High-precision calculation method for weighing feed tower of farm under wind load condition

Abstract

The application provides a high-precision calculation method for weighing a feed tower of a farm under wind load, and belongs to the technical field of weight calculation methods; the method is realized through the following steps: determining the self weight of the feed tower, the total weight after adding feed, and the static support force of each supporting leg; measuring the wind direction and dividing the supporting legs into a windward group and a leeward group according to the vertical symmetry plane of the center of the feed tower perpendicular to the wind direction; calculating the vertical distance from each supporting leg of the windward group and the leeward group to the symmetry plane, combining the wind speed to calculate the wind load and the overturning moment to establish a mathematical model of the supporting leg counterforce under wind load, and obtaining the dynamic support force of each supporting leg; superimposing the static support force and the dynamic support force of each supporting leg to obtain the estimated support force of each supporting leg; performing filtering calculation on the estimated support force of each supporting leg under wind load and the real-time measured support force of each supporting leg to obtain accurate wind load dynamic support force; and subtracting the accurate wind load dynamic support force and the self weight of the feed tower to obtain the actual accurate weight of the feed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of weight calculation method, and particularly relates to a high-precision calculation method for weighing a feed tower of a farm under wind load conditions. BACKGROUND

[0002] The feed tower is usually designed as a high-rise structure, bears a large amount of material weight and is affected by the external environment, especially wind. As one of the external loads, wind load acts on the structure of the feed tower for a long time, which may cause vibration and deformation of the structure, thereby affecting the precision of the weighing system of the feed tower. The weighing system of the feed tower usually relies on the reaction force of the supporting leg to measure the weight of the feed, and the deformation of the supporting leg caused by the wind load will change the distribution of the reaction force of the supporting leg;

[0003] For example, the feed precise weighing calculation method of the farm in Chinese patent CN117824809A: through data acquisition and preprocessing and Kalman filter optimization, high-precision measurement of dynamic and static weighing of feed is realized. The main technical process is as follows: first, the weighing data is collected by the sensor, converted into the initial weight value after amplification and multi-channel summation, and then the original data fluctuation is reduced by using the sliding mean filter; subsequently, the Kalman state equation is established for the three states of static load, feeding and unloading, and the weight is dynamically optimized by combining the observation equation, the prior error covariance matrix and the gain coefficient, and finally the accurate weight is output and the error covariance matrix is updated to support the next period calculation; for the dynamic process such as feeding and unloading of the feed, the corresponding Kalman state equation is established by distinguishing the static load, feeding and unloading states, which breaks through the limitation of the traditional method that it is difficult to measure the dynamic weight;

[0004] However, under the wind load condition, the feed tower will vibrate or sway, causing the data collected by the sensor to contain additional vibration noise; but the filter and Kalman equation of this method do not design a correction mechanism for wind load interference, which will cause the measurement accuracy to decrease under the wind load condition; and the prediction error variance and observation error variance in Kalman filtering need to be calibrated through multiple tests, if the type of feed or the environment of the farm changes, the parameters need to be adjusted, otherwise the precision may fluctuate; in addition, the sliding mean filter reduces noise by averaging the data in the window, but if the window size is set too large, the response to the sudden change of feeding and unloading speed will be delayed, affecting the timeliness of measuring the instantaneous dynamic weight;

[0005] Therefore, under the existing technology, the feed can only be weighed under the condition of no wind load, and the weight of the feed during feeding or unloading is measured. Due to the limitation of the calculation method of the sensor measurement signal, the accuracy of the output data is not high; and the dynamic monitoring of the feed under the wind load condition. SUMMARY

[0006] The application provides a high-precision calculation method for weighing a feed tower of a farm under wind load conditions.

[0007] To achieve the above object, the technical scheme adopted by the present application is:

[0008] A high-precision calculation method for weighing a feed tower in a farm under wind load conditions, comprising a feed tower, the feed tower adopts an even multiple of leg structures; the number of legs is n, n>1, and the specific steps are as follows:

[0009] S1: determining the self-weight of the feed tower, the total weight of the feed tower and the feed, and the static support force of each leg of the feed tower under no wind load;

[0010] S2: measuring the wind direction and dividing the legs of the feed tower into windward groups and leeward groups according to the wind direction; fitting all the legs into two or more symmetrical virtual leg structures along the wind direction; and establishing a virtual leg dynamic support force distribution model of the feed tower under wind load conditions to obtain the dynamic support force of each leg;

[0011] Wherein, the virtual leg dynamic support force distribution model of the feed tower under wind load conditions is established to obtain the dynamic support force of each leg, specifically: measuring the wind direction and dividing the legs of the feed tower into windward groups and leeward groups according to the wind direction; according to the symmetry of the arrangement of the legs of the feed tower, all the legs are fitted into two virtual leg structures symmetrical to the symmetrical neutral plane, including windward virtual legs and leeward virtual legs; the legs of the feed tower are simplified into a statically indeterminate structure to obtain the dynamic support force of each leg;

[0012] S3: superimposing the static support force and the dynamic support force of each leg to obtain the estimated support force of each leg; using the estimated support force of each leg under wind load and the real-time measured leg support force of each leg to perform filtering calculation to obtain the accurate wind load dynamic total support force; the accurate wind load dynamic total support force minus the static support force of each leg to obtain the accurate total wind load dynamic support force of the feed tower;

[0013] S4: deducting the accurate wind load dynamic support force and the self-weight of the feed tower from the total weight of the feed tower and the feed to obtain the actual accurate weight of the feed.

