System for measuring grain flow and harvester

Abstract

The invention discloses a system for measuring grain flow and a harvester. The grain flow is the flow of net grain passing through the spiral conveyor, a driving shaft for driving the spiral conveyor to rotate and the spiral conveyor are arranged in a decoupling mode, and the system comprises a first measuring module configured to measure stress data of the spiral conveyor; the second measuring module is configured to measure rotating speed data of the spiral conveyor; and the overall planning module is configured to determine the grain flow based on the stress data, the rotating speed data and the attributes of the spiral conveyor, and the attributes of the spiral conveyor comprise the net weight of the spiral conveyor, the conveying length of the spiral conveyor and the screw pitch of the spiral conveyor. According to the system, the measurement precision of the grain flow can be improved, and meanwhile the cost is considered.

Description

Technical Field

[0001] The present application relates to the technical field of grain flow measurement, and in particular to a system and a harvester for measuring grain flow. Background Art

[0002] A combine harvester is an agricultural machinery that integrates the functions of harvesting, threshing, cleaning, and loading grain, and plays an important role in modern agricultural production. In order to further improve the operating efficiency and intelligence level, the prior art proposes a method of setting sensors in a combine harvester to measure grain flow in real time. These sensors include, for example, photoelectric sensors, impulse sensors, volumetric sensors, and gamma-ray sensors. By processing the data from the sensors, dynamic monitoring of grain flow can be achieved, providing support for precision agricultural management.

[0003] However, the existing grain flow measurement methods still face some technical bottlenecks in practical applications. Due to factors such as unreasonable sensor layout, mechanical structure interference and environmental changes, the measurement accuracy of the existing methods is difficult to meet high-precision requirements. In addition, the complex sensor installation and calibration process increases the overall cost of the system, which limits its promotion and application.

[0004] Therefore, how to improve the measurement accuracy of grain flow while taking into account the cost is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the present application discloses a system and a harvester for measuring grain flow, which improves the measurement accuracy of grain flow while taking cost into consideration.

[0006] In the first aspect, the present application discloses a system for measuring grain flow, wherein the grain flow is the flow of clean grain passing through a screw conveyor, wherein a drive shaft driving the screw conveyor to rotate is decoupled from the screw conveyor, and the system comprises: a first measuring module configured to measure force data of the screw conveyor; a second measuring module configured to measure rotational speed data of the screw conveyor; and a coordination module configured to determine the grain flow based on the force data, rotational speed data and properties of the screw conveyor, wherein the properties of the screw conveyor include the net weight of the screw conveyor, the conveying length of the screw conveyor and the pitch of the screw conveyor.

[0007] Optionally, a gear sleeve is arranged between the drive shaft and the screw conveyor, the first end of the gear sleeve is slidingly connected to the intermediate shaft of the screw conveyor, and the second end of the gear sleeve is connected to the drive shaft, so that the drive shaft drives the intermediate shaft of the screw conveyor to rotate; the gear sleeve has an internal space, and the internal space is arranged between the inner wall of the gear sleeve, the drive shaft and the intermediate shaft of the screw conveyor, so that the drive shaft and the screw conveyor are decoupled in the axial force direction.

[0008] Optionally, the first end of the gear sliding sleeve is also fixed to the housing of the screw conveyor through a support member. The gear sliding sleeve is connected to the support member through a bearing. The inner ring of the bearing is fixed to the first end of the gear sliding sleeve, and the outer ring of the bearing is fixed to the support member. Adjusting bolts are respectively arranged at the first end and the second end of the support member for fixing the support member and the housing of the screw conveyor.

[0009] Optionally, clamping nuts are respectively arranged on both sides of each adjusting bolt relative to the support member for adjusting the distance between the gear sliding sleeve and the screw conveyor.

[0010] Optionally, the system for measuring the grain flow rate further includes a third measurement module disposed on the carrier where the screw conveyor is located and configured to measure the acceleration data in the direction perpendicular to the carrier.

[0011] Optionally, the first measurement module includes at least one load cell. The at least one load cell is used to support the screw conveyor and measure the force data in the vertical direction of the screw conveyor and the clean grain located inside the screw conveyor; alternatively, the first measurement module includes a tension sensor. The tension sensor is disposed on the side of the screw conveyor away from the drive shaft for measuring the force data in the vertical direction of the screw conveyor and the clean grain located inside the screw conveyor.

