Centralized drive type electric drive seeding control system and method matched with running speed of tractor

Abstract

The invention discloses a centralized drive type electric drive seeding control system and method matched with the running speed of a tractor, and relates to the field of agricultural intellectualization, and the system is characterized in that a rotating speed sensor module is fixed at an axle of the tractor; the IMU module is fixed at the mass center of the tractor; the output shaft of the motor driving module is connected with the input shafts of the plurality of seed metering plates which are connected in parallel; the rotating speed sensor module and the IMU module are respectively connected with the data acquisition module; the data acquisition module, the motor driving module and the display and interaction module are respectively connected with the main controller; the main controller is used for effectively fusing the angular speed of the tractor and the longitudinal acceleration of the tractor through a sensor fusion algorithm to obtain the optimal longitudinal speed of the tractor, and sending a control signal to the motor driving module based on the optimal longitudinal speed of the tractor and the corresponding relation between the forward speed of the seeder and the rotating speed of the seed-metering disc; the seeding plate is driven to rotate to finish seeding. According to the application, the quality and efficiency of seeding operation are effectively improved.

Description

Technical Field

[0001] This application relates to the field of intelligent agricultural technology, and in particular to a centralized drive electric seeding control system and method that matches the speed of a tractor. Background Technology

[0002] With the improvement of agricultural intelligence, electric-driven seeding is gradually replacing traditional mechanical transmission methods and has become the core research direction of precision seeding equipment.

[0003] The core objective of precision seeding control is to coordinate the relationship between the seeder's forward speed and the seed metering disc's rotation speed. Currently, precision seeding control systems typically employ two common technical approaches. One is based on a ground wheel system. The principle is that the seeder is equipped with ground wheels, which rotate due to friction with the ground as the tractor pulls the seeder forward. This rotation, after passing through the gearbox, directly drives the seed metering disc in the seed metering unit, thus achieving seed metering. The relationship between the seeder's forward speed and the seed metering disc's rotation speed is determined by the transmission ratio between the ground wheels and the gearbox. This approach is characterized by the passive rotation of the ground wheels. Due to complex soil conditions, the ground wheels are prone to slippage or jamming, making it difficult to accurately control the relationship between the seeder's forward speed and the seed metering disc's rotation speed, thus affecting the consistency of seeding rate and spacing.

[0004] Another approach is based on motor drive. This method uses GPS (or RTK), ground speed radar, and encoders to collect the seeder's speed, and integrates a drive motor on each seed metering unit. The main controller measures the speed in real time and calculates the theoretical rotation speed of the seed metering disc based on preset sowing parameters, then controls the speed of the drive motor directly connected to the seed metering unit. While this approach offers high controllability, the use of high-precision GPS, ground speed radar, and multiple motors results in high overall system energy consumption. Furthermore, its data fusion and system control algorithms are complex and have poor reliability. Therefore, the actual sowing quality and efficiency of both of these approaches are not high. Summary of the Invention

[0005] The purpose of this application is to provide a centralized drive electric seeding control system that matches the speed of a tractor, which effectively improves the quality and efficiency of seeding operations while reducing system energy consumption and ensuring system stability and reliability.

[0006] To achieve the above objectives, this application provides the following solution.

[0007] In a first aspect, this application provides a centralized drive electric seeding control system that matches the speed of a tractor, applied to a tractor-hauled seeder. The seeder is equipped with multiple seed metering discs. The centralized drive electric seeding control system that matches the speed of the tractor includes: a speed sensor module, an IMU module, a data acquisition module, a motor drive module, a display and interaction module, and a main controller. The speed sensor module is fixed at the axle of the tractor; the IMU module is fixed at the center of gravity of the tractor; the output shaft of the motor drive module is connected to the input shafts of the multiple seed metering discs connected in parallel; the speed sensor module and the IMU module are respectively connected to the data acquisition module; the data acquisition module and the motor drive module... The drive module and the display and interaction module are respectively connected to the main controller; the data acquisition module is used to determine the angular velocity of the tractor through the speed sensor module and the longitudinal acceleration of the tractor through the IMU module; the motor drive module is used to simultaneously control the rotational speed of multiple seed metering discs; the display and interaction module is used to set and display the device operating parameters; the main controller is used to effectively fuse the angular velocity and longitudinal acceleration of the tractor through a sensor fusion algorithm to obtain the optimal longitudinal speed of the tractor, and sends a control signal to the motor drive module based on the optimal longitudinal speed of the tractor and the correspondence between the forward speed of the seeder and the rotational speed of the seed metering disc, thereby driving the seed metering disc to rotate and complete the sowing.

