Automatic film cutting and soil covering type pepper direct seeding machine control method and control system

Abstract

The application provides an automatic film cutting and soil covering type pepper direct seeding machine control method and a control system, and the automatic film cutting and soil covering type pepper direct seeding machine control method is controlled according to the following aspects: (1) seed suction control; (2) seeding operation control; (3) automatic film cutting control; and (4) film positioning and soil covering control. The control system is flexible and reliable, and can realize the control function of a seeding agricultural implement, and comprehensively realize the automatic control of film cutting, film positioning and soil covering of the whole machine, so that the film cutting, film clamping and film positioning and soil covering work of manpower are replaced. The application improves the automation degree of direct seeding, film cutting and film positioning and soil covering, and can be widely applied to the seeding of soybeans, kidney beans, peanuts and the like.

Description

Technical Field

[0001] This invention relates to the electronic control system technology of intelligent agricultural machinery and equipment, specifically a control method and control system for an automatic film-cutting and soil-covering type chili direct seeding machine. Background Technology

[0002] Chili pepper sowing is divided into direct sowing (referred to as direct seeding) and seedling transplanting. Direct seeding involves using direct seeding machinery to sow seeds in the field, then covering them with soil. This eliminates the need for seedling cultivation and transplanting, saving manpower and improving operational efficiency.

[0003] Currently, chili direct seeding machines have functions such as rotary tillage, sowing, and fertilization. However, the sowing operation is affected by changes in machine speed, easily leading to missed or repeated sowing, which in turn affects seed germination and seedling emergence rates. Furthermore, while the continuous development of sowing and mulching technology has largely solved these problems, manual intervention is still required when the machine needs to turn around in the field. This still necessitates manually tearing the drip irrigation film and tying it to the machine frame. Additionally, when the machine enters a new field, manual assistance is needed to fix the film in place and cover it with soil. These auxiliary tasks are inefficient and labor-intensive. With technological advancements, further improvements in the automation and intelligence of agricultural machinery are urgently needed to meet the aforementioned agricultural operational needs. Summary of the Invention

[0004] In response to the problems raised in the background technology, the purpose of this invention is to provide a control method and system for an automatic film-cutting and soil-covering chili direct seeding machine. Based on information such as the overall machine speed, the speed of the seeding motor, and the speed of the film-cutting drum, the system matches and precisely controls the corresponding speeds of the seeding fan, the seeding motor, and the film-cutting drum. This enables precision seeding, automatic film cutting, and soil covering during automatic film laying and positioning, improving seed germination and seedling emergence rates, and further enhancing the automation and intelligence level of the entire machine.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An automatic film-cutting and soil-covering chili direct seeding machine control method is as follows: After the vehicle starts, the control system collects various analog and digital signals from the vehicle and the onboard seeding equipment to determine whether the vehicle and the onboard seeding equipment are ready for operation; if the vehicle and the onboard seeding equipment are ready, the control system controls the operation according to the following aspects:

[0007] (1) Seed intake control; the control system selects the sowing mode through the agricultural machinery working mode switch. In this mode, before the whole vehicle moves forward, the control system collects the air pressure at the outlet of the sowing fan, the signal of the sowing tray, and the missed sowing situation calculated by the infrared seed port monitoring. The sowing fan speed is coarsely adjusted by the feedforward control method of directly outputting PWM signal. Then, based on the air pressure at the outlet of the sowing fan and the target pressure read from the actual set memory, the control system precisely adjusts the sowing fan speed in the feedback control method, thereby ensuring that there are seeds in both the sowing tray and the seed collection chamber of the sowing machine.

[0008] (2) Sowing operation control; During the whole vehicle sowing operation, the controller of the control system outputs to the N sowing motor drivers through N PWM channels to realize the independent control of each sowing motor. The controller also collects the vehicle speed, the speed of the sowing motor drive shaft, and the position information of the sowing signal disk, and uses a double closed-loop PID control algorithm to control the speed of the sowing motor, thereby controlling the individual sowing to achieve precision sowing operation of the whole vehicle; The sowing operation control also includes automatic obstacle avoidance control, field turning control, field control and special agronomic control;

[0009] (3) Automatic film cutting control: When the vehicle travels to the edge of the field and turns, the control system reads the turning signal of the automatic driving system or the edge mode signal of the remote control, stops the sowing operation, and then collects the rotation speed of the film cutting roller and the position signal of the on-board sowing implement. The hydraulic solenoid valve drives the film clamping hydraulic cylinder to extend, clamping the film device and the film cutting device to descend and compact the film. Then the control system outputs PWM signal and reversing hydraulic valve drive signal to the hydraulic pump motor to control the flow and direction of the hydraulic pump motor, driving the film cutting roller on the film cutting device to rotate forward and realize the film cutting function. Finally, the reversing solenoid valve is driven to make the film clamping hydraulic cylinder retract, clamping the film device and the film cutting device to lift up and complete the film cutting.

