Low-loss rape header, control method and harvester

Abstract

The invention provides a low-loss rape header, a control method and a harvester. The low-loss rape header comprises an air blowing loss reducing device and a control unit. The air-blowing loss reduction device comprises a duckbilled nozzle, a nozzle joint, a steering engine, an airflow hose, a brushless fan, a fan bracket, an air speed control box, a torque sensor and a shattering detection sensor; the duckbilled nozzle is connected with the vertical surface of the back of the divider head of the middle divider through a nozzle joint and points to the inlet direction of the feeding auger; the steering engine is connected with the duckbilled nozzle and is used for driving the duckbilled nozzle to rotate up and down; the brushless fan is mounted at the seedling dividing head and is connected to the duckbilled nozzle through an airflow hose; the wind speed control box is connected with the brushless fan; the control unit adjusts the wind speed of the duckbilled nozzle by controlling the rotating speed of the brushless fan through a sliding mode control algorithm based on fuzzy PID according to signals collected by the shattering detection sensor and the torque sensor, the duckbilled nozzle is controlled to rotate up and down through the steering engine to adjust the spraying angle, and grain loss is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of harvesters, and in particular relates to a low-loss rapeseed harvesting platform, a control method and a harvester. Background Art

[0002] Chinese invention patent CN115443813A has made improvements on the existing corn harvesting platform and developed a harvesting platform suitable for harvesting small-grain crops such as rapeseed, quinoa, and sorghum. This type of harvesting platform is longitudinally longer than the traditional rice and wheat harvesting platform, and is equipped with a straw separating and feeding device to facilitate the entry of the stems into the harvesting platform auger, and has good adaptability to fallen crops. However, due to the lengthening of the harvesting platform, the disturbance stroke of the crop before entering the auger becomes longer, the disturbance time is longer, and the harvesting platform loss will also increase. If the feeding and feeding speed does not match the forward speed, the loss will be greater. If the feeding and feeding is too fast, the stem pulling feeding mechanism will increase the impact on the crop and cause splashing losses.

[0003] Chinese invention patent CN116868777A designs an active feeding harvester with fallen grain recovery to address the increased grain loss caused by longitudinal lengthening of the harvester. Fallen grains from the harvester are collected and transported to the feed auger. Modular hydraulic components are used to drive the harvester components, while matching the speed of the straw-pulling mechanism with the forward speed to ensure optimal harvester operation. The hydraulic drive system can be used for both grain harvesters and ordinary rice and wheat harvesters, increasing machine utilization. However, the speed matching process is a complex, nonlinear, time-varying process with a lag. The controller also takes time to issue control commands to drive the motor speed, resulting in the travel speed and straw-pulling mechanism speed failing to reach the optimal speed ratio in a timely manner, potentially leading to feed blockage and greater grain loss. Furthermore, the force required to drive the row divider and straw-pulling mechanism is relatively large, resulting in increased energy consumption.

[0004] Chinese invention patent CN101362337A describes a device for recovering seed splashed by the vertical cutters of a rapeseed harvesting header. During harvesting, the vertical cutters sever rapeseed branches, and the splashed seeds enter a collection structure driven by gravity, forward movement, and negative pressure airflow. The base of the crop divider is tilted to prevent seeds from ejecting, and the fan generates suction to collect the splashed seeds. However, this device only recovers the splashed seeds generated by the vertical cutters of the rapeseed harvesting header and is not suitable for recovering the splashed seeds of a pull-stem harvesting header.

[0005] Prior art has proposed a method and device for online collection of seed droplets from a rapeseed harvester using horizontal positive pressure airflow for row-based rapeseed sowing. The collection process has been analyzed and optimized through virtual simulation, bench testing, and theoretical calculations. However, this device targets seed droplets generated during rapeseed harvester reel operation and is unsuitable for recovering seed splashes from the grain divider on a grain harvester. Summary of the Invention

[0006] In response to the above technical problems, the present invention provides a low-loss rapeseed harvesting platform and a control method and a harvester to reduce grain loss.

[0007] Note that the inclusion of these objectives does not preclude the existence of other objectives. One embodiment of the present invention does not necessarily achieve all of the above objectives. Objectives other than the above objectives may be extracted from the description of the specification, drawings, and claims.

[0008] The present invention achieves the above technical objectives through the following technical means.

[0009] A low-loss rapeseed harvesting platform, comprising an air-blowing loss reduction device and a control unit;

[0010] The air blowing loss reduction device includes a duckbill nozzle, a nozzle joint, an air flow hose, a brushless fan, a fan bracket, a wind speed control box, a servo, a torque sensor and a grain falling detection sensor; the duckbill nozzle is connected to the vertical surface of the back of the grain dividing head of the intermediate grain divider through the nozzle joint, pointing to the direction of the feeding auger inlet; the servo is connected to the duckbill nozzle, and the servo is used to drive the duckbill nozzle to rotate up and down; the brushless fan is installed on the grain dividing head through the fan bracket and is connected to the duckbill nozzle through the air flow hose; the wind speed control box is connected to the brushless fan; the grain falling detection sensor is installed in the middle of the grain divider of the intermediate grain divider, and is used to detect the grain falling loss signal during the feeding process of the cutting table and transmit it to the control unit; the torque sensor is installed on the cutting table drive shaft, and is used to detect the torque signal of the cutting table drive shaft and transmit it to the control unit;

[0011] The control unit is respectively connected to the torque sensor, the particle detection sensor, the wind speed control box and the servo. According to the signals collected by the particle detection sensor and the torque sensor, the wind speed of the duckbill nozzle is adjusted by controlling the speed of the brushless fan, and the spray angle is adjusted by controlling the duckbill nozzle to rotate up and down through the servo.