[0008] Secondly, this application also provides a centralized drive electric-driven seeding control method for matching tractor travel speed. This method is implemented using the centralized drive electric-driven seeding control system for matching tractor travel speed described in the first aspect. The method includes: determining the tractor's state vector, error covariance matrix, discrete state transition matrix, and process noise covariance matrix; the state vector's components include the tractor's longitudinal speed, longitudinal acceleration, accelerometer bias, and rolling radius scaling factor; based on the optimal state vector and optimal error covariance matrix determined at the previous moment, as well as the discrete state transition matrix and the process noise covariance matrix, predicting the current state vector and error covariance matrix to obtain a priori state vector and a priori error covariance matrix; and based on the priori state vector, the priori error covariance matrix, and the current angular velocity of the tractor. The system updates the wheel speed observation results and performs a first update on the current state vector and error covariance matrix. Based on the first updated state vector and error covariance matrix and the current tractor longitudinal acceleration, the IMU observation results are updated, and a second update is performed on the current state vector and error covariance matrix. When both the current tractor longitudinal acceleration and angular velocity about the tractor are less than a set threshold, the zero-velocity observation results are updated based on the second updated state vector and error covariance matrix, and a third update is performed on the current state vector and error covariance matrix to obtain the current optimal state vector and optimal error covariance matrix. The first element in the optimal state vector is the optimal tractor longitudinal speed. Based on the optimal tractor longitudinal speed, a control signal is sent to the motor drive module according to the correspondence between the seeder's forward speed and the seed metering disc's rotation speed to drive the seed metering disc to rotate and complete the sowing. The optimal tractor longitudinal speed is equal to the seeder's forward speed.

[0009] Based on the specific embodiments provided in this application, the following technical effects are disclosed.

[0010] To address the issue of poor speed measurement accuracy on the ground wheels of traditional seeders, this application shifts the measurement target to the tractor, fully utilizing the tractor's advantage of being heavier and less prone to slippage compared to ground wheels to avoid this problem. To address the high cost and complex algorithms of multi-sensor fusion speed measurement, this application employs a low-cost rotational speed sensor module and an inertial measurement unit (IMU) module. Leveraging the tractor's inherent advantages, the rotational speed sensor module and IMU module are fixed at the tractor's axle and center of gravity, respectively, effectively capturing the tractor's angular velocity and longitudinal acceleration. To reduce the complexity of the control algorithm, this application uses a sensor fusion algorithm to process the above data. Furthermore, this application uses this algorithm to fuse the tractor's angular velocity and longitudinal acceleration, eliminating the influence of errors. The fused result is effectively used to adjust the seed metering disc rotation speed. At this point, the seed metering disc rotation speed is effectively matched with the tractor's travel (longitudinal) speed, thus avoiding the impact of ground wheel slippage on speed matching control and greatly improving seeding accuracy. Furthermore, this application adopts a centralized drive scheme, where each seed tray on the seeder is uniformly driven by a motor drive module. This reduces system complexity and application costs while ensuring consistency between seeding rows. Based on these technical features, this application effectively improves the quality and efficiency of seeding operations while reducing system energy consumption and ensuring system stability and reliability. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of a centralized drive electric seeding control system module that matches the speed of a tractor in one embodiment of this application.

[0013] Figure 2 This is a schematic diagram of the installation of a centralized drive electric seeding control system that matches the speed of a tractor in one embodiment of this application.

[0014] Figure 3 This is a first layout diagram of a speed sensor module in one embodiment of this application.

[0015] Figure 4 This is a second layout diagram of a speed sensor module in one embodiment of this application.

[0016] Figure 5 This is a layout diagram of the motor drive module and the transmission shaft in one embodiment of this application.

[0017] Figure 6 This is a layout diagram of the motor drive module and the broken gearbox shaft in one embodiment of this application.

[0018] Figure 7 This is a layout diagram of the motor drive module and the through shaft without a gearbox in one embodiment of this application.

[0019] Figure 8 This is a layout diagram of the motor drive module and the broken shaft without a gearbox in one embodiment of this application.

[0020] Figure 9 This is a flowchart of a centralized drive electric seeding control method for matching tractor travel speed in another embodiment of this application.

[0021] Reference numerals: Speed ​​sensor module-1, Hall effect speed sensor-11, sensor bracket-12, magnet-13, encoder-14, speed measuring wheel-15, mounting plate-16, bracket-17, preload spring-18, IMU module-2, data acquisition module-3, motor drive module-4, drive motor-41, gearbox-42, mounting base-43, frame-44, power input shaft-45, support plate-46, power output shaft-47, commutator-48, universal joint-49, coupling-50, display and interaction module-5, main controller-6. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Currently, while precision seeding control systems employ two approaches—ground wheel-based and motor-driven—ground wheel-based systems suffer from several drawbacks. Ground wheel-based systems are prone to slippage or jamming due to complex soil conditions, making it difficult to accurately control the relationship between the seeder's forward speed and the seed metering disc's rotation speed, thus affecting the consistency of seeding rate and spacing. Motor-driven systems, on the other hand, suffer from high overall energy consumption, high cost, complex data fusion and system control algorithms, and poor reliability, hindering large-scale practical application. Seeding control methods largely focus on seed metering quality monitoring and compensation, and feedback control based on multi-sensor information—essentially "passive following" control based on real-time feedback, which can only correct problems after they occur.

