Profiling adjusting device for header of corn harvester

Abstract

The invention discloses a profiling adjusting device for a header of a corn harvester. Wherein the rear part of the header is rotatably connected with the machine body, and the left and right sides of the bottom surface of the front part of the header are respectively provided with a profiling device; the control system is arranged in a cab; the attitude sensor used for collecting the rotation angle of the gap bridge around the fuselage is mounted on the gap bridge; the header is rotationally connected with the rotating seat; two ends of the hydraulic cylinder III are respectively hinged with the rotating seat and the header; the hydraulic cylinder I and the hydraulic cylinder II are arranged in parallel; two ends of the hydraulic cylinder I and the hydraulic cylinder II are respectively hinged with the rotating seat and the machine body; and the cutting knife is fixed below the middle front part of the header. The risk that the header touches the ground and is damaged can be well reduced, the operation difficulty is reduced, and the automatic corn harvesting degree is improved. The device is used for detecting the height of the header from the ground, is simple in structure, is convenient to install, is higher in anti-interference capability, and can well adapt to a complex working environment.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural machinery, and in particular relates to a cutting table profiling adjustment device for a corn harvester. Background Art

[0002] Corn is one of the three major food crops in my country and plays a very important role in my country's food security and agricultural development. However, in corn fields in hilly and mountainous areas with many slopes, small and scattered cultivated land, and low mechanization, existing plain corn harvesters are difficult to use directly. Local corn harvesting is still mainly manual, with low harvesting efficiency.

[0003] During the mechanized corn harvesting process, 75% of the harvest losses are caused by the header, most of which are caused by unreasonable header height adjustment. Improper header height adjustment will directly lead to harvest losses and header damage.

[0004] At present, most of the harvester cutting table height adjustment methods in China are still manual adjustment, and the adjustment accuracy and speed are limited. Summary of the invention

[0005] Aiming at the problems caused by the improper adjustment of the height of the cutting platform and the sloped cultivated land in the hilly and mountainous areas, the present invention provides a cutting platform profiling adjustment device for a corn harvester, which can realize the accurate detection and adaptive adjustment of the cutting platform height. The technical scheme includes: a fuselage, a cutting platform, a profiling device, a control system and a hydraulic device, wherein the rear of the cutting platform is rotatably connected with the fuselage, and a profiling device is respectively installed on the left and right sides of the bottom surface of the front part of the cutting platform; the control system is arranged in the cab; the attitude sensor for collecting the rotation angle of the bridge around the fuselage is installed on the bridge;

[0006] The cutting table and the rotating seat are rotatably connected, and the two ends of the hydraulic cylinder III are respectively hinged with the rotating seat and the cutting table; the hydraulic cylinder I and the hydraulic cylinder II are arranged in parallel, and the two ends of the hydraulic cylinder I and the hydraulic cylinder II are respectively hinged with the rotating seat and the machine body; the cutting knife is fixed at the lower part of the middle front of the cutting table;

[0007] The profiling device comprises: a fixed bracket, a coupling, an angle sensor, a profiling plate, a flange bearing and a torsion spring, wherein the profiling plate shaft of the profiling plate is connected to the fixed bracket through a bearing, the torsion spring hook I of the torsion spring is connected to the profiling plate spring hanging shaft of the profiling plate, and the torsion spring hook II of the torsion spring is connected to the torsion spring fixing hole group of the profiling plate; the arc portion at the lower end of the profiling plate contacts the ground; the housing of the angle sensor is fixed to the fixed bracket, and the measuring portion of the angle sensor is connected to the profiling plate shaft through a coupling.

[0008] The manner in which the profiling plate shaft and the fixed bracket are connected through bearings is as follows: the outer side of the flange bearing is connected to the bearing protection shell through interference fit, and the inner side of the flange bearing is connected to the profiling plate shaft through interference fit; the bearing protection shell is connected to the flange bearing fixing through hole I, flange bearing fixing through hole II, flange bearing fixing through hole III and flange bearing fixing through hole IV on the fixed bracket through bolts.

[0009] The angle sensor housing is fixed to the fixing bracket in the following manner: the angle sensor housing is connected to the angle sensor fixing through hole I, the angle sensor fixing through hole II and the angle sensor fixing through hole III on the fixing bracket by bolts.

[0010] The torsion spring hook II is inserted into one of the torsion spring fixing through hole I, the torsion spring fixing through hole II, the torsion spring fixing through hole III or the torsion spring fixing through hole IV in the torsion spring fixing hole group, thereby being connected to the fixing bracket to adjust the tightness.

[0011] A chain hole for installing a chain is provided at the end of the arc portion.

[0012] The arc-shaped portion faces rearward.

