Method for improving the effect of unpredictable seed spacing

Abstract

A method for mitigating the unpredictable effects of seed metering, belonging to the field of seed metering control for electric-driven seeders, is disclosed. The method comprises the following steps: Step 1: Calculation of the reference rotational speed of the ground wheel; Step 2: Calculation of the tractor speed; the tractor speed is calculated based on the reference rotational speed of the ground wheel, the target plant spacing, the reduction ratio of the seeding motor, the number of holes in the seed metering tray, and the reference rotational speed of the seed metering motor; Step 3: Sampling of the seeding time window; Step 4: Calculation of the current rotational speed of the seeding motor; the current rotational speed of the seeding motor is calculated based on the total seeding time and the angle occupied by each seed on the seed metering tray; Step 5: Calculation of the design dead zone and the number of error seeds; the difference between the reference rotational speed of the seed metering motor and the current rotational speed of the seed metering motor is converted into a seed tray rotational speed difference, and then converted into an angular velocity; the angular velocity is integrated to obtain the real-time error angle, and the real-time error angle is converted into the number of error seeds; Step 6: Error mitigation compensation. This invention can improve the seeding effect and correct long-term systematic deviations in plant spacing.

Description

Technical Field

[0001] This invention belongs to the field of seeding control for electric-driven seeders, and specifically relates to a method for improving the even spacing of plants to mitigate the unpredictable effects of seeding. Background Technology

[0002] Currently, most electric-drive seeders use the ground wheel as a signal source to obtain the tractor's real-time speed. A encoder is installed at the ground wheel to calculate the number of pulses provided by the encoder during movement, thus determining the speed. This single-encoder ground wheel design offers advantages such as low cost, ease of installation, and good maintenance, and is widely used in farms and other local areas in Heilongjiang and Inner Mongolia. It has been proven that, with proper encoder installation, it can adapt to complex sowing conditions such as wetlands, clay soils, sandy areas, and mountainous terrain, accurately reflecting real-time speed. A good seed spacing depends not only on accurate speed measurement but also on a fast and precise motor speed response. Considering the concentrated and quantitative impact of all non-ideal factors in the seed metering system (such as ground wheel slippage, transmission losses, inconsistent seed placement points, and differences in seed shape and size) on the final seed spacing, monitoring and feedback of the actual seed placement status is crucial for achieving high-precision intelligent sowing.

[0003] Due to varying degrees of non-ideal factors affecting the sowing of each individual plant (such as wheel slippage, transmission loss, inconsistent seed placement points, and differences in seed shape and size), there is a significant difference between the actual number of seeds sown and the ideal number of seeds sown. Furthermore, after a long period of sowing, the consistency of sowing among individual plants is poor. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art and provide a method for improving the even distribution of plant spacing to mitigate the unpredictable effects of seeding. This method improves sowing results and corrects long-term systematic deviations in plant spacing.

[0005] The innovation of this invention lies in: the seed metering disc speed is deduced from the seeding interval (the seed metering motor and the seed metering disc speed differ by a reduction ratio, and their actual speeds are different), thereby obtaining the actual seed metering motor speed. The theoretical motor speed is obtained from the ground wheel. The difference between the two reflects the error caused by non-ideal factors in the seeding process. This error is integrated and accumulated, and the accumulated error is compensated to the given motor speed through a feedforward method, thereby achieving an adaptive compensation mechanism for unpredictable non-ideal errors in the transmission process pre-built at the input end.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for mitigating the unpredictable effects of seeding by averaging plant spacing includes the following steps:

[0008] Step 1: Calculation of reference rotational speed of the ground wheel

[0009] Acquiring continuous incremental encoder A pulse signal, The value range is 5-10, and the position output signals of two absolute encoders before and after the same time period are read simultaneously; during the interruption of signal acquisition, the incremental encoder is calculated at... The rotational speed within the corresponding time window of each pulse signal is used as the reference rotational speed of the ground wheel; the same time period is the [number missing]. The time when the pulse signal occurs;

[0010] Step 2: Tractor speed calculation

[0011] The tractor speed is calculated based on the ground wheel reference speed obtained in step 1, as well as the target plant spacing, seed motor reduction ratio, number of holes in the seed metering tray, and seed motor reference speed.