[0014] As a preferred, in step S1, the self-weight of the feed tower, the total weight of the feed tower and the feed, and the static support force of each leg of the feed tower under no wind load are determined, specifically:

[0015] According to the force sensors arranged at the bottom of each leg of the feed tower, under no wind environment, ensure that the feed tower is placed horizontally, and the bottom of the leg is not loose or suspended; if the feed tower is empty, record the self-weight G 塔体 of the feed tower, and measure the diameter of the feed tower, the height of the feed tower;

[0016] According to the force sensor arranged at the bottom of each leg of the silo, the reaction force data of all legs under no wind load is collected, the average value is obtained by continuous sampling for 10 times, and the static support force of each leg is obtained ; the algebraic sum of the reaction forces of all legs is calculated ; .

[0017] As preferred, in step S2, the wind direction is measured and the legs of the silo are divided into windward group and leeward group according to the wind direction; all legs are fitted into two or more symmetrical virtual leg structures along the wind direction, and a virtual leg dynamic support force distribution model of the silo under wind load is established, which is specifically:

[0018] A wind speed sensor and a wind direction sensor are installed near the silo to collect wind speed v and wind direction in real time; the wind load force and the overturning moment M are calculated according to the wind speed v;

[0019] According to the silo structure drawing and the wind direction, the legs are divided into windward group on the windward side and leeward group on the leeward side according to the vertical symmetry plane passing through the center of the silo perpendicular to the wind direction; the legs are sequentially numbered as the first to the n-th;

[0020] The vertical distance of each leg to the vertical symmetry plane of the center of the silo perpendicular to the wind direction is measured; and the vertical distance of the windward leg and the leeward leg is ensured to be one-to-one corresponding.

[0021] As preferred, according to the silo structure drawing and the wind direction, the legs are divided into windward group on the windward side and leeward group on the leeward side according to the vertical symmetry plane passing through the center of the silo perpendicular to the wind direction; the legs are sequentially numbered as the first to the n-th, which is specifically:

[0022] According to the silo structure drawing and the wind direction, the north direction is set as the initial zero degree position of the wind direction sensor, and the Y axis positive direction is set on the horizontal plane; the X axis positive direction perpendicular to the Y axis on the horizontal plane is set, and the horizontal plane is further divided into four quadrants according to the conventional plan; meanwhile, the leg number is determined, which is sequentially numbered as the first to the n-th in the counterclockwise direction from the north direction, and the initial included angle of each leg with the north direction is determined according to the installation position; the vertical symmetry plane passing through the center of the silo perpendicular to the wind direction is determined as the neutral symmetry plane, which divides the legs into windward group on the windward side and leeward group on the leeward side; and the leg number falling into the windward group and the leeward group is further determined.

[0023] As preferred, the vertical distance of each leg to the vertical symmetry plane of the center of the silo perpendicular to the wind direction is measured; and the vertical distance of the windward leg and the leeward leg is ensured to be one-to-one corresponding, which is specifically:

[0024] The vertical distance of each leg to the vertical symmetry plane of the tower center perpendicular to the wind direction is determined as follows: first, the projection of each leg position on the horizontal plane is determined, and the line connecting the projection point with the projection of the tower center on the horizontal plane is equal to the included angle between the tower radius R and the Y axis , The included angle is 0-180°, and the included angle β between the neutral symmetry plane and the north direction is further determined, and the included angle β is 0-90°;

[0025] Secondly, when the northeast wind acts on the tower, the neutral plane is located in the second and fourth quadrants, the distance between the leg of the leeward group and the neutral plane =Rsin( ), the distance between the leg of the windward group and the neutral plane =Rsin( ), when the southwest wind, the distance between the leg of the windward group and the neutral plane =Rsin( ), the distance between the leg of the leeward group and the neutral plane =Rsin( );

[0026] When the southeast wind acts on the tower, the neutral plane is located in the first and third quadrants, the distance between the leg of the windward group and the neutral plane =Rsin( ), the distance between the leg of the windward group and the neutral plane =Rsin( ), when the northwest wind, the distance between the leg of the leeward group and the neutral plane =Rsin( ), the distance between the leg of the windward group and the neutral plane =Rsin( ).