[0012] In the above scheme, the grass-dividing head is a triangular cone structure, with its tip facing the working direction to separate the grass. A through hole is provided on the vertical surface of the back for installing a duckbill nozzle, and the inner wall of the through hole is provided with an anti-wear coating.

[0013] In the above scheme, a threaded through hole is provided on the side of the nozzle joint, one side is connected to the air flow hose through a quick joint, and the other side is fixed with a duckbill nozzle through a detachable interface. The servo is installed on the head of the divider through a servo bracket, and the servo is connected to the duckbill nozzle through a servo connecting rod to control the up and down rotation of the duckbill nozzle to adjust the spray angle; the up and down spray angle adjustment range of the duckbill nozzle is 0°~45°.

[0014] In the above solution, the air flow hose is a corrugated silicone tube, one end of the air flow hose is sealed connected to the air outlet of the brushless blower, and the other end is sealed connected to the air inlet of the duckbill nozzle.

[0015] In the above solution, the brushless fan is connected to the wind speed control box through a driver. The driver receives the PWM signal from the wind speed control box and adjusts the speed of the brushless fan in real time. A wind speed sensor is provided in the duckbill nozzle, which is used to detect the wind speed in the duckbill nozzle and transmit it to the control unit.

[0016] The blades of the brushless fan are backward-inclined centrifugal impellers, and the driver has a built-in overload protection module, which automatically reduces the speed and alarms when the motor current exceeds the threshold.

[0017] In the above solution, an anti-grass entanglement guard is provided at the bottom of the cutting platform frame, and the anti-grass entanglement guard covers the cross-cutting knife and maintains a gap with the plowing chain, and the surface of the anti-grass entanglement guard is coated with hydrophobic material.

[0018] In the above scheme, the outlet end of the duckbill nozzle is a duckbill-shaped flat structure, the ejected airflow is fan-shaped, the fan-shaped coverage angle is 30°~60°, and the fan-shaped coverage forms a wind curtain. The cutting table is covered by multiple duckbill nozzles, and the coverage width is 1.2~1.5 times the width of the feeding auger inlet, so that the air blowing loss reduction device is a wind curtain type air blowing loss reduction device.

[0019] A harvester comprises the low-loss rapeseed harvesting platform.

[0020] A control method according to the low-loss rapeseed harvesting platform comprises the following steps:

[0021] The falling grain detection sensor detects the falling grain loss signal during the feeding process of the header, i.e., the header loss amount, and transmits it to the control unit; the torque sensor detects the torque signal of the header drive shaft and transmits it to the control unit, and the control unit calculates the feeding amount;

[0022] The control unit uses a fuzzy PID-based adaptive sliding mode control algorithm to adjust the wind speed of the duckbill nozzle by controlling the speed of the brushless fan according to the header loss and feed amount, and controls the duckbill nozzle to rotate up and down to adjust the injection angle through the steering gear connecting rod.

[0023] In the above scheme, the control unit adopts an adaptive sliding mode control algorithm based on fuzzy PID, which specifically includes the following steps:

[0024] Step 1: The control unit obtains the header loss L and feed amount Q in real time through the header loss and feed amount, and constructs a multi-input state vector

[0025] Matrix parameters:

[0026] u=[θn] T ;

[0027] Where: θ is the duckbill nozzle angle, n is the fan speed;

[0028] Step 2: Set the target value Q of the feed amount d , the target value of header loss L d , get the current feeding amount error value e Q , header loss error value e L , substitute the error value into the adaptive sliding surface,

[0029] Among them: e Q =QQ d ,e L =LL d , K p , K i , K d is the fuzzy PID parameter;

[0030] Step 3: Design a hybrid fuzzy rule base for coupling feed quantity Q and loss rate L, and dynamically adjust the sliding surface parameter K p , K i , K d ;

[0031] Step 4: Defuzzify by centroid method and get the corresponding The formula is as follows:

[0032]

[0033] Where: ΔK is the final correction value, which is the precise control correction value output by the fuzzy inference system;

[0034] μ i is the membership degree of the i-th rule, representing the activation degree of the i-th fuzzy rule by the current input state;

[0035] ΔK i is the correction value of the i-th rule, which is the control correction amount output by a single fuzzy rule;

[0036] Step 5: Design the switching control law u=u based on the sliding surface S eq +u sw , the defuzzified fuzzy PID parameter K p , K i , K d Substitute the switching control law u=u eq +u sw , get the control quantity u, where the equivalent control u eq Determined by the fuzzy PID output, the switching control u sw Use saturation function to suppress system chattering;

[0037]

[0038] in B + is the pseudo-inverse matrix;

[0039] The control law u is mapped to the jet angle θ of the duckbill nozzle and the speed n of the brushless fan. The servo is controlled to adjust the nozzle angle θ, and the driver is controlled to adjust the speed n of the brushless fan.

[0040] The sliding surface is designed to meet the Lyapunov stability condition, and the switching control u sw Use saturation function to suppress system chattering,

[0041] u sw =-K sw sat(s / φ)

[0042]

[0043] Where φ is the boundary layer thickness, and its value is optimized based on experimental data to balance the response speed and system buffeting;

[0044] The fuzzy reasoner of the adaptive sliding mode control algorithm based on fuzzy PID is a coupled fuzzy rule base of feed quantity Q and loss rate L, which dynamically adjusts the sliding surface parameter K p ,K i ,K d .

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention effectively reduces grain loss through an air-blowing loss reduction device and a control unit. The present invention uses a wind curtain-type airflow to guide the flying grains to the feeding auger inlet. At the same time, the adaptive sliding mode control algorithm based on fuzzy PID adjusts the nozzle spray angle and airflow speed according to the current feed amount and loss amount changes, which can significantly reduce the loss rate of the cutting table and achieve a high-efficiency and low-loss operation effect.

