Safety collision avoidance risk assessment method for crane jib and electrified equipment

Abstract

The invention relates to a safety collision avoidance risk assessment method for a crane jib and electrified equipment, and belongs to the technical field of power construction. The method comprises the following steps: measuring electric field intensity by using an electric field sensor, and measuring and calculating a distance L1 from high-voltage live equipment to a test point; measuring and calculating the radial length L2 of the crane jib by using a pulse laser flight time measurement method; comparing the distance L1 from the electrified high-voltage equipment to the test point with the safety distance Ls1, and calculating a risk coefficient K1; comparing the radial length L2 of the crane jib with a safety threshold value Ls2, and calculating a risk coefficient K2; calculating a comprehensive risk coefficient Kave; and then the risk level is judged, and corresponding early warning is carried out. According to the invention, the problems of complex installation, high cost, poor compatibility and the like of a traditional anti-collision system are solved, the safety distance between the suspension arm and the electrified equipment in the hoisting operation can be evaluated in real time, the occurrence of collision accidents is effectively avoided, and the operation safety of an electric power construction site is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric power construction, and particularly relates to a crane jib and live equipment safe collision avoidance risk assessment method. BACKGROUND

[0002] In the electric power construction site, the lifting operation of cranes and other heavy machinery is a key link of safety management, and has a major impact on safety production and economic benefits. Due to the complex construction environment, the lifting equipment is of various types and large in size, and there are blind spots and errors in manual observation, which easily leads to collision accidents of insufficient safety distance between the jib and high-voltage lines or live equipment, causing power outages and secondary disasters, and affecting social stability.

[0003] In the heavy machinery operating environment, especially in the construction scene close to high-voltage live equipment, it is crucial to ensure a safe distance between the machinery and live equipment to ensure the safety of the operation. Such risk assessment needs to consider multiple factors such as physical distance, voltage level, and operating environment, and requires real-time monitoring of the site conditions and accurate calculation of the safety limit to build a scientific and comprehensive risk assessment system. Currently, the industry generally uses induced electric field strength or installs sensors to obtain the position state of the equipment to warn of potential collisions between heavy machinery and high-voltage lines. Although this method is simple in principle and easy to operate, its accuracy is affected by various factors such as weather conditions and surrounding electromagnetic interference, resulting in large deviations in measurement results and making it difficult to meet the high-reliability operation requirements. X-band radar technology has high precision and strong recognition, and can effectively monitor the distance between machinery and live equipment, but its complex design, high cost, and sensitivity to environmental conditions limit its widespread application. In summary, the existing anti-collision systems have some shortcomings such as complex installation process, high cost, and poor compatibility, making it difficult to be widely applied to various types of crane operations. In addition, the adaptability and data accuracy of existing technologies in complex environments still need to be improved.

[0004] In view of the fact that most anti-collision systems on the current market focus on the safety distance control between tower cranes, lack effective prevention of high-voltage live equipment collision risks, and the existing equipment is complicated to install, expensive, and has poor compatibility, making it difficult to be popularized to a wide range of crane operations. Therefore, how to overcome the shortcomings of the existing technology is a problem that needs to be solved in the current electric power construction technology field. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and provide a crane jib and live equipment safe collision avoidance risk assessment method. This method is simple and efficient, and can effectively monitor the distance between the crane jib and live equipment at the electric power construction site, quantitatively evaluate the distance safety level, and timely issue a danger warning when there is a safety risk.

[0006] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0007] A crane boom and live equipment safe collision avoidance risk assessment method, comprising the following steps:

[0008] Step (1), measure the electric field intensity by using an electric field sensor, and measure the distance L1 from the high-voltage live equipment to the test point according to the principle of near electric induction;

[0009] Step (2), install a laser emitting source and a laser reflecting device, and measure the radial length L2 of the crane boom by using the pulse laser time-of-flight measurement method;

[0010] Step (3), compare the distance L1 from the live high-voltage equipment to the test point with the safe distance L s1 , and calculate the risk coefficient K1;

[0011] Step (4), compare the radial length L2 of the crane boom with the safe threshold L s2 , and calculate the risk coefficient K2;

[0012] Step (5), calculate the comprehensive risk coefficient K ave according to the risk coefficients K1 and K2;

[0013] Step (6), determine the risk level based on the comprehensive risk coefficient K ave , and perform corresponding early warning.

[0014] Further, preferably, in step (1), a main electric field sensor is installed at the highest point of the boom; three auxiliary electric field sensors are uniformly arranged in the middle of the boom.