[0027] As a preferred, the tower leg is simplified as a statically indeterminate structure, and the dynamic support force of each leg is obtained, which is specifically:

[0028] After analyzing the statically indeterminate structure by force method, the tower leg is simplified as a statically indeterminate structure, and the redundant constraint reaction force is taken as an unknown quantity, and the deformation coordination equation is established:

[0029]

[0030] Among them, is the unit redundant unknown constraint reaction force =1 when acting alone on the basic structure, the displacement caused along ; is the displacement along direction when the wind load acts alone;

[0031] Solving the deformation compatibility equation , combined with the static equilibrium equation to get the dynamic support force of the upwind group and the upwind group .

[0032] As a preferred, the deformation compatibility equation is specifically:

[0033]

[0034] Wherein, is the diameter of the tower, is the height of the tower, is the wind load.

[0035] As a preferred, the dynamic support force of the upwind group and the upwind group is obtained by combining the static equilibrium equation and , specifically:

[0036] The force method regular equation can be solved to get the support constraint reaction force According to the principle of static equilibrium, the equation is:

[0037] + =0;

[0038] The virtual leg of the leeward group generates stress along the leg direction due to wind load:

[0039] ;

[0040] The virtual leg of the upwind group generates stress along the leg direction due to wind load:

[0041] ;

[0042] According to the above formula, the support constraint reaction force and can be solved; then in turn, each leg to the vertical symmetry plane of the tower perpendicular to the wind direction is in turn , , … … , according to the vertical distance of the tower leg to the neutral plane of the tower , distributed to n legs, the dynamic support force of the leeward group leg is , wherein =1~n; then the dynamic support force of the leeward group leg is The formula is:

[0043] ;

[0044] The dynamic support force of the upwind group leg is The formula is:

[0045] .

[0046] As preferred, in step S3, the estimated support force of each leg is obtained by superimposing the static support force and the dynamic support force of each leg, specifically:

[0047] The estimated support force of the leg .

[0048] As preferred, in step S3, the estimated support force of each leg is obtained by superimposing the static support force and the dynamic support force of each leg, specifically:

[0049] The estimated support force of the upwind leg ; The estimated support force of the downwind leg .

[0050] As preferred, in step S3, the precise wind load dynamic support force is calculated by filtering the estimated support force of each leg under wind load and the real-time measured support force of each leg, specifically:

[0051] The real-time support force of the upwind leg is obtained by the pressure sensor installed at the bottom of each leg of the material tower ;

[0052] The precise wind load dynamic support force is calculated by Kalman filtering, and the specific operation is as follows:

[0053] The prior estimation formula is constructed:

[0054] ;

[0055] Wherein, is the state transition matrix from to ;

[0056] is the control matrix from to ;

[0057] is the Gaussian white measurement noise vector;

[0058] is the state parameter vector at : The vector composed of

[0059] The prior error covariance matrix formula is constructed :

[0060] ;

[0061] wherein, Q is the error covariance matrix of the system process noise;

[0062] wherein the operation formula of the Kalman filter gain is as follows :

[0063] ;

[0064] wherein, is the observation matrix of the object, is the covariance error matrix of the noise in the measurement data;

[0065] The construction Kalman gain is calculated formula:

[0066] ;

[0067] wherein, is the observation matrix; Specifically, the measurement value of each leg force sensor is composed of; ;

[0068] By combining the Kalman gain, the prior covariance and the observation matrix, the posterior covariance matrix required for the next filtering iteration is calculated according to the formula:

[0069] ;

[0070] The optimal estimation of the last filtering iteration time is taken as the prior estimation, the current state is predicted, and then the real-time measured leg support force is used to correct the predicted value to obtain the optimal estimation; iteration finally obtains the accurate total support force of each leg under the wind load condition , and further, the dynamic support force of each leg caused by the wind load ; is the static support force of each leg alone;

[0071] The algebraic sum of all leg counter forces is calculated: ;

[0072] The total dynamic support force caused by the wind load is calculated: ;

[0073] The net weight of the feed in the silo is calculated: .

[0074] Compared with the prior art, the advantages and positive effects of the present application are that:

[0075] The application discloses a high-precision calculation method for feed tower weighing in a farm under wind load, which considers the influence of outdoor wind load and provides a method for accurately weighing feed in the farm all day long.

[0076] The legs are grouped by using the symmetry principle, data acquisition and noise reduction are only needed for the n windward legs, the leeward legs directly reuse the results, the amount of sensors and calculation is reduced by 50%, and the hardware cost and operation load are reduced.