[0024] The purpose of this application is to provide a centralized drive electric seeding control system that matches the speed of a tractor, which effectively improves the quality and efficiency of seeding operations while reducing system energy consumption and ensuring system stability and reliability.

[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In one exemplary embodiment, a centralized drive-type electric seeding control system matching the travel speed of a tractor is provided, applied to a tractor-hauled seeder, the seeder being equipped with multiple seed metering discs; such as Figure 1 As shown, the centralized drive electric seeding control system that matches the tractor's travel speed includes: a speed sensor module 1, an IMU module 2, a data acquisition module 3, a motor drive module 4, a display and interaction module 5, and a main controller 6.

[0027] like Figure 2 As shown, the speed sensor module 1 is fixed at the axle of the tractor; the IMU module 2 is fixed at the center of gravity of the tractor; the output shaft of the motor drive module 4 is connected to the input shaft of the multiple seed metering discs connected in parallel; the speed sensor module 1 and the IMU module 2 are respectively connected to the data acquisition module 3; the data acquisition module 3, the display and interaction module 5 and the main controller 6 are all located in the cab of the tractor; the data acquisition module 3, the motor drive module 4 and the display and interaction module 5 are respectively connected to the main controller 6. Specifically, the data acquisition module 3 is used to determine the angular velocity of the tractor (i.e., the angular velocity of the tires or the angular velocity of the speed measuring wheel) through the speed sensor module 1, and to determine the longitudinal acceleration of the tractor through the IMU module 2; the motor drive module 4 is used to simultaneously control the rotation speed of multiple seed metering discs; the display and interaction module 5 is used to set and display equipment operating parameters (such as seeding rate per acre, seeder operating speed, cumulative operating area, sowing status, fault information, etc.); the main controller 6 is used to execute a centralized drive electric drive sowing control method that matches the tractor's travel speed. Its core is to effectively fuse the angular velocity and longitudinal acceleration of the tractor through a sensor fusion algorithm (i.e., Kalman filter) to obtain the optimal longitudinal speed of the tractor (also known as the optimal forward speed of the tractor), and send a control signal to the motor drive module 4 based on the optimal longitudinal speed of the tractor and the correspondence between the forward speed of the seeder and the rotation speed of the seed metering disc, so as to drive the seed metering disc to rotate and complete the sowing.

[0028] As a preferred embodiment, such as Figure 3As shown, one configuration of the speed sensor module 1 includes a Hall effect speed sensor 11, a sensor bracket 12, and multiple magnets 13. The fixed end of the sensor bracket 12 is mounted on the tractor's axle, and the extended end of the sensor bracket 12 is located on the outside of the tractor's wheel hub flange. The Hall effect speed sensor 11 is fixed to the extended end of the sensor bracket 12. The multiple magnets 13 are evenly attached to the outer ring of the tractor's wheel hub flange at a set interval. The Hall effect speed sensor 11 is connected to the data acquisition module 3. In actual operation: the magnets 13 on the outer ring of the wheel hub flange rotate with the tractor's tires. The magnets 13 continuously approach or move away from the probe of the Hall effect speed sensor 11. The Hall effect speed sensor 11 outputs a corresponding pulse signal to the data acquisition module 3, and the data acquisition module 3 processes the pulse signal according to its frequency. f and the number of magnets on the outer ring of the wheel hub flange N Calculate the angular velocity of the tire ,Right now angular velocity The state variables subsequently observed by the Kalman filter allow the main controller 6 to calculate the tractor's forward (i.e., longitudinal) speed based on the angular velocity and the tire radius. v ,Right now .