[0015] Further, preferably, when the three auxiliary electric field sensors are arranged, the interval between two adjacent sensors is 2 meters.

[0016] Further, preferably, in step (1), the calculation formula of the distance L1 from the high-voltage live equipment to the test point is as follows:

[0017]

[0018] Wherein, n represents the number of measurement points, L cj , E cj respectively represent the distance from the jth measurement point to the high-voltage live equipment and the electric field intensity measured at the point; E read represents the electric field intensity collected by the crane, and m and b are constants.

[0019] Further, preferably, in step (2), the laser emitting source is fixed at the intersection of the crane chassis and the boom, and the laser reflecting device is placed at the top of the boom.

[0020] Further, preferably, in step (2), the formula for calculating the radial length L2 of the crane boom is as follows:

[0021]

[0022] where c is the speed of light; N is the number of complete clock pulse periods spanned by the timing signal; f c is the frequency of the clock pulses; and are the phase differences of the start and end of the timing signal, respectively, relative to a certain reference clock pulse.

[0023] Further, preferably, in step (3), the specific method for calculating the risk coefficient K1 is as follows:

[0024]

[0025] where L s1 is the safe distance of the boom from the high-voltage live equipment.

[0026] Further, preferably, in step (4), the specific method for calculating the risk coefficient K2 is as follows:

[0027]

[0028] where L s2 is the pre-set radial length warning threshold of the boom.

[0029] Further, preferably, the specific method for step (5) is as follows:

[0030]

[0031] where α and β are the weight factors assigned to K1 and K2, respectively, and satisfy α+β=1.

[0032] Further, preferably, the specific method for step (6) is as follows:

[0033] When 60% < K ave , 30% < K ave ≤ 60%, 0 < K ave ≤ 30%, the alarm levels are High, Medium, and Low, respectively, for the audible and visual alarms; when the risk coefficient K ave is 0, it is in a safe state and no alarm is given.

[0034] In step (1) of the present application, the near electric induction utilizes the electric field generated by the high voltage equipment to make the induction device generate a voltage signal related to the electric field intensity, and after amplification, filtering and calibration, the signal can represent the electric field intensity. To ensure omnidirectional and high-precision electric field monitoring, the main electric field inductor is arranged at the highest point of the boom, and the selection of this position maximizes its sensitivity to the electric field changes of the surrounding high-voltage charged equipment. In the middle of the boom, three auxiliary electric field inductors are arranged, which work cooperatively to form a three-dimensional monitoring network.

[0035] The near electric induction distance measuring flow chart is shown in Figure 2 A rectangular coordinate system is established around the equivalent high-voltage charged equipment as shown in Figure 3 The ground is taken as the origin O, the parallel ground straight line is taken as the X axis, the vertical ground straight line is taken as the Y axis, and i represents the high-voltage charged equipment, wherein the P(x, y) point represents the coordinates of any point in the space around the high-voltage charged equipment. According to Gauss theorem, the unit equivalent charge q i of the high-voltage charged equipment at the i point generates an electric field intensity E i at the P(x, y) point, and is:

[0036]

[0037] In the formula, q i represents the charge amount of the high-voltage charged equipment at the i point, ε0 represents the vacuum dielectric constant, and L ip is the distance from the high-voltage charged equipment i to the P point.

[0038] It is calculated that:

[0039]

[0040] In actual engineering applications, it is more difficult to directly obtain the equivalent charge amount q i . In order to solve this problem, the present application adopts a practical calibration method, which aims to determine a key parameter, the proportional constant D, through one or more electric field intensity measurements at a known distance.

[0041]

[0042] At a known distance L c , the electric field intensity E c is measured, and then D=L c ·E c , D contains the charge amount information of the charged body and the distance influence factor of the electric field intensity. In order to make the obtained proportional coefficient more reliable, several groups can be measured and the average number can be obtained to determine the final proportional constant, wherein n represents the number of measurement points, L cj , and E cjrespectively, the distance from the jth measuring point to the high-voltage charged equipment and the electric field intensity measured at the point, the expression is as follows:

[0043]

[0044] And the unknown distance is inversely deduced by a proportional constant D, and L1 is used to represent:

[0045]

[0046] Meanwhile, the crane has high linearity to the power frequency electric field around the high-voltage line, so the linear correction method can be used to correct the electric field intensity collected when the crane is present to the electric field intensity when the crane is not present.Combined with formula (5), the corrected formula of the distance L1 from the high-voltage equipment to the test point is as follows:

[0047]

[0048] Wherein, n represents the number of measuring points, L cj , E cj respectively, the distance from the jth measuring point to the high-voltage charged equipment and the electric field intensity measured at the point, the expression is as follows: read E read represents the electric field intensity collected when the crane is present, and m and b are constants, and mE actual +b can be regarded as a linear transformation of the electric field intensity collected by the crane to eliminate possible system errors.

