Method and apparatus for controlling the angle of a forage harvester

Abstract

The application discloses a kind of alfalfa harvester inclination control method and device, including pump body support, upper connecting lever, connecting rod frame, inclination adjustment solenoid valve, header hinged frame, controller, header, header support frame, inclination adjustment hydraulic cylinder, lower connecting lever, profile gear, angle sensor and straight gear, the upper connecting lever is hinged with support by rivet, the connecting rod frame is hinged with upper connecting lever by rivet, the inclination adjustment solenoid valve is connected to the front end of the connecting rod frame by bolt, the header hinged frame is welded to the front end of the connecting rod frame, and the header support frame is hinged with header hinged frame by rivet.The application can realize real-time adjustment of header inclination, can compensate header inclination, ensure stubble height uniformity, simple structure, low cost, without increasing complex measuring equipment, only increase an angle sensor, combined with the controller of harvesting machinery itself can realize header inclination adjustment, algorithm model is accurate, simple, reliable.

Description

Technical Field

[0001] This invention belongs to the field of agricultural machinery technology. Specifically, this invention relates to a method and device for controlling the tilt angle of an alfalfa harvester. Background Technology

[0002] Currently, there are three methods for implementing the contouring function in harvesters: mechanical, pneumatic-hydraulic, and electro-hydraulic. Mechanical and pneumatic-hydraulic contouring use springs and accumulators as elastic auxiliary components in the mechanism, respectively, in conjunction with a spatial linkage structure to achieve header contouring; however, this is a passive contouring method. Electro-hydraulic contouring uses different types of sensors, such as lasers, radar, and ultrasonic sensors, to collect header height information, and then uses controllers such as microcontrollers, PLCs, and Raspberry Pis to actively control the header height, thus achieving active contouring.

[0003] For mechanical and pneumatic-hydraulic contouring, contouring machinery has a simple structure, low cost, and stable and reliable operation; electro-hydraulic contouring, on the other hand, has a complex structure, high requirements for raw materials, high manufacturing costs, and inconvenient maintenance, making it unsuitable for low-cost mowers. Furthermore, forage harvesting machinery generally operates in complex environments such as natural and artificial pastures, where mechanical contouring is more favored by domestic and international manufacturers.

[0004] In mechanical contouring harvesters, the header is usually hinged to the harvester body through a four-bar linkage. The four-bar linkage causes the header to rotate around the instantaneous center of velocity, resulting in changes in the header's working height and tilt angle. The former ensures the header's contouring function, while the latter can cause changes in the stubble height, reduce the stability of the stubble height, and even cause the header to fall into the soil.

[0005] To compensate for changes in the tilt angle of the cutter head during mechanical contour cutting and to ensure a stable stubble height, a method and device for controlling the tilt angle of the cutter head that is responsive and reliable is needed. Summary of the Invention

[0006] This invention provides a method and device for controlling the tilt angle of an alfalfa harvester, which can realize real-time adjustment of the header tilt angle, compensate for the header tilt angle, and ensure uniform stubble height.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method and device for controlling the tilt angle of an alfalfa harvester, comprising a pump body support, an upper connecting rod, a connecting rod frame, a tilt angle adjusting solenoid valve, a header hinge frame, a controller, a header, a header support frame, a header tilt angle adjusting cylinder, a lower connecting rod, a special-shaped gear, an angle sensor, and a spur gear. The upper connecting rod is hinged to the support by rivets, the connecting rod frame is hinged to the upper connecting rod by rivets, the tilt angle adjusting solenoid valve is bolted to the front end of the connecting rod frame, and the header hinge frame is welded to the front end of the connecting rod frame. The cutting table support frame is hinged to the cutting table hinge frame by rivets. The controller is fixed to the upper end of the cutting table support frame by bolts. The cutting table is installed and fixed to the front end of the cutting table support frame. The two ends of the cutting table tilt adjustment cylinder are respectively hinged to the cutting table support frame and the cutting table hinge frame. The front end of the lower connecting rod is hinged to the connecting rod frame, and the rear end of the lower connecting rod is hinged to the bracket. The special gear is fixedly connected to the tail end of the lower connecting rod. The center of the spur gear is connected to the rotating shaft of the angle sensor, and the edge of the spur gear meshes with the special gear. The main body of the angle sensor is mounted on the bracket.