[0029] As another preferred embodiment, such as Figure 4 As shown, another configuration of the speed sensor module 1 includes an encoder 14, a speed measuring wheel 15, a mounting plate 16, a bracket 17, and a preload spring 18. The mounting plate 16 is fixed to the tractor's axle (or alternatively, to the front of a seeder) using bolts. One end of the bracket 17 is connected to the mounting plate 16 via a pin, allowing the bracket 17 to rotate around the pin. The other end of the bracket 17 has a side plate. The encoder 14 is fixed to the side plate with bolts. The shaft of the encoder 14 is connected to the shaft of the speed measuring wheel 15 via a key. A bearing is mounted on the shaft of the speed measuring wheel 15. The outer ring of the bearing of the speed measuring wheel 15 is embedded in the side plate. The preload spring 18 connects the holes on the mounting plate 16 and the bracket 17 to bring the speed measuring wheel 15 close to the ground (the tension of the preload spring 18 can be adjusted by changing the stiffness coefficient of the preload spring 18 or by changing the hole position on the bracket 17, thereby adjusting the ground contact effect of the speed measuring wheel 15). The encoder 14 is connected to the data acquisition module 3. In actual operation: the speed measuring wheel 15 rotates close to the ground as the tractor moves forward, driving the encoder 14 to output corresponding pulse signals. The data acquisition module 3 then calculates the pulse signals based on their frequency. f and the resolution of encoder 14 M Calculate the angular velocity of the speed measuring wheel 15. ,Right now angular velocity The state variables of the Kalman filter are subsequently used for observation. The main controller 6 can calculate the forward (i.e., longitudinal) speed of the tractor based on the angular velocity and the radius of the speed measuring wheel 15. ,Right now .

[0030] In a preferred embodiment, the IMU module 2 includes an IMU, a rigid bracket, and anti-loosening bolts. The IMU is fixed at the center of mass of the tractor by the rigid bracket and anti-loosening bolts (to avoid increased measurement noise or relative motion due to vibration) (to reduce acceleration measurement errors caused by vehicle rotation). The sensitive axis of the IMU should be aligned with the vehicle coordinate system, i.e., the X-axis of the IMU points to the forward direction of the tractor, the Y-axis points to the left of the forward direction, and the Z-axis is vertically upward (consistent with the right-hand coordinate system). The IMU is connected to the data acquisition module 3. The data acquisition module 3 acquires the longitudinal acceleration of the tractor through the IMU. The main controller 6 can obtain the forward (i.e., longitudinal) speed of the tractor by integrating this acceleration.

[0031] In a preferred embodiment, when the motor drive module 4 includes an independent drive motor 41 and the seeder has a gearbox 42, the output shaft of the drive motor 41 is connected to the input shaft of the gearbox 42, and the input shafts of multiple seed metering discs are connected in parallel to the output shaft of the gearbox 42. Figure 5 As shown, the drive motor 41, gearbox 42, mounting base 43, and frame 44 are connected by bolts. The two ends of the power input shaft 45 are inserted into the inner square holes of the drive motor 41 and gearbox 42 respectively (for transmitting power). The drive motor 41 can be a 12V or 24V DC motor. The gearbox 42 has several gears to adjust the input and output transmission ratio. The support plates 46 on both sides of the frame 44 are fixed to the frame 44 with bolts at one end and have holes at the other end for bearings. The power output shafts 47 pass through the inner holes of the bearings. The support plates 46 are mainly used to support the rotation of the power output shafts 47. The power output shafts 47 are square shafts, which are directly inserted into the square through holes in the (90-degree) commutator 48 for connection. The (90-degree) commutator 48 is used to change the direction of rotation, transmitting the speed of the power output shaft 47 to the universal joint 49. The universal joint 49 further transmits the speed to the seed metering device, driving its seed metering disc to rotate and achieve seed metering. The commutator output shaft and the universal joint shaft are directly fastened together by bolts.

[0032] The advantages of the above method are: the gearbox 42 has preset gears, which can be set to a gear near the desired speed according to the sowing requirements. At this time, the speed of the drive motor 41 only needs minor adjustments to meet the requirements, reducing control difficulty. Furthermore, the seeder has a wide speed range, making it adaptable to a wide range of applications. Simultaneously, by setting the gears reasonably, the drive motor 41 can operate in the high-efficiency range, reducing the overall energy efficiency of the system. However, the power output shaft 47 in the above scheme is a complete long shaft. If the number of sowing rows is large, the length of the power output shaft 47 will be too long, which may lead to deformation of the power output shaft 47, misalignment of the two ends, increased rotational resistance, increased system energy consumption, or even rotational jamming. In this case, the following solution can be adopted: Figure 6 As shown, the power output shaft 47 is broken into several sections, each of which is supported at both ends by a support plate 46. One or more seeders share a power output shaft 47. Adjacent power output shafts 47 are connected by a coupling 50 or a universal joint 49. At this time, slight misalignment between the power output shafts 47 is allowed, which can avoid system jamming and increased energy consumption.