[0012] Optionally, the calculation formula for the grain flow rate includes:

[0013]

[0014] m g =m S -m 0 ;

[0015]

[0016] where, F c represents the data of each load cell, C represents the number of load cells, G represents the sum of the data of each load cell, a represents the acceleration data, m S represents the mass of the screw conveyor and the clean grain located inside the screw conveyor, m 0 represents the net weight of the screw conveyor, m g represents the mass of the clean grain inside the screw conveyor, L represents the conveying length of the screw conveyor, p represents the pitch of the screw conveyor, n represents the rotational speed data, t represents the time for the clean grain to pass through the screw conveyor, and Q represents the grain flow rate.

[0017] Optionally, the calculation formula for the grain flow rate further includes:

[0018]

[0019] Among them, t M represents each sampling cycle, N represents the number of revolutions of the screw conveyor in each cycle, Q i represents the grain flow in the ith cycle, m gi represents the mass of clean grain in the i-th sampling period; and when (N 1 +N 2 +…+N i )p>L, the parameters in the above calculation formula and The corresponding relationship is as follows:

[0020]

[0021] Based on the above calculation formula, the following set of equations can be obtained by combining i measurements and sampling:

[0022]

[0023] The above equations are solved through the initialization process to obtain the grain flow rate at the corresponding time.

[0024] Optionally, the calculation process of the grain flow rate includes a calibration correction process, and the calibration correction process includes the following calculation formula:

[0025]

[0026] Q c =KQ r ;

[0027] Among them, m 1 represents the mass of the screw conveyor and the clean grain inside the screw conveyor, K represents the linear comprehensive error coefficient, Q r represents the grain flow rate before correction, Q c represents the corrected grain flow rate.

[0028] In a second aspect, the present application discloses a harvester, comprising the system for measuring grain flow as disclosed in the first aspect above.

[0029] In summary, the system and harvester for measuring grain flow disclosed in the present application have at least the following beneficial effects:

[0030] (1) By achieving decoupling between the drive shaft and the screw conveyor, the weight of the screw conveyor is completely borne by the contact point with the harvester, which can avoid the weight of the drive shaft affecting the measurement results of the weighing sensor and improve the measurement accuracy.

[0031] (2) By measuring the force data, rotation speed data, and acceleration data respectively, the errors caused by the bumps of the harvester can be effectively corrected, thereby improving the measurement accuracy. In other words, regardless of whether the screw conveyor is perpendicular to the ground or has a certain angle with the ground, the system can achieve accurate measurement.

[0032] (3) The system disclosed in the present application is directly applied on the basis of the structure of the harvester, which reduces the additional cost and has better adaptability. In addition, the grain flow in the present application is the flow of net grain (that is, the flow does not include straw), which can more accurately reflect the actual working efficiency of the harvester and achieve accurate yield estimation, providing reliable data support for agricultural decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following is a brief introduction to the drawings used in describing the embodiments of this application:

[0034] Figure 1 This is a structural example diagram of a system for measuring grain flow provided in an embodiment of the present application.

[0035] Figure 2 This is a structural example diagram of a screw conveyor and related components provided in an embodiment of the present application.

[0036] Figure 3 This is a structural example diagram of a gear sleeve provided in an embodiment of the present application.

[0037] In the figure: bearing-110, screw conveying auger-120, weighing sensor-130, speed gear-140, speed sensor-150, gear sleeve-160, tension sensor-170, guide shaft-180, adjusting bolt-190, support-200, base-210, clamping nut-220, fixed body structure-230, screw conveying cavity-240, scraper-250. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other accompanying drawings and other implementation methods can be obtained based on these drawings without creative work. Adjustments and improvements made without departing from the concept of the present application are all within the scope of protection of the present application.

[0039] To simplify the drawings, only the parts related to the corresponding embodiments are schematically shown in each drawing, and they do not represent the actual structure of the product. In addition, to simplify the drawings for easy understanding, in some drawings, only some of the components with the same structure or function are schematically shown, and there may actually be more or fewer components with the same structure or function.

