Tractor power reversing control method, controller, system, and medium

Abstract

The present application relates to the field of agricultural machinery control technology, and discloses a tractor power reversing control method, controller, system and medium. The method comprises the following steps: when the gear change information of the tractor shows that the driver intends to control the tractor to enter the forward gear or the reverse gear, the neutral switch valve is controlled to be closed so that the clutch assembly oil circuit is correspondingly turned on, and a pressure control strategy based on twice pressure pre-charging and time-sharing pressure boosting is correspondingly executed for the forward proportional valve or the reverse proportional valve until a preset maximum pressure ensuring no-slip engagement of the corresponding clutch is reached, so that the corresponding proportional valve is opened and the pressure drives the corresponding clutch to engage, thereby driving the gearbox to switch gears. The present application controls the corresponding proportional valve based on the pressure control strategy of twice pre-charging and time-sharing pressure boosting to drive the clutch to engage quickly, and at the same time avoids that the impact of clutch engagement is too large.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery control technology, specifically to a tractor power reversal control method, controller, system, and medium. Background Technology

[0002] The modernization of agricultural machinery is a prerequisite for the modernization of agriculture, and tractors are the most important part of this development. Among them, tractors with power-reversing capabilities have significant advantages, mainly reflected in the following aspects:

[0003] 1) Compared with the previous mechanical shifting structure, the electro-hydraulic control has a small operating torque and is easy to use;

[0004] 2) It shortens the tractor's turning time, saving 25-35 seconds per turn, thus improving work efficiency;

[0005] 3) It lays the technological foundation for autonomous driving, and the commutation process is electrified, enabling automatic commutation by receiving signals from the vehicle controller.

[0006] However, existing control schemes for power reversal in tractors are prone to vibration, impact, or excessive load on the transmission system when the clutch engages quickly, affecting the user experience. Summary of the Invention

[0007] The purpose of this invention is to provide a tractor power reversing control method, controller, system, and medium to at least partially solve the above-mentioned technical problems.

[0008] To achieve the above objectives, the present invention provides a tractor power reversing control method. The tractor is equipped with a forward proportional valve for controlling the engagement and disengagement of the forward clutch, a reverse proportional valve for controlling the engagement and disengagement of the reverse clutch, and a neutral switch valve for controlling the supply and disconnection of the clutch assembly oil circuit. The tractor power reversing control method includes: acquiring gear change information of the tractor; and when the gear change information indicates that the driver intends to control the tractor to enter a forward or reverse gear, controlling the neutral switch valve to close so that the clutch assembly oil circuit is opened accordingly; and correspondingly executing a pressure control strategy for the forward proportional valve or the reverse proportional valve so that the forward proportional valve or the reverse proportional valve is opened and the corresponding clutch is engaged by pressure, thereby driving the tractor's gearbox to perform gear shifting. The pressure control strategy includes: performing a first pressure pre-charge on the forward proportional valve or the reverse proportional valve; after performing the first pressure pre-charge to a first preset time, performing a second pressure pre-charge on the forward proportional valve or the reverse proportional valve, wherein the pressure corresponding to the second pressure pre-charge is less than the pressure pre-charge of the first pressure; and after performing the second pressure pre-charge to a second preset time, performing a time-sharing pressure increase control strategy on the forward proportional valve or the reverse proportional valve until a preset maximum pressure is reached to ensure that the corresponding clutches are engaged without slippage.

[0009] Preferably, obtaining the gear change information of the tractor includes: obtaining the execution action status information of the gear control mechanism of the tractor, wherein the gear control mechanism includes a shift lever and an electronic clutch pedal; obtaining the current gear status information of the transmission; and combining the execution action status information of the gear control mechanism and the current gear status information of the transmission to determine the gear change information reflecting the driver's intention.

[0010] Preferably, the tractor power reversing control method further includes: when the gear change information indicates that the driver intends to control the tractor to disengage from forward or reverse gear, controlling the pressure applied to the forward proportional valve or the reverse proportional valve to be zero, so that the forward proportional valve or the reverse proportional valve is closed and the corresponding clutch is disengaged; or when the gear change information indicates that the driver intends to perform emergency braking, controlling the neutral switch valve to open, so that the clutch assembly oil circuit is cut off accordingly.

[0011] Preferably, the tractor power reversing control method further includes: controlling the engine speed to be less than or equal to a preset speed when the corresponding clutch is pressure-driven to perform an engagement action; and controlling the engine speed in response to the driver's throttle operation after the corresponding clutch is fully engaged.

