Grain unloading system of combine harvester and control method

Abstract

The invention belongs to the field of agricultural machinery, and particularly relates to a grain unloading system of a combine harvester and a control method. The system comprises a granary, wherein a granary allowance sensor is arranged on the granary; the first grain unloading barrel keeps communicating with the granary and can be driven by a first driving mechanism to rotate in the horizontal direction relative to the granary to adjust the horizontal rotating angle; the second grain unloading cylinder keeps communicating with the first grain unloading cylinder and can be driven by a second driving mechanism to rotate relative to the first grain unloading cylinder in the vertical direction to adjust the elevation angle; and the auger mechanism is arranged in the first grain unloading cylinder and the second grain unloading cylinder. Parameters such as the rotating angle of the grain unloading barrel, the grain flow and the granary allowance are collected in real time through the sensing detection mechanism, full-automatic closed-loop control over grain unloading barrel posture adjustment, auger rotating speed adjustment and system reset action is achieved in combination with the PLC and the multi-mode cooperative control module, a traditional manual operation mode is replaced, the labor intensity of a driver is remarkably reduced, and the working efficiency is improved. And the operation precision and the response speed are improved.

Description

Technical Field

[0001] The present invention belongs to the field of agricultural machinery, and particularly relates to a grain unloading system and control method for a combine harvester. Background Art

[0002] In modern large combine harvesters, the grain unloading is usually carried out by a grain unloading tube and an internal grain unloading auger to transport the grain from the grain bin to the transport vehicle hopper. The traditional adjustment of the position of the grain unloading tube mainly relies on manual operation. The driver needs to manually control the rotation angle and position of the grain unloading tube during unloading and judge the unloading speed according to experience. This manual method has many deficiencies: manual adjustment increases the labor intensity of the driver, and it is easy to have situations where the operation is not timely or in place during continuous operation; if the angle and orientation of the grain unloading tube are not accurately controlled, it may cause grain spillage or the grain cannot be accurately unloaded into the hopper.

[0003] The existing grain unloading augers of combine harvesters usually operate at a fixed speed and cannot be intelligently adjusted according to the grain flow rate. When the grain flow rate is too large, it is easy to cause blockage or overflow, and when the flow rate is too small, the unloading efficiency is reduced. The existing technology lacks an intelligent system that can automatically adjust the attitude of the grain unloading tube and control the unloading flow rate according to the actual unloading situation. Therefore, there is still room for improvement in terms of improving the unloading efficiency, reducing manual participation, and avoiding grain waste. Summary of the Invention

[0004] Aiming at the problems of difficult adjustment of the position of the grain unloading tube and the fixed rotation speed of the grain unloading auger that cannot be intelligently adjusted according to the grain flow rate in the existing technology, the present invention provides an intelligent control system for the grain unloading tube of a combine harvester, which can overcome certain or some defects of the existing technology.

[0005] According to a grain unloading system for a combine harvester of the present invention, it includes:

[0006] A grain bin, on which a grain bin remaining amount sensor is arranged;

[0007] A first grain unloading tube, which is in communication with the grain bin and can be driven by a first driving mechanism to rotate horizontally relative to the grain bin to adjust the horizontal rotation angle;

[0008] A second grain unloading tube, which is in communication with the first grain unloading tube and can be driven by a second driving mechanism to rotate vertically relative to the first grain unloading tube to adjust the elevation angle;

[0009] An auger mechanism, which is arranged in the first grain unloading tube and the second grain unloading tube. The auger mechanism is used to transport the grain entering the first grain unloading tube from the grain bin through the first grain unloading tube and the second grain unloading tube to the unloading port at the end of the second grain unloading tube and unload it into the transport vehicle hopper;

[0010] An optoelectronic sensor is disposed inside the second grain unloading cylinder to detect the grain flow rate inside the second grain unloading cylinder.

[0011] Preferably, a first driving mechanism is connected to the bottom end of the first grain unloading cylinder. The first driving mechanism includes:

[0012] A mounting seat is connected to the granary;

[0013] A driving motor is mounted on the mounting seat;

[0014] A driving gear is connected to the output shaft of the driving motor;

[0015] A driven gear meshes with the driving gear and is connected to the first grain unloading cylinder through a fastener to drive the first grain unloading cylinder to rotate relative to the granary in the horizontal direction to adjust the horizontal rotation angle.

[0016] Preferably, a second driving mechanism is connected to the top end of the first grain unloading cylinder. The second driving mechanism includes:

[0017] A connecting cylinder, the first end of which is hinged to the top end of the first grain unloading cylinder, and the second end of which is fixedly connected to the end of the second grain unloading cylinder far from the grain unloading port;

[0018] A hydraulic cylinder is mounted on the first grain unloading cylinder. The telescopic end of the hydraulic cylinder is connected to the second grain unloading cylinder to drive the first grain unloading cylinder to rotate in the vertical direction to adjust the elevation angle through the telescopic movement of the hydraulic cylinder.

[0019] Preferably, an angle sensor is provided at the hinged position of the connecting cylinder and the first grain unloading cylinder. The angle sensor is used to detect the included angle between the second grain unloading cylinder and the connecting cylinder relative to the first grain unloading cylinder to determine the elevation angle.

[0020] Preferably, it further includes:

[0021] An industrial camera is disposed at the grain unloading port. The industrial camera is used to acquire real-time images inside the transport vehicle hopper.

