A method and device for automatically tensioning a power cable

Abstract

The present invention relates to the technical field of power cable tensioning, and in particular to a method and device for automatically tensioning a power cable, which obtains the stability of the power cable, and screens out a target operating power reduction range of the tensioning mechanism in combination with a preset operating power reduction range of a clamping mechanism, a take-up speed of the tensioning mechanism at an initial moment and a second moment, and the stability at the initial moment and the second moment. Finally, based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, the tensioning mechanism and the clamping mechanism are controlled, so as to ensure that the take-up speed of the tensioning mechanism and the pressure applied to the power cable by the clamping mechanism are adapted during the reduction process, thereby avoiding the possibility of abnormal conditions in the power cable caused by inconsistency between the two, thereby avoiding damage to the power cable or low efficiency of taking up the power cable.

Description

Technical Field

[0001] The present invention relates to the technical field of power cable tensioning, and in particular to a method and a device for automatically tensioning a power cable. Background Art

[0002] Affected by gravity and weather factors, overhead power cables may fall. The essence of this is that the length of the power cables increases within a fixed range. Therefore, it is necessary to set a power cable tensioning mechanism at a section of the power cable to shorten the length of the power cable and make it taut. Figure 1 As shown, a tensioning mechanism 1 and a clamping mechanism 2 are provided, and the power cable 3 passes through the clamping mechanism 2 and extends to the power cable tensioning mechanism 1, and the tensioning mechanism 1 is fixed on the wire rod 4. In the process of the power cable tensioning mechanism 1 tensioning the power cable, the clamping mechanism 2 clamps and fixes the power cable. The clamping mechanism 2 is used to clamp the power cable 3 by clamping or the like, and apply a certain clamping force to the power cable 3, so that the power cable 3 is fixed under the action of the friction force generated between the clamping mechanism 2 and the power cable 3 to prevent left and right movement. Therefore, the operating power of the clamping mechanism 2 determines the size of the clamping force applied to the power cable 3, that is, the size of the friction force between the clamping mechanism 2 and the power cable 3. Therefore, with the cooperation of the tensioning mechanism 1 and the clamping mechanism 2, the power cable 3 is effectively tensioned.

[0003] Usually, the tensioning speed of the tensioning mechanism 1 on the power cable 3, that is, the winding speed, is fixed, and the clamping force applied to the power cable 3 by the clamping mechanism 2 is also fixed. When the tensioning mechanism 1 is tensioning the power cable 3, the state of the power cable 3 is constantly changing from being relaxed to being tight. During the state change of the power cable 3, if the tensioning speed of the tensioning mechanism 1 on the power cable 3 and the clamping force applied to the power cable 3 by the clamping mechanism 2 are fixed, the tensioning speed and the clamping force may not match. For example, if the tensioning speed of the tensioning mechanism 1 on the power cable 3 is too large, and the clamping force applied to the power cable 3 by the clamping mechanism 2 is too large, the two may not match, and the force resisting the stretching of the power cable 3 during the winding process will increase, thereby causing the possibility of the power cable 3 breaking. Therefore, the existing method may cause abnormal conditions in the power cable 3 due to the mismatch of the tensioning speed and the clamping force, thereby causing the power cable 3 to be damaged, or the winding efficiency of the power cable 3 is low. Summary of the invention

[0004] In view of this, in order to solve the above technical problems, the present invention provides a method and device for automatically tensioning a power cable.

[0005] The technical solutions adopted are as follows:

[0006] A method for automatically tensioning a power cable, wherein the power cable automatic tensioning device applicable to the method comprises a tensioning mechanism and a clamping mechanism, wherein the power cable extends into the tensioning mechanism through the clamping mechanism, and the clamping mechanism is used to apply a certain clamping force to the power cable, and the method comprises:

[0007] Acquiring a stability degree of the power cable, wherein the stability degree represents a shaking condition of the power cable;

[0008] At each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment are combined to obtain the target operating power reduction range from the preset operating power reduction range; the initial moment is the moment when the tensioning mechanism and the clamping mechanism are controlled to start operating, and the second moment is the next moment of the initial moment;

[0009] Based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, the tensioning mechanism and the clamping mechanism are controlled.

[0010] In one embodiment, obtaining the stability of the power cable includes:

[0011] Acquire a plurality of consecutive frames of power cable images;

[0012] Obtaining the distance between the preset positions in each two adjacent frame images, obtaining the distance features corresponding to each two adjacent frame images, and obtaining the average value of the distance features;

[0013] Obtaining the degree of stability based on an average value of the distance feature and distance features corresponding to the last two frames of the plurality of consecutive frames of power cable images;

[0014] The automatic tensioning method for power cables also includes: when the stability level is less than a preset stability threshold, controlling the tensioning mechanism and the clamping mechanism to start running, and the acquisition time corresponding to the last frame of the plurality of consecutive frames of power cable images is the initial time.

