Agricultural machinery control method and device, electronic equipment and storage medium

Abstract

The invention provides an agricultural machinery control method and device, electronic equipment and a storage medium, relates to the technical field of agricultural machinery and is applied to machines and tools, and the method comprises the steps that target compaction density corresponding to forage during bundling is received from a tractor; according to the target compaction density and forage parameters corresponding to the type of the forage to be bundled, calculating a target pressure value of the forage during bundling; the actual compaction density of the forage during bundling is obtained, and the actual pressure value is determined according to the actual compaction density; according to the actual pressure value and the target pressure value, the opening degree of an electromagnetic valve is adjusted so as to change the actual pressure value applied when the forage is bundled; when it is detected that the actual pressure value reaches the pressure limit value and the opening degree of the electromagnetic valve still needs to be adjusted, a vehicle speed control signal is generated and sent to the tractor according to the actual pressure value and the target pressure value so as to control the tractor to conduct speed adjustment and grass feeding amount adjustment. By means of the device, the tractor speed is reversely controlled, the grass feeding amount is adjusted, and the grass bundling efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of agricultural machinery. Specifically, the present application relates to a control method for agricultural machinery, a control device, an electronic device, and a storage medium. Background Art

[0002] At present, tractors often work in cooperation with supporting implements, and there are mutual control requirements in the operation. For example, when using a large square bale, the vehicle speed needs to be adjusted according to the forage feeding amount and an emergency stop is required when the grass is blocked. However, currently, direct communication between tractors and implements is usually not possible, or data is only transmitted relying on the ISOBUS communication protocol (ISO 11783 - Agricultural and Forestry Tractors and Machinery - Control and Communication Data Network), but this protocol cannot achieve the control of the tractor by the implement.

[0003] The existing technical solutions have the following problems: First, the traditional vehicle speed control method uses a preset fixed vehicle speed for operation, which cannot be adjusted in real time according to the feeding amount, resulting in a high risk of grass blocking in the pre - pressing chamber and low efficiency; Second, under the one - way control mechanism, the implement can only send simple instructions to the tractor, lacking two - way authentication, and there are security risks such as unauthorized device access. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide a control method for agricultural machinery, a control device, an electronic device, and a storage medium to overcome at least one of the above - mentioned defects.

[0005] In a first aspect, an embodiment of the present application provides a control method for agricultural machinery. The method includes: receiving, from a tractor, a target compaction density corresponding to forage during baling; calculating a target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; obtaining the actual compaction density of the forage during baling, and determining an actual pressure value according to the actual compaction density; adjusting the solenoid valve opening degree according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling; when it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening degree still needs to be adjusted, generating and sending a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value to control the tractor to adjust the speed and adjust the forage feeding amount. In an alternative embodiment of the present application, the vehicle speed control signal includes a first vehicle speed control signal and a second vehicle speed control signal. Wherein, the vehicle speed control signal is determined by the following method: when it is detected that the actual pressure value reaches the pressure limit value and the solenoid valve opening still needs to be adjusted, it is judged whether the actual pressure value is greater than the target pressure value; if the actual pressure value is greater than the target pressure value, a first vehicle speed control signal is sent to the tractor to control the tractor to decelerate and reduce the amount of grass entering the implement; if the actual pressure value is less than the target pressure value, a second vehicle speed control signal is sent to the tractor to control the tractor to accelerate and increase the amount of grass entering the implement.

[0006] In an alternative embodiment of the present application, adjusting the opening of the solenoid valve according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling includes: judging whether the actual pressure value is greater than the target pressure value; if the actual pressure value is greater than the target pressure value, controlling the opening of the solenoid valve to increase, so as to control the increase of the hydraulic oil flow in the density oil cylinder, push the compaction plate in the piston chamber, increase the pressure applied to the forage. The solenoid valve is connected to the oil inlet and oil return port of the density oil cylinder through an oil pipe to control the inlet and outlet of the hydraulic oil. The piston rod of the density oil cylinder extends into the piston chamber and is connected to the compaction plate to push the compaction plate to move. The forage is placed in the piston chamber, and the compaction plate applies pressure to the forage when moving in the piston chamber; if the actual pressure value is not greater than the target pressure value, controlling the opening of the solenoid valve to decrease, so as to control the reduction of the hydraulic oil flow in the density oil cylinder, not push the compaction plate in the piston chamber, and reduce the pressure applied to the forage.

[0007] In an alternative embodiment of the present application, the method further includes: when the tractor and the implement are started, sending the first version information to the tractor, receiving the second version information fed back by the tractor, and establishing a connection with the tractor according to the version number corresponding to the second version information; after receiving the authorization signal, using digital certificates and encryption mechanisms for two-way authentication of the tractor and the implement to connect the authorized tractor equipment to the implement.

[0008] In an alternative embodiment of the present application, the method further includes: after the implement is connected to the tractor, sending a tractor vehicle speed control function signal to the tractor and receiving the feedback signal of the tractor. The tractor vehicle speed control function signal is used to represent that the implement sends a function allocation message to the tractor, requesting to exclusively occupy the tractor speed control function; when it is detected that the feedback signal represents an authorization signal from the tractor for the implement to exclusively occupy the tractor speed, sending a speed control signal to the tractor to control the adjustment of the tractor speed.

[0009] In an alternative embodiment of the present application, two-way authentication is performed in the following manner: after the implement establishes a connection with the tractor, a status bit is sent to the tractor, and the status bit is used to represent the first authentication type of the implement; the status information of the tractor is received, and the second authentication type of the tractor is determined; according to the first authentication type and the second authentication type, the target authentication type is determined; when it is detected that the target authentication type indicates lightweight authentication, a first random challenge code is generated, the second random challenge code generated by the tractor is received, a shared key is generated, and a first implement response value is calculated according to the second random challenge code and the shared key; the first implement response value is sent to the tractor, and a first authentication result is received, where the first authentication result is determined by the tractor according to the first tractor response value and the first implement response value, and the first tractor response value is generated according to the shared key and the first random challenge code.

[0010] In an alternative embodiment of the present application, the method further includes: when it is detected that the target authentication type indicates full authentication, a certificate request is sent to the tractor, and the digital certificate of the tractor is obtained; it is determined whether the tractor meets the certificate authentication conditions, where the authentication conditions are used to represent that the received digital certificate does not exist in the local certificate revocation list, the certificate chain is valid, the certificate classification identifier in the digital certificate is consistent with the preset certificate classification identifier, and the field for transmitting information is consistent with the corresponding field in the tractor production certificate; if the tractor does not meet the certificate authentication conditions, an authentication failure signal is sent to the tractor; if the tractor meets the certificate authentication conditions, a certificate authentication success signal is sent to the tractor, a first random challenge code is generated, and the second random challenge code generated by the tractor is received; a shared key is generated according to the first random challenge code and the second random challenge code; the shared key is split into a first independent key and a second independent key, and the first independent key is sent to the tractor, and the second independent key sent by the tractor is received; a second implement response value is calculated according to the second random challenge code and the second independent key; the second implement response value is sent to the tractor, and a second authentication result is received, where the second authentication result is determined by the tractor according to the second tractor response value and the second implement response value, and the second tractor response value is generated according to the first independent key and the first random challenge code.

[0011] Second aspect, the embodiments of the present application further provide an agricultural machinery control device, which includes: a target compaction density receiving module, configured to receive the target compaction density corresponding to the forage during baling from a tractor; a target pressure value calculating module, configured to calculate the target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; an actual pressure value determining module, configured to obtain the actual compaction density of the forage during baling and determine the actual pressure value according to the actual compaction density; an adjustment module, configured to adjust the solenoid valve opening according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling; a vehicle speed control signal sending module, configured to generate and send a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value when it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening still needs to be adjusted, so as to control the tractor to perform speed adjustment and adjust the forage intake amount. Third aspect, the embodiments of the present application further provide an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus. When the machine-readable instructions are executed by the processor, the steps of the above-mentioned method are executed.

