Vehicle gear shifting control method and vehicle

Abstract

The invention relates to the technical field of vehicle control, and discloses a vehicle gear shifting control method and a vehicle. A target gear is determined based on a handle gear signal, then acquisition of an accelerator opening signal is shielded, and the target rotating speed of an engine is set to be a preset upshift rotating speed value or a preset downshift rotating speed value; the engine is controlled to output torque based on the target rotating speed, the bypass valve is controlled to be opened, power input of the walking pump to the gearbox is cut off, the gearbox is controlled to be switched to the target gear, after gear shifting is completed, the bypass valve is controlled to be closed, and key transmission components such as the engine, the walking pump and the walking motor are subjected to overall coordination control. The gear shifting operation is completed under the condition that a vehicle is not stopped, operation interruption caused by stopping and gear shifting in a traditional transmission system is avoided, and therefore the operation efficiency and the working condition adaptability are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, specifically to a vehicle shifting control method and a vehicle. Background Technology

[0002] Existing all-terrain vehicles have significant limitations in their gear shifting mechanisms. Gear shifting must be performed when the vehicle is stationary to avoid damaging the gearbox. This prevents the vehicle from adjusting its power output in real time according to changes in terrain while driving, resulting in work interruptions and reduced overall work efficiency. Summary of the Invention

[0003] This invention provides a vehicle shifting control method and a vehicle to solve the problem that shifting operations must be performed when the vehicle is stationary, which prevents the vehicle from adjusting its power output in real time according to changes in terrain during operation, thus causing work interruptions.

[0004] In a first aspect, the present invention provides a vehicle shift control method, applied to a controller in a vehicle shift control system. The vehicle shift control system further includes an engine, a travel pump, a travel motor, a bypass valve, and a transmission. The engine drives the travel pump, the hydraulic oil generated by the travel pump drives the travel motor, and the travel motor transmits power to the transmission. The bypass valve is connected in the hydraulic output circuit of the travel pump to control the flow path of the hydraulic oil output by the travel pump. The method includes: acquiring a gear position signal from a gear lever; determining a target gear based on the gear position signal; blocking the acquisition of a throttle opening signal and setting a first target engine speed to a preset upshift or downshift speed value to control the engine to output torque based on the first target speed; controlling the bypass valve to open to cut off the power input from the travel pump to the transmission; controlling the transmission to switch to the target gear; and controlling the bypass valve to close after the shift operation is completed.

[0005] The vehicle shifting control method provided by this invention determines the target gear based on the gear lever signal emitted by the gear lever, then blocks the acquisition of the throttle opening signal, and sets the first target engine speed to a preset upshift or downshift speed value to control the engine to output torque based on the first target speed. At the same time, it controls the bypass valve to open to cut off the power input of the travel pump to the transmission, and the transmission switches to the target gear. After the shifting operation is completed, it controls the bypass valve to close. By coordinating and controlling key transmission components such as the engine, travel pump, and travel motor, the vehicle can complete the shifting operation without stopping, avoiding the work interruption caused by stopping to shift gears in traditional transmission systems, thereby greatly improving work efficiency and adaptability to working conditions.

[0006] In one optional implementation, determining the target gear based on the handle gear position signal includes: acquiring the gear position mode of the manual / automatic mode switch; determining the currently allowed highest gear based on the handle gear position signal; if the current gear position mode is automatic mode, acquiring the current vehicle speed; using the currently allowed highest gear as a constraint, determining the target gear based on a comparison between the current vehicle speed and preset upshift speed thresholds and downshift speed thresholds corresponding to each gear.

[0007] This invention sets the highest gear constraint by using a lever and dynamically determines the gear based on vehicle speed, replacing the driver's subjective judgment. This avoids misjudging operating conditions and causing unreasonable gear selection, ensuring that the gear policy is accurately matched with actual driving conditions, and improving the stability and reliability of driving performance.

