Automatic mulching film discharging and propelling device and method thereof

Abstract

The invention discloses an automatic mulching film discharging and propelling device and method, and belongs to the technical field of agricultural automatic production, and the method comprises the steps that S1, a propelling system, a speed measuring unit, a discharging servo motor and a central controller are arranged, and the speed measuring unit is installed on the propelling system and used for measuring and sending a propelling speed reference signal to the central controller; the discharging servo motor is used for driving the mulching film roll material to rotate, the discharging servo motor is integrated with an encoder and a current sensor, the encoder is used for feeding back a motor real-time angular velocity signal to the central controller, and the current sensor is used for feeding back a motor real-time current signal to the central controller; the central controller is electrically connected with the speed measuring unit, the encoder, the current sensor and a driver of the blanking servo motor, the dependence on a fixed parameter model is eliminated, the self-adaptive control on time-varying parameters is realized, and the control precision in the whole change process of the roll diameter from full roll to roll core is ensured.

Description

Technical Field

[0001] This invention relates to the field of agricultural automated production, specifically to an automated mulch film feeding and propulsion device and method. Background Technology

[0002] In modern automated agricultural production, the laying of plastic film is a crucial step. Automated plastic film propulsion devices face a core physical challenge during the conveying and laying process: the plastic film roll is a typical controlled object with time-varying parameters. As the laying operation progresses, the diameter and moment of inertia of the plastic film roll continuously decrease.

[0003] Traditional control technologies, such as mechanical passive braking devices or simple open-loop speed control, cannot adapt to this time-varying characteristic. When the speed of the propulsion device fluctuates, especially at the moment of start-up and shutdown, these traditional systems, lacking dynamic compensation algorithms for time-varying inertia, cannot achieve dynamic decoupling between the propulsion speed and the feeding speed. This leads to a mismatch between the propulsion device and the feeding speed of the mulch film, which can easily cause sudden changes in the tension of the flexible mulch film. The adverse consequences include the mulch film breaking, causing irreversible tensile deformation, or the mulch film piling up and clogging when the propulsion speed slows down, seriously affecting the continuity of automated operations and the quality of mulch film laying. Therefore, the industry urgently needs a low-cost, high-precision control solution to achieve constant mulch film tension and ensure precise synchronization between the feeding speed and the propulsion speed.

[0004] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide an automated mulch film feeding and propulsion device and method to solve the problems mentioned in the background art.

[0006] The technical solution of the present invention includes: S1. A propulsion system, a speed measurement unit, a feeding servo motor, and a central controller are set up. The speed measurement unit is installed in the propulsion system to measure and send the propulsion speed reference signal to the central controller. The feeding servo motor is used to drive the rotation of the mulch film roll. The feeding servo motor integrates an encoder and a current sensor. The encoder is used to feed back the real-time angular velocity signal of the motor to the central controller, and the current sensor is used to feed back the real-time current signal of the motor to the central controller. The central controller is electrically connected to the speed measurement unit, the encoder, the current sensor, and the driver of the feeding servo motor. S2. Start the propulsion system. The central controller receives the propulsion speed reference signal, the motor's real-time angular velocity signal, and the motor's real-time current signal in real time. S3. The central controller operates dual observers to estimate the system state, including: operating a roll diameter state observer, which estimates the estimated roll diameter of the mulch film in real time based on the propulsion speed reference signal and the real-time angular velocity signal of the motor; and operating a tension disturbance observer, which calculates the actual output torque based on the real-time current signal of the motor, and uses the inertial compensation torque calculated from the rate of change of the estimated roll diameter and the propulsion speed reference signal, and subtracts the inertial compensation torque from the actual output torque to estimate the estimated tension torque; S4. The central controller performs multivariable decoupling and generates composite control commands, which include: speed synchronization commands based on propulsion speed reference signals and estimated roll diameter; tension correction torque commands generated by comparing estimated tension torque with the system's preset target tension torque; and inertial compensation torque as a feedforward signal. S5. The central controller uses the speed synchronization command as the speed loop target of the feeding servo motor, and superimposes the tension correction torque command and the inertia compensation torque as a torque compensation signal to send to the driver of the feeding servo motor to achieve constant tension synchronous feeding.