[0040] In this application, unless otherwise clearly specified and defined, ordinal numbers, such as "first", "second", etc., are only used to distinguish and describe related objects, and cannot be understood as indicating or implying the relative importance or order between related objects; in addition, they do not represent the quantity of related objects. "Multiple" includes two or more, and other quantifiers are similar. " / " is used to describe the relationship between related objects, which represents the "or" relationship between related objects. "And / or" is used to describe the relationship between related objects, which includes any combination relationship between related objects. For example, "a and / or b" includes: "a alone", "b alone", or "a and b". "One or more" or "at least one" of multiple objects refers to any object or any combination of multiple objects. For example, "one or more of a1, a2, a3" or "at least one of a1, a2, a3" includes: "a1 alone", "a2 alone", "a3 alone", "a1 and a2", "a1 and a3", "a2 and a3", or "a1, a2 and a3".

[0041] During the harvesting operation of a combine harvester, the harvested grains are transported to the grain tank through structures such as a spiral grain conveyor or a scraper elevator, and the unloading operation is carried out when the grain tank is full. By establishing a corresponding grain yield measurement system for the combine harvester, the yield information of the grains during this operation process is obtained, the real-time detection of the grain flow is realized, and by generating a corresponding yield distribution map, it is used to evaluate the quality of the harvesting operation and guide the precise operation of each link of plowing, sowing, managing, and harvesting of the next season's crops. At present, the grain flow sensors used in combine harvesters mainly include photoelectric sensors, volumetric sensors, gamma-ray sensors, impulse sensors, etc. Among them, impulse sensors and photoelectric flow sensors are widely used due to their simple structure and low cost.

[0042] The photoelectric sensor is mainly used for the scraper elevator. By measuring the height of the grain pile on each scraper passing through the sensor, the volume of the grain pile is estimated, and then the grain flow is estimated. Since this method estimates the volume through the height of the grain pile, it is affected by the randomness of the grain pile shape, and the calculation error is relatively large. To estimate the weight through the volume, it is necessary to know the bulk density of the harvested grains in advance. Therefore, when harvesting different types, varieties, or even different maturities of crops, it is necessary to recalibrate the bulk density to obtain a more accurate weight value.

[0043] The impulse sensor measures the grain flow by measuring the impact force of the grain on the impulse plate at the grain outlet of the elevator. The core calculation formula is Ft = mv. Since the impact force F, time t, and velocity v in the formula can all be measured, the impact mass m can be calculated. This principle has derived double-plate and suspended-plate measurement methods to optimize the impact of vibration on the measurement results. Since not all grains will impact on the impulse plate in this method, it is essentially a partial sampling measurement method, and the results need to be calibrated. In addition, the commercialized solutions on the market are rigidly connected to the harvester at present, resulting in a greater impact of vibration on the measurement results.

[0044] The volumetric sensor generally calculates the weight of the grain in the granary by measuring the accumulated volume of the grain in the granary through vision or radar, and calculates the grain flow by calculating the weight difference between two moments. Since the volumetric method can only measure the shape of the accumulation surface, it is necessary to perform a three-dimensional modeling of the entire granary in advance, which will cause difficulties for subsequent calculations for complex granary structures. On the other hand, the volumetric measurement method calculates the flow rate through the total weight difference at different times. If the time interval is selected to be short, the error will be large; if the time interval is selected to be large, the difference in output cannot be reflected.

[0045] The γ-ray sensor measures the grain flow by placing a radiation source and a Geiger counter for opposed measurement at the grain outlet of the elevator. When the grain passes through, the intensity of the γ-ray decreases, so as to calculate the grain flow. Since it is relatively difficult to obtain and manage the radiation source, this method is rarely used in the civilian field and is generally used for real-time flow measurement of minerals.

[0046] It can be seen from this that the accuracy of the methods for measuring grain flow by sensors in the prior art needs to be improved, and the complex sensor installation and calibration processes increase the overall cost of the system, restricting the popularization and application. Therefore, the core concept of this application is to improve the measurement accuracy by implementing a decoupling method, and to reduce the cost by reasonably configuring various sensors.

[0047] The following will be described with reference to the accompanying drawings.