[0047] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above can be clearly seen and extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the main structure of a low-loss rapeseed harvesting platform according to one embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of a top view of a low-loss rapeseed harvesting platform according to one embodiment of the present invention;

[0050] Figure 3 This is a schematic structural diagram of an air blowing loss reduction device according to one embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of the duckbill nozzle and steering gear structure in an air blowing loss reduction device according to one embodiment of the present invention;

[0052] Figure 5 A schematic diagram of a driver according to an embodiment of the present invention;

[0053] Figure 6 A flow chart of a control unit according to an embodiment of the present invention;

[0054] Figure 7 This is a flow chart of a fuzzy PID sliding mode controller according to one embodiment of the present invention;

[0055] Figure 8 FIG. 1 is a schematic diagram of fuzzy control rules according to an embodiment of the present invention.

[0056] In the figure: 1. Air loss reduction device; 101. Torque sensor; 102. Grain falling detection sensor; 103. Duckbill nozzle; 104. Nozzle connector; 105. Air flow hose; 106. Brushless fan; 107. Fan bracket; 108. Wind speed control box; 109. Servo connecting rod; 110. Servo; 111. Servo bracket; 2. Crosscut knife; 3. Stranding chain; 4. Feeding auger; 5. Cutting table frame; 6. Middle straw divider; 601. Stranding head; 602. Middle part of straw divider; 7. Anti-grass entanglement guard; 8. Control unit; 801. Driver; 802. Wind speed sensor; 9. Cutting table drive shaft. DETAILED DESCRIPTION

[0057] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0058] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] Figure 1-6 The figure shows a preferred embodiment of the low-loss rapeseed cutting platform, which includes an air-blowing loss reduction device 1 and a control unit 8;

[0061] The air blowing loss reduction device 1 includes a duckbill nozzle 103, a nozzle joint 104, an air flow hose 105, a brushless fan 106, a fan bracket 107, a wind speed control box 108, a steering gear 110, a torque sensor 101 and a grain falling detection sensor 102; the duckbill nozzle 103 is connected to the vertical surface of the back of the dividing head 601 of the intermediate grain divider 6 through the nozzle joint 104, pointing to the inlet direction of the feeding auger 4, and the air flow can change the movement trajectory of the flying grains, better blow the flying grains into the feeding auger 4, and reduce the grain harvest loss caused by the grain chain 3 hitting the crop stems; the steering gear 110 is connected to the duckbill nozzle 103, and the steering gear 110 is used to drive The dynamic duckbill nozzle 103 rotates up and down; the servo 110 is mounted on the servo bracket 111 and fixed to the crop divider head 601 by bolts; the brushless fan 106 is mounted on the crop divider head 601 through the fan bracket 107 and is connected to the duckbill nozzle 103 through the air flow hose 105; the wind speed control box 108 is connected to the brushless fan 106; the grain loss detection sensor 102 is mounted in the middle part 602 of the crop divider of the intermediate crop divider 6, and is used to detect the grain loss signal during the feeding process of the header and transmit it to the control unit 8; the torque sensor 101 is mounted on the header drive shaft 9, and is used to detect the torque signal of the header drive shaft 9 and transmit it to the control unit 8;

[0062] The control unit 8 is connected to the torque sensor 101, the particle detection sensor 102, the wind speed control box 108 and the steering gear 110 respectively. According to the signals collected by the particle detection sensor 102 and the torque sensor 101, the fuzzy PID sliding mode control algorithm is used to adjust the wind speed of the duckbill nozzle 103 by controlling the speed of the brushless fan 106. The steering gear 110 controls the duckbill nozzle 103 to rotate up and down to adjust the spray angle. Figure 2 shown.

[0063] The straw-dividing head 601 is a triangular cone structure, with its tip facing the working direction to separate the straw. A through hole is provided on the vertical surface of the back for installing the duckbill nozzle 103, and the inner wall of the through hole is provided with an anti-wear coating.

[0064] Installation of the crop divider: Connect the crop divider head 601 and the crop divider middle part 602 by bolts to form the middle crop divider 6. The inner wall of the bolt hole is coated with an anti-wear coating. In a specific embodiment of the present invention, the crop divider 6 has a crop width of 300 mm.

[0065] The side of the nozzle joint 104 is provided with a threaded through hole, one side is connected to the air flow hose 105 through a quick joint, and the other side is fixed with the duckbill nozzle 103 through a detachable interface. The servo 110 is installed on the head 601 of the divider through the servo bracket 111. The servo 110 is connected to the duckbill nozzle 103 through the servo connecting rod 109 to control the duckbill nozzle 103 to rotate up and down to adjust the spray angle; the spray angle adjustment range of the duckbill nozzle 103 is 0°~45°.

[0066] The air flow hose 105 is a corrugated silicone tube. Preferably, the air flow hose 105 has an inner diameter of 30 mm and a pressure resistance range of -10kPa to +50kPa. One end of the air flow hose 105 is sealed to the air outlet of the brushless fan 106, and the other end is sealed to the air inlet of the duckbill nozzle 103.

[0067] The brushless fan 106 is connected to the wind speed control box 108 through the driver 801. The driver 801 receives the PWM signal of the wind speed control box 108 and adjusts the speed of the brushless fan 106 in real time. A wind speed sensor 802 is provided in the duckbill nozzle 103. The wind speed sensor 802 is used to detect the wind speed in the duckbill nozzle 103 and transmit it to the control unit 8.

[0068] The blades of the brushless fan 106 are backward-inclined centrifugal impellers with a diameter of 120 mm, a rated speed of 2000 to 50000 r / min, and a maximum air volume of 60 m 3 / min; Driver 801 has a built-in overload protection module, which automatically reduces the speed and issues an alarm when the motor current exceeds the threshold;

[0069] The brushless fan 106 is installed inside the crop divider head 601 through a fan bracket 107 and does not interfere with the crop chain 3. The fan bracket 107 is a metal grid heat dissipation structure, which reduces the temperature of the fan when it is running for a long time through the grid heat dissipation.

