Synchronous control system for seeding depth and plant spacing of electric drive seeder

Abstract

The present application relates to the technical field of agricultural machinery automation control, and discloses a kind of electric drive seeding machine seeding depth and plant spacing synchronous control system, including velocity radar, attitude module, force sensor, angle sensor, control unit, depth adjusting push rod, seed metering execution assembly.The present application is synchronized to read data alignment time stamp by acquisition module, horizontal velocity is generated by solving module in combination with oblique velocity and pitch angle, chassis slip amount is generated according to filter pressure by prediction module, time deviation amount is generated by solving module to filter depth, target frequency is generated by generating module fusion horizontal velocity, chassis slip amount and time deviation amount to execute orthogonal vector synthesis, push rod parameter is generated by generating module fusion filter pressure and horizontal velocity to execute fuzzy algorithm and introduce cross coupling compensation calculation duty ratio, control unit responds hardware trigger pulse and issues instruction in parallel to eliminate time delay difference and hysteresis error, and realizes seeding depth and plant spacing synchronous control.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery automation control technology, specifically to a synchronous control system for the sowing depth and plant spacing of an electric-driven seeder. Background Technology

[0002] Electric-driven seeders perform seeding tasks in field operations. The control system needs to adjust the operating parameters of the seed metering motor to control the plant spacing, and simultaneously adjust the output parameters of the depth adjustment push rod to control the furrowing depth. Existing control systems suffer from hardware scheduling limitations in the data acquisition and command issuance stages. The speed radar, attitude module, force sensor, and angle sensor are distributed at different nodes in the chassis structure, making it difficult for the control system to align the timestamps of the output signals from each sensor, resulting in data time differences.

[0003] After the calculation is completed, the control unit relies on software serial logic to send control commands to the seed metering motor and the depth adjustment push rod. The software serial sending mechanism generates a delay difference in instruction execution inside the microprocessor, which causes the seeding depth adjustment action and the plant spacing adjustment action to be out of sync.

[0004] When an electric-driven seeder operates on slopes or in undulating terrain, the slant velocity detected by the speed-measuring radar has a slope vector component. Directly using this slant velocity to calculate plant spacing will introduce fundamental errors. The soil generates dynamic traction resistance on the depth adjustment push rod. Increased traction resistance causes momentary slippage of the chassis drive wheels. This slippage reduces the actual forward displacement speed of the electric-driven seeder, resulting in hysteresis errors in the plant spacing control loop.

[0005] The combination of terrain undulations and the downward action of the depth-adjusting push rod changes the absolute height of the seed metering device relative to the ground. This change in absolute height forces the seed metering device to produce a vertical displacement. This vertical displacement causes the inner wall of the seed guide tube to impact the seeds. The impact of the inner wall on the seeds generates frictional resistance, delaying the seed's fall. This delay in the fall causes a longitudinal shift in the seed metering landing position, disrupting the constant state of the standard plant spacing.

[0006] The field operation environment contains high-frequency mechanical vibrations, which inject white noise into the sensors. The original pressure and original depth are mixed with white noise. The white noise disrupts the convergence state of the data differentiation calculation of the control system, resulting in distortion of the acquired velocity and acceleration variables.

[0007] When adjusting the sowing depth, the position of the individual mechanical structure of the depth-adjusting push rod changes. This change in position generates transient cross-coupling interference on the load of the seed metering motor, causing fluctuations in the output speed of the seed metering motor. The existing control framework lacks a mechanism to extract corresponding compensation variables for transient cross-coupling interference and incorporate them into the motor control command calculation process. This results in mutual interference between sowing depth and plant spacing control, affecting the coordinated control effect of the sowing system.

[0008] Therefore, this invention proposes a synchronous control system for the sowing depth and plant spacing of an electric-driven seeder to address the shortcomings of existing technologies. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a synchronous control system for sowing depth and plant spacing in an electric-driven seeder. It solves the problems of asynchronous sowing depth and plant spacing adjustments caused by misaligned sensor data reading timestamps and delays in command execution due to software serial transmission mechanisms. It also addresses the issues of slope vector components in the diagonal speed output from the speed measuring radar, instantaneous slippage of the chassis drive wheels due to soil traction resistance fluctuations, and delays in seed falling caused by vertical displacement of the seed metering device, all of which disrupt the constant standard plant spacing. Furthermore, it resolves the problems of high-frequency mechanical vibration injecting white noise into the sensors, disrupting the convergence state of data differentiation calculations, and transient cross-coupling interference caused by changes in the position of the depth adjustment push rod's individual mechanical structure, leading to mutual interference in the control loop.

[0010] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a synchronous control system for the sowing depth and plant spacing of an electric-driven seeder, including a speed measuring radar, an attitude module, a force sensor, an angle sensor, a control unit, a depth adjustment push rod, and a seed metering assembly.

[0011] The seed metering assembly includes a seed metering motor, a seed metering device driven by the seed metering motor, and a seed guide tube connected to the seed metering device. The speed radar establishes a signal connection with the control unit, the attitude module establishes a signal connection with the control unit, the force sensor establishes a signal connection with the control unit, the angle sensor establishes a signal connection with the control unit, the control unit establishes an electrical connection with the depth adjustment push rod, and the control unit establishes an electrical connection with the seed metering motor. The control unit internally integrates a data acquisition module, a filtering module, a calculation module, a prediction module, a generation module, pulse width modulation peripherals, and digital-to-analog conversion peripherals.

