Patent Publication Number: US-2022214687-A1

Title: Unmanned aerial vehicle (uav)-assisted hanging ring robot for live installation and grounding

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation Application of PCT Application No. PCT/CN2021/136878 filed on Dec. 9, 2021, which claims the benefit of Chinese Patent Application No. 202011435695.8 filed on Dec. 10, 2020. All the above are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the technical field of auxiliary devices of a power system, and specifically, to an unmanned aerial vehicle (UAV)-assisted hanging ring robot for live installation and grounding. 
     BACKGROUND 
     A high-voltage ground wire is a kind of safety appliance for temporary short-circuit grounding of a power-off device, so as to prevent the device from being suddenly powered on again and prevent an induced voltage generated by an adjacent high-voltage live device from harming a human body during power-off maintenance or other operations for the high-voltage device, and discharge a residual charge of the power-off device. According to relevant power specifications, a ground clamp needs to be reserved and installed at an end, near a tower, of each conductor to facilitate ground wire lapping during maintenance. At present, many lines in operation are not equipped with ground clamps, and these ground clamps need to be manually installed when related devices are electrified. According to a current method for installing a ground clamp on a live conductor, after being transported to an end near the conductor by using an insulated bucket arm truck, an operator wears insulated shielding clothes, and installs the ground clamp by hand by using tools such as a clamp and a torque wrench. This method is affected by space and a high-altitude operation environment, and has a large difficulty coefficient. As a research and development subject, some manufacturers have developed a semi-automatic mechanical arm, which is transported to a position near the conductor by a person or a bucket arm truck for installation. 
     For example, the Chinese patent CN106737756A published on May 31, 2017 discloses a robot system for power inspection and ground wire operations based on a high-voltage distribution line. The robot system includes a robot body, and the robot body includes a mobile mechanism and a three degree of freedom mechanical operation arm that are connected to each other, and a control box installed on the robot body. The control box is internally equipped with a control unit, a first power module, and a first communication module. The first power module is connected to the control unit, the control unit is connected to a driving module, and the driving module is connected to the mobile mechanism and the three degree of freedom mechanical operation arm. The control unit is connected to a handheld control terminal and a ground control terminal by using the first communication module. The technical solution still needs to rely on a large auxiliary device, which makes it difficult and complex to perform an operation, and imposes a high requirement for the operator. 
     SUMMARY 
     The present disclosure is intended to resolve a technical problem that it is inconvenient to temporarily install a ground wire on an overhead conductor. The present disclosure provides a UAV-assisted hanging ring robot for live installation and grounding, to ground an overhead conductor conveniently with the help of a UAV. 
     To resolve the above technical problem, the present disclosure adopts the following technical solution: A UAV-assisted hanging ring robot for live installation and grounding is used together with a UAV, and includes a hanging tray, a wire hanging bracket, a hanging wire, an overturning stay wire, an overturning frame, a support, an electric lock, a walking wheel, a driving motor, a workbench, a clamp seat, a puncture clamp, a tightening mechanism, a remote controller, and a controller, where the hanging tray is installed at a bottom of the UAV, the wire hanging bracket is fixedly connected to the hanging tray, and the hanging wire is connected to wire hanging bracket; both the support and the clamp seat are installed on the workbench, the overturning frame is rotatably installed on the support, the electric lock is installed on the support, the overturning frame is provided with a lockhole matching the electric lock, one end of the overturning stay wire is connected to the overturning frame, the other end of the overturning stay wire hangs on ground, the walking wheel is rotatably installed on the overturning frame, the driving motor is installed on the overturning frame, and the walking wheel is connected to the driving motor; the puncture clamp is installed on the clamp seat, and the tightening mechanism is installed on the workbench and connected to a tightening screw of the puncture clamp; and the electric lock, the tightening mechanism, the driving motor, and the remote controller are connected to the controller. The hanging wire is lifted by the UAV, a lowest end of the hanging wire is raised to a position higher than a target conductor, and a descent height of the UAV is controlled, such that the hanging wire is located on one side of the target conductor. After that, the UAV is controlled to cross the target conductor and release the hanging wire, and the other end of the hanging wire falls to the ground under the action of gravity. One end of the hanging wire is connected to a hanging point of the robot, and the other end is pulled by an operator, to quickly raise the robot to below the target conductor. Then, the overturning frame installed with the walking wheel is overturned by using the overturning stay wire, and the hanging wire is continuously pulled to make the walking wheel higher than the target conductor. Then, the overturning stay wire is released, and the overturning frame recovers automatically. The walking wheel is stuck on the target conductor, and then the electric lock is locked. Driven by the walking wheel, the robot walks to a predetermined position along the target conductor. Finally, the tightening mechanism is started to drive the puncture clamp to close to connect the target conductor, and the puncture clamp is connected to a ground clamp in advance to ground the target conductor. 