[0012] Step 3: Sampling within the seeding time window

[0013] According to the number of acupoints in the seed arranging plate ,sampling The time interval between seeds, and satisfying: / It is an integer. / ≥4, and >3; If the number of holes in the seed tray It is a prime number or cannot satisfy the condition. / It is an integer, and / ≥4, then use ( + ) / Sampling is performed in integer form, i.e., one round of sampling ( + ) / Next; Requirement >3; This represents a fixed constant, taking the value of 1 or 3; then calculate each... Time within a seed cycle;

[0014] Step 4: Calculation of the current speed of the seeding motor

[0015] Based on the total time of seeding and The angle occupied by each seed on the seed metering tray Calculate the current rotational speed of the sowing motor;

[0016] Step 5: Design dead zone and error seed number calculation

[0017] The design includes a dead zone, which is activated only when the cumulative error is greater than 0.5 seeds. To achieve this, the difference between the reference speed of the seed metering motor and the current speed of the seed metering motor is converted into the seed disc speed difference and then into angular velocity. The angular velocity is integrated to obtain the real-time error angle, and then the real-time error angle is converted into the number of error seeds.

[0018] Step 6: Error Amortization Compensation

[0019] When the accumulated error exceeds the set dead zone, within a preset distance, the number of error seeds is evenly distributed across the theoretical plant spacing to calculate the real-time plant spacing change and extract the number of error seeds. This achieves error amortization compensation.

[0020] Furthermore, in step 1, the position output signal is denoted as:

[0021] (1)

[0022] in, Indicates the number of pulses in an incremental encoder; It represents any given moment in time;

[0023] During the process of interrupting the acquisition signal, the reference rotation speed of the ground wheel is calculated, and the calculation formula is shown in the following formula (2):

[0024] (2);

[0025] in, for Time's up + The time period for capturing a specific moment; This refers to the number of pulses per revolution of an incremental encoder. This is the reference speed for the ground wheel.

[0026] Furthermore, in step 2, the calculation formula for the reference speed of the seed metering motor is shown in the following formula (4):

[0027] (4)

[0028] in, Reference speed for the seed metering motor, in rpm; The speed of the tractor; Target plant spacing; This refers to the reduction ratio of the sowing motor; This refers to the number of holes in the seed tray;

[0029] The tractor speed Reference speed of ground wheel The conversion yields:

[0030] =

[0031] in, It is the effective rolling outer diameter of the ground wheel.

[0032] Furthermore, in step 3, each The calculation formula for the time within a seed cycle is shown in equation (5) below:

[0033] (5)

[0034] in, Indicates the time at that moment; Indicates the time taken between two consecutive moments; set The time interval between seeds is represented as: ,default .

[0035] Furthermore, in step 4, the total time for seed placement is calculated using the following formula (6):

[0036] (6)

[0037] in, The total time for seeding, express Summing over time;

[0038] The The angle occupied by each seed on the seed metering plate is calculated using the following formula (7):

[0039] (7)

[0040] in, for The angle occupied by each seed on the seed metering plate, in rad;

[0041] The rotational speed of the current seeding motor is calculated by the following formula (8);

[0042] (8)

[0043] in, This represents the current rotational speed of the sowing motor.

[0044] Furthermore, in step 5, the difference between the reference speed of the seed metering motor and the current speed of the seeding motor is converted into the seed disc speed difference and then into angular velocity. The calculation formula is shown in the following formula (9):

[0045] (9)

[0046] in, The angular velocity of the seed metering disc; This is the reference speed for the seed metering motor; This refers to the current rotational speed of the sowing motor.

[0047] The real-time error angle is obtained by integrating the angular velocity, and its calculation formula is shown in the following formula (10):

[0048] (10)

[0049] in, This is the real-time error angle;

[0050] Then, the real-time error angle is converted into an error seed number, and its calculation formula is shown in the following formula (11):

[0051] (11)

[0052] in, This represents the number of error seeds.

[0053] Furthermore, in step 6, the real-time plant spacing change is calculated, and the calculation formula is shown in the following formula (12):

[0054] (12)

[0055] in, This represents the real-time change in plant spacing;

[0056] Equation (12) is further rearranged, and the number of error types is extracted. This achieves error amortization compensation, and its calculation formula is shown in equation (13) below:

[0057] (13).

[0058] The advantages of this invention compared to existing technologies are as follows: Regarding the motor itself, acceleration, current, and torque are interrelated. This invention cleverly utilizes this relationship to extract the target motor acceleration value from the current inner loop control. Existing seeding motor control only acquires the real-time vehicle speed value, ignoring the dynamic response process of the seeding motor when the vehicle speed changes, thus failing to guarantee uniformity of plant spacing during the seeding process. This invention aims to enable the rotational dynamics of the seeding motor to follow the changing trend of the tractor speed, thereby improving the uneven plant spacing phenomenon that occurs during the acceleration and deceleration phases of the tractor. Attached Figure Description

[0059] Figure 1This is a schematic diagram illustrating uneven seed distribution within the seed delivery tube.