[0010] (4) Soil covering control for film laying and positioning; After the film is cut, when the whole machine turns at the edge of the field and enters the new row operation, the control system automatically enters the soil covering mode for film laying and positioning by reading the turning signal of the automatic driving or the field mode signal of the remote control. At this time, the control system collects the rotation speed of the film cutting roller and the position signal of the vehicle-mounted seeding machine. After the vehicle-mounted seeding machine descends to the working position, it drives the film clamping hydraulic cylinder to extend, so that the film clamping device and the film cutting device descend. The control system outputs PWM signal and reversing hydraulic valve drive signal to the hydraulic pump motor. By controlling the flow rate and direction of the hydraulic pump motor, the film cutting roller on the film cutting device is reversed to realize the soil covering for film laying and positioning.

[0011] The specific method for the control system to precisely fine-tune the speed of the seeding fan during seed extraction is as follows: After coarsely adjusting the speed of the seeding fan, the control system reads the seeding disc signal and the infrared seed inlet monitoring status. By acquiring the falling edge signal of the seeding disc, the control system learns the number of signal disc teeth during seed extraction. When two consecutive signal teeth miss a seed, it is determined that there is insufficient power for seed extraction. At this time, the control system automatically increases the current target pressure value in a step-by-step manner, thereby adjusting the duty cycle value output by the control module PO1. The system controls the seeding fan in a closed loop, so that the air pressure at the outlet of the seeding fan reaches the newly set target pressure value. When two consecutive signal teeth repeat a seed, it is determined that there is excess power for seed extraction. At this time, the control system automatically decreases the current target pressure value in a step-by-step manner, thereby adjusting the duty cycle value output by the control module PO1. The system controls the seeding fan in a closed loop, so that the air pressure at the outlet of the seeding fan reaches the newly set target pressure value.

[0012] During sowing operations, the control system independently controls each sowing motor using the following method: The control system collects the drive current value of each sowing motor, the vehicle speed signal, and the rotational speed signal of each sowing motor, and calculates the corresponding vehicle speed and rotational speed; then, based on the vehicle speed and the corresponding target plant spacing and the number of holes in the sowing tray stored in the system memory, it calculates the corresponding target sowing motor shaft rotational speed; the control system then uses a closed-loop PID algorithm to calculate the target drive current value of each sowing motor based on the actual rotational speed signal of each sowing motor shaft and the target rotational speed, which is the outer closed-loop algorithm of the dual closed-loop PID control algorithm; the system then uses the collected actual current value of each sowing motor and the target drive current value of each sowing motor calculated by the outer closed-loop algorithm to calculate the duty cycle of the PWM control signal through the closed-loop PID algorithm. This control PWM signal is output to the N sowing motor drivers through the system's N PWM output modules, thereby precisely controlling the rotation of the N sowing motors and the sowing of the N individual sowing units, thus achieving precision sowing.

[0013] During sowing operations, the field turning control is specifically as follows: after receiving the field turning signal sent by the controller or remote control, the control system stops all sowing motors and outputs zero; the field control is specifically as follows: after receiving the field mode execution signal sent by the controller or remote control, the control system stops all sowing motors and outputs zero; the field turning control and field control ensure that there are no crops at the field edge during direct seeding of chili peppers.

[0014] During sowing operations, the obstacle avoidance control is specifically as follows: After receiving the obstacle avoidance mode execution signal sent by the controller or remote controller, the control system stops all sowing motors and outputs zero; when the control system receives the obstacle avoidance end signal sent by the controller or remote controller, the control system restarts all sowing motors and resumes sowing operations.

[0015] During sowing operations, the specific special agronomic control is as follows: The control system reads the special agronomic operation flag variable calibrated in the controller's memory. When the special agronomic operation flag variable is zero, the control system operates according to the normal sowing operation control mode. When the special agronomic operation flag variable is 1, the control system reads the specific positions of N sowing signal disks respectively. At the same time, the control system outputs a drive signal to the sowing motor with an even number of serial numbers and outputs a signal of zero to the sowing motor with an odd number of serial numbers, causing the sowing motor with an even number of serial numbers to rotate, and the corresponding sowing unit with an even number of serial numbers to sow. At the next moment, the control system outputs a drive signal to the sowing motor with an odd number of serial numbers and outputs a signal of zero to the sowing motor with an even number of serial numbers, causing the sowing motor with an odd number of serial numbers to rotate, and the corresponding sowing unit with an odd number of serial numbers to sow.