     Preferably, the robot further includes a first wire hanging head and a second wire hanging head, where the hanging wire includes a first hanging wire and a second hanging wire, both ends of the wire hanging bracket are respectively connected to the first wire hanging head and the second wire hanging head, the first hanging wire is fixedly connected to the first wire hanging head, the second hanging wire is connected to the second wire hanging head, the workbench is provided with two wire hanging points, and a length of the wire hanging bracket corresponds to a distance between the two wire hanging points of the workbench. 
     Preferably, the wire hanging bracket includes a bushing, a left hanging rod, a right hanging rod, a left rack, a right rack, a driving gear, and a driving mechanism, the left hanging rod and the right hanging rod are sleeved on a left and a right of the bushing respectively, the left rack is fixedly connected to the left hanging rod, the right rack is fixedly connected to the right hanging rod, the driving gear is rotatably connected to the bushing, the driving mechanism is connected to the driving gear, both the left rack and the right rack are meshed with the driving gear, the left hanging rod is connected to the first wire hanging head, and the right hanging rod is connected to the second wire hanging head. The driving mechanism drives the driving gear to rotate, to drive the left rack and the right rack to move, such that extension elongations of the left hanging rod and the right hanging rod are changed to adjust the length of the wire hanging bracket to adapt to different robots. 
     Preferably, the driving mechanism includes a friction rod, a friction wheel, a fixed shaft, a driving pipe, a driving spring, a locking spring, and a locking ring, the fixed shaft is fixedly connected to the bushing, the driving gear is rotatably connected to the fixed shaft, the friction wheel is concentrically and fixedly connected to the driving gear, the driving pipe is fixedly connected to the bushing, the driving spring is installed in the driving pipe, one end of the friction rod is sleeved into the driving pipe, one end of the driving spring is fixedly connected to the driving pipe, the other end of the driving spring is fixedly connected to the friction rod, both ends of the driving spring are connected to an electronic switch K 1  and a direct current (DC) power supply BT 1  respectively by using wires, the friction rod is abutted with the friction wheel, the friction wheel is hollow and provided with an opening at one end away from the driving gear, one end, close to the driving gear, of the friction wheel is provided with a locking hole, the locking ring is sleeved on the fixed shaft, the fixed shaft is provided with a clamping strip, the locking ring is provided with a clamping groove, the clamping strip is clamped with the clamping groove, the locking ring is provided with a protrusion matching the locking hole, one end of the locking spring is fixedly connected to the locking ring, the other end of the locking spring is fixedly connected to the bushing, and both ends of the locking spring are connected to an electronic switch K 2  and a DC power supply BT 2  respectively by using wires. The driving spring contracts when a current is applied to the driving spring. An amount of contraction is related to the applied current. A size of the current applied to the driving spring is adjusted through PWM control of the electronic switch K 1 , so as to control the amount of contraction of the driving spring. Similarly, the locking ring and the locking hole are locked or separated through PWM control of the electronic switch K 2 . When the driving spring contracts, the friction rod is driven to move, so as to drive the friction wheel to rotate, in other words, drive the driving gear to rotate. When the electronic switch K 1  remains disconnected, the driving spring stretches, and the friction wheel rotates reversely. In this case, the electronic switch K 2  is also controlled to be disconnected, and the locking spring stretches to tightly lock the locking ring and the locking hole. In this way, the friction wheel cannot rotate reversely because it is locked, in other words, the driving gear rotates along one direction. The friction wheel only needs to be locked when the driving spring contracts and unlocked when the driving spring stretches, to make the driving gear rotate along another direction. 
