A control method for automatic leveling of a rice combine harvester chassis

Abstract

The application provides a control method for controlling the on-off time of an electromagnetic valve based on a fuzzy PID algorithm, which is used for realizing the automatic leveling of a rice combine harvester chassis. The method is suitable for the field of intelligent agricultural machinery equipment. The control process is as follows: when the sensor detects that the chassis plane is not in a horizontal state, the electronic control unit (ECU) calculates the leg lifting amount required to make the chassis plane horizontal by using the fuzzy PID algorithm. Then, the leg lifting amount is converted into the extension amount of the hydraulic cylinder, and the extension amount is converted into the energization time of the electromagnetic valve. The sensor continuously provides data to correct the control time, so as to realize the closed-loop automatic control effect. Compared with the traditional fuzzy PID control flow method, the advantage of the application lies in that the flow is not required to be controlled by a proportional valve or other flow control valve, the response speed is faster, and the application is suitable for scenes with high response speed requirements.

Description

Technical Field

[0001] This invention relates to the field of intelligent agricultural machinery and equipment, and more specifically, to a control method for automatic leveling of the chassis of a rice combine harvester. Background Technology

[0002] In modern agriculture, the efficiency and quality of combine harvesters in paddy fields are crucial. However, due to the undulating terrain and varying soil looseness in paddy fields, the harvester chassis often experiences bumps and swaying, which undoubtedly affects the operational results and quality. Traditional chassis control methods mainly rely on proportional-integral-derivative (PID) controllers for leveling. Although PID controllers are simple and easy to use, their fixed control parameters result in slow response to the complex and changing working environment of paddy fields, and their control accuracy is not ideal, thus failing to meet the high requirements of modern agriculture for operational efficiency and quality. Against this backdrop, fuzzy incremental PID control algorithms have emerged.

[0003] Compared to traditional PID controllers, the main advantage of fuzzy PID controllers lies in their ability to dynamically adjust control parameters. By introducing fuzzy logic, fuzzy incremental PID controllers can perform fuzzy inference on the input error and the rate of change of error, outputting the increment of PID parameters, thus making the controller more adaptable to changing working environments. The introduction of this algorithm greatly improves the response speed and accuracy of the chassis automatic leveling, optimizes chassis stability, and consequently improves the efficiency and quality of combine harvesters in paddy fields. Summary of the Invention

[0004] This invention provides a control method for automatic leveling of the chassis of a rice combine harvester, which has significant advantages in real-time monitoring and adjustment of the chassis balance. The controller structure includes the following components: a nine-axis digital gyroscope attitude sensor, a hydraulic cylinder displacement sensor, a 32-bit microcontroller, an analog-to-digital converter module, a hydraulic cylinder drive module, a 12V to 5V step-down module, a 12V to 24V step-up module, independent buttons, a level conversion module, and a 5V to 3.3V interchange module.

[0005] The following steps are taken during the control process:

[0006] S1: Real-time acquisition of chassis and hydraulic cylinder data. First, a nine-axis digital gyroscope attitude sensor and a hydraulic cylinder displacement sensor monitor the chassis's left and right tilt angles and the hydraulic cylinder's extension in real time. These two sensors provide accurate real-time data input by precisely detecting the chassis's real-time status. Simultaneously, this data is connected to a 32-bit microcontroller via serial communication and an analog-to-digital converter module, enabling fast and accurate data processing and calculation.

[0007] S2: Calculate chassis deviation. After obtaining the left and right tilt angle data of the chassis and the extension data of the hydraulic cylinder, the tilt angle error calculation module of the 32-bit microcontroller is used to calculate the deviation of the chassis relative to the horizontal state and the extension and retraction of the hydraulic cylinder. Through this step, the current state of the chassis can be accurately understood, and it can be determined whether adjustments are needed.

[0008] S3: Application of Fuzzy Incremental PID Control Algorithm. Based on the calculated deviation and hydraulic cylinder extension / retraction, the incremental PID calculation module employs a fuzzy incremental PID control algorithm to calculate the control signal for automatic leveling of the chassis in the left and right directions. Unlike traditional PID controllers, the fuzzy incremental PID controller first performs fuzzy inference based on the input angle, outputting increments in the proportional (ΔKp), integral (ΔKi), and derivative (ΔKd) coefficients. These increments are then applied to the incremental PID controller, and the calculation formula is: Control signal = (Kp + ΔKp) × Δe + (Ki + ΔKi) × ∑e + (Kd + ΔKd) × Δ(de(θ) / dt). This algorithm can automatically adapt to changes in system parameters, improving system performance and stability.

