Pressure-diameter coordinated regulation and control system and method for seed cotton circular die packer
Through the coordinated control system of the state perception module and the decision control module, the pressure and diameter of the seed cotton round mold baler are controlled in a coordinated manner, which solves the problem of uneven forming quality and improves control accuracy and forming quality.
Patent Information
- Application Number
- CN202511804862.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-02-27
AI Technical Summary
Existing technologies make it difficult to achieve coordinated control of pressure and diameter during the seed cotton circular mold forming process, resulting in uneven forming quality.
The cotton mold state parameters are collected in real time by a state perception module. The decision control module switches between density-priority and diameter-priority control modes. Combined with a multivariable control algorithm and a rocker arm servo drive mechanism, the cotton mold pressing force and diameter are coordinated and controlled.
It improves the uniformity and consistency of cotton mold forming quality, adapts to changes in physical properties during seed cotton compression, and enhances control precision.
Smart Images
Figure CN121572640A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of agricultural machinery automation, specifically to a circular mold baler for post-harvest processing of seed cotton, and more particularly to a pressure-diameter coordinated control system and method for a seed cotton circular mold baler. Background Technology
[0002] Cylindrical baling is a crucial step in the post-harvest processing of machine-picked seed cotton. Its core lies in transforming initially loose seed cotton into a stable, regularly shaped cylindrical baler through compression and winding processes. High-quality balers are essential for ensuring the economy and safety of subsequent transportation and storage. During the baler formation process, seed cotton, as a typical viscoelastic biomass material, exhibits significant nonlinear mechanical behavior. The final quality of the baler primarily depends on two core physical quantities: internal density and outer diameter. These two parameters are physically closely coupled: changes in compressive strength directly affect the degree of compression of the cotton layer and the diameter increase during subsequent winding; conversely, constraints on the diameter directly affect the distribution of internal pressure and relaxation behavior. Therefore, achieving coordinated control of these two strongly coupled parameters throughout the entire forming cycle is a key technical challenge for achieving high-quality baling and a technical problem worthy of in-depth research in this field. Summary of the Invention
[0003] This invention proposes a pressure-diameter coordinated control system and method for a seed cotton circular mold baler, which is used to achieve coordinated control of the cotton mold pressing force and diameter to improve the uniformity and consistency of the molding quality.
[0004] In a first aspect, the present invention provides a pressure-diameter coordinated control system for a seed cotton circular die baler, characterized in that it comprises: The state sensing module is configured to collect state parameters during the cotton mold forming process in real time, and it is equipped with features for indirectly detecting the compressive strength of the cotton mold. P a Torque sensor and for detecting cotton mold diameter D a Angle encoder; The decision control module, which is signal-connected to the state perception module, is configured as follows: (1) Identify the forming stage based on the state parameters and switch between density priority control mode and diameter priority control mode; (2) In the density priority control mode, the target pressure is set according to the preset rules. P s And using preset functional relationships D s =f( P s Calculate the corresponding target diameterD s ; (3) In the diameter priority control mode, the target diameter is set as a constant value, and the feedback signal of the cotton die compaction force is received to monitor the change in real time. D s P a (4) The decision control module further comprises a cooperative controller for generating a control instruction for driving the rocker servo driving mechanism through a multivariable control algorithm based on the deviation between the target value ( P s , D s ) and the actual value ( P a , D a ).
[0005] The execution driving module, which is in signal connection with the decision control module, comprises a rocker servo driving mechanism for cooperatively adjusting the diameter and compaction force of the cotton die according to the control instruction.
[0006] Preferably, the function relationship D s = f( Ps ) is represented as a linear function: D s = D min + k × ( P s - P min ) wherein, D min is a preset minimum diameter, P min is a preset minimum compaction force, k is a proportional coefficient.
[0007] Preferably, the switching condition of the density priority control mode and the diameter priority control mode is that the diameter of the cotton die D a reaches a preset first target diameter value D 1 .
[0008] Preferably, the multivariable control algorithm comprises a fuzzy PID control, a decoupling control or a model predictive control.
[0009] Preferably, the decision control module is configured to: in the diameter priority control mode, when the cotton module compacting force P a is lower than a preset threshold, determining that the cotton module compacting force P a has stabilized.