     Preferably, the first wire hanging head and the second wire hanging head each are provided with a groove, an inner wall of the groove is provided with a notch, tail ends of the left hanging rod and the right hanging rod each are installed with a hanging mechanism, and the hanging mechanism is connected to the groove; and the hanging mechanism includes a hanging spring, a hanging joint, and a hanging ball, the tail ends of the left hanging rod and the right hanging rod each are provided with a blind hole, a wall of the blind hole is provided with a through hole along a radial direction, the hanging ball is placed in the through hole, the hanging joint is sleeved into an opening of the blind hole, one end of the hanging spring is fixedly connected to the bottom of the blind hole, the other end of the hanging spring is connected to the hanging joint, both ends of the hanging spring are connected to an electronic switch K 3  and a DC power supply BT 3  respectively by using wires, the hanging joint matches the grooves of the first wire hanging head and the second wire hanging head, the hanging joint is abutted with the hanging spring, an outer wall of the hanging joint is provided with a locking portion for extruding the hanging ball out of outer walls of the left hanging rod and the right hanging rod, and the outer wall of the hanging joint is further provided with an accommodation portion for retracting the hanging ball into the outer walls of the left hanging rod and the right hanging rod. When the hanging spring contracts, the hanging joint is pulled to rise, such that the accommodation portion is abutted with the hanging ball. The first wire hanging head and the second wire hanging head squeeze the hanging ball into the left hanging rod and the right hanging rod under the action of gravity, and the first wire hanging head and the second wire hanging head immediately fall to the ground. 
     Preferably, the robot further includes a stay wire head and a stayed pole, where the stayed pole is fixedly installed on the overturning frame, the stay wire head is rotatably connected to the stayed pole, and the overturning stay wire is fixedly connected to the stay wire head. 
     Preferably, the robot further includes a pressure spring, where the driving motor is connected to a square shaft, the overturning frame is provided with a walking wheel installation groove, the square shaft is rotatably connected to the walking wheel installation groove, the walking wheel is connected to the square shaft, and the pressure spring is installed between the walking wheel and the walking wheel installation groove. 
     The present disclosure has the following substantive effects: The hanging wire is lifted by the UAV, the lowest end of the hanging wire is raised to the position higher than the target conductor, and then the hanging wire is released after the UAV crosses the target conductor, such that the hanging wire is hanged on the target conductor. Ground staff raise the robot by pulling the hanging wire, and the operator can complete an operation on the ground, without a need to climb a tower or enter an electric field, improving operation safety. Most complex terrains can be covered without the help of large devices such as an insulated bucket arm truck, which achieves good applicability and portability, and improves operation efficiency. The UAV is used to carry a light hanging wire to help the robot walk onto a line, such that the robot can easily walk onto the line from an appropriate position and quickly walk to an installation position, reducing operation time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of installing a wire hanging bracket according to Embodiment  1 ; 
         FIG. 2  is a schematic diagram of wire hanging by a UAV according to Embodiment 1; 
         FIG. 3  is a schematic diagram of a result of wire hanging by a UAV according to Embodiment 1; 
         FIG. 4  is a schematic diagram of connecting a hanging wire to a robot according to Embodiment 1; 
         FIG. 5  is a schematic diagram of walking onto a line by a walking wheel of a robot according to Embodiment 1; 
         FIG. 6  is a schematic diagram of a clamp seat of a robot according to Embodiment 1; 
         FIG. 7  is a schematic structural diagram of a wire hanging bracket according to Embodiment 2; 
         FIG. 8  is a structural exploded view of a wire hanging bracket according to Embodiment 2; 
         FIG. 9  is a schematic diagram of a driving mechanism of a wire hanging bracket according to Embodiment 2; 
         FIG. 10  is a schematic cross-sectional diagram of a driving mechanism of a wire hanging bracket according to Embodiment 2; and 
         FIG. 11  is a schematic cross-sectional diagram of a hanging mechanism according to Embodiment 2. 
