Independent header adaptive profiling control system based on multi-sensor fusion

Abstract

The invention belongs to the technical field of combine harvesters, and discloses an independent header adaptive profiling control system based on multi-sensor fusion, which comprises a sensing module, an execution module and a control module, and is characterized in that the sensing module and the execution module are electrically connected with the control module; the sensing module comprises high-precision angle sensors installed on the left side and the right side of the header, and each high-precision angle sensor is hinged to the header through a mechanical rotating arm and a tension spring assembly and used for converting the vertical displacement and the inclination angle of the header relative to the ground into electric signals. Through deep cooperation of sensing, execution and control technologies, the crop loss rate is reduced by 30%-50%, the impurity rate is remarkably reduced, the method is particularly suitable for low-stubble harvesting operation of soybeans, oilseed rapes and the like, the operation quality and economic benefits of a combine harvester are greatly improved, and agricultural machinery equipment is promoted to be upgraded to high-end intelligence.

Description

Technical Field

[0001] This invention belongs to the field of combine harvester technology, and particularly relates to an independent header adaptive contour control system based on multi-sensor fusion. Background Technology

[0002] The header contouring technology of combine harvesters is a core component of intelligent harvesting technology, directly impacting harvest quality and economic benefits. Traditional combine harvester header contouring technology has evolved through stages: mechanical contouring, semi-automatic contouring, and finally, intelligent adaptive contouring. Early mechanical contouring relied on linkage mechanisms to achieve passive ground-hugging operation, resulting in low contouring accuracy. Semi-automatic contouring used hydraulic systems to drive header lifting and lowering, but its response was slow, requiring frequent operator intervention. While current intelligent contouring technology has achieved a degree of automatic control, it still has many shortcomings.

[0003] In terms of mechanical sensing, existing systems mostly use a configuration of "mechanical slippers + single-sided angle sensors," which can only acquire single-point or single-sided terrain information and cannot capture the overall three-dimensional posture of the header. This results in blind spots in laterally undulating terrain, leading to header tilting causing missed cuts or the harvester "digging holes," resulting in high crop loss rates. Regarding hydraulic actuation, conventional systems use on / off solenoid valves or simple proportional valves. The header's lifting and lowering movements are impactful and uncontrollable in speed, lacking effective locking and synchronization mechanisms. The header is prone to "sinking" and drifting, and asynchronous movements of multiple cylinders can cause twisting and jamming. In terms of electronic control decision-making, the mainstream control strategy is single PID real-time feedback control, a "passive reaction" mode. The system response time is often greater than 1 second, and the header is constantly "chasing" terrain changes, resulting in large control errors and failing to meet high-standard operational requirements.

[0004] Therefore, there is an urgent need to develop a cutting platform adaptive contour control system that can achieve accurate perception of the entire terrain, improve the stability and dynamic accuracy of the actuator, and have forward-looking intelligent control capabilities, in order to solve the above-mentioned problems existing in the current technology. Summary of the Invention

[0005] The technical problem this invention aims to solve is the industry challenge of high header loss and high impurity content when combine harvesters operate on complex and uneven terrain.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows: An independent cutting table adaptive contour control system based on multi-sensor fusion includes a sensing module, an execution module, and a control module, wherein the sensing module and the execution module are electrically connected to the control module respectively; The sensing module includes high-precision angle sensors installed on the left and right sides of the cutting table. Each high-precision angle sensor is hinged to the cutting table via a mechanical rotating arm, a tension spring assembly, and a tension spring assembly, and is used to convert the vertical displacement and tilt angle of the cutting table relative to the ground into electrical signals. The sensing module may also selectively integrate an inertial measurement unit to detect the fuselage attitude and provide auxiliary compensation signals; The execution module is a hydraulic drive system, including an integrated electromagnetic proportional valve group, a single-acting cylinder for lifting the cutting table, a double-acting cylinder for swinging the cutting table, and a hydraulically controlled check valve. The integrated electromagnetic proportional valve group is connected to the single-acting cylinder for lifting the cutting table and the double-acting cylinder for swinging the cutting table through oil circuits, and the hydraulically controlled check valve is integrated into the oil circuits. The control module is a high-performance electronic control unit (ECU). The ECU has a built-in dual-loop intelligent control algorithm of "feedforward prediction + real-time feedback" to receive electrical signals from the sensing module, perform data fusion processing, and output control commands to the execution module. The ECU receives signals from the sensor on the flexible part of the cutter head through the feedforward loop to predict terrain changes, and receives signals from the sensor on the bridge part of the cutter head through the feedback loop to monitor attitude. After calculating and comparing the feedforward prediction and real-time feedback, the ECU dynamically corrects the control commands to achieve precise control of the cutter head attitude.