[0022] The present invention also provides a control method for a grain unloading system of a combine harvester, which is carried out based on the described grain unloading system of a combine harvester. The control method includes:

[0023] In response to the granary margin sensor detecting that the granary margin in the granary reaches a preset threshold, triggering a grain unloading instruction;

[0024] In response to the grain unloading instruction, determining an action strategy according to the preset position coordinate parameters of the transport vehicle hopper;

[0025] Rotating the first grain unloading cylinder and the second grain unloading cylinder to the in-place position according to the action strategy, aligning the grain unloading port with the center of the transport vehicle hopper and starting the auger mechanism to unload grain at an initial speed;

[0026] During the grain unloading process, based on the remaining amount of grain in the granary detected by the remaining amount sensor of the granary, the environmental parameters detected by the pre-arranged environmental sensors, and the position coordinate parameters of the transport vehicle hopper, it is determined whether to enter a specific control mode;

[0027] If it is necessary to enter a specific control mode, control the auger mechanism, the first drive mechanism, and the second drive mechanism according to the specific control mode;

[0028] If it is not necessary to enter a specific control mode, perform hierarchical control on the auger mechanism according to the grain flow detected by the photoelectric sensor.

[0029] Preferably, a first threshold and a second threshold that increase sequentially are preset for the remaining amount of grain in the granary; the environmental parameters include wind speed and terrain inclination angle;

[0030] The step of determining whether to enter a specific control mode includes:

[0031] If the remaining amount of grain in the granary is greater than the second threshold and the position coordinate parameters of the transport vehicle hopper are fixed, enter the high-load mode;

[0032] If the remaining amount of grain in the granary is less than the first threshold and both the wind speed and the terrain inclination angle are less than the corresponding thresholds, enter the energy-saving mode;

[0033] If both the wind speed and the terrain inclination angle are greater than the corresponding thresholds, enter the anti-interference mode;

[0034] The priority order is the anti-interference mode, the high-load mode, and the energy-saving mode.

[0035] Preferably, a first duty cycle, a second duty cycle, and a third duty cycle that increase sequentially are preset for the motor PWM duty cycle of the auger mechanism;

[0036] The rotation speed of the auger mechanism is preset with a first rotation speed, a second rotation speed, a third rotation speed, a fourth rotation speed, a fifth rotation speed, and a sixth rotation speed that increase sequentially; the third rotation speed is used as the initial rotation speed;

[0037] The grain flow is preset with a first flow rate and a second flow rate that increase sequentially;

[0038] When it is determined that it is necessary to enter a specific control mode:

[0039] The control strategy of the high-load mode includes adjusting the PWM duty cycle of the auger mechanism to the third duty cycle and the rotation speed of the auger mechanism to the sixth rotation speed; controlling the second drive mechanism to raise the elevation angle of the second discharge chute to the corresponding preset value; controlling the first drive mechanism to keep the discharge port aligned with the center of the transport vehicle hopper;

[0040] The control strategy of the energy-saving mode includes controlling the rotation speed of the auger mechanism within the range between the second rotation speed and the fourth rotation speed, and keeping the second driving mechanism in the low-power mode;

[0041] The control strategy of the anti-interference mode includes enabling overload protection for the motor of the auger mechanism, increasing the output torque of the motor by a preset ratio from the default value, controlling the second driving mechanism to lower the elevation angle of the second discharge chute to the corresponding preset value; calibrating the horizontal rotation angle of the first discharge chute every preset time interval to compensate for the offset caused by wind or slope;

[0042] When it is determined that there is no need to enter a specific control mode:

[0043] If the grain flow rate is greater than the second flow rate, adjust the PWM duty cycle of the motor of the auger mechanism to the first duty cycle and adjust the rotation speed to the first rotation speed;

[0044] If the grain flow rate is greater than the first flow rate and less than the second flow rate, the auger mechanism maintains the current rotation speed unchanged;

[0045] If the grain flow rate is less than the first flow rate, modulate the PWM duty cycle of the motor of the auger mechanism to the second duty cycle and adjust the rotation speed to the fifth rotation speed.

[0046] Preferably, the control method further includes:

[0047] If the grain flow rate is lower than the preset flow rate lower limit value and lasts for more than the corresponding preset time, reduce the rotation speed of the auger mechanism by a preset ratio every preset time period until the rotation speed is reduced to the preset rotation speed lower limit value, and at the same time, lower the elevation angle of the second grain discharge chute by a preset angle every preset time period until it returns to the zero position;

[0048] Preferably, the control method further includes:

[0049] If the remaining amount of the grain bin detected by the grain bin remaining amount sensor is less than the preset remaining amount lower limit value, and the grain flow rate is zero and lasts for more than the corresponding preset time, send a stop signal to the auger mechanism;

[0050] In response to the stop signal, the auger mechanism stops operating and controls the first driving mechanism and the second driving mechanism to reset;

[0051] The control of the first driving mechanism and the second driving mechanism to reset includes:

[0052] Controlling the second driving mechanism to lower the elevation angle of the second grain discharge chute at the corresponding preset angular velocity until the initial zero position;

[0053] Controlling the first driving mechanism to return the horizontal rotation angle of the first grain discharge chute to the initial zero position at the corresponding preset angular velocity;

[0054] The control method further includes:

[0055] If the horizontal rotation angle of the first grain unloading cylinder or the elevation angle of the second grain unloading cylinder deviates from the target angle by more than the corresponding preset threshold for a preset time, an action stop instruction is triggered to keep the current state and stop.

[0056] The control method further includes:

[0057] If the grain coverage area in the real-time image of the transport vehicle hopper collected by the industrial camera at the grain unloading port is empty, and the grain flow rate detected by the photoelectric sensor is above the corresponding preset threshold, an alarm instruction is triggered to prompt manual review of the industrial camera or cleaning of the lens.

[0058] The control method further includes:

[0059] An abnormal area with insufficient grain coverage in the transport vehicle hopper is obtained by processing the real-time image of the transport vehicle hopper collected by the industrial camera.