[0007] Preferably, in S3, the step of the tension disturbance observer calculating the inertial compensation torque includes: Based on the estimated roll diameter, the internal physical model is consulted to estimate the current estimated moment of inertia of the plastic film roll; The rate of change of the propulsion speed reference signal is calculated to determine the propulsion acceleration. The target angular acceleration is calculated based on the propulsion acceleration and the estimated roll diameter. The estimated moment of inertia is multiplied by the target angular acceleration to calculate the inertia compensation torque.

[0008] Preferably, in S3, the roll diameter status observer is based on the kinematic principle that the linear velocity of the ground film is equal to the reference signal of the propulsion speed. By comparing the reference signal of the propulsion speed and the real-time angular velocity signal of the motor, the estimated roll diameter is calculated in reverse.

[0009] Preferably, the target tension torque in S4 is calculated from the target tension value preset by the human-machine interface and the estimated roll diameter.

[0010] Preferably, the speed measurement unit is one of a global positioning system, a radar speedometer, or a wheel encoder.

[0011] Preferably, the central controller is a programmable logic controller or an embedded microcontroller.

[0012] An automated mulch film feeding and propulsion device includes: Propulsion system; The speed measurement unit, installed in the propulsion system, is used to measure and transmit the propulsion speed reference signal; The feeding servo motor is used to drive the rotation of the mulch film roll. The feeding servo motor integrates an encoder and a current sensor. The encoder is used to provide feedback on the real-time angular velocity signal of the motor, and the current sensor is used to provide feedback on the real-time current signal of the motor. The central controller is electrically connected to the speed measurement unit, encoder, current sensor, and driver for the unloading servo motor. The central controller is configured as follows: It receives propulsion speed reference signals, motor real-time angular velocity signals, and motor real-time current signals in real time. Based on the propulsion speed reference signal and the real-time angular velocity signal of the motor, the estimated roll diameter of the mulch film is estimated. Based on the rate of change of the real-time current signal of the motor, the estimated roll diameter, and the reference signal of the propulsion speed, the estimated tension torque and the inertia compensation torque are estimated. Based on the estimated roll diameter, estimated tension torque, inertia compensation torque, and preset target tension torque, a composite control command is generated and sent to the driver of the feed servo motor. The composite control command includes speed synchronization command and torque compensation signal.

[0013] Preferably, the central controller includes: The roll diameter status observer module is used to estimate the roll diameter based on the propulsion speed reference signal and the real-time angular velocity signal of the motor. The inertial feedforward compensation module is used to calculate the inertial compensation torque based on the rate of change of the estimated roll diameter and propulsion speed reference signals. The tension disturbance observer module is used to estimate the tension torque based on the actual output torque and inertia compensation torque fed back from the real-time current signal of the motor.

[0014] Preferably, the central controller also includes: The tension adaptive controller module is used to receive the preset target tension value, calculate the target tension torque based on the estimated roll diameter, compare the target tension torque with the estimated tension torque, and generate a tension correction torque command. Among them, the torque compensation signal in the composite control command is formed by superimposing the inertial compensation torque and the tension correction torque command.

[0015] This invention provides an automated mulch film feeding and propulsion device and method, which, compared with the prior art, has the following improvements and advantages: 1. This solution uses a roll diameter state observer built into the central controller. Based on the propulsion speed reference signal and the real-time angular velocity signal of the motor, and utilizing the kinematic principle that the linear velocity of the mulch film equals the propulsion speed, the estimated roll diameter of the mulch film is calculated in real time. This design enables the control system to perceive the changes in the physical parameters of the controlled object, the mulch film roll, in real time. Whether it is the estimated moment of inertia required to calculate the inertia compensation torque or the target tension torque required to calculate the tension adaptive controller module, it is all based on this estimated roll diameter. This design eliminates the dependence on fixed parameter models, realizes adaptive control of time-varying parameters, and ensures control accuracy throughout the entire process of the roll diameter changing from full roll to core roll. 2. This solution adopts a dual-observer algorithm strategy. First, the roll diameter state observer solves the time-varying parameter problem. Second, the tension disturbance observer, or tension disturbance observer module, cleverly solves the problem of tension signal acquisition. This observer uses the current sensor built into the feeding servo motor to feed back the real-time current signal of the motor and converts it into the actual output torque. By subtracting the inertial compensation torque calculated by the inertial feedforward compensation module from the actual output torque, i.e., the torque component used to overcome acceleration or deceleration, the difference is accurately estimated as the estimated tension torque. This design essentially uses the servo motor itself as a high-precision torque sensor, replacing the external physical tension sensor with a pure algorithm, which significantly reduces hardware costs while greatly improving the reliability and durability of the system in dusty and vibrating environments. 3. By using feedforward intervention of inertial compensation torque, most of the motor torque is used to overcome inertia, rather than passively responding to load changes by stretching the mulch film; this achieves complete decoupling of speed control and tension control, suppresses tension abrupt changes in the dynamic process, and ensures constant tension synchronous feeding. Attached Figure Description