[0077] In addition, the high-precision calculation method for feed tower weighing in a farm under wind load is suitable for the feed tower of the farm with an even multiple of leg structures, can realize accurate weighing under various wind load working conditions such as gradually changing wind, random wind and gust, and does not need to additionally transform the structure of the feed tower and is easy to integrate into an existing weighing system. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0079] Figure 1 It is a simplified diagram of the 6-leg feed tower of the present application;

[0080] Figure 2 It is a 2-leg lateral force diagram of the present application;

[0081] Figure 3 It is a 2-leg lateral force state diagram of the present application;

[0082] Figure 4This is a symmetrical load force diagram of the present invention;

[0083] Figure 5 This is a force diagram of the antisymmetric load of the present invention;

[0084] Figure 6 This is a stress diagram of the overall structure of the feed tower of the present invention;

[0085] Figure 7 This is a stress diagram of the left half of the material tower structure of the present invention. Detailed Implementation

[0086] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0087] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0088] Example 1, as Figures 1-3 As shown in the present application, a high-precision calculation method for weighing a feed tower in a farm under wind load conditions includes a feed tower, wherein the feed tower adopts a support structure with an even number of legs; the number of legs is n, n>1, and in this embodiment, n=8, that is, the feed tower has a total of eight legs;

[0089] The specific steps are as follows:

[0090] S1: Determine the weight of the tower itself, the total weight of the tower and feed, and the static support force of each leg of the tower when there is no wind load, based on the force sensor installed at the bottom of each support leg.

[0091] S2: Measure the wind direction and divide the tower legs into windward and leeward groups according to the wind direction; fit all legs into two left-right symmetrical virtual leg structures along the wind direction, and establish a dynamic support force distribution model of the tower virtual legs under wind load conditions to obtain the dynamic support force of each leg.

[0092] Specifically, a dynamic support force distribution model for the virtual legs of the material tower under wind load conditions was established to obtain the dynamic support force of each leg. This involved: measuring the wind direction and dividing the tower legs into a windward group and a leeward group based on the wind direction; fitting all legs into two virtual leg structures symmetrical about a symmetrical neutral plane based on the symmetry of the tower leg arrangement, including a windward virtual leg group and a leeward virtual leg group; and simplifying the tower legs into a first-order statically indeterminate structure to obtain the dynamic support force of each leg.

[0093] Wherein, "fitting all the legs into two or so symmetrical virtual leg structures along the wind direction" utilizes the symmetry theory, which can effectively simplify the analysis process, especially when the design of the tower leg often adopts a symmetrical layout in the face of structures with geometric symmetry or load symmetry, which makes the entire tower present certain symmetry under the action of static load; any load acting on the symmetrical structure can be divided into symmetrical load and anti-symmetrical load for calculation. Then, the results of the symmetrical and anti-symmetrical structures under the action of any load are superimposed to obtain the result of the original symmetrical structure under the action of any load. Under the action of symmetrical load, the deformation is symmetrical, the bending moment diagram and the axial force diagram are symmetrical, and the anti-symmetrical internal force on the symmetrical surface is zero; under the action of anti-symmetrical load, the deformation is anti-symmetrical, the bending moment diagram and the axial force diagram are anti-symmetrical, and the shear force diagram is symmetrical; the tower generally has symmetrical 6 legs or 8 legs support, as shown in Figure 1 , under the action of eccentric load, wind load and the like, one side is in tension and the other side is in compression, which is similar to the state of two legs subjected to lateral force, and the 8-leg tower affected by eccentric load, wind load and the like is simplified into a two-leg structure subjected to lateral force, as shown in Figure 2 ; wherein Figure 1 , the symmetrical structure of the 6-leg tower under the action of wind load has three redundant constraint forces, which is a third-order statically indeterminate structure, that is, the number of unknown reaction forces is more than the static equilibrium equation by 3, and it is difficult to solve directly; since the wind load does not have symmetry, the wind load is divided into symmetrical load and anti-symmetrical load, as shown in Figure 3 ;

[0094] Figure 4 , the force condition of the simplified 8-leg symmetrical structure under the action of symmetrical wind load, at this time the symmetrical structure has two redundant unknown forces, and the anti-symmetrical internal force on the symmetrical surface is zero; Figure 5 , the force condition of the simplified 8-leg symmetrical structure under the action of anti-symmetrical wind load, at this time the symmetrical structure has one redundant unknown force, and the symmetrical internal force on the symmetrical surface is zero; for calculating the leg reaction force of the 8-leg tower, only the case of the tower subjected to anti-symmetrical wind load is considered; for simplifying the calculation, the left half of the original structure is studied, as shown in Figure 6 and Figure 7 ; according to the symmetry theory, the shear force and bending moment on the symmetrical axis cross section are zero, the simplified structure is a first-order statically indeterminate structure, the original third-order statically indeterminate structure is simplified into a first-order statically indeterminate structure, which only contains one redundant unknown force, greatly reducing the complexity of solving;

[0095] Under the action of anti-symmetrical wind load, the leg reaction force at the symmetrical position presents a strict anti-symmetrical relationship;

[0096] In this application, the windward leg includes leg 1-leg 4; the leeward leg includes leg 5-leg 8;

[0097] The size of the reaction force of the legs is equal according to the vertical symmetry of the silo center relative to the wind direction, that is = , = , = , = , the absolute value of the size of the reaction force of the four symmetrical legs is equal, the signs are opposite, and the size of the reaction force is proportional to the distance from the leg to the vertical symmetry plane of the silo center relative to the wind direction; the farther the distance, the greater the absolute value of the reaction force of the leg; this law reduces the calculation amount by half, and only the reaction force of the unilateral leg needs to be solved, and the reaction force of the other side can be derived through symmetry.