[0060] Figure 2 This is a control block diagram with feedback and precise compensation.

[0061] Figure 3 This is a schematic diagram of the control part of the method for improving the unpredictable impact of seeding in this invention. Detailed Implementation

[0062] This embodiment provides a method for improving the even spacing of plants to mitigate the unpredictable effects of seeding, including the following steps:

[0063] Step 1: Calculation of reference rotational speed of the ground wheel

[0064] Acquiring continuous incremental encoder A pulse signal, The value range is 5-10, and the position output signals of two absolute encoders before and after the same time period are read simultaneously; during the interruption of signal acquisition, the incremental encoder is calculated at... The rotational speed within the time window corresponding to each pulse signal (calculated) Time's up + The capture time period at each moment The incremental encoder speed is calculated and used as a reference speed for the ground wheel; the same time period is the first... The time when the pulse signal occurs;

[0065] The position output signal is denoted as:

[0066] (1)

[0067] in, Indicates the number of pulses in an incremental encoder; It represents any given moment in time;

[0068] During the process of interrupting the acquisition signal, the reference rotation speed of the ground wheel is calculated, and the calculation formula is shown in the following formula (2):

[0069] (2);

[0070] in, for Time's up + The time period for capturing a specific moment; This refers to the number of pulses per revolution of an incremental encoder. This is the reference speed for the ground wheel.

[0071] Step 2: Tractor speed calculation

[0072] The tractor speed is calculated based on the ground wheel reference speed obtained in step 1, as well as the target plant spacing, seed motor reduction ratio, number of holes in the seed metering tray, and seed motor reference speed.

[0073] For a multi-row seeder, due to the differences between individual motors, the speed regulation performance of each control unit is different under the same control command. Over long periods of operation, the total number of rotations of each row's seeder motor will differ, resulting in different seed counts for each row. The formula for calculating the reference speed of the seed metering motor is shown in equation (4) below:

[0074] (4)

[0075] in, Reference speed for the seed metering motor, in rpm; The speed of the tractor; Target plant spacing; This refers to the reduction ratio of the sowing motor; This refers to the number of holes in the seed tray;

[0076] The tractor speed Reference speed of ground wheel The conversion yields:

[0077] =

[0078] in, It is the effective rolling outer diameter of the ground wheel.

[0079] Because seeders operate in multiple rows on ridges, the motor adjustment performance of each row is different, and the degree of influence of individual non-ideal factors in each row is different. Over a long period of cultivation, the total number of seeds sown between rows has become increasingly different, and there is a systematic deviation in plant spacing.

[0080] A diagram illustrating the seed drop process in the seed delivery tube is shown below. Figure 1 As shown, when the seed metering disc rotates, the seeds fall one after another from the seed guide tube. When they reach the seed counting sensor, they are scanned and a narrow pulse is output. The host computer terminal will then count once.

[0081] Step 3: Sampling within the seeding time window

[0082] During seeder operation, unpredictable and complex interferences in the speed control performance and seed metering device (such as wheel slippage, transmission loss, inconsistent seed placement points, and differences in seed shape and size) cause irregular seed placement by the seed metering device, resulting in systematic deviations. The distance between each pair of seeds varies, causing inconsistent pulse signal timing from the seed counting sensor. For example... Figure 1The distance between the green and blue seeds is different from the distance between the blue and red seeds.

[0083] To accurately and quickly grasp the seeding status within one circle of the seeding tray, it is not sufficient to simply calculate the time interval between two seeds. Therefore, a time sampling method that takes into account different numbers of holes in the seeding tray is designed:

[0084] According to the number of acupoints in the seed arranging plate ,sampling The time interval between seeds, and satisfying: / It is an integer. / ≥4 (meaning that within each ring of the seeding tray, at least 4 non-repeating sampling comparisons of the number of seed holes are performed), and >3 (meaning that sampling only 3 seeds at intervals is insufficient to accurately reflect the dynamic time interval; generally, the number of holes in the seeding tray should be less than 100 and greater than 20); if the number of holes in the seeding tray... It is a prime number or cannot satisfy the condition. / It is an integer, and / ≥4, then based on the existing number of acupoints, adopt ( + ) / Sampling is performed in integer form, i.e., one round of sampling ( + ) / Next; Requirement >3; Represents a fixed constant, taking the value of 1 or 3; guarantees a prime number. If it is divisible by 4, then calculate each... The time within each seed cycle; its calculation formula is shown in equation (5) below:

[0085] (5)

[0086] in, Indicates the time at that moment; Indicates the time taken between two consecutive moments; set The time interval between seeds is represented as: Considering the influence of other uncontrollable factors on the seed during the seed tube's descent, equation (5) defaults to... This is also why we cannot analyze the time interval of any one or two seeds in isolation.