[0013] The hydraulic device comprises a hydraulic cylinder I, a hydraulic cylinder II, a throttle valve I, a check valve I, a hydraulically controlled check valve I, a hydraulically controlled check valve II, an electromagnetic reversing valve I, a check valve II, a hydraulic pump, a motor, a filter, an oil tank, an overflow valve, an electromagnetic reversing valve II, a hydraulically controlled check valve III, a hydraulically controlled check valve IV, a check valve III, a throttle valve II and a hydraulic cylinder III; wherein the oil tank is sequentially connected through the filter, the hydraulic pump and the inlet of the check valve II, the outlet of the check valve II and the outlet of the overflow valve are merged and enter the first interface of the electromagnetic reversing valve I and the first interface of the electromagnetic reversing valve II respectively, the electromagnetic reversing valve I The second interface of is connected to one end of hydraulic cylinder Ⅰ and hydraulic cylinder Ⅱ respectively through hydraulic control one-way valve Ⅱ, the third interface of is connected to throttle valve Ⅰ and one-way valve Ⅰ respectively through hydraulic control one-way valve Ⅰ, throttle valve Ⅰ and one-way valve Ⅰ are connected to the other end of hydraulic cylinder Ⅰ and hydraulic cylinder Ⅱ after merging; the second interface of electromagnetic reversing valve Ⅱ is connected to one end of hydraulic cylinder Ⅲ after passing through hydraulic control one-way valve Ⅲ, the third interface of electromagnetic reversing valve Ⅱ is connected to one-way valve Ⅲ and throttle valve Ⅱ respectively through hydraulic control one-way valve Ⅳ, one-way valve Ⅲ and throttle valve Ⅱ are connected to the second end of hydraulic cylinder Ⅲ after merging; the hydraulic pump is connected to the motor.

[0014] The control scheme of the header in the control system includes the following situations:

[0015] 1) Lowering: When the left and right profiling devices detect that the height of the header on both sides is higher than the upper limit of the height threshold interval in the up-down direction, the hydraulic cylinders I and II are controlled to contract, so that the header height is lowered in the up-down direction until it stabilizes within the set height threshold interval;

[0016] 2) Raising: When one of the left and right profiling devices detects that the height of the header is lower than the lower limit of the height threshold interval in the up-down direction, the hydraulic cylinders I and II are controlled to extend so that the header height is raised in the up-down direction until it stabilizes within the set up-down threshold interval;

[0017] 3) No lifting: When the profiling devices on both sides detect that the height of the header on that side is within the height threshold range, the header is not adjusted up and down, and the hydraulic cylinders I and II are controlled to be stationary, and the header is not adjusted up and down;

[0018] 4) Rotation: When the height detected by the profiling device on one side is greater than the height detected by the profiling device 1 on the other side, and the difference is greater than the rotation threshold, the hydraulic cylinder III is controlled to contract / extend, so that the cutting table 9 rotates around the cutting table rotation point, the height on one side decreases, and the height on the other side increases; until the height difference between the two sides is stabilized within the set left and right direction range.

[0019] 5) No rotation: When the height difference detected by the profiling devices on both sides is within the set rotation threshold, the left and right directions of the header are not adjusted.

[0020] Height detected by the profiling device R is the height from the center of the arc to the ground, L is the straight-line distance from the rotation center of the profiling plate to the center of the arc touching the ground, is the measured value of the angle sensor, is regarded as the angle between the profiling plate and the line connecting the rotation center of the profiling plate and the rotation center of the bridge 5; α is the measurement value of the attitude sensor; It is the angle between the contour plate and the line connecting its rotation center and the center of the touchdown arc.

[0021] The information collected by the angle sensor is subjected to noise filtering by a profiling device noise correction Kalman recursive algorithm, and the profiling device noise correction Kalman recursive algorithm includes:

[0022] A priori estimate:

[0023]

[0024] A priori estimated covariance:

[0025] P t - =FP t-1 F T +Q (3-2)

[0026] Update the Kalman gain:

[0027] K t =P t -H T (HP t - H T +R) -1 (3-3)

[0028] Revised Estimates:

[0029]

[0030] Update the posterior estimated covariance:

[0031] P t =(IK t H)P t - (3-5)

[0032] Among them, F is the state transfer matrix, B is the control matrix, U t-1 is the process control variable, Q is the variance of process noise, which affects the accuracy of the predicted value, R is the variance of observation noise, which affects the accuracy of the observed value, H is the observation matrix, and is a constant; Zt is the observed variable with noise removed as the measurement value of the angle sensor at this moment K t is the Kalman gain.

[0033] The beneficial effects of the present invention are:

[0034] 1. The present invention effectively improves the adaptability of corn harvesters to hilly and mountainous areas with gentle slopes, improves corn harvesting efficiency, and can also well reduce the risk of the header touching the ground and being damaged, reduce the difficulty of operation, and improve the degree of automatic corn harvesting. It is used to detect the height of the header from the ground, has a simple structure, is easy to install, has stronger anti-interference ability, and can well adapt to complex working environments.

[0035] 2. The bottom of the designed profiling plate is in contact with the ground when working. The real-time height of the cutting platform can be obtained by measuring its rotation angle. While adjusting the height of the cutting platform, the stubble height can also be monitored.