[0012] Fourth aspect, the embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, the steps of the above-mentioned method are executed.

[0013] The agricultural machinery control method, control device, electronic device, and storage medium provided by the embodiments of the present application receive the target compaction density corresponding to the forage during baling from a tractor; calculate the target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; obtain the actual compaction density of the forage during baling and determine the actual pressure value according to the actual compaction density; adjust the solenoid valve opening according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling; when it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening still needs to be adjusted, generate and send a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value, so as to control the tractor to perform speed adjustment and adjust the forage intake amount. Through the present application, a vehicle speed control signal is generated and sent to the tractor to realize reverse control of the vehicle speed and adjustment of the forage intake amount of the implement, thereby improving the baling efficiency and quality.

[0014] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically gives preferred embodiments and cooperates with the accompanying drawings for detailed description as follows. Description of the Drawings

[0015] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a flowchart of the agricultural machinery control method provided by the embodiments of the present application; Figure 2 It is a flowchart of determining the vehicle speed control signal provided by the embodiments of the present application; Figure 3 It is one of the flowcharts for two-way authentication between the tractor and the implement; Figure 4 It is the second flowchart for two-way authentication between the tractor and the implement; Figure 5 It is a schematic structural diagram of the agricultural machinery control device provided by the embodiments of the present application; Figure 6 It is a schematic structural diagram of the electronic device provided by the embodiments of the present application. Detailed implementation manners

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Usually, the components of the embodiments of the present application described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, every other embodiment obtained by those skilled in the art without creative efforts belongs to the scope of protection of the present application.

[0018] First, the applicable application scenarios of the present application will be introduced. The present application can be applied to the technical field of agricultural machinery.

[0019] Through research, it is found that there are two core problems in the current collaborative operation between tractors and large square balers: First, the lack of dynamic vehicle speed control. The implement cannot automatically adjust the tractor's vehicle speed or steering according to the real-time sensor status (such as the hay feeding amount), and it relies on manual intervention, resulting in low operation efficiency (easy to occur hay jams), uneven bale shapes, and increased labor intensity. Second, the communication security risk is prominent. The traditional CAN bus protocol lacks a strong authentication mechanism, and the control instructions between the tractor and the implement are easily tampered with or interfered with by illegal devices, seriously threatening operation safety and data integrity.

[0020] Based on this, the embodiment of the present application provides an agricultural machinery control method, control device, electronic device and storage medium. First, the target pressure value is calculated based on the preset target compaction density and forage characteristic parameters, and the pressure balance is maintained by real-time monitoring of the actual pressure and automatic adjustment of the solenoid valve opening; when the pressure reaches the threshold and there is still a deviation, the tractor travel speed is adjusted by reverse output of the vehicle speed control signal to dynamically match the grass feed amount with the baling pressure requirement. This method combines pressure control with vehicle speed regulation, ensures the stability of the grass bale density, improves operating efficiency, solves the problems of uneven density and low efficiency caused by fluctuations in grass feed amount in traditional equipment, and realizes intelligent and precise control of baling quality.

[0021] See also Figure 1 , Figure 1 This is a flow chart of the agricultural machinery control method provided in the embodiment of the present application. Figure 1 As shown in, the agricultural machinery control method provided by the embodiment of the present application includes: S101, receiving a target compaction density of baled grass from a tractor; Here, the tractor acts as a safety control server (server), responsible for executing vehicle control instructions (such as vehicle speed and steering) and ensuring operational safety (such as driver presence verification and fault detection); the tractor includes a multi-way valve control subsystem, a lift control subsystem, a PTO control subsystem (Power Take-Off), a vehicle speed control subsystem, a steering control subsystem, and a human-computer interaction subsystem.

[0022] As a safety control client (client), the large square bale is equipped with sensors and controllers to monitor the operating status (such as bale size, density, and position) in real time, and send control requests to the tractor through the ISOBUS network (ISO 11783 bus network); the large square bale includes a picking control subsystem, a feeding control subsystem, a compacting control subsystem, a knotting control subsystem, and a weighing subsystem.

[0023] In an optional embodiment, the tractor and the large square bale are connected by a hydraulic pipeline for transmitting hydraulic oil to control the action of the hydraulic actuators (such as hydraulic cylinders, hydraulic motors, etc.) of the baler. The hydraulic control valve on the tractor or the solenoid valve on the large square bale is used to adjust the flow and pressure of the hydraulic oil to achieve precise control of the action of the baler.

[0024] The working principle of the large square bale mainly involves the picking, conveying, compressing and baling of hay, as follows: Hay Pickup: A pick-up is usually installed on the front of the large square bale to pick up the hay from the ground. The pick-up consists of a rotating tine or reel that feeds the hay evenly into the baler.

[0025] Forage conveying: The picked-up forage is conveyed to the compression chamber of the baler through a conveying device (such as a chain rake, conveyor belt, etc.). During the conveying process, the forage may undergo preliminary pre-pressing and sorting to facilitate subsequent compression and baling.

[0026] Forage compression: Inside the compression chamber, the forage is gradually compressed into a compact bale under the extrusion of a piston or roller. During the compression process, the hydraulic system provides the necessary pressure to ensure that the bale reaches the required density and shape. Big square bale making usually has an adjustable compaction density function. By adjusting the pressure of the hydraulic system or changing the size of the compression chamber, it can adapt to different forage types and operation requirements.

[0027] Forage baling: When the bale reaches a certain length and density, the baler automatically starts the baling program. The baling program usually includes steps such as winding the rope, tying, and cutting the rope to firmly bind the bale together.

[0028] During the baling process, the electrical system controls the various actions of the baler to ensure the accuracy and reliability of baling. At the same time, the hydraulic system provides the necessary power support to ensure the smooth progress of the baling process.

[0029] Bale discharging: After baling is completed, the bale is discharged outside the baler through a discharging device. The discharging device may include a pusher plate, conveyor belt, etc., which can place the bale smoothly on the ground or convey it to other transportation equipment.

[0030] When the tractor and the implement are started, the driver sets the target compaction density through the human-machine interaction subsystem (the operation display screen of the tractor). This parameter is transmitted to the compaction control subsystem of the big square bale through the ISOBUS bus (the agricultural equipment bus network) and serves as the basis for subsequent calculations and adjustments. Here, when setting the target compaction density, factors such as forage type and operation environment need to be considered to ensure the baling quality.

[0031] S102. Calculate the target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the forage type to be baled; The corresponding compaction control subsystem of the implement combines the target compaction density and the forage characteristics (such as humidity, fiber length) and determines the required target hydraulic pressure value through a preset algorithm.

[0032] For example, the method can be: through experiments or empirical data, establish a comparison table of the target hydraulic pressure values required for different forage types (such as straw, wheat, etc.) under different target compaction densities. The table should include forage type, target compaction density range, and the corresponding target hydraulic pressure value.

[0033] In actual operation, the compaction control subsystem first identifies the type of forage (e.g., through sensor detection or user input). Then, the system looks up the corresponding target hydraulic pressure value in the comparison table based on the target compaction density.

[0034] The compaction control subsystem of the implement calculates the required target hydraulic pressure value by combining the target compaction density and the characteristics of the forage (such as humidity and fiber length). The look-up table method is a simple and practical method for quickly determining the target hydraulic pressure value based on the forage type and the target compaction density. Through this method, it can be ensured that the implement can achieve the required compaction density under different forage types and operating conditions, improving the bale quality and operating efficiency.

[0035] S103. Obtain the actual compaction density of the forage during baling, and determine the actual pressure value according to the actual compaction density; Monitor the actual compaction density through a force sensor and feed the data back to the compaction control subsystem to determine the actual pressure value.

[0036] Here, the force sensor can be installed on the contact surface between the compaction plate and the forage.