     
    
    
     In the figures:  101 : hanging tray;  102 : first wire hanging head;  103 : wire hanging bracket;  104 : second wire hanging head;  105 : UAV;  106 : left hanging rod;  107 : bushing;  108 : right hanging rod;  109 : left rack;  110 : right rack;  111 : driving pipe;  112 : friction rod;  113 : friction wheel;  114 : driving gear;  115 : driving spring;  116 : locking spring;  117 : fixed shaft;  118 : locking ring;  119 : locking hole;  120 : hanging spring;  121 : hanging joint;  122 : hanging ball;  123 : protrusion;  124 : groove;  125 : notch;  126 : blind hole;  127 : through hole;  128 : locking portion;  129 : accommodation portion;  201 : first hanging wire;  202 : second hanging wire;  203 : overturning stay wire;  3 : target conductor;  401 : overturning frame;  402 : walking wheel;  403 : driving motor;  404 : support;  405 : stayed pole;  406 : workbench;  407 : pressure spring;  408 : square shaft;  409 : stay wire head;  410 : clamp seat;  411 : tightening mechanism;  412 : wire hanging point;  413 : lockhole;  414 : electric lock;  415 : walking wheel installation groove;  5 : puncture clamp. 
     DETAILED DESCRIPTION 
     Specific implementations of the present disclosure are further specifically described below with reference to the accompanying drawings and specific embodiments. 
     Embodiment 1 
     A UAV-assisted hanging ring robot for live installation and grounding is used together with a UAV  105 , and includes a hanging tray  101 , a wire hanging bracket  103 , a hanging wire, an overturning stay wire  203 , an overturning frame  401 , a support  404 , an electric lock  414 , a walking wheel  402 , a driving motor  403 , a workbench  406 , a clamp seat  410 , a puncture clamp  5 , a tightening mechanism  411 , a remote controller, and a controller. As shown in  FIG. 1 , the hanging tray  101  is installed at a bottom of the UAV  105 , the wire hanging bracket  103  is fixedly connected to the hanging tray  101 , and the hanging wire is connected to the wire hanging bracket  103 . As shown in  FIG. 2  and  FIG. 3 , the hanging wire includes a first hanging wire  201  and a second hanging wire  202 , both ends of the wire hanging bracket  103  are respectively connected to a first wire hanging head  102  and a second wire hanging head  104 , the first hanging wire  201  is fixedly connected to the first wire hanging head  102 , the second hanging wire  202  is connected to the second wire hanging head  104 , the workbench  406  has two wire hanging points  412 , and a length of the wire hanging bracket  103  corresponds to a distance between the two wire hanging points  412  of the workbench  406 . The UAV  105  flies to above a target conductor  3 , such that the first hanging wire  201  and the second hanging wire  202  are located on both sides of the target conductor  3  respectively. Then, the UAV  105  rotates along itself, such that the first hanging wire  201  and the second hanging wire  202  cling to the target conductor  3 . The UAV  105  moves along a normal direction of the target conductor  3  to release one of the hanging wires, such as the first hanging wire  201 , and makes both ends of the first hanging wire  201  hang on ground after hanging the first hanging wire  201  on the target conductor  3 . After that, the UAV  105  moves reversely relative to the above movement along the normal direction to release the other hanging wire, such as the second hanging wire  202 , such that both ends of the second hanging wire  202  hang on the ground after the second hanging wire  202  is hanged on the target conductor  3 . In this way, the first hanging wire  201  and the second hanging wire  202  are hanged on the target conductor  3 . 
