Peanut sowing depth control method based on single air spring-electric cylinder coupling

Abstract

The present application relates to the technical field of peanut seeding, and particularly relates to a sowing depth control method based on peanut seeding single air spring-electric cylinder coupling. The method comprises the following steps: signal processing and conversion into digital electrical signals; obtaining sowing depth error and its change trend; identifying the working condition of the current operation state; calculating an air spring-electric cylinder collaborative distribution coefficient, and generating an air spring target pressure and an electric cylinder target displacement according to the collaborative distribution coefficient; coupling dynamic correction of the air spring target pressure and the electric cylinder target displacement; when the missing sowing state quantity or the missing sowing rate exceeds a set threshold value, performing secondary linkage correction on the air spring-electric cylinder collaborative distribution coefficient, the first corrected air spring target pressure and the first corrected electric cylinder target displacement. The method can timely correct the sowing depth control parameters, and improve the profiling capability and sowing depth consistency under complex terrain conditions.

Description

Technical Field

[0001] This invention relates to the field of electrical signal processing technology in peanut planting process, and in particular to a method for controlling planting depth based on the coupling of a peanut planting unit air spring and electric cylinder. Background Technology

[0002] Peanut planting operations require high standards for consistent planting depth, stable planting posture, and quality of soil covering and compaction. Especially in hilly areas, uneven ridge surfaces, and areas with varying soil density, the furrow opener is easily affected by changes in ground contour and impact loads during operation, resulting in vertical fluctuations and posture deviations. This leads to problems such as unstable planting depth, missed planting, shallow planting, deep planting, and uneven emergence, affecting the quality of peanut plant establishment and subsequent yield formation.

[0003] Existing seeder contouring mechanisms mostly employ passive structures such as depth-limiting wheels, compression springs, and parallelogram contouring frames. These mechanisms primarily rely on ground reaction forces and the deformation of the elastic elements themselves to achieve following adjustment. While the structure is relatively simple, it still has the following shortcomings under complex terrain and high operating speed conditions:

[0004] (1) The response to ground-level sudden changes is mainly passive following, with a certain adjustment lag, making it difficult to balance rapid following and stable control;

[0005] (2) Ordinary mechanical springs have limited buffering capacity and are prone to directly transmitting vibration to the furrow opener under impact, affecting the stability of furrowing and seeding.

[0006] (3) It is difficult to achieve accurate compensation of the furrow opener position by simply relying on mechanical elastic elements, and it is difficult to meet the requirements of precision sowing for consistent sowing depth;

[0007] (4) Existing contouring mechanisms generally lack active adjustment functions based on sensor detection, making it difficult to meet the planting requirements of crops such as peanuts, and also difficult to adapt to the sowing needs of hilly and mountainous areas, ridge cultivation conditions and complex surface environments. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned defects in the existing technology and propose a seeding depth control method based on peanut seeding unit air spring-electric cylinder coupling, which can promptly correct seeding depth control parameters and improve the contour-following ability and seeding depth consistency under complex terrain conditions.

[0009] The technical solution of this invention is: a method for controlling the sowing depth of peanuts based on a single air spring-electric cylinder coupling, comprising the following steps:

[0010] S1. Use sensors to collect signals during the peanut planting process, and process and convert the signals into digital electrical signals;

[0011] S2. Calculate the current seeding depth estimate based on the data in step S1, and compare it with the target seeding depth to obtain the seeding depth error and its changing trend.

[0012] S3. Identify the current operating status;

[0013] S4. When the current working state is the coordinated adjustment condition, calculate the air spring-electric cylinder coordinated distribution coefficient, and generate the air spring target pressure and electric cylinder target displacement based on the coordinated distribution coefficient.

[0014] S5. Couple the air spring target pressure and electric cylinder target displacement for dynamic correction to obtain the first corrected air spring target pressure and the first corrected electric cylinder target position.

[0015] S6. When the missed seeding status or missed seeding rate exceeds the set threshold, a missed seeding linkage correction amount is constructed based on the current missed seeding status and its change amount. Based on step S5, a second linkage correction is performed on the air spring-electric cylinder cooperative distribution coefficient, the air spring target pressure after the first correction, and the electric cylinder target displacement after the first correction.

[0016] In this invention, the upper end of the electric cylinder assembly is connected to the top of the frame assembly, and its lower end is connected to the air spring assembly through a connecting mechanism; the lower end of the air spring assembly is connected to the contour connecting mechanism.

[0017] The contour-following connection mechanism includes:

[0018] Two front hinge shafts are arranged horizontally and are parallel to each other. Both front hinge shafts are hinged to the frame assembly.

[0019] Two rear hinge shafts are respectively arranged in a corresponding manner to two front hinge shafts. The rear hinge shafts and the front hinge shafts are parallel to each other. The ends of the rear hinge shafts are connected to the ends of the corresponding front hinge shafts by connecting rods. The rear hinge shafts are hinged to the air spring assembly.

[0020] The rear profile support and the end of the rear hinge shaft are respectively hinged to the rear profile support, and the rear profile support is connected to the trenching mechanism.

[0021] Trenching equipment includes:

[0022] Two symmetrically arranged trenchers;

[0023] The furrow opener support rod has its upper end fixedly connected to the furrow opener mounting frame and its lower end connected to the furrow opener.

[0024] The trencher mounting bracket has trencher mounting brackets fixed on both sides of the rear contour bracket.

[0025] In step S1, a laser rangefinder sensor is used to collect the displacement signal of the furrow opener mounting frame relative to the frame assembly, an angle sensor is used to collect the attitude signal of the seeding unit, a pressure sensor is used to collect the pressure signal of the air spring assembly, and a photoelectric sensor is used to collect the missed seeding status signal during the seeding process.

[0026] Analog voltage signal output by laser rangefinder The converted value is a digital quantity. Its expression is:

[0027] ,

[0028] in, This is the reference voltage for analog-to-digital conversion. For the number of bits in the analog-to-digital conversion, The range of the laser rangefinder sensor.

