Method for adjusting position and posture of grabbing arm of reciprocating bale plucker through weighing sensor

Abstract

The invention discloses a method for adjusting the position and posture of a grabbing arm of a reciprocating bale plucker through a weighing sensor, and belongs to the technical field of bale pluckers. The method comprises the steps of initialization calibration, real-time acquisition, tension deviation calculation, deviation judgment, adjustment control and the like. Firstly, numerical values of weighing sensors at the two ends are read as preset reference values when the grabbing arm is in a horizontal posture, then actual working tension values at the two ends are collected in real time in the working process and compared with the preset reference values to obtain tension deviation, and finally the posture states of the two ends of the grabbing arm are judged according to the tension deviation. And the lifting motor on the corresponding side is controlled to adjust the retracting and releasing amount of the belt, so that the tension deviation approaches zero, and automatic adjustment and horizontal keeping of the posture of the grabbing arm are realized. According to the invention, the physical rule that the working tension at the two ends changes when the grabbing arm inclines is utilized, the pose deviation is converted into a detectable force signal, the deviation is eliminated through closed-loop feedback control, and the problem that the lifting motion of the large-width grabbing arm is unstable is solved.

Description

Technical Field

[0001] This invention belongs to the technical field of cotton grabbing machine, specifically relating to a method for adjusting the position and posture of the grabbing arm of a reciprocating cotton grabbing machine using a weighing sensor. Background Technology

[0002] The cotton cleaning and carding process is a crucial step in cotton fiber processing within the textile industry. The reciprocating cotton grabber, as the starting device in this process, directly impacts the technological parameters and product quality of all subsequent stages. With the textile industry's increasing demand for high output, manufacturers commonly increase the width of the grabber's arm to boost production, leading to continuous increases in arm length. As the core working component of the reciprocating cotton grabber, the grabber arm requires frequent lifting and lowering movements during operation to accommodate changes in cotton bale height.

[0003] As the gripper arm width increases, during lifting and lowering, the two ends in the width direction may experience asynchronous movement due to factors such as uneven load distribution, mechanical transmission errors, or external disturbances, causing the gripper arm to shake or tilt. When the gripper arm's position deviates from a horizontal state, the contact between the beater component at the bottom of the gripper arm and the cotton bale surface becomes uneven, resulting in inconsistent density and thickness of the gripped cotton fibers. This, in turn, affects the blending uniformity and process stability of the subsequent cleaning and carding process.

[0004] While existing technologies utilize load cells in cotton grabbers, these solutions primarily employ load cells to detect the weight of cotton in the weighing bin or for weighing control of quantitative output components. They fail to apply load cells to the detection and adjustment of the grabber's position and posture. Furthermore, current grabber lifting control methods typically employ single-motor or dual-motor synchronous drive schemes, preventing independent adjustment of the lifting motion at both ends and lacking effective automatic correction mechanisms when the grabber tilts.

[0005] Therefore, how to detect the position and orientation of the gripper in real time and make automatic adjustments so that the gripper always maintains a horizontal posture during operation has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the problems existing in the background art, the present invention provides a method for adjusting the position and posture of the gripper arm of a reciprocating cotton grabber using a weighing sensor, characterized by comprising the following steps:

[0007] S1. Initialization calibration: When the grab arm is in a horizontal position, read the values ​​of the load cells at both ends of the grab arm and use these values ​​as the preset reference values ​​of the working tension on both sides.

[0008] S2. Real-time acquisition: During the operation of the grab arm, the actual working tension values ​​on the left and right sides of the grab arm are acquired in real time through the weighing sensors installed at both ends of the grab arm.

[0009] S3. Tension deviation calculation: The actual working tension values ​​collected on both sides are compared with the preset reference values ​​on the corresponding sides to calculate the tension deviation on both sides.

[0010] S4. Deviation Judgment and Adjustment Control: Based on the sign and magnitude of the tension deviation, the attitude state of both ends of the grab arm is judged, and the lifting motor on the corresponding side is controlled to adjust the belt winding and unwinding, so that the tension deviation on both sides approaches zero, thereby realizing the automatic adjustment and horizontal maintenance of the grab arm position.

[0011] Furthermore, step S1 includes the following sub-steps:

[0012] S11. Install lifting motors at the left and right ends of the grab arm respectively. The two lifting motors are installed on the frame on the same side. Each lifting motor is connected to a winding shaft, and a winding wheel is installed on the winding shaft.

[0013] S12. Tie one end of the belt to the winding wheel. After the belt extends out, it passes over the fixed pulley from above, and then extends from below the fixed pulley to pass over the movable pulley. The movable pulley is fixed to the corresponding end above the grab arm.