[0048] Figure 1 It is a structural example diagram of a system for measuring grain flow provided by an embodiment of this application. Please refer to Figure 1 , the system for measuring grain flow includes: a first measurement module 10 configured to measure the force data of the screw conveyor; a second measurement module 20 configured to measure the rotational speed data of the screw conveyor; and a coordination module 30 configured to determine the grain flow based on the force data, rotational speed data, and the attributes of the screw conveyor, where the attributes of the screw conveyor include the net weight of the screw conveyor, the conveying length of the screw conveyor, and the pitch of the screw conveyor.

[0049] In this application, the grain flow rate is the flow rate of clean grain passing through the screw conveyor, and the drive shaft that drives the screw conveyor to rotate is arranged in a decoupled manner with the screw conveyor. By measuring the clean grain flow rate, the interference of impurities such as straw is avoided, and the actual working efficiency of the harvester can be more accurately reflected. Moreover, clean grain is the main target of the final harvest. Directly measuring the clean grain flow rate can more accurately estimate the field crop yield and provide reliable data support for agricultural decision-making. In addition, if the straw flow rate is included, it may be necessary to perform secondary separation and calibration of the data through algorithms, increasing the system complexity. Directly measuring the clean grain flow rate can simplify the measurement model and subsequent processing.

[0050] The first measurement module 10 is configured to measure the force data of the screw conveyor. Its setting method can be to be arranged at the bottom of the screw conveyor (measuring pressure), or to be arranged at the top of the screw conveyor (measuring tension). When the first measurement module 10 is arranged at the bottom of the screw conveyor, the first measurement module 10 includes at least one load cell; when the first measurement module 10 is arranged at the top of the screw conveyor, the first measurement module 10 includes a tension sensor. Different setting methods correspond to different usage scenarios. For example, when the working environment of the harvester is a relatively flat farmland, either a load cell can be used to measure the force data, or a tension sensor can be used to measure the force data. Another example is that when the working environment of the harvester is relatively rough and prone to jolts, or when the screw conveyor is placed obliquely, a load cell can be used to measure the force data, and each load cell supports the screw conveyor to improve the accuracy of the measured data.

[0051] In order to improve the accuracy of the force data obtained by the first measurement module 10, the drive shaft in this application is arranged in a decoupled manner with the screw conveyor, and this drive shaft is used to drive the screw conveyor to rotate. For example, when the screw conveyor is perpendicular to the ground, the first measurement module 10 includes 3 load cells, and each load cell is arranged at the bottom of the screw conveyor and the angle between each two is 120°, so as to improve the stability of the screw conveyor. The drive shaft is generally arranged at the bottom of the screw conveyor. By means of decoupling, the axial force between the drive shaft and the screw conveyor can be disconnected (that is, there is no force in the axial direction), so that the 3 load cells can obtain accurate force data of the screw conveyor. At this time, the force data of the screw conveyor is the sum of the net weight of the screw conveyor and the weight of the grain located inside the screw conveyor.

[0052] In some embodiments of this application, the first measurement module 10 further includes a signal conditioning circuit and an analog-to-digital converter. Since the measurement types of load cells and tension sensors are generally strain signals, and their signals are weak, usually a signal conditioning circuit is required to amplify the signals and then output them; and the output signals after signal conditioning are generally analog signals, so it is necessary to perform analog-to-digital conversion to obtain digital signals that can be accepted by the overall module 30.

[0053] In some embodiments of the present application, the second measurement module 20 includes a rotational speed sensor and a signal isolation circuit. Common types of rotational speed sensors are photoelectric proximity switches, magnetic field proximity switches, metal induction proximity switches, and rotary encoders, and their outputs are generally pulse signals. In order to obtain signals acceptable to the coordination module 30, the required pulse signals can usually be obtained through an isolation circuit.

[0054] The coordination module 30 determines the grain flow rate based on the above first measurement module 10, second measurement module 20, and the properties of the screw conveyor itself. The specific calculation method can refer to the subsequent embodiments.

[0055] In some embodiments of the present application, please continue to refer to Figure 1 , the system further includes a human-machine interaction module 50. The human-machine interaction module 50 is mainly used for data display, user settings, and data calibration. The setting of this module is mainly for the convenience of user operation and data browsing, and does not affect the underlying logic of measuring the grain flow rate.