     As shown in  FIG. 4 ,  FIG. 5 , and  FIG. 6 , both the support  404  and the clamp seat are installed on the workbench  406 , the overturning frame  401  is rotatably installed on the support  404 , the electric lock is installed on the support  404 , the overturning frame  401  is provided with a lockhole  413  matching the electric lock, a stay wire head  409 , and a stayed pole  405 , the stayed pole  405  is fixedly installed on the overturning frame  401 , the stay wire head  409  is rotatably connected to the stayed pole  405 , and the overturning stay wire  203  is fixedly connected to the stay wire head  409 . The walking wheel  402  is rotatably installed on the overturning frame  401 , the driving motor  403  is installed on the overturning frame  401 , the driving motor  403  is connected to a square shaft  408 , the overturning frame  401  is provided with a walking wheel installation groove  415 , the square shaft  408  is rotatably connected to the walking wheel installation groove  415 , and the walking wheel  402  is connected to the square shaft  408 . A pressure spring  407  is installed between the walking wheel  402  and the walking wheel installation groove  415 , and the walking wheel  402  is connected to the driving motor  403 . The puncture clamp  5  is installed on the clamp seat, the tightening mechanism is installed on the workbench  406  and connected to a tightening screw of the puncture clamp. The electric lock, the tightening mechanism, the driving motor  403 , and the remote controller are connected to the controller. 
     This embodiment has the following beneficial effects: The hanging wire is lifted by the UAV  105 , a lowest end of the hanging wire is raised to a position higher than the target conductor  3 , and then the hanging wire is released after the UAV  105  crosses the target conductor  3 , such that the hanging wire is hanged on the target conductor  3 . Ground staff raise the robot by pulling the hanging wire, and an operator can complete an operation on the ground, without a need to climb a tower or enter an electric field, improving operation safety. Most complex terrains can be covered without the help of large devices such as an insulated bucket arm truck, which achieves good applicability and portability, and improves operation efficiency. The UAV  105  is used to carry a light hanging wire to help the robot walk onto a line, such that the robot can easily walk onto the line from an appropriate position and quickly walk to an installation position, reducing operation time. 
     Embodiment 2 
     Based on Embodiment 1, this embodiment makes a further improvement to the wire hanging bracket  103 . As shown in  FIG. 7  and  FIG. 8 , in this embodiment, the wire hanging bracket  103  includes a bushing  107 , a left hanging rod  106 , a right hanging rod  108 , a left rack  109 , a right rack  110 , a driving gear  114 , and a driving mechanism. The left hanging rod  106  and the right hanging rod  108  are sleeved on a left and a right of the bushing  107  respectively, the left rack  109  is fixedly connected to the left hanging rod  106 , the right rack  110  is fixedly connected to the right hanging rod  108 , the driving gear  114  is rotatably connected to the bushing  107 , the driving mechanism is connected to the driving gear  114 , both the left rack  109  and the right rack  110  are meshed with the driving gear  114 , the left hanging rod  106  is connected to the first wire hanging head  102 , and the right hanging rod  108  is connected to the second wire hanging head  104 . The driving mechanism drives the driving gear  114  to rotate, to drive the left rack  109  and the right rack  110  to move, such that extension elongations of the left hanging rod  106  and the right hanging rod  108  are changed to adjust the length of the wire hanging bracket  103  to adapt to different robots. 