[0014] S13. Connect the end of the belt extending past the movable pulley to the belt fixing component. Connect the load cell to the top of the belt fixing component and connect the load cell to the frame to complete the installation of the grab arm lifting mechanism.

[0015] S14. Adjust the position of the grab arm to make it completely horizontal with the ground. After the grab arm is completely stable, read the value of the left-side load cell as the preset reference value on the left side. Read the value from the weighing sensor on the right as the preset reference value on the right. .

[0016] Furthermore, step S2 includes the following sub-steps:

[0017] S21. When the grab arm is performing cotton-grabbing operations, the left-side weighing sensor detects and outputs the actual working tension value on the left side in real time. ;

[0018] S22, The right-side weighing sensor detects and outputs the actual working tensile force value on the right side in real time. ;

[0019] S23. The actual working tensile force value collected by the weighing sensors on both sides is transmitted to the control system in the form of an electrical signal for subsequent tensile force deviation calculation.

[0020] Furthermore, in step S3, the formula for calculating the tension deviation is:

[0021] ;

[0022] in, This indicates a deviation in tension on the left side. This represents the actual working tension value on the left side, detected in real time by the left-side weighing sensor. Set a preset reference value for the left side; This indicates a deviation in tension on the right side. The value of the actual working tension on the right side is detected in real time by the weighing sensor on the right side; Set a preset reference value for the right side.

[0023] Furthermore, step S4 includes the following sub-steps:

[0024] S41. Determine the deviation on the left side: when When the left end of the grab arm is tilted upwards, it is determined that the grab arm is tilted upwards; when At that time, it was determined that the left end of the grab arm had sunk.

[0025] S42. Determine the deviation on the right side: when When the right end of the grab arm is tilted upwards, it is determined that the grab arm is tilted upwards; when At that time, it was determined that the right end of the grab arm had sunk.

[0026] S43. Based on the judgment result, control the corresponding lifting motor to adjust it so that the tension deviation approaches zero, thereby adjusting the position of the grab arm to a horizontal state.

[0027] Furthermore, in step S43, a proportional control algorithm is used to calculate the adjustment control quantity of the lifting motor. The specific calculation formula is as follows:

[0028] ;

[0029] in, This represents the actual adjustment and control value of the left-side lifting motor; This represents the actual adjustment and control value of the right-side lifting motor; This is the proportionality coefficient; This indicates a deviation in tension on the left side. This represents the deviation of the tension on the right side.

[0030] Furthermore, the adjustment and control method in step S43 is as follows:

[0031] when When the left-side lifting motor drives the winding wheel to reverse, the belt lengthens, lowering the height of the left end of the grab arm; when At this time, control the left lifting motor to drive the winding wheel to rotate forward, so that the belt shortens and the height of the left end of the grab arm is raised;

[0032] when When the right-side lifting motor reverses, the belt lengthens, lowering the height of the right end of the grab arm; when At that time, control the right-side lifting motor to drive the winding wheel to rotate forward, so that the belt shortens and the right end of the grab arm is raised.

[0033] Furthermore, the proportionality coefficient Determined through the following calibration method:

[0034] S81. Intentionally tilt the grab arm at a preset angle and record the change in tension detected by the weighing sensors on both sides at this time;

[0035] S82. Control the lifting motor to adjust the belt winding and unwinding amount so that the grab arm returns to horizontal, and record the amount of lifting motor movement;

[0036] S83. Repeat steps S81 and S82 several times. Based on the tensile force changes and corresponding motor actions recorded in the multiple tests, calculate and determine the proportional coefficient. The value of .

[0037] Furthermore, in step S4, a periodic sampling and feedback adjustment method is used for control, specifically as follows:

[0038] According to the preset sampling period, steps S2 to S4 are executed periodically to acquire the tension data of the weighing sensors on both sides in real time, calculate the tension deviation and output the adjustment control quantity, so that the tension on both sides gradually approaches the corresponding preset reference value, thereby realizing the closed-loop automatic adjustment of the gripper arm position.

[0039] In a preferred embodiment, the bottom of the gripper arm is evenly arranged with a cotton pressing roller component, a beater component, and a gripper suction cavity. The middle part of the gripper arm has a hollow air duct structure, so that the center of gravity of the gripper arm is located in the lower middle part of the gripper arm. The belt is connected to the upper left and upper right corners of the gripper arm through movable pulleys.