[0056] Figure 2 is a structural schematic diagram of a screw conveyor and related components provided by an embodiment of the present application, Figure 3 is a structural schematic diagram of a gear sliding sleeve provided by an embodiment of the present application. Please refer to Figure 2 and Figure 3 , a gear sliding sleeve 160 is provided between the drive shaft and the screw conveyor. The first end of the gear sliding sleeve 160 is slidably connected to the intermediate shaft of the screw conveyor, and the second end of the gear sliding sleeve 160 is connected to the drive shaft so that the drive shaft drives the intermediate shaft of the screw conveyor to rotate; the gear sliding sleeve 160 has an internal space, and the internal space is arranged between the inner wall of the gear sliding sleeve 160, the drive shaft, and the intermediate shaft of the screw conveyor, so that the drive shaft and the screw conveyor are decoupled in the axial force direction. In some embodiments of the present application, the first end of the gear sliding sleeve 160 is also fixed to the housing of the screw conveyor through a support member 200. The gear sliding sleeve 160 is connected to the support member 200 through a bearing 110. The inner ring of the bearing 110 is fixed to the first end of the gear sliding sleeve 160, and the outer ring of the bearing 110 is fixed to the support member 200. Adjusting bolts 190 are respectively arranged at the first end and the second end of the support member 200 for fixing the support member 200 and the housing of the screw conveyor. Clamping nuts 220 are respectively arranged on both sides of each adjusting bolt 190 relative to the support member 200 for adjusting the distance between the gear sliding sleeve 160 and the screw conveyor. Among them, the intermediate shaft of the screw conveyor can also be called the screw conveyor auger 120. The decoupling process is essentially that the gear sliding sleeve 160 is lifted to disconnect the axial force between the drive shaft and the screw conveyor auger 120, thereby not affecting the weighing result.

[0057] Figure 2There are three example diagrams. In the left diagram, weighing is performed by a mass sensor installed at the bottom. In the middle diagram, weighing is performed by a sensor installed at the top. The screw conveyors in the left and middle diagrams are both perpendicular to the ground. There is a certain angle between the screw conveyor in the right diagram and the ground. Figure 3 The three example diagrams in it are all structural example diagrams of gear slip sleeves.

[0058] When the screw conveyor is vertically installed, the main force on the side wall is the clamping force, which is used for structural limitation. At this time, the weighing sensor 130 can be installed at the bottom of the screw conveyor, or the tension sensor 170 can be installed at the top of the screw conveyor. If the weighing sensor 130 is installed at the bottom of the screw conveyor, the number of weighing sensors 130 can be greater than or equal to 3, which is beneficial to structural stability. The upper and lower ends of the screw conveyor auger 120 and the screw conveyor cavity 240 are fixed and rotated by bearings 110. The bearings 110 can fix the rotating parts and non-rotating parts to each other to reduce vibration. The gear slip sleeve 160 is a key structure. If the drive shaft is directly connected to the screw conveyor auger 120, a part of the gravity of the screw conveyor will be loaded on the drive shaft, resulting in interference in the measurement results of the force data. The gear slip sleeve 160 can make the drive shaft only transmit radial force. The gear slip sleeve 160 pushes the support 200 to extend by adjusting the clamping nuts 220 on both sides, reserving the docking area with the drive shaft and docking the drive shaft. The radial force transmitted by the drive shaft is mainly used to overcome the rotational friction and provide the gravitational potential energy when lifting grains. The structure of the gear slip sleeve 160 is as Figure 3 shown. The entire structure is fixed by screwing the adjusting bolts 190 on both sides into the threaded posts below the screw conveyor cavity 240. The outer ring of the bearing 110 is fixed to the support 200 by interference fit, and the inner ring is fixed to the gear slip sleeve 160. Adjusting the clamping nut 220 drives the support 200 to push the gear slip sleeve 160 forward, and the gear slip sleeve 160 is docked with the drive shaft. The rotational speed sensor 150 is connected to the rotational speed gear 140 and is used to measure the rotational speed data of the screw conveyor. In Figure 2 the case of the middle diagram, it also includes a guide shaft 180 and a fixed vehicle body structure 230. The guide shaft 180 is connected to the fixed vehicle body structure 230 and is used to maintain the structural stability of the screw conveyor. Each weighing sensor 130 can be installed on the base 210. The scraper 250 is mainly used to assist in the conveying and cleaning of grains. For example, in some cases, relying solely on the rotation of the screw blades may not be able to completely drive the flow of some specific-shaped or -conditioned materials (such as wet grains, viscous materials). The scraper can help push these materials forward along the conveyor.