[0016] During automatic film cutting, the control system controls the speed of the film cutting roller as follows: The control system drives the film cutting roller at the set target speed. If the speed of the film cutting roller decreases, the control system judges that the film cutting resistance is too large. At this time, the control system automatically controls the film clamping hydraulic cylinder to slowly retract until the film cutting speed is restored to the target speed. Then the control system controls the film clamping hydraulic cylinder to stop moving.

[0017] During the soil covering and positioning of the film, the control system controls the rotation speed of the film cutting roller as follows: The control system drives the film cutting roller at the set target speed. If the rotation speed of the film cutting roller decreases, the control system judges that the soil covering resistance is large. At this time, the control system automatically controls the film clamping hydraulic cylinder to slowly retract until the rotation speed of the film cutting roller returns to the target speed. Then the control system controls the film clamping hydraulic cylinder to stop moving.

[0018] This invention also provides a control system for implementing the control method described above, comprising a controller, a communication module, an output module, sensors for signal acquisition, and actuators for executing controller commands. The sensors include an agricultural implement working mode switch, an implement angle sensor, a pneumatic pressure sensor, a seeding motor shaft speed sensor, a vehicle speed sensor, and a film-cutting roller shaft speed sensor. The actuators include an electric seeding fan, a seeding motor, an agricultural implement lifting / lowering solenoid valve, a hydraulic pump motor solenoid valve, a hydraulic pump motor reversing solenoid valve, and a film-clamping hydraulic solenoid valve. The communication module is a CAN communication module, and the output module includes a PWM output module and a digital output module (DO).

[0019] The beneficial effects of this invention are as follows: The control system proposed in this invention flexibly and reliably realizes the control function of seeding machinery in remote control operation or automatic driving mode; firstly, by combining feedforward control and closed-loop feedback control algorithms, it achieves rapid and precise control of the air pressure of the seeding fan, thereby obtaining a stable pressure for drawing seeds from the seed box and preventing micro-leakage in the pipeline; secondly, based on the pre-calibrated relationship between the vehicle speed and the shaft speed of the seeding motor, the actual shaft speed of the seeding motor is collected, and the corresponding driving parameters of the seeding motor are calculated using a dual closed-loop control algorithm, thereby controlling the seeding motor. It enables precision seeding and fertilization control; simultaneously, the controller reads the turning or obstacle avoidance signals from the automatic driving system or remote control via the CAN bus, and coordinates the control of all seeding motors. When the vehicle is automatically avoiding obstacles or turning at the edge of the field, it stops driving all seeding motors and discontinues seeding in the seed collection chamber. When the vehicle turns and resumes operation, it drives the seeding motors to continue seeding in the seed collection chamber. For special agronomic operation requirements, it combines N seeding signal disks to achieve precise and coordinated control of the rotation of the motors at each of the N individual seeding ports, realizing diamond-shaped seeding between N rows, i.e., no seeding in alternate holes.

[0020] In the control method proposed in this invention, the control system collects the rotation speed of the film-cutting roller and the position of the vehicle-mounted seeding implement, adjusts the speed of the film-cutting roller by controlling the hydraulic pump motor, and ensures that the entire film-cutting device does not jam by adjusting the drive output of the film-clamping hydraulic cylinder, so as to smoothly realize functions such as film clamping, forward rotation film cutting, and reverse rotation soil covering.

[0021] This invention comprehensively automates the entire process of film cutting, field-end film laying, and positioning, replacing manual labor for film cutting, clamping, laying, positioning, and soil covering. While improving the automation level of direct seeding, film cutting, film laying, and soil covering, this invention can also be widely applied to the sowing techniques of soybeans, kidney beans, peanuts, and other crops. Attached Figure Description

[0022] Figure 1 This is a flowchart of the control system of the present invention.

[0023] Figure 2 This is a schematic block diagram of the control system of the present invention. Detailed Implementation

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] like Figure 1-2 As shown, the present invention provides a control method and control system for an automatic film-cutting and soil-covering type chili direct seeding machine.

[0026] Taking a vehicle-mounted seeder with four-way seeding motor drivers as an example, the structure of the control system is as follows: Figure 2As shown, the part within the dashed box represents the controller of the control system itself, while the part outside the dashed box represents the various sensors and actuators designed for the system. The sensors include: implement angle sensor, air pressure sensor, seeding motor shaft speed sensor, vehicle speed sensor, film-cutting roller shaft speed sensor, and agricultural implement working mode switch. The actuators include: film-clamping hydraulic cylinder solenoid valve 1, film-clamping hydraulic cylinder solenoid valve 2, hydraulic pump motor directional solenoid valve 1, hydraulic pump motor directional solenoid valve 2, hydraulic pump motor drive proportional solenoid valve, seeding fan, and seeding motor. The three rectangular boxes on the left side of the dashed box represent the digital signal acquisition module DI, analog signal acquisition module AI, and frequency signal acquisition module PI of this control system. The communication module of this control system is a CAN communication module. This control system includes two types of output modules: PWM output modules PO1~6 and digital output modules DO1~4.