[0007] Furthermore, the high-precision angle sensor has a signal output range of 0-5V and a detection angle range of 0-180°.

[0008] Furthermore, the lifting speed of the single-acting hydraulic cylinder of the cutting platform is 0.4 m / s, and the lowering speed is 0.32 m / s.

[0009] Furthermore, the synchronization error between the single-acting hydraulic cylinder for lifting the cutting table and the double-acting hydraulic cylinder for swinging the cutting table is ≤5%.

[0010] Furthermore, the locking pressure range of the hydraulic check valve is 20-170 bar, and it has an adaptive pressure adjustment function.

[0011] Furthermore, the system response time of the dual-loop intelligent control algorithm is less than 0.7 seconds.

[0012] Furthermore, the control error between the profile height of the cutting platform and the target height is less than 7 mm.

[0013] Furthermore, the electronic control unit has multi-channel analog / digital input, high-speed CAN bus communication, and high-current drive output capabilities.

[0014] Furthermore, the sensing module also includes a ground pressure sensor, the signal output range of which is 0-5V and the detection pressure range is 0-160BAR.

[0015] Furthermore, the power supply specifications for the solenoid valves of the execution module include DC12V and DC24V, wherein the solenoid valves built into the cutting table are powered by DC12V, and the solenoid valves controlled by the bridge are controlled by DC24V proportional current.

[0016] The present invention has the following advantages: 1. Comprehensive upgrade of perception capabilities: By independently deploying high-precision angle sensors and rotating arm-tension spring assemblies on both sides of the cutting table, a three-dimensional perception network is constructed to achieve full-domain capture of the three-dimensional posture of the cutting table, completely eliminating the lateral contour blind zone, solving the problems of missed cutting and "digging holes" caused by single-point perception in existing technologies, and providing a high-fidelity data foundation for precise control.

[0017] 2. Significantly improved execution accuracy: Adopting a high-performance hydraulic combination of "integrated electromagnetic proportional valve + hydraulic check valve", the system achieves stepless precise control of cylinder speed and reliable position locking. The synchronization error of multi-cylinder actions is ≤5%, and the lifting speed of the cutting table reaches 0.4m / s and 0.32m / s respectively. This effectively solves the defects of existing technologies, such as large impact, poor stability and low synchronization accuracy, and improves the dynamic response and static stability of the actuator.

[0018] 3. Intelligent and forward-looking control strategy: The innovative construction of a dual-loop control architecture of "feedforward prediction + real-time feedback" compresses the system response time to less than 0.7 seconds and the cutting table height control error to less than 7 mm. It breaks through the "lag correction" limitation of traditional single PID control and realizes the leap from "passive reaction" to "forward intelligence", ensuring accurate contouring under complex working conditions.

[0019] 4. Significantly optimized operational performance: Through deep collaboration of sensing, execution, and control technologies, crop loss rate is reduced by 30%-50%, and impurity content is significantly decreased. It is especially suitable for low-stubble harvesting operations such as soybeans and rapeseed, greatly improving the operational quality and economic benefits of combine harvesters and promoting the upgrading of agricultural machinery equipment to high-end intelligence. Attached Figure Description

[0020] Figure 1 Schematic diagram of a high-feed-capacity multi-grain combine harvester crossing a bridge; Figure 2 Schematic diagram of angle sensor 1; Figure 3 Schematic diagram of angle sensor 2; Figure 4 Schematic diagram of an integrated electromagnetic proportional valve assembly; Figure 5 Schematic diagram of a single-acting cylinder for lifting the cutting table; Figure 6 Schematic diagram of the swing-type double-operation cylinder of the cutting table; Figure 7 Electrical control wiring diagram. Detailed Implementation

[0021] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0022] This embodiment features an independent header adaptive contour control system based on multi-sensor fusion, applied to a large-feed multi-grain combine harvester. Its hardware configuration is as follows: The sensing module employs two high-precision angle sensors (model compatible, 0-5V output, 0-180° detection range), installed on the left and right sides of the header respectively, and hinged to the header via a customized rotating arm and tension spring assembly; a ground pressure sensor (0-160BAR detection range) is installed in the header's hydraulic circuit; the execution module uses an integrated electromagnetic proportional valve group (flow rate A=B=50-65L / min), equipped with a single-acting header lifting cylinder (stroke adapted to the harvester model) and a double-acting header swing cylinder; the hydraulic check valve is selected to match a pressure range of 20-170bar; the control module uses a high-performance ECU (with more than 8 analog inputs and a CAN bus communication interface), with built-in dual-loop intelligent control algorithm firmware.