[0036] 3. The bottom of the designed profiling plate is arc-shaped, which can effectively reduce the resistance of the profiling plate when rotating, and also reduce the impact of the profiling plate when reversing, so that the profiling device has better passability.

[0037] 4. The designed profiling plate can rotate at a large angle, which can better pass through obstacles. At the same time, a hanging chain is designed at the tail to limit the angle and prevent the profiling device from being damaged.

[0038] 5. The designed profiling device is installed on the left and right sides of the bottom of the front part of the header to achieve early profiling, which can well adapt to the harvesting of corn on the slope and prevent the header from touching the ground due to untimely adjustment.

[0039] 6. A height threshold interval control scheme and an adjustment strategy to prevent the header from touching the ground are designed, which effectively filters out the influence of field weeds and small ditches, effectively prevents the header from touching the ground, and increases the stability of the contour adjustment device. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is an overall schematic diagram of an embodiment of a corn harvester header profiling adjustment device of the present invention;

[0041] Figure 2 Schematic diagram of the structure of the profiling device in the embodiment of the present invention

[0042] Figure 3 Schematic diagram of a fixing bracket for a profiling plate according to an embodiment of the present invention;

[0043] Figure 4 Schematic diagram of the structure of the profiling plate in the embodiment of the present invention;

[0044] Figure 5 is a schematic diagram of the structure of a torsion spring in an embodiment of the present invention;

[0045] Figure 6 is a block diagram of a control system in an embodiment of the present invention;

[0046] Figure 7 is a flow chart of Kalman filtering in an embodiment of the present invention;

[0047] Figure 8 It is a diagram of a hydraulic system for lifting a cutting platform in an embodiment of the present invention;

[0048] Fig. 9 It is a flow chart of the control scheme in an embodiment of the present invention.

[0049] Among them, 1- profiling device; 2- cutting knife; 3- attitude sensor; 4- hydraulic system; 5- bridge; 6- fuselage; 7- operating table; 8- control system; 9- cutting table; 11- fixed bracket; 12- coupling; 13- angle sensor; 14- profiling plate; 15- flange bearing; 16- torsion spring; 17- rotating seat; 111- fixed bracket fixing through hole Ⅰ; 112- fixed bracket fixing through hole Ⅱ; 113- angle sensor fixing through hole Ⅰ; 114- angle sensor fixing through hole Ⅱ; 115- angle sensor fixing through hole Ⅲ; 116- through hole Ⅰ; 117- through hole Ⅱ; 118- flange bearing fixing through hole Ⅰ; 119- flange bearing fixing through hole Ⅱ; 120- flange bearing fixing through hole Ⅲ; 121- flange bearing fixing through hole Ⅳ; 120- torsion spring fixing hole group; 1 22-torsion spring fixing hole Ⅰ; 123-torsion spring fixing hole Ⅱ; 124-torsion spring fixing hole Ⅲ; 125-torsion spring fixing hole Ⅳ; 141-profile plate shaft; 142-hanging chain hole; 143-profile plate spring hanging shaft; 144-arc-shaped part; 161-torsion spring hook Ⅰ; 162-torsion spring hook Ⅱ; 31-hydraulic cylinder Ⅰ; 32-hydraulic cylinder Ⅱ; 33-throttle Valve Ⅰ; 34- one-way valve Ⅰ; 35- hydraulically controlled one-way valve Ⅰ; 36- hydraulically controlled one-way valve Ⅱ; 37- electromagnetic reversing valve Ⅰ; 38- one-way valve Ⅱ; 39- hydraulic pump; 40- motor; 41- filter; 42- oil tank; 43- overflow valve; 44- electromagnetic reversing valve Ⅱ; 45- hydraulically controlled one-way valve Ⅲ; 46- hydraulically controlled one-way valve Ⅳ; 47- one-way valve Ⅲ; 48- throttle valve Ⅱ; 49- hydraulic cylinder Ⅲ. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0051] like Figure 1 to Figure 6 The embodiment of the present invention shown in the figure comprises: a fuselage 6, a cutting platform 9, a profiling device 1, a control system 8 and a hydraulic device 3, wherein the rear portion of the cutting platform 9 is rotatably connected to the fuselage 6, so that the cutting platform 9 can be rotated so that its front end can be displaced up and down; a profiling device 1 is respectively installed on the left and right sides of the bottom surface of the front portion of the cutting platform 9, for detecting the real-time height of the cutting platform 9 and the ground; a cab 7 is arranged at the front portion of the fuselage 6, and a control system 8 is arranged in the cab 7, for the driver to send operating instructions and observe parameter information of the cutting platform 9 at the same time;

[0052] The cutting table 9 and the rotating seat 17 are rotatably connected, and the two ends of the hydraulic cylinder III 49 are respectively hinged to the rotating seat 17 and the cutting table 9, thereby serving as an actuator to control the relative height of the two sides of the cutting table 9; the hydraulic cylinder I 31 and the hydraulic cylinder II 32 are arranged in parallel, and the two ends of the hydraulic cylinder I 31 and the hydraulic cylinder II 32 are respectively hinged to the rotating seat 17 and the fuselage 6, thereby adjusting the height of the front end of the cutting table 9 from the ground as an actuator; the cutting knife 2 is fixed at the lower part of the front middle part of the cutting table 9.