[0016] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the device; Figure 2 This is a schematic diagram of the plastic film roll support and its connection structure; Figure 3 This is a schematic diagram of the central controller and its overall connection structure; Figure 4 This is a schematic diagram of the process flow of the method of the present invention.

[0017] In the diagram: 100, propulsion system; 110, speed measurement unit; 200, mulch film roll support; 300, feeding servo motor; 310, encoder; 320, current sensor; 400, central controller; 500, roll diameter status observer; 600, inertial feedforward compensation module; 700, tension disturbance observer; 900, human-machine interface. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0019] Example 1, please refer to Figure 1-4 This invention provides an automated method for dispensing and advancing plastic film, comprising: S1. A propulsion system 100, a speed measurement unit 110, a feeding servo motor 300, and a central controller 400 are configured. The speed measurement unit 110 is installed in the propulsion system 100 and is used to measure and send a propulsion speed reference signal to the central controller 400. The feeding servo motor 300 is used to drive the rotation of the mulch film roll. The feeding servo motor 300 integrates an encoder 310 and a current sensor 320. The encoder 310 is used to feed back the real-time angular velocity signal of the motor to the central controller 400, and the current sensor 320 is used to feed back the real-time current signal of the motor to the central controller 400. The central controller 400 is electrically connected to the speed measurement unit 110, the encoder 310, the current sensor 320, and the driver of the feeding servo motor 300. The target tension value is preset via the human-machine interface. This value is stored in the storage unit of the central controller 400; The encoder 310 and the current sensor 320 are both integrated inside the unloading servo motor 300. The encoder 310 is used to measure the angular position and angular velocity of the motor rotor in real time, and the current sensor 320 is used to collect the motor winding current in real time and convert it into the actual output torque of the motor. S2. Start the propulsion system 100. The central controller 400 receives the propulsion speed reference signal, the motor's real-time angular velocity signal, and the motor's real-time current signal in real time. S3. The central controller 400 operates dual observers to estimate the system state, including: an operating roll diameter state observer 500, which estimates the estimated roll diameter of the mulch film in real time based on the propulsion speed reference signal and the real-time angular velocity signal of the motor; and an operating tension disturbance observer 700, which calculates the actual output torque based on the real-time current signal of the motor, and estimates the estimated tension torque by subtracting the inertial compensation torque from the actual output torque using the inertial compensation torque calculated from the rate of change of the estimated roll diameter and the propulsion speed reference signal. S4 and the central controller 400 perform multivariable decoupling and generate composite control commands. The composite control commands include: a speed synchronization command based on the propulsion speed reference signal and the estimated roll diameter; a tension correction torque command generated by comparing the estimated tension torque with the system's preset target tension torque; and an inertial compensation torque as a feedforward signal. S5. The central controller 400 uses the speed synchronization command as the speed loop target of the feeding servo motor 300, and superimposes the tension correction torque command with the inertia compensation torque as a torque compensation signal to send to the driver of the feeding servo motor 300 to achieve constant tension synchronous feeding. This design, which separates commands, with speed commands sent to the speed loop and torque compensation signals sent to the torque loop, achieves dynamic decoupling between feeding speed control and tension control because the inertial compensation torque, acting as a feedforward signal, actively cancels the inertial effects during start-up, shutdown, or speed changes. This ensures that even when the feed speed Vref changes rapidly, the mulch film can still achieve high-precision constant tension synchronous feeding, preventing breakage or stacking caused by sudden tension changes. This invention provides an automated method for feeding and advancing plastic film, aiming to solve the problems in existing technologies where the plastic film roll, as a time-varying parameter controlled object, experiences continuous changes in its roll diameter and moment of inertia during laying, making it difficult to match the advancing speed with the feeding speed. This is especially problematic during start-up, shutdown, and speed changes, easily leading to sudden tension changes, film breakage, or stacking and blockage. The method of this invention, through hardware settings in step S1, allows the central controller 400 to acquire real-time advancing speed reference signals, real-time motor angular velocity signals, and real-time motor current signals after the advancement system 100 is started in step S2. The core of this method lies in step S3, where the central controller 400, by running a dual-observer algorithm, estimates the plastic film in real-time without relying on external physical tension sensors. The estimated roll diameter and estimated tension torque are calculated. Based on these internal estimates, the central controller 400 performs multivariate decoupling in S4, generating a composite control command that includes speed synchronization command, tension correction torque command, and inertia compensation torque. In S5, the central controller 400 uses the speed synchronization command as the speed loop target of the unloading servo motor 300 to ensure that the unloading line speed strictly follows the propulsion speed. At the same time, the tension correction torque command is used to correct the steady-state tension and inertia compensation torque in a closed loop, and is used to feed forward to cancel the superposition of dynamic disturbances, and is sent to the driver as a torque compensation signal. This method achieves decoupling of propulsion speed and tension control through algorithms, ensuring constant tension and high-precision synchronous unloading under all working conditions.