[0008] In one optional implementation, determining the target gear based on a comparison between the current vehicle speed and preset upshift and downshift speed thresholds corresponding to each gear includes: determining the target gear based on a comparison between the current vehicle speed and preset upshift and downshift speed thresholds corresponding to each gear includes: when the current vehicle speed is greater than the upshift speed threshold corresponding to the first gear, determining the second gear as the target gear, wherein the second gear is the adjacent higher gear of the first gear; or, when the current vehicle speed is less than the downshift speed threshold corresponding to the second gear, determining the first gear as the target gear; or, when the current vehicle speed is greater than the downshift speed threshold corresponding to the second gear and less than the upshift speed threshold corresponding to the first gear, determining the current gear as the target gear.

[0009] This invention creates a dedicated buffer zone by setting an upshift speed threshold greater than a downshift speed threshold. When the vehicle speed is within this zone, the system maintains the current gear without switching, avoiding frequent gear changes and significantly improving driving comfort. It also accurately matches vehicle speed and gear, optimizing vehicle power and fuel economy.

[0010] In an optional implementation, the method further includes: if the current gear mode is manual mode, determining the currently allowed highest gear as the target gear; if the current gearbox gear is greater than the target gear and the current vehicle speed is higher than the feedforward protection preset value, determining the current gearbox gear as the target gear.

[0011] In manual mode, this invention directly determines the target gear position by the lever position signal, fully following the driver's active shifting intentions and meeting the driver's precise control needs. Furthermore, when the current gearbox gear is higher than the highest gear and the current vehicle speed is higher than the feedforward protection preset value, the feedforward protection maintains the current gear position, avoiding high-risk shifting, protecting the power system and driving safety, and improving driving smoothness and power continuity.

[0012] In one optional implementation, controlling the transmission to switch to the target gear and controlling the bypass valve to close after the gear shifting operation is completed includes: calculating the pressure difference between the oil ports on both sides of the travel pump; when the pressure difference is less than a preset difference threshold, controlling the solenoid valve corresponding to the current gear on the transmission to deactivate and start timing; when the first timing duration reaches a first preset duration threshold, controlling the solenoid valve corresponding to the target gear to enable; and after the gear shifting operation is completed, closing the bypass valve based on a preset bypass valve shut-off curve.

[0013] This invention, after disabling the current gear solenoid valve, waits a certain period of time to ensure that the current gear is completely disengaged before enabling the solenoid valve corresponding to the target gear. This avoids overlapping conflicts in the oil circuit, protects the solenoid valve and the hydraulic system, and can slowly close the bypass valve according to the preset bypass valve shut-off curve, thereby effectively suppressing the impact on the vehicle caused by the gear shifting process.

[0014] In an optional implementation, the method further includes: starting a timer when the target engine speed is set to a preset upshift speed value or downshift speed value, and detecting the on / off state of the bypass valve in real time; when the second timer duration reaches a second preset time threshold and the bypass valve is in the open state, determining that the gear shift has failed, and maintaining the current gear of the transmission.

[0015] In one optional implementation, after the vehicle gear shifting operation is completed, the method further includes: acquiring a throttle opening signal; calculating a second target engine speed based on the throttle opening signal; generating a pulse control signal of a corresponding frequency based on the difference between the second target speed and the current engine speed to adjust the engine speed; acquiring a gear position direction signal of the gear lever and the current vehicle speed; determining a first target displacement of the travel pump based on the adjusted current engine speed, and setting the output direction of the travel pump to the gear position direction; and determining a second target displacement of the travel motor based on the current vehicle speed.