[0023] This system is a typical mechatronics product, and its hardware architecture mainly consists of three modules: 1. Sensing Module: Serving as the system's "sensors," the core consists of high-precision angle sensors mounted on the left and right sides of the cutter head. Each sensor is hinged to the cutter head via a mechanical swing arm and tension spring assembly. Its core function is to convert the vertical displacement and tilt angle of the cutter head relative to the ground into standard electrical signals in real time without delay. Additionally, the system can integrate an inertial measurement unit (IMU) to detect the machine's attitude as an auxiliary compensation signal.

[0024] 2. Execution Module: Serving as the "hands and feet" of the system, the core is the hydraulic drive system. This system adopts a highly integrated design, and key components include: (1) Integrated electromagnetic proportional valve group: receives weak electrical signals from the controller and proportionally controls the flow and direction of hydraulic oil, thereby precisely driving the oil cylinder.

[0025] (2) Single-acting hydraulic cylinder for lifting the cutting table: responsible for the overall lifting of the cutting table.

[0026] (3) Double-acting hydraulic cylinder for swinging the cutting table: responsible for driving the cutting table to swing left and right around its pivot.

[0027] (4) Hydraulic check valve: Integrated into the key oil circuit, it acts like a "hydraulic lock" and can lock the oil cylinder at any position to prevent the cutting table from "sinking" due to its own weight or external impact, thus ensuring stable posture.

[0028] 3. Control Module: As the "brain" of the system, the core is a high-performance electronic control unit (ECU). It is responsible for receiving signals from all sensors, running the embedded intelligent control algorithm, and calculating precise commands to drive the proportional valve. Its hardware features multi-channel analog / digital input, high-speed CAN bus communication, and high-current drive output capabilities.

[0029] System installation and debugging process: First, fix the left and right angle sensors to the preset installation positions on the cutting table using the swing arm-tension spring assembly, ensuring that the sensor swing arm can swing flexibly with changes in terrain without jamming; then connect the hydraulic circuit, connecting the integrated electromagnetic proportional valve group with the oil cylinder and hydraulic control check valve according to the oil circuit design requirements, and conduct a sealing test; next, complete the electrical control wiring, connecting the sensors and solenoid valves to the corresponding interfaces of the ECU according to the wiring principle shown in Figure 7, ensuring that the power supply positive and negative terminals and signal lines are connected correctly; finally, perform system calibration, setting ideal working posture parameters (target height, levelness), calibrating the sensor zero point and range, and debugging the dual-loop control algorithm parameters to ensure that the system response time is <0.7 seconds and the control error is <7 mm.

[0030] During operation, as the harvester travels, angle sensors on both sides collect real-time signals of the ground clearance on both sides of the header. After fusion processing by the ECU, the pitch and roll angles of the header are calculated. The feedforward loop uses sensors on the flexible part of the header to predict changes in the terrain ahead, and the ECU outputs control commands to the electromagnetic proportional valve group in advance to drive the hydraulic cylinder to pre-act. The feedback loop monitors the actual posture of the header through sensors on the bridge section and feeds the signal back to the ECU for error correction, ensuring that the header posture accurately matches the terrain. The hydraulically controlled check valve continuously locks the position of the hydraulic cylinder during operation. When encountering hard soil or sudden changes in crop density that cause pressure fluctuations, the pressure sensor feedback signal triggers the ECU to perform adaptive pressure adjustment to prevent the header from jamming or "heading over".

[0031] The core principle of this system is "dual-loop adaptive control combining feedforward prediction and real-time feedback," and its workflow is a continuous closed loop: Step 1: Global Terrain Perception and Data Fusion During operation, the angle sensors on the left and right sides of the cutter head continuously measure the ground clearance of their respective positions via a swing arm-tension spring mechanism. The ECU performs high-speed sampling and fusion processing on these two signals, not simply taking the average value, but calculating the current real-time pitch and roll angles of the cutter head, thereby constructing a dynamic, high-fidelity three-dimensional contour of the terrain below the cutter head within the controller.