[0098] S3: Superimpose each leg static support force and dynamic support force to obtain the estimated support force of each leg; filter calculation is performed on the estimated support force of each leg under wind load and the real-time measured support force of each leg to obtain accurate wind load dynamic total support force; the accurate wind load dynamic total support force minus the static support force of each leg to obtain accurate total wind load dynamic support force of the silo;

[0099] S4: The actual accurate weight of the feed is obtained by deducting the accurate wind load dynamic support force and the self-weight of the silo from the total weight of the silo and the feed.

[0100] In step S1, the self-weight of the silo, the total weight of the silo and the feed, and the static support force of each leg of the silo are determined, specifically:

[0101] According to the force sensor arranged at the bottom of each leg of the silo, in a windless environment, ensure that the silo is placed horizontally, and the bottom of the leg is not loose or suspended; if the silo is empty, record the self-weight G 塔体 of the silo; and measure the diameter of the silo, the height of the silo;

[0102] Add a known weight of feed G 饲料总重 to the silo, and record the total weight G 总 of the silo and the feed;

[0103] According to the force sensor arranged at the bottom of each leg of the silo, collect the reaction force data of all legs under no wind load, take the average value of 10 continuous samples, and obtain the static support force of each leg ; calculate the algebraic sum of the reaction force of all legs ; ; calculate , and verify that the deviation from G 总 ×g (g is the acceleration of gravity, taken as 9.8 m / s 2 ) is ≤0.1%, to ensure the accuracy of the reaction force measurement under no wind load;

[0104] In step S2, the wind direction is measured and the legs of the stock tower are divided into windward group and leeward group according to the wind direction; all the legs are fitted into two or more symmetrical virtual leg structures along the wind direction, and a dynamic support force distribution model of the virtual legs of the stock tower under wind load is established, which is specifically:

[0105] A wind speed sensor and a wind direction sensor are installed near the stock tower to collect wind speed v and wind direction in real time; wind load force F W and overturning moment M are calculated according to the wind speed v;

[0106] According to the structure drawing of the stock tower and the wind direction, the legs are divided into windward group on the windward side and leeward group on the leeward side according to the vertical symmetry plane passing through the center of the stock tower perpendicular to the wind direction; the legs are sequentially numbered as the first to the nth;

[0107] The vertical distance of each leg to the vertical symmetry plane of the center of the stock tower perpendicular to the wind direction is measured; the vertical distances of the windward legs and the leeward legs are ensured to be one-to-one corresponding;

[0108] The distance from the first windward leg 1 of the first group to the center axis is , and the distance from the first leeward leg n+1 of the first group to the center axis is also ; in this application, the eight legs are divided into four groups, and the vertical distances of the four groups of legs to the center axis are respectively =1.024m, =0.8m, =0.6m, =0.5m;

[0109] A wind speed sensor and a wind direction sensor are installed near the stock tower to collect wind speed v and wind direction in real time; the measurement range of the wind speed sensor is 0-30m / s, the accuracy is ±0.1m / s, and wind speed v and wind direction are collected in real time; the wind direction is collected to ensure that the wind direction is perpendicular to the symmetry plane of the stock tower, if the wind direction deviates, the wind load coefficient needs to be corrected; wind load force and overturning moment M are calculated according to the wind speed v; =0.5×O×C×S; wherein O is air density, the air density in this application is taken as 1.225kg / m 3 , the wind resistance coefficient is taken as 1.3 for the steel structure of the stock tower; S is the windward area of the stock tower taken as 8.5m 2 ; M= × ;

[0110] A mathematical model of the dynamic support force of the stock tower under wind load is established according to the symmetry theory, and the dynamic support force of each leg caused by wind load is calculated;

[0111] Specifically, wind speed sensor and wind direction sensor are installed near the tower, real-time collection of wind speed v and wind direction; according to the wind speed v to calculate the wind load ;

[0112] According to the tower structure drawing and wind direction, set the north direction as the initial zero position of the wind direction sensor, and set the Y axis positive direction on the horizontal plane. Set the positive east direction perpendicular to the Y axis on the horizontal plane as the X axis positive direction. Further, divide the horizontal plane into four quadrants according to the conventional plan. At the same time, determine the leg number, as follows: facing north, start numbering counterclockwise, and record as the first to the nth, according to the installation position to determine the initial angle of each leg to the north direction. Further, determine the vertical symmetry plane passing through the tower center perpendicular to the wind direction as the neutral symmetry plane, which divides the legs into the windward group on the windward side and the leeward group on the leeward side; further determine the leg number falling into the windward group and the leeward group;

[0113] Determine the vertical distance of each leg to the vertical symmetry plane of the tower center perpendicular to the wind direction of the tower. The method is as follows: first, determine the projection of each leg position on the horizontal plane. The connecting line between the projection point and the projection of the tower center on the horizontal plane is equal to the angle between the tower radius R and the Y axis (angle value 0~180°), further determine the angle β between the neutral symmetry plane and the north direction (angle value 0~90°).