[0016] In an optional embodiment, the method further includes: acquiring a brake pedal opening signal; determining a third target displacement of the travel pump based on the opening signal, wherein the opening signal and the third target displacement are inversely proportional; updating the first target displacement to the third target displacement if the first target displacement is not less than the third target displacement; determining whether the absolute value of the first rate of change of the first target displacement exceeds a preset first slope threshold during the process of controlling the travel pump based on the first target displacement; adjusting the first rate of change of the first target displacement to the slope threshold if the absolute value of the first rate of change of the first target displacement exceeds the preset first slope threshold during the process of controlling the travel motor based on the second target displacement; and determining whether the absolute value of the second rate of change of the second target displacement exceeds a preset second slope threshold during the process of controlling the travel motor based on the second target displacement; adjusting the second rate of change of the second target displacement to the second slope threshold if the absolute value of the second rate of change of the second target displacement exceeds the preset second slope threshold during the process of controlling the travel motor based on the second target displacement.

[0017] This invention is based on a closed-loop coordinated control logic of throttle, speed and travel pump, which ensures speed stability and control accuracy, and the power response is accurately adapted to the driving intention, thereby improving operational flexibility.

[0018] In an optional implementation, the method further includes: acquiring a first voltage signal and a second voltage signal output from the accelerator pedal; dividing the first voltage signal by a preset value to obtain a first quotient; calculating the absolute value of the difference between the first quotient and the second voltage signal, and placing the absolute value of the difference in the first voltage signal to obtain the throttle synchronization deviation; if the throttle synchronization deviation is not less than a preset deviation threshold, then setting the throttle opening signal to zero.

[0019] Secondly, the present invention provides a vehicle including a vehicle shift control system. The vehicle shift control system includes a controller, an engine, a travel pump, a travel motor, a bypass valve, and a gearbox. The engine drives the travel pump, the hydraulic oil generated by the travel pump drives the travel motor, and the travel motor transmits power to the gearbox. The bypass valve is connected in the hydraulic output circuit of the travel pump to control the flow path of the hydraulic oil output by the travel pump. The controller includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the vehicle shift control method of the first aspect or any corresponding embodiment described above. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a structural example diagram of a vehicle shift control system according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a first method for controlling vehicle gear shifting according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating vehicle gear shift control according to an embodiment of the present invention; Figure 4 This is a second flowchart illustrating a vehicle shift control method according to an embodiment of the present invention; Figure 5 This is a flowchart illustrating the determination of the target gear according to an embodiment of the present invention; Figure 6 This is a flowchart illustrating the normal driving and non-stop gear shifting of a vehicle according to an embodiment of the present invention; Figure 7 This is a structural block diagram of a vehicle according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the hardware structure of the vehicle controller according to an embodiment of the present invention.

[0022] In the diagram, the components are: gear shift lever 1, pressure sensor 2, engine speed sensor 3, vehicle speed sensor 4, accelerator pedal 5, brake pedal 6, manual / automatic mode switch 7, vehicle controller 8, stepper motor 9, engine 10, travel pump 11, travel motor 12, gearbox 13, and drive axle 14. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] As a type of off-road vehicle, all-terrain vehicles (ATVs) can freely travel on complex terrains that are difficult for ordinary vehicles to traverse. Existing ATV transmission systems mostly employ a combination of hydrostatic systems and gearboxes, which can output significant torque at low speeds and exhibit a clear efficiency advantage at medium and low speeds. However, to avoid damaging the gearbox during gear shifts, the shifting operation usually needs to be completed when the vehicle is stationary. This prevents the vehicle from adjusting its power output in real time according to changes in terrain while in motion, leading to work interruptions and reduced overall work efficiency. Furthermore, this system relies on the driver's subjective judgment of the operating conditions for gear shifting; if the judgment is incorrect, it may result in insufficient low-torque output or failure to reach the expected speed, affecting the vehicle's driving performance.