[0012] The data acquisition module receives oblique velocity from the speed measuring radar, pitch angle from the attitude module, raw pressure from the force sensor, and raw depth from the angle sensor. The acquisition module also integrates a timer hardware circuit to generate fixed-period interrupt signals.

[0013] The acquisition module synchronously performs oblique velocity reading, pitch angle reading, voltage signal analog-to-digital conversion, and current signal analog-to-digital conversion operations based on fixed-period interrupt signals, ensuring that oblique velocity, pitch angle, original pressure, and original depth are aligned to the same timestamp node.

[0014] The filtering module applies a one-dimensional Kalman filter algorithm to the original pressure to generate filtered pressure, and applies a one-dimensional Kalman filter algorithm to the original depth to generate filtered depth.

[0015] The solution module performs a cosine mapping operation on the pitch angle to generate attitude compensation coefficients. It then combines the oblique velocity with the attitude compensation coefficients to perform a multiplication operation to generate the horizontal velocity, completing the spatial dimension reduction projection calculation. The prediction module calculates the difference between the filtered pressure and the basic drag threshold, and marks the difference as additional drag when it is greater than zero.

[0016] The prediction module multiplies the additional drag and the slip ratio coefficient to generate the chassis slip. The solution module performs first-order time derivative and moving average filtering on the filter depth to generate the vertical velocity. The solution module performs second-order time derivative and moving average filtering on the vertical velocity to generate the vertical acceleration. The solution module multiplies the vertical velocity and the velocity-friction coefficient to generate the velocity deviation component, multiplies the vertical acceleration and the acceleration-friction coefficient to generate the acceleration deviation component, and adds the velocity deviation component and the acceleration deviation component to generate the time deviation.

[0017] The generation module calculates the difference between the horizontal speed and the chassis slippage to generate a compensation speed. The generation module then multiplies the compensation speed by the time deviation to generate the dynamic spacing compensation. Finally, the generation module adds the standard plant spacing to the dynamic spacing compensation to generate the actual composite plant spacing.

[0018] When the actual synthetic plant spacing is lower than the minimum amplitude threshold, the generation module forcibly clamps the actual synthetic plant spacing to the minimum amplitude threshold. The generation module calculates the target frequency by dividing the compensation speed by the actual synthetic plant spacing, thus completing the orthogonal vector synthesis operation.

[0019] The generation module performs a mapping calculation on the filtered pressure input pressure membership function to generate a pressure fuzzy vector, and the generation module performs a mapping calculation on the horizontal velocity input velocity membership function to generate a velocity fuzzy vector.

[0020] The fuzzy rule control matrix defines the correspondence between the pressure fuzzy vector, the velocity fuzzy vector and the output compensation weight. When the pressure fuzzy vector represents an increase in filtering pressure and the velocity fuzzy vector represents an increase in horizontal velocity, it is determined that the dynamic impact resistance of the depth adjustment push rod increases and the output compensation weight increases nonlinearly. When the pressure fuzzy vector represents a decrease in filtering pressure and the velocity fuzzy vector represents a decrease in horizontal velocity, it is determined that the force tends to be gentle and the output compensation weight decays and approaches the basic preset constant.

[0021] The generation module iterates through the fuzzy rule control matrix based on the pressure and velocity fuzzy vectors to extract matching rules and generate a weighted fuzzy set. The generation module then performs centroid-based analytical calculations on the weighted fuzzy set to generate output compensation weights. Finally, the generation module multiplies the output compensation weights with the basic pushrod parameters to generate the pushrod parameters.

[0022] The generation module incorporates a cross-coupling compensation algorithm, using the push rod parameters as a real-time compensation term in the motor control command duty cycle calculation process. The generation module generates the push rod control command voltage value based on the push rod parameters. The control unit generates a hardware trigger strobe pulse through a synchronous timer circuit.

[0023] The control unit controls the dual-channel direct memory access controller to respond to the hardware-triggered strobe pulse. Within the same system clock cycle, it writes the motor control command duty cycle into the first pulse width modulation output register and writes the push rod control command voltage value into the digital-to-analog converter output register, thereby achieving hardware-level parallel alignment of control commands.

[0024] The first pulse width modulation output register converts the motor control command duty cycle into the corresponding pulse width modulation waveform and sends it to the seeding motor. The response pulse width modulation waveform performs the plant spacing synchronization adjustment action. The digital-to-analog conversion output register converts the push rod control command voltage value into the corresponding analog voltage signal and sends it to the depth adjustment push rod. The response analog voltage signal performs the sowing depth synchronization adjustment action.

[0025] This invention provides a synchronous control system for the sowing depth and plant spacing of an electric-driven seeder, which has the following beneficial effects: 1. This invention ensures that the oblique speed, pitch angle, original pressure, and original depth are aligned to a consistent timestamp node by synchronously executing reading and analog-to-digital conversion operations based on the fixed-period interrupt signal generated by the timer hardware circuit through the acquisition module. The control unit controls the dual-channel direct memory access controller to respond to the hardware-triggered strobe pulse and write the motor control command duty cycle into the first pulse width modulation output register and the push rod control command voltage value into the digital-to-analog conversion output register within the same system clock cycle, eliminating the time delay difference caused by software serial transmission and realizing synchronous control of sowing depth and plant spacing.