[0033] In another preferred embodiment, when the motor drive module 4 includes an independent drive motor 41 and the seeder does not have a gearbox 42, the input shafts of multiple seed metering discs are connected in parallel to the output shaft of the drive motor 41. Figure 7 As shown, the power output shaft 47 is directly inserted into the inner square hole of the drive motor 41 for power transmission. Its advantages include reducing transmission links and improving transmission efficiency. However, its disadvantages include a smaller speed range, and under extreme conditions, the drive motor 41 operating in an inefficient range may lead to increased energy consumption or reduced lifespan. Furthermore, the power output shaft 47 in the above scheme is also a long shaft. If the number of seeding rows is large, the length of the power output shaft 47 will be excessive, which may lead to deformation of the power output shaft 47, misalignment of the two ends, increased rotational resistance, increased system energy consumption, or even rotational jamming. In this case, the following solution can be adopted: Figure 8 As shown, the power output shaft 47 is broken into several sections, each of which is supported at both ends by a support plate 46. One or more seeders share a power output shaft 47. Adjacent power output shafts 47 are connected by a coupling 50 or a universal joint 49. At this time, slight misalignment between the power output shafts 47 is allowed, which can avoid system jamming and increased energy consumption.

[0034] In another preferred embodiment, the display and interaction module 5 is an LCD screen. Its main interface can display information such as sowing parameters, and the secondary setting interface can set the sowing rate per acre. During normal sowing operations, the main interface mainly displays the current sowing machine operating speed, cumulative operating area, real-time sowing rate of the current row, and sowing status (normal, missed sowing, double sowing, broken row). When the system determines that there is a missed sowing / double sowing, a text alarm will be displayed on the LCD screen to remind the driver to take action; when the system determines that there is a broken row, a text alarm will be displayed on the LCD screen, and the drive motor 41 will stop working, the main interface will flash, and the driver will be forced to intervene, thereby avoiding substandard sowing quality and providing the driver with comprehensive operational decision support.

[0035] Based on the above analysis, this embodiment utilizes a low-cost Hall effect speed sensor to measure the angular velocity of the tractor tires or an encoder to measure the angular velocity of the speed measuring wheel. Simultaneously, it centrally drives multiple seeders using a single drive motor, thus offering advantages such as low energy consumption, low system complexity, low application cost, and high reliability. This embodiment also uses the tractor's longitudinal speed as the primary basis for adjusting the seed metering disc speed, reducing the impact of ground wheel slippage on speed matching control and improving sowing accuracy. The drive motor-transmission-power output shaft transmission method in this embodiment offers advantages such as a wide speed range and low energy consumption, avoiding the problem of performance degradation or failure caused by the drive motor operating in an inefficient region for extended periods.

[0036] In another exemplary embodiment, a centralized drive electric seeding control method matching the tractor's travel speed is provided, which is implemented through the aforementioned centralized drive electric seeding control system matching the tractor's travel speed, as follows: Figure 9 As shown, the centralized drive electric seeding control method that matches the tractor's travel speed is as follows.

[0037] Step S1: Determine the tractor's state vector, error covariance matrix, discrete state transition matrix, and process noise covariance matrix.

[0038] Define the state vector of the tractor , For the longitudinal speed of the tractor, For the longitudinal acceleration of the tractor, To achieve zero bias in the accelerometer, This is the rolling radius scaling factor (used to adaptively learn the actual rolling radius of the wheel and compensate for the effects of factors such as tire wear and tire pressure changes).

[0039] The discrete-time state transition model (process model) of the tractor can then be expressed as: , and They are respectively k Time andk The state vector at time -1 for k The process noise vector at time step 1, and F is the discrete state transition matrix.

[0040] Wherein, the discrete state transition matrix , For time difference.

[0041] Process noise vector , , , and They are respectively , , and The corresponding process noise.

[0042] Process noise covariance matrix , Represents a diagonal matrix. , , and They are respectively , , and The corresponding process noise covariance.

[0043] In addition, the state vector needs to be processed before starting the Kalman filter. Error covariance matrix P, process noise vector w, process noise covariance matrix Q, and vehicle speed observation noise Acceleration observation noise and zero-velocity observation noise Perform initialization.

[0044] Step S2: Based on the optimal state vector and optimal error covariance matrix determined in the previous time step, as well as the discrete state transition matrix and process noise covariance matrix, predict the state vector and error covariance matrix at the current time step to obtain the prior state vector and prior error covariance matrix.

[0045] In this embodiment, the formulas for calculating the prior state vector and the prior error covariance matrix are as follows.

[0046] .

[0047] .

[0048] In the formula, and They are respectively kThe prior state vector and prior error covariance matrix at time t; and They are respectively k The optimal state vector and optimal error covariance matrix determined at time -1; This represents the rank transformation of the discrete state transition matrix.

[0049] Step S3: Update the wheel speed observation results based on the prior state vector, the prior error covariance matrix, and the angular velocity of the tractor at the current moment, and perform the first update on the state vector and error covariance matrix at the current moment.

[0050] In this embodiment, the wheel speed observation results include the first residual. First residual covariance and the first Kalman gain The process of updating the wheel speed observation results is as follows.