[0053] like Figure 2 The profiling device 1 shown comprises: a fixed bracket 11, a coupling 12, an angle sensor 13, a profiling plate 14, a flange bearing 15 and a torsion spring 16, wherein a profiling plate shaft 141 of the profiling plate 14 is connected to the fixed bracket 11 via a bearing, a torsion spring hook I 161 of the torsion spring 16 is connected to a profiling plate spring hanging shaft 143 of the profiling plate 14, and a torsion spring hook II 162 of the torsion spring 16 is connected to a torsion spring fixing hole group 120 of the profiling plate 14; an arc-shaped portion 144 at the lower end of the profiling plate 14 contacts the ground; a housing of the angle sensor 13 is fixed to the fixed bracket 11, and a measuring portion of the angle sensor 13 is connected and fixed to the profiling plate shaft 141 via a coupling 12 so as to rotate together;

[0054] In this embodiment, the profiling plate shaft 141 is connected to the fixed bracket 11 through the bearing in the following manner: the outer side of the flange bearing 15 is connected to the bearing protection shell through interference fit, and the inner side of the flange bearing 15 is connected to the profiling plate shaft 141 through interference fit; the bearing protection shell is connected to the flange bearing fixing through hole I118, the flange bearing fixing through hole II119, the flange bearing fixing through hole III120 and the flange bearing fixing through hole IV121 on the fixed bracket 11 through bolts;

[0055] In this embodiment, the housing of the angle sensor 13 is fixed to the fixing bracket 11 in the following manner: the housing of the angle sensor 13 is connected to the angle sensor fixing through hole I 113, the angle sensor fixing through hole II 114 and the angle sensor fixing through hole III 115 on the fixing bracket 11 by bolts;

[0056] In this embodiment, the torsion spring hook II 162 can be selectively inserted into one of the torsion spring fixing through hole I 122, the torsion spring fixing through hole II 123, the torsion spring fixing through hole III 124 or the torsion spring fixing through hole IV 125 in the torsion spring fixing hole group 120, thereby connecting with the fixing bracket 11 to adjust the tightness.

[0057] like Figure 1 The arc portion 144 of the profiling device 1 shown faces backward, and the arc portion 144 of the profiling plate 14 is always in close contact with the ground under the action of the torsion spring 16. As the ground rises and falls, the profiling plate 14 rotates around the flange bearing 15. Hilly and mountainous areas are suitable for small-width corn harvesters, and the harvesting width is 3 to 4 rows. If a single profiling device 1 is used, the error of the height collection information of the cutting table 9 will be large, resulting in inaccurate height adjustment of the cutting table 9. If multiple profiling devices 1 are used, the system will be more complicated, and the installation space of the cutting table 9 is limited. Therefore, two sets of identical profiling devices 1 are designed on a horizontal plane perpendicular to the forward direction, and are arranged on the left and right sides of the cutting table 9 respectively.

[0058] In this embodiment, if Figure 1 As shown, the attitude sensor 3 is installed on the bridge 5 and is connected by screws. It is responsible for collecting the rotation angle of the bridge 5 around the fuselage 6.

[0059] In this embodiment, a chain hole 142 for installing a chain is provided at the end of the arc-shaped portion 144, so that the profiling device 1 can be lifted off the ground when it is not needed.

[0060] The method for collecting the height of the header 9 from the ground by collecting the angle information of the profiling plate includes: by analyzing the structural characteristics of the profiling adjustment device of the header of the corn harvester, a mathematical relationship between the angle sensor 13 and the posture sensor 3 and the height of the header 9 is established: Where Ha is the simulated height of the cutting table 9 from the ground as the height detected by the profiling device 1; R is the height of the center of the arc portion 144 from the ground; L is the straight-line distance from the rotation center of the profiling plate 14 to the center of the arc touching the ground, is the measured value of the angle sensor 13, is regarded as the angle between the profiling plate 14 and the line connecting the rotation center of the profiling plate 14 and the rotation center of the bridge 5; α is the measurement value of the attitude sensor 3, and α is regarded as the horizontal plane angle of the bridge 5; The angle between the profiling plate 14 and the line connecting the center of rotation of the profiling plate 14 and the center of the arc touching the ground is a fixed value. Therefore, the information detection of the simulated height above the ground of the cutting platform 9 can be realized by collecting the rotation angle of the profiling plate 14.

[0061] like Figure 6 The control system 8 shown includes: a single-chip development board 81, a touch screen 82, a programming device 83, a computer 84 and a relay 85. The touch screen 82 is responsible for inputting driver commands and displaying real-time parameter information of the header 9. The programming device 83 and the computer 84 realize the software development of the control system 8. The relay 85 is responsible for executing the output instructions of the single-chip development board 81.