[0027] Based on the aforementioned control system, this invention can perform multiple control functions. For specific control methods, please refer to [reference needed]. Figure 1 The flowchart shown illustrates how, based on the aforementioned control system, the system can determine the operational readiness of the vehicle and the vehicle-mounted seeder, achieve the target seed suction air pressure, enable independent and coordinated seeding of the four individual seeders, and implement automatic film cutting, film laying, and soil covering functions. The following explanation, using a vehicle-mounted seeder with four seeding motor drivers as an example, will first illustrate the main control principles involved in the operation.

[0028] First, the control system reads the signals collected by each sensor through the ports of each signal acquisition module, and reads the status of the agricultural machinery working mode switch through the digital signal acquisition module (DI); the frequency signal acquisition module (PI) collects the signals from the vehicle speed sensor, the seeding motor drive shaft speed sensor, and the film cutting drum speed sensor, and calculates the overall vehicle speed, seeding motor drive shaft speed, and film cutting drum speed through the averaging algorithm of the vehicle controller; the analog signal acquisition module (AI) collects the air pressure sensor at the outlet of the seeding fan and the angle sensor of the vehicle-mounted seeding implement, and obtains the seed suction air pressure and the position value of the vehicle-mounted seeding implement after processing by a low-pass filtering algorithm.

[0029] Secondly, the control system analyzes the agricultural machinery operating mode switch signal value collected by the digital acquisition module (DI) to determine whether the entire vehicle can enter the sowing mode. The control system also collects information from the infrared seed inlets of the seeder via the CAN bus module, supplementing it with air pressure information at the outlet of the seed fan to determine if there is air leakage in the seed suction path, causing the seeder to fail to sow seeds. It can also use the signal from the seeding disc of the individual seeder unit to determine the missed sowing status. Furthermore, the control system collects field operation status information from the unmanned driving controller or the remote control (used in non-unmanned driving mode) via the CAN bus module to assist in determining the sowing motor speed of the individual seeder unit and outputting the control algorithm. When the vehicle-mounted seeder is assembled, each seeding signal disc has seven signal teeth. Six of these signal teeth correspond one-to-one with the six seed collection chambers in the individual seeder unit, meaning one signal tooth corresponds to one seed collection chamber. The seventh signal tooth is multi-toothed and serves as the starting tooth signal for each cycle of the control system's counting. The control system collects the seeding signal disc signal via the frequency module (PI) to determine the position of the seeding disc of the individual seeder unit.

[0030] If the vehicle and its onboard seeding equipment are ready, the control system will operate in the following ways:

[0031] (1) Seed suction control: This is the preliminary work of the sowing operation, that is, the sowing fan sucks the seeds from the seed box to the seed collection chamber of the sowing tray. The control system is mainly responsible for controlling the negative pressure suction of the gas for sucking the seeds. Specifically, when the user presses the sowing mode switch, the control system calculates the PWM duty cycle value output to the PWM output module PO1 based on the air pressure value collected by the analog signal module AI at the outlet of the sowing fan, and outputs the PWM signal to the sowing fan motor driver to coarsely adjust the speed of the sowing fan so that the gas pressure at the outlet of the sowing fan quickly reaches about 25 bar. Based on the air pressure at the outlet of the sowing fan and the target pressure of 30 bar set in the system memory, the control system precisely controls the speed of the sowing fan in the form of feedback control, that is, feedforward control + feedback closed-loop PID control algorithm, controls the speed of the sowing fan, finely adjusts the air pressure value to stabilize at 30 bar, thereby obtaining a stable air pressure for sucking seeds, and thus ensuring that there are seeds in the seed collection chamber of the seed tray of the sowing machine. Meanwhile, the control system reads the seed tray signal through the frequency acquisition module PI and the infrared seed port monitoring information read by the CAN bus module. By acquiring the falling edge signal of the seeding disc, the control system learns the number of signal disc teeth during seeding. When two consecutive signal teeth (i.e., when two consecutive seed collection chambers of three out of four seeding units) miss seeding, it is determined that there is insufficient power to absorb seeds. At this time, the control system automatically increases the current target pressure value in a step-wise manner. In one embodiment of the invention, the step value for increasing the current target pressure value is 5 bar, that is, the control system automatically increases the current target pressure value by 5 bar to 35 bar, thereby adjusting the duty cycle value output by the control module PO1. The system then controls the seeding fan in a closed loop to achieve an air pressure of 35 bar. Conversely, when two consecutive signal teeth (three consecutive seed collection chambers of three out of four seeding units) reseed, it is determined that there is excess power to absorb seeds. At this time, the control system automatically decreases the current target pressure value in a step-wise manner. In one embodiment of the invention, the step value for decreasing the current target pressure value is 3 bar, that is, the control system automatically decreases the current target pressure value by 3 bar to 27 bar, thereby adjusting the duty cycle value output by the control module PO1. The system then controls the seeding fan in a closed loop to achieve an air pressure of 27 bar. bar.