[0012] Preferably, the time-segmented pressure boosting control strategy includes: in a first time segment, applying a first pressure to the forward proportional valve or the reverse proportional valve until the corresponding clutch chamber completes oil filling and pressure boosting and is ready to enter the clutch friction plate free travel control stage; in a second time segment, controlling the pressure applied to the forward proportional valve or the reverse proportional valve to rise from the first pressure to a second pressure in a ramp manner, the second pressure causing the corresponding clutch to reach the critical point for performing engagement action; and in a third time segment, controlling the pressure applied to the forward proportional valve or the reverse proportional valve to continue rising from the second pressure to the preset maximum pressure in a ramp manner.

[0013] The present invention also provides a power swerving controller for a tractor, comprising: a memory storing a program capable of running on a processor; and the processor configured to implement any of the aforementioned power swerving control methods when executing the program.

[0014] Preferably, the power reversing controller is the tractor's transmission control unit (TCU), and the TCU is configured to run on the Codesys platform.

[0015] The present invention also provides a tractor power reversing control system, comprising: a gear shifting mechanism including a gear shift lever and an electronic clutch pedal, wherein the gear shifting mechanism is configured to generate corresponding execution action state information based on the driver's operation of the gear shift lever and the electronic clutch pedal; a power reversing valve assembly including a forward proportional valve for controlling the engagement and disengagement of the tractor's forward clutch, a reverse proportional valve for controlling the engagement and disengagement of the tractor's reverse clutch, and a neutral switch valve for controlling the supply and disconnection of the clutch assembly oil circuit of the tractor; and any of the above-mentioned power reversing controllers being configured to combine the execution action state information obtained from the gear shifting mechanism and the tractor's current gear state information to generate gear change information reflecting the driver's intention, and to control the operation of the power reversing valve assembly based on the gear change information to control the engagement, disengagement, or oil circuit opening and closing of the corresponding clutch, thereby driving the tractor's gearbox to perform gear shifting.

[0016] Preferably, the tractor power swerving control system further includes an interactive device that communicates with the power swerving controller and interacts with the power swerving controller in response to user operations.

[0017] Preferably, the tractor power reversing control system further includes an engine control unit (ECU), which communicates with the power reversing controller to provide the current engine speed to the power reversing controller; and the power reversing controller is further configured to send a speed limiting command to the ECU based on the engagement, disengagement or oil circuit status of the corresponding clutch and the current engine speed.

[0018] The present invention also provides a machine-readable storage medium storing instructions for causing a machine to perform any of the above-described tractor power reversing control methods.

[0019] Through the above technical solution, the present invention addresses the issue of tractor clutches controlled by proportional valves. When the driver's intention to move forward or backward is detected, a pressure control strategy based on two pre-charges and time-segmented pressure increases ensures rapid clutch engagement while avoiding poor user experience such as vehicle vibration caused by excessive clutch engagement impact.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a flowchart illustrating the tractor power reversing control method according to Embodiment 1 of the present invention;

[0023] Figure 2 This is a flowchart illustrating the pressure control strategy employed in the tractor power reversal control method according to Embodiment 1 of the present invention.

[0024] Figure 3 These are schematic diagrams of the hardware system for applying the tractor power reversing control method of Embodiment 1 of the present invention and structural schematic diagrams of the tractor power reversing control system of Embodiment 3 of the present invention.

[0025] Figure 4 This is a schematic diagram of the commutation control logic of an example embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the process for obtaining gear change information of a tractor in an example of an embodiment of the present invention;

[0027] Figure 6 This is an example of a pressure regulation diagram used for a proportional valve in an embodiment of the present invention; and

[0028] Figure 7 This is a schematic diagram of the power reversing controller of a tractor according to Embodiment 2 of the present invention. Detailed Implementation

[0029] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0030] Before introducing the solutions of the embodiments of the present invention, some of the terms involved will be introduced first so that those skilled in the art can better understand the solutions of the embodiments of the present invention.

[0031] 1) Gear shift lever: In this embodiment of the invention, it is an FNR lever, which is a reversing control switch installed on the steering column of the tractor (hereinafter also referred to as the vehicle). It is formed by a combination of forward, neutral (N) and reverse (Rear) switches, and has three gears: forward gear (hereinafter also referred to as F gear), neutral gear (hereinafter also referred to as N gear), and reverse gear (hereinafter also referred to as R gear). The neutral gear has a mechanical locking position.