[0040] The beneficial effects achieved by this invention are as follows:

[0041] This invention, by setting up an independent lifting motor at each end of the gripper arm, allows for independent control of the lifting movements of the left and right ends of the gripper arm, providing a hardware foundation for adjusting the gripper arm's posture. This dual-motor independent control layout breaks the limitations of traditional single-motor or dual-motor synchronous drive schemes, enabling differentiated adjustments at each end of the gripper arm based on their respective posture deviations, thereby achieving precise correction of the gripper arm's tilt state.

[0042] This invention places a weighing sensor between the belt fixing component and the frame, indirectly obtaining the working tension values ​​at both ends of the grab arm by detecting belt tension. Since the grab arm's center of mass is located in its lower middle position, when the grab arm tilts, the working tension at the tilted end increases while the working tension at the lowered end decreases. This invention utilizes this physical law to convert the difficult-to-measure positional deviation into an easily detectable force signal. By comparing the actual working tension value with a preset reference value to calculate the tension deviation, the tilting or lowering state of both ends of the grab arm and the degree of deviation can be accurately determined, providing a reliable decision-making basis for subsequent adjustment and control.

[0043] This invention employs a proportional control algorithm to calculate the adjustment control quantity of the lifting motor based on the tension deviation, and achieves closed-loop control through periodic sampling and feedback adjustment. The proportional control algorithm features fast response speed and simple implementation, enabling the tension deviation to quickly approach zero. Furthermore, by calibrating the proportional coefficient during the equipment installation and commissioning phase, the adjustment control process can be matched with the actual working conditions, ensuring the stability and accuracy of the adjustment effect.

[0044] The method provided by this invention enables the gripper arm to automatically adjust its position in real time during operation, maintaining a horizontal state without manual intervention, effectively solving the problem of unstable lifting and lowering motion of a wide gripper arm. By ensuring the horizontal posture of the gripper arm, the beater component makes uniform contact with the cotton bale surface, improving the uniformity and stability of cotton fiber gripping, thereby enhancing the process quality of subsequent cleaning and carding processes. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the grab arm lifting component.

[0046] Figure 2 This is a schematic diagram of the lifting components of a cotton grabber;

[0047] Figure 3 This is a schematic diagram of the gripper arm;

[0048] Figure 4 This is a schematic diagram of the force state when the grab arm is horizontal;

[0049] Figure 5 This is a schematic diagram of the force state when the grab arm is tilted. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] Reference Figures 1-5 This invention provides a method for adjusting the gripper arm posture of a reciprocating cotton grabber using a weighing sensor. This method is applied to the gripper arm lifting control system of a gantry-type reciprocating cotton grabber. The method involves the following device structure: a gripper arm lifting device for a reciprocating cotton grabber, mainly composed of a frame 1, a lifting motor 2, a winding shaft 3, a winding wheel 4, a belt 5, a fixed pulley 6, a belt fixing component 7, a weighing sensor 8, a movable pulley 9, and a gripper arm 10. The frame 1 serves as the supporting frame for the entire gripper arm lifting device, providing a mounting base for the lifting motor 2, the fixed pulley 6, and the weighing sensor 8. The frame 1 is typically constructed of welded steel, possessing sufficient rigidity and strength to withstand the dynamic loads generated during the lifting of the gripper arm 10.

[0052] The gripper arm 10 is the core working component of the reciprocating cotton grabber, extending along its width to grab cotton fibers from the surface of the cotton bale. A pressure roller component 101, a beater component 102, and a gripper suction chamber 103 are evenly arranged at the bottom of the gripper arm 10. The pressure roller component 101 compresses the cotton fibers on the surface of the cotton bale during the grabbing process, making it easier for the beater component 102 to peel the cotton fibers from the bale. The beater component 102 typically consists of a high-speed rotating beater roller and its metal rack, using centrifugal force and cutting force generated by high-speed rotation to tear the cotton fibers from the surface of the cotton bale. The gripper suction chamber 103 is located above the beater component 102, creating a negative pressure environment inside to suck in the cotton fibers peeled by the beater component 102 and transport them to the subsequent cleaning and carding process. The middle part of the gripper arm 10 has a hollow air duct structure, which is connected to the gripper suction chamber 103 and is used to guide airflow and transport cotton fibers. Since the working mechanisms such as the cotton pressing roller component 101, the beater component 102, and the gripper suction cavity 103 are concentrated at the bottom of the gripper arm 10, and the air duct structure in the middle is hollow, the center of gravity of the gripper arm 10 is located in the lower middle part of the gripper arm 10. This structural feature is of great significance for subsequent analysis of the change law of the working tension at both ends when the gripper arm 10 is tilted.