[0070] The bottom of the cutting platform frame 5 is provided with an anti-grass entanglement guard plate 7, and the anti-grass entanglement guard plate 7 covers the crosscutting knife 2 and keeps a gap with the reed chain 3. The surface of the anti-grass entanglement guard plate 7 is coated with hydrophobic material.

[0071] The outlet end of the duckbill nozzle 103 is a duckbill-shaped flat structure, and the ejected airflow is fan-shaped with a fan-shaped coverage angle of 30° to 60°. The fan-shaped airflow coverage surface is designed to form a wind curtain, and the cutting platform is covered by multiple duckbill nozzles 103. The coverage width is 1.2 to 1.5 times the inlet width of the feeding auger 4. During the process of the straw chain 3 feeding the stalks, the wind curtain blows the rapeseed grains with exploded pods into the feeding auger 4, reducing the splashing loss of the rapeseed grains and improving the airflow guidance efficiency in the fallen grain recovery chamber.

[0072] In a specific embodiment of the present invention, the outlet width of the duckbill nozzle 103 is 50 mm, and the coverage width is 1.3 times the inlet width of the feed auger 4; the fan-shaped coverage angle is 45°, ensuring that the airflow evenly covers the falling grain area. The spray angle adjustment range of the duckbill nozzle 103 is 12°, the speed of the brushless fan 106 is 20,000 rpm, and the angle is adjusted by the servo 110 (the angle accuracy is 0.5° and the repeatability accuracy is ±0.5%); the rated speed of the brushless fan 106 is 50,000 r / min, and the maximum air volume is 60m 3 / min; the brushless fan 106 is installed through the fan bracket 107, and the fan bracket 107 is an elastic shock-absorbing structure (rubber cushion thickness 8mm + metal spring stiffness 20N / mm), which reduces the vibration amplitude by 60%; the air flow hose 105 is made of corrugated silicone tube with an inner diameter of 30mm, a pressure resistance of -10kPa to +50kPa, and a loss rate of ≤1.2%.

[0073] In a specific embodiment of the present invention, the particle falling detection sensor 102 is a photoelectric particle counter; the sampling frequency is set to 100 Hz, and the header loss amount signal is transmitted to the control unit 8 via the CAN bus;

[0074] In a specific embodiment of the present invention, the torque sensor 101 is a strain gauge torque sensor with a measuring range of 0 to 500 N·m. The feed amount is indirectly obtained by calculating the torque value, and the formula is:

[0075]

[0076] Where τ(t) is the real-time torque (N·m), n is the transmission shaft speed (r / min), and Q(t) is the feed rate (kg / s)

[0077] The angle of the duckbill nozzle 103 is adjusted by a servo 110 (angle accuracy 0.5°), with a maximum adjustment angle of ±45°, a repeat positioning accuracy of ±0.5°, and a response time of ≤30ms.

[0078] The speed regulation of the brushless fan 106 is realized by receiving a PWM signal through the driver, with a wind speed range of 3 to 40 m / s and an adjustment error of <±1%. The linear correspondence wind speed is 3 to 40 m / s. The built-in wind speed sensor 802 performs closed-loop feedback and the adjustment error is <±1%.

[0079] In one embodiment of the present invention, control unit 8 utilizes an ARM Cortex-M7 chip, supports multi-channel ADC / DAC and CAN bus communication, implements real-time operating system (RTOS) task scheduling, prioritizes tasks to ensure a control cycle of ≤10ms, and implements a fuzzy PID sliding mode control algorithm with a boundary layer thickness of φ = 0.1. A servo 110 (with an angle accuracy of 0.5°) drives the angle adjustment of the duckbill nozzle 103, while a driver 801 controls the speed of the brushless fan 106.

[0080] Working principle: When using the rapeseed harvesting platform air-blowing loss reduction device, first install the rapeseed harvesting platform air-blowing loss reduction device 1 on the rapeseed harvester, and make the harvester perform harvesting operations in the rapeseed field. In the process of harvesting rapeseed grains, the straw chain 3 feeds the rapeseed stalks. In this process, the splashing rapeseed grains enter the middle part 602 of the straw divider under the combined action of gravity and forward airflow. At the same time, the fan 106 is running, and the duckbill nozzle 103 generates a wind curtain through the airflow hose 105, blowing the splashed grains into the feeding auger 4. The control unit 8 adopts a sliding mode control algorithm based on fuzzy PID to dynamically adjust the wind speed of the duckbill nozzle 103 by controlling the speed of the brushless fan 106 according to the harvesting platform loss and the feeding amount, and dynamically adjusts the spray angle by controlling the duckbill nozzle 103 to rotate up and down through the servo 110. By designing the sliding surface

[0081] Ensure system stability and verify it through Lyapunov function.

[0082] A harvester, comprising the low-loss rapeseed header and a header frame 5, the header frame 5 is fixed to the harvester body, ensuring that the feeding auger 4 is arranged centrally along the longitudinal axis, such as Figure 1 shown.

[0083] A control method according to the low-loss rapeseed harvesting platform comprises the following steps:

[0084] The falling grain detection sensor 102 detects the falling grain loss signal during the header feeding process, i.e., the header loss amount, and transmits it to the control unit 8; the torque sensor 101 detects the torque signal of the header drive shaft 9 and transmits it to the control unit 8, and the control unit 8 calculates the feeding amount;

[0085] The control unit 8 uses a fuzzy PID-based sliding mode control algorithm to adjust the wind speed of the duckbill nozzle 103 by controlling the speed of the brushless fan 106 according to the header loss and feed amount, and controls the duckbill nozzle 103 to rotate up and down to adjust the injection angle through the servo 110.