[0032] 2) Electronic clutch pedal: A pedal system used to force the transmission into neutral, and its appearance and operation are consistent with those of the mechanical clutch pedal.

[0033] 3) Electronic clutch: In this embodiment of the invention, it is referred to as clutch. It is located between the engine and the transmission of the vehicle, and transmits the engine power to the transmission. It can disconnect or connect the power transmission between the transmission and the engine as needed, thereby driving the transmission to complete gear shifting.

[0034] 4) TCU: Transmission Control Unit, also known as gearbox control unit or gearbox controller, is a control system that performs command input, decision-making, and signal output for power reversal.

[0035] 5) PID: In process control, a closed-loop controller controls according to the proportional (P), integral (I), and derivative (D) of the deviation. It is a classic control model.

[0036] 6) Kiss-point: The point at which the clearance between the clutch master and driven discs is just eliminated during the reversing process. It can also be understood as the critical point at which the clutch performs the engagement action.

[0037] 7) Sliding wear work: One of the two main indicators of clutch engagement characteristics. A long clutch service life is required, meaning good durability; the most direct factor affecting clutch service life is the friction between the driving and driven friction plates, which increases wear, and this friction can be evaluated using sliding wear work.

[0038] 8) Shock: One of the two main indicators of clutch engagement characteristics. During clutch engagement, the clutch should engage smoothly and gently, meaning there should not be excessive instantaneous acceleration. This avoids generating vibrations and shocks that make passengers feel uncomfortable, as well as excessive loads on the transmission system. These phenomena can be evaluated using shock.

[0039] 9) Power Directional Control Valve Assembly: This includes a forward proportional valve for controlling the engagement and disengagement of the tractor's forward clutch, a reverse proportional valve for controlling the engagement and disengagement of the tractor's reverse clutch, and a neutral switch valve for controlling the supply and disconnection of the clutch assembly's hydraulic circuit. The forward and reverse proportional valves open in response to applied pressure, thereby engaging the corresponding clutches. When the pressure is zero, the forward and reverse proportional valves close, preventing the corresponding clutches from disengaging. The neutral switch valve acts as a master switch for the power directional control valve assembly. When closed, it opens the clutch assembly's hydraulic circuit, allowing further control of the corresponding proportional valves. When the neutral switch valve opens, the clutch assembly's hydraulic circuit is disconnected, the vehicle enters braking mode, and the control of the corresponding proportional valves becomes ineffective.

[0040] 10) Pressure pre-charge: In this embodiment of the invention, pressure pre-charge refers to the clutch engagement preparation stage in which pressure is applied to the proportional valve to open it, thereby actuating the connected clutch to begin filling with oil. That is, the purpose of pressure pre-charge is to ensure that the clutch chamber is filled with oil and pressurized, thus preparing it for the engagement operation.

[0041] 11) Codesys platform: For example, the Codesys V3.5 platform is a powerful PLC software programming tool that can provide TCU with a complete development environment with several functional component modules.

[0042] Example 1

[0043] In the first embodiment of this invention, which addresses the problems of excessive slippage work and impact caused by rapid clutch engagement in current tractor power reversing schemes, a scheme using a proportional valve to control clutch disengagement and engagement is proposed. Furthermore, a proprietary pressure control strategy is proposed for the proportional valve to reduce slippage work and impact during reversing while rapidly disengaging and engaging the clutch.

[0044] Figure 1 This is a flowchart illustrating the tractor power reversing control method according to Embodiment 1 of the present invention. It is applicable to tractors equipped with the aforementioned reversing power valve assembly and may include the following steps:

[0045] Step S100: Obtain the gear change information of the tractor.

[0046] In step S200, when the gear change information indicates that the driver intends to control the tractor to enter forward or reverse gear, the neutral switch valve is closed to open the clutch assembly oil circuit accordingly, and the pressure control strategy of steps S210-S230 is executed for the forward proportional valve or the reverse proportional valve to open the forward proportional valve or the reverse proportional valve and push the corresponding clutch to engage by pressure, thereby driving the tractor's gearbox to switch gears.

[0047] Among them, such as Figure 2 As shown, the pressure control strategy corresponding to steps S210-S230 can be described as follows:

[0048] Step S210: Perform the first pressure pre-charge on the forward proportional valve or the backward proportional valve.

[0049] Step S220: After performing the first pressure pre-charge to the first preset time, perform a second pressure pre-charge on the forward proportional valve or the backward proportional valve.