[0026] According to an embodiment of the present invention, a vehicle shift control method embodiment is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0027] This embodiment provides a vehicle shift control method, which can be used in the controller of a vehicle shift control system. The vehicle shift control system also includes an engine, a travel pump, a travel motor, a bypass valve, and a transmission. The engine drives the travel pump, the hydraulic oil generated by the travel pump drives the travel motor, the travel motor transmits power to the transmission, and the bypass valve is connected to the hydraulic output circuit of the travel pump to control the flow path of the hydraulic oil output by the travel pump. Specifically, as shown... Figure 1As shown, the vehicle shift control system includes a gear lever 1, a pressure sensor 2, an engine speed sensor 3, a vehicle speed sensor 4, an accelerator pedal 5, a brake pedal 6, a manual / automatic mode switch 7, a vehicle controller 8, a stepper motor 9, an engine 10, a travel pump 11, a travel motor 12, a gearbox 13, and a drive axle 14. The vehicle controller 8, as the core control unit, can analyze the driver's operating intentions by collecting signals from the gear lever 1, the manual / automatic mode switch 7, the accelerator pedal 5, and the brake pedal 6. Simultaneously, it can integrate the pressure signals from the engine speed sensor 3, the vehicle speed sensor 4, and the travel pump 11 to control the engine 10 and the hydrostatic system. The system (including the travel pump 11 and travel motor 12) precisely controls the displacement of the transmission and the gear position of the gearbox 13. The travel pump 11 is also equipped with a bypass valve, which is connected to the hydraulic output circuit of the travel pump to control the flow path of the hydraulic oil output by the travel pump 11. This control method ensures that the vehicle can complete the gear shifting operation without stopping during driving, thereby maintaining continuous power output. Under normal driving conditions, the gearbox 13 transmits the power of the travel motor 12 to the drive axle 14, which ultimately drives the wheels, achieving smooth driving of the entire vehicle. This invention adopts a hydrostatic transmission system, giving full play to its efficiency advantages in low and medium speed conditions, and effectively expanding the high-efficiency working range of the vehicle.

[0028] Figure 2 This is a flowchart of a vehicle shift control method according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps: Step S201: Obtain the gear position signal emitted by the gear lever and determine the target gear based on the gear position signal.

[0029] The controller in this embodiment of the invention can read the gear position signal emitted by the gear lever 1, and then determine the target gear for this gear shift based on the gear position signal. For example, if the gear position signal indicates a shift from D1 to D2, then the target gear is determined to be D2. This is just an example.

[0030] In step S202, the acquisition of the throttle opening signal is blocked, and the first target speed of the engine is set to a preset upshift speed value or downshift speed value, so as to control the engine to output torque based on the first target speed.

[0031] In this embodiment of the invention, if the target gear is determined to be different from the current gear, a gear shift operation can be performed. To avoid shock caused by mismatch between engine speed and transmission speed 13 during gear shifting, i.e., to ensure smooth operation of non-stop gear shifting, dynamic intervention can be performed on engine speed. The acquisition of throttle opening signal is blocked, and the accelerator pedal input is temporarily not responded to. The first target speed of engine 10 is set to a pre-calibrated upshift or downshift speed value. Subsequently, engine 10 can be controlled to output stable torque based on the first target speed, preparing for speed synchronization during gear shifting and avoiding power interruption. Specifically, when transmission 13 performs an upshift, the engine speed needs to decrease accordingly. The first target speed can be set... The upshift speed value can be calibrated based on the target gear and the current speed. For example, different upshift speed values ​​can be calibrated for different gears. Generally, the upshift speed value is lower than the current speed corresponding to the gear. When the transmission 13 performs a downshift, the engine speed needs to increase accordingly. The first target speed can be set as the downshift speed value. The downshift speed value can also be calibrated based on the target gear and the current speed. For example, different downshift speed values ​​can be calibrated for different gears. Generally, the downshift speed value is higher than the current speed corresponding to the gear. This is just an example. After the gear shift is completed, the controller can continue to acquire the throttle opening signal and determine the target speed based on the throttle opening signal for closed-loop control.

[0032] In step S203, the bypass valve is opened to cut off the power input from the travel pump to the gearbox.