[0049] E read = mE actual +b

[0050] E s2 represents the electric field intensity after correction without the crane, that is, the corrected electric field intensity.

[0051] In step (1) of the present application, three auxiliary electric field sensors are uniformly arranged in the middle of the boom, so that the interval between adjacent sensors is kept at about 2 meters, to ensure omnidirectional monitoring effect.

[0052] In step (2) of the present application, the laser emitting source is fixed at the intersection of the crane chassis and the boom, and has the ability of omnidirectional 360° horizontal rotation with the chassis and 90° vertical swing up and down with the boom, so as to ensure that the laser emitting path always keeps consistent with the direction of the boom. The laser reflection device is arranged at the top of the boom, and can move radially with the boom, always keeping perpendicular relationship with the laser emitting path. Since the working space of the crane boom is a three-dimensional hemispherical region, only the radial length of the boom is taken as the judgment value of the safety warning system: if L2>L s2If yes, further evaluate the risk coefficient K2; otherwise, directly enter the comprehensive risk evaluation stage. In the formula, L2 is the radial length of the crane boom; L s2 Is the preset radial length of the boom warning threshold. A narrow pulse laser is selected as the transmission signal, and the time interval of the laser round trip is measured by means of high-speed electronic technology. Since the speed of light c is a constant, the value is 3.0×10 8 m / s, according to the time delay formula of laser transmission and reception, the radial length of the boom can be accurately calculated:

[0053]

[0054] The pulse laser time-of-flight measurement usually adopts the pulse counting method, which realizes the measurement of the time interval of the timing signal by counting the clock pulses between the timing start and end signals. However, the pulse laser time-of-flight measurement value has a certain timing error, and the sources of the pulse counting error are as shown in Figure 4 , A and B represent the clock pulse number, T1 represents the time interval from the rising edge of the timing start signal to the rising edge of the A clock pulse, T2 represents the time interval from the timing end signal to the next rising edge of the B clock pulse, and T X represents the time measurement result of the pulse counting method. It can be seen that the measurement error of the pulse counting method mainly comes from two aspects: coarse counting error and subdivision error. The coarse counting error is determined by the periodic characteristics of the timing signal Tx and the clock pulse, and the subdivision error is caused by the relative phase relationship of the timing signal Tx and the clock pulse. The final time interval can be modified by periodic compensation:

[0055]

[0056] Wherein, N represents the number of coarse counting, that is, the number of complete clock pulse periods crossed by the timing signal; f c is the frequency of the clock pulse; and are the phase difference of the timing signal start and end relative to a certain reference clock pulse, respectively. With the development of modern precision machining and radio measurement related technologies, the measurement of has reached very high accuracy, and by this way, the measurement error of the pulse counting method can be reduced as much as possible.

[0057] According to formula (7) and formula (8), the corrected radial length of the boom is:

[0058]

[0059] In step (3) of the present application, L s1The safe distance of the boom from the high-voltage live equipment (preferably set to 2 m, which can be adjusted according to the specific voltage level and working environment in actual application) is the minimum interval required to ensure the safety of personnel and the system when operating or arranging the equipment in a high-voltage environment.

[0060] The risk coefficient is defined as:

[0061]

[0062] K1 can reflect the relationship between the distance between the boom and the high-voltage equipment and the safety threshold, and the larger the value of K1, the higher the risk coefficient.

[0063] In step (4) of the present application, according to d = cΔt / 2, and the corrected Δt, the accurate value of the radial length L2 of the boom can be obtained, where c takes the speed of light 3.0×10 8 m / s, and the half-sphere space is a virtual area with the crane base as the center and a radius equal to the maximum extension length. If the safety threshold of the half-sphere space where the crane is located is L s2 (i.e. the pre-set radial length warning threshold of the boom), then the risk coefficient is defined as:

[0064]

[0065] K2 can reflect the relationship between the radial length of the boom and the safety threshold, and the larger the value of K2, the higher the risk coefficient. Considering the safety standard of the working environment, L s2 is usually set to 50 meters, but needs to be adjusted according to the specific application scenario (such as the maximum extension length of the crane).