[0050] The pressure corresponding to the second pressure precharge is less than that of the first pressure precharge.

[0051] Step S230: After performing the second pressure pre-charge to the second preset time, a time-sharing pressure increase control strategy is executed on the forward proportional valve or the reverse proportional valve until the preset maximum pressure is reached to ensure that the corresponding clutches are engaged without slippage.

[0052] The preset maximum pressure can be determined experimentally, or it can be specifically expressed as ensuring that the driving and driven discs of the clutch have sufficient engagement pressure without slippage.

[0053] Furthermore, for step S230, the time-segmented control strategy is configured, for example, as the following three time periods:

[0054] In the first time period, a first pressure is applied to the forward proportional valve or the reverse proportional valve until the corresponding clutch chamber is filled with oil and pressurized and ready to enter the clutch friction plate free travel control stage.

[0055] In the second time period, the pressure applied to the forward proportional valve or the reverse proportional valve is controlled to rise from the first pressure to the second pressure in a ramp manner, which causes the corresponding clutch to reach the critical point for performing the engagement action.

[0056] During the third time period, the pressure applied to the forward proportional valve or the backward proportional valve continues to rise in a ramp manner from the second pressure to the preset maximum pressure.

[0057] Accordingly, the first pressure pre-charge in step S210 uses a larger pressure to drive the relevant proportional valve to open quickly, so as to ensure that the driving pressure to start engagement can be provided to the clutch quickly; while the second pressure pre-charge in step S220 uses a relatively smaller pressure to alleviate the turbulence caused in the first pressure pre-charge; step S230 enters the stage of formally pushing the clutch to engage. In this stage, the proportional valve is subjected to pressure increase control in three time periods as mentioned above, which ensures that the driving and driven plates of the clutch have sufficient engagement pressure without slippage, and also makes the driving pressure on the clutch change slowly to avoid excessive impact when the clutch engages.

[0058] Accordingly, in this embodiment of the invention, for a clutch controlled by a proportional valve, when the driver's intention to move forward or backward is detected, the pressure control strategy shown in steps S210-S230 ensures that the clutch can engage quickly while avoiding poor user experience such as vehicle vibration caused by excessive impact during clutch engagement.

[0059] Furthermore, in a preferred embodiment, for the case where the driver intends to control the tractor to engage forward or reverse gear as described in step S200, the tractor power reversing control method also includes control strategies for other situations, such as steps S300 or S400 below. Figure 1 (Not shown in the image):

[0060] In step S300, when the gear change information indicates that the driver intends to control the tractor to disengage from forward or reverse gear, the pressure applied to the forward proportional valve or the reverse proportional valve is controlled to be zero, so that the forward proportional valve or the reverse proportional valve is closed and the corresponding clutch is disengaged.

[0061] In step S400, when the gear change information indicates that the driver intends to perform emergency braking, the neutral switch valve is opened so that the oil circuit of the clutch assembly is cut off accordingly.

[0062] In a preferred embodiment, to achieve smooth gear shifting, an engine speed control strategy is proposed to be added during gear shifting. More preferably, the engine speed control strategy may include the following steps: when the corresponding clutch is pressure-driven to perform an engagement action, controlling the engine speed to be less than or equal to a preset speed; and after the corresponding clutch is fully engaged, controlling the engine speed in response to the driver's throttle operation.

[0063] The following examples illustrate the specific implementation details of each step.

[0064] In this example, the aforementioned tractor power directional control method is executed by the vehicle's TCU, which is designed using the Codesys platform. The TCU can be configured with two CAN communication ports, 14 inputs, and 10 outputs. The output ports can be configured with current closed-loop control for precise current control. It can also be equipped with a 32-bit high-performance MCU, enabling high-frequency response to various input signals. The hardware interface receives signals including forward, reverse, neutral, and electronic clutch pedal signals. The CAN port receives current engine speed and torque signals. After receiving this information, the TCU performs internal logic calculations to control the power directional valve assembly.

[0065] Therefore, Figure 3 This is a schematic diagram of a hardware system for applying the tractor power reversing control method according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the commutation control logic of an example embodiment of the present invention. Figure 3 As shown, the hardware system includes: TCU, LCD instrument panel, power directional valve assembly, gear shift mechanism (including FRN lever and electronic clutch pedal), and ECU (Engine Control Unit). The TCU collects signals from the FRN lever, ECU, and / or electronic clutch pedal to control the power directional valve assembly, thereby enabling the shifting of forward, neutral, and reverse gears in the transmission. Furthermore, the TCU outputs feedback on the relevant control inputs, outputs, and gear positions via a CAN bus to the LCD instrument panel for display, thus facilitating human-machine interaction and obtaining user commands.