     As shown in  FIG. 9  and  FIG. 10 , the driving mechanism includes a friction rod  112 , a friction wheel  113 , a fixed shaft  117 , a driving pipe  111 , a driving spring  115 , a locking spring  116 , and a locking ring  118 . The fixed shaft  117  is fixedly connected to the bushing  107 , the driving gear  114  is rotatably connected to the fixed shaft  117 , the friction wheel  113  is concentrically and fixedly connected to the driving gear  114 , the driving pipe  111  is fixedly connected to the bushing  107 , the driving spring  115  is installed in the driving pipe  111 , one end of the friction rod  112  is sleeved into the driving pipe  111 , one end of the driving spring  115  is fixedly connected to the driving pipe  111 , the other end of the driving spring  115  is fixedly connected to the friction rod  112 , both ends of the driving spring  115  are connected to an electronic switch K 1  and a DC power supply BT 1  respectively by using wires, the friction rod  112  is abutted with the friction wheel  113 , the friction wheel  113  is hollow and provided with an opening at one end away from the driving gear  114 , one end, close to the driving gear  114 , of the friction wheel  113  is provided with a locking hole  119 , the locking ring  118  is sleeved on the fixed shaft  117 , the fixed shaft  117  is provided with a clamping strip, the locking ring  118  is provided with a clamping groove, the clamping strip is clamped with the clamping groove, the locking ring  118  is provided with a protrusion  123  matching the locking hole  119 , one end of the locking spring  116  is fixedly connected to the locking ring  118 , the other end of the locking spring  116  is fixedly connected to the bushing  107 , and both ends of the locking spring  116  are connected to an electronic switch K 2  and a DC power supply BT 2  respectively by using wires. The driving spring  115  contracts when a current is applied to the driving spring  115 . An amount of contraction is related to the applied current. A size of the current applied to the driving spring  115  is adjusted through PWM control of the electronic switch K 1 , so as to control the amount of contraction of the driving spring  115 . Similarly, the locking ring  118  and the locking hole  119  are locked or separated through PWM control of the electronic switch K 2 . When the driving spring  115  contracts, the friction rod  112  is driven to move, so as to drive the friction wheel  113  to rotate, in other words, drive the driving gear  114  to rotate. When the electronic switch K 1  remains disconnected, the driving spring  115  stretches, and the friction wheel  113  rotates reversely. In this case, the electronic switch K 2  is also controlled to be disconnected, and the locking spring  116  stretches to tightly lock the locking ring  118  and the locking hole  119 . In this way, the friction wheel  113  cannot rotate reversely because it is locked, in other words, the driving gear  114  rotates along one direction. The friction wheel  113  only needs to be locked when the driving spring  115  contracts and unlocked when the driving spring  115  stretches, to make the driving gear  114  rotate along another direction. 
     Circuit structures of the above electronic switches K 1  and K 2 , and DC power supplies BT 1  and BT 2  are the same as those of the following electronic switch K 3  and DC power supply BT 3 . 
     As shown in  FIG. 11 , the first wire hanging head  102  and the second wire hanging head  104  each are provided with a groove  124 , an inner wall of the groove is provided with a notch  125 , tail ends of the left hanging rod  106  and the right hanging rod  108  each are installed with a hanging mechanism, the hanging mechanism is connected to the groove  124  and includes a hanging spring  120 , a hanging joint  121 , and a hanging ball  122 , the tail ends of the left hanging rod  106  and the right hanging rod  108  each are provided with a blind hole  126 , a wall of the blind hole  126  is provided with a through hole  127  along a radial direction, the hanging ball  122  is placed in the through hole  127 , the hanging joint  121  is sleeved into an opening of the blind hole  126 , one end of the hanging spring  120  is fixedly connected to the bottom of the blind hole, the other end of the hanging spring  120  is connected to the hanging joint  121 , both ends of the hanging spring  120  are connected to an electronic switch K 3  and a DC power supply BT 3  respectively by using wires, the hanging joint  121  matches the grooves  124  of the first wire hanging head  102  and the second wire hanging head  104 , the hanging joint  121  is abutted with the hanging spring  120 , an outer wall of the hanging joint  121  is provided with a locking portion  128  for extruding the hanging ball  122  out of outer walls of the left hanging rod  106  and the right hanging rod  108 , and the outer wall of the hanging joint  121  is further provided with an accommodation portion  129  for retracting the hanging ball  122  into the outer walls of the left hanging rod  106  and the right hanging rod  108 . When the hanging spring  120  contracts, the hanging joint  121  is pulled to rise, such that the accommodation portion  129  is abutted with the hanging ball  122 . The first wire hanging head  102  and the second wire hanging head  104  squeeze the hanging ball  122  into the left hanging rod  106  and the right hanging rod  108  under the action of gravity, and the first wire hanging head  102  and the second wire hanging head  104  immediately fall to the ground. 
     The above embodiments are merely preferred solutions of the present disclosure and is not intended to limit the present disclosure in any form, and other variations and modifications may be made without departing from the technical solution of the present disclosure as set forth in the appended claims.