[0026] 2. This invention generates horizontal velocity by performing spatial dimension reduction projection calculation using a solution module that combines oblique velocity and pitch angle. A prediction module generates chassis slippage based on the difference between filter pressure and foundation resistance threshold. A solution module generates time deviation by combining vertical velocity and vertical acceleration generated by the derivative of filter depth. A generation module merges horizontal velocity, chassis slippage, and time deviation to perform orthogonal vector synthesis calculation to generate target frequency. This eliminates the influence of slope topography components, instantaneous slippage of chassis drive wheels caused by traction resistance fluctuations, and plant spacing hysteresis error caused by delay in seed falling due to vertical displacement of the seed metering device, thus maintaining a constant standard plant spacing.

[0027] 3. This invention uses a filtering module to perform a one-dimensional Kalman filter algorithm model on the original pressure and original depth to filter out the white noise mixed with high-frequency mechanical vibration, ensuring the convergence state of the derivative operation. The generation module extracts matching rules and generates push rod parameters by traversing the fuzzy rule control matrix based on the filtered pressure and horizontal velocity. A cross-coupling compensation algorithm is introduced to incorporate the push rod parameters as real-time compensation terms into the motor control command duty cycle calculation process, eliminating the transient cross-coupling interference caused by the change in the position of the individual mechanical structure of the depth adjustment push rod on the load of the seeding motor when adjusting the seeding depth. Attached Figure Description

[0028] Figure 1 This is a system block diagram of the present invention.

[0029] Figure 2 This is a flowchart illustrating a method for synchronously controlling the sowing depth and plant spacing of an electric-driven seeder provided by the present invention.

[0030] Figure 3 This is a schematic diagram of the signal acquisition and Kalman filtering process in step S100 of the present invention.

[0031] Figure 4 This is a schematic diagram of the process for calculating horizontal speed, predicting chassis slip, and generating time deviation in steps S200 and S300 of the present invention.

[0032] Figure 5 This is a schematic diagram of the process of generating the target frequency, generating the push rod parameters, and synchronously issuing control commands in step S400 of the present invention.

[0033] Figure 6 This is a comparison chart of the actual plant spacing error in the present invention.

[0034] Figure 7 This is a comparison diagram of the dynamic response of the seed metering motor to disturbances according to the present invention. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] See Figure 1 The present invention provides a synchronous control system for the sowing depth and plant spacing of an electric drive seeder, including a speed measuring radar, an attitude module, a force sensor, an angle sensor, a control unit, a depth adjustment push rod, and a seed metering execution assembly. The seed metering execution assembly includes a seed metering motor, a seed metering device driven by the seed metering motor, and a seed guide tube connected to the seed metering device.

[0037] The speed measuring radar establishes a signal connection with the control unit, the attitude module establishes a signal connection with the control unit, the force sensor establishes a signal connection with the control unit, the angle sensor establishes a signal connection with the control unit, the control unit establishes an electrical connection with the depth adjustment push rod, and the control unit establishes an electrical connection with the seeding motor of the seeding execution assembly.

[0038] The control unit integrates an acquisition module, a filtering module, a calculation module, a prediction module, a generation module, as well as pulse width modulation peripherals and digital-to-analog conversion peripherals. The acquisition module receives the oblique velocity output from the speed measuring radar, the pitch angle output from the attitude module, the raw pressure output from the force sensor, and the raw depth output from the angle sensor. The acquisition module transmits the oblique velocity, pitch angle, raw pressure, and raw depth to the filtering module. The filtering module performs a Kalman filter algorithm on the raw pressure and raw depth to generate filtered pressure and filtered depth.

[0039] The filtering module transmits the filtering pressure to the prediction module, and the filtering module transmits the filtering depth to the calculation module. The acquisition module transmits the oblique velocity and pitch angle to the calculation module. The calculation module reads the pitch angle and oblique velocity and performs spatial dimension reduction projection calculation to generate the horizontal velocity. The calculation module performs time derivative and filtering operation on the filtering depth to generate the vertical velocity and vertical acceleration. The prediction module calculates the chassis slip based on the difference between the filtering pressure and the foundation resistance threshold. The calculation module combines the vertical velocity and vertical acceleration to generate the time deviation.

[0040] The calculation module transmits the horizontal speed and time deviation to the generation module, and the prediction module transmits the chassis slip to the generation module. The generation module integrates the horizontal speed, chassis slip, and time deviation to perform orthogonal vector synthesis to generate the target frequency. The generation module integrates the filter pressure and horizontal speed to perform a fuzzy adaptive algorithm to generate push rod parameters. The generation module sends push rod control commands to the depth adjustment push rod and sends generator control commands to the seeding motor.

[0041] See Figure 2 Based on the above-mentioned synchronous control system for sowing depth and plant spacing of an electric-driven seeder, this invention also provides a method for synchronously controlling sowing depth and plant spacing of an electric-driven seeder, which includes the following steps: S100, the control unit controls the acquisition module to receive the oblique speed output by the speed measuring radar, the pitch angle output by the attitude module, the raw pressure output by the force sensor, and the raw depth output by the angle sensor, and controls the filtering module to perform Kalman filtering algorithm on the raw pressure and raw depth to generate filtered pressure and filtered depth. S200, the control unit controls the calculation module to read the pitch angle and oblique velocity, perform spatial dimension reduction projection calculation to generate the horizontal velocity, and controls the prediction module to calculate the chassis slip amount based on the difference between the filter pressure and the foundation resistance threshold; S300, the control unit controls the calculation module to perform time derivative and filtering operations on the filtering depth to generate vertical velocity and vertical acceleration, and combines the vertical velocity and vertical acceleration to generate time deviation; S400, the control unit controls the generation module to perform orthogonal vector synthesis calculations by fusing horizontal speed, chassis slip, and time deviation to generate the target frequency, and fusing filtered pressure and horizontal speed to perform fuzzy adaptive algorithms to generate push rod parameters, and sends push rod control commands to the depth adjustment push rod and generator control commands to the seeding motor.