[0066] use Figure 3 The hardware system shown, Figure 4 The example commutation control logic shown may include the following parts.

[0067] I. Vehicle power-on initialization logic.

[0068] For example, when the vehicle is powered on and the engine starts, all controllers perform self-tests normally, confirming the bus connection with the engine is complete and recognizing that the engine has started. The TCU initializes its internal logic and register states upon initial power-up. At this time, the output states of the forward proportional valve, reverse proportional valve, and neutral switch valve are 0, and the transmission is in neutral.

[0069] II. Gear Change Recognition Logic.

[0070] The gear shift recognition logic corresponds to step S100, and as... Figure 5 As shown, the method for obtaining the gear change information of the tractor may include, for example, the following steps:

[0071] Step S110: Obtain the execution status information of the tractor's gear control mechanism.

[0072] For example, based on the execution status of the gear shift mechanism, the driver's intention is identified, and the corresponding logic control program is initiated. The actions of the gear shift mechanism can be summarized in the following ways:

[0073] ①Shift the FRN lever from N to F position;

[0074] ②Shift the FRN lever from neutral (N) to reverse (R);

[0075] ③ Shift the FRN lever from F to N position;

[0076] ④ Shift the FRN lever from R to N position;

[0077] ⑤ Shift the FRN lever from R to F position;

[0078] ⑥ Shift the FRN lever from F to R;

[0079] ⑦ Depress the electronic clutch pedal to less than 50% of its total travel;

[0080] ⑧ Release the electronic clutch pedal.

[0081] Step S120: Obtain the current gear status information of the transmission.

[0082] That is, it can identify whether the current gearbox is in F, R, or N gear.

[0083] Step S130: Combining the execution action status information of the gear shift control mechanism and the current gear status information of the transmission, determine the gear change information that reflects the driver's intention.

[0084] For example, by combining the gear shifting mechanism actions identified in step S110 (①-⑧) with the current F, R, or N gear of the transmission identified in step S120, the following gear shift changes can be determined:

[0085] ① The forward clutch is fully engaged, the reverse clutch is disengaged, and the neutral gear switch valve is closed.

[0086] Currently in drive;

[0087] ② The forward clutch is disengaged, the reverse clutch is fully engaged, and the neutral gear switch valve is closed.

[0088] Currently in reverse gear;

[0089] ③ The forward clutch is disengaged, the reverse clutch is disengaged, the neutral switch valve is closed, and the gear is currently in neutral;

[0090] ④ The forward clutch is disengaged, the reverse clutch is disengaged, the neutral switch valve is open, and the gear is currently in neutral;

[0091] ⑤ During the forward direction clutch engagement, the reverse direction clutch disengages, the neutral switch valve closes, and the current position is in the forward gear engagement process;

[0092] ⑥ During the process of disengaging the forward clutch and engaging the reverse clutch, the neutral switch valve is closed, and the gear is currently in reverse gear.

[0093] Based on this, after identifying the driver's intention, it can be determined that a certain action process or several action processes should be performed on the power directional valve assembly to control the engagement or disengagement of the clutch.

[0094] III. Control Logic of the Power Reversing Valve.

[0095] Depending on the type of power directional valve and the driver's intent identified in the second part above, this part may further include the following components.

[0096] 1. The proportional valve opens.

[0097] In this example, a PID algorithm is used for closed-loop current control of the proportional valve. The opening of the proportional valve engages the clutch, a process that requires both rapid clutch engagement to shorten commutation time and reduce slippage work, and smooth, gentle clutch engagement, meaning there should be no excessive instantaneous acceleration to avoid uncomfortable jerking or shocks for the occupants, as well as excessive load on the transmission system. Therefore, this example employs the aforementioned... Figure 2 The pressure control strategy corresponding to steps S210-S230, and combined with Figure 6 The pressure regulation diagram shown illustrates that the pressure control strategy is further described as follows (where Step 1 corresponds to Step S210, Step 2 corresponds to Step S220, and Steps 3-5 correspond to the first, second, and third time periods of Step S230, respectively):

[0098] Step 1, First pressure pre-charge.