[0086] The control unit 8 adopts a sliding mode control algorithm based on fuzzy PID. The input of the fuzzy PID sliding mode control algorithm is the header loss L and the feed amount Q. The output is the injection angle θ of the duckbill nozzle 103 and the speed n of the brushless fan 106. The algorithm processes the two inputs and generates the corresponding output. Then, the sliding surface is designed by combining the integral and differential of the error and the feed amount change rate. The stability of the sliding surface is verified by the Lyapunov function. Next, the fuzzy inference device is designed to set the header loss L target value L d , feed quantity target value Q d , the input is processed into the header loss error value e L And the feeding amount error value e Q , define the input variable e L and e Q The membership function and the output variable K p , K i , K d A membership function was established, and a fuzzy rule base was established to cover all possible input combinations. Furthermore, a control law was designed, using a saturation function instead of a traditional sign function to reduce chattering caused by high-profile switching. Parameters were optimized through experiments to balance response speed and chatter suppression. Fuzzy rules were stored in the controller using a lookup table, reducing online computation and ensuring fast control system response. Finally, the control law was used to map the controlled variable to the output variable.

[0087] The specific steps include:

[0088] Step 1: The control unit 8 obtains the header loss L and feed amount Q in real time through the grain loss sensor and torque sensor, and substitutes them into the multi-input state equation

[0089] Matrix parameters:

[0090] u=[θn] T ;

[0091] Where: θ is the duckbill nozzle angle, n is the fan speed;

[0092] Calibrate the parameters in the state matrix through experiments. For matrix A:

[0093] a 21 Q is the feed rate The inertial damping reflects the change of the inertial resistance of the header mechanical system:

[0094]

[0095] where k f is the mechanical friction coefficient of the auger,

[0096] J is the moment of inertia of the auger,

[0097] ρ is the rapeseed crop density;

[0098] a 22 Feed rate change The self-damping coefficient reflects the fluid damping efficiency during stalk transportation:

[0099]

[0100] Among them, C d is the air resistance coefficient,

[0101] η air is the air viscosity,

[0102] A duct is the cross-sectional area of ​​the air flow duct,

[0103] m eq is the equivalent transport mass;

[0104] a 23 is the loss rate L versus feed change rate Interference gain:

[0105]

[0106] Among them, α is the flow field interference factor,

[0107] σ(L) is the probability function of kernel escape;

[0108] a 41 The change rate of feed Q to loss rate The induced gain:

[0109]

[0110] Where β is the impact sensitivity coefficient,

[0111] w is the moisture content of the grain,

[0112] is the number of grain collisions per unit time,

[0113] A area The working area of ​​the header;

[0114] a 43 is the loss rate L to its own change rate The cumulative effect of:

[0115]

[0116] Where γ is the loss cumulative gain,

[0117] λ is the Sigmoid steepness coefficient,

[0118] L c is the critical loss rate;

[0119] a 44 Loss rate change rate The self-attenuation coefficient reflects the negative feedback effect of the air blowing loss reduction device:

[0120]

[0121] Among them, k v For wind speed control efficiency,

[0122] v max is the maximum effective wind speed,

[0123] τ fan is the fan response time constant;

[0124] For matrix B:

[0125] b 11 The change rate of nozzle angle θ to feed amount Gain:

[0126]

[0127] k θ is the mechanical efficiency coefficient,

[0128] P air is the airflow pressure distribution function,

[0129] ρ is the rapeseed crop density;

[0130] b 12 is the change rate of fan speed n to feed amount Gain:

[0131]

[0132] Among them, k v is the wind speed-rotation speed conversion coefficient,

[0133] A duct is the cross-sectional area of ​​the air flow duct,

[0134] η convey For transport efficiency,

[0135] n max is the maximum speed of the fan,

[0136] b 21 is the derivative of the nozzle angle θ with respect to the loss rate Gain:

[0137]

[0138] Among them, k L : is the loss suppression coefficient,

[0139] α escape is the grain escape angle function,

[0140] w is the moisture content of the grain;

[0141] b 22 is the derivative of the fan speed n with respect to the loss rate Gain:

[0142]

[0143] Where β is the airflow attenuation coefficient,

[0144] v crit is the critical wind speed for grain suspension,

[0145] C d is the resistance coefficient of the grain;

[0146] Q d is the set value, Q d =5kg / s; L d is the set value, L d Stable below 2%;

[0147] Step 2: Set the header loss target value L in the controller d , feed quantity target value Q d ,

[0148] The control unit 8 processes the real-time data and obtains the header loss error value e L And the feeding amount error value e Q , substitute the error value into the adaptive sliding surface, sliding surface equation:

[0149]

[0150] Among them, e Q =QQ d ;e L =LL d ;K p， K i， K d is the fuzzy PID parameter;

[0151] Step 3: Substitute the parameters into the hybrid fuzzy reasoner of feed amount Q and loss rate L. The fuzzy rule base has 25 core rules, covering all working conditions. The rule base makes joint decisions through 5 input dimensions and dynamically adjusts the sliding surface parameter K. p , Ki , K d To achieve precise control;

[0152] Step 4: Defuzzify the fuzzy PID parameters output by the fuzzy inference engine by the centroid method. The formula is as follows to obtain the corresponding

[0153]

[0154] Where: ΔK is the final correction value, which is the precise control correction value output by the fuzzy inference system;

[0155] μ i is the membership degree of the i-th rule, representing the activation degree of the i-th fuzzy rule by the current input state;

[0156] ΔK i is the correction value of the i-th rule, which is the control correction amount output by a single fuzzy rule;

[0157] Step 5: The defuzzified fuzzy PID parameter K p ,K i ,K d Substitute the switching control law u=u eq +u sw , get the equivalent control value u of the control quantity u eq and switching control value u sw , where the equivalent control u eq Determined by the fuzzy PID output, the switching control u sw Use saturation function to suppress system chattering;