[0029] Pitch angle analog voltage signal output by angle sensor and roll angle analog voltage signal After conversion, the pitch angle digital value is obtained. and roll angle digital quantity :

[0030] ,

[0031] in, The analog-to-digital conversion reference voltage for the pitch angle; The number of bits for the analog-to-digital conversion; The attitude range for pitch angle; The analog-to-digital conversion reference voltage for roll angle; The attitude range for the roll angle;

[0032] Displacement value After calibration and conversion, it is:

[0033] ,

[0034] ,

[0035] ,

[0036] in, This represents the pitch angle displacement value; This is the roll angle displacement value; For displacement calibration coefficients; This refers to the pitch angle displacement calibration coefficient; This is the roll angle displacement calibration coefficient; This is the zero-point compensation amount for the pitch angle; This is the zero-point compensation amount for the roll angle.

[0037] In step S2, the target depth is used for seeding. Based on the displacement value Calculate the current seeding depth estimate :

[0038] ,

[0039] in, For seeding depth error;

[0040] ,

[0041] in, The baseline seeding depth is set.

[0042] In step S3,

[0043] Within the preset short-time window, when the absolute value of the seeding depth error is less than And the absolute values ​​of the attitude deviations are all less than When the seeding depth error rate is greater than a certain value, it is considered a small disturbance state; when the seeding depth error rate is greater than a certain value, it is considered a small disturbance state. The rate of change of attitude is greater than Or the rate of change of air spring pressure is greater than When a high-frequency disturbance is detected, the air spring assembly plays a dominant role.

[0044] Within a preset long-term window, when the absolute value of the seeding depth error continuously exceeds [a certain value]... The average seeding depth error consistently exceeds Or the average attitude deviation consistently exceeds The condition is determined to be a low-frequency large disturbance or a cumulative seeding depth deviation state, and is identified as an active compensation condition, in which case the electric cylinder assembly plays a leading role.

[0045] When the rate of change of seeding depth error is greater than within the short-time window The rate of change of attitude is greater than Or the rate of change of air spring pressure is greater than At the same time, the rate of change reaches 1.5 to 3 times the average rate of change within the short time window; and within the preset long time window, the duration for which the seeding depth error or attitude deviation continuously exceeds the corresponding allowable range reaches 50% to 80% of the long time window, or the number of sampling points exceeding the limit accounts for 50% to 80% of the total number of sampling points in the long time window, which is identified as a coordinated adjustment condition.

[0046] In step S4, let the air spring-electric cylinder cooperative distribution coefficient be... ,and :

[0047] ,

[0048] in, This represents the rate of change of seeding depth error. This is for attitude deviation; This is a missed broadcast status variable; This refers to the actual pressure of the air spring. This refers to the upper limit of the allowable pressure for the air spring. This represents the remaining stroke of the electric cylinder. This is the maximum stroke of the electric cylinder; The distribution coefficient for the rate of change of seeding depth error. The distribution coefficient for attitude deviation. The allocation coefficient for the missed broadcast status quantity. This is the distribution coefficient for the air spring pressure state. This is the distribution coefficient for the remaining stroke state of the electric cylinder, and ;

[0049] Based on the collaborative allocation coefficient Generate target displacement of electric cylinder :

[0050] ,

[0051] in, This is the basic displacement compensation amount generated based on the seeding depth error; This is the attitude deviation correction coefficient; This is a correction factor for missed broadcasts. This is the correction factor for the air spring support margin;

[0052] Based on the collaborative allocation coefficient Generate air spring target pressure :

[0053] ,

[0054] in, To provide basic support against pressure; This is an indicator of disturbance intensity. The current position of the electric cylinder; This is the maximum stroke of the electric cylinder; This is the terrain disturbance correction factor; This is a correction factor for the forming state of the electric cylinder; This is a pressure correction factor for missed broadcast conditions. .

[0055] In step S5,

[0056] When the attitude deviation increases or the current pressure of the air spring is lower than its allowable upper limit, an additional dynamic correction is applied to the target displacement of the electric cylinder in step S4. The dynamically corrected target displacement of the electric cylinder is:

[0057] ,

[0058] in, This represents the target displacement of the electric cylinder after the first correction. This refers to the attitude deviation correction coefficient during the dynamic correction process; This is the correction coefficient for the missed broadcast status during the dynamic correction process; This is the correction coefficient for the air spring support margin during the dynamic correction process.

[0059] When the attitude deviation increases or the current position of the electric cylinder approaches its maximum stroke, the target pressure of the air spring in step S4 is dynamically corrected. The dynamically corrected target pressure of the air spring is:

[0060] ,

[0061] in, The target pressure for the air spring after the first correction; This refers to the terrain disturbance correction factor during the dynamic correction process; This is the correction coefficient for the electric cylinder forming state during the dynamic correction process; This is the pressure correction coefficient for the missed broadcast status during the dynamic correction process.

[0062] In step S6,

[0063] Let the theoretical number of times the seed passes through within a unit sampling window be . The actual number of tests was The missed broadcast rate It can be represented as:

[0064] ,

[0065] When the missed broadcast rate exceeds the set threshold, step S6 is initiated.

[0066] Missed broadcast linkage correction amount for:

[0067] ,

[0068] in, This is used to characterize the degree of influence of the current missed broadcast status on the missed broadcast linkage correction amount. Used to characterize the degree of influence of changes in the missed seeding status quantity on the missed seeding linkage correction quantity. ;

[0069] This represents the change value of the missed broadcast status.

[0070] = - ,

[0071] in, This represents the missed broadcast status from the previous moment or the previous statistical window.

[0072] Based on the missed broadcast correction amount, the collaborative allocation coefficient is corrected to obtain the corrected collaborative allocation coefficient. for:

[0073] ,

[0074] in, The collaborative allocation correction coefficient is used to characterize the degree of influence of the missed broadcast linkage correction amount on the final collaborative allocation coefficient.

[0075] For the corrected collaborative allocation coefficient Perform amplitude limiting to meet the following requirements:

[0076] ,

[0077] Based on the corrected cooperative allocation coefficient The target displacement of the electric cylinder after the first correction After redistribution correction, the final target displacement of the electric cylinder is obtained. :

[0078] ,

[0079] in, This is a displacement correction coefficient, used to characterize the degree of influence of the missed-broadcast linkage correction on the final target displacement of the electric cylinder.