[0015] In one embodiment, at each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment are combined, and the target operating power reduction range is obtained by screening from the preset operating power reduction range, including:

[0016] According to the candidate preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism and the cable stability influence trend at the second moment, the cable speed reduction range at the third moment is obtained; the candidate preset operating power reduction range is any preset operating power reduction range in the preset operating power reduction range interval, and the third moment is the next moment after the second moment; the cable stability influence trend at the second moment is obtained from the stability degree at the initial moment and the second moment, and the take-up speed at the initial moment and the second moment;

[0017] Obtaining the take-up speed at the third moment according to the reduction amplitude of the cable speed at the third moment and the take-up speed at the second moment;

[0018] Based on the take-up speed at the third moment, obtaining the cable stability influence trend at the third moment corresponding to the candidate preset operating power reduction amplitude;

[0019] The minimum cable stability impact trend is obtained from the cable stability impact trend at the third moment corresponding to each preset operating power reduction amplitude in the preset operating power reduction amplitude range of the tensioning mechanism, and the preset operating power reduction amplitude corresponding to the minimum cable stability impact trend is the target operating power reduction amplitude.

[0020] In one embodiment, the calculation formula of the cable stability influence trend at the second moment is:

[0021]

[0022] is the influence trend of cable stability at the second moment, norm is the normalization function, is the stability at the initial moment, is the stability at the second moment, is the take-up speed at the initial moment, is the take-up speed at the second moment.

[0023] In one embodiment, the process of obtaining the cable speed reduction amplitude at the third moment includes:

[0024] The cable stability influence trend at the second moment is used as the weight, the candidate preset operating power reduction range and the preset operating power reduction range of the clamping mechanism are weighted summed and normalized, and the normalized result is the cable speed reduction range at the third moment.

[0025] In one embodiment, obtaining the take-up speed at the third moment according to the cable speed reduction amplitude at the third moment and the take-up speed at the second moment includes:

[0026] Based on the reduction range of the cable speed at the third moment and the take-up speed at the second moment, obtaining a reduction amount of the take-up speed;

[0027] The wire-reeling speed at the third moment is obtained based on the wire-reeling speed at the second moment and the wire-reeling speed reduction amount.

[0028] In one embodiment, based on the take-up speed at the third moment, obtaining the cable stability influence trend at the third moment corresponding to the candidate preset operating power reduction amplitude includes:

[0029] The following calculation formula is used to calculate the cable stability influence trend at the third moment:

[0030]

[0031] is the influence trend of cable stability at the third moment, norm is the normalization function, is the stability at the second moment, is the stability of the third moment, is the take-up speed at the second moment, is the take-up speed at the third moment;

[0032] The stability at the third moment is obtained by the stability at the initial moment and the stability at the second moment.

[0033] In one embodiment, based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, controlling the tensioning mechanism and the clamping mechanism includes:

[0034] Starting from the third moment, the operating power of the tensioning mechanism at each moment is determined according to the target operating power reduction range of the tensioning mechanism, and the operating power of the clamping mechanism at each moment is determined according to the preset operating power reduction range of the clamping mechanism;

[0035] Based on the obtained operating power of the tensioning mechanism at each moment and the operating power of the clamping mechanism at each moment, respectively generate a power output control instruction of the tensioning mechanism at each moment and a power output control instruction of the clamping mechanism at each moment;

[0036] According to the power output control instructions of the tensioning mechanism at each moment and the power output control instructions of the clamping mechanism at each moment, the actions of the tensioning mechanism and the clamping mechanism are controlled respectively.

[0037] In one embodiment, the power cable automatic tensioning method further comprises:

[0038] If the moment when the power of the clamping mechanism drops to 0 is not later than the moment when the take-up speed of the tensioning mechanism drops to 0, then when the power of the clamping mechanism drops to 0, the take-up speed of the tensioning mechanism is controlled to drop to 0, and then the power of the clamping mechanism is set to the initial operating power;

[0039] If the moment when the power of the clamping mechanism drops to 0 is later than the moment when the take-up speed of the tensioning mechanism drops to 0, when the take-up speed of the tensioning mechanism drops to 0, the power of the clamping mechanism is controlled to be set to the initial operating power.

[0040] An automatic tensioning device for a power cable, comprising a tensioning mechanism and a clamping mechanism, wherein a power cable extends into the tensioning mechanism through the clamping mechanism, wherein the clamping mechanism is used to apply a certain clamping force to the power cable, and further comprising a power cable stability acquisition module and a controller, wherein the controller is connected to the power cable stability acquisition module, the tensioning mechanism and the clamping mechanism by signal;

[0041] The power cable stability acquisition module is used to acquire the stability of the power cable, and the stability represents the shaking of the power cable;

[0042] The controller selects a target operating power reduction range from the preset operating power reduction range at each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, combining the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment; the initial moment is the moment when the tensioning mechanism and the clamping mechanism are controlled to start operating, and the second moment is the next moment of the initial moment;

[0043] Based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, the tensioning mechanism and the clamping mechanism are controlled.