[0062] In view of the problems of harsh working environment, many interference factors such as weeds, etc., a filtering method for collecting information from the angle sensor 13 is provided, and the Kalman filtering algorithm is used to filter the noise of the collected angle information; the filtering process flowchart is shown in FIG. Figure 7 As shown in the figure, F is the state transfer matrix, B is the control matrix, and U t-1 is the process control variable, Q is the variance of the process noise, which affects the accuracy of the predicted value, R is the variance of the observation noise, which affects the accuracy of the observation value, H is the observation matrix, is a constant, and Zt is the observation variable with the noise removed as the measurement value of the angle sensor 13 at this moment

[0063] The corresponding noise correction Kalman recursive algorithm for the profiling equipment using the angle sensor is to apply the Kalman filter concept to the acquisition of the profiling device angle. The variance of the process noise and the observation noise is obtained by experimental test. The angle value at time t is predicted based on the optimal angle value and covariance at time t-1. The interference of the fuselage vibration, ground weeds, etc. is considered, the variance Q of the process noise is added, the covariance is predicted, and the error R existing in the sensor itself is considered. The Kalman gain is updated, and the updated Kalman gain K t The predicted value and the observed value Z t The optimal solution at time t is obtained by fusion, and the angle measurement value at time t is "corrected" by the predicted value of the angle at time t, so as to obtain the angle information close to the true value after filtering out the external interference. The Kalman recursive algorithm for profiling equipment noise correction includes:

[0064] A priori estimate:

[0065]

[0066] A priori estimated covariance:

[0067] P t - =FP t-1 F T +Q (3-7)

[0068] Update the Kalman gain:

[0069] K t =P t - H T (HP t - H T +R) -1 (3-8)

[0070] Revised Estimates:

[0071]

[0072] Update the posterior estimated covariance:

[0073] P t =(IK t H)P t - (3-10)

[0074] Then continue to collect the angle information at the next moment and perform the same profiling device noise correction Kalman recursive algorithm.

[0075] During the actual operation of the header profiling adjustment device, due to the influence of external interference and the sensor's own errors, the angle acquisition value will fluctuate more than the true value. At the same time, due to the uncertainty and inevitability of these interferences, it is difficult to reduce the error by improving the hardware device. Therefore, data fusion is used to correct the acquisition value, so as to reduce external interference and eliminate jitter.

[0076] like Figure 8 The hydraulic oil circuit of the cutting platform height adjustment part shown in the figure, the hydraulic device 3 includes hydraulic cylinder I 31, hydraulic cylinder II 32, throttle valve I 33, non-return valve I 34, hydraulically controlled non-return valve I 35, hydraulically controlled non-return valve II 36, solenoid reversing valve I 37, non-return valve II 38, hydraulic pump 39, motor 40, filter 41, oil tank 42, overflow valve 43, solenoid reversing valve II 44, hydraulically controlled non-return valve III 45, hydraulically controlled non-return valve IV 46, non-return valve III 47, throttle valve II 48, hydraulic cylinder III 49. Among them, hydraulic cylinder I 31 and hydraulic cylinder II 32 are responsible for adjusting the height of the front end of the cutting platform 9, and hydraulic cylinder III 49 is responsible for adjusting the angle of the cutting platform 9 in the left and right directions; the oil tank 42 is connected to the inlet of the filter 41, the hydraulic pump 39 and the one-way valve II 38 in sequence, and the outlet of the one-way valve II 38 and the outlet of the overflow valve 43 are merged and enter the first interface of the electromagnetic reversing valve I 37 and the first interface of the electromagnetic reversing valve II 44 respectively. The second interface of the electromagnetic reversing valve I 37 is connected to one end of the hydraulic cylinder I 31 and the hydraulic cylinder II 32 respectively through the hydraulic control one-way valve II 36, and the third interface of 37 Through the hydraulically controlled one-way valve Ⅰ35, it is respectively connected to the throttle valve Ⅰ33 and the one-way valve Ⅰ34. After the throttle valve Ⅰ33 and the one-way valve Ⅰ34 are merged, they are connected to the other end of the hydraulic cylinder Ⅰ31 and the hydraulic cylinder Ⅱ32; the second interface of the electromagnetic reversing valve Ⅱ44 is connected to one end of the hydraulic cylinder Ⅲ49 after passing through the hydraulically controlled one-way valve Ⅲ45, and the third interface of 44 is respectively connected to the one-way valve Ⅲ47 and the throttle valve Ⅱ48 through the hydraulically controlled one-way valve Ⅳ46. After the one-way valve Ⅲ47 and the throttle valve Ⅱ48 are merged, they are connected to the second end of the hydraulic cylinder Ⅲ49; the hydraulic pump 39 is connected to the motor 40 to drive it to rotate.