[0051] .

[0052] .

[0053] .

[0054] In the formula, The longitudinal speed observation value of the tractor; This is the longitudinal speed observation matrix for tractors. express Transitions; for k The angular velocity of the tractor at any given time (when using a Hall effect speed sensor for measurement). for k The angular velocity of the (tractor) tire at any given time; when using a speed measuring wheel for measurement, for k (The angular velocity of the speed measuring wheel at all times). R The radius of the tire or the radius of the speed measuring wheel (when using a Hall effect speed sensor). R Where is the radius of the tire; when using a speed measuring wheel for measurement, R (where the radius is the speed measuring wheel). The rolling radius scaling factor is determined by utilizing... calculated; calculated This represents the inverse of the first residual covariance.

[0055] Meanwhile, the process of updating the state vector and error covariance matrix at the current moment for the first time is as follows.

[0056] .

[0057] .

[0058] In the formula, and Let I be the state vector and error covariance matrix after the first update, respectively; I is the identity matrix.

[0059] Step S4: Update the IMU observation results based on the updated state vector and error covariance matrix and the tractor longitudinal acceleration at the current time, and perform a second update on the state vector and error covariance matrix at the current time.

[0060] In this embodiment, the IMU observation results include the second residual. Second residual covariance Second Kalman gain The process of updating IMU observation results is as follows.

[0061] .

[0062] .

[0063] .

[0064] In the formula, The longitudinal acceleration of the tractor is the observed value. This is the longitudinal acceleration observation matrix for the tractor, and this matrix is ​​fixed. express Transitions; for k The longitudinal acceleration of the tractor at any given moment; To achieve zero bias in the accelerometer, it is achieved by utilizing... calculated; calculated This represents the inverse of the second residual covariance.

[0065] Meanwhile, the process of updating the state vector and error covariance matrix at the current moment for the second time is as follows.

[0066] .

[0067] .

[0068] In the formula, and These are the state vector and error covariance matrix after the second update, respectively.

[0069] Step S5: When the longitudinal acceleration and angular velocity of the tractor at the current moment are both less than the set threshold, update the zero velocity observation result based on the updated state vector and error covariance matrix, and perform a third update on the state vector and error covariance matrix at the current moment to obtain the optimal state vector and optimal error covariance matrix at the current moment.

[0070] In this embodiment, if both the longitudinal acceleration and angular velocity of the tractor at the current moment are less than a set threshold, the tractor is determined to be stationary. When the tractor is not stationary, the observation update ends. That is, the latest state vector. This is the latest error covariance matrix; otherwise, the state vector and error covariance matrix at the current time are updated for the third time.

[0071] The zero-velocity observation results include the third residual. Third residual covariance and the third Kalman gain The process of updating the zero-velocity observation results is as follows.

[0072] .

[0073] .

[0074] .

[0075] In the formula, This is the observed value of the tractor's longitudinal acceleration. Since the tractor is determined to be stationary at this point, therefore... =0; This is the longitudinal acceleration observation matrix for the tractor, and this matrix is ​​fixed. express Transitions; This represents the inverse of the third residual covariance.

[0076] Meanwhile, the process of updating the state vector and error covariance matrix for the current moment for the third time is as follows.

[0077] .

[0078] .

[0079] In the formula, and They are respectively k The optimal state vector and optimal error covariance matrix at time t.

[0080] Finally, the optimal state vector The first element in the equation is determined as the optimal longitudinal speed of the tractor.

[0081] Step S6: Based on the optimal longitudinal speed of the tractor, a control signal is sent to the motor drive module according to the correspondence between the forward speed of the seeder and the rotation speed of the seed metering disc, so as to drive the seed metering disc to rotate and complete the sowing.

[0082] In this embodiment, the optimal longitudinal speed of the tractor is equivalent to the optimal forward speed of the seeder. By setting the correspondence between the forward speed of the seeder and the rotational speed of the seed metering disc, the forward speed of the seeder can be converted into the rotational speed of the seed metering disc, which is called matching the forward speed of the seeder. Because the accuracy of the predicted optimal longitudinal speed of the tractor in this embodiment is high, the accuracy of the corresponding rotational speed of the seed metering disc is also high, thus effectively improving the efficiency and quality of sowing.

[0083] In summary, this application has the following main advantages.

[0084] (1) Using the forward speed of the tractor as the basis for controlling the drive motor reduces the impact of wheel slippage on speed matching control and is beneficial to improving sowing accuracy.

[0085] (2) The seed metering disc of the seeder adopts a centralized control method. The drive motor is connected to the reducer of the seeder. One drive motor controls multiple seed metering discs, which helps to reduce energy consumption and avoids the drive motor running in an inefficient area for a long time, which would lead to performance degradation or failure.