[0158]

[0159] in B + is the pseudo-inverse matrix,

[0160] u sw =-K sw sat(s / φ)

[0161]

[0162] Where: φ is the boundary layer thickness, which is optimized based on experimental data to balance response speed and system buffeting;

[0163] The saturation function sat(z) is defined as:

[0164]

[0165] Step 6: Map the control law u to the injection angle θ of the duckbill nozzle 103 and the speed n of the brushless fan 106 , control the servo 110 to adjust the nozzle angle θ, and control the driver 801 to adjust the speed n of the brushless fan 106 , with a response time of ≤50ms;

[0166] As shown in Table 1, the fuzzy reasoner is a coupled fuzzy rule base of feed quantity Q and loss rate L, with a total of 25 core rules covering all working conditions. The rule base makes joint decisions through 5 input dimensions and dynamically adjusts the sliding surface parameter K. p ,K i ,K d To achieve precise control.

[0167] like Figure 7 As shown in the figure, this is the system block diagram of the adaptive sliding mode controller based on fuzzy PID, where X is the system input matrix, is the derivative of x with respect to time, substitute the equivalent control value u eq Calculate the input matrix u; e Q and e L is the error value calculated based on the set value; ∫ is the integral of time; is the parameter calculated by the fuzzy inference device; u is the controller input matrix, u=[θn] T The controller combines fuzzy PID and sliding mode control (SMC). Fuzzy rules are used to dynamically adjust the PID parameters of the equivalent control part of the sliding mode control to improve the adaptability and robustness of the system under uncertain disturbances. At the same time, the switching term of the sliding mode control ensures the robustness and convergence of the system.

[0168] In one embodiment of the present invention,

[0169] Fuzzy inference input variables include:

[0170]

[0171]

[0172] The output fuzzy variable set is defined as follows:

[0173]

[0174]

[0175] Control law implementation:

[0176] Through field experiments, the parameters in the state equation are calibrated:

[0177] Step 1: The control unit 8 obtains the header loss L and feed amount Q in real time through the grain loss sensor and torque sensor, and substitutes them into the multi-input state equation

[0178] Matrix parameters:

[0179] u=[θn] T ;

[0180] Where: θ is the duckbill nozzle angle, n is the fan speed.

[0181] For matrix A:

[0182] a 21 Q is the feed rate The inertial damping reflects the change of the inertial resistance of the header mechanical system:

[0183]

[0184] Where: k f is the mechanical friction coefficient of the auger, the measured value = 0.85N·s 2 / kg;

[0185] J is the moment of inertia of the auger, typical value = 0.12kg·m 2 ;

[0186] ρ is the rapeseed crop density, measured value = 3.3 kg / m2;

[0187] Calibration value: a 21 =-0.18s -2 ;

[0188] a 22 Feed rate change The self-damping coefficient reflects the fluid damping effect during stalk transportation:

[0189]

[0190] Where: C d is the air resistance coefficient, set value = 0.3;

[0191] η air is the air viscosity, set value = 1.8×10 - 5Pa·s;

[0192] A duct is the cross-sectional area of ​​the airflow duct, actual value = 0.05m 2 ;

[0193] m eq is the equivalent transport mass, m eq=QΔt;

[0194] Calibration value; a 22 =-0.25s -1 ;

[0195] a 23 : Loss rate L versus feed change rate Interference gain;

[0196]

[0197] α is the flow field interference factor, set value = 0.15;

[0198] σ(L) is the probability function of kernel escape, σ=1-e -kL ,k=8.0;

[0199] Calibration value: a 23 =-0.06s -2 % -1

[0200] a 41 The change rate of feed Q to loss rate The induced gain:

[0201]

[0202] β is the impact sensitivity coefficient, set value = 0.05;

[0203] w is the moisture content of the grain, the measured value = 21%;

[0204] is the number of kernel collisions per unit time, which is positively correlated with the feed amount;

[0205] A area The actual operating area of ​​the header is 2.2m. 2 ;

[0206] Calibration value: a 41 =0.09%\cdotps -2 (kg / s) -1 ;

[0207] a 43 is the loss rate L to its own change rate The cumulative effect of:

[0208]

[0209] Where γ is the loss accumulation gain, and its setting value is 1.2;

[0210] λ is the steepness coefficient, set value = 0.8;

[0211] L c is the critical loss rate, set value = 2%;

[0212] Calibration value: a 43 =0.15%\cdotps -2 % -1 ;

[0213] a 44 :Loss rate change rate The self-attenuation coefficient reflects the negative feedback effect of the air-blowing loss reduction device;

[0214]

[0215] k v is the wind speed control efficiency, the calibration value = 0.35;

[0216] v max is the maximum effective wind speed, which was measured to be 8m / s;

[0217] τ fan is the fan response time constant, the measured value = 0.2s;

[0218] Calibration value: a 44 =-0.40s -1 ;

[0219] For matrix B:

[0220] b 11 : Nozzle angle θ changes the feed rate Gain;

[0221]

[0222] k θ is the mechanical efficiency coefficient, the measured value = 0.85;

[0223] P air is the airflow pressure distribution function, the typical model is P air = sin(2θ); ρ is the rapeseed plant density, measured value = 3.3 kg / m 2

[0224] Calibration value: b 11 =0.03kg\cdotps -2 ·rad -1

[0225] b 12 : Fan speed n versus feed rate change Gain;

[0226]

[0227] k v is the wind speed-rotation speed conversion coefficient, set v = 0.02n, unit is m / s)A duct is the cross-sectional area of ​​the airflow duct, actual value = 0.05m 2 ;

[0228] η convey is the conveying efficiency, set value = 0.75;

[0229] n max The maximum speed of the fan, actual value = 50000rpm;

[0230] Calibration value: b 12 =0.02kg\cdotps -2 ·rpm -1 ;