[0010] In a second aspect, the application further provides a pressure-diameter coordinated control method for a seed cotton bale former, applied to the system described above, comprising the following steps: Step S1: initial winding, controlling the rocker servo mechanism to move to an initial position and applying a constant initial torque T 0 , so that the initial compacting force is P 0 , to enable the seed cotton to be stably wound to form an initial cotton core; Step S2: density ramping and diameter coordinated growth, entering the density priority control mode, controlling the target compacting force P s to increase at a preset rate over time, and simultaneously using the preset function relationship D s = f( P s ) to calculate the target diameter D s in real time, and through multivariable closed-loop control, the cotton module compacting force P a and the cotton module diameter D a respectively track the target compacting force P s and the target diameter D s ; Step S3: diameter maintenance and pressure relaxation, when the cotton module diameter D a reaches the first set diameter D 1 , switching to the diameter priority control mode, locking the target diameter D s as the first set diameter D 1 , controlling the rocker servo mechanism to maintain the first set diameter D 1 constant, and monitoring the relaxation process of the cotton module compacting force P a until it is determined to be stable when the change rate is lower than a preset threshold; Step S4: final sizing, when the cotton module compacting force Pa After stabilization, control the rocker arm servo mechanism to adjust the diameter of the cotton mold. D a Adjust to the second target diameter D 2 and maintain the preset time. t Apply pressure and shape to complete the final shaping of the cotton mold.
[0011] Compared with the prior art, the beneficial effects of the present invention are: The multivariable control algorithm achieves coordinated control of pressure and diameter, solving the problem of uneven molding quality caused by independent parameter control. The dual-mode switching strategy adapts to changes in physical properties during the cotton compression process, thereby improving control precision. Attached Figure Description
[0012] Figure 1 This is a block diagram of the collaborative control system structure provided in the embodiments of the present invention; Figure 2 This is a schematic diagram of the collaborative regulation method provided in the embodiments of the present invention; Figure 3 This is a schematic diagram showing the parameter variation trend throughout the entire cotton mold forming cycle provided in this embodiment of the invention. Detailed Implementation
[0013] The following will refer to the appendices in the embodiments of the present invention. Figures 1-3 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0014] Example 1: As Figure 1 As shown, the present invention provides a pressure-diameter coordinated control system for a seed cotton circular die baler, characterized in that it includes: The state sensing module is used to collect state parameters in real time during the cotton mold forming process, including: (1) A torque sensor, installed on the drive shaft of the rocker arm of the baling machine, is used to detect the output torque of the drive shaft, which indirectly characterizes the compressive force of the baling belt on the cotton. P a ; (2) An angle encoder, installed at the rotation center of the rocker arm, is used to measure the real-time rotation angle of the rocker arm and calculate the current diameter of the cotton mold based on the angle and the system geometry.
[0015] A decision control module is in signal connection with the state perception module, and comprises a control unit which can be an embedded controller (MCU / DSP / ARM), a programmable logic controller (PLC), an industrial computer (IPC) or a cloud-based control system, and a multi-stage cooperative control program is stored in the control unit and configured to perform the following operations: (1) calculating the cotton block diameter according to the signal of the angle encoder D a ; calculating the cotton block compaction force according to the signal of the torque sensor and through a calibration relationship P a ; (2) judging the current forming stage according to a preset forming stage division strategy based on the diameter cotton block D a and the cotton block compaction force P a ; (3) switching between a density priority control mode and a diameter priority control mode according to the current forming stage; (4) in the density priority control mode, increasing a target compaction force P s by using a preset ramp function, and dynamically calculating a target diameter D s =f( P s ) based on a preset function relationship D s。
[0016] In specific implementation, in the diameter priority control mode, the target diameter set value is locked D s , and a relaxation process of the cotton block compaction force P a is monitored.
[0017] In specific implementation, based on the deviation of the target compaction force P s , the target diameter D s , the cotton block compaction force P a , and the cotton block diameter D a , a control instruction for an execution driving module is calculated through a multivariable control algorithm.
[0018] An execution driving module is in signal connection with the decision control module, and is used for receiving the control instruction and driving corresponding mechanisms of the baling press to act, and comprises: The rocker servo driver and rocker servo motor are used to drive the rocker movement, accurately control the output torque and position.
[0019] In addition, as Figure 2 shown, the application provides a pressure-diameter coordinated control method for the seed cotton round module baler applied to the above system, comprising the following steps: Step S1: initial winding, control the rocker servo mechanism to move to the initial position and apply a constant initial torque T 0 , so that the initial compaction force is P 0 , so that the seed cotton is stably wound to form an initial cotton core; Step S2: density ramping and diameter coordinated growth, enter the density priority control mode, control the target compaction force P s increases with time at a preset rate, and simultaneously uses the preset function relationship D s =f( P s ) to calculate the target diameter in real time D s , and through multivariable closed-loop control, the cotton module compaction force P a and the cotton module diameter D a respectively track the target compaction force P s and the target diameter D s ; Step S3: diameter maintenance and pressure relaxation, when the cotton module diameter D a reaches the first set diameter D 1 , switch to the diameter priority control mode, lock the target diameter D s as the first set diameter D 1 , control the rocker servo mechanism to maintain the first set diameter D 1 constant, and monitor the relaxation process of the cotton module compaction force P a , until its change rate is lower than the preset threshold value to determine that it tends to be stable; Step S4: final setting, after the cotton module compaction force P a is stable, control the rocker servo mechanism to set the cotton module diameter D aadjust to the second target diameter D 2 and keep for a preset time t The pressure is maintained for shaping, and the final shaping of the cotton module is completed.