[0009] S4: Converting the control signal into actual control operation. The control signal from the fuzzy incremental PID controller is converted into the on / off time signal of the solenoid valve, which is powered by the hydraulic cylinder drive module and the 12V to 24V boost module, thereby achieving precise left and right leveling of the chassis. During this process, a level conversion module and a 5V to 3.3V interchange module are used to appropriately adjust the power supply voltage to ensure that the control signal of the hydraulic drive module is boosted to a 5V level for normal operation.

[0010] Traditional PID controllers, while widely used in many applications, have a significant drawback: they cannot effectively handle system nonlinearity and uncertainty. In particular, when system parameters change, the PID controller parameters often need to be readjusted; otherwise, system performance may degrade.

[0011] The present invention has the following beneficial effects:

[0012] The fuzzy incremental PID controller used in this invention can significantly improve the performance and stability of the system because it can automatically adapt to changes in system parameters.

[0013] The control method of the present invention can realize automatic leveling of the chassis, thereby improving work efficiency and work quality.

[0014] This invention provides an automatic leveling control method for the chassis of a rice combine harvester that features high precision, fast response, and simple operation. Attached image description:

[0015] Figure 1 This is a flowchart of the leveling control system of the present invention.

[0016] Figure 2 This is the electrical schematic diagram of the present invention.

[0017] Figure 3 This is a flowchart of the control method of the present invention. Specific implementation methods:

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments. Figure 1 , Figure 2 The present invention provides a control system for automatic leveling of the chassis of a rice combine harvester, comprising a controller including: a nine-axis digital gyroscope attitude sensor, a hydraulic cylinder displacement sensor, a 32-bit microcontroller, an analog-to-digital converter module, a hydraulic cylinder drive module, a 12V to 5V step-down module, a 12V to 24V step-up module, an independent button, a level conversion module, and a 5V to 3.3V interchange module. The power supply is connected to the level conversion module and the 5V to 3.3V interchange module via the 5V step-down module.

[0019] The power supply is a 12V battery. An external OLED display is connected to the microcontroller to display real-time angle data. The power supply is connected to a 24V boost module and a 5V buck module to power the solenoid valve drive module and the 5V to 3.3V converter module, respectively. The 5V to 3.3V converter module then powers the microcontroller. The tilt sensor is powered by the microcontroller, and its data transmission port is connected to the microcontroller's serial communication port. The hydraulic cylinder displacement sensor is powered by the microcontroller, and an analog-to-digital converter module converts the analog signal into a digital signal, which is then input to the microcontroller via IIC communication.

[0020] The nine-axis digital gyroscope attitude sensor is mounted on the center surface of the chassis, and the hydraulic cylinder displacement sensor is mounted next to the hydraulic rod and linked with the hydraulic cylinder.

[0021] The chassis can be tilted to the left or right by controlling the lifting and lowering of two hydraulic cylinders through four independent buttons.

[0022] To level the chassis, first use the independent button to tilt it to the left or right. Then, press the mode switch button to put the controller into automatic leveling mode. At this time, the tilt angle and the extension of the hydraulic rod will be input into the 32-bit microcontroller.

[0023] Entering the built-in program of the 32-bit microcontroller, the fuzzy control calculation is first performed by angle to obtain the increment of PID parameters. The increment is added to the PID parameters to obtain the final PID parameters. Then, the error (E) and the rate of change of error (EC) are used as inputs to the PID to calculate the PID output. The PID output is then used to control the increment of the hydraulic cylinder to achieve automatic leveling control.

[0024] Example: A control method for automatic leveling of the chassis of a rice combine harvester, comprising the following steps:

[0025] Step 1: First, start the rice combine harvester and ensure that all components in the system are in normal working order. This includes, but is not limited to, the nine-axis digital gyroscope attitude sensor, the hydraulic cylinder displacement sensor, the 32-bit microcontroller, and the hydraulic cylinder drive module.

[0026] Step Two: Next, select the system's operating mode. The system has two operating modes: manual leveling mode and automatic leveling mode. In manual mode, the operator can directly control the lifting and lowering of the hydraulic cylinders using four independent buttons to tilt the chassis left or right. In automatic mode, the tilt angle and hydraulic cylinder displacement data are sent to a 32-bit microcontroller for processing.

[0027] Step 3: In automatic mode, once the system receives data on chassis tilt, the microcontroller will begin running its built-in fuzzy control program. This program calculates the chassis tilt angle and the displacement of the hydraulic cylinder. This process involves an advanced fuzzy incremental PID control algorithm, which accurately calculates the extension and retraction of the hydraulic cylinder.

[0028] Step 4: After calculating the extension and retraction of the hydraulic cylinder, the control system will send a signal to the hydraulic cylinder drive module to make the hydraulic cylinder perform the corresponding extension and retraction action, thereby realizing the automatic leveling of the chassis.