[0114] Secondly, when the northeast wind acts on the tower, the neutral plane is located in the second and fourth quadrants, the distance between the legs of the leeward group and the neutral plane =Rsin( ), the distance between the legs of the windward group and the neutral plane =Rsin( ), when the southwest wind, the distance between the legs of the windward group and the neutral plane =Rsin( ), the distance between the legs of the leeward group and the neutral plane =Rsin( ).

[0115] When the southeast wind acts on the tower, the neutral plane is located in the first and third quadrants, the distance between the legs of the windward group and the neutral plane =Rsin( ), the distance between the legs of the windward group and the neutral plane =Rsin( ), when the northwest wind, the distance between the legs of the leeward group and the neutral plane =Rsin( ), the distance between the legs of the windward group and the neutral plane =Rsin( );

[0116] The calculation model method of the dynamic support force of the virtual leg of the stock tower under the wind load condition is as follows, specifically:

[0117] The wind direction is measured, and the stock tower legs are divided into windward groups and leeward groups according to the wind direction; according to the symmetry of the arrangement of the stock tower legs, all the legs are fitted into two virtual leg structures symmetrical to the symmetric neutral plane, including windward virtual legs and leeward virtual legs; the stock tower legs are simplified into a statically indeterminate structure, and the redundant constraint reaction force The deformation coordination equation is established as an unknown quantity:

[0118]

[0119] Wherein, is the unit redundant unknown constraint reaction force =1 acting alone on the basic structure, the displacement caused along ; is the displacement along direction when the wind load acts alone;

[0120] The deformation coordination equation is solved to obtain , and the static equilibrium equation is combined to obtain the leg dynamic support force of the windward group and the windward group ; wherein, according to the symmetry theory: = ; in this application, =2.047m;

[0121] The deformation coordination equation is specifically:

[0122]

[0123] Wherein, is the diameter of the stock tower, is the height of the stock tower, is the wind load;

[0124] The static equilibrium equation is combined to obtain the leg dynamic support force and of the windward group and the windward group, specifically:

[0125] The force method regular equation can be solved to obtain the support constraint reaction force , and the equation can be obtained according to the static equilibrium principle:

[0126] + =0;

[0127] The leeward virtual leg is forced along the leg direction due to the wind load:

[0128] ;

[0129] The virtual supporting legs of the windward group are subjected to force due to wind load in the leg direction:

[0130]

[0131] According to the above formula, the constraint reaction force of the support can be calculated as and ; then, the vertical symmetry plane of each leg to the center of the tower perpendicular to the wind direction is set as , , … … According to the vertical distance of the leg of the tower to the neutral plane of the tower , the dynamic supporting force of the windward group leg is distributed to the n legs as , wherein =1~n; then, the dynamic supporting force of the windward group leg is The formula is:

[0132]

[0133] The dynamic supporting force of the windward group leg is The formula is:

[0134]

[0135] In step S3, the estimated supporting force of each leg is obtained by superimposing the static supporting force and the dynamic supporting force of each leg, which is specifically:

[0136] The estimated supporting force of the leg .

[0137] In step S3, the precise dynamic supporting force of the wind load is calculated by filtering the estimated supporting force of each leg under the wind load and the real-time measured leg supporting force of each leg, which is specifically:

[0138] The real-time supporting force of the windward leg is obtained by the pressure sensor installed at the bottom of each leg of the tower .

[0139] The precise dynamic supporting force of the wind load is calculated by Kalman filtering, and the specific operation is as follows:

[0140] The prior estimation formula is constructed as:

[0141]

[0142] wherein, is the state transition matrix from to . ​​​​

[0143] is the control matrix from time to time ;

[0144] is the Gaussian white measurement noise vector;

[0145] is the state parameter vector at time ; is composed of

[0146] The formula of the prior error covariance matrix is constructed as :

[0147] ;

[0148] wherein Q is the error covariance matrix of the system process noise;

[0149] The operation formula of the Kalman filter gain is as follows :

[0150] ;

[0151] wherein is the observation matrix of the object, is the covariance error matrix of the noise in the measurement data;

[0152] The formula of the Kalman gain is calculated as

[0153] ;

[0154] wherein is the observation matrix; Specifically, the measurement value of each leg force sensor is composed of ;

[0155] The posteriori covariance matrix required for the next filtering iteration is calculated according to the formula by combining the Kalman gain, the prior covariance and the observation matrix:

[0156] ;

[0157] This matrix will be used as the initial value of the prior covariance of the next filtering, ensuring the recursion and continuity of the filtering process;

[0158] The optimal estimation of the last filtering iteration time (i.e. time ) is used as the prior estimation to predict the current (i.e. time The state of each leg is predicted at the current time, and then the predicted value is corrected by the real-time measured leg support force to obtain an optimal estimation; iteration finally obtains the accurate total support force of each leg under the wind load condition , and further, the dynamic support force of each leg caused by the wind load ; is obtained as the static support force of each leg;

[0159] The algebraic sum of all leg reaction forces is calculated: ;

[0160] The total dynamic support force caused by the wind load is calculated: ;

[0161] The net weight of the feed in the tower is calculated: .

