planning of the robot manipulator using the robot toolbox has been obtained. The simulation results show that the robot manipulator system can realize the movement without collision and obstacle avoidance. The space can cover the entire GIS pipeline so as to achieve no blind area operation. Originality/value Finally, the GIS inspection robot physical prototype system has been developed through system integration design, and the inspection, maintenance operation experiment has been carried out in the actual GIS equipment. The entire robot system can complete the GIS equipment inspection operation soundly and improve the operation efficiency. The research in this paper has important theoretical significance and practical application value for the optimization design and practical research of the GIS inspection robot system.

Purpose In 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/approach Through 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. Findings The 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/value Three-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.

Purpose This study aims to the three major problems of low cleaning efficiency, high labor intensity and difficult to evaluate the cleaning effect for manual insulators cleaning in ultra high voltage (UHV) converter station, the purpose of this paper is to propose a basic configuration of UHV vertical insulator cleaning robot with multi-freedom-degree mechanical arm system on mobile airborne platform and its innovation cleaning operation motion planning. Design/methodology/approach The main factors affecting the insulators cleaning effect in the operation process have been analyzed. Because of the complex coupling relationship between the influencing factors and the insulators cleaning effect, it is difficult to establish its analytical mathematical model. Combining the non-linear mapping and approximation characteristics of back propagation (BP) neural network, the insulator cleaning effect evaluation can be abstracted as a non-linear approximation process from actual cleaning effect to ideal cleaning effect. An evaluation method of robot insulator cleaning effect based on BP neural network has been proposed. Findings Through the BP neural network training, the robot cleaning control parameters can be obtained and used in the robot online operation control, so that the better cleaning effect can be also obtained. Finally, a physical prototype of UHV vertical insulator cleaning robot has been developed, and the effectiveness and engineering practicability of the proposed robot configuration, cleaning effect evaluation method are all verified by simulation experiments and field operation experiments. At the same time, this method has the remarkable characteristics of sound versatility, strong adaptability, easy expansion and popularization. Originality/value An UHV vertical insulator cleaning robot operation system platform with multi-arm system on airborne platform has been proposed. Through the coordinated movement of the manipulator each joint, the manipulator can be positioned to the insulator strings, and the insulator can be cleaned by two pairs high-pressure nozzles located at the double manipulator. The influence factors of robot insulator cleaning effect have been analyzed. The BP neural network model of insulator cleaning effect evaluation has been established. The evaluation method of robot insulator cleaning effect based on BP neural network has also been proposed, and the corresponding evaluation result can be obtained through the network training. Through the system integration design, the robot physical prototype has been developed. For the evaluation of other operation effects of power system, the validity and engineering practicability of the robot mechanism, motion planning and the method for evaluating the effect of robot insulator cleaning have been verified by simulation and field operation experiments.

Purpose The power cable maintenance robot is an important equipment to ensure the reliable operation of high-voltage transmission (HVT) lines and is a useful exploration to achieve high-quality power transmission. In respond to a series of technical problems in the operation process, such as robot shaking, terminal positioning error, camera image blurred and visual servo control difficulty which caused by the influence of high altitude random wind load on the motion control of power maintenance robot. The purpose of this study is to minimizing the impact of wind loads on robot motion control on the high voltage transmission line, so as to obtain the sound motion performance. Design/methodology/approach This paper presents a robust stabilization control method for flexible wire power maintenance robot under wind load action, the coupling mathematical model between the flexible wire with the robot has been established, and the robot rolling model under wind load has also been established. According to the tilt sensor, the robot pendulum angle value can be obtained and fitted through sinusoidal function; the robot swing period and frequency under wind load action can be also obtained; the feedforward- and feedback-based robot closed-loop control system is also designed. Findings Through the online detection of wind load dection, so as to dynamic control the clamping force of the robot's dual-arm jaws, therefore, the robot robust stabilization control with different grades of wind load can be realized. Finally, the effectiveness and engineering practicability of the proposed algorithm are verified by simulation experiments and field operation experiments. Compared with the conventional proportional integral differential (PID) algorithm, this method can effectively suppress the influence of wind load on the robot robust stabilization motion control, and the robot posture detection operation control has been further optimized. Originality/value A robust stabilization control method for power robot under wind load is proposed. The coupling motion model of flexible HVT and robot is established. The mathematical relationship between the robot wind rolling angle and the wind force has been deduced, and the corresponding closed-loop control system with feedforward and feedback has also been designed. Through the design of robust stabilization control algorithm based on mixed sensitivity function, the effectiveness of the mixed sensitivity robust stabilization control algorithm is verified by simulation experiments in MATLAB environment. Compared with the traditional PID algorithm, this method can effectively suppress the influence of large-scale disturbance information represented by wind load on the robot motion control. The engineering practicability of the robot robust stabilization control algorithm is further verified by the robot live damper replacement operation under the field wind load, which further improves the robot operation efficiency and intelligence.

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.