[0053] The lifting motor 2 drives the gripper arm 10 to perform lifting and lowering movements. In this invention, one lifting motor 2 is installed at each of the left and right ends of the gripper arm 10, for a total of two lifting motors 2, each mounted on the same side of the frame 1. The two lifting motors 2 operate independently, each controlling the lifting and lowering movements of the left and right ends of the gripper arm 10. This dual-motor independent control layout is the hardware basis for achieving the position and posture adjustment of the gripper arm 10. Each lifting motor 2's output end is connected to a winding shaft 3, which extends horizontally and is supported on the frame 1 by bearings. A winding wheel 4 is coaxially mounted on the winding shaft 3, rotating synchronously with the winding shaft 3. When the lifting motor 2 rotates forward, the winding wheel 4 tightens the belt 5; when the lifting motor 2 rotates in reverse, the winding wheel 4 releases the belt 5, allowing it to lengthen.

[0054] The belt 5 is a flexible transmission element connecting the lifting motor 2 and the grab arm 10, used to convert the rotational motion of the lifting motor 2 into the linear lifting motion of the grab arm 10. One end of the belt 5 is wound around the winding pulley 4, and the other end extends from the winding pulley 4, first passing over the fixed pulley 6 from above, then extending from below the fixed pulley 6 and passing over the movable pulley 9. Finally, the end of the belt 5 extending from the movable pulley 9 is connected to the belt fixing component 7. The fixed pulley 6 is fixedly installed on the frame 1, and its position does not change with the lifting of the grab arm 10, mainly serving to change the direction of the belt 5. The movable pulley 9 is fixedly installed at the corresponding end above the grab arm 10, and it rises and falls synchronously with the grab arm 10. Through the cooperation of the fixed pulley 6 and the movable pulley 9, a pulley block structure is formed, which can reduce the driving torque required by the lifting motor 2 to a certain extent, and at the same time make the direction of the belt 5 more reasonable. The belt 5 is connected to the upper left and upper right corners of the grab arm 10 via the movable pulley 9. The tension of the belt 5 on the grab arm 10 is applied at both ends of the upper part of the grab arm 10.

[0055] The belt fixing component 7 is used to fix the end of the belt 5 and also serves as a transitional component connecting the load cell 8 and the belt 5. The load cell 8 is connected to the top of the belt fixing component 7, and the other end of the load cell 8 is fixedly connected to the frame 1. Through the above connection method, the tension generated by the belt 5 on the gripper arm 10 is transmitted to the load cell 8 via the belt fixing component 7. The load cell 8 can detect the tension on the belt 5 in real time, that is, the working tension at the corresponding end of the gripper arm 10. The load cell 8 is a sensor that converts force signals into electrical signals. Its core component is usually a resistance strain gauge. When subjected to external force, the strain gauge deforms, causing a change in resistance value. The change in resistance is converted into a voltage signal output through a Wheatstone bridge circuit. In this invention, one load cell 8 is set at each of the left and right ends of the gripper arm 10, for a total of two load cells 8. These two load cells can detect the working tension values ​​at the left and right ends of the gripper arm 10 in real time and transmit the detection results to the control system in the form of electrical signals.

[0056] When the grab arm 10 is stationary or in a uniform lifting state, the grab arm 10 is in a state of force equilibrium. At this time, the sum of the working tensions generated by the belts 5 at both ends of the grab arm 10 is equal to the weight of the grab arm 10 itself. Since the center of mass of the grab arm 10 is fixed, and the connection position between the belts 5 and the grab arm 10 is also fixed, under static equilibrium conditions, the value of the working tension at both ends of the grab arm 10 is only related to the horizontal distance of the center of mass relative to the connection points of the belts on both sides. When the grab arm 10 maintains a horizontal posture, the horizontal distance of the center of mass relative to the connection points of the belts on both sides is a definite value, and the corresponding working tension at both ends is also definite. When the grab arm 10 tilts, the horizontal distance of the center of mass relative to the connection points of the belts on both sides will change, thus causing a change in the working tension at both ends. Since the center of mass of the grab arm 10 is located in the lower middle position, when one end of the grab arm 10 tilts upward, the horizontal distance of the belt connection point at that end relative to the center of mass decreases. According to the principle of torque balance, the working tension at that end will increase; correspondingly, the working tension at the lower end will decrease. The aforementioned physical laws are the theoretical basis for this invention to detect and adjust the positional deviation of the gripper arm 10 using the weighing sensor 8.

[0057] Based on the above-described device structure, the method for adjusting the gripper arm posture of a reciprocating cotton grabber using a weighing sensor provided by the present invention includes the following steps.