[0162] Finally, the accurate wind load dynamic support force and the self-weight of the tower are deducted from the total weight of the tower and the feed to obtain the actual accurate weight of the feed.

[0163] The above is only the preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to obtain equivalent embodiments applied to other fields. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution of the present application, and in accordance with the technical essence of the present application, still belong to the protection scope of the technical solution of the present application.

Claims

1. A high-precision calculation method for weighing a feed tower of a farm under wind load conditions, comprising a feed tower, wherein the feed tower adopts an even multiple of a leg structure; the number of legs is n, and n = 6 or 8, characterized in that, The specific steps are as follows: S1: Determine the self weight of the silo, the total weight of the silo and the feed, and the static support force of each leg of the silo under no wind load; S2: Measure the wind direction and divide the silo legs into windward group and leeward group according to the wind direction; fit all the legs into two or more symmetrical virtual leg structures along the wind direction; and establish a virtual leg dynamic support force distribution model of the silo under wind load to obtain the dynamic support force of each leg; Wherein, the virtual leg dynamic support force distribution model of the silo under wind load is established to obtain the dynamic support force of each leg, specifically: measure the wind direction and divide the silo legs into windward group and leeward group according to the wind direction; according to the symmetry of the silo leg arrangement, all the legs are fitted into two virtual leg structures symmetrical to the symmetric neutral plane, including windward virtual leg and leeward virtual leg; simplify the silo legs into a statically indeterminate structure to obtain the dynamic support force of each leg; S3: Superimpose the static support force and the dynamic support force of each leg to obtain the estimated support force of each leg; use the estimated support force of each leg under wind load and the real-time measured leg support force of each leg to perform filtering calculation to obtain the accurate wind load dynamic total support force; subtract the static support force of each leg from the accurate wind load dynamic total support force to obtain the accurate total wind load dynamic support force of the silo; S4: Subtract the accurate wind load dynamic support force and the self weight of the silo from the total weight of the silo and the feed to obtain the actual accurate weight of the feed; In step S2, the wind direction is measured and the silo legs are divided into windward group and leeward group according to the wind direction; all the legs are fitted into two or more symmetrical virtual leg structures along the wind direction, and a virtual leg dynamic support force distribution model of the silo under wind load is established, specifically: Wind speed sensor and wind direction sensor are installed near the material tower to collect wind speed v and wind direction in real time; wind load force is calculated according to wind speed v and overturning moment M; According to the silo structure drawing and the wind direction, the legs are divided into windward group on the windward side and leeward group on the leeward side according to the vertical symmetry plane passing through the center of the silo perpendicular to the wind direction; the legs are sequentially numbered as the first to the nth; Measure the vertical distance of each leg to the vertical symmetry plane of the silo center perpendicular to the wind direction; ensure that the vertical distances of the windward legs and the leeward legs are one-to-one corresponding; Measure the vertical distance of each leg to the vertical symmetry plane of the silo center perpendicular to the wind direction; ensure that the vertical distances of the windward legs and the leeward legs are one-to-one corresponding, specifically: The vertical distance of each leg to the vertical symmetry plane of the material tower center perpendicular to the wind direction is determined as follows: first, the projection of each leg position on the horizontal plane is determined, and the connecting line between the projection point and the projection of the material tower center on the horizontal plane is equal to the included angle between the material tower radius R and the Y axis , The included angle is 0-180°, and the included angle β between the neutral symmetry plane and the north direction is further determined, and the included angle β is 0-90°. Secondly, when the northeast wind acts on the tower, the neutral plane is located in the second and fourth quadrants, the distance between the leg of the leeward group and the neutral plane =Rsin( ), the distance between the leg of the windward group and the neutral plane =Rsin( ), when the southwest wind, the distance between the leg of the windward group and the neutral plane =Rsin( ), the distance between the leg of the leeward group and the neutral plane =Rsin( ); When the southeast wind acts on the tower, the neutral plane is located in a three quadrant, the distance between the leg of the windward group and the neutral plane = R sin ( ), the distance between the leg of the windward group and the neutral plane = R sin ( ), when the northwest wind, the distance between the leg of the leeward group and the neutral plane = R sin ( ), the distance between the leg of the windward group and the neutral plane = R sin ( ).

2. The high-precision calculation method for the feed tower weight of a farm under wind load conditions according to claim 1, characterized in that, In step S1, the self weight of the silo, the total weight of the silo and the feed, and the static support force of each leg of the silo under no wind load are determined, specifically: According to the force sensor arranged at the bottom of each leg of the tower, the tower is ensured to be placed horizontally without looseness or suspension at the bottom of the leg in a windless environment; if the tower is an empty tower, the self-weight G of the tower is recorded 塔体 ; and the diameter of the tower , the height of the tower are measured; According to the force sensor arranged at the bottom of each leg of the stock tower, the reaction force data of all legs under no wind load are collected, the average value is obtained by continuous sampling for 10 times, and the static support force of each leg is obtained ; calculating the total leg reaction force algebraic sum ; .