[0066] In step (5) of the present application, the risk coefficient K1 obtained by the near-electricity induction technology and the risk coefficient K2 obtained by the laser radar ranging technology are combined, since both of them reflect the safety distance of the crane boom from the live equipment from different dimensions, a weighted average algorithm can be used to obtain a more reasonable risk coefficient:

[0067]

[0068] Where, α and β are the weight factors allocated to K1 and K2, respectively, and satisfy α+β=1. In the power construction site, α and β may involve the consideration of different risk factors, which are determined according to the specific construction environment. In the construction environment that pays more attention to the distance risk between the boom and the high-voltage equipment, α>β, preferably α>0.6.

[0069] K ave The larger the value, the higher the risk coefficient, which means that the construction environment is more dangerous.

[0070] In step (6) of the present application, the alarm level is divided into three levels,

[0071]

[0072] respectively, when 60% < K ave , 30% < K ave ≤ 60%, 0 < K ave ≤ 30%, the alarm levels are High, Medium, Low respectively, when the risk coefficient K ave is 0, the system is in a safe state and no alarm is given.

[0073] The present application first utilizes the near electric induction technology to monitor the electric field intensity between the crane boom and the high voltage equipment, which is monitored by the main electric field sensor at the highest point of the boom and three auxiliary electric field sensors at the middle of the boom to form a comprehensive electric field monitoring network.

[0074] Secondly, the proportional constant D is determined by the electric field intensity measurement value at the known distance to inversely deduce the unknown distance L1, and the linear correction formula is used to correct the electric field intensity with crane influence to the electric field intensity without crane influence to calculate the corrected distance.

[0075] Then, the safety distance L S1 is set, the difference AL between the current distance L1 and L S1 is calculated, and the risk coefficient K1 reflecting the distance between the boom and the high voltage equipment and the safety threshold is defined.

[0076] Then, the laser round trip time is measured, and the radial length L2 of the boom is calculated according to the speed of light, which is compared with the pre-set boom radial length warning threshold L s2 to determine whether it is close to the high voltage equipment; the laser emitting source fixed at the intersection of the crane chassis and the boom and the laser reflecting device placed at the top of the boom are used to measure the laser round trip time to determine the radial length L2 of the boom, the boom radial length warning threshold L S2 is set, and the risk coefficient K2 reflecting the relationship between the radial length of the boom and the safety threshold is calculated.

[0077] Furthermore, the risk coefficients K1 and K2 obtained by combining the near electric induction technology and the laser radar ranging technology are used to obtain the comprehensive risk coefficient by using the weighted average algorithm, wherein alpha and beta are weight factors, and alpha + beta = 1

[0078] Finally, the alarm level is determined according to the comprehensive risk coefficient, which is divided into three levels of High, Medium and Low, and no alarm is given when the risk coefficient is zero.

[0079] In the present application, the positions of the main electric field sensor and the auxiliary electric field sensor are selected to maximize the sensitivity of the electric field change of the high voltage equipment.

[0080] In the present application, the laser emission source and the reflection device ensure that the laser emission path is always consistent with the direction of the boom, a narrow pulse laser signal is used and the round-trip time is measured, and the radial length of the boom is calculated based on the speed of light c=3.0*10 8 m / s. Preferably, the laser radar technology uses a narrow pulse laser as the emission signal and measures the round-trip time of the laser using high-speed electronics to achieve accurate measurement of the radial length of the boom.

[0081] In the present application, the calculation of the safety factor is based on the actual distance between the boom and the high-voltage equipment and the radial length of the boom, as well as the corresponding safety threshold.

[0082] In the present application, the alarm mechanism sets different alarm levels according to the level of the safety factor to remind the operator to pay attention to the safety distance between the boom and the high-voltage equipment.

[0083] In the present application, the proportionality constant D is obtained by measuring the electric field strength Ec at a known distance Lc, D=Lc·Ec, which is used to deduce the unknown distance L1.

[0084] In the present application, the light radar technology is combined with the near electric induction technology to form a complete and efficient risk assessment system for the safety of the crane boom and the live equipment.

[0085] The weight factors alpha and beta in the weighted average algorithm are determined according to the specific construction environment to balance the safety distance assessment in different dimensions.