[0044] The present invention has at least the following beneficial effects: the operating power of the tensioning mechanism, that is, the winding speed of the tensioning mechanism, and the operating power of the clamping mechanism, that is, the pressure applied to the power cable are gradually reduced, and based on the stability of the power cable in the initial stage, that is, based on the shaking of the power cable in the initial stage, and combined with the preset operating power reduction amplitude of the clamping mechanism, the winding speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment, the target operating power reduction amplitude of the tensioning mechanism that is adapted to the actual situation is obtained, and then combined with the preset operating power reduction amplitude of the clamping mechanism, the actions of the tensioning mechanism and the clamping mechanism are controlled respectively, so as to ensure that the winding speed of the tensioning mechanism and the pressure applied to the power cable by the clamping mechanism are adapted during the reduction process, thereby avoiding the possibility of abnormal conditions in the power cable caused by inconsistency between the two, thereby avoiding damage to the power cable or low winding efficiency of the power cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the layout of the existing power cable tensioning mechanism and clamping mechanism;

[0046] Figure 2 It is a structural schematic diagram of the tensioning mechanism;

[0047] Figure 3 is a structural schematic diagram of the clamping mechanism;

[0048] Figure 4 It is the control principle diagram of the automatic tensioning device of power cables;

[0049] Figure 5 It is a flow chart for obtaining the degree of stability;

[0050] Figure 6 It is the overall flow chart of the execution process in the controller;

[0051] Figure 7 is a flow chart for obtaining the target operating power reduction range;

[0052] In the figure, 1 is a tensioning mechanism, 2 is a clamping mechanism, 3 is a power cable, 4 is a wire rod, 5 is a tensioning motor, 6 is a winding wheel, 7 is a tensioning motor driver, 8 is a speed sensor, 9 is a clamping arm, 10 is a driving assembly, 11 is a driving connecting rod, 12 is an insulating friction layer, 13 is a clamping motor, 14 is a power cable stability acquisition module, and 15 is a controller. DETAILED DESCRIPTION

[0053] An embodiment of an automatic tensioning device for power cables:

[0054] This embodiment provides an automatic tensioning device for power cables, including a tensioning mechanism 1 and a clamping mechanism 2, wherein a power cable 3 extends into the tensioning mechanism 1 through the clamping mechanism 1. As a specific implementation, the tensioning mechanism 1 is fixed on the wire rod 4, and the clamping mechanism 2 can also be fixed by a special fixing mechanism, and the spacing distance between the tensioning mechanism 1 and the clamping mechanism 2 is set according to actual needs.

[0055] The tensioning mechanism 1 may be a conventional electric-controlled wire-receiving device, which realizes the retraction and extension of the power cable 3 under the control of an electric signal. Figure 2 As shown, the tensioning mechanism 1 includes a tensioning motor 5 and a winding wheel 6. The specific motor type of the tensioning motor is set according to actual needs, such as a synchronous motor, an asynchronous motor, etc. The driving shaft of the tensioning motor 5 is connected to the winding wheel 6 in a transmission manner. The power cable 3 is used to be wound on the winding wheel 6 to retract and release the power cable 3, thereby achieving the tensioning of the power cable 3. As a specific embodiment, the winding wheel 6 is provided with a thread to increase the friction force to facilitate the winding of the power cable 3. Moreover, the rotating shaft of the winding wheel 6 is also provided with a speed sensor 8 for detecting the speed of the winding wheel 6, that is, the winding speed. Of course, the speed sensor 8 can also be set on the driving shaft of the tensioning motor 5. The tensioning motor 5 is electrically connected to the tensioning motor driver 7, and the tensioning motor driver 7 is used to drive the tensioning motor 5.

[0056] The clamping mechanism 2 is used to apply a certain clamping force to the power cable 3. The clamping mechanism 2 can be a conventional clamping mechanism, such as Figure 3 As shown, a specific structure of a clamping mechanism 2 is given, including a clamping motor 13, a plurality of clamping arms 9, and a driving assembly 10 corresponding to each clamping arm 9. Each clamping arm 9 is used to clamp the power cable 3. The positional relationship between the clamping arm 9 and the power cable 3 is set according to actual needs. In this embodiment, three clamping arms 9 are set, and the clamping direction is perpendicular to the axis of the power cable 3. The three clamping arms 9 are set in the same clamping plane. The clamping direction between each two clamping arms 9 is 120° to achieve the balance of applied force. Each driving assembly 10 is connected to the corresponding clamping arm 9 through a driving connecting rod 11, which is used to drive the corresponding clamping arms 9 to move. In order to improve the reliability and safety of the clamping of the power cable 3, an insulating friction layer 12 is provided between each clamping arm 9 and the power cable 3, which not only improves the friction force, but also improves the insulation effect. The insulating friction layer 12 can be made of insulating rubber. The clamping motor 13 is connected to each driving assembly 10, and the clamping motor 13 drives each driving assembly 10 to move, thereby driving each clamping arm 9 to move, and clamping the power cable 3.

[0057] As other embodiments, the clamping arms 9 can also be set to other numbers, such as 4, and the clamping direction between two adjacent clamping arms 9 is 90°, and other settings are consistent with the above. Moreover, the clamping mechanism 2 can also be set to other existing mechanisms, such as: a cable clamping device disclosed in the utility model patent with authorization announcement number CN212435256U, in which a motor drives bolt 2 to rotate to achieve cable clamping; or a cable routing trough cover clamping device disclosed in the utility model patent with authorization announcement number CN205791328U, which drives the positioning screw to rotate by a motor to achieve cable clamping; or a clamping mechanism disclosed in the invention patent with authorization announcement number CN110497232B.

[0058] The automatic tensioning device for power cables also includes a power cable stability acquisition module 14 and a controller 15. The controller 15 is connected to the power cable stability acquisition module 14, the tensioning mechanism 1 and the clamping mechanism 2 by signal. Specifically, the controller 15 is connected to the power cable stability acquisition module 14, the tensioning motor 5, the speed sensor 8 and the clamping motor 13 by signal. Figure 4 As shown. The controller 15 can be a control device such as a PLC, a single-chip microcomputer, a CPU, etc., and the specific selection is set according to actual needs. It should be understood that the above-mentioned signal connection can be a wired connection, or a short-distance wireless communication method such as a Bluetooth, WiFi module, etc. can be used for short-distance wireless communication connection, and a long-distance wireless communication method such as a GPRS module can be used for long-distance wireless communication connection.