[0032] (2) Sowing Operation Control: The control system uses the analog signal acquisition module AI to read the drive current value of the sowing motor of each of the four sowing units, and uses the frequency signal acquisition module PI to acquire the vehicle speed signal and the rotation speed signal of each sowing motor shaft of the four sowing units to calculate the corresponding vehicle speed and rotation speed. Based on the vehicle speed and the corresponding target plant spacing of 17.8 cm and the number of holes in the seed tray of 6 in the system memory, the corresponding target sowing motor shaft rotation speed is calculated. The control system uses a closed-loop PID algorithm to calculate the target drive current value of each sowing motor according to the actual rotation speed signal of each sowing motor shaft and the target rotation speed. This is the outer closed-loop control of the double closed-loop PID control algorithm. The control system then uses the previously acquired actual current value of each sowing motor and the target current value calculated by the outer closed-loop algorithm to calculate the duty cycle of the PWM control signal through the closed-loop PID algorithm. This control PWM signal is output to the four sowing motor drivers through the four PWM output modules PO2~PO5 of the system, thereby precisely controlling the rotation of the four sowing motors and the sowing of the four sowing units, thus realizing the precision sowing function. When the control system receives a field-end turning operation or field-end mode signal from the unmanned controller or remote control via the CAN communication module, it stops the four seeding motors, outputting a value of zero to ensure that there are no crops at the field edge during direct seeding of chili peppers. Simultaneously, when the control system receives an obstacle avoidance mode signal from the unmanned controller or remote control via the CAN communication module, it stops the four seeding motors, outputting a value of zero, i.e., interrupts seeding. When the machine receives an obstacle avoidance end signal from the unmanned controller or remote control, the control system restarts the four seeding motors, i.e., resumes seeding. This again ensures that there are no crops at the field edge during direct seeding of chili peppers.

[0033] For special agronomic operation requirements, commonly known as the "spurious seedling" sowing method, taking four sowing units as an example, the specifics are as follows: At the same time, in the four sowing units, the even-numbered rows sow seeds from the seed collection chamber, and the sowing motor rotates to release the seeds; the odd-numbered rows' sowing motors stop rotating and do not release seeds. The next time, the reverse occurs: the sowing motors that released seeds in the previous time stop rotating and do not release seeds, while the sowing motors of the other row that did not release seeds in the previous time rotate and release seeds, thus forming intermittent sowing in the holes, achieving "spurious seedling" sowing. This invention provides the following control scheme: The control system reads the special agronomic operation flag variable calibrated in the vehicle controller's memory. When the special agronomic operation flag variable is zero, the control system operates according to the aforementioned normal sowing operation mode. If the special agronomic operation flag variable is 1, the control system reads the specific positions of the four sowing signal disks through the frequency signal PI module. At the same time, the control system outputs drive signals to the PWM output modules PO2 and PO4, causing the corresponding sowing motors to rotate and the corresponding sowing units to release seeds. The drive signals of the PWM output modules PO3 and PO5 are then zero. At the next moment, the control system outputs drive signals to PWM output modules PO3 and PO5, which in turn causes the corresponding seeding motor to rotate and the corresponding seeding unit to sow seeds. The drive signals of PWM output modules PO2 and PO4 are then zero.

[0034] As can be seen from the above-mentioned sowing operation control, the control system adopts a dual-closed-loop PID control method to control the speed of the sowing motor, thereby controlling the individual seeding and achieving the operational requirements of seeding, interrupted sowing, and resumed sowing during normal precision sowing operations and automatic obstacle avoidance. The system uses a combination of self-learning sowing disc signal position and dual-closed-loop PID control of the sowing motor speed to realize special sowing agronomic operations such as "bent seedlings".