[0080] Based on the modified cooperative allocation coefficient The target displacement of the electric cylinder after the first correction After redistribution correction, the final target displacement of the electric cylinder is obtained. :

[0081] ,

[0082] in, This is the pressure correction coefficient, used to characterize the degree of influence of the missed broadcast linkage correction on the final target pressure of the air spring;

[0083] Based on the final target spring pressure It controls the intake or exhaust valve to adjust the internal pressure and support stiffness of the air spring assembly; simultaneously, it adjusts the final target displacement of the electric cylinder. Output displacement compensation commands to control the extension and retraction of the electric cylinder assembly to adjust the position of the trencher mounting frame.

[0084] The air spring assembly includes:

[0085] The elastic airbag is equipped with a pressure sensor and an air source interface. An air intake valve and an air exhaust valve are connected between the air source interface and the elastic airbag.

[0086] Upper mounting base: The upper end of the elastic airbag is provided with an upper mounting base;

[0087] The lower mounting base is provided at the lower end of the elastic airbag.

[0088] The electric cylinder assembly includes a telescopic rod, which is disposed inside the cylinder body;

[0089] The upper end of the telescopic rod is connected to the output shaft of the reduction mechanism, and the output end of the drive motor is connected to the reduction mechanism;

[0090] The lower end of the telescopic rod is connected to the air spring assembly via a connecting mechanism.

[0091] The beneficial effects of this invention are:

[0092] (1) By connecting the air spring assembly and the electric cylinder assembly in series along the adjustment direction of the seeding unit, and by having the controller couple the target quantity generation and the execution state of the two to correct each other, the buffering and vibration reduction and displacement compensation are achieved in the same closed loop, thus avoiding the control conflict and response lag caused by simple parallel control.

[0093] (2) Through multi-source collaborative sensing of displacement, attitude, pressure and missed seeding, the working status of furrow opener and seed meterer can be more accurately characterized, improving the accuracy of seeding depth estimation and the ability to identify working conditions.

[0094] (3) By allocating the action of air springs and electric cylinders according to the type of disturbance, the buffering effect of air springs can be given priority under high-frequency impact disturbances, and the active compensation effect of electric cylinders can be given priority under low-frequency large deviations, thereby improving the conformity and consistency of seeding depth under complex terrain conditions.

[0095] (4) By adjusting the missed sowing detection linkage, the sowing depth control parameters or operation status can be corrected in time when sowing abnormalities occur, thereby improving the reliability of sowing and the level of intelligent operation. Attached Figure Description

[0096] Figure 1 This is a flowchart of the control method of the present invention described in this application;

[0097] Figure 2 This is a schematic diagram of the overall structure of the air spring-electric cylinder coordinated active contouring depth adjustment mechanism for the peanut planter described in this application;

[0098] Figure 3 This is a schematic diagram showing the air spring assembly and electric cylinder assembly connected in series as described in this application;

[0099] Figure 4This is a schematic diagram of the structure of the air spring-electric cylinder cooperative active contouring depth adjustment mechanism described in this application;

[0100] Figure 5 This is a schematic diagram of the arrangement of the missed broadcast detection unit described in this application;

[0101] Figure 6 This is a schematic diagram showing the arrangement of the displacement detection unit and attitude detection unit described in this application.

[0102] In the diagram: 1. Frame assembly; 12. Electric cylinder connecting beam; 13. Seed box; 14. Seed metering device; 2. Contouring connection mechanism; 3. Furrowing mechanism; 31. Furrow opener; 32. Furrow opener mounting bracket; 4. Air spring assembly; 41. Upper mounting base; 42. Lower mounting base; 43. Elastic airbag; 44. Air pressure sensor; 45. Air source interface; 5. Electric cylinder assembly; 51. Drive motor; 52. Reduction mechanism; 53. Cylinder body; 54. Telescopic rod; 55. Pull wire sensor; 6. Connecting mechanism; 7. Photoelectric sensor; 8. Angle sensor; 9. Laser rangefinder sensor. Detailed Implementation

[0103] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0104] Specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0105] This application proposes a method for controlling the seeding depth based on the air spring-electric cylinder coupling of a peanut planter, the flowchart of which is shown below. Figure 1 As shown. The method includes the following steps.

[0106] The first step involves using a displacement detection unit (laser range sensor 9) to collect displacement signals of the furrow opener mounting frame 32 relative to the frame assembly 1, an attitude detection unit (angle sensor 8) to collect attitude signals, a pressure detection unit (air pressure sensor 44) to collect pressure signals of the air spring assembly, and a missed seed detection unit (photoelectric sensor 14) to collect missed seed status signals during the seeding process. All signals are then transmitted to the control mechanism.

[0107] The control mechanism performs analog-to-digital conversion, decoding, filtering, time synchronization, and state fusion processing on the collected signals to obtain corresponding displacement data, attitude data, pressure data, omission data, and electric cylinder position status data.

[0108] like Figure 2As shown, the peanut planter unit described in this application includes a frame assembly 1, a contour connecting mechanism 2, a furrowing mechanism 3, an air spring assembly 4, and an electric cylinder assembly 5. The contour connecting mechanism 2 adopts a four-bar contouring mechanism, with its front end hinged to the frame assembly 1 and its rear end connected to the furrowing mechanism 3.

[0109] Meanwhile, an air spring assembly 4 and an electric cylinder assembly 5 are provided between the rear end of the contour connecting mechanism 2 and the top end of the frame assembly 1. The electric cylinder assembly 5 is located above the air spring assembly 4. To prevent misalignment between the electric cylinder assembly 5 and the air spring assembly 4 during movement, the electric cylinder assembly 5 and the air spring assembly 4 are connected by a connecting mechanism 6. One end of the electric cylinder assembly 5 and the air spring assembly 4 is inserted into the connecting mechanism 6, which is cylindrical. In this embodiment, the connecting mechanism 6 and the lower end of the electric cylinder assembly 5, and the connecting mechanism 6 and the upper mounting base of the air spring assembly 4 are connected in series by welding, respectively, to restrict the degrees of freedom of the electric cylinder assembly 5 and the air spring assembly 4, allowing them to move linearly.