Purpose In the extreme power environment of flexible transmission line, wind load, high voltage and strong electromagnetic interference, the motion performance of the robot manipulator is strongly affected by the extreme environment. Therefore, this study aims to improve the manipulator motion control performance of power cable maintenance robot and effectively reduce the influence of specific operation environment on the robot manipulator motion posture. Design/methodology/approach The mathematical model under three typical operation conditions, namely, flexible line, wind load and strong electromagnetic field have been established, correspondingly the mapping relationship between different environment parameters and robot operation conditions are also given. Based on the nonlinear approximation feature of neural network, a back propagation (BP) neural network is adopted to solve the posture control problems. The power cable line sag, robot tile angle caused by wind load and spatial field strength are the input signals of the BP network in the robot motion posture control method. Findings Through the training and learning of the BP network, the output control variables are used to compensate the actual robot operation posture. The simulation experiment verifies the effectiveness of the proposed algorithm, and compared with the conventional proportional integral differential (PID) control, the method has high real-time performance and sound stability. Finally, field operation experiments further validate the engineering feasibility of the control method, and at the same time, the proposed control method has the remarkable characteristics of sound universality, adaptability and easy expansion. Originality/value A multi-layer control architecture which is suitable for smart grid platform maintenance is proposed and a robot system platform for network operation and maintenance management is constructed. The human–machine–environment coordination and integration mode and intelligent power system management platform can be realized which greatly improves the intelligence of power system management. Mathematical models of the robot under three typical operation conditions of flexible wire wind load and strong electromagnetic field are established and the mapping relationship between different environmental parameters and the robot operation conditions is given. Through the non-linear approximation characteristics of BP network, the control variables of the robot joints can be obtained and the influence of extreme environment on the robot posture can be compensated. The simulation results of MATLAB show that the control algorithm can effectively restrain the influence of uncertain factors such as flexible environment, wind load and strong electromagnetic field on the robot posture. It satisfied the design requirements of fast response, high tracking accuracy and good stability of the control system. Field operation tests further verify the engineering practicability of the algorithm.

Purpose To improve the operational efficiency and intelligence of live operation robots in dynamic-unstructured operation environments, this paper aims to propose a fuzzy logic-based method for the autonomous search and visual localization control of a manipulator end effector applied to a drainage plate bolt on a high-voltage transmission line. The proposed approach is based on a four-way video image information output from a dual-operation manipulator. Design/methodology/approach First, based on the structural characteristics of the drainage line, an autonomous search method for the drainage plate bolt and a mapping relationship between the autonomous search control parameters and the relative posture of the operation manipulator-drainage line are proposed. The posture control parameters of the dual manipulators can then be obtained, and a two-dimensional fuzzy controller is designed with the posture offset distance and the posture offset angle as its input signals. This enables the localization control of the bolt and nut alignment to be realized through a visual process. Findings The proposed fuzzy control algorithm is used for bolt location control, and its performance is compared with that of the conventional approach. The simulation results indicate that the fuzzy control algorithm greatly improves the localization accuracy and operational efficiency of live operation robots. Originality/value Field operation experiments on actual transmission lines verify that the fuzzy control-based visual localization control of the robot manipulator has great engineering practicality. Therefore, the proposed method further improves operational intelligence compared with conventional algorithms.

Purpose In the high-altitude, high-voltage electromagnetic interference operation environment, due to the parameters perturbation for robot control model caused by uncertainties and disturbances, and with the poor effective of the conventional proportional–integral–derivative (PID) control to parameters perturbation system, the mathematical model of power cable live operation robot joint PID closed-loop control system is established. Design/methodology/approach The corresponding joint motion robust PID control method is also proposed based on Kharitonov theory, the system robust stability conditions including the sufficient and necessary conditions are deduced and obtained and the solving process of robust PID control parameters stability region is provided. Findings Finally, the simulation research on robot joint motion PID control system is also launched in MATLAB environment based on Kharitonov theory. The results show that the conventional PID control obtains better control effect only to nominal model but is ineffective to parameter perturbation system, while robust PID obtains sound control effect to parameter perturbation system. Compared with H8 robust PID, the Kharitonov robust PID has better control effect which meet the system design requirements of joint motor quickly response, high tracking accuracy and sound stability. Finally, the validity and engineering practicability are verified by 220-kV living replacing damper operation experiment. Originality/value This paper has described the development of a damper replacement power cable live maintenance robot experimental prototype, which greatly improves operation efficiency and deals with the safety problem of operation in a high-voltage environment. A general manipulator motion control model of the power cable robot is established; the Kharitonov theory-based parameter perturbation robust motion control method of damper replacement robot is also obtained. Through the simulation comparison, it is verified that the Kharitonov control has more superiority for dealing with the parameter perturbation systems under the premise of ensuring the stability motion. The field experiment has further confirmed the engineering practicability.

Purpose In response to the poor reliability of live maintenance robots in semi-structured environments and the difficulty of monitoring their operation status, this paper aims to propose an online method for evaluating the operation status of high-voltage live maintenance robots based on fuzzy control. Design/methodology/approach The robot bolt tightening operation is taken as an example. During the whole operation process, the key technologies of bolt tightening are analyzed theoretically, a two-dimensional fuzzy control model of bolt tightening process control is established and the control parameters, which characterize the operation status, are obtained. Through dynamic adjustment of the fuzzy controller, real-time online monitoring of the robot operation status can be achieved. Findings The results of simulation experiments and 220 kV live operation experiments show that the reliability of robot bolt tightening is greatly enhanced by the proposed control method. Originality/value The results not only verify the engineering practicability of the fuzzy control-based method but also indicate that it can improve efficiency, safety and operability.