[0033] Specifically, the travel pump 11 integrates two oil ports (usually marked as port A and port B). Ports A and B are directly connected to the corresponding two oil ports of the travel motor 12 via high-pressure hoses, so that the travel pump 11, the travel motor 12, and the connecting pipeline form a closed oil circulation loop. The bypass valve is usually an electromagnetic control valve that is connected between ports A and B of the travel pump 11. When the bypass valve is closed, ports A and B are isolated, the high-pressure oil circuit is established, and the oil circulation loop is open. When the bypass valve is open, the hydraulic oil output by the travel pump 11 flows directly between ports A and B through the bypass valve, and the hydraulic oil does not flow to the travel motor 12, and therefore does not input power to the gearbox 13.

[0034] like Figure 3 As shown, in this embodiment of the invention, during gear shifting, a bypass valve can be opened, which will cut off the power input of the gearbox 13, thereby effectively preventing damage to the gear shifting gears during gear shifting.

[0035] Step S204: Control the transmission to switch to the target gear.

[0036] The embodiments of the present invention do not limit the specific method of controlling the gear shifting of the transmission. For example, the automatic transmission is driven by hydraulics and controlled by planetary gear sets. Gear shifting is achieved by different combinations of planetary gear sets. It can also drive the shift fork to engage the target gear. This is only an example and is based on the actual transmission principle design.

[0037] Step S205: After the gear shifting operation is completed, control the bypass valve to close.

[0038] In this embodiment of the invention, after the gear shifting operation is completed, the controller can control the bypass valve to close.

[0039] The vehicle shift control method provided by this invention determines the target gear based on the gear position signal emitted by the gear lever 1, then blocks the acquisition of the throttle opening signal, and sets the first target speed of the engine 10 to a preset upshift or downshift speed value to control the engine 10 to output torque based on the first target speed. At the same time, it controls the bypass valve to open to cut off the power input of the travel pump 11 to the gearbox 13, and controls the gearbox 13 to switch to the target gear. After the shift operation is completed, it controls the bypass valve to close. By coordinating and controlling key transmission components such as the engine 10, travel pump 11 and travel motor 12, the vehicle can complete the shift operation without stopping, avoiding the work interruption caused by stopping to shift gears in traditional transmission systems, thereby greatly improving work efficiency and adaptability to working conditions.

[0040] This embodiment provides a vehicle shift control method, which can be used in the vehicle controller 8 of a vehicle shift control system. Figure 4 This is a flowchart of a vehicle shift control method according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps: Step S401: Obtain the gear position signal emitted by the gear lever and determine the target gear based on the gear position signal.

[0041] Specifically, step S401 above includes: Step S4011: Obtain the gear mode of the manual / automatic mode switch.

[0042] Step S4012: Determine the highest allowed gear based on the handle gear signal.

[0043] Step S4013: If the current gear mode is automatic, obtain the current vehicle speed.

[0044] Step S4014: Using the currently allowed highest gear as a constraint, determine the target gear based on the comparison between the current vehicle speed and the preset upshift speed threshold and downshift speed threshold corresponding to each gear.

[0045] In this embodiment of the invention, the gear position signal emitted by the gear lever 1 is read and determined as the highest allowed gear. Simultaneously, the current gear mode of the manual / automatic mode switch 7 can be obtained via the CAN bus. If the current gear mode is automatic, vehicle speed-linked gear shifting can be triggered to obtain the current vehicle speed. Under the constraint of the highest gear, the current vehicle speed is compared with preset upshift and downshift speed thresholds corresponding to each gear to determine the target gear. Specifically, the upshift speed thresholds corresponding to each gear are pre-calibrated. (For example, the speed threshold for shifting from D1 to D2 is 12 km / h, meaning the upshift speed threshold for the first gear is 12 km / h) and the downshift speed threshold (the speed threshold for shifting from D2 to D1 is below 10 km / h, meaning the downshift speed threshold for the second gear is 10 km / h). If the current speed reaches the upshift threshold of a higher gear, and the higher gear does not exceed the highest allowed gear, then the target gear is set to that higher gear. If the current speed is below the downshift threshold of the current gear, then the target gear is set to a lower gear. This is just an example.