[0110] During the operation of the electric cylinder assembly 5 and the air spring assembly 4, the contouring connection mechanism 2 is driven to undergo contouring deformation, which in turn drives the trenching mechanism 3 to move up and down relative to the frame assembly 1.

[0111] like Figure 4 As shown, the trenching mechanism 3 includes two trenchers 31 arranged in pairs, symmetrically positioned. Each trencher 31 is connected to the bottom of a trencher support rod, which is vertically oriented. The upper part of the support rod is connected to the rear end of the contour-following connecting mechanism 2. In this embodiment, the upper end of the support rod is fixedly connected to a trencher mounting frame 32, which is connected to the rear end of the contour-following connecting mechanism 2. As the mounting frame 32 moves up and down with the contour-following connecting mechanism 2, the support rod drives the trenchers 31 to move up and down, achieving the vertical movement of the trenchers 31 and ensuring the stability of their working posture.

[0112] The contouring connection mechanism 2 includes two front hinge shafts at the front and two rear hinge shafts at the rear. The two front hinge shafts are arranged horizontally and parallel to each other, while the two rear hinge shafts are arranged correspondingly to the two front hinge shafts. The front hinge shafts are hinged to the frame assembly 1, and the two ends of the two rear hinge shafts are respectively hinged to the two ends of the corresponding front hinge shafts via connecting rods. Simultaneously, the rear hinge shafts are hinged to the rear contouring bracket, with both ends of the rear hinge shafts hinged to the rear contouring bracket. The rear contouring bracket is hinged to the frame assembly 1 via the rear hinge shafts and connecting rods. Ditcher mounting brackets 32 are fixedly connected to both sides of the rear contouring bracket.

[0113] The bottom end of the air spring assembly 4 is hinged to the rear hinge shaft. When the electric cylinder assembly 5 and the air spring assembly 4 are activated, the rear hinge shaft drives the rear contour bracket to make a circular motion around the front hinge shaft via the connecting rod. At this time, the contour bracket drives the trencher 31 to achieve up and down lifting and lowering through the trencher mounting bracket 32.

[0114] The air spring assembly 4 and the electric cylinder assembly 5 are connected in series via a connecting device 6 between the electric cylinder connecting beam 12 and the trenching mechanism 3 at the top of the frame assembly 1. Figure 3 As shown, the air spring assembly 4 includes an upper mounting base 41, a lower mounting base 42, an elastic airbag 43, a pressure sensor 44, and an air source interface 45. The upper mounting base 41 is located at the upper end of the elastic airbag 43, and the lower mounting base 42 is located at the lower end of the elastic airbag 43. The pressure sensor 44 and the air source interface 45 are located at the elastic airbag 43. Gas is injected into or released from the elastic airbag 43 through the air source interface 45, and the pressure sensor 44 monitors the air pressure inside the elastic airbag 43 in real time. The air spring assembly 4 is used to withstand static loads, absorb shocks, and adjust the support characteristics by changing the air pressure inside the elastic airbag.

[0115] The electric cylinder assembly 5 includes a drive motor 51, a reduction mechanism 52, a cylinder body 53, a telescopic rod 54, and a pull-wire sensor 55. It is used to drive the trenching mechanism 3 to generate active displacement compensation according to the displacement compensation command output by the controller. The upper end of the telescopic rod 54 is connected to the reduction mechanism 52, and the lower end of the telescopic rod 54 is connected to the air spring assembly 4 through a connecting mechanism 6. The output end of the drive motor 51 is equipped with a reduction mechanism 52, which reduces the output shaft of the drive motor 51. The output shaft of the reduction mechanism 52, through a lead screw and nut pair set in the cylinder body 53, realizes the reciprocating linear motion of the telescopic rod 54. During the extension and retraction of the telescopic rod 54, the trencher 31 moves up and down through the air spring assembly 4 and the contour connecting mechanism 2. The pull-wire sensor 55 can accurately sense and provide feedback on the extension and retraction length of the telescopic rod 54, thereby achieving precise control of the extension and retraction length of the telescopic rod 54. The electric cylinder assembly 5 in this application is used to drive the trenching mechanism 3 to generate active displacement compensation according to the displacement compensation command output by the controller.

[0116] like Figure 5 As shown, a seed box 13 is mounted on the frame assembly 1 above the furrowing mechanism 3, and a seed metering device 14 is positioned between the seed box 13 and the furrowing mechanism 3. A photoelectric sensor 7 is installed at the seed outlet position of the seed metering device 14. The photoelectric sensor 7 is used to detect the number of times seeds pass through per unit time or the time interval between the passage of two adjacent seed types to determine the missed seeding status. Figure 6As shown, a laser rangefinder sensor 9 is installed on the frame assembly 1 and the furrow opener mounting frame 32. The laser rangefinder sensor 9 is used to detect the real-time displacement of the furrow opener mounting frame 32 relative to the frame assembly 1. An angle sensor 8 is installed on the electric cylinder connecting beam 12. The angle sensor 8 is used to detect changes in the pitch angle, roll angle, or tilt angle of the frame assembly 1 and the seeding unit.

[0117] The device also includes a control mechanism, which is electrically connected to the air spring assembly 4, the electric cylinder assembly 5, the photoelectric sensor 7, the angle sensor 8, and the laser rangefinder 9. The control mechanism acquires, converts, filters, and synchronizes the signals from each sensor with the time, and calculates the estimated seeding depth based on the displacement and attitude data to improve the accuracy of the seeding depth estimation.

[0118] To achieve quantization of various detection signals, the output signals of multiple sensors in the control mechanism are converted and calculated.

[0119] When the displacement detection unit, i.e., the laser rangefinder sensor 9, outputs an analog voltage signal At that time, the control mechanism obtains a digital quantity after analog-to-digital conversion. Its expression is:

[0120] ,

[0121] in, This is the reference voltage for analog-to-digital conversion. For the number of bits in the analog-to-digital conversion, This refers to the range of the laser rangefinder sensor.