[0059] The power cable stability acquisition module 14 is used to obtain the stability of the power cable 3. The stability represents the shaking of the power cable. The shaking occurs because when the power cable 3 is relatively loose, it will shake under the influence of the external environment, such as wind. The shaking degree, that is, the stability is affected by the degree of relaxation, wind speed, etc.

[0060] As a specific implementation, the power cable stability acquisition module 14 includes an image acquisition device, which can be a conventional camera. In order to acquire a reliable image of the power cable, the image acquisition device can be set above the power cable 3, and the image acquisition direction is set toward the power cable 3. The specific setting position of the image acquisition device is controlled by being able to reliably acquire an image of the power cable 3, that is, on the basis of ensuring that a reliable image of the power cable 3 can be acquired, the specific installation position of the image acquisition device and the height difference between the image acquisition device and the power cable 3 are set according to actual needs.

[0061] The image acquisition device acquires video images of the power cable 3 and obtains a number of continuous frames of power cable images therefrom. The number of image frames is set according to actual needs, and the time interval between adjacent image frames is determined by the video frame rate.

[0062] Since the degree of shaking is reflected in the distance between a certain position of the power cable 3 in different frames, the greater the distance, the higher the degree of shaking. Therefore, a detection position is preset on the power cable 3, and the detection position is set according to actual needs, such as being set at a position where the power cable is prone to shaking. As a specific example, in order to facilitate detection, the detection position can be specially marked, or an easily identifiable small object can be installed. The detection position in each frame of the power cable image is identified.

[0063] Then, if Figure 5 As shown, the distance between the detection positions in each two adjacent frame images is obtained as the distance feature corresponding to each two adjacent frame images. It should be understood that if the detection position is an image area, the center point of the image area is used as the detection position. According to the distance feature corresponding to each two adjacent frame images, the average value of the distance feature is calculated.

[0064] Based on the average value of the distance feature obtained and the distance feature corresponding to the last two frames of the power cable image in a number of consecutive frames, the stability is obtained. It should be understood that the average value of the distance feature reflects the overall shaking of the power cable 3 reflected in a number of consecutive frames of the power cable image. The larger the average value of the distance feature, the more serious the overall shaking, and the correspondingly lower the stability; the distance feature corresponding to the last two frames of the power cable image in a number of consecutive frames reflects the shaking of the power cable 3 reflected in the last two frames. The larger the distance feature, the more serious the shaking, and the correspondingly lower the stability. Therefore, the average value of the distance feature and the distance feature corresponding to the last two frames are negatively correlated with the stability.

[0065] As a specific implementation, the negative correlation normalized value of the average value of the distance feature and the negative correlation normalized value of the distance feature corresponding to the last two frames of images are obtained, and the two negative correlation normalized values ​​are multiplied to obtain the stability corresponding to several consecutive frames of power cable images. Among them, the negative correlation normalization can be calculated as follows: , x is the input quantity, and e is a natural constant.

[0066] Therefore, each time a number of consecutive frames of power cable images are acquired, a stability level will be obtained. According to prior knowledge, when the power cable 3 is in the process of winding, the power cable 3 is gradually tightened, and the shaking caused by external factors is finally smaller, that is, the stability level gradually increases. A stability threshold is preset, and the threshold is set according to actual needs. If the stability level is greater than or equal to the preset stability threshold, it means that the stability level of the power cable 3 is higher and the shaking level is lower; if the stability level is less than the preset stability threshold, it means that the stability level of the power cable 3 is lower and the shaking level is higher.

[0067] Figure 6 It is a data processing process executed in the controller 15. The controller 15 obtains the stability obtained each time, and compares the stability obtained each time with the preset stability threshold. When the stability is less than the preset stability threshold, it is necessary to perform a winding operation. Therefore, the controller 15 controls the tensioning mechanism 1 and the clamping mechanism 2 to start running, and takes the acquisition time corresponding to the last frame of the several consecutive frames of power cable images corresponding to the stability less than the preset stability threshold as the initial time. Therefore, the initial time is the time to control the tensioning mechanism 1 and the clamping mechanism 2 to start running. The above-mentioned stability obtained is the stability corresponding to the initial time. When the tensioning mechanism 1 and the clamping mechanism 2 start running, the operating power of the tensioning mechanism 1 is the preset initial operating power of the tensioning mechanism 1, and the operating power of the clamping mechanism 2 is the preset initial operating power of the clamping mechanism 2.

[0068] Starting from the initial moment, the subsequent moments are defined as: the second moment, the third moment, the fourth moment, the fifth moment, etc. The second moment is the next moment of the initial moment, the third moment is the next moment of the second moment, the fourth moment is the next moment of the third moment, the fifth moment is the next moment of the fourth moment, etc. Starting from the initial moment and the subsequent moments, the time interval between adjacent moments is set according to actual needs, such as 1 second.