[0020] In S3, the steps for the tension disturbance observer 700 to calculate the inertial compensation torque include: Based on the estimated roll diameter, the internal physical model is consulted to estimate the current estimated moment of inertia of the plastic film roll; The rate of change of the propulsion speed reference signal is calculated to determine the propulsion acceleration. The target angular acceleration is calculated based on the propulsion acceleration and the estimated roll diameter. The estimated moment of inertia is multiplied by the target angular acceleration to calculate the inertia compensation torque; Input source: The input to this calculation process is the estimated roll diameter from the roll diameter state observer 500. and the propulsion speed reference signal from the speed measurement unit 110. Logical steps: Step 1, Estimation of moment of inertia: The central controller 400... Query the internally stored physical model to estimate the current estimated moment of inertia of the plastic film roll. Step 2, Acceleration Calculation: Central Controller 400 pairs Perform differentiation, i.e., find the rate of change, to calculate the propulsive acceleration. Step 3, Angular acceleration conversion: The central controller 400 calculates angular acceleration based on kinematic relationships. The target angular acceleration that the servo motor for feeding 300 needs to achieve is calculated. Step 4, Torque Calculation: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] and Multiplication, that is The inertial compensation torque was calculated. Output and flow: The final output of the process is the inertial compensation torque, which is then used as a feedforward signal. On the one hand, it is transmitted to the tension disturbance observer 700 to estimate the tension torque. On the other hand, it is directly superimposed with the tension correction torque command and sent as a torque compensation signal to the driver of the unloading servo motor 300. Based on the above scheme, the premise of estimating the tension torque in S3 is to accurately calculate the inertial compensation torque so as to separate it from the total output torque of the motor. This embodiment provides a specific step for calculating the inertial compensation torque: The central controller 400 queries the physical model of the mulch film roll stored in its internal storage, such as a function or lookup table describing the relationship between the moment of inertia J and the roll diameter R, based on the estimated roll diameter updated in real time by the roll diameter state observer 500, to estimate the current estimated moment of inertia of the mulch film roll; at the same time, the central controller 400 monitors the received propulsion speed reference signal in real time or calculates its rate of change, and calculates the propulsion acceleration of the propulsion system 100; the controller calculates the target angular acceleration that the feeding servo motor 300 needs to achieve based on the propulsion acceleration and the current estimated roll diameter; then, the central controller 400 multiplies the estimated moment of inertia with the target angular acceleration to calculate the inertial compensation torque; this torque is used as a feedforward signal to actively counteract the nonlinear dynamic disturbance caused by the change in the moment of inertia of the mulch film roll when the propulsion system 100 starts, stops or changes speed.

[0021] In S3, the roll diameter status observer 500 is based on the kinematic principle that the linear velocity of the mulch film is equal to the reference signal of the propulsion speed. By comparing the reference signal of the propulsion speed and the real-time angular velocity signal of the motor, it reverses the calculation to estimate the roll diameter. As a specific implementation of the roll diameter state observer 500 in S3 above, this observer module is based on a fundamental kinematic principle: in an ideal synchronous feeding process, the actual linear velocity of the mulch film must be strictly equal to the ground travel speed of the propulsion system 100, i.e., the propulsion speed reference signal; the linear velocity of the mulch film is also equal to the product of the real-time angular velocity of the feeding servo motor 300 and the estimated roll diameter of the current mulch film; therefore, given the two quantities of the propulsion speed reference signal and the real-time angular velocity signal of the motor, the central controller 400 can calculate the estimated roll diameter by reverse deduction, i.e., the estimated roll diameter is equal to the propulsion speed reference signal divided by the real-time angular velocity of the motor, i.e. The system reconstructs the current estimated roll diameter in real time. In this way, the system replaces expensive and easily damaged physical diameter measuring sensors, such as ultrasonic or laser sensors, with pure algorithms to acquire the key time-varying parameter of roll diameter in real time. In an optional implementation, in order to prevent measurement noise from causing drastic fluctuations in the estimated value, the calculated estimated roll diameter signal can also be smoothed by low-pass filtering.