[0058] Step S1: Initialization Calibration; This step is performed after the initial installation or maintenance of the cotton grabber, and is used to obtain the preset reference values ​​of the working tension at both ends when the grabber arm 10 is in an ideal horizontal position. Step S1 specifically includes the following sub-steps.

[0059] Step S11: Install lifting motors 2; Install one lifting motor 2 at each of the left and right ends of the grab arm 10, and fix the two lifting motors 2 on the same side of the frame 1. The output shaft of each lifting motor 2 is connected to a winding shaft 3, which is mounted on the frame 1 through a bearing seat and can rotate freely along its axis. A winding wheel 4 is coaxially mounted on each winding shaft 3. The winding wheel 4 is fixed to the winding shaft 3 by a key connection or integral molding to ensure that the winding wheel 4 and the winding shaft 3 rotate synchronously.

[0060] Step S12: Install belt 5 and pulley block; wind one end of belt 5 onto winding wheel 4 and secure it firmly. After extending from winding wheel 4, belt 5 first passes over fixed pulley 6, which is fixedly installed on frame 1, from above. Then, belt 5 extends downward from below fixed pulley 6 and passes over movable pulley 9, which is pre-fixed at the corresponding end above grab arm 10. Both fixed pulley 6 and movable pulley 9 are supported by rolling bearings to reduce frictional resistance during belt 5 operation.

[0061] Step S13: Install the load cell 8; connect the belt 5 to the belt fixing component 7 via the extended end of the pulley 9. A reliable connection between the belt 5 and the belt fixing component 7 can be achieved by bolting or clamping. The load-bearing end of the load cell 8 is bolted to the top of the belt fixing component 7, and the fixed end of the load cell 8 is connected to the frame 1. Through the above installation steps, the installation of the mechanical transmission components and detection elements in the grab arm lifting mechanism is completed.

[0062] Step S14: Calibrate the preset reference value; adjust the position of the grab arm 10 so that its lower end face is completely parallel to the ground, i.e., the grab arm 10 is in a horizontal position. A level or laser rangefinder can be used to assist in adjusting the horizontality of the grab arm 10. After the position of the grab arm 10 is adjusted and completely stable, i.e., the grab arm 10 no longer shakes or shifts, read the value output by the left-side weighing sensor 8 and record it as the left-side preset reference value. Simultaneously, it reads the value output by the weighing sensor 8 on the right and records it as the preset reference value on the right. Left-side preset reference value and the preset reference value on the right These two values ​​represent the working tension values ​​that the grab arm 10 should bear at both ends when it is in an ideal horizontal position. These two values ​​will serve as the benchmark for judging whether the position of the grab arm 10 has deviated during subsequent control. Through the initial calibration in step S1, the system obtains a reference benchmark for position judgment, providing a basis for subsequent real-time adjustment and control.

[0063] Step S2: Real-time data acquisition; this step is performed continuously during the normal operation of the gripper arm 10 to obtain the actual working tension values ​​at both ends of the gripper arm 10. Step S2 specifically includes the following sub-steps.

[0064] Step S21: Collect the actual working tension on the left side; When the grab arm 10 is performing the cotton grabbing operation, the left-side weighing sensor 8 continuously detects the tension on the left-side belt 5 and converts the detection result into an electrical signal output. After being amplified and filtered by the signal conditioning circuit, this electrical signal is input to the analog-to-digital converter module of the control system, converted into a digital quantity, and used as the actual working tension value on the left side. It is stored in the data register of the control system.

[0065] Step S22: Collect the actual working tension on the right side; the right-side load cell 8 continuously detects the tension on the right-side belt 5 in the same way as the left-side load cell 8, and outputs the corresponding electrical signal. This electrical signal, after signal conditioning and analog-to-digital conversion, is used as the actual working tension value on the right side. It is stored in the data register of the control system.

[0066] Step S23: Data transmission; The actual working tensile force values ​​collected by the two weighing sensors 8 are transmitted to the control system in the form of electrical signals via signal cables. The control system can be implemented using a programmable logic controller or an industrial computer, etc. The collected actual working tensile force value on the left side... And the actual working tensile force value on the right This will be used for the tension deviation calculation in the subsequent step S3. Through the real-time acquisition in step S2, the control system can continuously obtain the working tension information at both ends of the grab arm 10 at the current moment, providing real-time data support for judging the position and orientation of the grab arm 10.