[0231] b 21 : Derivative of nozzle angle θ on loss rate Gain;

[0232]

[0233] k L : Loss suppression coefficient, set value = 1.2;

[0234] α escape is the grain escape angle function, w: grain moisture content, measured value = 21%;

[0235] Calibration value: b 21 =-0.10%·s -2 ·rad -1 ;

[0236] b 22 : Derivative of fan speed n with respect to loss rate Gain;

[0237]

[0238] β: airflow attenuation coefficient (≈0.4)

[0239] v crit : Critical wind speed for grain suspension (typical value 5.2m / s)

[0240] C d : Grain resistance coefficient (≈0.8)

[0241] Calibration value: b 22 =-0.15%·s -2 ·rpm -1

[0242] Step 2: Set the header loss target value L in the control unit 8 d ,

[0243] L d =1%

[0244] Set the feed target value Q d ,

[0245] Q d =5kg / s

[0246] The control unit 8 processes the real-time data and obtains the header loss error value e L And the feeding amount error value e Q , substitute the error value into the adaptive sliding surface, sliding surface equation:

[0247]

[0248] Among them, e Q =QQ d ;e L =LL d ;K p， K i， K d is the fuzzy PID parameter;

[0249] Step 3: The control unit 8 substitutes the error value and its derivative into the fuzzy inference device and outputs the corresponding fuzzy PID parameters. Then the parameters are defuzzified to obtain the corresponding

[0250] Step 4: The defuzzified fuzzy PID parameter K p , K i , K d Substitute the switching control law u=u eq +u sw , get the control quantity u, where the equivalent control u eq Determined by the fuzzy PID output, the switching control u sw Use saturation function to suppress system chattering;

[0251]

[0252] in B + is the pseudo-inverse matrix;

[0253] u sw =-K sw sat(s / φ)

[0254]

[0255] Where: φ is the boundary layer thickness, set to 0.02, which can be optimized based on experimental data to balance response speed and system buffeting;

[0256] The saturation function sat(z) is defined as:

[0257]

[0258] After the above steps, the corresponding nozzle angle θ and brushless motor speed n are obtained.

[0259] Step 5: Control Volume Mapping

[0260] The formula for nozzle angle θ is: θ(t) = k θ u(t)

[0261] where k θ =0.5° / V, corresponding to the control range of -10V to +10V.

[0262] The mapping relationship between the speed of the brushless motor 106 and the control amount is:

[0263] n(t)=kn·u(t)

[0264] Where, kn = 1040 rpm / V, which represents the speed gain coefficient;

[0265] u(t) is the voltage signal output by the controller, ranging from 0 to 48V;

[0266] The corresponding speed range of the brushless motor 106 is 0 to 50,000 rpm (calculated value: 48V×1040 rpm / V=49,920 rpm), and the actual operating range is limited to 2000 to 40,000 rpm to adapt to the rated working conditions of the brushless motor 106 .

[0267] The present invention effectively reduces grain loss through an air-blowing loss reduction device 1 and a control unit 8. The present invention utilizes a curtain-like airflow to direct splashing grains toward the feed auger inlet. Simultaneously, an adaptive sliding mode control algorithm based on fuzzy PID adjusts the nozzle spray angle and airflow velocity according to changes in the current feed volume and loss volume. During operation, the grain drop detection sensor 102 and the torque sensor 101 continuously monitor the operation status of the harvesting platform. The control unit 8 calculates the optimal control parameters based on the collected data. The servo 110 drives the duckbill nozzle 103 to adjust to the optimal angle, and the brushless fan 106 synchronously generates a stable directional airflow. Actual applications have shown that this technology can significantly reduce the harvesting platform loss rate. It is not only suitable for conventional rapeseed harvesting, but also has excellent adaptability to lodging rapeseed and other small-seed crops, achieving high efficiency and low-loss operations.

[0268] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0269] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0270] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A low-loss rapeseed harvesting platform, characterized in that: It comprises an air blowing loss reduction device (1) and a control unit (8); The air blowing loss reduction device (1) comprises a duckbill nozzle (103), a nozzle connector (104), an air flow hose (105), a brushless fan (106), a fan bracket (107), a wind speed control box (108), a steering gear (110), a torque sensor (101) and a grain falling detection sensor (102); the duckbill nozzle (103) is connected to the vertical surface of the back of the grain dividing head (601) of the intermediate grain divider (6) through the nozzle connector (104), pointing to the direction of the feeding auger (4) inlet; the steering gear (110) is connected to the duckbill nozzle (103), and the steering gear (110) is used to drive the duckbill nozzle (103) ) rotates up and down; the brushless fan (106) is installed on the grass dividing head (601) through the fan bracket (107) and is connected to the duckbill nozzle (103) through the air flow hose (105); the wind speed control box (108) is connected to the brushless fan (106); the grain loss detection sensor (102) is installed in the middle part (602) of the grass divider (6) of the middle grass divider, and is used to detect the grain loss signal during the feeding process of the cutting platform and transmit it to the control unit (8); the torque sensor (101) is installed on the cutting platform transmission shaft (9), and is used to detect the torque signal of the cutting platform transmission shaft (9) and transmit it to the control unit (8); The control unit (8) is respectively connected to a torque sensor (101), a particle falling detection sensor (102), a wind speed control box (108) and a steering gear (110). Based on signals collected by the particle falling detection sensor (102) and the torque sensor (101), the wind speed of the duckbill nozzle (103) is adjusted by controlling the rotation speed of the brushless fan (106). The steering gear (110) controls the duckbill nozzle (103) to rotate up and down to adjust the spray angle.

2. The low-loss rapeseed harvesting platform according to claim 1, characterized in that: The straw-dividing head (601) is a triangular pyramidal structure, with its tip facing the working direction to separate the straw. A through hole is provided on the vertical surface of the back for installing a duckbill nozzle (103), and the inner wall of the through hole is provided with an anti-wear coating.