[0069] Since the stability level at the second moment needs to be obtained later, similarly to the initial moment, several consecutive frames of power cable images are obtained with the second moment as the acquisition moment corresponding to the last frame image, and then the above process is used to obtain the corresponding stability level, which is the stability level corresponding to the second moment.

[0070] At the initial moment, an initial operating power is given to the tensioning mechanism 1, and an initial operating power is given to the clamping mechanism 2. At the initial moment, the tensioning mechanism 1 operates according to its corresponding initial operating power, and the clamping mechanism 2 operates according to its corresponding initial operating power. It should be understood that for the tensioning mechanism 1, the tensioning mechanism 1 is used for winding, and what it gives to the power cable 3 is the winding speed. Therefore, the higher the operating power of the tensioning mechanism 1, the faster the winding speed applied to the power cable 3, and the operating power is positively correlated with the winding speed applied to the power cable 3. When the operating power of the tensioning mechanism 1 is adjusted, the adjustment of the winding speed of the power cable 3 is achieved. Therefore, the winding speed of the power cable 3 is characterized by the operating power of the tensioning mechanism 1. The operating power of the clamping mechanism 2 is positively correlated with the clamping force applied to the power cable 3. The greater the operating power, the greater the clamping force, and the greater the friction force applied to the power cable 3. Therefore, by adjusting the operating power of the clamping mechanism 2, the adjustment of the friction force applied to the power cable 3 is achieved, and the friction force applied to the power cable 3 is characterized by the operating power of the clamping mechanism 2.

[0071] As other implementations, the stability can also be obtained in other forms, such as setting a shaking sensor at at least one position of the power cable 3, specifically a three-axis acceleration sensor, to obtain the shaking degree of the power cable 3, and the stability can be obtained by negatively correlating the shaking degree, and transmitted to the controller 15. It should be understood that in order to facilitate data transmission, the three-axis acceleration sensor can be powered by a high-capacity battery and connected to the controller 15 by wireless communication without the need for special wiring.

[0072] In this embodiment, the operating power reduction range of the clamping mechanism 2 is preset, and starting from the second moment, the clamping mechanism 2 always controls the operating power of the clamping mechanism 2 to reduce according to the preset operating power reduction range. The preset operating power reduction range of the clamping mechanism 2 is set according to actual needs, for example: 1 / 20, that is, starting from the second moment, the operating power reduction range of the clamping mechanism 2 each time is 1 / 20 of the operating power at the previous moment, that is:

[0073]

[0074] in, is the operating power of the clamping mechanism 2 at the i-th moment in each subsequent moment starting from the second moment, X is the preset operating power reduction amplitude of the clamping mechanism 2, is the operating power of the clamping mechanism 2 at the i-1th moment.

[0075] It should be understood that under the above calculation method, the operating power of the clamping mechanism 2 will never be 0. In order to prevent this situation, when the operating power of the clamping mechanism 2 is too low, such as when it is reduced to a preset lower limit value, the operating power of the clamping mechanism 2 is directly set to 0.

[0076] In this embodiment, the tensioning mechanism 1 is preset with an operating power reduction range, and the preset operating power reduction range is a numerical range, which is the allowable operating power reduction range of the tensioning mechanism 1. It should be understood that the range length and upper and lower limits of the preset operating power reduction range are set by actual conditions. The focus of this embodiment is to obtain a relatively accurate operating power reduction range that matches the operating power reduction range of the clamping mechanism 2 from the preset operating power reduction range, so that the reduction range of the take-up speed of the tensioning mechanism 1 is compatible with the friction force applied by the clamping mechanism 2 to the power cable 3. As a specific example, the preset operating power reduction range can be [1 / 80, 1 / 10], where a value is taken every 1 / 400, then the range is [5 / 400, 6 / 400, 7 / 400, 8 / 400, ..., 40 / 400].

[0077] The initial operating power of the tensioning mechanism 1 at the initial moment is first reduced according to the preset operating power reduction range of the clamping mechanism 2, so as to obtain the operating power of the tensioning mechanism 1 at the second moment. The calculation method of the operating power of the tensioning mechanism 1 at the second moment is the same as the calculation formula of the operating power reduction of the clamping mechanism 2, and the calculation formula is:

[0078]

[0079] in, is the operating power of the tensioning mechanism 1 at the second moment, is the initial operating power of the tensioning mechanism 1. Since the target operating power reduction range of the tensioning mechanism 1 has not yet been determined, and in order to adapt the operating power reduction ranges of the tensioning mechanism 1 and the clamping mechanism 2, the operating power of the tensioning mechanism 1 at the second moment is first obtained according to the preset operating power reduction range of the clamping mechanism 2.

[0080] The wire-winding speed of the tensioning mechanism 1 at the second moment is acquired by the rotation speed sensor 8 .

[0081] It should be understood that the initial moment is a historical moment, and the corresponding state is a historical state; the second moment is the current moment, and the corresponding state is the current state; starting from the third moment, each subsequent moment is a future moment, and the corresponding state is a future state.

[0082] The controller 15 obtains the target operating power reduction range from the preset operating power reduction range at each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism 1, by combining the preset operating power reduction range of the clamping mechanism 2, the winding speed of the tensioning mechanism 1 at the initial moment and the second moment, and the degree of stability at the initial moment and the second moment.