[0035] (3) Automatic film cutting control: When the control system receives the field turning operation or field mode from the unmanned driving controller or remote control via the CAN communication module, the control system stops the operation of the four sowing motors and the output value is zero. Then, the control system outputs 1 and 0 to the digital output modules DO3 and DO4 respectively, driving the film clamping solenoid valve 1 and film clamping solenoid valve 2 to actuate, causing the film clamping hydraulic cylinder to extend, causing the film clamping device to tightly clamp the film and keep it stationary. After 5 seconds, the control system outputs 0 to both digital output modules DO3 and DO4. At this time, the film clamping hydraulic cylinder remains stationary. Then, the control system outputs 1 and 0 to the digital output modules DO1 and DO2 respectively, driving the pump motor direction solenoid valve, which, in conjunction with the hydraulic system, causes the hydraulic pump motor to rotate clockwise. Simultaneously, the control system acquires the film-cutting roller shaft speed through the frequency signal acquisition module PI and compares it with the film-cutting target speed of 230 r / min calibrated in the control system's memory. This speed is used as input for the feedback closed-loop PID control algorithm to calculate the PWM duty cycle value of the hydraulic proportional valve driven by the PWM output module PO6. Combined with the hydraulic system motor driving the film-cutting roller shaft to rotate forward and reach a speed of 230 r / min, the control system controls the film-cutting device to achieve the function of automatically cutting film and drip irrigation tape for 20 seconds. After that, the control system immediately outputs 0 to the digital output modules DO1 and DO2 and the PWM output module PO6 respectively, and the entire device remains stationary. The system completes the film-cutting and drip irrigation tape cutting operations. During the 20-second film cutting period, if the control system monitors the changes in the film cutting drum speed, and the speed drops below 110 r / min, the system will determine that the film cutting has encountered significant resistance, such as hard rocks in the soil. The control system will automatically output 0 and 1 to digital output modules DO3 and DO4 respectively, driving the film clamping solenoid valves 1 and 2 to retract the film clamping hydraulic cylinder. This continues until the film cutting speed recovers to above 200 r / min, at which point the control system outputs 0 to digital output modules DO3 and DO4, and the film clamping hydraulic cylinder stops operating. After completing the 20-second film cutting operation, the control system outputs 0 and 1 to digital output modules DO3 and DO4 respectively, driving the film clamping solenoid valves 1 and 2 to retract the film clamping hydraulic cylinder for 10 seconds to its original position. At this point, the film clamping device tightly holds the mulch film. Afterward, the control system automatically raises the agricultural machinery and sounds a horn as a warning. The unmanned control controller or remote control then begins operating the entire machine to turn at the edge of the field.

[0036] (4) Control of soil covering for film laying and positioning: After the machine finishes cutting the film, the unmanned driving controller or remote control starts operating the machine to turn at the head of the field. When the machine enters a new row of operation, the control system reads the turning signal of the automatic driving or the head mode signal of the remote control through the CAN communication module, and collects the film cutting roller speed value through the frequency signal acquisition module PI and the seeder implement angle sensor value through the analog signal acquisition module AI. After the working implement descends to the implement angle value of 160 degrees, which is the working position of the implement, the control system outputs 1 and 0 to the digital output modules DO3 and DO4 respectively, driving the film clamping solenoid valve 1 and film clamping solenoid valve 2 to act, so that the film clamping hydraulic cylinder extends, causing the film clamping device to tightly clamp the film and keep it stationary. After 5 seconds, the control system outputs 0 to both digital output modules DO3 and DO4. At this time, the film clamping hydraulic cylinder remains stationary. Then, the control system outputs 0 and 1 to the digital output modules DO1 and DO2 respectively, driving the pump motor direction solenoid valve, which, in conjunction with the hydraulic system, makes the hydraulic pump motor rotate counterclockwise. Simultaneously, the control system acquires the rotational speed of the film-cutting roller shaft through the frequency signal acquisition module PI and compares it with the target film-cutting speed of 300 r / min calibrated in the control system's memory. This is used as input for the feedback closed-loop PID control algorithm to calculate the PWM duty cycle value of the hydraulic proportional valve driven by the PWM output module PO6. Combined with the hydraulic system motor driving the film-cutting roller shaft to rotate forward and reach a speed of 300 r / min, the control system controls the film-cutting device to achieve the function of automatic soil covering for 20 seconds. After that, the control system immediately outputs 0 to the digital output modules DO1 and DO2 and the PWM output module PO6 respectively, and the entire device remains stationary. The system completes the soil covering operation for film laying and positioning. Similar to the description in section 0019, during the 20-second soil covering period, if the control system monitors changes in the cutting roller speed, and if the speed drops below 150 r / min, the system will determine that the soil covering has encountered significant resistance, such as hard rocks in the soil. The control system will automatically output 0 and 1 to digital output modules DO3 and DO4 respectively, driving the clamping solenoid valves 1 and 2 to retract the clamping hydraulic cylinder. This continues until the cutting speed recovers to above 250 r / min, at which point the control system outputs 0 to digital output modules DO3 and DO4, and the clamping hydraulic cylinder stops operating. After completing the 20-second soil covering operation, the control system sounds a horn to indicate completion and sends information about the completion of the cutting and soil covering operation to the unmanned driving controller via the CAN bus module. Afterwards, the unmanned driving controller or the user can operate the remote control to begin sowing operations on the new plot.