[0122] When the angle sensor uses an inertial measurement unit, the estimated values ​​of the attitude angles, including pitch and roll angles, can be obtained from the acceleration components; the control mechanism combines the integral results of the angular velocity to perform a fusion calculation to obtain the pitch angle. and roll angle The real-time estimated value is used to characterize the attitude changes of the whole machine and individual seeding units.

[0123] When the attitude detection unit, i.e., the angle sensor 8, outputs an analog voltage signal of the pitch angle... Analog voltage signal of roll angle At that time, the control mechanism obtains the digital value of the pitch angle after analog-to-digital conversion. and the digital quantity of roll angle Its expression is:

[0124] ,

[0125] in, The analog-to-digital conversion reference voltage for the pitch angle; The number of bits for the analog-to-digital conversion; The attitude range for pitch angle; The analog-to-digital conversion reference voltage for roll angle; The attitude range for the roll angle.

[0126] Displacement value It can be converted to the following after calibration:

[0127] ,

[0128] ,

[0129] ,

[0130] in, This represents the pitch angle displacement value; This is the roll angle displacement value; For displacement calibration coefficients; This refers to the pitch angle displacement calibration coefficient; This is the roll angle displacement calibration coefficient; This is the zero-point compensation amount for the pitch angle; This is the zero-point compensation amount for the roll angle.

[0131] The second step is to calculate the current seeding depth estimate based on displacement and attitude data, and compare it with the target seeding depth to obtain the seeding depth error and its changing trend.

[0132] The control mechanism aims to achieve the desired depth. Based on the displacement value Calculate the current seeding depth estimate The seeding depth error is:

[0133] ,

[0134] in, For seeding depth error;

[0135] ,

[0136] in, The baseline seeding depth is set.

[0137] The third step is to identify the current operating status.

[0138] In this application, based on the seeding depth error Seeding depth error change rate Posture deviation Attitude change rate, actual air spring pressure Air spring pressure change rate Current position of electric cylinder and the remaining itinerary It identifies the current working status.

[0139] Within a preset short-time window, when both the absolute value of the seeding depth error and the absolute value of the attitude deviation are less than the corresponding small-amplitude threshold, it is determined to be a small-amplitude disturbance state; wherein, the seeding depth error small-amplitude threshold is preferably... The preferred threshold for small attitude deviation is... A high-frequency disturbance is determined to exist when at least one of the seeding depth error change rate, attitude change rate, or air spring pressure change rate exceeds the corresponding high-frequency threshold; wherein, the high-frequency threshold for the seeding depth error change rate is preferably... The preferred high-frequency threshold for attitude change rate is... The preferred high-frequency threshold for the air spring pressure change rate is... At this time, the air spring assembly 4 plays a dominant role.

[0140] Within a preset long-term window, when the absolute value of the seeding depth error continuously exceeds the seeding depth deviation threshold, or when at least one of the average seeding depth error or the average attitude deviation continuously exceeds the allowable range, it is determined to be a low-frequency large disturbance or cumulative seeding depth deviation state, and identified as a compensation active working condition. In this case, the electric cylinder assembly 5 plays a dominant role; wherein, the seeding depth deviation threshold is... The allowable range of the seeding depth error is: The allowable range of the attitude deviation is .

[0141] When there is a sudden increase in the rate of change of seeding depth error, attitude change rate, or air spring pressure change rate within a short-term window, and the seeding depth error or attitude deviation continues to exceed the limit within a long-term window, it is determined that a state of simultaneous impact disturbance and continuous deviation exists, and it is identified as a coordinated adjustment condition. Here, "sudden increase" means that within a preset short-term window, at least one of the rates of change of seeding depth error, attitude change rate, or air spring pressure change rate is greater than the corresponding high-frequency threshold, and the rate of change reaches 1.5 to 3 times the average rate of change within that short-term window; "continuous exceedance" means that within a preset long-term window, the duration for which the seeding depth error or attitude deviation continuously exceeds the corresponding allowable range reaches 50% to 80% of the long-term window, or the number of sampling points exceeding the limit accounts for 50% to 80% of the total number of sampling points in the long-term window.

[0142] The fourth step is to calculate the air spring-electric cylinder collaborative distribution coefficient when the current operating state is the collaborative adjustment condition, and generate the air spring target pressure and electric cylinder target displacement based on the collaborative distribution coefficient.

[0143] To achieve coordinated adjustment of the air spring assembly and the electric cylinder assembly, let the air spring-electric cylinder coordinated distribution coefficient be... ,and Its expression is:

[0144] ,

[0145] in, This represents the rate of change of seeding depth error. This is for attitude deviation; This is a missed broadcast status variable; This refers to the actual pressure of the air spring. This refers to the upper limit of the allowable pressure for the air spring. This represents the remaining stroke of the electric cylinder. This is the maximum stroke of the electric cylinder; This is the allocation coefficient.

[0146] in:

[0147] ,

[0148] The distribution coefficient for the rate of change of seeding depth error. The distribution coefficient for attitude deviation. The allocation coefficient for the missed broadcast status quantity. This is the distribution coefficient for the air spring pressure state. This is the distribution coefficient for the remaining stroke state of the electric cylinder.

[0149] According to the control logic of coordinated adjustment of the air spring assembly and the electric cylinder assembly, the dynamics of seeding depth and attitude deviation are given priority, followed by the execution margin of the air spring and electric cylinder, and the missed seeding state is used as an auxiliary correction. Therefore, in this embodiment, , , , , Based on the collaborative allocation coefficient Generate the target displacement of the electric cylinder. for:

[0150] ,

[0151] in, The basic displacement compensation amount is generated based on the seeding depth error. The basic displacement compensation amount is generated by the control mechanism according to the current seeding depth error. This is the attitude deviation correction coefficient; This is a correction factor for missed broadcasts. This is the air spring support margin correction coefficient. Since the electric cylinder displacement is the main active compensation quantity, therefore, in this embodiment, , , .