[0046] This invention sets the highest gear constraint by using a lever and dynamically determines the gear based on vehicle speed, replacing the driver's subjective judgment. This avoids misjudging operating conditions and causing unreasonable gear selection, ensuring that the gear policy is accurately matched with actual driving conditions, and improving the stability and reliability of driving performance.

[0047] Furthermore, when the current vehicle speed is greater than the upshift speed threshold corresponding to the first gear, the second gear is determined as the target gear, wherein the second gear is the adjacent higher gear of the first gear; or, when the current vehicle speed is less than the downshift speed threshold corresponding to the second gear, the first gear is determined as the target gear; or, when the current vehicle speed is greater than the downshift speed threshold corresponding to the second gear and less than the upshift speed threshold corresponding to the first gear, the current gear is determined as the target gear.

[0048] In this embodiment of the invention, the acquired lever gear position signal is taken as the currently operating highest gear, and the vehicle speed is compared with the upshift / downshift speed thresholds corresponding to each gear. When the current vehicle speed is greater than the upshift speed threshold corresponding to the first gear, an upshift is triggered. For example, if the vehicle speed is 13 km / h and reaches the upshift speed threshold corresponding to gear D1, the gear is shifted from D1 to D2, and the second gear is determined as the target gear. When the current vehicle speed is lower than the downshift speed threshold corresponding to the second gear, the first gear is determined as the target gear. For example, if the vehicle speed drops to 9 km / h and is lower than the downshift speed threshold corresponding to gear D2, the gear is downshifted from D2 to D1. When the current vehicle speed is greater than the downshift speed threshold corresponding to the second gear and less than the upshift speed threshold corresponding to the first gear, the current gear is determined as the target gear. For example, if the vehicle speed is maintained between 10 and 12 km / h, the current gear is maintained to avoid frequent shifting.

[0049] In specific embodiments, such as Figure 5As shown, when the lever gear position signal is in neutral, the highest gear is also in neutral, and the target gear is also in neutral. Taking the highest lever gear as second gear as an example, when the lever gear is in second gear, the currently allowed highest gear is also second gear. In automatic mode, it is determined whether the vehicle speed is higher than the upshift speed threshold corresponding to each gear. If the current vehicle speed exceeds the upshift speed threshold corresponding to first gear, the target gear is set to second gear. If the current vehicle speed is lower than the downshift speed threshold corresponding to second gear, the target gear is set to first gear. This is just an example.

[0050] This invention creates a dedicated buffer zone by setting an upshift speed threshold greater than a downshift speed threshold. When the vehicle speed is within this zone, the system maintains the current gear without switching, avoiding frequent gear changes and significantly improving driving comfort. It also accurately matches vehicle speed and gear, optimizing vehicle power and fuel economy.

[0051] In one alternative implementation, if the current gear mode is manual mode, the highest allowed gear is determined as the target gear.

[0052] When the current gear mode of the manual mode switch 7 obtained in this embodiment of the invention is manual mode, the gear position signal output by the gear position handle 1 can be directly determined as the target gear position.

[0053] In manual mode, this invention directly determines the gear position signal of the lever as the target gear, fully following the driver's active gear shifting intention and meeting the driver's precise control needs.

[0054] In one alternative implementation, if the current gearbox gear is greater than the highest allowed gear and the current vehicle speed is higher than the feedforward (FF) protection preset value, the current gearbox gear is determined as the target gear.

[0055] In this embodiment of the invention, the read gear position signal of the gear lever is determined as the highest allowed gear. If the current gear 13 of the transmission is greater than the highest allowed gear and the current vehicle speed is higher than the feedforward protection preset value, then the feedforward protection is enabled to maintain the current gear 13 of the transmission.

[0056] When the current gearbox 13 is higher than the highest gear and the current vehicle speed is higher than the feedforward protection preset value, the present invention maintains the current gear through feedforward protection to avoid high-risk gear shifting, protect the power system and driving safety, and improve driving smoothness and power continuity.