[0099] First, perform an initial pressure pre-charge on the forward or reverse proportional valve, which is equivalent to pre-charging the clutch. The pressure value for this pre-charge should be determined based on the clutch chamber volume, for example, using the maximum allowable pressure of the clutch system. Figure 6 As shown, the default setting is K4, and the precharge time is T1.

[0100] Step 2, second pressure pre-charge.

[0101] After the first pressure precharge reaches a certain stage, a second pressure precharge is performed on the proportional valve at a smaller pressure value to alleviate the turbulence caused during the first pressure precharge process. Figure 6 As shown, the pressure value for the second pressure pre-charge is K1, and the pre-charge time is T2.

[0102] Step 3, pre-charge and boost voltage.

[0103] At this point, the clutch chamber has completed oil filling and pressurization, entering the stage where the clutch officially begins to engage. Figure 6 As shown, pressure control is performed using K2 pressure to prepare for entering the clutch friction plate free travel control stage in order to begin the engagement action.

[0104] Step 4, Free time.

[0105] By using ramp control, the pressure is increased from K2 to K3 within time T4, at which point the critical point for clutch engagement is reached, ultimately achieving the Kiss-point when the clearance between the clutch master and driven plates is just eliminated.

[0106] Step 5: Increase and maintain pressure.

[0107] After Step 4, the clutch master and driven discs are synchronized. At this time, the speed difference between the two is 0. The pressure continues to increase from K3 to K5 after time T5. The pressure is maintained at the preset maximum pressure to ensure that the master and driven discs still have sufficient engagement pressure and do not slip when the load increases.

[0108] Through Step 1-Step 5, the clutch can be engaged quickly to shorten the reversing time and reduce the work done by the slippery plate, while also meeting the requirements for smooth and gentle clutch engagement, which helps to improve the driving experience.

[0109] 2. The proportional valve closes.

[0110] Corresponding to step S300 above, for example, the pressure is directly set to 0 and the valve body is closed.

[0111] 3. Neutral switch valve control.

[0112] Corresponding to step S400 above, for example, when the electronic clutch pedal travel is greater than 50% of the total travel, indicating the driver intends to brake urgently, the neutral switch valve is opened, the clutch assembly oil circuit is cut off, and the return oil port is opened, resulting in emergency pressure relief, thereby achieving clutch disengagement and vehicle inertial braking. Similarly, when the electronic clutch pedal travel is less than 50% of the total travel, the neutral switch valve is closed, the clutch assembly oil circuit is opened and oil is supplied normally, and the vehicle continues to drive normally.

[0113] The neutral gear switch valve is controlled by electronic switching signals. The TCU performs logic calculations based on the electronic clutch pedal travel and other parameters to directly output the corresponding switching signal to open or close the neutral gear switch valve. It should be noted that the application of the neutral gear switch valve indirectly makes the electronic clutch also controllable based on electronic switching signals. Compared with the conventional solution of controlling the electronic clutch based on analog signals, this helps to prevent the clutch from burning out due to manual control of the transmission to a semi-engaged state.

[0114] IV. Engine Speed ​​Control Logic Figure 4 (Not shown).

[0115] Corresponding to the engine speed control strategy described above, it can be specifically described as including the following steps S1-S3:

[0116] S1: During the forward direction clutch engagement process, the engine speed is forcibly limited to no more than N rpm via CAN bus command. After engagement is completed, the foot throttle and hand throttle control rights are restored.

[0117] S2: During the reversing clutch engagement process, the engine speed is forcibly limited to no more than N rpm via CAN bus command. After engagement is completed, the foot throttle and hand throttle control permissions are restored.

[0118] S3: When the electronic clutch pedal is pressed and the neutral switch valve is opened, the engine speed is forced to idle speed via CAN bus command. After the clutch pedal is released and engagement is completed, the foot accelerator and hand accelerator control rights are restored.

[0119] Nrpm is a preset value slightly higher than idle speed. Furthermore, restoring foot and hand throttle control means that the engine speed can be flexibly controlled in response to the driver's throttle input.

[0120] Thus, through steps S1-S3, the oil passage of the clutch can be kept smooth and the shift shock can be reduced, thereby ensuring the smoothness of shifting.

[0121] This example demonstrates that the tractor power reversal control method of Embodiment 1 of the present invention has at least the following advantages:

[0122] 1. A novel pressure control strategy for the clutch proportional valve is presented, which can achieve both rapid clutch disengagement and engagement, and reduce reversing shock.