3. The low-loss rapeseed harvesting platform according to claim 1, characterized in that: The nozzle joint (104) is provided with a threaded through hole on its side, one side of which is connected to an air flow hose (105) via a quick joint, and the other side of which is fixed to a duckbill nozzle (103) via a detachable interface. A steering gear (110) is installed on the head of the crop divider (601) via a steering gear bracket (111). The steering gear (110) is connected to the duckbill nozzle (103) via a steering gear connecting rod (109) to control the duckbill nozzle (103) to rotate up and down to adjust the spray angle; the duckbill nozzle (103) has an adjustment range of an up and down spray angle of 0° to 45°.

4. The low-loss rapeseed harvesting platform according to claim 1, characterized in that: The air flow hose (105) is a corrugated silicone tube, one end of the air flow hose (105) is sealed connected to the air outlet of the brushless fan (106), and the other end is sealed connected to the air inlet of the duckbill nozzle (103).

5. The low-loss rapeseed harvesting platform according to claim 1, characterized in that: The brushless fan (106) is connected to the wind speed control box (108) via a driver (801), and the driver (801) receives a PWM signal from the wind speed control box (108) to adjust the speed of the brushless fan (106) in real time; a wind speed sensor (802) is provided in the duckbill nozzle (103), and the wind speed sensor (802) is used to detect the wind speed in the duckbill nozzle (103) and transmit the wind speed to the control unit (8); The blades of the brushless fan (106) are backward-inclined centrifugal impellers, and the driver (801) has a built-in overload protection module, which automatically reduces the speed and issues an alarm when the motor current exceeds a threshold.

6. The low-loss rapeseed harvesting platform according to claim 1, characterized in that: The bottom of the cutting platform frame (5) is provided with an anti-grass entanglement guard plate (7), and the anti-grass entanglement guard plate (7) covers the cross-cutting knife (2) and maintains a gap with the reed chain (3), and the surface of the anti-grass entanglement guard plate (7) is coated with a hydrophobic material.

7. The low-loss rapeseed harvesting platform according to claim 1, characterized in that: The outlet end of the duckbill nozzle (103) is a duckbill-shaped flat structure, and the ejected airflow is fan-shaped, with a fan-shaped coverage angle of 30° to 60°. The fan-shaped coverage forms an air curtain, and the cutting platform is covered by multiple duckbill nozzles (103), and the coverage width is 1.2 to 1.5 times the inlet width of the feeding auger (4).

8. A harvester, characterized in that: The invention comprises the low-loss rapeseed harvesting platform described in any one of claims 1 to 7.

9. A control method for a low-loss rapeseed header according to any one of claims 1 to 7, characterized in that: The following steps are involved: The falling grain detection sensor (102) detects the falling grain loss signal during the feeding process of the cutting table, i.e., the cutting table loss amount, and transmits it to the control unit (8); the torque sensor (101) detects the torque signal of the cutting table transmission shaft (9) and transmits it to the control unit (8), and the control unit (8) calculates the feeding amount; The control unit (8) uses a fuzzy PID-based sliding mode control algorithm to adjust the wind speed of the duckbill nozzle (103) by controlling the rotation speed of the brushless fan (106) according to the loss amount of the cutting platform and the feed amount, and controls the duckbill nozzle (103) to rotate up and down to adjust the injection angle through the steering gear connecting rod (109).

10. The control method of the low-loss rapeseed header according to claim 9, characterized in that: The control unit (8) adopts an adaptive sliding mode control algorithm based on fuzzy PID, which specifically includes the following steps: Step 1: The control unit (8) obtains the header loss L and feed amount Q in real time through the header loss and feed amount, and constructs a multi-input state vector Matrix parameters: u=[θn] T ; in: θ is the jet angle of the duckbill nozzle; n is the fan speed; Step 2: Set the target value Q of the feed amount d , the target value of header loss L d , get the current feeding amount error value e Q , header loss error value e L , substitute the error value into the adaptive sliding surface, Sliding surface Among them: e Q =QQ d ,e L =LL d , K p , K i , K d is the fuzzy PID parameter; Step 3: Design a hybrid fuzzy rule base for coupling feed quantity Q and loss rate L, and dynamically adjust the sliding surface parameter K p , K i , K d ; Step 4: Defuzzify by centroid method. The formula is as follows to get the corresponding Where: ΔK is the final correction value, which is the precise control correction value output by the fuzzy inference system; μ i is the membership degree of the i-th rule, representing the activation degree of the i-th fuzzy rule by the current input state; ΔK i is the correction value of the i-th rule, which is the control correction amount output by a single fuzzy rule; Step 5: Design the switching control law u=u based on the sliding surface S eq +u sw , the defuzzified fuzzy PID parameter K p , K i , K d Substitute the switching control law u=u eq +u sw , get the control quantity u, where the equivalent control u eq Determined by the fuzzy PID output, the switching control u sw Use saturation function to suppress system chattering; in B + is the pseudo-inverse matrix; The control law u is mapped to the injection angle θ of the duckbill nozzle (103) and the speed n of the brushless fan (106), the steering gear (110) adjusts the nozzle angle θ, and the driver (801) adjusts the speed n of the brushless fan (106); The sliding surface is designed to meet the Lyapunov stability condition, and the switching control u sw Use saturation function to suppress system chattering, u sw =-K sw sat(s / φ) Where φ is the boundary layer thickness, and its value is optimized based on experimental data to balance the response speed and system buffeting; The fuzzy reasoner of the adaptive sliding mode control algorithm based on fuzzy PID is a coupled fuzzy rule base of feed quantity Q and loss rate L, which dynamically adjusts the sliding surface parameter K p ,K i ,K d .

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