[0022] The target tension torque in S4 is calculated from the target tension value preset by the human-machine interface 900 and the estimated roll diameter; The preset target tension value is a constant physical quantity, such as 25N, representing the expected tension that the mulch film should maintain during installation. It is the core control target to ensure the quality of mulch film installation. Logical relationship and source: This target tension value is set by the operator through the human-machine interface (HMI) and is the only external setpoint for tension closed-loop control. Target tension torque. Through formula The result is obtained through dynamic calculation, where That is, the preset target tension value, and It is the real-time estimated roll diameter from the roll diameter status observer 500; Decision function: The dynamically calculated target tension torque is then sent to the tension adaptive controller module as a benchmark for comparison with the estimated tension torque, and the comparison result is used to generate the tension correction torque command. In S4 above, when the central controller 400 generates the tension correction torque command, it needs the target tension torque as the reference for closed-loop control. In this embodiment, the target tension torque is a dynamically calculated value, calculated as follows: The operator presets the desired physical target tension value of the mulch film through the human-machine interface 900, for example, setting it to 25N. This value represents the constant tension that is desired to be applied to the mulch film. When the central controller 400 is running, it acquires the target tension value and combines it with the roll diameter status observer 500, such as the estimated roll diameter provided in real time in S3. Based on the principle that torque equals force multiplied by lever arm, the controller multiplies the target tension value by the estimated roll diameter to calculate the target tension torque that the motor needs to output to maintain the target tension under the current roll diameter. Since the estimated roll diameter continuously decreases during the feeding process, the target tension torque will also be adjusted accordingly to ensure that the physical tension of the mulch film and the target tension value remain constant throughout the feeding process.

[0023] The speed measurement unit 110 is one of a global positioning system, a radar speedometer, or a wheel encoder 310; Preferably, the wheel encoder 310 more accurately refers to the wheel speed encoder 310, and is used to distinguish the encoder 310 mounted on the unloading servo motor 300; As a specific implementation of the speed measurement unit 110, the core function of this unit is to accurately measure the ground travel speed of the propulsion system 100, such as a tractor or an autonomous mobile chassis, and send it as a propulsion speed reference signal to the central controller 400. This unit can be implemented using various technologies. In one embodiment, the unit is a global positioning system, such as GPS or a high-precision BeiDou RTK positioning system, which can provide high-precision real-time ground speed information. In another embodiment, the unit can be a radar speedometer, which measures the speed of the propulsion system 100 relative to the ground through the Doppler effect. In yet another embodiment, the unit can also be a wheel encoder 310 installed on the non-drive wheels of the propulsion system 100, which calculates the travel speed of the propulsion system 100 by measuring the wheel rotation speed and the known wheel circumference.

[0024] The central controller 400 is a programmable logic controller or an embedded microcontroller; As a specific implementation of the aforementioned central controller 400, this controller is the core of the entire control system, responsible for receiving various sensor signals from S1, running the dual observer algorithm of S3 and the multivariable decoupling algorithm of S4, and generating the composite control instructions of S5. In this embodiment, the central controller 400 can be a programmable logic controller (PLC). PLCs are suitable for harsh industrial or agricultural operating environments and have high reliability, strong anti-interference capabilities, and convenient programming characteristics. In another embodiment, the central controller 400 can also be an embedded microcontroller or a dedicated digital signal processor, suitable for equipment with high requirements for cost and size, and requiring compact and integrated design.