[0083] As a specific implementation, Figure 7 As shown, the screening of the target operating power reduction range includes the following implementation process:

[0084] As follows, data processing is performed using any one of the preset operating power reduction ranges in the preset operating power reduction range as the data processing object, and a candidate preset operating power reduction range is set to be any one of the preset operating power reduction ranges in the preset operating power reduction range, and finally the cable stability impact trend at the third moment corresponding to the candidate preset operating power reduction range is obtained, and finally a final judgment is made based on the cable stability impact trend at the third moment corresponding to each preset operating power reduction range in the preset operating power reduction range.

[0085] The influence trend of the cable stability at the second moment is obtained, and the influence trend of the cable stability at the second moment is obtained by the stability at the initial moment and the second moment, and the take-up speed at the initial moment and the second moment. The take-up speed at the initial moment and the second moment is detected by the rotation speed sensor 8 at the corresponding moment.

[0086] As a specific implementation, the calculation formula for the cable stability influence trend at the second moment is:

[0087]

[0088] is the influence trend of cable stability at the second moment, norm is the normalization function, is the stability at the initial moment, is the stability at the second moment, is the take-up speed at the initial moment, is the take-up speed at the second moment.

[0089] The faster the take-up speed is, the greater the impact on the stability of the power cable 3 is, making its stability lower. Therefore, the stability is weighted by using the fraction of the take-up speed, thus obtaining: and , and then obtain the change in the stability corresponding to two adjacent sampling moments, thus obtaining , the larger the value, the greater the influence of the winding speed change at the second moment on the stability of the power cable 3, which also indicates that the winding speed at the second moment is not appropriate, and the necessity of reducing the winding speed is higher. Finally, the norm function is used for normalization. It should be understood that the normalization in this embodiment can select one of the existing normalization methods according to actual needs, such as: maximum and minimum value normalization method, or use Normalization is performed in the following way, where x is the data to be normalized.

[0090] According to the candidate preset operating power reduction range of the tensioning mechanism 1, the preset operating power reduction range of the clamping mechanism 2, and the cable stability influence trend at the second moment, the cable speed reduction range at the third moment is obtained. The process of obtaining the cable speed reduction range at the third moment includes: converting the cable stability influence trend at the second moment As a weight, the candidate preset operating power reduction range and the preset operating power reduction range of the clamping mechanism 2 are weighted summed and normalized, and the normalized result is the cable speed reduction range at the third moment. As a specific implementation, the calculation formula of the cable speed reduction range at the third moment is given as follows:

[0091]

[0092] is the candidate preset operating power reduction range, It is the preset operating power reduction range of the clamping mechanism 2.

[0093] According to the reduction range of the cable speed at the third moment and the take-up speed at the second moment, the take-up speed at the third moment is obtained, specifically as follows: Based on the reduction range of the cable speed at the third moment and the take-up speed at the second moment, the take-up speed reduction amount is obtained; based on the take-up speed at the second moment and the take-up speed reduction amount, the take-up speed at the third moment is obtained. , the calculation formula is as follows:

[0094]

[0095] Based on the take-up speed at the third moment, the cable stability influence trend at the third moment corresponding to the candidate preset operating power reduction range is obtained. Similar to the process of obtaining the cable stability influence trend at the second moment, the following calculation formula is used to calculate the cable stability influence trend at the third moment: :

[0096]

[0097] in, is the stability of the third moment, is the take-up speed at the third moment.

[0098] Since all moments from the third moment onwards are future moments, the stability of the third moment cannot be directly calculated. Therefore, in this embodiment, the stability of the third moment The stability at the initial moment and the stability of the second moment It can be obtained and predicted. The prediction algorithm can be an existing prediction method, for example: taking the stability as the vertical axis and each moment as the horizontal axis, constructing a coordinate system and dividing the stability And stability The corresponding coordinate points are mapped to the coordinate system, and a straight line is fitted based on the two coordinate points. Then, based on the abscissa being the third moment, the ordinate of the third moment on the fitted straight line is obtained, and the obtained ordinate is the degree of stability at the third moment. Moreover, since the stability cannot be reduced, if the stability at the third moment is Below stability , then the stability of the third moment Set to stability As another implementation method, the stability level can also be directly As the third moment of stability , or the stability and the stability of the second moment The average value of Similarly, if the stability of the third moment is Below stability , then the stability of the third moment Set to stability .

[0099] By adopting the above process, the cable stability influence trend at the third moment corresponding to each preset operating power reduction amplitude in the preset operating power reduction amplitude interval of the tensioning mechanism 1 can be obtained. Since the cable stability influence trend represents the influence of the take-up speed on the stability of the power cable 3, it is necessary to reduce this influence as much as possible. The smaller the cable stability influence trend, the higher the stability. Therefore, the minimum cable stability influence trend is obtained from the cable stability influence trend at the third moment corresponding to each preset operating power reduction amplitude in the preset operating power reduction amplitude interval, and the preset operating power reduction amplitude corresponding to the minimum cable stability influence trend is the target operating power reduction amplitude at the second moment.

[0100] Therefore, through the above process, the target operating power reduction range of the tensioning mechanism 1 can be obtained.