[0037] S104. According to the actual pressure value and the target pressure value, adjust the solenoid valve opening to change the actual pressure value applied to the forage during baling; The compaction control subsystem sends a PWM signal (Pulse Width Modulation signal) to the solenoid valve, adjusts the opening to control the hydraulic oil flow rate, and thus changes the actual pressure value.

[0038] Specifically, determine whether the actual pressure value is greater than the target pressure value; If the actual pressure value is greater than the target pressure value, control the solenoid valve opening to increase, so as to control the increase in the hydraulic oil flow rate in the density oil cylinder, push the compaction plate in the piston chamber, and increase the pressure applied to the forage.

[0039] The solenoid valve is connected to the oil inlet and return oil port of the density oil cylinder through an oil pipe to control the inlet and outlet of the hydraulic oil. The piston rod of the density oil cylinder extends into the piston chamber and is connected to the compaction plate to push the compaction plate to move. The forage is placed in the piston chamber, and the compaction plate applies pressure to the forage when moving in the piston chamber; Here, when the implement system determines that the actual pressure value is greater than the target pressure value, it means that the pressure applied to the forage at present is too high and needs to be adjusted. By controlling the solenoid valve opening to increase, the hydraulic oil flow rate in the density oil cylinder increases. The hydraulic oil enters the oil inlet of the density oil cylinder through the oil pipe and pushes the piston rod to extend.

[0040] The piston rod of the density oil cylinder is connected to the compaction plate in the piston chamber. Therefore, the elongation of the piston rod will push the compaction plate to move in the piston chamber, thereby increasing the pressure applied to the forage. In this way, the actual pressure value can be gradually reduced to approach the target pressure value.

[0041] If the actual pressure value is not greater than the target pressure value, the opening of the solenoid valve is controlled to decrease, so as to control the reduction of the hydraulic oil flow in the density oil cylinder, not to push the compaction plate in the piston chamber, and reduce the pressure applied to the forage.

[0042] Here, when the machine system determines that the actual pressure value is not greater than the target pressure value (including the case where the actual pressure value is equal to the target pressure value), it means that the pressure applied to the forage may be appropriate or too small at present, but there is no need to further increase the pressure. In order to prevent excessive pressure or maintain the current appropriate pressure, by controlling the reduction of the opening of the solenoid valve, the hydraulic oil flow in the density oil cylinder is reduced. After the hydraulic oil flow is reduced, the piston rod of the density oil cylinder will no longer elongate or the elongation speed will slow down, so as not to push or slow down the movement of the compaction plate in the piston chamber.

[0043] In this way, the pressure applied to the forage will no longer increase or the increase speed will slow down, which helps to maintain or adjust the actual pressure value near the target pressure value.

[0044] In this step, the solenoid valve is connected to the oil inlet and oil return port of the density oil cylinder through an oil pipe and is responsible for controlling the inflow and outflow of hydraulic oil. This connection method enables the solenoid valve to accurately control the hydraulic oil flow and pressure in the density oil cylinder; the compaction plate is the component that directly applies pressure to the forage. When it moves in the piston chamber, it will compress the forage and make it reach the required compaction density. The entire closed-loop control process realizes the precise control of the forage baling pressure by continuously comparing the actual pressure value with the target pressure value and adjusting the opening of the solenoid valve accordingly.

[0045] S105. When it is detected that the actual pressure value reaches the pressure limit and the opening of the solenoid valve still needs to be adjusted, according to the actual pressure value and the target pressure value, generate and send a vehicle speed control signal to the tractor to control the tractor to adjust the speed and adjust the forage intake.

[0046] When the deviation between the actual pressure value and the target pressure value is too large and the opening of the solenoid valve can no longer meet the adjustment requirements, it is necessary to adjust the vehicle speed of the tractor so that the actual pressure value is as close as possible to the target pressure value.

[0047] Please refer to Figure 2 , Figure 2 which is the flowchart for determining the vehicle speed control signal provided by the embodiment of the present application. As Figure 2 shown in, the flowchart for determining the vehicle speed control signal provided by the embodiment of the present application includes: Here, the vehicle speed control signal includes a first vehicle speed control signal and a second vehicle speed control signal.

[0048] Among them, the vehicle speed control signal is determined by the following method: S201. When it is detected that the actual pressure value reaches the pressure limit value and the solenoid valve opening still needs to be adjusted, determine whether the actual pressure value is greater than the target pressure value; S202. If the actual pressure value is greater than the target pressure value, send the first vehicle speed control signal to the tractor to control the tractor to decelerate and reduce the amount of grass fed into the implement; If the actual pressure value is greater than the target pressure value, it indicates that the amount of grass fed is too much. The system sends the first vehicle speed control signal to the tractor to control the tractor to decelerate to reduce the amount of grass fed.

[0049] S203. If the actual pressure value is less than the target pressure value, send the second vehicle speed control signal to the tractor to control the tractor to accelerate and increase the amount of grass fed into the implement.

[0050] If the actual pressure value is less than the target pressure value, it indicates that the amount of grass fed is insufficient. The system sends the second vehicle speed control signal to the tractor to control acceleration to increase the amount of grass fed.

[0051] The vehicle speed adjustment should be carried out smoothly to avoid causing too much impact on the baling operation. The change amount of the vehicle speed can be dynamically adjusted according to the deviation degree between the actual pressure value and the target pressure value. During the vehicle speed adjustment process, the system should monitor the operating state of the tractor, such as the engine speed, oil temperature, etc., to ensure the safety and reliability of the adjustment process.

[0052] Similarly, the controllable functions of the tractor under other application conditions: Vehicle speed control: It is achieved by adjusting the engine speed or the transmission gear.

[0053] When the tractor receives the first vehicle speed control signal sent by the implement, control the engine speed to decrease by a preset speed or the transmission gear to decrease by one gear. When the tractor receives the second vehicle speed control signal sent by the implement, control the engine speed to increase by a preset speed or the transmission gear to increase by one gear.

[0054] Steering assistance: When the forage is unevenly distributed, generate a fine-tuning steering command (such as turning right when the left feeding amount is large).

[0055] The implement compares whether the pressure values of the density cylinders on the left and right sides are equal. If they are not equal, it indicates that the forage is unevenly distributed. At this time, it is necessary to send a steering control signal to the tractor by adjusting the left and right feeding amounts. If the left feeding amount is large, send a signal for the tractor to turn right. Similarly, if the right feeding amount is large, send a signal for the tractor to turn left.

[0056] Preferably, the tractor speed control and the steering control can be parallel. When allocating functions, the tractor needs to obtain the authorization for controlling the vehicle speed and steering of the implement at the same time.

[0057] Specifically, when the tractor and the implement are started, send the first version information to the tractor, receive the second version information fed back by the tractor, and establish a connection with the tractor according to the version number corresponding to the second version information; Here, when the implement is started, it sends the first version information to the tractor, which includes the list of protocol versions supported by the implement, such as v (Version) 4.1, v5.0, etc.

[0058] Tractor response feedback: After receiving the request, the tractor returns the second version information, which includes the protocol version number supported by the tractor and the priority sorting.

[0059] Version matching rule: Based on the version list, both parties select the highest compatible version (for example, if the implement supports v4.1 / v5.0 and the tractor supports v4.0 / v5.0, then v5.0 is finally selected).

[0060] The implement verifies whether the version number returned by the tractor is within the range supported by itself. If it matches, it sends a ConnectionEstablish message (connection establishment message), otherwise it terminates the communication and reports an error.

[0061] Through the Address Claim mechanism of ISO 11783 (address declaration mechanism), both parties declare unique device addresses in the CAN bus (such as the implement address 0x80 and the tractor address 0x01) to avoid address conflicts.

[0062] After receiving the authorization signal, use digital certificates and encryption mechanisms for two-way authentication of the tractor and the implement to connect the authorized tractor device to the implement.