[0020] One specific application of the embodiment is: The pressure-diameter coordinated control system of the ginned cotton round module baler of the embodiment includes a state sensing module, a decision control module, and an execution driving module. The torque sensor and the angle encoder in the state sensing module transmit real-time signals to the embedded controller in the decision control module.
[0021] The pressure-diameter coordinated control method of the ginned cotton round module baler of the embodiment is: After the program is initialized, the controller enters an initial winding phase, controls the rocker servo motor to rotate at a constant initial torque T 0 , and forms a cotton core, so that the initial compaction force is P 0 .
[0022] After entering the density ramping and diameter coordinated growth phase, the control unit starts the density ramping program. The target compaction force P s is set according to a preset rule, and the corresponding target diameter D s is calculated using a preset function relationship P s . D s ; In one preferred embodiment of the embodiment, the function relationship D s =f( P s ) can adopt a linear function: D s = D min + k × ( P s - P min ) wherein, D min is a preset minimum diameter, P min is a preset minimum compaction force, k and is a proportional coefficient.
[0023] It should be noted that the present application is not limited to a linear relationship. According to the moisture content, variety, and rebound characteristics of the ginned cotton, the function relationshipD s = f( P s ) can also be expressed as: an exponential function relationship, used to simulate the nonlinear hardening characteristics of seed cotton in the later compression stage; a piecewise function or a look-up table method, based on the best fitting curve of experimental data; adaptive dynamic mapping, i.e. correcting the parameters of f( P s ) according to the real-time detected density change rate of the cotton die during the forming process.
[0024] As long as the multivariable control means adopted based on the "dual-mode switching" strategy proposed in the present application, are covered within the protection scope of the present application.
[0025] In one preferred scheme of the present embodiment, the multivariable control algorithm adopts fuzzy PID control, and the controller adjusts through a comprehensive error signal e ( k ), which is formed by the weighted fusion of the compaction force error and the diameter error: u ( k ) = Kp x e ( k ) + Ki x Σe ( j ) + Kd x [ e ( k ) -e ( k-1 )] wherein, u(k) is the current time control output, e ( k ) = w 1 × ( P s -P a ) + w 2 × ( D s -D a ) is the comprehensive error, w 1 , w2 is the weight coefficient, K p , K i , K dAs a fuzzy adaptive parameter, it can be fuzzily adaptively adjusted according to the comprehensive error and its rate of change, thereby achieving coordinated control of the two variables of pressure force and diameter.
[0026] The fuzzy PID controller described above is characterized by: The comprehensive error calculation includes the pressure force error ( P s - P a ) and diameter error ( D s - D a Through weighting coefficients w 1 , w2 Fusion into a single comprehensive error e ( k This solved the coupling problem in multivariable control; Parameter adaptation: K p , K i , K d The three parameters are based on the error e ( k ) and error change rate Δ e ( k Real-time adjustments, with adjustment rules based on fuzzy reasoning: When | e ( k When the value is large, increase it. K p , reduce K d Quickly eliminate errors; When | e ( k When the value is small, decrease it. K p Increase K i , K d Improve stability; The specific adjustments are implemented through membership functions and fuzzy rule bases; Weighting: w 1 > w 2 The control strategy prioritizes density and places greater emphasis on the tracking accuracy of pressure force in collaborative control.
[0027] It is understood that the multivariable control algorithm is not limited to fuzzy PID, for example: Decoupling control algorithm: by constructing a feedforward decoupling network, the coupling terms between the compaction force control loop and the diameter control loop are offset, and the multivariable system is converted into two independent single-input single-output (SISO) systems for control; Model predictive control (MPC) algorithm: a dynamic state space model of the cotton mold compression process is established, and in each control period, the optimal rocker arm torque and speed command sequence in the future time domain is solved by rolling optimization.
[0028] The above algorithms can be used to achieve the purpose of collaborative control of the present application.
[0029] When the diameter of the cotton mold D a reaches the first set diameter D 1 , the system switches to the diameter maintaining and pressure relaxing stage, and the controller locks the target diameter D s as the first set diameter D 1 , maintains the diameter constant, and allows the cotton mold compaction force P a to naturally decrease, and when the change rate of the cotton mold compaction force P a is detected to be lower than a threshold value within 5 seconds, it is determined that the pressure is stable.