[0008] A control method for an alfalfa harvester tilt angle control device, comprising the following steps:

[0009] Step S1: Obtain the tilt angle of the cutting table under the current contouring action;

[0010] Step S2: Based on the current tilt angle and the target tilt angle, obtain the angle control deviation of the tilt angle of the cutting table;

[0011] Step S3: Based on the control deviation, output the extension and retraction adjustment amount of the cutting table tilt adjustment cylinder;

[0012] Step S4: Adjust the cutting table tilt angle according to the telescopic adjustment amount.

[0013] Preferably, step S1 specifically includes:

[0014] Obtain the first included angle β of the four-bar linkage under the current contouring action;

[0015] Calculate the first tilt angle α1 of the cutting table corresponding to the first included angle;

[0016] The first included angle is the angle between the lower connecting rod and the vertical plane in the four-bar linkage, and the first tilt angle is the angle between the cutting table and the horizontal plane.

[0017] Preferably, the specific calculation method for step S2 is as follows:

[0018] Based on the first tilt angle α1 and the target tilt angle α2 of the cutting table, the angle control deviation of the cutting table tilt angle is obtained. ɑ = ​​ɑ1 - ɑ2.

[0019] Preferably, step S3 specifically includes:

[0020] Set the preset starting adjustment amount;

[0021] Determine whether the absolute value of the angle control deviation is greater than the preset starting adjustment amount;

[0022] When the absolute value of the angle control deviation is greater than the preset starting adjustment amount, the controller outputs the extension length adjustment amount of the cutting table tilt adjustment cylinder. When the absolute value of the angle control deviation is less than the preset starting adjustment amount, the cutting table tilt angle remains in the current working state.

[0023] Preferably, step S4 specifically includes:

[0024] Determine if the stretch length adjustment is greater than zero;

[0025] When the stretching height adjustment is greater than zero, the cutting table tilt angle decreases;

[0026] When the stretching length adjustment is less than zero, the cutting table tilt angle increases.

[0027] The beneficial effects of adopting the above technical solutions are:

[0028] 1. This invention enables real-time adjustment of the header tilt angle, compensates for the header tilt angle, ensures uniform stubble height, has a simple structure and low cost, requires no additional complex measuring equipment, only an angle sensor, and can achieve header tilt angle adjustment by combining it with the controller built into the harvesting machinery. The algorithm model is accurate, simple and reliable.

[0029] 2. This invention obtains the angle control deviation of the cutter tilt angle based on the current tilt angle and the target tilt angle. The mathematical model of the cutter tilt angle established based on the four-bar structure parameters is accurate, simple and reliable.

[0030] 3. Based on the control deviation, the present invention outputs the extension and retraction adjustment amount of the cutting table tilt adjustment cylinder. The preset starting adjustment amount is the starting control threshold of the cutting table tilt adjustment solenoid valve. Only when the angle deviation is higher than the threshold will the control system start the adjustment; otherwise, the system will not respond, so as to avoid system instability caused by frequent adjustments.

[0031] 4. This invention adjusts the cutting table tilt angle based on the telescopic adjustment amount. When the telescopic adjustment amount is greater than zero, the cutting table tilt angle decreases; when the telescopic adjustment amount is less than zero, the cutting table tilt angle increases, thus improving the accuracy of angle adjustment. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the cutting table tilt angle control device of the present invention;

[0033] Figure 2 for Figure 1 A magnified view of a portion at point A shown;

[0034] Figure 3 This is a schematic flowchart of the cutting table tilt angle control method of the present invention. Figure 1 ;

[0035] Figure 4 This is a schematic flowchart of the cutting table tilt angle control method of the present invention. Figure 2 .

[0036] The markings in the diagram correspond to: 1. Bracket; 2. Upper connecting rod; 3. Connecting rod frame; 4. Tilt adjustment solenoid valve; 5. Cutting table hinge frame; 6. Controller; 7. Cutting table; 8. Cutting table support frame; 9. Cutting table tilt adjustment cylinder; 10. Lower connecting rod; 11. Irregular gear; 12. Angle sensor; 13. Spur gear. Detailed Implementation

[0037] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention, and to facilitate its implementation.