[0063] Preferably, after the implement and the tractor are connected, send the tractor vehicle speed control function signal to the tractor and receive the feedback signal of the tractor. The tractor vehicle speed control function signal is used to represent that the implement sends a function allocation message to the tractor, requesting to exclusively occupy the tractor speed control function; Here, after the implement and the tractor establish a network connection (such as completing version negotiation and two-way authentication through the ISO 11783 protocol), the implement sends a vehicle speed control function allocation message to the tractor. The message content includes: function identifier, exclusive request flag, unique identifier of the implement (such as device serial number) and timestamp. Through the request function message, obtain the function list supported by the tractor, such as vehicle speed, power take-off shaft PTO (Power Take-Off Shaft), lift, etc.

[0064] After the tractor receives a request, it returns one of the following two types of feedback: Authorization signal: If the vehicle speed control function is not occupied, the tractor allows the implement to have exclusive control and returns an authorization confirmation.

[0065] Rejection signal: If the function is occupied by other devices or there are conflicts, the tractor returns the reason for rejection. At this time, if the function is occupied, the tractor's HMI (Human - Machine Interface, which is the medium for interaction and information exchange between humans and machines) displays a conflict message. The operator can choose whether to release the control right. The function priority can be defined (such as the implement control priority is higher than the HMI), and the tractor automatically rejects requests with a lower priority.

[0066] When it is detected that the feedback signal indicates the authorization signal of the tractor for the implement to exclusively control the tractor's vehicle speed, a speed control signal is sent to the tractor to control the adjustment of the tractor's speed.

[0067] Among them, the implement receives the feedback signal returned by the tractor. The feedback signal can be in two situations: entering the speed control stage and terminating the process and recording the log.

[0068] The implement can dynamically adjust the speed value according to the operation requirements, and the tractor needs to respond in real time and feedback the current speed.

[0069] After the implement completes the operation, it sends a message to release the vehicle speed control function, allowing other devices to re - apply. If the communication between the implement and the tractor is interrupted for more than the set time (such as 10 seconds), the tractor automatically releases the control right and records the event.

[0070] In an optional embodiment, under normal circumstances, the tractor can also receive the speed control signal of the implement, but only after the tractor authorizes the implement to exclusively control the tractor's vehicle speed, will the tractor execute this speed control signal.

[0071] After the implement and the tractor establish a connection, authentication of the tractor and the implement is carried out. If the authentication fails, the communication is terminated to prevent unauthorized devices from intervening.

[0072] Status management: The tractor and the implement synchronize the automation status (such as "ready", "activating") by periodically sending status messages.

[0073] The tractor sends a function request (such as setting a speed value), and the implement responds with the actual status (such as the current speed). Communication anomalies are detected through the heartbeat counter and the request counter. If it times out or there is an error, the safety mechanism is triggered.

[0074] The tractor defines the safety range of the function (such as the maximum speed). When it exceeds the range, it automatically limits the amplitude and notifies the implement. The tractor or the implement gradually releases resources by sending a shutdown heartbeat message to avoid system instability caused by sudden disconnection.

[0075] Please refer to Figure 3 , Figure 3 which is one of the flowcharts for two-way authentication of tractors and implements. As shown in Figure 3 , one of the flowcharts for two-way authentication provided by the embodiments of the present application includes: Specifically, the authentication process between the authentication server (tractor) and the authentication client (implement, exemplified by a large square bale). This process mainly includes the following four stages: Stage 1 (key table check): At the beginning of authentication, the client and the server check their respective lightweight authentication key tables and generate a random challenge code for this authentication session. The random challenge value remains unchanged during an authentication session until authentication succeeds or fails.

[0076] S301. After the implement and the tractor establish a connection, send a status bit to the tractor.

[0077] Before starting the authentication process, the implement checks the lightweight authentication key table inside it to decide whether to perform full authentication (FwA, Full Authentication) or lightweight authentication (LwA, Lightweight Authentication).

[0078] The tractor declares the selected authentication type to the tractor by setting the status bit in the CAN bus message.

[0079] The status bit is used to characterize the first authentication type of the implement; After the implement establishes a network connection (such as when the ISO 11783 protocol is completed), it sets the status bit (e.g., Auth_Type_Bit = 0 indicates LwA, Auth_Type_Bit = 1 indicates FwA) through the CAN bus message to declare the selected authentication type to the tractor.

[0080] Auth_Type_Bit = 0 indicates LwA: When the value of the authentication type status bit (Auth_Type_Bit) is 0, it represents the use of lightweight authentication (Lightweight Authentication) method.

[0081] Auth_Type_Bit = 1 indicates FwA: When the value of the authentication type status bit (Auth_Type_Bit) is 1, it represents the use of full authentication (Full Authentication) method.

[0082] Here, at the initial startup when the device is powered on for the first time or a working unit starts up, full authentication (FwA) is performed by default; if re - authentication is required due to an unexpected shutdown (such as an engine stall), and the previous authentication was successful and the key has not expired, lightweight authentication (LwA) is preferentially attempted.

[0083] Moreover, full authentication (FwA): applicable to the scenarios of first authentication or key expiration, requires a complete exchange of certificates and verification of the signature chain (such as through ECDH key exchange and CA root certificate verification), lightweight authentication (LwA): based on the shared key from the previous successful authentication, only requires a challenge - response protocol to verify key possession, reducing the computational overhead.

[0084] Exemplarily, ECDH key exchange (Elliptic Curve Diffie - Hellman Key Exchange), the elliptic curve Diffie - Hellman key exchange, is a key agreement protocol based on elliptic curve cryptography, used to securely establish a shared key between two communicating parties for subsequent encrypted communication; CA root certificate validation (CA Root Certificate Validation), the process of validating the root certificate of a certificate authority (CA), aims to confirm the legality, validity, and authenticity of the root certificate, thereby ensuring the credibility of other certificates issued based on this root certificate.

[0085] S302. Receive the status information of the tractor and determine the second authentication type of the tractor; After the tractor receives the authentication request from the implement, it performs the following operations according to the Auth_Type field (Authentication Type Field): If it is LwA: Check whether there is a shared key (such as Key_ID = 0x1A2B) in the local LwA key table that matches the implement.

[0086] If it is FwA: Skip the LwA key table check and directly prepare the full authentication process (such as loading the CA root certificate).

[0087] The tractor returns the authentication types and status it supports.

[0088] If the tractor cannot perform authentication currently (such as when dealing with other tasks), set an error code.

[0089] S303. Determine the target authentication type according to the first authentication type and the second authentication type; The tractor performs operations based on the CAN bus message results transmitted by the implement: If the implement selects LwA, the tractor virtual terminal needs to check its own LwA key table; if the implement selects FwA, the tractor can skip the LwA key table check and directly perform full authentication.

[0090] The tractor responds to the implement by returning a CAN bus message. If the tractor cannot perform authentication currently, it needs to set the error code to "participant busy". After the two parties interact through status messages, the authentication type (FwA or LwA) for this time is determined.

[0091] If both the implement and the tractor support lightweight authentication LwA (such as Auth_Type = 0x00 and Server_Auth_Type = 0x00), then LwA is selected.

[0092] Here, if both the implement and the tractor support lightweight authentication (LwA) (for example, the value of the Auth_Type field is 0x00 and the value of the Server_Auth_Type field is 0x00), then lightweight authentication (LwA) is selected.

[0093] If either party only supports full authentication FwA (such as the implement selects LwA but the tractor only supports FwA), then FwA is enforced.

[0094] Here, if either party only supports full authentication (FwA) (for example, the implement selects lightweight authentication (LwA) but the tractor only supports full authentication (FwA)), then full authentication (FwA) is enforced.

[0095] Terminate authentication: If both parties do not support the authentication type selected by the other party (such as the implement selects FwA but the tractor only supports LwA), then terminate the authentication and return an error.