[0086] The present application provides a risk assessment method for preventing the collision of a crane boom with live equipment, which integrates near electric induction technology and laser ranging technology to assess the safety distance between the boom and live equipment in real time during hoisting operations, effectively preventing collision accidents and ensuring the safety of power construction sites.

[0087] The present application method has significant practical value and far-reaching safety significance for protecting high-risk operating equipment such as cranes from dangerous live equipment. This not only helps to reduce the accident rate, but also promotes the overall improvement of safety standards.

[0088] Compared with the prior art, the present application has the following beneficial effects:

[0089] (1) Significantly improve the calculation accuracy and accuracy: the present application integrates near electric induction technology and laser radar ranging technology to innovatively improve the evaluation accuracy of the safety distance between the crane boom and live equipment. Specifically, the near electric induction technology optimizes the collection and processing of electric field strength signals, with an error range of ±10% reduced to within ±3% compared to traditional methods. The laser radar technology ensures high accuracy in distance measurement. This dual technology integration significantly reduces false positives and false negatives, improving the reliability of risk assessment.

[0090] (2)Optimization of algorithm efficiency and response speed: The weighted average algorithm adopted not only integrates the data of electric field induction and laser ranging, but also flexibly adapts to the needs of different construction environments through weight distribution. This method greatly shortens the processing time from data collection to risk assessment, realizes instant feedback within 1 second, enables operators to quickly respond to potential collision risks, thereby not only protecting personnel safety, but also reducing economic losses and construction delays caused by accidents.

[0091] (3)Improvement of practicality and compatibility of anti-collision system: The present invention overcomes the problems of complex installation, high cost and poor compatibility of traditional anti-collision systems. The combination of near electric induction technology and laser radar creates an intelligent and practical evaluation model suitable for various complex operating environments. Its simple installation, maintenance convenience and low use cost make the system more easily applied to crane operations, greatly improving the compatibility and market penetration of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0092] Figure 1 The logic judgment diagram of the crane boom and live equipment safety collision avoidance risk assessment method of the present invention;

[0093] Figure 2 The near electric induction ranging flowchart;

[0094] Figure 3 The high-voltage live equipment processing coordinate diagram;

[0095] Figure 4 The principle of pulse count error generation;

[0096] Figure 5 The proportional constant D call result;

[0097] Figure 6 The Eactal and Eread linear expression call result;

[0098] Figure 7 The flowchart of the crane boom and live equipment safety collision avoidance risk assessment method of the present invention. DETAILED DESCRIPTION

[0099] The present invention will be further described in detail below in conjunction with examples.

[0100] Those skilled in the art will understand that the following examples are only for illustration of the present invention and should not be considered as limiting the scope of the present invention. If the specific technology or conditions are not specified in the examples, the technology or conditions described in the literature in the art or according to the product instructions are used. If the manufacturer of the materials or equipment is not specified, it is a conventional product that can be obtained by purchase.

[0101] The present invention aims to solve a key safety issue in current crane operations - precise assessment and effective prevention of high-voltage live equipment touch risk. In view of the limitations of traditional anti-collision systems, such as complex installation process, high cost and poor device compatibility, we propose an innovative solution that combines advanced near-electric induction technology and high-precision laser radar to build an intelligent calculation model for accurately assessing the collision risk between the crane boom and high-voltage live equipment. The core of this method is a mean square normalized statistical evaluation technique that can accurately quantify potential collision threats. By monitoring the difference (ΔL) between the actual distance and the preset safety distance and comparing it with the safety distance, a risk coefficient reflecting the true distance and risk level is calculated. The purpose is to monitor the proximity of the boom to live equipment in real time and immediately issue a warning signal.

[0102] Embodiment 1

[0103] As shown in Figure 1 and Figure 7 , a crane boom and live equipment safety collision avoidance risk assessment method includes the following steps:

[0104] Step (1), measure the electric field strength using an electric field sensor, and according to the near-electric induction principle, calculate the distance L1 from the high-voltage live equipment to the test point;

[0105] Step (2), install a laser emitter and a laser reflector, and use the pulse laser time-of-flight measurement method to measure the radial length L2 of the crane boom;

[0106] Step (3), compare the distance L1 from the live high-voltage equipment to the test point with the safety distance L s1 , and calculate the risk coefficient K1;

[0107] Step (4), compare the radial length L2 of the crane boom with the safety threshold L s2 , and calculate the risk coefficient K2;

[0108] Step (5), calculate the comprehensive risk coefficient K ave according to the risk coefficients K1 and K2;

[0109] Step (6), determine the risk level based on the comprehensive risk coefficient K ave , and issue a corresponding warning.