[0042] The following provides a detailed explanation of the steps performed by the control unit.

[0043] See Figure 3 Step S100 includes the following sub-steps: S110, the control unit controls the acquisition module to establish a controller area network (SAR) bus communication interface. The acquisition module receives the yaw speed output from the speed measuring radar through the SAR bus communication interface. The acquisition module also receives the pitch angle output from the attitude module through the SAR bus communication interface.

[0044] For the data frame parsing process of the controller area network bus communication interface, those skilled in the art can refer to the standard communication protocol manual for software programming implementation. The data frame parsing process is a well-known technology in this field and will not be described in detail here.

[0045] S120, the acquisition module establishes the first analog input channel. The force sensor outputs a voltage signal. The acquisition module controls the first analog input channel to perform an analog-to-digital conversion operation on the voltage signal to generate a digital pressure signal. The acquisition module marks the digital pressure signal as the raw pressure and stores the raw pressure in an internal register.

[0046] S130, the acquisition module establishes a second analog input channel. The angle sensor outputs a current signal. The acquisition module controls the second analog input channel to perform an analog-to-digital conversion on the current signal to generate a digital depth signal. The acquisition module marks the digital depth signal as the raw depth and stores the raw depth in an internal register.

[0047] The S140 data acquisition module integrates a timer hardware circuit. The control unit controls this timer hardware circuit to generate a fixed-period interrupt signal. Based on this fixed-period interrupt signal, the acquisition module synchronously performs yaw rate reading, pitch angle reading, voltage signal analog-to-digital conversion, and current signal analog-to-digital conversion operations, ensuring that the yaw rate, pitch angle, initial pressure, and initial depth are aligned to an absolutely consistent timestamp node. The acquisition module then transmits the yaw rate, pitch angle, initial pressure, and initial depth, carrying the aligned timestamp nodes, to the filtering module.

[0048] S150, the field working environment contains high-frequency mechanical vibration. This high-frequency mechanical vibration injects white noise into the force and angle sensors. The original pressure and original depth readings are also mixed with white noise. This white noise disrupts the convergence state of the derivative calculation. The filtering module receives the original pressure and original depth readings transmitted by the acquisition module.

[0049] S160, the filtering module internally constructs a one-dimensional Kalman filter algorithm model. The filtering module defines the system state variables and observation variables. The filtering module sets the system noise covariance matrix and the measurement noise covariance matrix based on the frequency characteristics of high-frequency mechanical vibration.

[0050] S170, the filtering module applies a one-dimensional Kalman filter algorithm to the original pressure. The filtering module performs a time update operation based on the system noise covariance matrix to generate a prior state estimate and a prior error covariance matrix. The filtering module then performs a measurement update operation based on the measurement noise covariance matrix and the prior error covariance matrix to generate a Kalman gain. The filtering module combines the prior state estimate, the original pressure, and the Kalman gain to calculate a posterior state estimate for the original pressure. The filtering module marks the posterior state estimate for the original pressure as the filtered pressure and stores it in an internal register.

[0051] S180, the filtering module performs a one-dimensional Kalman filter algorithm on the original depth. The filtering module repeatedly performs time update operations and measurement update operations to calculate and generate a posterior state estimate for the original depth. The filtering module marks the posterior state estimate for the original depth as the filtered depth and stores the filtered depth in an internal register.

[0052] For the internal matrix recursive calculation process of the one-dimensional Kalman filter algorithm model, those skilled in the art can consult the digital signal processing manual for software programming implementation. The matrix recursive calculation process is a well-known technology in this field and will not be described in detail here.

[0053] See Figure 4 Step S200 includes the following sub-steps: The S210 speed-measuring radar is mounted on the chassis structure. During operation on slopes, the radar's detection direction is parallel to the slope trajectory, resulting in the output diagonal velocity having a slope vector component. The standard plant spacing is defined as the distance between adjacent seeds within a horizontal plane; directly using diagonal velocity introduces errors in plant spacing calculations. The calculation module receives the diagonal velocity and pitch angle transmitted by the acquisition module, carrying timestamps.

[0054] The S220's solution module integrates a floating-point arithmetic unit. The solution module inputs the pitch angle into the floating-point arithmetic unit to perform cosine mapping calculations to generate attitude compensation coefficients.

[0055] For the code implementation process of the floating-point arithmetic unit performing cosine mapping operations, those skilled in the art can refer to the microcontroller's underlying algorithm library for instruction calls. The code implementation process is a well-known technology in this field and will not be described in detail here.

[0056] S230, the solution module controls the floating-point arithmetic unit to perform a multiplication operation combining the oblique velocity and attitude compensation coefficient to generate the horizontal velocity, which is then stored in an internal register. The solution module performs the spatial dimension reduction projection calculation formula as follows: ; In the formula, Represents horizontal speed; Represents diagonal velocity; Represents the pitch angle.