[0096] After the two parties interact through status messages, if it is determined that the target authentication type is LwA, then mark the status as a synchronization point (SYNC, Synchronization Point, which is a specific position or moment set when coordinating between multiple processes, threads, devices, or systems to ensure that they can synchronize operations in a predetermined order or state during execution), indicating that the two parties have reached an agreement on the authentication method.

[0097] S304. When it is detected that the target authentication type represents lightweight authentication, generate a first random challenge code, receive the second random challenge code generated by the tractor, generate a shared key, and calculate the first implement response value based on the second random challenge code and the shared key; When both participating parties have sent CAN bus authentication status messages and the authentication status is set to "Authenticated", their statuses are marked as a synchronization point (SYNC), after which the device and the tractor generate a random challenge code.

[0098] The device generates a 128-bit random challenge code (the first random challenge code R1), which is used as the input for CMAC (Cipher-based Message Authentication Code) calculation.

[0099] The tractor independently generates another 128-bit random challenge code (the second random challenge code R2) and sends it to the device.

[0100] If this is the first authentication (or the key has expired), the two parties exchange public keys and derive a shared key (k) through the ECDH algorithm (Elliptic Curve Diffie-Hellman). For subsequent lightweight authentication, the shared key (k) successfully authenticated last time is reused.

[0101] The device calculates the response value: using the shared key k and the tractor challenge code R2, calculate the first device response value (CMAC_R2 = CMAC(k, R2)).

[0102] Specifically, using the Cipher-based Message Authentication Code (CMAC) algorithm, with the key k and the response value R2 as inputs, the result obtained is CMAC_R2.

[0103] The tractor calculates the response value: using the shared key k and the device challenge code R1, calculate the first tractor response value (CMAC_R1 = CMAC(k, R1)).

[0104] Similarly, using the Cipher-based Message Authentication Code (CMAC) algorithm, with the key k and the response value R1 as inputs, the result obtained is CMAC_R1.

[0105] Phase Four: S305: Send the first device response value to the tractor and receive the first authentication result.

[0106] The first authentication result is determined by the tractor based on the first tractor response value and the first device response value. The first tractor response value is generated based on the shared key and the first random challenge code.

[0107] The device sends the second tractor response value CMAC_R2 to the tractor, and the tractor sends the first tractor response value CMAC_R1 to the device.

[0108] After the implement receives the first tractor response value CMAC_R1, it compares it with the locally calculated CMAC(k, R1). If they are the same, the authentication is successful.

[0109] After the tractor receives CMAC_R2, it compares it with the locally calculated CMAC(k, R2). If they are the same, the authentication is successful.

[0110] Success: Both parties send an authentication success message, including an authentication success flag (e.g., Success = 0x01).

[0111] Failure: Send an authentication failure message, including an error code.

[0112] The authentication type negotiation passes the status bit and key table check, realizes the dynamic selection of full authentication and lightweight authentication, balances security and efficiency, verifies the possession of the private key by both parties based on the CMAC algorithm and the shared key, ensures the authenticity of the identity. The lightweight authentication optimization shortens the authentication time from 60 seconds of full authentication to the millisecond level through key reuse and parallel computing, meeting the real-time requirements of field operations. This solution meets the distributed security requirements of the ISO 11783 protocol and provides an efficient and reliable mutual authentication mechanism for scenarios such as intelligent agricultural machinery and driverless.

[0113] Please refer to Figure 4 , Figure 4 Figure 2 of the flowchart for mutual authentication between the tractor and the implement, as Figure 4 shown in, the second flowchart of the mutual authentication provided by the embodiments of the present application includes: Phase 1: Both the tractor and the implement generate challenge codes; Phase 2: Only applicable to full authentication, perform mutual certificate exchange and certificate verification between the tractor and the implement. Successfully completing Phase 2 can prove that the tractor and the implement respectively hold valid and authentic server certificates and client certificates.

[0114] Phase 2 is only executed when the tractor and the implement perform full authentication FwA. During the lightweight authentication LwA process, this phase is completely skipped.

[0115] S401. When detecting that the target authentication type indicates full authentication, send a certificate request to the tractor and obtain the digital certificate of the tractor; The tractor and the implement independently send certificate requests to each other and respond to the certificates: The tractor and the implement independently respond to the certificate requests of each other.

[0116] If the target authentication type is full authentication (FwA), for example, the device sends a certificate request to the server (such as the tractor virtual terminal) via the CAN bus, and the tractor returns its digital certificate, which includes the public key, validity period, issuer information, and the Certificate Category Identifier (CCID) used to distinguish and identify different types of digital certificates.

[0117] CAN bus message: Use PGN 65281 (Certificate Request) and PGN 65283 (Certificate Response) to exchange certificates, and the message format shall comply with the ISO 11783-5 standard.

[0118] Here, PGN 65281 (Certificate Request): Parameter Group Number 65281 (Certificate Request), which is used to initiate a certificate acquisition request message from one device to another in a communication system that complies with the ISO 11783-5 standard.

[0119] PGN 65283 (Certificate Response): Parameter Group Number 65283 (Certificate Response), which is used to respond to the received certificate request message and provide the corresponding certificate information in a communication system that complies with the ISO 11783-5 standard.

[0120] ISO 11783-5: International Organization for Standardization Standard 11783-5, which is part of the Tractors and Machinery for Agriculture and Forestry - Serial Control and Communication Data Network (ISOBUS), and stipulates the protocols, message formats, etc. of data communication to ensure interoperability between different devices.

[0121] S402. Determine whether the tractor meets the certificate authentication conditions.

[0122] The authentication conditions are used to represent that the received digital certificate does not exist in the local Certificate Revocation List, the certificate chain is valid, the Certificate Category Identifier in the digital certificate is consistent with the preset certificate category identifier, and the fields of the transmitted information are consistent with the corresponding fields in the tractor production certificate. CRL check: Both parties check whether the received certificate exists in the local Certificate Revocation List (CRL, which is a list containing digital certificates that have been revoked but have not yet expired), and the CRL itself must have been verified for validity. Certificate chain verification: If none of the received certificates have been revoked, both parties verify the validity of the certificate chain (such as the signature chain, validity period, etc.). Manufacturer series certificate comparison: 1) Compare the CCID (Certificate Category Identifier) in the certificate; 2) Check whether the supported functions in the CAN bus message match the entries in the manufacturer series certificate.

[0123] ISOBUS information consistency check: Verify whether the information passed by the other party through ISOBUS (such as the ISOBUS name, excluding the identity number) is consistent with the fields in the other party's production certificate.

[0124] Here, after the implement parses the tractor certificate, it checks whether it exists in the local CRL (such as obtaining the CRL through the CRL_URI field and verifying its validity); verifies the signature validity of the certificate chain (such as whether the root certificate is trusted) and the validity period (such as the Not Before and Not After fields); compares the CCID in the certificate with the preset value (such as CCID = 0x01 indicates an agricultural equipment certificate); checks whether the supported functions (such as the Supported_Functions field) in the CAN bus message match the certificate entries and verifies whether the name passed by the tractor through ISOBUS (such as the Device_Name) is consistent with the SubjectAlternative Name field in the certificate.

[0125] Among them, CRL_URI (Certificate Revocation List Uniform Resource Identifier) is used to uniquely identify and locate the address of the certificate revocation list (CRL). The implement obtains the CRL file through this field to check whether the tractor certificate has been revoked subsequently.

[0126] CRL (Certificate Revocation List) contains a list of digital certificates that have been revoked but have not yet expired. After the implement obtains the CRL, it checks whether the serial number of the tractor certificate exists in this list. If it exists, it indicates that the certificate has been revoked and is not trustworthy.

[0127] Validation of Certificate Chain Signature Validity: The certificate chain is a chain structure composed of multiple certificates, from the end-entity certificate (such as the tractor certificate) to the root certificate. Verifying the signature validity means checking whether the signature of each certificate is correctly generated by the private key of its superior certificate. For example, verifying whether the signature of the tractor certificate is generated by the private key of the intermediate certificate, and whether the signature of the intermediate certificate is generated by the private key of the root certificate.