[0025] Example 2, please refer to Figure 1-3 An automated mulch film feeding and propulsion device includes: Propulsion System 100; The speed measurement unit 110 is installed in the propulsion system 100 and is used to measure and send the propulsion speed reference signal. The feeding servo motor 300 is used to drive the rotation of the mulch film roll. The feeding servo motor 300 integrates an encoder 310 and a current sensor 320. The encoder 310 is used to feed back the real-time angular velocity signal of the motor, and the current sensor 320 is used to feed back the real-time current signal of the motor. The central controller 400 is electrically connected to the speed measurement unit 110, encoder 310, current sensor 320, and driver for the unloading servo motor 300. The central controller 400 is configured as follows: It receives propulsion speed reference signals, motor real-time angular velocity signals, and motor real-time current signals in real time. Based on the propulsion speed reference signal and the real-time angular velocity signal of the motor, the estimated roll diameter of the mulch film is estimated. Based on the rate of change of the real-time current signal of the motor, the estimated roll diameter, and the reference signal of the propulsion speed, the estimated tension torque and the inertia compensation torque are estimated. The input to this observer process is the real-time motor current signal fed back from the current sensor 320 integrated in the unloading servo motor 300, and the inertial compensation torque calculated by the inertial feedforward compensation module 600. The logical steps are as follows: Step 1: The tension disturbance observer 700 converts the real-time motor current signal into the actual output torque Tactual through the known motor torque coefficient Kt, determined by the motor parameters. Step 2: The tension disturbance observer 700 performs a subtraction operation, i.e., Ttension_est = Tactual − Tinertia_comp. Step 3: The calculation result is low-pass filtered to remove high-frequency noise, yielding the final estimated tension torque. Output and flow: The final output of the process is the estimated tension torque, which is then transmitted to the tension adaptive controller module as a feedback signal for tension closed-loop control. Based on the estimated roll diameter, estimated tension torque, inertia compensation torque, and preset target tension torque, a composite control command is generated and sent to the driver of the feed servo motor 300. The composite control command includes speed synchronization command and torque compensation signal. The present invention also provides an automated mulch film feeding and propulsion device for implementing the aforementioned method; the device includes a propulsion system 100, such as an autonomous driving tractor, and a speed measurement unit 110 mounted on the propulsion system 100, such as a Beidou RTK system; the device also includes a feeding servo motor 300, the output shaft of which is connected to the rotating shaft of the mulch film roll support 200 for driving the mulch film roll to rotate, the servo motor integrating an encoder 310 for feeding back the real-time angular velocity of the motor and a current sensor 320 for feeding back the real-time current of the motor; the core of the device is a central controller 400, such as a PLC, which communicates with the speed measurement unit 110, the encoder 310 of the servo motor, the current sensor 320, and the driver of the servo motor via electrical connections, such as a bus or I / O; The central controller 400 is configured to perform the following functions via internally embedded control software or logic: The system receives in real time the propulsion speed reference signal sent by the speed measurement unit 110, the real-time angular velocity signal of the motor fed back by the encoder 310, and the real-time current signal of the motor fed back by the current sensor 320. The roll diameter estimation algorithm is run to estimate the roll diameter of the mulch film based on the propulsion speed reference signal and the real-time angular velocity signal of the motor. The running torque observation and compensation algorithm, based on the real-time current signal of the motor, is converted into the actual output torque, the rate of change of the estimated roll diameter and the propulsion speed reference signal, i.e. the propulsion acceleration, and then estimates the estimated tension torque and inertia compensation torque. The decoupled control algorithm is run to generate a composite control command based on the estimated roll diameter, estimated tension torque, inertia compensation torque, and target tension torque preset by the human-machine interface 900, and sends it to the driver of the unloading servo motor 300. The composite control command includes a speed synchronization command for speed synchronization, and a torque compensation signal composed of the superposition of inertia compensation torque and tension correction torque.