[0032] Step Two: Intelligent Decision-Making and Forward-Looking Predictions The ECU compares the calculated header posture with the preset ideal operating posture (target height, levelness). At the same time, the feedforward control loop starts working: the sensors located in the flexible part of the header contact the crop layer and terrain changes in front of it before the cutter. This signal is used to predict the upcoming terrain fluctuations and instruct the hydraulic system to start actuating in advance, thereby significantly offsetting the inherent mechanical and hydraulic delays of the system.

[0033] Step 3: Precise Execution and Closed-Loop Fine-Tuning The hydraulic system receives commands from the ECU. Proportional valves precisely regulate the flow rate into the lifting and swing cylinders, allowing the cutting table to move smoothly at a set speed (0.4 m / s up, 0.32 m / s down). A real-time feedback loop operates synchronously: sensors installed on the cutting table's bridge continuously monitor the actual posture of the cutting table after its final execution and feed this signal back to the ECU. This signal is compared with the target value, and any errors in the feedforward prediction are finely corrected, forming a precise closed-loop control.

[0034] Step 4: Dynamic Adaptation and Stability Maintenance Throughout the process, the hydraulic check valve ensures that the cylinder is firmly locked when there is no control command, maintaining a constant cutting platform height. When encountering locally hard or loose soil, the system pressure may fluctuate. The ECU can adaptively fine-tune the output based on pressure sensor feedback to prevent jamming or "head-down" and improve passability.

[0035] Functional description of each control component of the header This embodiment, through the above configuration and control logic, achieves precise contouring of the header in complex and uneven terrain, reduces crop loss rate by more than 40%, significantly decreases impurity content, and greatly improves operation quality and economic benefits, fully verifying the practicality and advancement of the technical solution of this invention.

[0036] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art will be able to make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. An independent cutter table adaptive contour control system based on multi-sensor fusion, characterized in that, It includes a sensing module, an execution module, and a control module, wherein the sensing module and the execution module are electrically connected to the control module. The sensing module includes high-precision angle sensors installed on the left and right sides of the cutting table. Each high-precision angle sensor is hinged to the cutting table via a mechanical rotating arm, a tension spring assembly, and a tension spring assembly, and is used to convert the vertical displacement and tilt angle of the cutting table relative to the ground into electrical signals. The sensing module may also selectively integrate an inertial measurement unit to detect the fuselage attitude and provide auxiliary compensation signals; The execution module is a hydraulic drive system, including an integrated electromagnetic proportional valve group, a single-acting cylinder for lifting the cutting table, a double-acting cylinder for swinging the cutting table, and a hydraulically controlled check valve. The integrated electromagnetic proportional valve group is connected to the single-acting cylinder for lifting the cutting table and the double-acting cylinder for swinging the cutting table through oil circuits, and the hydraulically controlled check valve is integrated into the oil circuits. The control module is a high-performance electronic control unit (ECU). The ECU has a built-in dual-loop intelligent control algorithm of "feedforward prediction + real-time feedback" to receive electrical signals from the sensing module, perform data fusion processing, and output control commands to the execution module. The ECU receives signals from the sensor on the flexible part of the cutter head through the feedforward loop to predict terrain changes, and receives signals from the sensor on the bridge part of the cutter head through the feedback loop to monitor attitude. After calculating and comparing the feedforward prediction and real-time feedback, the ECU dynamically corrects the control commands to achieve precise control of the cutter head attitude.

2. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The high-precision angle sensor has a signal output range of 0-5V and a detection angle range of 0-180°.

3. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The lifting speed of the single-acting hydraulic cylinder of the cutting platform is 0.4 m / s, and the lowering speed is 0.32 m / s.

4. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The synchronization error between the single-acting hydraulic cylinder for lifting the cutting table and the double-acting hydraulic cylinder for swinging the cutting table is ≤5%.

5. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The locking pressure range of the hydraulic control check valve is 20-170 bar, and it has an adaptive pressure adjustment function.

6. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The system response time of the dual-loop intelligent control algorithm is <0.7 seconds.

7. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The control error between the profile height of the cutting platform and the target height is <7 mm.

8. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The electronic control unit has multi-channel analog / digital input, high-speed CAN bus communication, and high-current drive output capabilities.

9. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The sensing module also includes a ground pressure sensor, which has a signal output range of 0-5V and a detection pressure range of 0-160BAR.

10. The independent cutter table adaptive contour control system based on multi-sensor fusion according to claim 1, characterized in that, The solenoid valve power supply specifications of the execution module include DC12V and DC24V. The solenoid valve built into the cutting table is powered by DC12V, while the bridge control solenoid valve is controlled by DC24V proportional current.

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