[0128] Root Certificate, the top-level certificate in the certificate chain, is usually issued by a trusted Certificate Authority (CA). The device needs to pre-store the trusted root certificate locally for verifying the signature of the certificate chain. If the root certificate is not trusted, then the entire certificate chain will be regarded as untrusted.

[0129] Not Before (Not Before Date, effective date), the date and time specified in the certificate when this certificate starts to take effect. The device will check whether the current date and time are after the time specified in this field. If not, the certificate has not taken effect and cannot be used. For example, if the Not Before field of the certificate is 2024-01-01 00:00:00 and the current date is December 31, 2023, then the certificate has not taken effect.

[0130] Not After (Not After Date, expiration date), the date and time specified in the certificate when this certificate expires. The device will check whether the current date and time are before the time specified in this field. If not, the certificate has expired and cannot be used. For example, if the Not After field of the certificate is 2025-12-31 23:59:59 and the current date is January 1, 2026, then the certificate has expired.

[0131] CCID (Certificate Category Identifier), used to identify the category of the certificate. The device will compare the CCID in the certificate with the preset value to determine whether the type of the certificate meets the requirements. For example, preset CCID = 0x01 indicates an agricultural equipment certificate. If the CCID in the tractor certificate is 0x01, it means that this certificate is an agricultural equipment certificate.

[0132] Supported_Functions (Supported Functions Field), a field included in the CAN bus message, used to indicate the functions supported by the tractor. The device will check whether the content of this field matches the functions allowed in the certificate entry to ensure that the tractor has the permission to perform specific operations. For example, if the certificate entry stipulates that the tractor supports tillage and seeding functions, but the Supported_Functions field only includes the harvesting function, then they do not match.

[0133] ISOBUS (International Organization for Standardization 11783), is a serial control and communication data network standard for agricultural and forestry machinery. The tractor transmits information such as the device name through ISOBUS, and the implement needs to verify whether this information is consistent with the relevant fields in the certificate.

[0134] Device_Name (device name), the name transmitted by the tractor through ISOBUS. The implement will check whether this name is consistent with the Subject Alternative Name field in the certificate to ensure the authenticity and legality of the device identity. For example, if the Subject Alternative Name field in the certificate is Tractor-123, and the Device_Name transmitted by the tractor is Tractor-456, then they are inconsistent.

[0135] S403: If the tractor does not meet the certificate authentication conditions, send an authentication failure signal to the tractor; If any of the above is inconsistent, terminate the authentication process.

[0136] If the tractor certificate does not meet any of the authentication conditions (such as being revoked, the chain is invalid, CCID does not match), the client sends an authentication failure signal (PGN 65292, Error_Code = 0x04).

[0137] Here, PGN 65292 (Parameter Group Number 65292), in the ISOBUS (International Organization for Standardization 11783, Tractors and machinery for agriculture and forestry - Serial control and communication data network) communication protocol, PGN is used to identify specific types of data messages. PGN 65292 is a predefined parameter group number. The client uses the message with this number to send an authentication failure signal so that the receiving party can accurately identify the type and purpose of the message. For example, in the communication network of agricultural machinery, different PGNs correspond to different functional messages, such as sensor data transmission, control instructions, etc. PGN 65292 is specifically used for authentication-related failure notifications.

[0138] Error_Code = 0x04 (Error Code with Hexadecimal Value 0x04, the error code with a hexadecimal value of 0x04), the error code is used to indicate the specific error type. During the authentication process, when the tractor certificate does not meet any of the authentication conditions, the client will set Error_Code = 0x04 to indicate authentication failure. Different error codes correspond to different error scenarios. For example, 0x01 may indicate an incorrect certificate format, and 0x02 may indicate an expired certificate, etc. 0x04 is a specific identifier, and the recipient can quickly locate the problem of certificate authentication failure based on this code.

[0139] For example, the error codes can be defined as: ERR_CERT_REVOKED (certificate revoked), ERR_CHAIN_INVALID (invalid certificate chain), ERR_CCID_MISMATCH (CCID mismatch), ERR_ISOBUS_MISMATCH (inconsistent ISOBUS information).

[0140] S404. If the tractor meets the certificate authentication conditions, send a certificate authentication success signal to the tractor, generate the first random challenge code, and receive the second random challenge code generated by the tractor; After successful verification, the tractor and the implement send notifications to each other to confirm the completion of the certificate chain check.

[0141] If the tractor certificate passes all checks, the implement sends a certificate authentication success signal, the implement generates a 256-bit random challenge code (R1), and sends it to the tractor.

[0142] The tractor independently generates another 256-bit random challenge code (R2) and returns it to the implement.

[0143] Phase 3 (Key Exchange): The server and the client perform Elliptic Curve Diffie-Hellman (ECDH) key exchange to exchange the shared encryption key.

[0144] S405. Generate the shared key based on the first random challenge code and the second random challenge code; Both parties independently calculate the shared key (k), and use the key derivation function (KDF, Key Derivation Function) to generate the session key based on the shared key and the challenge code.

[0145] S406. Split the shared key into the first independent key and the second independent key, send the first independent key to the tractor, and receive the second independent key sent by the tractor; Based on the shared key and the challenge values of both parties, independently generate a copy of the LwA key, and split the LwA key into two independent keys.

[0146] Here, the client splits the shared key into Key_A and Key_B (e.g., the first 128 bits and the last 128 bits of the SHA-256 hash).

[0147] The client sends Key_A to the tractor, and the tractor sends Key_B to the client.

[0148] Key_A (No standard full - form in this context, can be considered as apart of the derived key labeled as Key_A, the key A), after the client performs a SHA-256 hash operation on the shared key, takes the first 128 bits of the hash result as Key_A. It is a part derived from the shared key and will be used later to ensure the security of communication between the client and the tractor, such as encrypting some communication data or performing message authentication, etc.

[0149] Key_B (No standard full - form in this context, can be considered as apart of the derived key labeled as Key_B, the key B), after the client performs a SHA-256 hash operation on the shared key, takes the last 128 bits of the hash result as Key_B. Similar to Key_A, Key_B is also a part derived from the shared key and is used in the security mechanism during the communication process, such as possibly encrypting another part of the communication data or performing different message authentication operations.

[0150] Compared with traditional key exchange algorithms (such as RSA or the classical Diffie - Hellman), ECDH can achieve higher real - time performance under the limited resources of embedded devices (CPU, memory, power consumption) with shorter keys, lower computational load and memory occupancy, and in the case of the low - bandwidth CAN bus.

[0151] For example, RSA (Rivest - Shamir – Adleman, named after the surnames of the three inventors), RSA is an asymmetric encryption algorithm and can also be used for key exchange. Its basic principle is based on the mathematical problem of large number factorization. During the key exchange process, one party (such as Alice) generates a pair of keys: a public key and a private key. The public key can be made public, while the private key must be kept secret.

[0152] For example, when A wants to exchange keys with B, A sends its public key to B. B uses A's public key to encrypt a randomly generated symmetric key (used for subsequent encrypted communication data), and then sends the encrypted result to A. After receiving it, A uses its private key to decrypt the encrypted content to obtain the symmetric key shared with B.

[0153] Phase Four: (Challenge - Response) A two - way challenge - response protocol between the server and the client. After successfully exchanging the shared key, both parties execute the challenge - response protocol based on the CMAC (Cipher - based Message Authentication Code) algorithm of symmetric encryption. The purpose of this phase is to verify that the server and the client respectively possess the private keys corresponding to the public keys in the certificates exchanged and authenticated with each other. The possession of the private key proves the authenticity of the peer's identity.

[0154] S407. Calculate the second terminal response value according to the second random challenge code and the second independent key; In this step, the client uses Key_B and R2 to calculate the CMAC response value (CMAC_R2 = CMAC(Key_B, R2)).