[0077] When the electromagnetic reversing valve I37 works in the right position, the hydraulic oil passes through the hydraulic control check valve I35, check valve I34, hydraulic cylinder I31, hydraulic cylinder II32, hydraulic control check valve II36 and oil tank in sequence along the left oil circuit, thereby extending the hydraulic cylinder I31 and hydraulic cylinder II32, so that the front end of the cutting platform is raised. When the electromagnetic reversing valve I37 works in the left position, the hydraulic oil passes through the hydraulic control check valve II36, hydraulic cylinder I31, hydraulic cylinder II32, throttle valve I33, hydraulic control check valve I35 and oil tank in sequence, thereby contracting the hydraulic cylinder I31 and hydraulic cylinder II32, so that the front end of the cutting platform is lowered. In this process, the throttle valve 33 generates a circuit back pressure to balance the gravity of the cutting platform 9 and prevent oscillation when it is lowered. When the electromagnetic reversing valve 37 is in the middle position, the oil inlet is blocked, the residual hydraulic oil in the circuit returns to the oil tank 38, and the hydraulic control check valve I 35 and the hydraulic control check valve II 36 remain closed, so that the cutting platform 9 can stay reliably for a long time without falling. The hydraulic cylinder III 49 is installed on one side of the cutting platform 9. The adjustment principle is the same as the height adjustment principle of the cutting platform in the up and down direction. The right tilt and left tilt of the cutting platform 9 are achieved through the extension and contraction of the piston rod, thereby achieving the adjustment of the left and right height of the cutting platform 9.

[0078] The present invention provides a control scheme for a threshold interval of a stable height of the cutting platform. When the height of the cutting platform is within the threshold interval, the height of the cutting platform is not adjusted. When the collected height of the cutting platform exceeds the threshold interval, the height of the cutting platform in two directions is quickly adjusted to stabilize the height within the threshold interval. This can realize the adjustment of the overall height of the cutting platform and the adjustment of the left and right heights of the cutting platform.

[0079] In view of the large number of small undulations such as ditches, ridges, and weeds in the fields of hilly and mountainous areas, the present invention provides an adjustment method based on a threshold range control scheme for the adjustment device as described in an embodiment in order to reduce the number of adjustments and improve the stability of the system. The adjustment method simultaneously adjusts the upper and lower heights and the left and right heights of the cutting platform 9, and the adjustments in the two directions do not interfere with each other. It can effectively prevent the cutting platform from touching the ground and damage, increase the stability of the adjustment of the cutting platform, make the heights of the left and right sides close to the ground, and thus make the stubble height consistent. The control scheme process is as follows Fig. 9 The specific plan is as follows:

[0080] (1) Lowering: When the left and right side profiling devices 1 detect that the height of the cutting platform 9 on both sides is higher than the upper limit of the height threshold interval in the up-down direction, the hydraulic cylinders I 31 and II 32 are controlled to contract, so that the height of the cutting platform 9 is lowered in the up-down direction until it stabilizes within the set up-down direction height threshold interval.

[0081] (2) Raising: When one of the left and right profiling devices 1 detects that the height of the cutting platform 9 is lower than the lower limit of the height threshold interval in the up-down direction, the hydraulic cylinders I 31 and II 32 are controlled to extend so that the height of the cutting platform is raised in the up-down direction until it stabilizes within the set up-down threshold interval; at this time, regardless of the height of the cutting platform 9 detected by the profiling device 1 on the other side, the cutting platform 9 is raised in the up-down direction.

[0082] (3) No lifting: When the profiling devices 1 on both sides detect that the height of the cutting platform 9 on the side is within the height threshold range, the cutting platform 9 is not adjusted in the up and down direction, and the hydraulic cylinders I 31 and II 32 are controlled to be stationary, and the cutting platform 9 is not adjusted in the up and down direction. This can effectively prevent the interference of some stubble, gullies, etc. from causing the cutting platform 9 to have an instantaneous impact, causing the cutting platform 9 to touch the ground.

[0083] (4) Rotation: When the height detected by the profiling device 1 on the first side is greater than the height detected by the profiling device 1 on the second side, and the difference is greater than the rotation threshold, the hydraulic cylinder III 49 is controlled to contract / extend, so that the cutting table 9 rotates around the cutting table rotation point, the height of the first side is reduced, and the height of the second side is increased; until the height difference between the two sides is stabilized within the set left and right direction range.

[0084] (5) No rotation: When the height difference detected by the profiling devices 1 on both sides is within the set rotation threshold, the left and right directions of the header are not adjusted.

[0085] In the automatic adjustment mode, the height threshold, rotation threshold and initial posture information of the header 9 are input through the touch screen 82, and the control system 8 starts to receive the collected information of the angle sensor 13 and the posture sensor 3, and converts the analog signal into a discrete digital signal recognizable by the single-chip development board 81 through the ADC module, filters out the interference signal, and converts the collected angle information into the header 9 height information, and executes the adjustment method based on the threshold interval control scheme of the upper adjustment device:

[0086] The control system 8 can realize the control of the connection or disconnection of the relay 85 contacts by outputting different high and low levels, wherein the relay 85 is effective when the high level is high, that is, when the electrical signal to one of the ports is high, the corresponding contact switch remains in a closed state, and the circuit on this side of the electromagnetic reversing valve 37 is turned on. The electromagnetic force generated by the electromagnetic coil is used to push the valve core to switch, realize the switching of the hydraulic oil circuit, realize the extension or contraction of the hydraulic cylinder I 31 and the hydraulic cylinder II 32, and realize the raising or lowering of the cutting platform. The information collected by the angle sensor 13 and the attitude sensor 3 is updated in real time, the calculation of the control system 8 is updated in real time, and the height of the cutting platform 9 is adjusted in real time, thereby realizing the closed-loop feedback adjustment of the height of the cutting platform. When pausing, stopping or changing the working mode, just click the button corresponding to the touch screen 82.