[0110] Embodiment 2

[0111] As shown in Figure 1 and Figure 7 , a crane boom and live equipment safety collision avoidance risk assessment method includes the following steps:

[0112] Step (1), measure the electric field intensity by using electric field sensor, according to the principle of near electric induction, measure the distance L1 from the high-voltage charged equipment to the test point;

[0113] Step (2), install laser emitting source and laser reflection device, measure the radial length L2 of the crane boom by using pulse laser time-of-flight measurement method;

[0114] Step (3), compare the distance L1 from the high-voltage charged equipment to the test point and the safety distance L s1 , calculate the risk coefficient K1;

[0115] Step (4), compare the radial length L2 of the crane boom and the safety threshold L s2 , calculate the risk coefficient K2;

[0116] Step (5), according to the risk coefficients K1 and K2, calculate the comprehensive risk coefficient K ave ;

[0117] Step (6), based on the comprehensive risk coefficient K ave , determine the risk level and give corresponding warning.

[0118] In step (1), install the main electric field sensor at the highest point of the boom; evenly arrange three auxiliary electric field sensors in the middle of the boom.

[0119] In step (1), the calculation formula of the distance L1 from the high-voltage charged equipment to the test point is as follows:

[0120]

[0121] Wherein, n represents the number of measurement points, L cj , E cj respectively represent the distance from the jth measurement point to the high-voltage charged equipment and the electric field intensity measured at the point; E read represents the electric field intensity collected by the crane, and m and b are constants.

[0122] In step (2), the laser emitting source is fixed at the intersection point of the crane chassis and the boom, and the laser reflection device is placed at the top of the boom.

[0123] In step (2), the calculation formula of the radial length L2 of the crane boom is as follows:

[0124]

[0125] Wherein, c is the speed of light; N is the number of complete clock pulse periods crossed by the timing signal; f c is the frequency of the clock pulse; and respectively the phase difference of the start and end of the timing signal relative to a reference clock pulse.

[0126] In step (3), the specific method for calculating the risk coefficient K1 is:

[0127]

[0128] wherein L s1 is the safety distance of the boom from the high-voltage live equipment.

[0129] In step (4), the specific method for calculating the risk coefficient K2 is:

[0130]

[0131] wherein L s2 is a pre-set radial length warning threshold of the boom.

[0132] The specific method of step (5) is:

[0133]

[0134] wherein a and b are weight factors assigned to K1 and K2 respectively, and satisfy a+b=1.

[0135] The specific method of step (6) is:

[0136] When 60% < K ave , 30% < K ave ≤ 60%, 0 < K ave ≤ 30%, the alarm levels are High, Medium, and Low respectively for the audible and visual alarms; when the risk coefficient K ave is 0, it is in a safe state and no alarm is given.

[0137] Example 3

[0138] As shown in Figure 1 and Figure 7 , a crane boom and live equipment safety collision avoidance risk assessment method includes the following steps:

[0139] Step (1), measure the electric field intensity using an electric field sensor, and measure the distance L1 from the high-voltage live equipment to the test point according to the electric field induction principle;

[0140] Step (2), install a laser emitter and a laser reflector, and measure the radial length L2 of the crane boom using the pulse laser time-of-flight measurement method;

[0141] Step (3), compare the distance L1 from the live high-voltage equipment to the test point with the safety distance L s1 , and calculate the risk coefficient K1;

[0142] Step (4), compare the radial length L2 of the crane jib and the safety threshold L s2 , calculate the risk coefficient K2;

[0143] Step (5), according to the calculation of risk coefficients K1, K2, the comprehensive risk coefficient K ave is obtained.

[0144] Step (6), based on the comprehensive risk coefficient K ave , the risk level is determined, and the corresponding warning is given.

[0145] In step (1), the main electric field sensor is installed at the highest point of the jib; three auxiliary electric field sensors are evenly arranged in the middle of the jib. When arranging the three auxiliary electric field sensors, the interval between the adjacent two sensors is 2 meters.

[0146] In step (1), the distance L1 from the high-voltage live equipment to the test point is calculated as follows:

[0147]

[0148] Wherein, n represents the number of measurement points, L cj , E cj respectively represent the distance from the jth measurement point to the high-voltage live equipment and the electric field strength measured at the point; E read represents the electric field strength collected by the crane, and m and b are constants.