[0155] In this expression, Key_B is the key used to calculate CMAC, and R2 is the message or data to be authenticated. The client uses Key_B as the key to perform CMAC calculation on R2 to obtain the CMAC_R2 value. This value can be used for subsequent identity authentication or message integrity verification.

[0156] CMAC_R2 is the result obtained by the client performing CMAC calculation on R2 using Key_B. It is a binary value of a fixed length and is used to verify the integrity and authenticity of R2. During subsequent communication, the receiving party can recalculate CMAC_R2 and compare it with the received value to determine whether R2 has been tampered with and whether the sender possesses the correct Key_B.

[0157] The tractor uses Key_A and R1 to calculate the CMAC response value (CMAC_R1 = MAC(Key_A, R1)).

[0158] Here, Key_A is the key element used to calculate CMAC. It is usually determined and shared between the client and the tractor through a specific key exchange protocol or negotiation mechanism. The security of Key_A is crucial. Only the party with the correct Key_A can correctly calculate and verify the CMAC value, thus ensuring the security and reliability of the communication.

[0159] R1 is the message or data that needs to be authenticated. In a communication scenario, R1 can be a random number generated by the tractor, specific instruction information, status data, etc. R1 carries the key information that the tractor wants to convey to the client, and the CMAC calculation is to ensure that this information is not tampered with during transmission.

[0160] The tractor uses Key_A as the key, takes R1 as the input message, and calculates using the CMAC algorithm to finally obtain the CMAC_R1 value. The CMAC algorithm performs a series of complex encryption and operation operations on the input message and the key based on a block cipher (such as AES) to generate a fixed-length binary value as the authentication code.

[0161] The client sends CMAC_R2 to the tractor, and the tractor sends CMAC_R1 to the client.

[0162] S408: Send the second implement response value to the tractor and receive the second authentication result.

[0163] The second authentication result is determined by the tractor based on the second tractor response value and the second implement response value. The second tractor response value is generated according to the first independent key and the first random challenge code.

[0164] Here, the client verifies whether CMAC_R1 is consistent with the locally calculated CMAC(Key_A, R1), and the tractor verifies whether CMAC_R2 is consistent with the locally calculated CMAC(Key_B, R2).

[0165] If the verification is successful, both parties send PGN 65290 (Success = 0x01). If the verification fails, send PGN 65292 (Error_Code = 0x10, indicating CMAC mismatch).

[0166] In this step, if the CMAC verification between the client and the tractor is successful, both parties will send a PGN 65290 message, in which the carried identifier is Success = 0x01. Here, Success is an identifier field used to indicate the verification result, and 0x01 is its specific hexadecimal value, representing the state of successful verification. When both parties receive the PGN 65290 sent by the other party and the Success identifier in it is 0x01, it can be confirmed that the current CMAC verification has passed smoothly, and the two parties can continue to carry out normal communication interactions, such as data transmission, instruction issuance and execution, etc.

[0167] If the CMAC verification between the client and the tractor fails, both parties will send a PGN 65292 message, in which the carried error code is Error_Code = 0x10. Error_Code is a field used to identify the specific reason for the verification failure, and 0x10 is its specific hexadecimal value. In this scenario, this value clearly indicates that the reason for the verification failure is CMAC mismatch. When one party receives the PGN 65292 sent by the other party and the Error_Code in it is 0x10, it can be clearly known that the current CMAC verification fails due to CMAC value mismatch. At this time, both parties should suspend the current communication process and take corresponding measures to troubleshoot the problem, such as checking whether the key is correct, checking whether there is interference or error in the communication process, etc. After the problem is solved, the verification process is restarted.

[0168] When the ECDH-based key exchange and CMAC-based challenge-response are successfully completed for the first time, during subsequent startups, only lightweight LwA is performed between the server and the client. The full authentication process may take 60 seconds or longer (varying depending on the manufacturer and the performance of the connected devices). During the initial startup of the work unit (such as when the user starts the device), a longer authentication time is acceptable, but during field operations, if re-authentication is required due to an unexpected shutdown (such as restarting after the engine accidentally stalls), an overly long authentication time will not be acceptable. Therefore, a faster lightweight authentication LwA is introduced.

[0169] The full authentication executes in phases one, two, three, and four, while the lightweight authentication only needs to execute phases one and four.

[0170] The agricultural machinery control method, control device, electronic device, and storage medium provided by the embodiments of this application receive the target compaction density of the forage during baling from a tractor; calculate the target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; obtain the actual compaction density of the forage during baling, and determine the actual pressure value according to the actual compaction density; adjust the solenoid valve opening degree according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling; when it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening degree still needs to be adjusted, generate and send a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value to control the tractor to adjust its speed and adjust the forage feeding amount. Through this application, the implement can control the tractor speed in reverse, adjust the forage feeding amount, and improve the forage baling efficiency.

[0171] The agricultural machinery control method, control device, electronic device, and storage medium of this application are applied to large square bales, but are also applicable to the safety control of other implements for tractors, such as the control of tractor speed and PTO when a round baler discharges bales.

[0172] Different from the traditional vehicle speed adjustment that relies on manual intervention, this application realizes the dynamic vehicle speed control of the implement for the tractor, thereby improving the operation efficiency, reducing the risk of forage jamming, and optimizing the operation quality.

[0173] This application ensures a high level of security in the communication and control process between the tractor and the implement by introducing an authentication mechanism (phase one, phase two, phase three, and phase four) and a safety control method. Only authenticated devices can participate in the control, avoiding the access of unauthorized devices, thereby preventing potential safety hazards in the communication and control process.

[0174] This application uses the ISOBUS communication protocol as the main data transmission method between the tractor and the implement. ISOBUS ensures the effective interconnection and interoperability between the tractor and the implement through standardized interfaces and data formats.

[0175] This application ensures the communication security between the tractor and the implement through mutual authentication and the Elliptic Curve Diffie-Hellman (ECDH) key exchange process. By using ECDH (phase three) and the Key Derivation Function (KDF) (phase three), a shared encryption key can be generated, and the authenticity of both parties' identities can be verified through symmetric encryption.

[0176] This application introduces a function allocation mechanism in the communication process, enabling the implement to request the control of specific functions of the tractor (such as vehicle speed), and the corresponding allocation and management are carried out through the server. Only under legal function allocation circumstances can the implement control specific operations of the tractor.

[0177] Through multi-level security measures including key exchange (Phase Three), challenge-response mechanism (Phase Four), and authentication process, this application clearly ensures the security and efficiency of communication. Especially in the environment where embedded devices have limited resources and low bandwidth, the ECDH key exchange algorithm has higher real-time performance compared to traditional algorithms.

[0178] The dynamic vehicle speed control method in this application includes a technical method where the implement adjusts the tractor speed in real time according to sensors. The safety control mechanism includes ensuring secure control and communication between the tractor and the implement through an authentication mechanism and a key exchange protocol.

[0179] The mutual authentication and ECDH key exchange in this application provide for ensuring the legality and credibility of both devices through mutual authentication and ECDH key exchange.

[0180] The dynamic vehicle speed adjustment in this application reduces the no-load and grass jamming time, and the operation efficiency is increased by 15% - 20%. The mutual authentication mechanism in this application eliminates illegal control instructions and improves the safety of agricultural operations.

[0181] The implement in this application controls the functions of the tractor according to the authorization request. This application is applicable to safety control schemes for various implements, not only for large square balers, but also for other types of implements with tractor control requirements, such as round balers and fertilizer spreaders.

[0182] Based on the same inventive concept, an agricultural machinery control device corresponding to the agricultural machinery control method is also provided in the embodiments of this application. Since the principle of solving problems by the device in the embodiments of this application is similar to the above-mentioned agricultural machinery control method in the embodiments of this application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be elaborated.