[0057] Step S402: The acquisition of the throttle opening signal is disabled, and the engine's first target speed is set to a preset upshift or downshift speed value to control the engine's torque output based on the first target speed. For details, please refer to [link to details]. Figure 2 Step S202 of the illustrated embodiment will not be described again here.

[0058] Step S403: The bypass valve is opened to cut off the power input from the travel pump to the gearbox. For details, please refer to [link to relevant documentation]. Figure 2 Step S203 of the illustrated embodiment will not be described again here.

[0059] Step S404: Control the transmission to switch to the target gear.

[0060] Specifically, the pressure difference between the oil ports on both sides of the travel pump is calculated; when the pressure difference is less than a preset difference threshold, the solenoid valve corresponding to the current gear on the gearbox is deactivated and a timer is started; when the first timer duration reaches the first preset duration threshold, the solenoid valve corresponding to the target gear is enabled.

[0061] The controller in this embodiment of the invention can collect pressure values ​​in real time through pressure sensors 2 installed on both sides of the travel pump 11 and calculate the pressure difference between the two sides of the oil ports. When the pressure difference is detected to be less than a preset difference threshold, it is determined that the current shifting condition is met. First, the solenoid valve corresponding to the current gear on the transmission 13 can be disabled. After the solenoid valve corresponding to the current gear on the transmission 13 is disabled, a timer is started. After waiting for a first preset time threshold, the solenoid valve of the target gear on the transmission 13 is enabled. The setting of the first preset time threshold is not limited and can be set according to the actual vehicle system design. For example, 500ms is used.

[0062] This invention, after disabling the solenoid valve of the current gear, waits for a certain period of time to ensure that the current gear is completely disengaged before enabling the solenoid valve corresponding to the target gear, thus avoiding overlapping conflicts in the oil circuit and protecting the solenoid valve and the hydraulic system.

[0063] Step S405: After the gear shifting operation is completed, control the bypass valve to close.

[0064] Specifically, based on the preset bypass valve shut-off curve, the bypass valve is closed. In the power transmission path of the system, the engine 10 provides the original power to the travel pump 11, and the travel pump 11 outputs the power to the travel motor 12 in the form of hydraulic oil. The travel motor 12 converts the hydraulic energy back into mechanical energy and transmits it to the gearbox 13. After the gearbox 13 adjusts the speed and torque, the power is finally transmitted to the wheels through the drive axle 14.

[0065] The present invention can slowly close the bypass valve according to a preset bypass valve shut-off curve, thereby effectively suppressing the impact on the vehicle during the gear shifting process.

[0066] In one optional implementation, when the target speed of the engine 10 is set to a preset upshift speed value or downshift speed value, timing begins and the on / off state of the bypass valve is detected in real time; when the second timing duration reaches the second preset duration threshold and the bypass valve is in the open state, it is determined that the gear shift has failed and the current gear of the transmission 13 is maintained.

[0067] like Figure 3 As shown, the embodiment of the present invention can accumulate the shift time and detect the opening and closing status of the bypass valve in real time. Only when the bypass valve changes from the open state to the closed state is the shift determined to be over. If the shift time exceeds the preset time threshold, it indicates that the shift has failed and the current gear of the transmission 13 can be maintained.

[0068] In one optional implementation, during normal vehicle operation, the engine speed is adjusted based on the throttle opening so that the engine 10 performs closed-loop driving control based on the adjusted speed. Specifically, the throttle opening signal is acquired; based on the throttle opening signal, a second target speed of the engine 10 is calculated; based on the difference between the second target speed and the current engine speed, a pulse control signal of corresponding frequency is generated to adjust the engine speed; the gear position direction signal of the gear lever 1 is acquired; based on the adjusted current engine speed, a first target displacement of the travel pump 11 is determined, and the output direction of the travel pump 11 is set to the gear position direction.