[0060] According to the central coordinates of the abnormal area, the rotation angles of the first grain unloading cylinder and the second grain unloading cylinder are adjusted so that the grain unloading port is aligned with the abnormal area for grain unloading.

[0061] Compared with the prior art, the present invention has the following remarkable improvements:

[0062] (1) The present invention can collect the remaining amount of the grain bin in real time, and based on the remaining amount of the grain bin, the pre-acquired environmental parameters and the position coordinate parameters of the transport vehicle hopper, comprehensively consider whether to determine whether to enter a specific working mode, and automatically control the first grain unloading cylinder, the second grain unloading cylinder and the auger mechanism according to the specific control strategy in the specific working mode to adapt to various actual working conditions, so as to ensure that the grain unloading operation can be kept safe and stable in various working conditions as much as possible. If it is not necessary to enter a specific working mode, the grain unloading mechanism is controlled in stages according to the grain flow rate, so as to improve the grain unloading efficiency as much as possible while ensuring safety. The present invention can replace the traditional manual operation mode through full-automatic closed-loop control, significantly reduce the labor intensity of the driver, and improve the operation accuracy and response speed.

[0063] (2) The present invention introduces an image recognition module, which uses an industrial camera to collect the internal image of the transport vehicle hopper, can automatically identify the area in the hopper that has not been fully unloaded with grain, and feedback the coordinates of the abnormal area as the target area to the PLC controller. By comparing with the current posture of the grain unloading cylinder, the system automatically generates the required adjustment amount of the horizontal rotation angle of the first grain unloading cylinder and the elevation angle adjustment amount of the second grain unloading cylinder, so as to realize the accurate deviation correction of the grain unloading direction and further improve the accuracy and operation efficiency of grain unloading.

[0064] (3) When the remaining amount in the grain bin drops to the threshold or the flow rate remains too low, the system automatically starts the progressive deceleration program, gradually reducing the auger rotation speed and decreasing the elevation angle of the second grain unloading cylinder to avoid the accumulation of residual grains. During the reset process, the angle sensor monitors the position deviation throughout. If the reset is abnormal, an alarm is triggered and the system is locked to ensure safe and reliable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a schematic structural diagram of the grain unloading system of the combine harvester in the present invention;

[0066] Figure 2 is Figure 1 a schematic structural diagram from another perspective;

[0067] Figure 3 is a schematic structural diagram of the first driving mechanism of the present invention;

[0068] Figure 4 is a schematic position diagram of the photoelectric sensor of the present invention;

[0069] Figure 5 is a schematic position diagram of the industrial camera of the present invention

[0070] Figure 6 is a flowchart of the grain unloading operation of the present invention;

[0071] Figure 7 is a flowchart of the grain flow rate monitoring of the present invention.

[0072] Reference numerals in the figures: 1, industrial camera; 101, camera body; 102, camera mounting seat; 2, grain unloading port; 3, second grain unloading cylinder; 4, hydraulic cylinder; 5, angle sensor; 6, connecting cylinder; 7, first grain unloading cylinder; 8, first driving mechanism; 801, driving motor; 802, driving gear; 803, driven gear; 804, fastener; 9, remaining amount sensor in the grain bin; 10, auger mechanism; 11, auger rotating shaft; 12, photoelectric sensor; 1201, sensor seat; 1202, sensing element. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0073] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0074] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0075] Embodiment 1

[0076] In order to make the purpose, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the drawings and embodiments.

[0077] Combined with Figures 1-5 , this embodiment provides a grain unloading system for a combine harvester, which includes a grain bin, a first grain unloading cylinder 7, a second grain unloading cylinder 3, a screw conveyor mechanism 10, and a photoelectric sensor 12.

[0078] A grain bin surplus sensor 9 is arranged on the grain bin; in a specific embodiment, the grain bin surplus sensor 9 can determine the surplus of the grain bin through visual images or through the weight of the grain, and can also adopt existing sensors with the same function in the prior art, and this embodiment does not make specific limitations.

[0079] The first grain unloading tube 7 is in communication with the grain bin and can be driven by a first driving mechanism 8 to rotate relative to the grain bin in the horizontal direction to adjust the horizontal rotation angle. The second grain unloading tube 3 is in communication with the first grain unloading tube 7 and can be driven by a second driving mechanism to rotate relative to the first grain unloading tube 7 in the vertical direction to adjust the elevation angle. It can be understood that in actual use, in order to adapt to the real-time position of the transport vehicle, the grain unloading direction needs to be adjusted in real time. The first driving mechanism 8 and the second driving mechanism in this embodiment can respectively drive the first grain unloading tube 7 and the second grain unloading tube 3 to adjust the horizontal rotation angle and the elevation angle to adapt to different working conditions.

[0080] In some specific embodiments, the first driving mechanism 8 includes a mounting seat, a driving motor 801, a driving gear 802 and a driven gear 803; the mounting seat is connected to the grain bin; the driving motor 801 is mounted on the mounting seat; the driving gear 802 is connected to the output shaft of the driving motor 801; the driven gear 803 meshes with the driving gear 802 and connects the first grain unloading tube 7 through a fastener 804 to drive the first grain unloading tube 7 to rotate relative to the grain bin in the horizontal direction to adjust the horizontal rotation angle. The top end of the first grain unloading tube 7 is connected with a second driving mechanism, and the second driving mechanism includes a connecting tube 6 and a hydraulic cylinder 4; the first end of the connecting tube 6 is hinged to the top end of the first grain unloading tube 7, and the second end is fixedly connected to one end of the second grain unloading tube 3 away from the grain unloading port 2; the hydraulic cylinder 4 is mounted on the first grain unloading tube 7, and the telescopic end of the hydraulic cylinder 4 is connected to the second grain unloading tube 3 to drive the first grain unloading tube 7 to rotate in the vertical direction to adjust the elevation angle through the telescopic movement of the hydraulic cylinder 4. An angle sensor 5 is provided at the hinged position of the connecting tube 6 and the first grain unloading tube 7, and the angle sensor 5 is used to detect the included angle between the second grain unloading tube 3 and the connecting tube 6 relative to the first grain unloading tube 7 to determine the elevation angle, so as to monitor the elevation angle in real time for easy control.