[0183] Please refer to Figure 5 , Figure 5 which is the structural schematic diagram of the agricultural machinery control device provided by the embodiments of this application. As Figure 5 shown in the target compaction density receiving module 501 is used to receive the target compaction density corresponding to the forage during baling from the tractor; the target pressure value calculating module 502 is used to calculate the target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; the actual pressure value determining module 503 is used to obtain the actual compaction density of the forage during baling and determine the actual pressure value according to the actual compaction density; the adjustment module 504 is used to adjust the solenoid valve opening according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling; The vehicle speed control signal sending module 505 is configured to generate and send a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value when it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening still needs to be adjusted, so as to control the tractor to adjust its speed and the grass feeding amount.

[0184] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of the electronic device provided by the embodiment of the present application. As Figure 6 shown in, the electronic device 300 includes a processor 310, a memory 320, and a bus 330.

[0185] The memory 320 stores machine-readable instructions executable by the processor 310. When the electronic device 300 runs, the processor 310 communicates with the memory 320 through the bus 330. When the machine-readable instructions are executed by the processor 310, the steps of the agricultural machinery control method in the method embodiment as described above can be executed. The specific implementation manner can refer to the method embodiment and will not be elaborated here. Figure 1 shown, and the steps of the agricultural machinery control method in the method embodiment as described above can be executed. The specific implementation manner can refer to the method embodiment and will not be elaborated here.

[0186] The embodiment of the present application further provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is run by a processor, the steps of the agricultural machinery control method in the method embodiment as described above can be executed. The specific implementation manner can refer to the method embodiment and will not be elaborated here. Figure 1 shown, and the steps of the agricultural machinery control method in the method embodiment as described above can be executed. The specific implementation manner can refer to the method embodiment and will not be elaborated here.

[0187] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0188] In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings, direct couplings, or communication connections shown or discussed with each other can be through some communication interfaces. The indirect couplings or communication connections between devices or units can be in electrical, mechanical, or other forms.

[0189] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or may be distributed over multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0190] In addition, each functional unit in various embodiments of the present application may be integrated into one processing unit, may exist separately as individual physical units, or two or more units may be integrated into one unit.

[0191] If the described function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0192] Finally, it should be noted that: the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, and are not intended to limit it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An agricultural machinery control method, characterized in that, Applied to a machine, including: Receiving the target compaction density of the forage corresponding to the bailing operation from a tractor; Calculating the target pressure value of the forage during bailing according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; Obtaining the actual compaction density of the forage during bailing and determining the actual pressure value according to the actual compaction density; Adjusting the solenoid valve opening according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during bailing; When it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening still needs to be adjusted, generating and sending a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value to control the tractor to adjust its speed and adjust the forage intake; 2. The method according to claim 1, wherein The vehicle speed control signal includes a first vehicle speed control signal and a second vehicle speed control signal, wherein the vehicle speed control signal is determined by the following method: When it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening still needs to be adjusted, determining whether the actual pressure value is greater than the target pressure value; If the actual pressure value is greater than the target pressure value, sending a first vehicle speed control signal to the tractor to control the tractor to decelerate and reduce the forage intake of the machine; If the actual pressure value is less than the target pressure value, sending a second vehicle speed control signal to the tractor to control the tractor to accelerate and increase the forage intake of the machine.

3. The method according to claim 1, wherein The adjusting the solenoid valve opening according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during bailing includes: Determining whether the actual pressure value is greater than the target pressure value; If the actual pressure value is greater than the target pressure value, controlling the solenoid valve opening to increase to control the increase in the hydraulic oil flow in the density oil cylinder, pushing the compaction plate in the piston chamber, increasing the pressure applied to the forage. The solenoid valve is connected to the oil inlet and oil return port of the density oil cylinder through a pipeline to control the inflow and outflow of hydraulic oil. The piston rod of the density oil cylinder extends into the piston chamber and is connected to the compaction plate to push the compaction plate to move. The forage is placed in the piston chamber, and the compaction plate applies pressure to the forage when moving in the piston chamber; If the actual pressure value is not greater than the target pressure value, controlling the solenoid valve opening to decrease to control the decrease in the hydraulic oil flow in the density oil cylinder, not pushing the compaction plate in the piston chamber, and reducing the pressure applied to the forage.

4. The method according to claim 1, wherein The method further includes: When the tractor and the machine are started, sending the first version information to the tractor, receiving the second version information fed back by the tractor, and establishing a connection with the tractor according to the version number corresponding to the second version information; After receiving the authorization signal, using digital certificates and encryption mechanisms for two-way authentication of the tractor and the machine to connect the authorized tractor device to the machine.

5. The method according to claim 4, wherein The method further includes: After the machine is connected to the tractor, sending a tractor vehicle speed control function signal to the tractor and receiving the feedback signal of the tractor. The tractor vehicle speed control function signal is used to represent that the machine sends a function allocation message to the tractor, requesting to exclusively occupy the tractor speed control function. When it is detected that the feedback signal represents an authorization signal for the implement to exclusively occupy the tractor speed, a speed control signal is sent to the tractor to control the adjustment of the tractor speed.

6. The method according to claim 5, wherein Two-way authentication is performed in the following manner: After the implement establishes a connection with the tractor, a status bit is sent to the tractor, and the status bit is used to represent the first authentication type of the implement; Receive the status information of the tractor and determine the second authentication type of the tractor; According to the first authentication type and the second authentication type, determine the target authentication type; When it is detected that the target authentication type represents lightweight authentication, generate a first random challenge code, receive the second random challenge code generated by the tractor, generate a shared key, and calculate a first implement response value according to the second random challenge code and the shared key; Send the first implement response value to the tractor and receive a first authentication result, where the first authentication result is determined by the tractor according to a first tractor response value and the first implement response value, and the first tractor response value is generated according to the shared key and the first random challenge code.

7. The method according to claim 6, wherein The method further includes: When it is detected that the target authentication type represents full authentication, send a certificate request to the tractor and obtain the digital certificate of the tractor; Determine whether the tractor meets the certificate authentication conditions, where the authentication conditions are used to represent that the received digital certificate does not exist in the local certificate revocation list, the certificate chain is valid, the certificate classification identifier in the digital certificate is consistent with the preset certificate classification identifier, and the fields of the transmitted information are consistent with the corresponding fields in the tractor production certificate; If the tractor does not meet the certificate authentication conditions, send an authentication failure signal to the tractor; If the tractor meets the certificate authentication conditions, send a certificate authentication success signal to the tractor, generate a first random challenge code, and receive the second random challenge code generated by the tractor; Generate a shared key according to the first random challenge code and the second random challenge code; Split the shared key into a first independent key and a second independent key, and send the first independent key to the tractor and receive the second independent key sent by the tractor; Calculate a second implement response value according to the second random challenge code and the second independent key; Send the second implement response value to the tractor and receive a second authentication result, where the second authentication result is determined by the tractor according to a second tractor response value and the second implement response value, and the second tractor response value is generated according to the first independent key and the first random challenge code.

8. An agricultural machinery control device, characterized in that, It includes: A target compaction density receiving module, which is used to receive the target compaction density corresponding to the forage during baling from the tractor; A target pressure value calculation module, which is used to calculate the target pressure value of the forage during baling according to the target compaction density and the forage parameters corresponding to the type of forage to be baled; An actual pressure value determination module, which is used to obtain the actual compaction density of the forage during baling and determine the actual pressure value according to the actual compaction density; An adjustment module, which is used to adjust the solenoid valve opening according to the actual pressure value and the target pressure value to change the actual pressure value applied to the forage during baling; A vehicle speed control signal sending module, configured to generate and send a vehicle speed control signal to the tractor according to the actual pressure value and the target pressure value when it is detected that the actual pressure value reaches the pressure limit and the solenoid valve opening still needs to be adjusted, so as to control the tractor to adjust its speed and the grass feeding amount.

9. An electronic device, characterized in that, It includes: A processor, a memory and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus. The processor executes the machine-readable instructions to perform the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium. When the computer program is run by the processor, it performs the steps of the method according to any one of claims 1 to 7.

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