[0059] In some embodiments of the present application, please continue to refer to Figure 1, the system for measuring the grain flow further includes a third measurement module 40, which is disposed on the carrier where the screw conveyor is located and is configured to measure the acceleration data in the direction perpendicular to the carrier. Among them, the carrier where the screw conveyor is located can be a harvester. In some embodiments of the present application, the third measurement module 40 includes an acceleration sensor and a data conversion module. The acceleration sensor can be, for example, a microelectromechanical chip, and its output mode is usually I2C, SPI or UART. Therefore, a data conversion module is required to convert the data into a communication type convenient for transmission through a cable, such as RS485, RS232 or CAN. In addition, there are also some acceleration sensors that output in an analog signal manner, and the data conversion module can be replaced with an analog-to-digital converter so that the acceleration data can be effectively transmitted to the overall planning module 30. The acceleration sensor can be used to calibrate the weighing result in the vertical direction and reduce the error in the measurement process.

[0060] In some embodiments of the present application, the first measurement module includes at least one weighing sensor, and the at least one weighing sensor is used to support the screw conveyor and measure the force data of the screw conveyor and the clean grain located inside the screw conveyor in the vertical direction; alternatively, the first measurement module includes a tension sensor, and the tension sensor is disposed on the side of the screw conveyor away from the drive shaft and is used to measure the force data of the screw conveyor and the clean grain located inside the screw conveyor in the vertical direction.

[0061] In some embodiments of the present application, the calculation formula of the grain flow includes:

[0062]

[0063] m g =m S -m 0 ;

[0064]

[0065] Taking the weighing sensor as an example for illustration. Let the force data collected by each weighing sensor be F 1 ,F 2 ......F c ,C is the number of weighing sensors. In the direction perpendicular to the ground, in the formula, F c represents the data of each weighing sensor, and G represents the sum of the data of each weighing sensor, that is If it is a tension sensor, G represents the force data collected by the tension sensor. Let the axis perpendicular to the vehicle body upward of the acceleration sensor be the Z axis, and the acceleration data of the Z axis be a. Then the total mass of the screw conveyor after attitude calibration is m S ,m SRepresents the mass of the screw conveyor and the clean grain inside the screw conveyor, that is When the screw conveyor is horizontal with the ground, m S Satisfies the following formula: g is the acceleration due to gravity. m 0 Represents the net weight of the screw conveyor, then the mass m of the clean grain inside the screw conveyor during the actual harvesting process g Is m S And m 0 The difference of, that is m g = m S - m 0 . L represents the conveying length of the screw conveyor, p represents the pitch of the screw conveyor, n represents the rotational speed data, t represents the time for the clean grain to pass through the screw conveyor, that is the time experienced by the clean grain from the inlet to the outlet of the screw conveyor, that is Q represents the grain flow rate, that is Through the above calculation method, the grain flow rate can be determined by the force data, rotational speed data and the properties of the screw conveyor itself; and when the vehicle body is tilted, the grain flow rate can be further corrected by combining the acceleration data to improve the measurement accuracy.

[0066] The above formula is the measurement principle under ideal conditions. The values of t and m used in this formula g Are average values, and the obtained Q value is actually the average flow rate. In some embodiments of the present application, if the real-time flow rate and rotational speed are measured in each sampling period t M , and the number of rotations N of the screw shaft in each period, then the following formula can be further derived based on the above formula.

[0067]

[0068] In the formula, for And Do the following processing: when (N 1 + N 2 +…+ N i )p > L, the parameters in the above calculation formula And Have the following corresponding relationship:

[0069]

[0070] The purpose of the above process is to ensure that the measured grain quality corresponds one-to-one with the measurement time range.

[0071] Among them, t M Represents each sampling period, N represents the number of rotations of the screw conveyor in each period (the number of rotations is equal to the rotational speed multiplied by the time), Q iRepresents the grain flow rate within the i-th cycle, m gi Represents the mass of the net grain within the i-th sampling cycle.