[0149] In step (2), the laser emission source is fixed at the intersection of the crane chassis and the jib, and the laser reflection device is placed at the top of the jib.

[0150] In step (2), the radial length L2 of the crane jib is calculated as follows:

[0151]

[0152] Wherein, c is the speed of light; N is the number of complete clock pulse periods crossed by the timing signal; f c is the frequency of the clock pulse; and are the phase difference of the timing signal starting and ending respectively relative to a certain reference clock pulse.

[0153] In step (3), the specific method for calculating the risk coefficient K1 is:

[0154]

[0155] Wherein, L s1 is the safety distance of the jib from the high-voltage live equipment, which is preferably set to 2m.

[0156] In step (4), the specific method for calculating the risk coefficient K2 is:

[0157]

[0158] wherein L s2 is a pre-set radial length warning threshold of the crane boom, preferably set to 50 meters.

[0159] The specific method of step (5) is:

[0160]

[0161] wherein a and b are weight factors assigned to K1 and K2 respectively, and satisfy a+b=1, preferably a>0.6.

[0162] The specific method of step (6) is:

[0163] When 60% < K ave , 30% < K ave ≤ 60%, 0 < K ave ≤ 30%, the alarm levels are High, Medium, and Low respectively, and the audible and visual alarms are triggered; when the risk coefficient K ave is 0, it is in a safe state and no alarm is triggered.

[0164] Example of application

[0165] The following is an example of using the crane boom and live equipment safety collision risk assessment method described in the present application to assess the risk level of a crane boom of a 7.5kV power transmission line in a certain fixed hemispherical space during construction work, which includes the following steps:

[0166] Step (1), in engineering practice, when facing high-voltage live equipment, directly measuring its linear charge density q i is a challenge. In order to overcome this difficulty, a calibration measurement procedure is implemented. In this example, the corresponding electric field intensity is measured at distances of 1m, 2m, 3m, 4m, and 5m from the high-voltage live equipment, and a Python script is used to calculate the proportional constant D at different distance points. According to the call results as shown in Figure 5 , the proportional constant D=7482 is obtained. Based on the measured electric field data with and without the crane, the linear expression between E actual and E read is obtained, and the call results are as shown in Figure 6 , wherein the slope m≈0.5197 and the intercept b≈4238. The correction process is described in detail: assuming that under the action of the crane, the measured electric field intensity E read is 6kV / m, the actual electric field intensity without the influence of the crane is calculated to be 6.5kV / m using the above correction formula.

[0167] E actual = 0.1597E read + 4238 = 0.1597 x 6000 V / m + 4238 V / m = 5196.2 V / m

[0168] According to formula (2)

[0169]

[0170] Figure 6 Call the result for the linear expression of Eactal and Eread.

[0171] Step (2), under the 7.5KV high-voltage transmission line of a certain substation, the crane is working in the hemispherical space, L S2 is the pre-set jib radial length warning threshold in this environment, the value is 50 meters, the pulse laser transmitter is installed at the base of the crane, the frequency f c is adjusted to 10MHz, through radio measurement, the phase difference of the start and end of the timing signal relative to the given reference clock pulse is 4.9°, and we observed 3 complete cycles in this measurement.

[0172] First, convert the angle 4.9° to radians, which is about 0.0855π, and calculate the time interval:

[0173]

[0174] According to the principle of laser time-of-flight measurement, the measured value can be brought in to obtain the jib radial length of the crane under the current working condition:

[0175]

[0176] Step (3), set a safety distance L s1 = 2m, L1 < L s1 , where L1 represents the calculated current distance. Calculate the risk coefficient K1:

[0177]

[0178] Step (4), given the pre-set jib radial length warning threshold L s2 in this environment, the value is 45 meters, calculate the risk coefficient K2:

[0179]

[0180] Step (5), considering the collision risk between the crane boom and the live equipment in this construction environment, K1 is directly related to the actual distance between the boom and the high-voltage equipment, which is the most critical factor to avoid collision, we set alpha = 0.7, beta = 0.3, according to formula (8) we can get the overall risk coefficient:

[0181]

[0182] Step (6), according to the risk coefficient calculation result, the safety distance risk level between the crane boom and the live equipment is located in 0% < K ave ≤30%, the risk level is low, but there is still risk, and an audible and visual alarm will be issued to remind the operator.