[0057] S240, the depth adjustment push rod moves downward to increase the trenching depth. The soil generates traction resistance on the depth adjustment push rod. The increased traction resistance causes a momentary slippage of the chassis drive wheel. This momentary slippage causes a hysteresis error in the plant spacing control loop. The prediction module receives the filtered pressure carrying the timestamp node transmitted by the filtering module.

[0058] S250, the prediction module internally presets a basic resistance threshold. The prediction module controls the logic unit to read the filtered pressure obtained in the current sampling period. The prediction module controls the logic unit to calculate the difference between the filtered pressure and the basic resistance threshold, and marks the difference as effective additional resistance when the difference is greater than zero, and sets the effective additional resistance to zero when the difference is not greater than zero.

[0059] S260, the prediction module has a preset slip ratio coefficient. The prediction module's control logic unit multiplies the effective additional drag with the slip ratio coefficient to generate the chassis slip amount, which is then stored in an internal register. The chassis slip amount calculation formula executed by the prediction module is as follows: ; In the formula, Represents chassis slippage; Represents the slip ratio coefficient; Represents filter pressure; This represents the basic resistance threshold.

[0060] See Figure 4 Step S300 includes the following sub-steps: S310, the terrain undulation factor, combined with the downward movement of the depth-adjusting push rod, alters the absolute height of the seed metering device relative to the ground. This change in absolute height forces the seed metering device to produce a vertical displacement. This vertical displacement affects the seed's trajectory. The solution module receives the filtered depth, carrying timestamp nodes, transmitted from the filtering module.

[0061] The S320's solution module internally incorporates a numerical derivative. The solution module controls the numerical derivative to read the filter depth of the current sampling period and the filter depth of the previous sampling period. The solution module then controls the numerical derivative to calculate the difference between the current and previous sampling period filter depths. Based on the difference and the sampling time, the solution module performs a division operation to complete the first-order time derivative, generating the original vertical velocity. The solution module then performs a moving average filter on the original vertical velocity to generate a new vertical velocity, which is stored in an internal register.

[0062] S330, the solution module controls the numerical differentiater to read the vertical velocity of the current sampling period and the vertical velocity of the previous sampling period. The solution module controls the numerical differentiater to calculate the difference between the vertical velocity of the current sampling period and the vertical velocity of the previous sampling period. The solution module controls the numerical differentiater to perform a division operation based on the difference and the sampling time to complete the second-order time derivative operation and generate the original vertical acceleration. The solution module performs a moving average filter on the original vertical acceleration to generate the vertical acceleration, and the solution module stores the vertical acceleration in an internal register.

[0063] For the underlying logic of the numerical derivative performing difference calculations, those skilled in the art can refer to the digital control algorithm manual for software programming implementation. The underlying logic is a well-known technology in this field and will not be described in detail here.

[0064] S340, seeds inside the seed metering device detach from the seed metering disc and fall into the seed guide tube. The seed guide tube undergoes vertical displacement along with the seed metering device. This vertical displacement causes the inner wall of the seed guide tube to impact the seeds. This impact generates frictional resistance, which delays the seed's descent within the seed guide tube. This delay alters the seed's landing time. The calculation module reads the vertical velocity and vertical acceleration stored in its internal registers.

[0065] S350, the solution module internally presets the velocity friction coefficient and the acceleration friction coefficient. The solution module controls the floating-point arithmetic unit to perform a multiplication calculation between the vertical velocity and the velocity friction coefficient to generate the velocity deviation component. The solution module controls the floating-point arithmetic unit to perform a multiplication calculation between the vertical acceleration and the acceleration friction coefficient to generate the acceleration deviation component. The solution module controls the floating-point arithmetic unit to perform an addition calculation between the velocity deviation component and the acceleration deviation component to generate the time deviation. The solution module stores the time deviation in an internal register.

[0066] For the underlying instruction call mechanism of the floating-point arithmetic unit performing multiplication and addition calculations, those skilled in the art can refer to the microcontroller development manual for software programming implementation. The underlying instruction call mechanism is a well-known technology in this field and will not be described in detail here.

[0067] The formula for calculating the execution time deviation of the solution module is as follows: ; In the formula, Represents the time deviation; Represents the velocity coefficient of friction; Represents vertical velocity; Represents the coefficient of friction for acceleration; It represents vertical acceleration.

[0068] See Figure 5 Step S400 includes the following sub-steps: In S410, there is an inverse vector relationship between horizontal velocity and chassis slippage. Chassis slippage reduces the actual forward displacement speed of the seeder. Time deviation causes a longitudinal shift in the seeding landing position. This longitudinal shift disrupts the constant standard plant spacing. The generation module receives the horizontal velocity and time deviation, carrying timestamps, from the solution module. The generation module also receives the chassis slippage, carrying timestamps, from the prediction module.

[0069] The S420's generation module integrates a logic unit. The generation module controls this logic unit to read the horizontal speed and chassis slip. It then calculates the difference between the horizontal speed and chassis slip to generate a compensation speed. Finally, the generation module controls this logic unit to read the time deviation. Finally, it multiplies the compensation speed and the time deviation to generate the dynamic spacing compensation.

[0070] For the underlying logic of the logic unit performing numerical difference calculations, those skilled in the art can refer to the digital control algorithm manual for software programming implementation. The underlying logic is a well-known technology in this field and will not be described in detail here.