[0067] Step S3: Tension Deviation Calculation Step; This step compares the actual working tension value collected in Step S2 with the preset reference value calibrated in Step S1 to calculate the tension deviation on both sides. The control system calculates the actual working tension value on the left side. Compared with the preset reference value on the left Perform the difference calculation to obtain the tension deviation on the left side. At the same time, the actual working tensile force value on the right side will be... Compared with the preset reference value on the right Perform the difference calculation to obtain the tension deviation on the right side. The formula for calculating tensile force deviation is:

[0068] ;

[0069] in, This represents the deviation of the tension on the left side, in N. The value of the actual working tension on the left side is detected in real time by the left-side weighing sensor 8, in N; The left-side preset reference value calibrated in step S14 is in N; This represents the right-side tension deviation, expressed in N. The value of the actual working tension on the right side is detected in real time by the weighing sensor 8 on the right side, in N; The right-side preset reference value calibrated in step S14 is in N.

[0070] Tension deviation and The sign of the deviation reflects the direction of the positional offset of the corresponding end of the grab arm 10 relative to the horizontal orientation. According to the aforementioned mechanical analysis, when one end of the grab arm 10 tilts upwards, the working tension at that end will be greater than the preset reference value, and the corresponding tension deviation is positive; when one end of the grab arm 10 tilts downwards, the working tension at that end will be less than the preset reference value, and the corresponding tension deviation is negative. Therefore, by analyzing the sign of the tension deviation, the attitude state of both ends of the grab arm 10 can be determined. Simultaneously, the absolute value of the tension deviation reflects the degree to which the grab arm 10 deviates from the horizontal orientation; the larger the absolute value of the deviation, the more severe the tilt of the grab arm 10. Through the tension deviation calculation in step S3, the force signal detected by the weighing sensor 8 is converted into deviation information characterizing the attitude state of the grab arm 10, providing a quantitative basis for subsequent adjustment and control decisions.

[0071] Step S4: Deviation Judgment and Adjustment Control Step; This step judges the position and orientation of the grab arm 10 based on the tension deviation calculated in Step S3, and controls the corresponding lifting motor 2 to retract and extend the belt 5, so that the tension deviation approaches zero, thereby realizing the automatic adjustment and horizontal maintenance of the grab arm 10's position and orientation. Step S4 specifically includes the following sub-steps.

[0072] Step S41: Determine the deviation on the left side; the control system reads the tension deviation on the left side. The value is calculated and its sign is determined. When A value greater than 0 indicates the actual working tension value on the left side. Greater than the preset reference value on the left Based on the principles of mechanical analysis, it is determined that the left end of the grab arm 10 is in an upward-curving state, requiring the left-side lifting motor 2 to extend the belt 5 to lower the height of the left end. When it is less than 0, it indicates the actual working tension value on the left side. Less than the preset reference value on the left If the left end of the grab arm 10 is determined to be in a sunken state, it is necessary to control the left lifting motor 2 to shorten the belt 5 to raise the height of the left end.

[0073] Step S42: Determine the deviation on the right side; the control system uses the same logic as in step S41 to determine the tension deviation on the right side. Make a judgment. When When the value is greater than 0, the right end of the grab arm 10 is determined to be in an upward-curving state; when... When the value is less than 0, it is determined that the right end of the grab arm 10 is in a sunken state.

[0074] Step S43: Adjust and control according to the judgment result; This invention uses a proportional control algorithm to calculate the adjustment control quantity of the lifting motor 2. The proportional control algorithm is a basic and practical control strategy in the field of automatic control. Its characteristics are that the control quantity is proportional to the deviation, with fast response speed and simple implementation. The formula for calculating the adjustment control quantity is:

[0075] ;

[0076] in, The actual adjustment control value of the left-side lifting motor 2 is in mm; The actual adjustment control value of the right-side lifting motor 2 is in mm; This is a proportionality coefficient, with units of mm / N; This represents the deviation of the tension on the left side, in N. This represents the deviation of the tension on the right side, in N.

[0077] proportionality coefficient It is a pre-set empirical parameter used to characterize the amount of motor belt adjustment corresponding to a unit tension deviation. Proportional coefficient. The value of the proportional coefficient needs to be determined based on the specific model and operating conditions of the cotton grabber. Factors such as the weight of the grabber arm 10, the stiffness of the belt 5, and the reduction ratio of the transmission mechanism will affect the proportional coefficient. The optimal value of the proportionality coefficient. The calibration method includes the following sub-steps. Step S81 involves intentionally tilting the grab arm 10 by a preset angle. This preset angle can be selected based on the possible tilt range under actual working conditions, and the change in tension detected by the two weighing sensors 8 is recorded at this time. Step S82 involves controlling the lifting motor 2 to adjust the winding and unwinding of the belt 5, so that the grab arm 10 returns from the tilted state to the horizontal state. At the same time, the action of the lifting motor 2 is recorded. This action can be characterized by the pulse count of the motor encoder or the displacement of the belt 5. Step S83 involves repeating steps S81 and S82 several times, preferably no less than 5 times, to obtain statistically significant test data. Based on the tension change values ​​and corresponding motor action data recorded from multiple tests, the proportional coefficient is calculated and determined using the least squares method or the average value method. The value of . The proportionality coefficient obtained through the above calibration method. Matching the actual operating conditions can make the adjustment and control process more stable and accurate.