[0087] Step 4: Calculation of the current speed of the seeding motor

[0088] Based on the total time of seeding and The angle occupied by each seed on the seed metering tray Calculate the current rotational speed of the sowing motor;

[0089] The total time for seeding is calculated using the following formula (6):

[0090] (6)

[0091] in, The total time for seeding, express Summing over time;

[0092] The The angle occupied by each seed on the seed metering plate is calculated using the following formula (7):

[0093] (7)

[0094] in, for The angle occupied by each seed on the seed metering plate, in rad;

[0095] The rotational speed of the current seeding motor is calculated by the following formula (8);

[0096] (8)

[0097] in, This represents the current rotational speed of the sowing motor;

[0098] Formula (4) reflects the sowing motor speed obtained from the ground wheel encoder, i.e., the reference speed; Formula (8) reflects the sowing motor speed obtained from the actual seed counting sensor. Theoretically, the two are equal, but in practice, there is a real-time dynamic deviation. Unlike the traditional feedback control based on the actual speed obtained from the motor shaft encoder, this method uses the actual seeding conditions to determine the motor speed control. The specific operation block diagram is as follows: Figure 2 As shown.

[0099] Step 5: Design dead zone and error seed number calculation

[0100] During the calculation of the seeding interval, the seeds inevitably bump into each other during the fall, resulting in relatively short / long intervals. This is considered noise rather than a trend and is not addressed. Therefore, a dead zone is designed, and compensation is only activated when the cumulative error exceeds 0.5 seeds to avoid sensitivity to random noise. To this end, the difference between the reference speed of the seeding motor and the current speed (actual speed) is converted into the seed disc speed difference and then into angular velocity; the calculation formula is shown in equation (9) below:

[0101] (9)

[0102] in, The angular velocity of the seed metering disc; This is the reference speed for the seed metering motor; This refers to the current rotational speed of the sowing motor.

[0103] The real-time error angle is obtained by integrating the angular velocity, and its calculation formula is shown in the following formula (10):

[0104] (10)

[0105] in, This is the real-time error angle;

[0106] Then, the real-time error angle is converted into an error seed number, and its calculation formula is shown in the following formula (11):

[0107] (11)

[0108] in, This represents the number of error seeds;

[0109] The angular velocity is integrated to obtain the real-time error angle, and then the real-time error angle is converted into an error seed number.

[0110] Step 6: Error Amortization Compensation

[0111] When the accumulated error exceeds the set dead zone, within a preset distance, the number of error seeds is evenly distributed across the theoretical plant spacing to calculate the real-time plant spacing change and extract the number of error seeds. This achieves error amortization compensation. Given the varying unpredictable combined interference affecting each sowing unit in a row, independent calculations and compensation are performed within each row. Compensation calculations begin when the accumulated error exceeds 0.5 seeds. The plan is to complete the error seed value within a 1-meter distance, although it's possible the 1-meter distance could be changed to 2 meters or other lengths in the plan. Within 1 meter, based on the set plant spacing, the theoretical number of seeds is 1 / +1, at this point, the aim is to spread the error to the theoretical plant spacing and calculate the real-time plant spacing change, the calculation formula of which is shown in the following formula (12):

[0112] (12)

[0113] in, This represents the real-time change in plant spacing;

[0114] Equation (12) is further rearranged, and the number of error types is extracted. This achieves error amortization compensation, and its calculation formula is shown in equation (13) below:

[0115] (13).

[0116] Figure 3 exist Figure 2 Based on this, equation (12) is applied to the feedback loop in the form of actual operation. Figure 3 The part within the red dashed box.