[0087] The present invention obtains the horizontal angle of the profiling plate by collecting the rotation angle of the profiling plate and the inclination angle information of the bridge, establishes the mathematical relationship between the horizontal angle of the profiling plate and the height of the profiling plate rotation center from the ground, thereby obtaining the real-time height information of the cutting platform; based on the single-chip microcomputer design control scheme and adjustment strategy, the hydraulic oil circuit of the lifting part of the cutting platform is designed, and the relay is controlled by the single-chip microcomputer to realize the switching of the hydraulic oil circuit, the extension and contraction of the hydraulic cylinder, and the adaptive adjustment of the height of the cutting platform. The adaptive adjustment of the height of the corn harvester cutting platform is realized, the harvesting efficiency is improved, the harvesting effect is improved, the harvesting loss is reduced, and the labor force is liberated; at the same time, the risk of the corn harvester cutting platform touching the ground and being damaged can be reduced, and the adaptability of the corn harvester under the complex slope working conditions in hilly and mountainous areas can be improved, and at the same time, it has good economic benefits.

Claims

1. A corn harvester header profiling adjustment device, characterized in that: include: A fuselage (6), a cutting platform (9), a profiling device (1), a control system (8) and a hydraulic device (3), wherein the rear of the cutting platform (9) is rotatably connected to the fuselage (6), and a profiling device (1) is respectively installed on the left and right sides of the bottom surface of the front part of the cutting platform (9); the control system (8) is arranged in the cab (7); and a posture sensor (3) for collecting the rotation angle of the bridge (5) around the fuselage (6) is installed on the bridge (5); The cutting platform (9) and the rotating seat (17) are rotatably connected, and the two ends of the hydraulic cylinder III (49) are respectively hinged to the rotating seat (17) and the cutting platform (9); the hydraulic cylinder I (31) and the hydraulic cylinder II (32) are arranged in parallel, and the two ends of the hydraulic cylinder I (31) and the hydraulic cylinder II (32) are respectively hinged to the rotating seat (17) and the machine body (6); the cutting knife (2) is fixed below the front middle part of the cutting platform (9); The profiling device (1) comprises: a fixed bracket (11), a coupling (12), an angle sensor (13), a profiling plate (14), a flange bearing (15) and a torsion spring (16); a profiling plate shaft (141) of the profiling plate (14) is connected to the fixed bracket (11) through a bearing; a torsion spring hook I (161) of the torsion spring (16) is connected to a profiling plate spring hanging shaft (143) of the profiling plate (14); a torsion spring hook II (162) of the torsion spring (16) is connected to a torsion spring fixing hole group (120) of the profiling plate (14); an arc-shaped portion (144) at the lower end of the profiling plate (14) contacts the ground; a housing of the angle sensor (13) is fixed to the fixed bracket (11); and a measuring portion of the angle sensor (13) is connected to the profiling plate shaft (141) through a coupling (12).

2. A corn harvester header profiling adjustment device according to claim 1, characterized in that: The profiling plate shaft (141) is connected to the fixed bracket (11) via the bearing in the following manner: the outer side of the flange bearing (15) is connected to the bearing protection shell via interference fit, and the inner side of the flange bearing (15) is connected to the profiling plate shaft (141) via interference fit; the bearing protection shell is connected to the flange bearing fixing through hole I (118), the flange bearing fixing through hole II (119), the flange bearing fixing through hole III (120) and the flange bearing fixing through hole IV (121) on the fixed bracket (11) via bolts.

3. The corn harvester header profiling adjustment device according to claim 1, characterized in that: The housing of the angle sensor (13) is fixed to the fixing bracket (11) in the following manner: the housing of the angle sensor (13) is connected to the angle sensor fixing through hole I (113), the angle sensor fixing through hole II (114) and the angle sensor fixing through hole III (115) on the fixing bracket (11) by means of bolts.

4. The corn harvester header profiling adjustment device according to claim 1, characterized in that: The torsion spring hook II (162) is inserted into one of the torsion spring fixing through hole I (122), the torsion spring fixing through hole II (123), the torsion spring fixing through hole III (124) or the torsion spring fixing through hole IV (125) in the torsion spring fixing hole group (120), thereby being connected to the fixing bracket (11) to adjust the tightness.