[0078] Adjustment control quantity and The sign of the value determines the rotation direction of the corresponding lifting motor 2. When When the value is greater than 0, the left lifting motor 2 drives the winding wheel 4 to reverse, causing the belt 5 to lengthen, thereby lowering the height of the left end of the grab arm 10 and eliminating the upward tilt of the left end. When When the value is less than 0, the left lifting motor 2 drives the winding wheel 4 to rotate forward, shortening the belt 5 and raising the height of the left end of the grab arm 10, eliminating the sinking state of the left end. When the value is greater than 0, the right-side lifting motor 2 drives the winding wheel 4 to reverse, causing the belt 5 to lengthen. When the value is less than 0, control the right-side lifting motor 2 to drive the winding wheel 4 to rotate forward, causing the belt 5 to shorten.

[0079] In step S4, a periodic sampling and feedback adjustment method is used for control. The control system periodically executes steps S2 to S4 according to a preset sampling period, continuously collecting the actual working tension values ​​of the weighing sensors 8 on both sides, calculating the tension deviation, and outputting the corresponding adjustment control quantity. The selection of the sampling period needs to comprehensively consider the computing power of the control system and the speed characteristics of the lifting and lowering motion of the grab arm 10. An excessively long sampling period will lead to a delayed adjustment response, while an excessively short sampling period will increase the computational burden on the control system. The preferred sampling period is within the range of 10ms to 100ms. Through periodic sampling and feedback adjustment, the tension deviation on both sides will gradually approach zero, the actual working tension on both sides will gradually approach the corresponding preset reference value, and the posture of the grab arm 10 will gradually return to a horizontal state, thereby achieving closed-loop automatic adjustment of the grab arm 10's posture.

[0080] The method provided by this invention applies a weighing sensor 8 to the position detection and adjustment control of the gripper arm 10. By monitoring the working tension at both ends of the gripper arm 10 in real time and comparing it with a preset reference value, position deviations of the gripper arm 10 can be detected in a timely manner. Using a dual-motor independent control method, the left and right ends of the gripper arm 10 can be adjusted separately, ensuring that the gripper arm 10 maintains a horizontal posture throughout the operation. This adjustment method fully utilizes the physical laws governing the change in working tension at both ends when the gripper arm 10 is tilted, converting position deviations into detectable force signals. These deviations are then eliminated through closed-loop feedback control, and the entire adjustment process is completed automatically without manual intervention. For gripper arms 10 with a large width, due to the greater distance between their ends and their heavier weight, instability such as shaking or tilting is more likely to occur during lifting and lowering movements. The method provided by this invention can effectively suppress these instabilities, ensuring that the gripper arm 10 maintains stable operation under various working conditions, thereby guaranteeing the uniformity and stability of cotton-grabbing operations and improving the process quality of subsequent cleaning and carding processes.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for adjusting the position and posture of the gripper arm of a reciprocating cotton grabber using a weighing sensor, characterized in that, Includes the following steps: S1. Initialization calibration: When the grab arm is in a horizontal position, read the values ​​of the load cells at both ends of the grab arm and use these values ​​as the preset reference values ​​of the working tension on both sides. S2. Real-time acquisition: During the operation of the grab arm, the actual working tension values ​​on the left and right sides of the grab arm are acquired in real time through the weighing sensors installed at both ends of the grab arm. S3. Tension deviation calculation: The actual working tension values ​​collected on both sides are compared with the preset reference values ​​on the corresponding sides to calculate the tension deviation on both sides. S4. Deviation Judgment and Adjustment Control: Based on the sign and magnitude of the tension deviation, the attitude state of both ends of the grab arm is judged, and the lifting motor on the corresponding side is controlled to adjust the belt winding and unwinding, so that the tension deviation on both sides approaches zero, thereby realizing the automatic adjustment and horizontal maintenance of the grab arm position.