[0072] Based on the above calculation formula, the following system of equations can be obtained by combining i measurements and samplings:

[0073]

[0074] Solve the above system of equations through the initialization process to obtain the grain flow rate at the corresponding moment.

[0075] When solving the above system of equations, the parameters Q and m in the first equation of the system of equations can be set to 0 through a preset initialization process. Specifically, after the screw conveyor starts, it will keep its interior free of grain and maintain this state for a period of time; this makes Q 1 to Q i all equal to 0. At this time, m gi is also 0, and all the quantities in the first equation are known quantities, then the initialization operation is completed. By combining the known quantities in the first equation with the second equation, there is only Q i+1 as an unknown quantity. By analogy, the flow rates at subdivided moments can be continuously calculated. In this way, after solving the above system of equations, the grain flow rate at the corresponding moment can be obtained.

[0076] Due to data error problems during the engineering process that can lead to error accumulation, the initialization can be continuously performed by taking advantage of the opportunities of turning around and pausing operations during the grain harvesting process, thereby reducing the error as much as possible.

[0077] In addition, the flow rate value within a shorter sampling period can be further obtained by increasing the sampling frequency and the resolution of the rotational speed sensor. Since the calculation process is a continuous process, the flow rate calculation results within each sampling period will be obtained i times. Therefore, after obtaining i groups of flow rates, methods such as the least squares method can also be used to obtain a grain flow rate closer to the true value.

[0078] In some embodiments of the present application, the values of the sensors can also be calibrated in advance to improve the measurement accuracy. For example, the proportional coefficient value of the tension sensor can be calibrated during installation or before leaving the factory to obtain a higher measurement accuracy. The vertical installation degree of the weighing sensor and the angular error during the chassis assembly are similar to the errors of the acceleration sensor and can be calibrated together. For the errors of the weighing sensor and the acceleration sensor in the pitch, roll, and yaw directions, the harvester can be made to pass through inclined planes with multiple known angles and remain stationary on the inclined planes during factory production, and the values of the sensors can be read. Through multiple sets of measurement data, an overdetermined system of equations can be established, and then data processing methods such as the least squares method can be used to solve the installation error angles.

[0079] In some embodiments of the present application, the calculation process of the grain flow includes a calibration and correction process, and the calibration and correction process includes the following calculation formula:

[0080]

[0081] Q c = KQ r ;

[0082] wherein, m 1 represents the mass of the screw conveyor and the clean grain located inside the screw conveyor, K represents the linear comprehensive error coefficient, Q r represents the grain flow before correction, and Q c represents the grain flow after correction.

[0083] According to the calculation formula in the above embodiments, since the main calculation processes are all linear processes, the linear comprehensive error coefficient K is introduced for correction.

[0084] Based on a similar technical concept, the present application discloses a harvester, including a system for measuring the grain flow as disclosed in the above embodiments. Exemplarily, the harvester can be a combine harvester. The combine harvester can operate independently, store the grain in its own granary, and then unload the grain when needed. For example, in small-scale operations, the combine harvester usually works independently and unloads the grain to a storage facility at a fixed location. In addition, in large-scale agricultural operations, in order to improve efficiency, the combine harvester can also work in cooperation with a grain transport vehicle. In this way, while harvesting and unloading the grain at the same time, the time for the harvester to stop and unload the grain can be reduced, which is especially suitable for large field plots with continuous operations. In different working scenarios, the setting of the screw conveyor can also be different. For example, when operating independently, the screw conveyor is usually placed vertically or nearly vertically to the ground, and is used to convey the grain from the cleaning system of the harvester to the grain tank. In this case, the main function of the screw conveyor is to lift the grain to a higher position for storage, and the structure is more suitable for vertical transmission. When operating in cooperation, the screw conveyor needs to be placed obliquely or adjusted in angle to convey the grain through the grain discharge port to the grain receiving vehicle. This oblique placement helps to achieve continuous and efficient grain transfer, reduce the operation interruption time, and improve the harvesting efficiency.

[0085] In the above embodiments, the descriptions of the respective embodiments have their own focuses. For parts not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. In addition, the above embodiments can be freely combined as needed.