[0037] The direct seeding machine described in the above embodiments is a chili pepper direct seeding machine. The control method and control system described in this invention can also be applied to other types of direct seeding machines, such as rice direct seeding machines and corn direct seeding machines.

[0038] The parts of this invention not described in detail are prior art.

Claims

1. A control method for an automatic film-cutting and soil-covering type chili direct seeding machine, characterized in that: After the vehicle starts, the control system collects various analog and digital signals from the vehicle and the onboard seeder to determine whether the vehicle and the onboard seeder are ready for operation. If the vehicle and the onboard seeder are ready, the control system will control them in the following ways: (1) Seed intake control; the control system selects the sowing mode through the agricultural machinery working mode switch. In this mode, the control system collects the air pressure at the outlet of the sowing fan, the signal of the sowing tray, and the missed sowing situation calculated by the infrared seed port monitoring. The sowing fan speed is coarsely adjusted by the feedforward control method of directly outputting PWM signal. Then, based on the air pressure at the outlet of the sowing fan and the target pressure read from the actual set memory, the control system precisely adjusts the sowing fan speed in the feedback control method to ensure that there are seeds in both the sowing tray and the seed collection chamber of the sowing machine. (2) Sowing operation control; During the whole vehicle sowing operation, the controller of the control system outputs to the N sowing motor drivers through N PWM channels to realize the independent control of each sowing motor. The controller also collects the vehicle speed, the speed of the sowing motor drive shaft, and the position information of the sowing signal disk, and uses a double closed-loop PID control algorithm to control the speed of the sowing motor, thereby controlling the individual sowing to achieve precision sowing operation of the whole vehicle; The sowing operation control also includes automatic obstacle avoidance control, field turning control, field control and special agronomic control; (3) Automatic film cutting control: When the vehicle travels to the edge of the field and turns, the control system reads the turning signal of the automatic driving system or the edge mode signal of the remote control, stops the sowing operation, and then collects the rotation speed of the film cutting roller and the position signal of the on-board sowing implement. The hydraulic solenoid valve drives the film clamping hydraulic cylinder to extend, clamping the film device and the film cutting device to descend and compact the film. Then the control system outputs PWM signal and reversing hydraulic valve drive signal to the hydraulic pump motor to control the flow and direction of the hydraulic pump motor, driving the film cutting roller on the film cutting device to rotate forward and realize the film cutting function. Finally, the reversing solenoid valve is driven to make the film clamping hydraulic cylinder retract, clamping the film device and the film cutting device to lift up and complete the film cutting. (4) Soil covering control for film laying and positioning: After the film is cut, when the vehicle turns at the edge of the field and enters the new row operation, the control system automatically enters the soil covering mode for film laying and positioning by reading the turning signal of the automatic driving or the field mode signal of the remote control. At this time, the control system collects the rotation speed of the film cutting roller and the position signal of the vehicle-mounted seeding machine. After the vehicle-mounted seeding machine descends to the working position, it drives the film clamping hydraulic cylinder to extend, clamps the film device and the film cutting device to descend. The control system outputs PWM signal and reversing hydraulic valve drive signal to the hydraulic pump motor. By controlling the flow and direction of the hydraulic pump motor, the film cutting roller on the film cutting device is reversed to achieve soil covering for film laying and positioning. During sowing operations, the specific special agronomic control is as follows: The control system reads the special agronomic operation flag variable calibrated in the controller's memory. When the special agronomic operation flag variable is zero, the control system operates according to the normal sowing operation mode. When the special agronomic operation flag variable is 1, the control system reads the specific positions of N sowing signal disks respectively. At the same time, the control system outputs a drive signal to the sowing motor with an even number of serial numbers and outputs a signal of zero to the sowing motor with an odd number of serial numbers, causing the sowing motor with an even number of serial numbers to rotate, and the corresponding sowing unit with an even number of serial numbers to sow. At the next moment, the control system outputs a drive signal to the sowing motor with an odd number of serial numbers and outputs a signal of zero to the sowing motor with an even number of serial numbers, causing the sowing motor with an odd number of serial numbers to rotate, and the corresponding sowing unit with an odd number of serial numbers to sow.