[0081] The auger mechanism 10 is arranged in the first grain unloading tube 7 and the second grain unloading tube 3, and the auger shaft 11 of the auger mechanism 10 is arranged along the extending direction of the first grain unloading tube 7 and the second grain unloading tube 3; the auger mechanism 10 is used to transport the grains entering the first grain unloading tube 7 from the grain bin through the first grain unloading tube 7 and the second grain unloading tube 3 to the grain unloading port 2 at the end of the second grain unloading tube 3 and unload them into the transport vehicle hopper. The PWM duty cycle and the rotation speed of the auger mechanism 10 can be controlled in real time to meet the safety requirements or high-efficiency requirements of different working conditions. The photoelectric sensor 12 is arranged in the second grain unloading tube 3 to detect the grain flow rate in the second grain unloading tube 3. The photoelectric sensor 12 includes a sensor base 1201 and a sensing element 1202 mounted on the sensor base 1201.

[0082] In a specific embodiment, an industrial camera 1 is further provided at the grain unloading port 2. The industrial camera 1 is disposed at the grain unloading port 2 and includes a camera mounting base 102 mounted on the second grain unloading cylinder 3 and a camera body 101 mounted on the camera mounting base 102. The industrial camera 1 is used to obtain real-time images inside the transport vehicle hopper to determine the grain coverage inside the transport vehicle hopper, so as to adaptively adjust the grain unloading direction and grain unloading strategy.

[0083] Embodiment 2

[0084] Combined with Figure 6 and Figure 7 , this embodiment provides a control method for a grain unloading system of a combine harvester in Embodiment 1. The control method includes:

[0085] Step S1: In response to the grain bin surplus sensor 9 detecting that the grain bin surplus in the grain bin reaches a preset threshold, trigger a grain unloading instruction;

[0086] Step S2: In response to the grain unloading instruction, determine an action strategy according to the preset position coordinate parameters of the transport vehicle hopper. In this embodiment, before responding to the grain unloading instruction, it is also necessary to perform an initialization self-check operation on the grain bin surplus sensor 9, the photoelectric sensor 12, the angle sensor 5, the first grain unloading cylinder 7, and the second grain unloading cylinder 3. The angle sensor 5 calibrates the zero point to confirm that the second grain unloading cylinder 3 is in the initial receiving position, parallel to the longitudinal axis of the combine harvester, with an elevation angle of 0°. The photoelectric sensor 12 starts the light source detection to confirm that the light path is unobstructed. The grain bin surplus sensor 9 scans the bottom of the grain bin to generate an initial surplus reference value. After the system initialization self-check operation is passed, the PLC controller (PLC control is adopted in this embodiment, and other control methods with the same function in the prior art can also be used) sends a start signal to the second driving mechanism (the hydraulic cylinder 4 in this embodiment), and the auger mechanism 10 enters the standby state.

[0087] Step S3: Rotate the first grain unloading cylinder 7 and the second grain unloading cylinder 3 to the in-place position according to the action strategy, align the grain unloading port 2 with the center of the transport vehicle hopper, and start the auger mechanism 10 to unload grain at the initial speed;

[0088] As a specific example, the rotation modes of the first grain unloading cylinder 7 and the second grain unloading cylinder 3 in this embodiment are:

[0089] Horizontal rotation: The first driving mechanism 8 drives the first grain unloading cylinder 7 to rotate horizontally around the bottom hinge point, and the angle sensor 5 feeds back the horizontal rotation angle data to the PLC controller in real time.

[0090] Elevation angle adjustment: The second driving mechanism pushes the second grain unloading cylinder 3 to swing upward to a preset elevation angle of 15° to ensure that the grain unloading port 2 is aligned with the center of the transport vehicle hopper.

[0091] In this embodiment, the PLC controller controls the opening of the hydraulic proportional valve of the hydraulic cylinder 4 in the second driving mechanism through the PID algorithm in a closed-loop manner. By controlling the control current of the hydraulic proportional valve, the opening of the hydraulic proportional valve of the hydraulic cylinder 4 can be controlled, thereby dynamically adjusting the hydraulic flow rate so that the error between the actual rotation angle and the target angle of the grain unloading cylinder is ≤ ±1°.

[0092] Further, the grain unloading mechanism starts and runs at an initial speed (500 rpm in this embodiment). The photoelectric sensor 12 continuously detects the grain flow rate in the second grain unloading cylinder 3, calculates the instantaneous flow rate value through the light intensity attenuation rate, and sends the grain flow rate data to the PLC controller.

[0093] Step S4: During the grain unloading process, determine whether to enter a specific control mode according to the remaining amount of the grain bin detected by the grain bin remaining amount sensor 9, the environmental parameters detected by the pre-arranged environmental sensors, and the position coordinate parameters of the transport vehicle hopper.

[0094] The purpose of setting the specific control mode in this embodiment is that during the grain unloading process, both the remaining amount of the grain bin and the working environment will change in real time, so there may be various situations that can affect the safety of grain unloading, or there may be situations that are relatively safe and energy-saving. Therefore, it is necessary to adjust the control strategy to adapt to these possible situations to ensure the continuous, safe and stable operation of the grain unloading operation.

[0095] In some specific embodiments, the remaining amount of the grain bin is preset with a first threshold and a second threshold that increase in sequence; the environmental parameters include wind speed and terrain inclination angle; the specific control modes include high-load mode, energy-saving mode, and anti-interference mode.