[0086] (3) The power output shaft can be either integral or segmented. The segmented power output shaft connection method can reduce the increase in energy consumption and system jamming caused by deformation or different shafts.

[0087] (5) The Kalman filter is used to fuse the tractor's angular velocity and longitudinal acceleration to estimate the tractor's forward speed, which effectively improves the accuracy of vehicle speed estimation in complex scenarios such as tire slippage, wear, tire pressure changes, and soil condition changes.

[0088] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0089] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A centralized drive-type electric seeding control system that matches the travel speed of a tractor, applied to a tractor-hauled seeder, wherein the seeder is equipped with multiple seed metering discs, characterized in that, The centralized drive electric seeding control system that matches the tractor's travel speed includes: a speed sensor module, an IMU module, a data acquisition module, a motor drive module, a display and interaction module, and a main controller; The speed sensor module is fixed at the axle of the tractor; the IMU module is fixed at the center of gravity of the tractor; the output shaft of the motor drive module is connected to the input shaft of the multiple seed metering discs connected in parallel; the speed sensor module and the IMU module are respectively connected to the data acquisition module; the data acquisition module, the motor drive module and the display and interaction module are respectively connected to the main controller. The data acquisition module is used to determine the angular velocity of the tractor through the speed sensor module and the longitudinal acceleration of the tractor through the IMU module; the motor drive module is used to simultaneously control the rotational speed of multiple seed metering discs; the display and interaction module is used to set and display the device operating parameters; the main controller is used to effectively fuse the angular velocity and longitudinal acceleration of the tractor through a sensor fusion algorithm to obtain the optimal longitudinal speed of the tractor, and sends a control signal to the motor drive module based on the optimal longitudinal speed of the tractor and the correspondence between the forward speed of the seeder and the rotational speed of the seed metering discs, thereby driving the seed metering discs to rotate and complete the sowing.

2. The centralized drive electric seeding control system for matching tractor travel speed according to claim 1, characterized in that, The speed sensor module includes a Hall-effect speed sensor, a sensor bracket, and multiple magnets; The fixed end of the sensor bracket is mounted on the axle of the tractor, and the extended end of the sensor bracket is located outside the wheel hub flange of the tractor; the Hall effect speed sensor is fixed to the extended end of the sensor bracket; a plurality of magnets are evenly pasted on the outer ring of the wheel hub flange of the tractor at a set interval; the Hall effect speed sensor is connected to the data acquisition module. The magnet on the outer ring of the wheel hub flange rotates together with the tractor's tire. The magnet continuously approaches or moves away from the probe of the Hall effect speed sensor. The Hall effect speed sensor outputs a corresponding pulse signal to the data acquisition module. The data acquisition module calculates the angular velocity of the tire based on the frequency of the pulse signal and the number of magnets on the outer ring of the wheel hub flange.

3. The centralized drive electric seeding control system for matching tractor travel speed according to claim 1, characterized in that, The speed sensor module includes an encoder, a speed measuring wheel, a mounting plate, a bracket, and a preload spring; The mounting plate is fixed to the tractor's axle; one end of the bracket is connected to the mounting plate via a pin, and the bracket can rotate around the pin; the other end of the bracket is provided with a side plate; the encoder is fixed to the side plate by bolts; the encoder shaft is connected to the speed measuring wheel shaft via a key; the outer ring of the speed measuring wheel's bearing is embedded in the side plate; the preload spring connects the mounting plate and the hole on the bracket to make the speed measuring wheel close to the ground; the encoder is connected to the data acquisition module. The speed measuring wheel rotates along the ground as the tractor moves forward, driving the encoder to output a corresponding pulse signal. The data acquisition module calculates the angular velocity of the speed measuring wheel based on the frequency of the pulse signal and the resolution of the encoder.

4. The centralized drive electric seeding control system for matching tractor travel speed according to claim 1, characterized in that, The IMU module includes an IMU, a rigid bracket, and anti-loosening bolts; The IMU is fixed to the center of gravity of the tractor by the rigid bracket and the anti-loosening bolt; the X-axis of the IMU points to the forward direction of the tractor, the Y-axis points to the left of the forward direction, and the Z-axis is vertically upward. The IMU is connected to the data acquisition module; the data acquisition module obtains the longitudinal acceleration of the tractor through the IMU.

5. The centralized drive electric seeding control system for matching tractor travel speed according to claim 1, characterized in that, The motor drive module includes an independent drive motor; When the seeder has a gearbox, the output shaft of the drive motor is connected to the input shaft of the gearbox, and the input shafts of the multiple seed metering discs are connected in parallel to the output shaft of the gearbox; When the seeder does not have a gearbox, the input shafts of the multiple seed metering discs are connected in parallel to the output shaft of the drive motor.