[0101] Finally, based on the target operating power reduction range of the tensioning mechanism 1 and the preset operating power reduction range of the clamping mechanism 2, the tensioning mechanism 1 and the clamping mechanism 2 are controlled. Specifically, starting from the third moment, according to the target operating power reduction range of the tensioning mechanism 1, the operating power of the tensioning mechanism 1 at each moment is determined. The acquisition process is the same as the calculation formula for the operating power reduction of the clamping mechanism 2 above. The calculation formula is as follows:

[0102]

[0103] in, is the operating power of the tensioning mechanism 1 at the i-th moment in the subsequent moments starting from the third moment, Y is the target operating power reduction amplitude of the tensioning mechanism 1, is the operating power of the tensioning mechanism 1 at the i-1th moment.

[0104] At the same time, according to the preset operating power reduction range of the clamping mechanism 2, the operating power of the clamping mechanism 2 at each moment is determined, and the calculation formula is as mentioned above.

[0105] Then, based on the obtained operating power of the tensioning mechanism 1 at each moment, the power output control instructions of the tensioning mechanism 1 at each moment are generated; based on the operating power of the clamping mechanism 2 at each moment, the power output control instructions of the clamping mechanism 2 at each moment are generated. Finally, according to the power output control instructions of the tensioning mechanism 1 at each moment, the action of the tensioning mechanism 1 is controlled, and according to the power output control instructions of the clamping mechanism 2 at each moment, the action of the clamping mechanism 2 is controlled.

[0106] Through the above process, the take-up speed of the tensioning mechanism 1 can be made lower and lower, and the friction force applied to the power cable 3 by the clamping mechanism 2 can be made lower and lower. When the operating power of the tensioning mechanism 1 drops to 0, the take-up speed of the tensioning mechanism 1 drops to 0; when the operating power of the clamping mechanism 2 drops to 0, the friction force applied to the power cable 3 by the clamping mechanism 2 is 0.

[0107] In this embodiment, the controller 15 is also used for: if the moment when the power of the clamping mechanism 2 drops to 0 is not later than the moment when the take-up speed of the tensioning mechanism 1 drops to 0, that is, the moment when the friction force applied by the clamping mechanism 2 to the power cable 3 drops to 0 is earlier than or arrives at the same time as the moment when the take-up speed of the tensioning mechanism 1 drops to 0, then when the power of the clamping mechanism 2 drops to 0, the take-up speed of the tensioning mechanism 1 is controlled to drop to 0, and the take-up is stopped, and in order to prevent the power cable 3 from moving in the opposite direction, the power of the clamping mechanism 2 is set to the initial operating power, giving the power cable 3 a certain friction force.

[0108] If the moment when the power of the clamping mechanism 2 drops to 0 is later than the moment when the take-up speed of the tensioning mechanism 1 drops to 0, that is, the friction force applied by the clamping mechanism 2 to the power cable 3 drops to 0 later than the take-up speed of the tensioning mechanism 1 drops to 0, then when the take-up speed of the tensioning mechanism 1 drops to 0, the power of the clamping mechanism 2 is controlled to be set to the initial operating power to prevent the power cable 3 from moving in the reverse direction.

[0109] An embodiment of a method for automatically tensioning a power cable:

[0110] This embodiment provides an automatic tensioning method for power cables. The automatic tensioning method for power cables is applicable to an automatic tensioning device for power cables, which includes a tensioning mechanism and a clamping mechanism. The power cable extends into the tensioning mechanism through the clamping mechanism. The clamping mechanism is used to apply a certain clamping force to the power cable.

[0111] The automatic tensioning method for power cables comprises:

[0112] Acquiring a stability degree of the power cable, wherein the stability degree represents a shaking condition of the power cable;

[0113] At each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment are combined to obtain the target operating power reduction range from the preset operating power reduction range; the initial moment is the moment when the tensioning mechanism and the clamping mechanism are controlled to start operating, and the second moment is the next moment of the initial moment;

[0114] Based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, the tensioning mechanism and the clamping mechanism are controlled.

[0115] Since the structure of the automatic tensioning device for electric cables and the implementation process of the automatic tensioning method for electric cables have been specifically described in an embodiment of the automatic tensioning device for electric cables, they will not be described in detail in this embodiment.

[0116] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for automatically tensioning a power cable, wherein the method is applicable to an automatic tensioning device for a power cable, comprising a tensioning mechanism and a clamping mechanism, wherein the power cable extends into the tensioning mechanism through the clamping mechanism, and the clamping mechanism is used to apply a certain clamping force to the power cable, wherein: The automatic tensioning method for power cables comprises: Acquiring a stability degree of the power cable, wherein the stability degree represents a shaking condition of the power cable; At each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment are combined to obtain the target operating power reduction range from the preset operating power reduction range; the initial moment is the moment when the tensioning mechanism and the clamping mechanism are controlled to start operating, and the second moment is the next moment of the initial moment; Controlling the tensioning mechanism and the clamping mechanism based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism; Obtaining the stability of the power cable, including: Acquire a plurality of consecutive frames of power cable images; Obtaining the distance between the preset positions in each two adjacent frame images, obtaining the distance features corresponding to each two adjacent frame images, and obtaining the average value of the distance features; Obtaining the degree of stability based on an average value of the distance feature and distance features corresponding to the last two frames of the plurality of consecutive frames of power cable images; The automatic tensioning method for power cables further comprises: when the stability level is less than a preset stability threshold, controlling the tensioning mechanism and the clamping mechanism to start running, and the acquisition time corresponding to the last frame of the plurality of consecutive frames of power cable images is the initial time; At each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment are combined, and a target operating power reduction range is obtained by screening from the preset operating power reduction range, including: According to the candidate preset operating power reduction range of the tensioning mechanism, the preset operating power reduction range of the clamping mechanism and the cable stability influence trend at the second moment, the cable speed reduction range at the third moment is obtained; the candidate preset operating power reduction range is any preset operating power reduction range in the preset operating power reduction range interval, and the third moment is the next moment after the second moment; the cable stability influence trend at the second moment is obtained from the stability degree at the initial moment and the second moment, and the take-up speed at the initial moment and the second moment; Obtaining the take-up speed at the third moment according to the reduction amplitude of the cable speed at the third moment and the take-up speed at the second moment; Based on the take-up speed at the third moment, obtaining the cable stability influence trend at the third moment corresponding to the candidate preset operating power reduction amplitude; Obtaining a minimum cable stability influence trend from the cable stability influence trends at the third moment corresponding to each preset operating power reduction amplitude in the preset operating power reduction amplitude interval of the tensioning mechanism, the preset operating power reduction amplitude corresponding to the minimum cable stability influence trend being the target operating power reduction amplitude; The calculation formula for the cable stability influence trend at the second moment is: is the influence trend of cable stability at the second moment, norm is the normalization function, is the stability at the initial moment, is the stability at the second moment, is the take-up speed at the initial moment, is the take-up speed at the second moment.