[0038] like Figures 1 to 4 As shown, this invention relates to a method and device for controlling the tilt angle of an alfalfa harvester, which can realize real-time adjustment of the header tilt angle, compensate for the header tilt angle, and ensure uniform stubble height.

[0039] Example 1

[0040] Specifically, such as Figures 1 to 4 As shown, the system includes a pump body support 1, an upper connecting rod 2, a connecting rod frame 3, a tilt adjustment solenoid valve 4, a header hinge frame 5, a controller 6, a header 7, a header support frame 8, a header tilt adjustment cylinder 9, a lower connecting rod 10, a special-shaped gear 11, an angle sensor 12, and a spur gear 13. The upper connecting rod 2 is hinged to the support 1 by rivets, and the connecting rod frame 3 is hinged to the upper connecting rod 2 by rivets. The tilt adjustment solenoid valve 4 is bolted to the front end of the connecting rod frame 3. The header hinge frame 5 is welded to the front end of the connecting rod frame 3, and the header support frame 8 is hinged to the header hinge frame 5 by rivets. The controller 6 is fixed to the upper end of the cutter support frame 8 by bolts. The cutter 7 is installed and fixed to the front end of the cutter support frame 8. The two ends of the cutter tilt adjustment cylinder 9 are respectively hinged to the cutter support frame 8 and the cutter hinge frame 5. The front end of the lower connecting rod 10 is hinged to the connecting rod frame 3, and the rear end of the lower connecting rod 10 is hinged to the bracket 1. The special gear 11 is fixedly connected to the tail end of the lower connecting rod 10. The center of the spur gear 13 is connected to the rotating shaft of the angle sensor 12. The edge of the spur gear 13 meshes with the special gear 11. The main body of the angle sensor 12 is installed on the bracket 1.

[0041] Example 2

[0042] A method for controlling the tilt angle of an alfalfa harvester, comprising the following steps:

[0043] Step S1: Obtain the tilt angle of the lower cutting table 7 in the current contouring action;

[0044] Step S2: Based on the current tilt angle of the cutting platform 7 and the target tilt angle, obtain the angle control deviation of the tilt angle of the cutting platform 7;

[0045] Step S3: Based on the control deviation, output the extension and retraction adjustment amount of the cutting table tilt adjustment cylinder 9;

[0046] Step S4: Adjust the tilt angle of the cutting table 7 according to the telescopic adjustment amount.

[0047] The specific content of step S1 is as follows:

[0048] Obtain the first included angle β of the four-bar linkage under the current contouring action;

[0049] Based on the first included angle, calculate the first tilt angle α1 of the cutting platform 7 corresponding to the first included angle;

[0050] The first included angle is the angle between the lower connecting rod 10 and the vertical plane in the four-bar linkage mechanism, and the first tilt angle is the angle between the cutting platform 7 and the horizontal plane.

[0051] The specific calculation method for step S2 is as follows:

[0052] Based on the first tilt angle α1 and the target tilt angle α2 of the cutting platform 7, the angle control deviation of the tilt angle of the cutting platform 7 is obtained as α = α1 - α2.

[0053] The specific content of step S3 is as follows:

[0054] Set the preset starting adjustment amount;

[0055] Determine whether the absolute value of the angle control deviation is greater than the preset starting adjustment amount;

[0056] When the absolute value of the angle control deviation is greater than the preset starting adjustment amount, the controller 6 outputs the extension length adjustment amount of the cutting table tilt adjustment cylinder 9. When the absolute value of the angle control deviation is less than the preset starting adjustment amount, the tilt angle of the cutting table 7 remains in the current working state.

[0057] The specific content of step S4 is as follows:

[0058] Determine if the stretch length adjustment is greater than zero;

[0059] When the extension height adjustment is greater than zero, the tilt angle of the cutting table 7 decreases;

[0060] When the stretching length adjustment is less than zero, the tilt angle of the cutting table 7 increases.