[0026] The central controller 400 includes: The roll diameter status observer 500 module is used to estimate the roll diameter based on the propulsion speed reference signal and the real-time angular velocity signal of the motor. The purpose of the roll diameter state observer 500 is to track the continuously changing roll diameter of the mulch film during the laying process in real time and with high precision without using external physical sensors, thus solving the problem of time-varying system parameters. Logical structure and data flow: This model receives the propulsion speed reference signal Vref from the speed measurement unit 110 and the real-time angular velocity ωactual of the motor, with the encoder 310 as input. Its core logical structure is based on the kinematic relationship Vline=ωactual⋅Rest, where the linear velocity of the mulch film equals the propulsion speed. The formula for estimating the roll diameter, Rest=Vref / ωactual, is obtained by inversely solving this equation. Physical relationship represented: This model abstracts and utilizes the ideal kinematic relationship of no slippage and speed synchronization between the mulch film and the ground during the mulch film laying process, thereby realizing soft measurement, i.e., algorithm estimation, of the key time-varying physical parameter, the roll diameter. The inertial feedforward compensation module 600 is used to calculate the inertial compensation torque based on the estimated roll diameter and the rate of change of the propulsion speed reference signal. The Tension Disturbance Observer 700 module is used to estimate the tension torque based on the actual output torque and inertia compensation torque fed back from the real-time current signal of the motor. The actual output torque is calculated by multiplying the real-time current signal of the motor with the inherent torque constant Kt of the servo motor. This torque constant Kt is a physical parameter that describes the linear relationship between the motor current and the output torque. In the aforementioned device, the control logic within the central controller 400, such as the control software, can be divided into multiple collaborative functional modules. The central controller 400 includes a roll diameter status observer 500 module; this module receives the propulsion speed reference signal and the real-time angular velocity signal of the motor as input, and calculates the current estimated roll diameter based on kinematic principles as output. The central controller 400 also includes an inertial feedforward compensation module 600; this module receives the estimated roll diameter signal from the roll diameter state observer 500 module and the propulsion speed reference signal from the speed measurement unit 110; this module queries the physical model based on the estimated roll diameter to obtain the estimated moment of inertia, and calculates the propulsion acceleration by calculating the rate of change of the propulsion speed reference signal, and then calculates the inertial compensation torque. The central controller 400 also includes a tension disturbance observer 700 module; this module receives the actual output torque fed back by the servo motor, converts it from the real-time current signal of the motor and the inertial compensation torque from the inertial feedforward compensation module 600; this module estimates the estimated tension torque reflecting the actual tension and friction disturbance of the mulch film by performing a subtraction operation, the actual output torque minus the inertial compensation torque, and uses it as the feedback signal for tension closed-loop control.

[0027] The central controller 400 also includes: The tension adaptive controller module is used to receive the preset target tension value, calculate the target tension torque based on the estimated roll diameter, compare the target tension torque with the estimated tension torque, and generate a tension correction torque command. Among them, the torque compensation signal in the composite control command is formed by superimposing the inertial compensation torque and the tension correction torque command; Based on the above module division, the central controller 400 also includes a tension adaptive controller module, such as a PID controller algorithm module. This module is used to implement closed-loop feedback control of tension. This module receives the target tension value preset by the human-machine interface 900 and receives the real-time estimated roll diameter from the roll diameter state observer 500 module. Based on these two inputs, this module calculates the dynamically changing target tension torque. This module compares this target tension torque with the estimated tension torque from the tension disturbance observer 700 module as the actual feedback value and calculates the error between the two. Based on this error, this module generates a tension correction torque command through PID and other control algorithms. This command is used to accurately compensate for steady-state errors and slow time-varying disturbances such as friction. When the central controller 400 sends a composite control command to the servo drive, its output torque compensation signal is composed of two superimposed parts: one part is the inertial compensation torque from the inertial feedforward compensation module 600, which is used to handle dynamic disturbances during start-up, stop-and-go and speed change, fast loop; the other part is the tension correction torque command from the tension adaptive controller module, which is used to handle steady-state tension error, slow loop; the two work together to achieve constant tension control.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An automated mulch underlay advancing method, characterized by, The method comprises the following steps: S1, setting a propulsion system (100), a speed measurement unit (110), a discharging servo motor (300), and a central controller (400), wherein the speed measurement unit (110) is installed on the propulsion system (100) and used for measuring and sending a propulsion speed reference signal to the central controller (400); the discharging servo motor (300) is used for driving the mulch roll to rotate, the discharging servo motor (300) is integrated with an encoder (310) and a current sensor (320), the encoder (310) is used for feeding back a real-time angular velocity signal of the motor to the central controller (400), and the current sensor (320) is used for feeding back a real-time current signal of the motor to the central controller (400); the central controller (400) is electrically connected with the speed measurement unit (110), the encoder (310), the current sensor (320), and a driver of the discharging servo motor (300); S2, starting the propulsion system (100), and the central controller (400) receiving the propulsion speed reference signal, the real-time angular velocity signal of the motor, and the real-time current signal of the motor in real time; S3, the central controller (400) running double observers to estimate the system state, comprising: running a roll diameter state observer (500) to estimate the roll diameter of the mulch in real time based on the propulsion speed reference signal and the real-time angular velocity signal of the motor; and running a tension disturbance observer (700) to convert the real-time current signal of the motor into an actual output torque, and to estimate an estimated tension torque by subtracting an inertia compensation torque calculated from the estimated roll diameter and the rate of change of the propulsion speed reference signal from the actual output torque; S4, the central controller (400) performing multivariable decoupling to generate a composite control instruction, the composite control instruction comprising: a speed synchronization instruction calculated based on the propulsion speed reference signal and the estimated roll diameter; a tension correction torque instruction generated by comparing the estimated tension torque with a system preset target tension torque; and the inertia compensation torque as a feedforward signal; S5, the central controller (400) taking the speed synchronization instruction as a speed loop target of the discharging servo motor (300), and superimposing the tension correction torque instruction and the inertia compensation torque to send a torque compensation signal to the driver of the discharging servo motor (300) to realize constant tension synchronous discharging.