2. The automatic tensioning method for power cables according to claim 1, characterized in that: The process of obtaining the cable speed reduction amplitude at the third moment includes: The cable stability influence trend at the second moment is used as the weight, the candidate preset operating power reduction range and the preset operating power reduction range of the clamping mechanism are weighted summed and normalized, and the normalized result is the cable speed reduction range at the third moment.

3. The automatic tensioning method for power cables according to claim 1, characterized in that: The wire take-up speed at the third moment is obtained according to the reduction range of the wire speed at the third moment and the wire take-up speed at the second moment, including: Based on the reduction range of the cable speed at the third moment and the take-up speed at the second moment, obtaining a reduction amount of the take-up speed; The wire-reeling speed at the third moment is obtained based on the wire-reeling speed at the second moment and the wire-reeling speed reduction amount.

4. The automatic tensioning method for power cables according to claim 1, characterized in that: Based on the take-up speed at the third moment, obtaining the cable stability influence trend at the third moment corresponding to the candidate preset operating power reduction amplitude, including: The following calculation formula is used to calculate the cable stability influence trend at the third moment: is the influence trend of cable stability at the third moment, norm is the normalization function, is the stability at the second moment, is the stability of the third moment, is the take-up speed at the second moment, is the take-up speed at the third moment; The stability at the third moment is obtained by the stability at the initial moment and the stability at the second moment.

5. The automatic tensioning method for power cables according to claim 1, characterized in that: Based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, the tensioning mechanism and the clamping mechanism are controlled, including: Starting from the third moment, the operating power of the tensioning mechanism at each moment is determined according to the target operating power reduction range of the tensioning mechanism, and the operating power of the clamping mechanism at each moment is determined according to the preset operating power reduction range of the clamping mechanism; Based on the obtained operating power of the tensioning mechanism at each moment and the operating power of the clamping mechanism at each moment, respectively generate a power output control instruction of the tensioning mechanism at each moment and a power output control instruction of the clamping mechanism at each moment; According to the power output control instructions of the tensioning mechanism at each moment and the power output control instructions of the clamping mechanism at each moment, the actions of the tensioning mechanism and the clamping mechanism are controlled respectively.

6. The automatic tensioning method for power cables according to claim 1, characterized in that: The automatic tensioning method for power cables also includes: If the moment when the power of the clamping mechanism drops to 0 is not later than the moment when the take-up speed of the tensioning mechanism drops to 0, then when the power of the clamping mechanism drops to 0, the take-up speed of the tensioning mechanism is controlled to drop to 0, and then the power of the clamping mechanism is set to the initial operating power; If the moment when the power of the clamping mechanism drops to 0 is later than the moment when the take-up speed of the tensioning mechanism drops to 0, when the take-up speed of the tensioning mechanism drops to 0, the power of the clamping mechanism is controlled to be set to the initial operating power.

7. An automatic power cable tensioning device according to an automatic power cable tensioning method according to claim 1, comprising a tensioning mechanism and a clamping mechanism, the power cable extends into the tensioning mechanism through the clamping mechanism, the clamping mechanism is used to apply a certain clamping force to the power cable, characterized in that: It also includes a power cable stability acquisition module and a controller, wherein the controller is signal-connected to the power cable stability acquisition module, the tensioning mechanism, and the clamping mechanism; The power cable stability acquisition module is used to acquire the stability of the power cable, and the stability represents the shaking of the power cable; The controller selects a target operating power reduction range from the preset operating power reduction range at each preset operating power reduction range in the preset operating power reduction range of the tensioning mechanism, combining the preset operating power reduction range of the clamping mechanism, the take-up speed of the tensioning mechanism at the initial moment and the second moment, and the stability at the initial moment and the second moment; the initial moment is the moment when the tensioning mechanism and the clamping mechanism are controlled to start operating, and the second moment is the next moment of the initial moment; Based on the target operating power reduction range of the tensioning mechanism and the preset operating power reduction range of the clamping mechanism, the tensioning mechanism and the clamping mechanism are controlled.

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