[0071] S430: The generation module has a preset standard plant spacing. The generation module's control logic unit adds the standard plant spacing and the dynamic spacing compensation amount to calculate the actual composite plant spacing. The generation module also has a preset minimum amplitude threshold. When the actual composite plant spacing is lower than the minimum amplitude threshold, the generation module's control logic unit forcibly clamps the actual composite plant spacing to the minimum amplitude threshold. The generation module's control logic unit then calculates the target frequency by dividing the compensation speed by the actual composite plant spacing.

[0072] The formula for the orthogonal vector composition operation performed by the generation module is as follows: ; In the formula, Represents the target frequency; Represents horizontal speed; Represents chassis slippage; Represents standard plant spacing; This represents the time deviation.

[0073] S440, soil resistance dynamically changes as the working equipment advances. Resistance fluctuations disrupt the original force balance of the depth-adjusting push rod. This change in force balance requires the depth-adjusting push rod to adjust its output pressure. The generation module receives filtered pressure carrying timestamp nodes from the filtering module. The generation module also receives horizontal velocity carrying timestamp nodes from the solution module. The generation module's internal memory stores preset pressure and velocity membership functions. The generation module inputs the filtered pressure into the pressure membership function and performs a mapping calculation to generate a pressure fuzzy vector. The generation module inputs the horizontal velocity into the velocity membership function and performs a mapping calculation to generate a velocity fuzzy vector. The generation module internally presets input universe intervals for the filtered pressure and horizontal velocity, and discretizes and maps these input universe intervals to each state node of the fuzzy rule control matrix.

[0074] For the code writing process of the generation module performing fuzzy calculations, those skilled in the art can refer to the basics of fuzzy control theory for software programming implementation. The code writing process is a well-known technology in this field and will not be described in detail here.

[0075] S450 generates a fuzzy rule control matrix that is burned into the internal memory of the generation module. The fuzzy rule control matrix defines the correspondence between the pressure fuzzy vector, the velocity fuzzy vector, and the output compensation weights.

[0076] The fuzzy rule control matrix follows the following configuration logic: when the pressure fuzzy vector represents an increase in filtering pressure and the velocity fuzzy vector represents an increase in horizontal velocity, it is determined that the dynamic impact resistance of the depth adjustment push rod increases significantly, and at this time the mapping value of the output compensation weight increases nonlinearly; when the pressure fuzzy vector represents a decrease in filtering pressure and the velocity fuzzy vector represents a decrease in horizontal velocity, it is determined that the force tends to be gentle, and at this time the mapping value of the output compensation weight decays and approaches the basic preset constant.

[0077] The generation module controls the logic arithmetic unit to traverse and query the fuzzy rule control matrix based on the pressure fuzzy vector and the velocity fuzzy vector, extract the matching rules, and generate a weighted fuzzy set.

[0078] The S460 generation module integrates a defuzzification operator. The generation module controls the defuzzification operator to perform centroid-based analytical calculations on the weighted fuzzy set to generate output compensation weights. The generation module also controls the defuzzification operator to read and store basic push-stick parameters from internal registers. Finally, the generation module controls the defuzzification operator to perform multiplication calculations between the output compensation weights and the basic push-stick parameters to generate push-stick parameters. These push-stick parameters are stored in internal registers.

[0079] The formula for calculating the push rod parameters in the generation module is as follows: ; In the formula, Represents the parameters of the push rod; Represents the output compensation weight; This represents the basic push rod parameters.

[0080] S470, the generator module's internal configuration instruction calculation unit. The generator module's control instruction calculation unit reads the target frequency and push rod parameters stored in its internal registers. To eliminate the transient cross-coupling interference caused by the change in the position of the individual mechanical structure of the depth-adjusting push rod during seeding depth adjustment on the load of the seeding motor, the instruction calculation unit introduces a cross-coupling compensation algorithm. The instruction calculation unit incorporates the push rod parameters as a real-time compensation term into the calculation process of the motor control instructions. The generator module executes the cross-coupling instruction calculation formula as follows: ; In the formula, This represents the duty cycle of the motor control commands; Represents the motor drive coefficient; Represents the target frequency; Represents the cross-coupling compensation coefficient; This represents the parameters of the push rod.

[0081] Simultaneously, the instruction calculation unit calculates the specific numerical value of the push rod control instruction based on the push rod parameters, namely the push rod control instruction voltage value, using the following formula: ; In the formula, This represents the voltage value of the push rod control command; This represents the gain coefficient of the push rod drive; This represents the parameters of the push rod.

[0082] The S480 generation module integrates a dual-channel direct memory access controller and a synchronous timer circuit. The control unit generates a hardware trigger strobe pulse through the synchronous timer circuit. The generation module controls the dual-channel direct memory access controller to respond to the hardware trigger strobe pulse, writing the motor control command duty cycle into the first pulse width modulation output register within the same system clock cycle, and simultaneously writing the push rod control command voltage value into the digital-to-analog converter output register, achieving hardware-level parallel alignment of control commands.

[0083] For the configuration of the dual-channel direct memory access controller and the underlying register configuration process of the synchronous timer circuit triggering mechanism, those skilled in the art can refer to the microcontroller chip datasheet to write the code. The underlying register configuration process is a well-known technology in this field and will not be described in detail here.