2. The automated mulch underlay advancing method of claim 1, wherein, In S3, the steps of the tension disturbance observer (700) calculating the inertia compensation torque comprise: querying an internal physical model according to the estimated roll diameter to estimate the current estimated moment of inertia of the mulch roll; calculating the propulsion acceleration by taking the rate of change of the propulsion speed reference signal; converting the target angular acceleration according to the propulsion acceleration and the estimated roll diameter; multiplying the estimated moment of inertia and the target angular acceleration to calculate the inertia compensation torque.

3. The automated mulch underlay advancing method according to claim 1 or 2, wherein, In S3, the roll diameter state observer (500) estimates the estimated roll diameter by comparing the propulsion speed reference signal and the real-time angular velocity signal of the motor based on the kinematics principle that the linear speed of the mulch is equal to the propulsion speed reference signal.

4. The automated mulch underlay advancing method of claim 1, wherein, In S4, the target tension torque is calculated from the target tension value preset by a human-machine interface (900) and the estimated roll diameter.

5. The automated mulch underlay advancing method of claim 1, wherein, The speed measurement unit (110) is one of a global positioning system, a radar speedometer or a wheel encoder (310).

6. The automated mulch underlay advancing method of claim 1, wherein, The central controller (400) is a programmable logic controller or an embedded microcontroller.

7. An automatic mulch film underlaying and advancing device applied to the automatic mulch film underlaying and advancing method of any one of claims 1-6, characterized in that, It comprises: a propulsion system (100); a speed measurement unit (110) installed on the propulsion system (100) for measuring and sending a propulsion speed reference signal; a servo motor (300) for driving the mulch film roll to rotate, the servo motor (300) being integrated with an encoder (310) and a current sensor (320), the encoder (310) being used to feed back a real-time angular velocity signal of the motor, and the current sensor (320) being used to feed back a real-time current signal of the motor; a central controller (400) electrically connected to the speed measurement unit (110), the encoder (310), the current sensor (320) and a driver of the servo motor (300); The central controller (400) is configured to: receive the propulsion speed reference signal, the real-time angular velocity signal of the motor and the real-time current signal of the motor in real time; estimate a roll diameter of the mulch film based on the propulsion speed reference signal and the real-time angular velocity signal of the motor; estimate an estimated tension torque and an inertia compensation torque based on the real-time current signal of the motor, the estimated roll diameter and a change rate of the propulsion speed reference signal; generate and send a composite control instruction to the driver of the servo motor (300) based on the estimated roll diameter, the estimated tension torque, the inertia compensation torque and a preset target tension torque, the composite control instruction comprising a speed synchronization instruction and a torque compensation signal.

8. An automated mulch underfeed propulsion device according to claim 7, wherein, The central controller (400) comprises: a roll diameter state observer (500) module for estimating the estimated roll diameter based on the propulsion speed reference signal and the real-time angular velocity signal of the motor; an inertia feedforward compensation module (600) for calculating the inertia compensation torque based on the estimated roll diameter and the change rate of the propulsion speed reference signal; a tension disturbance observer (700) module for estimating the estimated tension torque based on an actual output torque fed back by the real-time current signal of the motor and the inertia compensation torque.

9. An automated mulch underfeed propulsion device according to claim 8, wherein, The central controller (400) further comprises: a tension adaptive controller module for receiving a preset target tension value, calculating a target tension torque based on the estimated roll diameter, comparing the target tension torque with the estimated tension torque, and generating a tension correction torque instruction; The torque compensation signal in the composite control instruction is superimposed by the inertia compensation torque and the tension correction torque instruction.

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