3. The high-precision calculation method for the feed tower weight of a farm under wind load conditions according to claim 1, characterized in that, According to the silo structure drawing and the wind direction, the legs are divided into windward group on the windward side and leeward group on the leeward side according to the vertical symmetry plane passing through the center of the silo perpendicular to the wind direction; the legs are sequentially numbered as the first to the nth, specifically: According to the material tower structure drawing and the wind direction, the north direction is set as the initial zero position of the wind direction sensor, and is set as the Y-axis positive direction on the horizontal plane. The positive east direction perpendicular to the Y-axis on the horizontal plane is set as the X-axis positive direction. Further, the horizontal plane is divided into four quadrants according to the conventional plan. Meanwhile, the leg numbers are determined, which are numbered from 1 to n in the anticlockwise direction from the north direction. The initial angle between each leg and the north direction is determined according to the installation position. The vertical symmetry plane passing through the center of the material tower and perpendicular to the wind direction is determined as the neutral symmetry plane, which divides the legs into the windward group on the windward side and the leeward group on the leeward side. Further, the leg numbers falling into the windward group and the leeward group are determined.

4. The high-precision calculation method for the feed tower weight of a farm under wind load conditions according to claim 1, characterized in that, The material tower leg is simplified as a statically indeterminate structure to obtain the dynamic support force of each leg, which is specifically: After the static indeterminate structure is analyzed by force method, the redundant constraint reaction is changed into support reaction, and the support reaction is taken as the unknown quantity to establish deformation compatibility equation As the unknown quantity, the deformation compatibility equation is established wherein, is the unit redundant unknown constraint reaction force =1 acting alone on the basic structure, the displacement along ; direction caused by is the displacement along direction caused by the wind load acting alone The deformation compatibility equation is solved to obtain , and the dynamic support force of the upwind group and the support leg of the upwind group is obtained by combining the static equilibrium equation .

5. The high-precision calculation method for the feed tower weight of a farm under wind load conditions according to claim 4, characterized in that, The dynamic support force of the upwind group and the downwind group is obtained by combining the static equilibrium equation and , specifically: The force method regular equation can be solved to obtain the support constraint reaction force According to the static equilibrium principle, the equation can be obtained: + =0； The virtual leg of the leeward group is stressed in the leg direction due to wind load: ； The virtual leg of the windward group is stressed in the leg direction due to wind load: ； According to the above formula, the support constraint reaction force can be calculated and ; then, the vertical symmetry planes of each leg to the center of the tower perpendicular to the wind direction are sequentially set as 、 、 … … , according to the vertical distance of the tower leg to the neutral plane of the tower , the dynamic support force of the n legs of the leeward group is allocated , wherein =1~n; at this time, the dynamic support force of the leeward group leg is The formula is: ； The dynamic support force of the windward group outrigger is The formula is: 。 6. The high-precision calculation method for the feed tower weight of a farm under wind load conditions according to claim 5, characterized in that, In step S3, the estimated support force of each leg is obtained by superimposing the static support force and the dynamic support force of each leg, which is specifically: Estimated support force of a leg .

7. The high-precision calculation method for the feed tower weight of a farm under wind load conditions according to claim 1, characterized in that, In step S3, the precise wind load dynamic support force is obtained by filtering calculation using the estimated support force of each leg under wind load and the real-time measured leg support force of each leg, which is specifically: Real-time support force of the windward leg is obtained by a pressure sensor installed at the bottom of each leg of the tower ; The precise wind load dynamic support force is calculated by Kalman filtering, and the specific operation is as follows: The prior estimation formula is constructed: ； wherein is the state transition matrix at time the state transition matrix at time for controlling the matrix from time to time; is the Gaussian white measurement noise vector; For the state parameter vector at time instant t: the vector consisting of Constructing a priori error covariance matrix formula : ； wherein Q R is the error covariance matrix for the system process noise; wherein the operation formula of the Kalman filter gain is as follows : ； wherein, is an observation matrix for the object, is a covariance error matrix for the noise in the measurement data; The Kalman gain calculation formula is constructed: ； wherein is an observation matrix; is the measured value of each leg force sensor consisting of; According to the formula, the posterior covariance matrix required for the next filtering iteration is calculated by combining the Kalman gain, the prior covariance and the observation matrix: The optimal estimation of the iteration moment of the above once filtering is taken as the prior estimation to predict the current state, and then the real-time measured supporting force is used to correct the predicted value to obtain the optimal estimation; and the precise total supporting force of each supporting leg under the wind load condition is finally obtained through iteration , and further, the dynamic supporting force of each supporting leg caused by the wind load can be obtained ; is the static supporting force of each supporting leg Compute total leg reaction algebraic sum: ; Calculate the dynamic support forces caused by the total wind load: ; Calculate the net weight of the feed in the silo: .

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