[0084] In S490, the first pulse width modulation (PWM) output register converts the duty cycle of the received motor control command into a corresponding PWM waveform and sends it to the seed metering motor. The seed metering motor responds to the PWM waveform and performs a synchronous adjustment of the plant spacing. The digital-to-analog converter (DAC) output register converts the push rod control command voltage value into a corresponding analog voltage signal and sends it to the depth adjustment push rod. The depth adjustment push rod responds to the analog voltage signal and performs a synchronous adjustment of the sowing depth. Since the seed metering motor and the depth adjustment push rod receive the corresponding control signals under the same hardware trigger node, the time delay caused by serial software transmission is eliminated, achieving synchronous control of sowing depth and plant spacing.

[0085] Specific application examples are as follows: This embodiment uses a certain type of electric precision seeder for soybean planting on hilly slopes (where there is slope and uneven soil hardness) as an application scenario. The seeder's seed metering assembly and depth adjustment push rod are controlled by the control unit.

[0086] During the specific sampling period of this embodiment, the seeder is operating on an uphill slope. The specific parameter acquisition and calculation process is as follows: The control unit controls the acquisition module to receive the diagonal speed output by the speed measuring radar through the controller local area network bus communication interface. The pitch angle output by the attitude module is 2.0 m / s. It is 10°.

[0087] The acquisition module synchronously acquires data, and the filtering module applies a one-dimensional Kalman filter algorithm to the original pressure and depth. During this sampling period, the acquired filtered pressure... The value is 1200N, and the filter depth indicates that the seed meter is experiencing vertical turbulence.

[0088] The solution module controls the numerical derivative to perform time differentiation and filtering operations based on the filtering depth, generating the vertical velocity. 0.5 m / s² and vertical acceleration 1.0 m / s 2 .

[0089] The solution module performs spatial dimension reduction projection calculations to generate horizontal velocity: ; The prediction module has a preset basic resistance threshold. 1000N, slip ratio coefficient The value is 0.001 (m / s) / N. Because the filter pressure (1200N) exceeds the basic resistance threshold (1000N), the effective additional resistance is 200N. The prediction module calculates and generates the chassis slippage: ; The calculation module has a preset velocity friction coefficient. The acceleration friction coefficient is 0.02 s / (m / s). 0.01s / (m / s) 2） The solution module calculates and generates the time deviation: ; The generation module has a preset standard plant spacing. The value is 0.20m. The generation module combines the above data and performs orthogonal vector synthesis to generate the target frequency: ; (Note: If the time deviation of slippage and bumping is not considered, the traditional target frequency calculation is only...) This invention suppresses frequency overshoot caused by environmental disturbances.

[0090] Simultaneously, the generation module integrates filtered pressure and horizontal velocity using a fuzzy adaptive algorithm. Under this condition, the pressure fuzzy vector represents increased force, while the velocity fuzzy vector represents normal velocity. The defuzzification unit calculates and generates output compensation weights. The value is 1.2. This is based on the basic push rod parameters. Set the value to 50, and generate the follower parameters: ; The generation module has an internal configuration instruction calculation unit that presets the motor drive coefficients. The cross-coupling compensation coefficient is 5.0. The gain coefficient of the push rod drive is 0.1. It is 0.2.

[0091] The instruction calculation unit incorporates push rod parameters as compensation terms to generate the motor control instruction duty cycle: ; Generate the voltage value for the actuator control command: ; Finally, the control unit triggers the dual-channel direct memory access controller via a synchronous timer circuit, and... (43.6%) and (12.0V) Write to the first pulse width modulation output register and the digital-to-analog converter output register respectively within the same system clock cycle to achieve hardware-level synchronous output.

[0092] The experimental verification and effect comparison are as follows: To verify the engineering effectiveness of the synchronous control system and method for seeding depth and plant spacing of the electric-driven seeder provided by this invention, comparative tests were conducted in the same sloping experimental field. The control group used a traditional control system (without calculating chassis slippage and time deviation, and control commands were issued serially via software), while the experimental group used the system of this invention. At the 2nd second of system operation, the machine entered a hard soil area where soil compaction abruptly changed, causing a sudden increase in soil resistance and high-frequency mechanical vibration.

[0093] See Figure 6 ,from Figure 6 As can be seen, after the sudden change in soil resistance at the 2nd second, the traditional control system did not include the chassis slippage and time deviation in the calculation, resulting in damage to the actual forward displacement of the seeder and a delay in the seed falling trajectory. As a result, the actual synthetic plant spacing showed a deviation of up to 18 mm.

[0094] The system of this invention integrates horizontal speed, chassis slip, and time deviation into an orthogonal vector synthesis operation in its generation module, thereby correcting the target frequency in real time. The plant spacing error is contained within a small fluctuation range of ±3 mm, ensuring the constant state of the standard plant spacing.

[0095] See Figure 7 ,from Figure 7 As can be seen, when encountering dynamic impact resistance requiring the depth adjustment push rod to adjust the output pressure, the traditional control system exhibits obvious serial hysteresis, and the motor control command fails to detect the load change caused by the push rod movement.

[0096] The system of this invention introduces a cross-coupling compensation algorithm (using the push rod parameter as a real-time compensation item) in the instruction calculation unit, and achieves hardware-level parallel alignment through a dual-channel direct memory access controller and a synchronous timer circuit. The motor control instruction duty cycle immediately outputs a compensation pulse at the instant of the sudden change in resistance (the 2nd second), eliminating the transient cross-coupling interference caused by the change in the position of the individual mechanical structure on the load of the seeding motor.