[0061] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other situations without modification, are all within the protection scope of the present invention.

Claims

1. An alfalfa harvester pitch control apparatus, characterized by: The device comprises a pump body support (1), an upper connecting rod (2), a connecting rod support (3), an inclination angle adjusting electromagnetic valve (4), a cutterbar hinged support (5), a controller (6), a cutterbar (7), a cutterbar support (8), a cutterbar inclination angle adjusting oil cylinder (9), a lower connecting rod (10), a profile gear (11), an angle sensor (12) and a straight gear (13). The upper connecting rod (2) is hinged to the support (1) by rivets, the connecting rod support (3) is hinged to the upper connecting rod (2) by rivets, the inclination angle adjusting electromagnetic valve (4) is connected to the front end of the connecting rod support (3) by bolts, the cutterbar hinged support (5) is welded to the front end of the connecting rod support (3), the cutterbar support (8) is hinged to the cutterbar hinged support (5) by rivets, the controller (6) is fixed on the upper end of the cutterbar support (8) by bolts, the cutterbar (7) is fixed on the front end of the cutterbar support (8), and the two ends of the cutterbar inclination angle adjusting oil cylinder (9) are hinged to the cutterbar support (8) and the cutterbar hinged support (5) respectively. The front end of the lower connecting rod (10) is hinged to the connecting rod support (3), the rear end of the lower connecting rod (10) is hinged to the support (1), the profile gear (11) is fixed to the tail end of the lower connecting rod (10), the center of the straight gear (13) is connected to the rotating shaft of the angle sensor (12), the edge of the straight gear (13) is engaged with the profile gear (11), and the main body of the angle sensor (12) is installed on the support (1).

2. A control method for the tilt control device of an alfalfa harvester according to claim 1, characterized in that: The specific steps are as follows: Step S1, obtaining the inclination angle of the cutterbar (7) under the current profiling action; Step S2, obtaining the angle control deviation of the inclination angle of the cutterbar (7) according to the current inclination angle of the cutterbar (7) and the target inclination angle; Step S3, outputting the extension adjustment amount of the cutterbar inclination angle adjusting oil cylinder (9) according to the control deviation; Step S4, adjusting the inclination angle of the cutterbar (7) according to the extension adjustment amount.

3. A control method for a tilt control device for an alfalfa harvester according to claim 2, characterized by: The specific content of step S1 is as follows: Obtaining the first included angle β of the four-bar linkage mechanism under the current profiling action; According to the first included angle, the first inclination angle ɑ1 of the cutterbar (7) corresponding to the first included angle is calculated; The first included angle is the included angle between the lower connecting rod (10) and the vertical plane in the four-bar linkage mechanism, and the first inclination angle is the included angle between the cutterbar (7) and the horizontal plane.

4. A control method for the control of the inclination of a harvester of alfalfa according to claim 3, characterized in that: The specific calculation method of step S2 is as follows: according to the first inclination angle ɑ1 of the cutterbar (7) and the target inclination angle ɑ2, the angle control deviation ɑ of the inclination angle of the cutterbar (7) is obtained, that is, ɑ=ɑ1-ɑ2.

5. The control method of the inclination angle control device of the alfalfa harvester according to claim 2, wherein the specific content of step S3 is as follows: setting a preset starting adjustment amount; determining whether the absolute value of the angle control deviation is greater than the preset starting adjustment amount; when the absolute value of the angle control deviation is greater than the preset starting adjustment amount, outputting the stretching length adjustment amount of the cutterbar inclination angle adjusting oil cylinder (9) by the controller (6), and when the absolute value of the angle control deviation is less than the preset starting adjustment amount, the inclination angle of the cutterbar remains in the current working state.

6. A control method for a tilt control device for an alfalfa harvester according to claim 5, characterized by: The specific content of step S4 is as follows: determining whether the stretching length adjustment amount is greater than zero; when the stretching length adjustment amount is greater than zero, the inclination angle of the cutterbar (7) becomes smaller; when the stretching length adjustment amount is less than zero, the inclination angle of the cutterbar (7) becomes larger.

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