[0030] Enter the final sizing stage, and the controller instructs the rocker arm servo motor to position to the angle corresponding to the final diameter, the second target diameter D 2 , and keep for a preset time t , complete the final sizing of the cotton mold.
[0031] In addition, in one preferred embodiment of the present embodiment, as Figure 3 shown, it is a schematic diagram of the parameter change trend of the whole cycle of the cotton mold forming in the embodiment of the present application, which shows that in the four continuous stages of the initial winding, the density ramping and the diameter collaborative growth, the diameter maintaining and the pressure relaxing, and the final sizing, the cotton mold compaction force P a and the diameter of the cotton mold D a have the dynamic response law and collaborative relationship under the double-mode switching strategy.
[0032] The preferred embodiments of the application disclosed above are only used to illustrate the present application, the preferred embodiments do not describe all the details, and the application is not limited to the specific embodiments described, obviously, according to the content of the specification, many modifications and changes can be made, the specification selects and describes these embodiments, in order to better explain the principles and practical application of the application, so that those skilled in the art can well understand and utilize the application, the application is limited by the claims and the whole scope and equivalents thereof.
Claims
1. A pressure-diameter coordinated control system for a seed cotton circular die baler, characterized in that, include: The state sensing module is configured to collect state parameters during the cotton mold forming process in real time, and it is equipped with features for indirectly detecting the compressive strength of the cotton mold. P a Torque sensor and for detecting cotton mold diameter D a Angle encoder; The decision control module, which is signal-connected to the state perception module, is configured as follows: (1) Identify the current forming stage based on the state parameters, and switch the control system between density priority control mode and diameter priority control mode; (2) In the density priority control mode, the target pressure is set according to the preset rules. P s And using preset functional relationships D s =f( P s Calculate the corresponding target diameter D s ; (3) In the diameter priority control mode, the target diameter is set. D s It is a constant value, and receives the cotton molding force. P a The feedback signal is monitored for changes in real time; (4) The decision control module further includes a collaborative controller, used to base its decision on the target value ( P s , D s ) and the actual value ( P a , D a The deviation between the two is used to generate control commands for driving the rocker arm servo drive mechanism through a multivariable control algorithm; The execution drive module is signal-connected to the decision control module, and includes a rocker arm servo drive mechanism for coordinating the adjustment of the diameter and pressing force of the cotton mold according to the control command.
2. The system according to claim 1, characterized in that, The functional relationship D s = f( Ps It can be represented as a linear function: D s = D min + k ×( P s - P min ) in, D min To preset the minimum diameter, P min To preset the minimum pressure, k This is the proportionality coefficient.
3. The system according to claim 1, characterized in that, The switching condition for the density-priority control mode and the diameter-priority control mode is the diameter of the cotton mold. D a To achieve the preset first target diameter value D 1 .
4. The system according to claim 1, characterized in that, The multivariable control algorithm includes fuzzy PID control, decoupling control, or model predictive control.
5. The system according to claim 1, characterized in that, The decision control module is configured to: in diameter-priority control mode, when the cotton molding strength... P a When the rate of change is lower than a preset threshold over a continuous period of time, the cotton molding strength is determined. P a It has stabilized.
6. A pressure-diameter coordinated control method for a seed cotton circular die baler, applied to the system described in any one of claims 1-5, characterized in that, Includes the following steps: Step S1: Initial winding, control the rocker arm servo mechanism to move to the initial position, and apply a constant initial torque. T 0 , making the initial pressure force P 0 This allows the seed cotton to stably wrap and form the initial cotton core; Step S2: Density ramp-up and diameter increase in tandem, entering the density-priority control mode to control the target pressure. P s It grows at a preset rate over time, while simultaneously utilizing the preset functional relationship. D s =f( P s Real-time calculation of target diameter D s The cotton molding strength is controlled through multivariable closed-loop control. P a and the diameter of the cotton mold D a Track the target pressure force respectively P s and target diameter D s ; Step S3: Diameter maintenance and pressure relaxation, when the diameter of the cotton mold... D a Reaching the first set diameter D 1 When switching to the diameter priority control mode, the target diameter is set. D s Locked to the first set diameter D 1 Control the rocker arm servo mechanism to maintain the first set diameter D 1 Constant, and monitor the molding strength of the cotton. P a The relaxation process continues until the rate of change is below a preset threshold, at which point it is considered to be stabilizing. Step S4: Final shaping, when the cotton molding strength... P a After stabilization, control the rocker arm servo mechanism to adjust the diameter of the cotton mold. D a Adjust to the second target diameter D 2 and maintain the preset time. t Apply pressure and shape to complete the final shaping of the cotton mold.