[0096] If the remaining amount of the grain bin is greater than the second threshold and the position coordinate parameters of the transport vehicle hopper are fixed, enter the high-load mode;

[0097] If the remaining amount of the grain bin is less than the first threshold and both the wind speed and the terrain inclination angle are less than the corresponding thresholds, enter the energy-saving mode;

[0098] If both the wind speed and the terrain inclination angle are greater than the corresponding thresholds, enter the anti-interference mode;

[0099] The priority order is anti-interference mode, high-load mode, and energy-saving mode.

[0100] As a specific example, it is described in combination with optional typical values:

[0101] If the remaining amount of the grain bin > 70% and the position of the transport vehicle hopper is fixed (horizontal coordinate fluctuation ≤ ±0.5 m), then enter the high-load mode;

[0102] If the remaining amount of the grain bin < 30% and the wind speed ≤ 5 m / s, terrain inclination angle ≤ 5°, then switch to the energy-saving mode;

[0103] If the wind speed > 5 m / s or the terrain inclination angle > 5°, the anti-interference mode is forced to be enabled.

[0104] This is an optional example. The specific threshold can be adaptively adjusted according to actual requirements or obtained through pre-calibration. This embodiment does not make specific limitations.

[0105] Step S5: If it is necessary to enter a specific control mode, control the auger mechanism 10, the first drive mechanism 8, and the second drive mechanism according to the specific control mode; if it is not necessary to enter a specific control mode, perform hierarchical control on the auger mechanism 10 according to the grain flow detected by the photoelectric sensor 12.

[0106] In some specific embodiments, the specific control strategies for each specific control mode and the normal mode when it is not necessary to enter a specific control mode are described as follows:

[0107] First, in this embodiment, the PWM duty cycle of the motor of the auger mechanism 10 is preset with a first duty cycle, a second duty cycle, and a third duty cycle that increase in sequence (the optional typical values can be 40%, 70%, 85%); the rotation speed of the auger mechanism 10 is preset with a first rotation speed, a second rotation speed, a third rotation speed, a fourth rotation speed, a fifth rotation speed, and a sixth rotation speed that increase in sequence (the optional typical values can be 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm); the third rotation speed is used as the initial rotation speed; the grain flow is preset with a first flow rate and a second flow rate that increase in sequence (the optional typical values can be 30 kg / s and 80 kg / s);

[0108] When it is determined that it is necessary to enter a specific control mode:

[0109] The control strategy of the high-load mode includes adjusting the PWM duty cycle of the auger mechanism 10 to the third duty cycle and the rotation speed of the auger mechanism 10 to the sixth rotation speed; controlling the second drive mechanism to raise the elevation angle of the second discharge chute to the corresponding preset value; controlling the first drive mechanism 8 to keep the discharge port aligned with the center of the transport vehicle hopper; as a specific example, it is described in combination with the optional typical values: the PWM duty cycle of the auger motor is increased to 85%, and the rotation speed is increased to 800 rpm; the hydraulic cylinder 4 increases the elevation angle of the second grain discharge chute 3 to 30°, and fine-tunes the horizontal rotation angle of the first grain discharge chute 7 through the first drive mechanism 8 to ensure that the discharge port 2 is aligned with the center of the hopper.

[0110] The control strategy of the energy-saving mode includes controlling the rotation speed of the auger mechanism 10 within the range between the second rotation speed and the fourth rotation speed, and keeping the second driving mechanism in the low-power mode; as a specific example, it is described in combination with optional typical values: the auger rotation speed is dynamically adjusted to 400-600 rpm; the hydraulic cylinder 4 is switched to the low-power mode, and the opening of the hydraulic proportional valve is limited to 50%.

[0111] The control strategy of the anti-interference mode includes enabling overload protection for the motor of the auger mechanism 10, increasing the output torque of the motor by a preset proportion, controlling the second driving mechanism to lower the elevation angle of the second discharge chute to the corresponding preset value; calibrating the horizontal rotation angle of the first discharge chute at preset intervals to compensate for the offset caused by wind or slope; as a specific example, it is described in combination with typical values: overload protection is enabled for the motor of the auger mechanism 10, and the output torque is increased by 20%; the elevation angle of the second grain discharge chute 3 is reduced to 10°, and the horizontal rotation angle of the first grain discharge chute 7 is dynamically calibrated every 5 seconds to compensate for the offset caused by wind or slope.

[0112] The mode switching priority is: anti-interference mode > high-load mode > energy-saving mode, ensuring the priority of operation safety. The flow data is updated every 0.1 second, and the PLC controller dynamically adjusts the rotation speed of the auger mechanism 10 to ensure that the fluctuation range of the grain flow ≤ ±5%.

[0113] Further, when it is determined that there is no need to enter a specific control mode:

[0114] If the grain flow is greater than the second flow, adjust the PWM duty cycle of the motor of the auger mechanism 10 to the first duty cycle, and adjust the rotation speed to the first rotation speed;

[0115] If the grain flow is greater than the first flow and less than the second flow, the auger mechanism 10 maintains the current rotation speed unchanged;

[0116] If the grain flow is less than the first flow, modulate the PWM duty cycle of the motor of the auger mechanism 10 to the second duty cycle, and adjust the rotation speed to the fifth rotation speed.

[0117] As a specific example, it is described in combination with optional typical values:

[0118] The PLC controller executes a hierarchical control strategy according to the grain flow value, including:

[0119] High flow range (≥80 kg / s): Reduce the PWM duty cycle of the auger motor to 40%, and the rotation speed drops to 300 rpm to prevent blockage.

[0120] Medium flow range (30-80 kg / s): Maintain the current rotation speed.