2. The control method for an automatic film-cutting and soil-covering type chili direct seeding machine according to claim 1, characterized in that: The specific method for the control system to precisely fine-tune the speed of the seeding fan during seed extraction is as follows: After coarsely adjusting the speed of the seeding fan, the control system reads the seeding disc signal and the infrared seed inlet monitoring status. By acquiring the falling edge signal of the seeding disc, the control system learns the number of signal disc teeth during seed extraction. When two consecutive signal teeth miss a seed, it is determined that there is insufficient power for seed extraction. At this time, the control system automatically increases the current target pressure value in a step-by-step manner, thereby adjusting the duty cycle value output by the control module PO1. The system controls the seeding fan in a closed loop, so that the air pressure at the outlet of the seeding fan reaches the newly set target pressure value. When two consecutive signal teeth repeat a seed, it is determined that there is excess power for seed extraction. At this time, the control system automatically decreases the current target pressure value in a step-by-step manner, thereby adjusting the duty cycle value output by the control module PO1. The system controls the seeding fan in a closed loop, so that the air pressure at the outlet of the seeding fan reaches the newly set target pressure value.

3. The control method for an automatic film-cutting and soil-covering type chili direct seeding machine according to claim 1, characterized in that: During sowing operations, the control system independently controls each sowing motor using the following method: The control system collects the drive current value of each sowing motor, the vehicle speed signal, and the rotational speed signal of each sowing motor, and calculates the corresponding vehicle speed and rotational speed; then, based on the vehicle speed and the corresponding target plant spacing and the number of holes in the sowing tray stored in the system memory, it calculates the corresponding target sowing motor rotational speed; the control system then uses a closed-loop PID algorithm to calculate the target drive current value of each sowing motor based on the actual rotational speed signal and the target rotational speed of each sowing motor. This is the outer closed-loop algorithm of the dual closed-loop PID control algorithm. The system then uses the actual current value of each seeding motor and the target current value of each seeding motor calculated by the external closed-loop algorithm to calculate the duty cycle of the PWM control signal through the closed-loop PID algorithm. This control PWM signal is then output to the N seeding motor drivers through the N PWM output modules of the system, thereby precisely controlling the rotation of the N seeding motors and the sowing of the N seeding units, thus realizing the precision sowing function.

4. The control method for an automatic film-cutting and soil-covering type chili direct seeding machine according to claim 1, characterized in that: During sowing operations, the field turning control is specifically as follows: after receiving the field turning signal sent by the controller or remote control, the control system stops all sowing motors and outputs zero; the field control is specifically as follows: after receiving the field mode execution signal sent by the controller or remote control, the control system stops all sowing motors and outputs zero; the field turning control and field control ensure that there are no crops at the field edge during direct seeding of chili peppers.

5. The control method for an automatic film-cutting and soil-covering type chili direct seeding machine according to claim 1, characterized in that: During sowing operations, the obstacle avoidance control is specifically as follows: After receiving the obstacle avoidance mode execution signal sent by the controller or remote controller, the control system stops all sowing motors and outputs zero; when the control system receives the obstacle avoidance end signal sent by the controller or remote controller, the control system restarts all sowing motors and resumes sowing operations.

6. The control method for an automatic film-cutting and soil-covering type chili direct seeding machine according to claim 1, characterized in that: During automatic film cutting, the control system controls the speed of the film cutting roller as follows: The control system drives the film cutting roller at the set target speed. If the speed of the film cutting roller decreases, the control system judges that the film cutting resistance is too large. At this time, the control system automatically controls the film clamping hydraulic cylinder to retract until the film cutting speed is restored to the target speed. Then the control system controls the film clamping hydraulic cylinder to stop moving.

7. The control method for an automatic film-cutting and soil-covering type chili direct seeding machine according to claim 1, characterized in that: During the soil covering and positioning of the film, the control system controls the rotation speed of the film cutting roller as follows: The control system drives the film cutting roller at the set target speed. If the rotation speed of the film cutting roller decreases, the control system judges that the soil covering resistance is large. At this time, the control system automatically controls the film clamping hydraulic cylinder to retract until the rotation speed of the film cutting roller returns to the target speed. Then the control system controls the film clamping hydraulic cylinder to stop moving.

8. A control system for implementing the control method as described in any one of claims 1-7, comprising a controller, a communication module, an output module, a sensor for signal acquisition, and an actuator for executing controller commands, characterized in that: The sensors include an agricultural implement working mode switch, an implement angle sensor, an air pressure sensor, a seeding motor shaft speed sensor, a vehicle speed sensor, and a film-cutting drum shaft speed sensor; the actuators include a seeding fan, a seeding motor, an agricultural implement lifting / lowering solenoid valve, a hydraulic pump motor solenoid valve, a hydraulic pump motor reversing solenoid valve, and a film-clamping hydraulic solenoid valve; the communication module is a CAN communication module, and the output modules include a PWM output module and a digital output module DO.

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