[0123] 2. In the power reversal control, an engine speed coordinated control strategy was designed to limit the engine speed, which helps to reduce the impact caused by excessive engine speed during clutch engagement and protect the gearbox structure.

[0124] 3. The entire power reversing control does not require the design of pressure sensors, temperature sensors, and speed sensors, which helps to simplify the hardware structure, reduce the hardware failure rate, optimize costs, and facilitate layout and maintenance.

[0125] 4. The tractor power reversing control method can be designed based on the Codesys platform and applied to the TCU, making full use of the advantages of the Codesys platform's fast computing speed and short control response time.

[0126] Example 2

[0127] Figure 7 This is a schematic diagram of the power reversing controller of a tractor according to Embodiment 2 of the present invention. Figure 7 As shown, it may include: a memory storing a program capable of running on a processor; and the processor configured to implement the tractor power reversing control method described in Embodiment 1 when executing the program.

[0128] The power directional control controller can be a general-purpose component. Preferably, the power directional control controller can be the tractor's TCU, and the TCU is configured to run on the Codesys platform. The advantages of the Codesys platform can be found in Embodiment 1 above.

[0129] For more details on the implementation and effects of this power reversing controller, please refer to the aforementioned Embodiment 1, which will not be repeated here.

[0130] Example 3

[0131] Embodiment 3 of the present invention also provides a tractor power reversing control system, the structure of which can be referred to. Figure 3 It includes the following three main parts:

[0132] 1. A gear shifting mechanism, including a gear shift lever and an electronic clutch pedal, wherein the gear shifting mechanism is configured to generate corresponding execution action status information based on the driver's operation of the gear shift lever and the electronic clutch pedal.

[0133] 2. Power directional valve assembly, as described above, includes a forward proportional valve, a reverse proportional valve, and a neutral switch valve.

[0134] 3. The power reversing controller described in Embodiment 2, for example, adopts... Figure 3The TCU shown is configured to: combine the execution action status information obtained from the gear shifting mechanism and the current gear status information of the tractor to generate gear change information reflecting the driver's intention; based on the gear change information, control the operation of the power directional valve assembly to control the engagement, disengagement, or oil circuit opening and closing of the corresponding clutch, thereby driving the tractor's gearbox to perform gear shifting. The specific control strategy for the power directional valve can be found in Embodiment 1, and will not be repeated here.

[0135] In a preferred embodiment, the following interactive device and engine controller may also be included:

[0136] 4. Interactive devices, such as those using Figure 3 The LCD instrument panel communicates with the power commutation controller and is used to interact with the power commutation controller in response to user operations, such as displaying process information to the user or receiving user commands.

[0137] 5. An ECU, which communicates with the power directional control controller, provides the current engine speed to the power directional control controller. Based on this, the power directional control controller sends a speed limiting command to the ECU according to the engagement / disengagement of the corresponding clutches, the on / off status of the oil circuit, and the current engine speed. For the specific execution of the speed limiting command, please refer to Embodiment 1 above.

[0138] For more details on the implementation and effects of the tractor power reversing control system, please refer to Embodiment 1 or Embodiment 2 above, which will not be repeated here.

[0139] Other embodiments of the present invention also provide a machine-readable storage medium storing instructions for causing a machine to execute the tractor power reversing control method of Embodiment 1 described above.

[0140] The machine may be, for example, the aforementioned TCU, or other separately configured controllers. Furthermore, the machine-readable storage medium includes, but is not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, and various other media capable of storing program code.

[0141] For further implementation details and effects of the machine-readable storage medium in the above embodiments, please refer to the corresponding foregoing embodiments, which will not be repeated here.