[0121] Low flow range (<30 kg / s): Increase the duty cycle to 70% and the rotational speed to 700 rpm to improve the grain unloading efficiency.

[0122] In this embodiment, the hierarchical control strategy can keep the grain flow within a safe range, thereby preventing blockage while ensuring efficient grain unloading. During the grain unloading process, the grain bin remaining amount sensor 9 continuously monitors the grain stock in the grain bin. When the remaining amount in the grain bin drops to the threshold value (i.e., 5%), the PLC controller enters the end-of-grain-unloading mode.

[0123] In a specific embodiment, the control method in this embodiment further includes: If the grain flow is continuously lower than the preset lower flow limit value for a corresponding preset time, the rotational speed of the auger mechanism 10 is reduced by a preset proportion every preset period until the rotational speed is reduced to the preset lower rotational speed limit value. At the same time, the elevation angle of the second grain unloading tube 3 is adjusted downward by a preset angle every preset period until it returns to the zero position.

[0124] As a specific example, it is described in combination with optional typical values:

[0125] When the photoelectric sensor 12 detects that the grain flow is continuously lower than 10 kg / s for more than 10 seconds, the PLC controller starts the progressive deceleration program, reducing the rotational speed of the auger mechanism 10 by 10% every 5 seconds until the rotational speed drops to 100 rpm. At the same time, the hydraulic cylinder 4 gradually reduces the elevation angle of the grain unloading tube 3 (adjusting 2° each time) to prevent the remaining grain from accumulating due to insufficient gravity.

[0126] In a specific embodiment, the control method in this embodiment further includes:

[0127] If the remaining amount of the grain bin detected by the grain bin remaining amount sensor 9 is less than the preset lower remaining amount limit value, and the grain flow is zero and continues to exceed the corresponding preset time, a shutdown signal is sent to the auger mechanism 10;

[0128] In response to the shutdown signal, the auger mechanism 10 stops operating and controls the first drive mechanism 8 and the second drive mechanism to reset;

[0129] The control to reset the first drive mechanism 8 and the second drive mechanism includes:

[0130] Controlling the second drive mechanism to make the elevation angle of the second grain unloading tube 3 drop to the initial zero position at the corresponding preset angular velocity;

[0131] Controlling the first drive mechanism 8 to make the horizontal rotation angle of the first grain unloading tube 7 return to the initial zero position at the corresponding preset angular velocity;

[0132] As a specific example, it is described in combination with optional typical values:

[0133] When the remaining amount sensor 9 of the grain bin detects that the remaining amount ≤ 1% and the flow rate is 0 kg / s for 5 seconds, the PLC controller executes a reset instruction: sending a stop signal to the grain unloading auger mechanism 10, and the auger mechanism 10 completely stops running. Start the hydraulic cylinder 4 and drive the second grain unloading cylinder 3 to reset in two steps in the low-speed mode.

[0134] Specifically, the reset action of the second grain unloading cylinder 3 includes;

[0135] Elevation angle reset: The hydraulic cylinder 4 slowly contracts, and the elevation angle of the second grain unloading cylinder 3 drops to 0° at a rate of 0.5° / s.

[0136] Horizontal reset: The first driving mechanism 8 rotates in the reverse direction, and the horizontal rotation angle of the first grain unloading cylinder 7 returns to the initial receiving position at a rate of 5° / s.

[0137] The angle sensor 5 monitors the reset process throughout. If the target position is not reached within 10 seconds, the PLC triggers an abnormal alarm (sound and light prompt) and locks the system waiting for manual intervention. After the reset is completed, the PLC controller turns off the power supply of the hydraulic system and enters the low-power standby state.

[0138] Embodiment 3

[0139] Based on the control method given in Embodiment 2, this embodiment also provides a control method introducing an image recognition module, which is specifically described as follows:

[0140] Specifically, in this embodiment, the industrial camera 1 is fixedly installed on the end face of the second grain unloading cylinder 3, 50 - 60 cm above the grain unloading port 2, and is installed looking down towards the inside of the transport vehicle hopper, and the field of view can completely cover the main area inside the hopper.

[0141] After the grain unloading instruction is started, the industrial camera 1 adjusts the focal length and angle to ensure that the loading area of the hopper is located at the center of the screen. The image processing unit loads preset parameters (including hopper size, height threshold, etc.) and starts real-time video stream analysis.

[0142] It can be understood that the industrial camera 1 is connected to the image processing unit, which has a lightweight target recognition model built-in, and can use an image segmentation algorithm based on deep learning to process the real-time image and extract the grain coverage in the transport vehicle hopper.

[0143] Furthermore, the image processing unit updates the image recognition result every second, determines the area with insufficient grain coverage in the transport vehicle hopper as the abnormal area, and sends the center coordinates of the abnormal area to the PLC controller. The PLC controller accordingly adjusts the horizontal rotation angle of the first grain unloading cylinder 7 through the first driving mechanism 8, and then adjusts the elevation angle of the second grain unloading cylinder 3 through the hydraulic cylinder 4 to align the grain unloading port 2 with the area where the grain pile coverage in the transport vehicle hopper is insufficient, and controls the grain unloading direction.

[0144] Understandably, the PLC controller in this embodiment compares the coordinates of the vacant area (or abnormal area) fed back by the image recognition module with the position of the unloading port 2 of the current grain unloading cylinder, and calculates the difference Δθ in the horizontal rotation angle and the adjustment amount Δφ in the elevation angle that need to be adjusted. The PLC controller converts the image coordinates into the target offset angle through a built-in two-dimensional coordinate conversion model (the corresponding relationship between the relative coordinate system of the transport hopper and the coordinate system of the grain unloading cylinder has been calibrated), and generates a real-time control instruction:

[0145] If Δθ≠0, control the first driving mechanism 8 to rotate forward or backward, driving the first grain unloading cylinder 7 to rotate around the vertical axis until the horizontal angle deviation is less than the set threshold (i.e., ±1°); at the same time, if Δφ≠0, adjust the cylinder telescopic length of the hydraulic cylinder 4 to drive the elevation angle change of the second grain unloading cylinder 3 to ensure that the unloading port 2 is aligned with the target area in the vertical direction.