[0183] In the current power construction site, the traditional anti-collision system for preventing the collision between the crane boom and the live equipment generally has the following problems: first, the installation is complex, the traditional system needs a complex hardware installation and calibration process, which leads to a long deployment period and high cost; second, the cost is too high, because it depends on high-performance sensors and other high-end components, the overall system procurement, installation and maintenance cost is expensive; third, the compatibility is poor, the same brand and model of crane may not be directly adapted to these anti-collision systems, which limits its wide application. And the present application uses near electric induction technology and laser radar ranging technology, first, through the optimization of sensor design and the introduction of correction algorithm, the data acquisition accuracy is greatly improved, and the error range is greatly reduced; second, it can complete the whole process from data acquisition to early warning response in less than one second, greatly improving the efficiency; finally, the application of the present application in the implementation example shows that the method described in the present application can reduce the system cost, and because of its simple installation and modular design, it greatly improves the compatibility and market acceptance of other systems.

[0184] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above examples, the above examples and descriptions in the specification are only to illustrate the principles of the present application, without departing from the spirit and scope of the present application, the present application can have various changes and improvements, these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for assessing the risk of collision avoidance between a crane jib and live equipment, characterized in that, It comprises the following steps: Step (1), measuring the electric field intensity by using an electric field sensor, and calculating the distance L1 from the high-voltage charged equipment to the test point according to the principle of near electric induction; Step (2), installing a laser emitting source and a laser reflecting device, and measuring the radial length L2 of the crane boom by using the pulse laser time-of-flight measurement method; Step (3), compare the distance L1 from the charged high-voltage equipment to the test point and the safety distance L s1 , calculate the risk coefficient K1; Step (4), comparing the radial length L2 of the crane boom with a safety threshold L s2 , calculating a risk coefficient K2; Step (5), according to the risk coefficients K1, K2, the comprehensive risk coefficient K is calculated ave ; Step (6), based on the comprehensive risk coefficient K ave Determine the risk level and make the corresponding early warning.

2. Crane jib and live equipment safe risk of collision avoidance assessment method according to claim 1, characterized in that, In step (1), the main electric field sensor is installed at the highest point of the boom, and three auxiliary electric field sensors are evenly arranged in the middle of the boom.

3. Crane jib and live equipment safe risk of collision avoidance assessment method according to claim 2, characterized in that, When the three auxiliary electric field sensors are arranged, the interval between two adjacent sensors is 2 meters.

4. The method of assessing the risk of collision avoidance for a crane jib and live equipment according to claim 1, characterized in that, In step (1), the calculation formula of the distance L1 from the high-voltage charged equipment to the test point is as follows: Wherein, n represents the number of measurement points, L cj , E cj respectively represent the distance from the jth measurement point to the high-voltage charged equipment and the electric field intensity measured at the point; E read represents the electric field intensity collected by the crane, and m and b are constants.

5. The method of assessing the risk of collision avoidance for a crane jib and live equipment according to claim 1, characterized in that, In step (2), the laser emitting source is fixed at the intersection point of the crane chassis and the boom, and the laser reflecting device is placed at the top of the boom.

6. The method of assessing the risk of collision avoidance for a crane jib and live equipment according to claim 1, characterized in that, In step (2), the calculation formula of the radial length L2 of the crane boom is as follows: where c is the speed of light; N is the number of complete clock pulse periods spanned by the timing signal; f c is the frequency of the clock pulses; and are the phase differences of the start and end of the timing signal, respectively, relative to some reference clock pulse.

7. The method of assessing the risk of collision avoidance for a crane jib and live equipment according to claim 1, characterized in that, In step (3), the specific method for calculating the risk coefficient K1 is as follows: wherein L s1 is the safe distance of the boom from the high-voltage live equipment.

8. The method of assessing the risk of collision avoidance for a crane jib and live equipment according to claim 1, characterized in that, In step (4), the specific method for calculating the risk coefficient K2 is as follows: wherein L s2 is a pre-set threshold of the radial length of the boom.

9. The method of assessing the risk of collision avoidance for a crane jib and live equipment according to claim 1, characterized in that, The specific method of step (5) is as follows: Wherein, α and β are the weight factors allocated to K1 and K2 respectively, and satisfy α+β=1.

10. The method of assessing the risk of collision avoidance for a crane jib and live equipment safety according to claim 1, characterized in that, The specific method of step (6) is as follows: When 60% < K ave , 30% < K ave , 0 < K ave , the alarm levels are High, Medium, Low, respectively, and the sound and light alarm is triggered; when the risk coefficient K ave is 0, the system is in a safe state and no alarm is triggered.

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