[0029] Step 5: During the leveling process, the system will continuously monitor the chassis tilt status and feed the data back to the control system. If the system detects that the chassis tilt has been corrected, the control system will stop sending signals to the hydraulic cylinder drive module. Conversely, if the system detects that the chassis is still tilted, the control system will repeat the leveling process until the chassis reaches the preset level.

[0030] Step Six: To allow operators to understand the real-time tilt status of the chassis, the system is also equipped with an OLED display screen. This screen will display the real-time tilt angle of the chassis, allowing operators to intuitively understand the current status of the chassis.

[0031] Step 7: Finally, if operators need to switch working modes, they can do so at any time using a separate mode switching button, switching from automatic mode to manual mode, or vice versa.

[0032] It should be noted that the above description is only an example of a specific implementation method. For those skilled in the art, other improvements and modifications can be made without departing from the principle of the present invention to adapt to different application scenarios.

[0033] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A control method for automatic leveling of the chassis of a rice combine harvester, characterized by: The controller, control module, and control method are described. The controller includes a nine-axis digital gyroscope attitude sensor, a hydraulic cylinder displacement sensor, a microcontroller, and a hydraulic cylinder drive module. The nine-axis digital gyroscope attitude sensor is connected to a 32-bit microcontroller, and the hydraulic cylinder displacement sensor is connected to an analog-to-digital converter module. The microcontroller is connected to the microcontroller through the analog-to-digital converter module and a communication output. It also includes a 12V to 5V step-down module, a 12V to 24V step-up module, an independent button, a level conversion module, and a 5V to 3.3V interchange module. The power supply is connected to the level conversion module and the 5V to 3.3V interchange module via the 5V step-down module. The power supply is a 12V battery. The microcontroller is connected to an external OLED display to display real-time angle data. The power supply is connected to a 24V boost module and a 5V buck module to power the solenoid valve drive module and the 5V to 3.3V module, respectively. The 5V to 3.3V module is connected to the microcontroller to power the microcontroller. The tilt sensor is powered by the microcontroller and its data transmission port is connected to the microcontroller's serial port for communication. The hydraulic cylinder displacement sensor is powered by the microcontroller and uses an analog-to-digital converter module to convert the analog signal into a digital signal, which is then input to the microcontroller via IIC communication. The nine-axis digital gyroscope attitude sensor is mounted on the center surface of the chassis, and the hydraulic cylinder displacement sensor is mounted next to the hydraulic rod and linked with the hydraulic cylinder. The chassis can be tilted to the left or right by controlling the lifting and lowering of two hydraulic cylinders through four independent buttons. During leveling, first use the independent button to tilt the chassis to the left or right. Then press the mode switch button to put the controller into automatic leveling mode. The tilt angle and the extension of the hydraulic rod are input into the 32-bit microcontroller. The control module includes a tilt angle error calculation module, a PID parameter fuzzy control module, an incremental PID calculation module, and a control signal conversion module. The tilt angle error calculation module is used to calculate the error value of the left and right tilt angle of the chassis. a) The PID parameter fuzzy control module controls the magnitude of the PID parameter increment by the size of the angle, thereby changing the overall response time of the system; b) Incremental PID calculation module, based on the calculated tilt angle error value, calculates the incremental PID control signal for automatic leveling of the chassis in the left and right directions; c) Control signal conversion module, which converts incremental PID control signal into solenoid valve on / off time signal to achieve precise leveling of the chassis in the left and right directions; The control method is as follows: S1: The left and right tilt angles of the chassis and the extension of the hydraulic cylinder are obtained in real time through tilt sensors and hydraulic cylinder extension sensors. S2: Based on the acquired data of the chassis tilt angle and hydraulic cylinder extension, calculate the deviation of the chassis relative to the horizontal state and the extension / retraction value of the hydraulic cylinder. S3: Applying a fuzzy incremental PID control algorithm, the control signal for automatic leveling of the chassis in the left and right directions is calculated based on the deviation and the extension and retraction of the hydraulic cylinder; the fuzzy logic controller first performs fuzzy inference based on the input angle and outputs the increments of the proportional (ΔKp), integral (ΔKi) and derivative (ΔKd) coefficients; S4: These increments are then applied to the incremental PID controller, and the calculation formula is as follows: Control signal = (Kp + ΔKp) × Δe + (Ki + ΔKi) × ∑e + (Kd + ΔKd) × Δ(de(θ) / dt) S5: Converts the control signal of the fuzzy incremental PID controller into the on / off time of the solenoid valve, thereby achieving precise left and right leveling of the chassis. During the leveling process, the tilt status of the chassis is continuously monitored and the data is fed back to the control system. If the tilt status of the chassis has been corrected, the signal sent to the hydraulic cylinder drive module is stopped. If the chassis is still tilted, the leveling process is repeated until the chassis reaches the preset level.

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