[0146] Understandably, during the entire adjustment process, the angle sensor 5 can real-time feedback the current angle data of the second grain unloading cylinder 3, sampling once every 0.1 seconds, and the PLC controller continuously corrects the control signal according to the error value to form a closed-loop control logic.

[0147] Specifically illustrated with a specific example. For example, when the image recognition module detects that there is an uncovered area in the front right area of the hopper (with the origin at the center of the hopper and the offset coordinates being X = +0.8m, Y = +0.5m), the PLC converts this offset into the first grain unloading cylinder 7 needing to rotate clockwise by about 15°, and the second grain unloading cylinder 3 raises the elevation angle by about 5°. Subsequently, corresponding control signals are sent to the drive motor 801 of the first driving mechanism 8 and the hydraulic cylinder 4 of the second driving mechanism to achieve automatic correction of the grain unloading direction and precise alignment with the target area.

[0148] Understandably, in this embodiment, to ensure the continuity of grain unloading, the control instruction keeps the operating state of the auger mechanism 10 while adjusting the angle to avoid interruption of grain unloading.

[0149] Furthermore, the present invention provides a system protection mechanism. If the horizontal rotation angle of the first grain unloading cylinder 7 or the elevation angle of the second grain unloading cylinder 3 deviates from the corresponding preset threshold relative to the target angle for more than the preset time, a stop instruction for the action is triggered to maintain the current state and stop, thereby ensuring the structural safety.

[0150] As a specific example, in combination with optional typical values for description, if the first grain unloading cylinder 7 and the second grain unloading cylinder 3 deviate from the target angle by less than the set threshold within 3 consecutive seconds of recognition, the control action stops and the system maintains the current state to prevent unnecessary angle jitter.

[0151] Furthermore, this embodiment also provides a fault handling mechanism, which makes a combined judgment based on the image recognition result and the grain flow information detected by the optoelectronic sensor 12. If the grain coverage area in the transport hopper is empty as feedback by the industrial camera 1 but the optoelectronic sensor 12 still detects a high grain flow, the system issues a prompt alarm to require manual review of the industrial camera 1 or cleaning of the lens.

[0152] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application based on one or several embodiments provided by the present application to obtain other embodiments, and none of these embodiments exceeds the protection scope of the present application.

[0153] The present invention and its implementation manners are schematically described above. This description is not restrictive. What is shown in the embodiments is only part of the implementation manners of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and design a structural manner and an embodiment similar to the technical solution without creative work without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A grain unloading system for a combine harvester, characterized in that, Including: A grain bin, on which a grain bin remaining amount sensor is arranged; A first grain unloading tube, which is in communication with the grain bin and can be driven by a first driving mechanism to rotate relative to the grain bin in the horizontal direction to adjust the horizontal rotation angle; A second grain unloading tube, which is in communication with the first grain unloading tube and can be driven by a second driving mechanism to rotate relative to the first grain unloading tube in the vertical direction to adjust the elevation angle; A screw conveyor mechanism, which is arranged in the first grain unloading tube and the second grain unloading tube. The screw conveyor mechanism is used to convey the grains entering the first grain unloading tube from the grain bin through the first grain unloading tube and the second grain unloading tube to the unloading port at the end of the second grain unloading tube and unload them into the transport vehicle hopper; An optoelectronic sensor, which is arranged in the second grain unloading tube to detect the grain flow rate in the second grain unloading tube.

2. The grain unloading system of the combine harvester according to claim 1, characterized in that, The bottom end of the first grain unloading tube is connected with a first driving mechanism, and the first driving mechanism includes: A mounting seat, which is connected to the grain bin; A driving motor, which is mounted on the mounting seat; A driving gear, which is connected to the output shaft of the driving motor; A driven gear, which meshes with the driving gear and is connected to the first grain unloading tube through a fastener to drive the first grain unloading tube to rotate relative to the grain bin in the horizontal direction to adjust the horizontal rotation angle.

3. The grain unloading system of the combine harvester according to claim 1, characterized in that, The top end of the first grain unloading tube is connected with a second driving mechanism, and the second driving mechanism includes: A connecting tube, the first end of which is hinged to the top end of the first grain unloading tube, and the second end of which is fixedly connected to the end of the second grain unloading tube far from the unloading port; A hydraulic cylinder, which is mounted on the first grain unloading tube, and the telescopic end of the hydraulic cylinder is connected to the second grain unloading tube to drive the first grain unloading tube to rotate in the vertical direction to adjust the elevation angle through the telescopic movement of the hydraulic cylinder.

4. The grain unloading system of the combine harvester according to claim 3, wherein, An angle sensor is arranged at the hinged position of the connecting tube and the first grain unloading tube. The angle sensor is used to detect the included angle between the second grain unloading tube and the connecting tube relative to the first grain unloading tube to determine the elevation angle.

5. The grain unloading system of the combine harvester according to claim 1, wherein Also including: An industrial camera, which is arranged at the unloading port. The industrial camera is used to obtain a real-time image in the transport vehicle hopper.