2. The method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 1, characterized in that, Step S1 includes the following sub-steps: S11. Install lifting motors at the left and right ends of the grab arm respectively. The two lifting motors are installed on the frame on the same side. Each lifting motor is connected to a winding shaft, and a winding wheel is installed on the winding shaft. S12. Tie one end of the belt to the winding wheel. After the belt extends out, it passes over the fixed pulley from above, and then extends from below the fixed pulley to pass over the movable pulley. The movable pulley is fixed to the corresponding end above the grab arm. S13. Connect the end of the belt extending past the movable pulley to the belt fixing component. Connect the load cell to the top of the belt fixing component and connect the load cell to the frame to complete the installation of the grab arm lifting mechanism. S14. Adjust the position of the grab arm to make it completely horizontal with the ground. After the grab arm is completely stable, read the value of the left-side load cell as the preset reference value on the left side. Read the value from the weighing sensor on the right as the preset reference value on the right. .

3. The method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 1, characterized in that, Step S2 includes the following sub-steps: S21. When the grab arm is performing cotton-grabbing operations, the left-side weighing sensor detects and outputs the actual working tension value on the left side in real time. ; S22, The right-side weighing sensor detects and outputs the actual working tensile force value on the right side in real time. ; S23. The actual working tensile force value collected by the weighing sensors on both sides is transmitted to the control system in the form of an electrical signal for subsequent tensile force deviation calculation.

4. The method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 1, characterized in that, In step S3, the formula for calculating the tension deviation is: ； in, This indicates a deviation in tension on the left side. This represents the actual working tension value on the left side, detected in real time by the left-side weighing sensor. Set a preset reference value for the left side; This indicates a deviation in tension on the right side. The value of the actual working tension on the right side is detected in real time by the weighing sensor on the right side; Set a preset reference value for the right side.

5. A method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 4, characterized in that, Step S4 includes the following sub-steps: S41. Deviance judgment on the left side: when When the left end of the grab arm is tilted upwards, it is determined that the grab arm is tilted upwards; when At that time, it was determined that the left end of the grab arm had sunk. S42. Determine the deviation on the right side: when When the right end of the grab arm is tilted upwards, it is determined that the grab arm is tilted upwards; when At that time, it was determined that the right end of the grab arm had sunk. S43. Based on the judgment result, control the corresponding lifting motor to adjust it so that the tension deviation approaches zero, thereby adjusting the position of the grab arm to a horizontal state.

6. A method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 5, characterized in that, In step S43, a proportional control algorithm is used to calculate the adjustment control quantity of the lifting motor. The specific calculation formula is as follows: ； in, This represents the actual adjustment and control value of the left-side lifting motor; This represents the actual adjustment and control value of the right-side lifting motor; This is the proportionality coefficient; This indicates a deviation in tension on the left side. This represents the deviation of the tension on the right side.

7. A method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 6, characterized in that, The adjustment and control method in step S43 is as follows: when When the left-side lifting motor drives the winding wheel to reverse, the belt lengthens, lowering the height of the left end of the grab arm; when At this time, control the left lifting motor to drive the winding wheel to rotate forward, so that the belt shortens and the height of the left end of the grab arm is raised; when When the right-side lifting motor reverses, the belt lengthens, lowering the height of the right end of the grab arm; when At that time, control the right-side lifting motor to drive the winding wheel to rotate forward, so that the belt shortens and the right end of the grab arm is raised.

8. A method for adjusting the position and posture of a reciprocating cotton grabber arm using a weighing sensor according to claim 6, characterized in that, The proportionality coefficient Determined through the following calibration method: S81. Intentionally tilt the grab arm at a preset angle and record the change in tension detected by the weighing sensors on both sides at this time; S82. Control the lifting motor to adjust the belt winding and unwinding amount so that the grab arm returns to horizontal, and record the amount of lifting motor movement; S83. Repeat steps S81 and S82 several times. Based on the tensile force changes and corresponding motor actions recorded in the multiple tests, calculate and determine the proportional coefficient. The value of .

9. A method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 1, characterized in that, Step S4 employs a periodic sampling and feedback adjustment method for control, specifically as follows: According to the preset sampling period, steps S2 to S4 are executed periodically to acquire the tension data of the weighing sensors on both sides in real time, calculate the tension deviation and output the adjustment control quantity, so that the tension on both sides gradually approaches the corresponding preset reference value, thereby realizing the closed-loop automatic adjustment of the gripper arm position.

10. A method for adjusting the position of the gripper arm of a reciprocating cotton grabber using a weighing sensor according to claim 1, characterized in that, The bottom of the gripper arm is evenly arranged with cotton pressing roller components, beater components and gripper suction chamber. The middle part of the gripper arm is a hollow air duct structure, so that the center of gravity of the gripper arm is located in the lower middle part of the gripper arm. The belt is connected to the upper left and upper right corners of the gripper arm through movable pulleys respectively.

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