[0152] Based on the collaborative allocation coefficient Generate target pressure for the air spring, target pressure for the air spring for:

[0153] ,

[0154] in, The basic support pressure is the reference pressure used by the air spring to support the seeding unit and maintain the position near the target seeding depth under the initial equilibrium condition. It can be generated through static load balance calibration, table lookup, or grading rules. The disturbance intensity index is generated based on the operating condition identification results: when identified as a high-frequency small-amplitude disturbance, the disturbance intensity index is set to a low level; when identified as a low-frequency large-amplitude disturbance or a cumulative seeding depth deviation, the disturbance intensity index is set to a medium level; when identified as a state where both impact disturbance and continuous deviation exist simultaneously, the disturbance intensity index is set to a high level. The current position of the electric cylinder; This is the maximum stroke of the electric cylinder; This is the terrain disturbance correction factor; This is a correction factor for the forming state of the electric cylinder; This is the pressure correction factor for missed broadcast conditions.

[0155] , , The settings are determined based on the impact of terrain disturbance, the remaining compensation capacity of the electric cylinder, and the degree of missed seeding on the target pressure of the air spring. This is to ensure that the terrain disturbance term plays a dominant role in the generation of the air spring target pressure, the electric cylinder stroke state term plays a supplementary compensating role, and the missed-spray state term plays an additional corrective role. In this embodiment, , , .

[0156] The fifth step involves combining the actual pressure of the air spring assembly, the air spring pressure change rate, the current position of the electric cylinder assembly, and the remaining stroke to perform coupled dynamic correction on the target pressure of the air spring and the target displacement of the electric cylinder, resulting in the first corrected target pressure of the air spring and the first corrected target position of the electric cylinder.

[0157] In the above-mentioned coupled dynamic correction process, the air spring state is used to constrain or correct the target displacement of the electric cylinder, and the electric cylinder state is used to constrain or correct the target pressure of the air spring, so as to avoid control conflicts, waste, or adjustment lag caused by the dynamic action of the air spring assembly and the electric cylinder assembly.

[0158] In this step, in order to reflect the dynamic correction relationship between the air spring assembly and the electric cylinder assembly, this application does not determine the final control quantity at once, but continuously collects the attitude deviation, the actual pressure of the air spring and the current position of the electric cylinder during the operation, and performs dynamic correction on the target pressure of the air spring and the target displacement of the electric cylinder generated in the fourth step based on the updated state quantity.

[0159] Specifically, the dynamically corrected target displacement of the electric cylinder can be expressed as:

[0160] ,

[0161] in, This represents the target displacement of the electric cylinder after the first correction. This refers to the attitude deviation correction coefficient during the dynamic correction process; This is the correction coefficient for the missed broadcast status during the dynamic correction process; This is the air spring support margin correction coefficient during the dynamic correction process. In this embodiment, , , .

[0162] When the attitude deviation increases or the current pressure of the air spring is lower than its allowable upper limit, the target displacement of the electric cylinder obtained in the fourth step is further corrected to enhance the position compensation capability of the seeding unit.

[0163] The dynamically corrected target pressure of the air spring can be expressed as:

[0164] ,

[0165] in, The target pressure for the air spring after the first correction; This refers to the terrain disturbance correction factor during the dynamic correction process; This is the correction coefficient for the electric cylinder forming state during the dynamic correction process; This is the pressure correction coefficient for the missed broadcast state during the dynamic correction process. In this embodiment, , , .

[0166] When the attitude deviation increases or the current position of the electric cylinder approaches its maximum stroke, the target pressure of the air spring obtained in the fourth step is further corrected to improve the flexible support and buffer retention capabilities.

[0167] Based on the aforementioned coupled dynamic correction relationship, the updated first correction control quantity is output in each control cycle, forming a continuous closed-loop correction relationship between the air spring assembly and the electric cylinder assembly. Each control cycle refers to a complete closed-loop control process in which the control mechanism completes one sensor signal acquisition, state calculation, working condition identification, target generation, correction calculation, and control command output according to a preset time interval.

[0168] Step 6: When the missed seeding detection unit detects that the missed seeding status or missed seeding rate exceeds the set threshold, it constructs a missed seeding linkage correction amount based on the current missed seeding status and its changes. Based on the first correction of the air spring target pressure and the first correction of the electric cylinder target displacement, it performs a second linkage correction on the air spring-electric cylinder cooperative distribution coefficient, the first correction of the air spring target pressure and the first correction of the electric cylinder target displacement, to obtain the final air spring-electric cylinder cooperative distribution coefficient, the final air spring target pressure and the final electric cylinder target displacement.

[0169] The coupling dynamic correction in step five is used to coordinate the execution state between the air spring assembly and the electric cylinder assembly; while the missed seeding linkage correction proposed in this step is used to further improve the stability of individual seeding units and maintain their weight when there is a risk of missed seeding. The higher the risk level of missed seeding, the more inclined it is to improve stability and maintain the weight, and simultaneously output warning signals, machine speed reduction commands, or seeding depth compensation correction commands to reduce the risk of missed seeding caused by fluctuations in seeding posture.

[0170] In the missed seed detection, let the theoretical number of times a seed passes through within a unit sampling window be . The actual number of tests was The missed broadcast rate It can be represented as:

[0171] ,

[0172] When the missed broadcast rate exceeds the set threshold, step six needs to be initiated.

[0173] Missed broadcast linkage correction amount It can be represented as:

[0174] ,

[0175] in, , Here, is the correction factor, This is used to characterize the degree of influence of the current missed broadcast status on the missed broadcast linkage correction amount. This is used to characterize the impact of changes in the missed seeding status on the missed seeding linkage correction. The current status is usually more important than the trend of change, therefore, it is taken as... In this embodiment, , .

[0176] This represents the change value of the missed broadcast status.

[0177] = - ,

[0178] in, This represents the missed broadcast status value from the previous moment or the previous statistical window.

[0179] Based on the aforementioned missed broadcast correction amount, the collaborative allocation coefficient is corrected to obtain the corrected collaborative allocation coefficient. for:

[0180] ,

[0181] in, The collaborative allocation correction coefficient is used to characterize the degree of influence of the missed broadcast linkage correction amount on the final collaborative allocation coefficient. The amount of additional synergistic allocation correction allowed by the missed seeding linkage correction can be determined, preferably through calibration via bench tests and field trials. To ensure the stability of the synergistic allocation results, in this embodiment, =0.05~0.2.