6. A centralized drive electric seeding control method for matching tractor travel speed, characterized in that, The centralized drive electric seeding control method for matching tractor travel speed is implemented by the centralized drive electric seeding control system for matching tractor travel speed as described in any one of claims 1-5, wherein the centralized drive electric seeding control method for matching tractor travel speed includes: The state vector, error covariance matrix, discrete state transition matrix, and process noise covariance matrix of the tractor are determined; the components of the state vector include the tractor's longitudinal velocity, tractor's longitudinal acceleration, accelerometer zero bias, and rolling radius scaling factor. Based on the optimal state vector and optimal error covariance matrix determined in the previous moment, as well as the discrete state transition matrix and the process noise covariance matrix, the state vector and error covariance matrix at the current moment are predicted to obtain the prior state vector and prior error covariance matrix. Based on the prior state vector, the prior error covariance matrix, and the current angular velocity of the tractor, update the wheel speed observation results, and perform the first update on the current state vector and error covariance matrix; The IMU observations are updated based on the state vector and error covariance matrix after the first update, as well as the longitudinal acceleration of the tractor at the current moment. The state vector and error covariance matrix at the current moment are then updated a second time. When the longitudinal acceleration and angular velocity of the tractor at the current moment are both less than the set threshold, the zero-velocity observation result is updated based on the state vector and error covariance matrix after the second update, and the state vector and error covariance matrix at the current moment are updated for the third time to obtain the optimal state vector and optimal error covariance matrix at the current moment; the first element in the optimal state vector is the optimal longitudinal velocity of the tractor. Based on the optimal longitudinal speed of the tractor, a control signal is sent to the motor drive module according to the correspondence between the forward speed of the seeder and the rotation speed of the seed metering disc, driving the seed metering disc to rotate and complete the sowing; the optimal longitudinal speed of the tractor is equal to the forward speed of the seeder.

7. The centralized drive electric seeding control method for matching tractor travel speed according to claim 6, characterized in that, The formulas for calculating the prior state vector and the prior error covariance matrix are as follows: ； ； In the formula, and They are respectively k The prior state vector and prior error covariance matrix at time t; and They are respectively k The optimal state vector and optimal error covariance matrix determined at time -1; F is the discrete state transition matrix. Let F denote the rank transformation of F; Q is the process noise covariance matrix.

8. The centralized drive electric seeding control method for matching tractor travel speed according to claim 6, characterized in that, The wheel speed observation results include the first residual, the first residual covariance, and the first Kalman gain; The formula for updating the wheel speed observation results is: ； ； ； In the formula, The first residual; The longitudinal speed observation value of the tractor; This is the longitudinal speed observation matrix for tractors. express Transitions; for k The angular velocity of the tractor at any given moment; R This refers to the radius of the tire or the radius of the speed measuring wheel; This is the rolling radius scaling factor; The first residual covariance, express The reverse; for k The prior error covariance matrix at time t; Noise was observed based on vehicle speed; The first Kalman gain; The formula for the first update of the state vector and error covariance matrix at the current moment is: ； ； In the formula, and These are the state vector and error covariance matrix after the first update, respectively; for k The prior state vector at time t; I is the identity matrix.

9. The centralized drive electric seeding control method for matching tractor travel speed according to claim 6, characterized in that, The IMU observation results include the second residual, the second residual covariance, and the second Kalman gain; The formula for updating the IMU observation results is: ； ； ； In the formula, The second residual; The longitudinal acceleration of the tractor is the observed value. This is the longitudinal acceleration observation matrix for tractors. express Transitions; This is the state vector after the first update; for k The longitudinal acceleration of the tractor at any given moment; To achieve zero bias in the accelerometer; The second residual covariance, express The reverse; This is the error covariance matrix after the first update; For acceleration observation noise; This is the second Kalman gain; The formula for the second update of the current state vector and error covariance matrix is ​​as follows: ； ； In the formula, and These are the state vector and error covariance matrix after the second update, respectively; I is the identity matrix.

10. The centralized drive electric seeding control method for matching tractor travel speed according to claim 6, characterized in that, The zero-velocity observation results include the third residual, the third residual covariance, and the third Kalman gain; The formula for updating the zero-velocity observation results is: ； ； ； In the formula, The third residual; The longitudinal acceleration of the tractor is the observed value. This is the longitudinal acceleration observation matrix for tractors. express Transitions; This is the state vector after the second update; The third residual covariance, express The reverse; This is the error covariance matrix after the second update; Zero-velocity observation noise; This is the third Kalman gain; The formula for the third update of the current state vector and error covariance matrix is ​​as follows: ； ； In the formula, and They are respectively k The optimal state vector and optimal error covariance matrix at time t; I is the identity matrix.

Images