Claims

1. A system for measuring grain flow, characterized in that The grain flow rate is the flow rate of clean grain passing through the screw conveyor, and the drive shaft driving the screw conveyor to rotate is arranged in a decoupled manner with the screw conveyor. The system includes: A first measuring module is configured to measure force data of the screw conveyor; A second measuring module is configured to measure the rotation speed data of the screw conveyor; The overall planning module is configured to determine the grain flow rate based on the force data, the rotation speed data and the properties of the screw conveyor, wherein the properties of the screw conveyor include the net weight of the screw conveyor, the conveying length of the screw conveyor and the pitch of the screw conveyor.

2. A system for measuring grain flow according to claim 1, characterized in that A gear sleeve is provided between the driving shaft and the screw conveyor, wherein a first end of the gear sleeve is slidably connected to an intermediate shaft of the screw conveyor, and a second end of the gear sleeve is connected to the driving shaft, so that the driving shaft drives the intermediate shaft of the screw conveyor to rotate; The gear sleeve has an internal space, and the internal space is arranged between the inner wall of the gear sleeve, the drive shaft and the intermediate shaft of the screw conveyor, so that the drive shaft and the screw conveyor are decoupled in the axial force direction.

3. A system for measuring grain flow according to claim 2, characterized in that The first end of the gear sleeve is also fixed to the outer shell of the screw conveyor through a support member, the gear sleeve is connected to the support member through a bearing, the inner ring of the bearing is fixed to the first end of the gear sleeve, the outer ring of the bearing is fixed to the support member, and the first end of the support member and the second end of the support member are respectively provided with adjusting bolts for fixing the support member and the outer shell of the screw conveyor.

4. A system for measuring grain flow according to claim 3, characterized in that Each of the adjusting bolts is provided with clamping nuts on both sides of the supporting member, respectively, for adjusting the distance between the gear sleeve and the screw conveyor.

5. The system for measuring grain flow according to claim 1, characterized in that It also includes a third measurement module, which is arranged on the carrier where the screw conveyor is located and is configured to measure acceleration data in a direction perpendicular to the carrier.

6. A system for measuring grain flow according to claim 5, characterized in that The first measuring module includes at least one weighing sensor, and the at least one weighing sensor is used to support the screw conveyor and measure the force data of the screw conveyor and the clean grain inside the screw conveyor in the vertical direction; Alternatively, the first measuring module includes a tension sensor, which is arranged on a side of the screw conveyor away from the driving shaft and is used to measure force data of the screw conveyor and the clean grain inside the screw conveyor in a vertical direction.

7. A system for measuring grain flow according to claim 6, characterized in that The calculation formula for the grain flow rate includes: m g =m S -m0; Among them, F c represents the data of each weighing sensor, C represents the number of the weighing sensors, G represents the sum of the data of each weighing sensor, a represents the acceleration data, m S represents the mass of the screw conveyor and the clean grain inside the screw conveyor, m0 represents the net weight of the screw conveyor, m g represents the mass of the clean grain inside the screw conveyor, L represents the conveying length of the screw conveyor, p represents the pitch of the screw conveyor, n represents the speed data, t represents the time for the clean grain to pass through the screw conveyor, and Q represents the grain flow rate.

8. The system for measuring grain flow according to claim 7, characterized in that The calculation formula for the grain flow also includes: Among them, t M represents each sampling cycle, N represents the number of revolutions of the screw conveyor in each cycle, Q i represents the grain flow in the ith cycle, m gi represents the mass of clean grain in the i-th sampling period; and when (N1+N2+…+N i )p>L, the parameters in the above calculation formula and The corresponding relationship is as follows: Based on the above calculation formula, the following set of equations can be obtained by combining i measurements and sampling: The above equations are solved through the initialization process to obtain the grain flow rate at the corresponding time.

9. A system for measuring grain flow according to claim 8, characterized in that The calculation process of the grain flow includes a calibration correction process, and the calibration correction process includes the following calculation formula: Q c =KQ r ; Wherein, m1 represents the mass of the screw conveyor and the clean grain inside the screw conveyor, K represents the linear comprehensive error coefficient, Q r represents the grain flow rate before correction, Q c represents the corrected grain flow rate.

10. A harvester, characterized in that: A system for measuring grain flow comprising the system as claimed in any one of claims 1 to 9.

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