5. The corn harvester header profiling adjustment device according to claim 1, characterized in that: The end of the arc-shaped portion (144) is provided with a hanging chain hole (142) for installing a hanging chain.

6. A corn harvester header profiling adjustment device according to claim 1 or 5, characterized in that: The arc-shaped portion (144) faces rearward.

7. The corn harvester header profiling adjustment device according to claim 1, characterized in that: The hydraulic device (3) comprises a hydraulic cylinder I (31), a hydraulic cylinder II (32), a throttle valve I (33), a check valve I (34), a hydraulically controlled check valve I (35), a hydraulically controlled check valve II (36), an electromagnetic reversing valve I (37), a check valve II (38), a hydraulic pump (39), a motor (40), a filter (41), an oil tank (42), an overflow valve (43), an electromagnetic reversing valve II (44), a hydraulically controlled check valve III (45), a hydraulically controlled check valve IV (46), a check valve III (47), a throttle valve II (48) and a hydraulic cylinder III (49); wherein the oil tank (42) is connected in sequence through the filter (41), the hydraulic pump (39) and the inlet of the check valve II (38), and the outlet of the check valve II (38) and the outlet of the overflow valve (43) are merged and enter the first interface of the electromagnetic reversing valve I (37) and the first interface of the electromagnetic reversing valve II (44) respectively. The second interface of the electromagnetic reversing valve I (37) is connected to one end of the hydraulic cylinder I (31) and the hydraulic cylinder II (32) through the hydraulic control check valve II (36), and the third interface of the electromagnetic reversing valve (37) is connected to the throttle valve I (33) and the check valve I (34) through the hydraulic control check valve I (35). The throttle valve I (33) and the check valve I (34) are connected to the other end of the hydraulic cylinder I (31) and the hydraulic cylinder II (32) after merging. The second interface of the electromagnetic reversing valve II (44) is connected to one end of the hydraulic cylinder III (49) through the hydraulic control check valve III (45); the third interface of the electromagnetic reversing valve II (44) is connected to the check valve III (47) and the throttle valve II (48) through the hydraulic control check valve IV (46); the check valve III (47) and the throttle valve II (48) are connected to the second end of the hydraulic cylinder III (49) after merging; the hydraulic pump (39) is connected to the motor (40).

8. The corn harvester header profiling adjustment device according to claim 1, characterized in that: The control scheme of the header in the control system includes the following situations: 1) Lowering: When the left and right profiling devices detect that the height of the header on both sides is higher than the upper limit of the height threshold interval in the up-down direction, the hydraulic cylinders I and II are controlled to contract, so that the header height is lowered in the up-down direction until it stabilizes within the set height threshold interval; 2) Raising: When one of the left and right profiling devices detects that the height of the header is lower than the lower limit of the height threshold interval in the up-down direction, the hydraulic cylinders I and II are controlled to extend so that the header height is raised in the up-down direction until it stabilizes within the set up-down threshold interval; 3) No lifting: When the profiling devices on both sides detect that the height of the header on that side is within the height threshold range, the header is not adjusted up and down, and the hydraulic cylinders I and II are controlled to be stationary, and the header is not adjusted up and down; 4) Rotation: When the height detected by the profiling device on one side is greater than the height detected by the profiling device 1 on the other side, and the difference is greater than the rotation threshold, the hydraulic cylinder III is controlled to contract / extend, so that the cutting table rotates around the cutting table rotation point, the height on one side decreases, and the height on the other side increases; until the height difference between the two sides is stabilized within the set left and right direction range. 5) No rotation: When the height difference detected by the profiling devices on both sides is within the set rotation threshold, the left and right directions of the header are not adjusted.

9. The corn harvester header profiling adjustment device according to claim 8, characterized in that: Height detected by the profiling device R is the height of the center of the arc from the ground, L is the straight-line distance from the rotation center of the profiling plate to the center of the arc touching the ground, β is the measurement value of the angle sensor, β is regarded as the angle between the profiling plate and the line connecting the rotation center of the profiling plate and the rotation center of the bridge 5; α is the measurement value of the attitude sensor; It is the angle between the contour plate and the line connecting its rotation center and the center of the touchdown arc.

10. A corn harvester header profiling adjustment device according to claim 9, characterized in that: The information collected by the angle sensor is subjected to noise filtering by a profiling device noise correction Kalman recursive algorithm, and the profiling device noise correction Kalman recursive algorithm includes: A priori estimate: A priori estimated covariance: P t - =FP t-1 F T +Q (3-2) Update the Kalman gain: K t =P t - H T (HP t - H T +R) -1 (3-3) Revised Estimates: Update the posterior estimated covariance: P t =(I-K t H)P t - (3-5) Among them, F is the state transfer matrix, B is the control matrix, U t-1 is the process control variable, Q is the variance of process noise, which affects the accuracy of the predicted value, R is the variance of observation noise, which affects the accuracy of the observed value, H is the observation matrix, and is a constant; Zt is the observed variable with noise removed as the measurement value β of the angle sensor at this moment, K t is the Kalman gain.

Images