[0142] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0143] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0144] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0145] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0146] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0147] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0148] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0149] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0150] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0151] It should also be noted that the specific technical features described in the above embodiments can be combined in any suitable manner, without contradiction, such as by exchanging the execution order of some steps. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0152] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A tractor power reversing control method, characterized in that, The tractor is equipped with a forward proportional valve for controlling the engagement and disengagement of the forward clutch, a reverse proportional valve for controlling the engagement and disengagement of the reverse clutch, and a neutral switch valve for controlling the supply and disconnection of the clutch assembly oil circuit. The tractor power reversing control method includes: Obtain the gear shift information of the tractor; and When the gear change information indicates that the driver intends to control the tractor to engage forward or reverse gear, the neutral switch valve is closed to open the clutch assembly oil circuit accordingly. Correspondingly, a pressure control strategy is executed on the forward or reverse proportional valve to open it and engage the corresponding clutch through pressure, thereby driving the tractor's gearbox to shift gears: Perform a first pressure precharge on the forward proportional valve or the reverse proportional valve; After performing the first pressure pre-charge to a first preset time, a second pressure pre-charge is performed on the forward proportional valve or the reverse proportional valve, wherein the pressure corresponding to the second pressure pre-charge is less than that of the first pressure pre-charge; and After performing the second pressure pre-charge to the second preset time, a time-sharing pressure increase control strategy is executed on the forward proportional valve or the reverse proportional valve until the preset maximum pressure that ensures the corresponding clutches are engaged without slippage is reached; The time-segmented boost control strategy includes: In the first time period, a first pressure is applied to the forward proportional valve or the reverse proportional valve until the corresponding clutch chamber is filled with oil and pressurized and ready to enter the clutch friction plate free travel control stage. In the second time period, the pressure applied to the forward proportional valve or the reverse proportional valve is controlled to increase in a ramp manner from the first pressure to a second pressure, which causes the corresponding clutch to reach the critical point for engaging; and During the third time period, the pressure applied to the forward proportional valve or the backward proportional valve continues to rise in a ramp manner from the second pressure to the preset maximum pressure.

2. The tractor power reversing control method according to claim 1, characterized in that, The acquisition of the tractor's gear change information includes: The system acquires the execution status information of the tractor's gear shifting mechanism, wherein the gear shifting mechanism includes a gear shift lever and an electronic clutch pedal; Obtain the current gear status information of the transmission; and By combining the execution action status information of the gear shift control mechanism and the current gear status information of the transmission, the gear change information used to reflect the driver's intention is determined.

3. The tractor power reversing control method according to claim 1, characterized in that, The tractor power reversal control method further includes: When the gear shift information indicates that the driver intends to disengage the tractor from forward or reverse gear, the pressure applied to the corresponding forward proportional valve or reverse proportional valve is reduced to zero, thereby closing the forward proportional valve or reverse proportional valve and disengaging the corresponding clutch; or When the gear change information indicates that the driver intends to perform emergency braking, the neutral switch valve is opened to disconnect the oil circuit of the clutch assembly accordingly.

4. The tractor power reversing control method according to claim 1, characterized in that, The tractor power reversal control method further includes: When the corresponding clutch is engaged by pressure, the engine speed is controlled to be less than or equal to a preset speed; and After the corresponding clutch is fully engaged, the engine speed is controlled in response to the driver's throttle operation.

5. A power reversing controller for a tractor, characterized in that, include: Memory, which stores programs that can run on a processor; as well as The processor is configured to implement the tractor power reversing control method according to any one of claims 1 to 4 when executing the program.

6. The power reversing controller for a tractor according to claim 5, characterized in that, The power reversing controller is the tractor's gearbox controller (TCU), and the TCU is configured to run on the Codesys platform.

7. A tractor power reversing control system, characterized in that, include: The gear shifting mechanism includes a gear shift lever and an electronic clutch pedal, and the gear shifting mechanism is configured to generate corresponding execution action state information based on the driver's operation of the gear shift lever and the electronic clutch pedal; The power directional valve assembly includes a forward proportional valve for controlling the engagement and disengagement of the forward direction clutch of the tractor, a reverse proportional valve for controlling the engagement and disengagement of the reverse direction clutch of the tractor, and a neutral switch valve for controlling the oil supply and disconnection of the clutch assembly of the tractor. The power commutation controller of claim 5 or 6 is configured to: By combining the execution action status information obtained from the gear control mechanism and the current gear status information of the tractor, gear change information reflecting the driver's intention is generated. Based on the gear change information, the power reversing valve assembly is controlled to engage, disengage, or switch the oil circuit of the corresponding clutch, thereby driving the tractor's gearbox to switch gears.

8. The tractor power reversing control system according to claim 7, characterized in that, The tractor power reversing control system also includes: An interactive device that communicates with the power commutation controller and interacts with the power commutation controller in response to user operations.

9. The tractor power reversing control system according to claim 7, characterized in that, The tractor power reversing control system also includes: An engine controller (ECU) communicates with the power commutation controller to provide the current engine speed to the power commutation controller; Furthermore, the power reversing controller is also configured to send a speed limiting command to the ECU based on the engagement, disengagement, or oil circuit status of the corresponding clutch and the current engine speed.

10. A machine-readable storage medium storing instructions for causing a machine to perform the tractor power reversing control method according to any one of claims 1 to 4.

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