Claims

1. A method for improving the unpredictability of seeding spacing, characterized in that: Includes the following steps: Step 1: Calculation of reference rotational speed of the ground wheel Acquiring continuous incremental encoder A pulse signal, The value range is 5-10, and the position output signals of two absolute encoders before and after the same time period are read simultaneously; during the interruption of signal acquisition, the incremental encoder is calculated at... The rotational speed within the corresponding time window of each pulse signal is used as the reference rotational speed of the ground wheel; the same time period is the [number missing] pulse signal. The time when the pulse signal occurs; Step 2: Tractor speed calculation The tractor speed is calculated based on the ground wheel reference speed obtained in step 1, as well as the target plant spacing, seed motor reduction ratio, number of holes in the seed metering tray, and seed motor reference speed. Step 3: Sampling within the seeding time window According to the number of acupoints in the seed arranging plate ,sampling The time interval between seeds, and satisfying: / It is an integer. / ≥4, and >3; If the number of holes in the seed tray It is a prime number or cannot satisfy the condition. / It is an integer, and / ≥4, then use ( + ) / Sampling is performed in integer form, i.e., one round of sampling ( + ) / Next; Requirement >3; This represents a fixed constant, taking the value of 1 or 3; then calculate each... Time within a seed cycle; Step 4: Calculation of the current speed of the seeding motor Based on the total time of seeding and The angle occupied by each seed on the seed metering tray Calculate the current rotational speed of the sowing motor; Step 5: Design dead zone and error seed number calculation The design includes a dead zone, which is activated only when the cumulative error is greater than 0.5 seeds. To achieve this, the difference between the reference speed of the seed metering motor and the current speed of the seed metering motor is converted into the seed disc speed difference and then into angular velocity. The angular velocity is integrated to obtain the real-time error angle, and then the real-time error angle is converted into the number of error seeds. Step 6: Error Amortization Compensation When the accumulated error exceeds the set dead zone, within a preset distance, the number of error seeds is evenly distributed across the theoretical plant spacing to calculate the real-time plant spacing change and extract the number of error seeds. This achieves error amortization compensation.

2. The method for evenly distributing plant spacing according to claim 1, characterized in that: In step 1, the position output signal is denoted as: (1) in, Indicates the number of pulses in an incremental encoder; It represents any given moment; During the process of interrupting the acquisition signal, the reference rotation speed of the ground wheel is calculated, and the calculation formula is shown in the following formula (2): (2)； in, for Time's up + The time period for capturing a specific moment; This refers to the number of pulses per revolution of an incremental encoder. This is the reference speed for the ground wheel.

3. The method for evenly distributing plant spacing according to claim 2, characterized in that: In step 2, the calculation formula for the reference speed of the seed metering motor is shown in the following formula (4): (4) in, Reference speed for the seed metering motor, in rpm; The speed of the tractor; Target plant spacing; This refers to the reduction ratio of the sowing motor; This refers to the number of holes in the seed tray; The tractor speed Reference speed of ground wheel The conversion yields: = in, It is the effective rolling outer diameter of the ground wheel.

4. The method for evenly distributing plant spacing according to claim 3, characterized in that: In step 3, each The calculation formula for the time within a seed cycle is shown in equation (5) below: (5) in, Indicates the time at that moment; Indicates the time taken between two consecutive moments; set The time interval between seeds is represented as: ,default .

5. The method for evenly distributing plant spacing according to claim 4, characterized in that: In step 4, the total time for seed placement is calculated using the following formula (6): (6) in, The total time for seeding, express Summing over time; The The angle occupied by each seed on the seed metering plate is calculated using the following formula (7): (7) in, for The angle occupied by each seed on the seed metering plate, in rad; The rotational speed of the current seeding motor is calculated by the following formula (8); (8) in, This represents the current rotational speed of the sowing motor.

6. The method for evenly distributing plant spacing according to claim 5, characterized in that: In step 5, the difference between the reference speed of the seed metering motor and the current speed of the seeding motor is converted into the seed tray speed difference and then into angular velocity. The calculation formula is shown in the following formula (9): (9) in, The angular velocity of the seed metering disc; This is the reference speed for the seed metering motor; This refers to the current rotational speed of the sowing motor; The real-time error angle is obtained by integrating the angular velocity, and its calculation formula is shown in the following formula (10): (10) in, This is the real-time error angle; Then, the real-time error angle is converted into an error seed number, and its calculation formula is shown in the following formula (11): (11) in, This represents the number of error seeds.

7. The method for evenly distributing plant spacing according to claim 6, characterized in that: In step 6, the real-time plant spacing change is calculated, and the calculation formula is shown in the following formula (12): (12) in, This represents the real-time change in plant spacing; Equation (12) is further rearranged, and the number of error types is extracted. This achieves error amortization compensation, and its calculation formula is shown in equation (13) below: (13)。

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