[0182] For the corrected collaborative allocation coefficient Perform amplitude limiting to meet the requirements. .

[0183] Among them, when When the value increases, it indicates that the weight of the electric cylinder assembly in compensating for the position of individual seeding units is increased when the risk of missed seeding rises; when When the value is increased, it indicates that the weight of the air spring assembly in maintaining the steady state of the seeding unit is enhanced.

[0184] Based on the corrected cooperative allocation coefficient The target displacement of the electric cylinder after the first correction After redistribution correction, the final target displacement of the electric cylinder is obtained. :

[0185] ,

[0186] in, This is a displacement correction coefficient, used to characterize the influence of the missed-broadcast linkage correction on the final target displacement of the electric cylinder, preferably... =0.05~0.2.

[0187] Based on the modified cooperative allocation coefficient The target displacement of the electric cylinder after the first correction After redistribution correction, the final target displacement of the electric cylinder is obtained. ::

[0188] ,

[0189] in, This is a pressure correction coefficient, used to characterize the degree of influence of the missed-broadcast linkage correction on the final target pressure of the air spring, preferably... =0.05~0.2.

[0190] Based on the final target pressure of the air spring Output pressure regulation commands to control the intake or exhaust valve to adjust the internal pressure and support stiffness of the air spring assembly; simultaneously, based on the final target displacement of the electric cylinder... Output displacement compensation commands to control the extension and retraction of the electric cylinder assembly to adjust the position of the trencher mounting frame.

[0191] After completing the adjustment work for one cycle, the control mechanism repeats the signal acquisition, state calculation, working condition identification, target generation, coupled dynamic correction, missed seeding linkage correction, and control execution steps in subsequent control cycles. When the seeding depth error or missed seeding state exceeds the preset allowable range, the control mechanism continuously outputs corresponding adjustment commands to perform closed-loop coordinated control of the air spring assembly and electric cylinder assembly until the seeding depth error and missed seeding state are restored to the preset allowable range.

[0192] The above provides a detailed description of the air spring-electric cylinder coupled seeding depth adjustment device and seeding depth control method for peanut planters provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling, characterized in that, Includes the following steps: S1. Use sensors to collect signals during the peanut planting process, and process and convert the signals into digital electrical signals; The displacement signal of the furrow opener mounting frame relative to the frame assembly is collected using a laser rangefinder sensor, the attitude signal of the seeding unit is collected using an angle sensor, the pressure signal of the air spring assembly is collected using a pneumatic pressure sensor, and the missed seeding status signal during the seeding process is collected using a photoelectric sensor. The upper end of the electric cylinder assembly is connected to the top of the frame assembly, and its lower end is connected to the air spring assembly through a connecting mechanism; the lower end of the air spring assembly is connected to the contour connecting mechanism; the front end of the contour connecting mechanism is hinged to the frame assembly, and the rear end of the contour connecting mechanism is connected to the furrowing mechanism; a seed metering device is provided between the seed box and the furrowing mechanism. S2. Calculate the current seeding depth estimate based on the data in step S1, and compare it with the target seeding depth to obtain the seeding depth error and its changing trend. S3. Identify the current operating status; Within the preset short-time window, when the absolute value of the seeding depth error is less than And the absolute values ​​of the attitude deviations are all less than When the seeding depth error rate is greater than a certain value, it is considered a small disturbance state; when the seeding depth error rate is greater than a certain value, it is considered a small disturbance state. The rate of change of attitude is greater than Or the rate of change of air spring pressure is greater than When a high-frequency disturbance is detected, the air spring assembly plays a dominant role. Within a preset long-term window, when the absolute value of the seeding depth error continuously exceeds [a certain value]... The average seeding depth error consistently exceeds Or the average attitude deviation consistently exceeds It is determined to be a low-frequency large disturbance or a cumulative seeding depth deviation state, and is identified as an active compensation condition, in which case the electric cylinder assembly plays a leading role. When the rate of change of seeding depth error is greater than within the short-time window The rate of change of attitude is greater than Or the rate of change of air spring pressure is greater than At the same time, the rate of change reaches 1.5 to 3 times the average rate of change within the short time window; and within the preset long time window, the duration for which the seeding depth error or attitude deviation continuously exceeds the corresponding allowable range reaches 50% to 80% of the long time window, or the number of sampling points exceeding the limit accounts for 50% to 80% of the total number of sampling points in the long time window, which is identified as a coordinated adjustment condition. S4. When the current working state is the coordinated adjustment condition, calculate the air spring-electric cylinder coordinated distribution coefficient, and generate the air spring target pressure and electric cylinder target displacement based on the coordinated distribution coefficient. In step S4, let the air spring-electric cylinder cooperative distribution coefficient be... ,and : ， in, This represents the rate of change of seeding depth error. This is for attitude deviation; This is a missed broadcast status variable; This refers to the actual pressure of the air spring. This refers to the upper limit of the allowable pressure for the air spring. This represents the remaining stroke of the electric cylinder. This is the maximum stroke of the electric cylinder; The distribution coefficient for the rate of change of seeding depth error. The distribution coefficient for attitude deviation. The allocation coefficient for the missed broadcast status quantity. This is the distribution coefficient for the air spring pressure state. This is the distribution coefficient for the remaining stroke state of the electric cylinder, and ; Based on the collaborative allocation coefficient Generate target displacement of electric cylinder : ， in, This is the basic displacement compensation amount generated based on the seeding depth error; This is the attitude deviation correction coefficient; This is a correction factor for missed broadcasts. This is a correction factor for the air spring support margin. Based on the collaborative allocation coefficient Generate air spring target pressure : ， in, To provide basic support against pressure; This is an indicator of disturbance intensity. The current position of the electric cylinder; This is the maximum stroke of the electric cylinder; This is the terrain disturbance correction factor; This is a correction factor for the forming state of the electric cylinder; This is the pressure correction factor for missed broadcast conditions. ; S5. Perform coupled dynamic correction on the air spring target pressure and electric cylinder target displacement to obtain the air spring target pressure and electric cylinder target position after the first correction. S6. When the missed seeding status quantity or missed seeding rate exceeds the set threshold, a missed seeding linkage correction quantity is constructed based on the current missed seeding status quantity and the change value of the missed seeding status quantity. Based on step S5, a second linkage correction is performed on the air spring-electric cylinder cooperative distribution coefficient, the air spring target pressure after the first correction, and the electric cylinder target displacement after the first correction.

2. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 1, characterized in that, The contour-following connection mechanism includes: Two front hinge shafts are arranged horizontally and are parallel to each other. Both front hinge shafts are hinged to the frame assembly. Two rear hinge shafts are respectively arranged in a corresponding manner to two front hinge shafts. The rear hinge shafts and the front hinge shafts are parallel to each other. The ends of the rear hinge shafts are connected to the ends of the corresponding front hinge shafts by connecting rods. The rear hinge shafts are hinged to the air spring assembly. The rear profile support and the end of the rear hinge shaft are respectively hinged to the rear profile support, and the rear profile support is connected to the trenching mechanism. Trenching equipment includes: Two symmetrically arranged trenchers; The furrow opener support rod has its upper end fixedly connected to the furrow opener mounting frame and its lower end connected to the furrow opener. The trencher mounting bracket has trencher mounting brackets fixed on both sides of the rear contour bracket.

3. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 2, characterized in that, In step S1, Analog voltage signal output by laser rangefinder The converted value is a digital quantity. Its expression is: ， in, This is the reference voltage for analog-to-digital conversion. For the number of bits in the analog-to-digital conversion, The range of the laser rangefinder sensor. Pitch angle analog voltage signal output by angle sensor and roll angle analog voltage signal After conversion, the pitch angle digital value is obtained. and roll angle digital quantity : ， in, The analog-to-digital conversion reference voltage for the pitch angle; The number of bits for the analog-to-digital conversion; The attitude range for pitch angle; The analog-to-digital conversion reference voltage for roll angle; The attitude range for the roll angle; Displacement value After calibration and conversion, it is: ， ， ， in, This represents the pitch angle displacement value; This is the roll angle displacement value; For displacement calibration coefficients; This refers to the pitch angle displacement calibration coefficient; This is the roll angle displacement calibration coefficient; This is the zero-point compensation amount for the pitch angle; This is the zero-point compensation amount for the roll angle.

4. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 1, characterized in that, In step S2, the target depth is used for seeding. Based on the displacement value Calculate the current seeding depth estimate : ， in, For seeding depth error; , in, The baseline seeding depth is set.

5. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 1, characterized in that, In step S5, When the attitude deviation increases or the current pressure of the air spring is lower than its allowable upper limit, an additional dynamic correction is applied to the target displacement of the electric cylinder in step S4. The dynamically corrected target displacement of the electric cylinder is: ， in, This represents the target displacement of the electric cylinder after the first correction. This refers to the attitude deviation correction coefficient during the dynamic correction process; This is the correction coefficient for the missed broadcast status during the dynamic correction process; This is the correction coefficient for the air spring support margin during the dynamic correction process. When the attitude deviation increases or the current position of the electric cylinder approaches its maximum stroke, the target pressure of the air spring in step S4 is dynamically corrected. The dynamically corrected target pressure of the air spring is: ， in, The target pressure for the air spring after the first correction; This refers to the terrain disturbance correction factor during the dynamic correction process; This is the correction coefficient for the electric cylinder forming state during the dynamic correction process; This is the pressure correction coefficient for the missed broadcast status during the dynamic correction process.

6. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 1, characterized in that, In step S6, Let the theoretical number of times the seed passes through within a unit sampling window be . The actual number of tests was The missed broadcast rate It can be represented as: ， When the missed broadcast rate exceeds the set threshold, step S6 is initiated. Missed broadcast linkage correction amount for: ， in, This is used to characterize the degree of influence of the current missed broadcast status on the missed broadcast linkage correction amount. Used to characterize the degree of influence of changes in the missed seeding status quantity on the missed seeding linkage correction quantity. ; This represents the change value of the missed broadcast status. = - ， in, This represents the missed broadcast status from the previous moment or the previous statistical window. Based on the missed broadcast correction amount, the collaborative allocation coefficient is corrected to obtain the corrected collaborative allocation coefficient. for: ， in, The collaborative allocation correction coefficient is used to characterize the degree of influence of the missed broadcast linkage correction amount on the final collaborative allocation coefficient. For the corrected collaborative allocation coefficient Perform amplitude limiting to meet the following requirements: ， Based on the corrected cooperative allocation coefficient The target displacement of the electric cylinder after the first correction After redistribution correction, the final target displacement of the electric cylinder is obtained. : ， in, This is a displacement correction coefficient, used to characterize the degree of influence of the missed-broadcast linkage correction on the final target displacement of the electric cylinder. Based on the modified cooperative allocation coefficient The target displacement of the electric cylinder after the first correction After redistribution correction, the final target displacement of the electric cylinder is obtained. : ， in, This is the pressure correction coefficient, used to characterize the degree of influence of the missed broadcast linkage correction on the final target pressure of the air spring; Based on the final target spring pressure It controls the intake or exhaust valve to adjust the internal pressure and support stiffness of the air spring assembly; simultaneously, it adjusts the final target displacement of the electric cylinder. Output displacement compensation commands to control the extension and retraction of the electric cylinder assembly to adjust the position of the trencher mounting frame.

7. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 1, characterized in that, The air spring assembly includes: The elastic airbag is equipped with a pressure sensor and an air source interface. An air intake valve and an air exhaust valve are connected between the air source interface and the elastic airbag. Upper mounting base: The upper end of the elastic airbag is provided with an upper mounting base; The lower mounting base is provided at the lower end of the elastic airbag.

8. The method for controlling planting depth based on peanut planting unit air spring-electric cylinder coupling according to claim 1, characterized in that, The electric cylinder assembly includes a telescopic rod, which is disposed inside the cylinder body; The upper end of the telescopic rod is connected to the output shaft of the reduction mechanism, and the output end of the drive motor is connected to the reduction mechanism; The lower end of the telescopic rod is connected to the air spring assembly via a connecting mechanism.

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