6. A control method for a grain unloading system of a combine harvester, characterized in that, Based on any one of claims 1-5, a control method for a combine harvester grain unloading system is carried out, and the control method includes: In response to the grain bin remaining amount sensor detecting that the remaining amount in the grain bin reaches a preset threshold, triggering a grain unloading instruction; In response to the grain unloading instruction, determining an action strategy according to the preset position coordinate parameters of the transport vehicle hopper; Rotating the first grain unloading tube and the second grain unloading tube to the in-place position according to the action strategy, aligning the unloading port with the center of the transport vehicle hopper and starting the screw conveyor mechanism to unload grains at an initial speed; During the grain unloading process, according to the remaining amount of the grain bin detected by the grain bin remaining amount sensor, the environmental parameters detected by the pre-arranged environmental sensors and the position coordinate parameters of the transport vehicle hopper, determining whether to enter a specific control mode; If it is necessary to enter a specific control mode, controlling the screw conveyor mechanism, the first driving mechanism and the second driving mechanism according to the specific control mode; If it is not necessary to enter a specific control mode, performing hierarchical control on the screw conveyor mechanism according to the grain flow rate detected by the optoelectronic sensor.

7. The control method of a grain unloading system of a combine harvester according to claim 6, characterized in that, The remaining amount of the grain bin is preset with a first threshold and a second threshold that increase in sequence; the environmental parameters include wind speed and terrain inclination angle; The step of determining whether to enter a specific control mode includes: If the remaining amount in the granary is greater than the second threshold and the position coordinate parameters of the transport hopper are fixed, enter the high-load mode; If the remaining amount in the granary is less than the first threshold and both the wind speed and the terrain inclination angle are less than the corresponding thresholds, enter the energy-saving mode; If both the wind speed and the terrain inclination angle are greater than the corresponding thresholds, enter the anti-interference mode; The priority order is the anti-interference mode, the high-load mode, and the energy-saving mode.

8. The control method of a grain unloading system of a combine harvester according to claim 7, characterized in that, The PWM duty cycle of the motor of the auger mechanism is preset with a first duty cycle, a second duty cycle, and a third duty cycle that increase in sequence; The rotation speed of the auger mechanism is preset with a first rotation speed, a second rotation speed, a third rotation speed, a fourth rotation speed, a fifth rotation speed, and a sixth rotation speed that increase in sequence; the third rotation speed is used as the initial rotation speed; The grain flow rate is preset with a first flow rate and a second flow rate that increase in sequence; When it is determined that a specific control mode needs to be entered: The control strategy of the high-load mode includes adjusting the PWM duty cycle of the auger mechanism to the third duty cycle and the rotation speed of the auger mechanism to the sixth rotation speed; controlling the second driving mechanism to raise the elevation angle of the second discharge chute to the corresponding preset value; controlling the first driving mechanism to keep the discharge port aligned with the center of the transport hopper; The control strategy of the energy-saving mode includes controlling the rotation speed of the auger mechanism within the range between the second rotation speed and the fourth rotation speed and keeping the second driving mechanism in the low-power mode; The control strategy of the anti-interference mode includes enabling overload protection for the motor of the auger mechanism, increasing the output torque of the motor by a preset ratio from the default value, controlling the second driving mechanism to lower the elevation angle of the second discharge chute to the corresponding preset value; calibrating the horizontal rotation angle of the first discharge chute every preset time interval to compensate for the offset caused by wind force or slope; When it is determined that a specific control mode does not need to be entered: If the grain flow rate is greater than the second flow rate, adjust the PWM duty cycle of the motor of the auger mechanism to the first duty cycle and the rotation speed to the first rotation speed; If the grain flow rate is greater than the first flow rate and less than the second flow rate, the auger mechanism maintains the current rotation speed unchanged; If the grain flow rate is less than the first flow rate, modulate the PWM duty cycle of the motor of the auger mechanism to the second duty cycle and the rotation speed to the fifth rotation speed.

9. The control method of a grain unloading system of a combine harvester according to claim 8, characterized in that, The control method further includes: If the grain flow rate is lower than the preset flow rate lower limit value and lasts for more than the corresponding preset time, reduce the rotation speed of the auger mechanism by a preset ratio every preset time interval until the rotation speed is reduced to the preset rotation speed lower limit value, and at the same time, lower the elevation angle of the second grain discharge chute by a preset angle every preset time interval until it returns to the zero position.

10. The control method of a grain unloading system of a combine harvester according to claim 8, characterized in that, The control method further includes: If the remaining amount in the granary detected by the granary remaining amount sensor is less than the preset remaining amount lower limit value, and the grain flow rate is zero and lasts for more than the corresponding preset time, send a stop signal to the auger mechanism; In response to the stop signal, the auger mechanism stops running and controls the first driving mechanism and the second driving mechanism to reset; The control of the first driving mechanism and the second driving mechanism to reset includes: Controlling the second driving mechanism to lower the elevation angle of the second grain discharge chute at the corresponding preset angular velocity until the initial zero position; Controlling the first driving mechanism to return the horizontal rotation angle of the first grain discharge chute to the initial zero position at the corresponding preset angular velocity; The control method further includes: If the horizontal rotation angle of the first grain unloading cylinder or the elevation angle of the second grain unloading cylinder deviates from the target angle by more than the corresponding preset threshold for a preset time, an action stop instruction is triggered to stop and maintain the current state; The control method further includes: If the grain coverage area in the real-time image of the transport vehicle hopper collected by the industrial camera at the grain unloading port is empty and the grain flow rate detected by the photoelectric sensor is above the corresponding preset threshold, an alarm instruction is triggered to prompt manual review of the industrial camera or cleaning of the lens; The control method further includes: An abnormal area with insufficient grain coverage in the transport vehicle hopper is obtained by processing the real-time image of the transport vehicle hopper collected by the industrial camera; According to the central coordinates of the abnormal area, the rotation angles of the first grain unloading cylinder and the second grain unloading cylinder are adjusted so that the grain unloading port is aligned with the abnormal area for grain unloading.

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