Claims

1. A synchronous control system for sowing depth and plant spacing in an electric-driven seeder, characterized in that, Includes control unit, speed radar, attitude module, force sensor, angle sensor, depth adjustment push rod and seeding actuator assembly; The seed metering assembly includes a seed metering motor, a seed meterer, and a seed guide tube; The speed measuring radar, the attitude module, the force sensor, and the angle sensor are all signal-connected to the control unit; The control unit integrates an acquisition module, a filtering module, a calculation module, a prediction module, a generation module, a synchronous timer circuit, a dual-channel direct memory access controller, a first pulse width modulation output register, and a digital-to-analog conversion output register. The synchronous timer circuit is used to generate hardware trigger strobe pulses; The dual-channel direct memory access controller is used to respond to the hardware trigger strobe pulse and write in parallel to the first pulse width modulation output register and the digital-to-analog converter output register; The first pulse width modulation output register is electrically connected to the seeding motor, and the digital-to-analog converter output register is electrically connected to the depth adjustment push rod.

2. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 1, characterized in that, The acquisition module is used to receive the oblique velocity output by the speed measuring radar and the pitch angle output by the attitude module, and to establish a first analog input channel and a second analog input channel. The first analog input channel is used to perform analog-to-digital conversion on the voltage signal output by the force sensor to generate the raw pressure; The second analog input channel is used to perform the analog-to-digital conversion on the current signal output by the angle sensor to generate the original depth; The acquisition module is used to synchronously complete data reading and analog-to-digital conversion according to a fixed-period interrupt signal, and transmit the original pressure and original depth to the filtering module, and transmit the oblique velocity and pitch angle to the calculation module.

3. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 2, characterized in that, The filtering module is used to internally construct a one-dimensional Kalman filter algorithm model, which is used to define system state variables and observation variables, and set the system noise covariance matrix and measurement noise covariance matrix. The filtering module is used to perform time update operations and measurement update operations on the original pressure, generate a posterior state estimate for the original pressure, and mark the posterior state estimate for the original pressure as the filtered pressure. The filtering module is further configured to perform the time update operation and the measurement update operation on the original depth, generate a posterior state estimate for the original depth, and mark the posterior state estimate for the original depth as the filtered depth.

4. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 3, characterized in that, The calculation module integrates a floating-point arithmetic unit, which is used to generate attitude compensation coefficients based on the pitch angle. The calculation module is used to generate horizontal velocity based on the oblique velocity and the attitude compensation coefficients. The prediction module has a preset basic resistance threshold and a slip ratio coefficient. The prediction module is used to generate chassis slip amount based on the filter pressure, the basic resistance threshold and the slip ratio coefficient.

5. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 4, characterized in that, The solution module is equipped with a numerical derivative. The numerical derivative is used to perform a first-order time derivative operation on the filtering depth, and the solution module is used to perform a moving average filter on the result of the first-order time derivative operation to generate a vertical velocity. The numerical derivative is further used to perform a second-order time derivative operation on the vertical velocity, and the solution module is further used to perform the moving average filtering on the result of the second-order time derivative operation to generate vertical acceleration.

6. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 5, characterized in that, The calculation module has preset velocity friction coefficient and acceleration friction coefficient; The calculation module is used to generate a velocity deviation component based on the vertical velocity and the velocity friction coefficient, generate an acceleration deviation component based on the vertical acceleration and the acceleration friction coefficient, and generate a time deviation based on the velocity deviation component and the acceleration deviation component.

7. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 6, characterized in that, The generation module is used to generate a compensation speed based on the horizontal speed and the chassis slip, and to generate a dynamic spacing compensation amount based on the compensation speed and the time deviation. The generation module has a preset standard plant spacing and a minimum amplitude threshold. The generation module is also used to generate an actual synthetic plant spacing based on the standard plant spacing and the dynamic spacing compensation amount, and to force the actual synthetic plant spacing to be clamped to the minimum amplitude threshold when the actual synthetic plant spacing is lower than the minimum amplitude threshold. The generation module is also used to generate a target frequency based on the compensation speed and the actual synthetic plant spacing.

8. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 7, characterized in that, The generation module internally presets a pressure membership function, a velocity membership function, and a fuzzy rule control matrix; The generation module is used to generate a pressure fuzzy vector based on the filtered pressure and the pressure membership function, and to generate a velocity fuzzy vector based on the horizontal velocity and the velocity membership function. The generation module is further configured to generate a weighted fuzzy set based on the pressure fuzzy vector, the velocity fuzzy vector and the fuzzy rule control matrix, and to perform centroid analysis on the weighted fuzzy set to generate output compensation weights.

9. The synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 8, characterized in that, The generation module is used to read the basic push rod parameters stored in the internal register; The generation module is also used to generate push rod parameters based on the output compensation weight and the basic push rod parameters, and store the push rod parameters in the internal register.

10. A synchronous control system for sowing depth and plant spacing of an electric-driven seeder according to claim 9, characterized in that, The generation module is configured with an instruction calculation unit, which is used to generate a motor control instruction duty cycle based on the target frequency and the push rod parameters, and to generate a push rod control instruction voltage value based on the push rod parameters. The dual-channel direct memory access controller is used to respond to the hardware trigger strobe pulse, write the duty cycle of the motor control command into the first pulse width modulation output register within the same system clock cycle, and write the voltage value of the push rod control command into the digital-to-analog converter output register.

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