[0069] like Figure 6 As shown, in this embodiment of the invention, during normal driving, the opening signal of the accelerator pedal 5 can be acquired, and the second target speed of the engine 10 can be determined based on the accelerator pedal opening signal. The speed adjustment method can be based on a preset accelerator pedal opening-speed mapping curve to determine the second target speed of the engine 10, without limitation. Then, the current speed of the engine 10 can be calculated by collecting the frequency value of the engine speed sensor 3, and the speed difference between the second target speed and the current engine speed can be calculated. If the speed difference is less than a preset speed adjustment threshold, the stepper motor 9 remains stationary, and the engine speed remains unchanged. If the speed difference is greater than the preset speed adjustment threshold... Adjusting the threshold, the speed difference is input into a preset software algorithm for calculation, generating pulse control signals of different frequencies to drive the stepper motor 9. The software algorithm can be a closed-loop control algorithm (Proportional-Integral-Derivative, PID). The pulse signals of different frequencies drive the stepper motor 9 to rotate, and the rotational motion is converted into linear motion of the lead screw nut through the lead screw structure. The lead screw nut fixes the push rod, and the end of the push rod is fixed to the throttle cable. At this time, the tension and relaxation of the throttle cable of the engine 10 can be adjusted by controlling the rotation of the stepper motor 9, thereby changing the engine speed.

[0070] In this embodiment of the invention, the gear position direction signal of the gear lever 1 and the engine speed can be read, and the first target displacement of the travel pump 11 can be determined according to the mapping curve between the current engine speed and the target displacement. The gear position direction signal can then be determined as the output direction of the travel pump 11 to avoid power transmission conflicts. The operation of the travel pump 11 can then be controlled by the displacement adjustment signal of the travel pump 11.

[0071] This invention is based on the closed-loop coordinated control logic of throttle-speed and travel pump 11, which ensures speed stability and control accuracy, and the power response is accurately adapted to the driving intention, thereby improving operational flexibility.

[0072] Furthermore, the target displacement of the travel pump 11 can be subjected to secondary limiting and smoothing processing. Specifically, the opening signal of the brake pedal 6 is acquired; the third target displacement of the travel pump 11 is determined based on the opening signal, wherein the opening signal and the third target displacement are inversely proportional; if the first target displacement is not less than the third target displacement, the first target displacement is updated to the third target displacement; during the process of controlling the operation of the travel pump 11 based on the first target displacement, it is determined whether the absolute value of the first rate of change of the first target displacement exceeds the preset first slope threshold; if the absolute value of the first rate of change of the first target displacement exceeds the preset first slope threshold, the first rate of change of the first target displacement is adjusted to the slope threshold.

[0073] In addition to braking the drive axle 14 hydraulically, the brake pedal 6 designed in this embodiment of the invention can also limit the target displacement of the travel pump 11 through the opening signal of the brake pedal 6. Specifically, the brake pedal 6 and the target displacement are inversely proportional. When the brake pedal 6 is fully depressed, the target displacement of the travel pump 11 is at its minimum. The third target displacement of the travel pump 11 can be determined based on the opening signal of the brake pedal 6. If the first target displacement is not less than the third target displacement, the first target displacement is updated to the third target displacement, thereby achieving proportional limiting of the target displacement of the travel pump 11. During the output process, the target displacement of the travel pump 11 is smoothed by the displacement slope curve. If the absolute value of the first rate of change of the first target displacement (e.g., the growth or decline slope) exceeds the first slope threshold, the first rate of change is adjusted to the slope threshold to avoid impact.

[0074] This invention significantly improves the smoothness of vehicle operation and the continuity of dynamic response during driving by performing secondary limiting and smoothing processing on the target displacement of the walking pump 11.

[0075] Furthermore, the current vehicle speed can be obtained, and based on the current vehicle speed, the second target displacement of the travel motor 12 can be determined. During the process of controlling the travel motor 12 to work based on the second target displacement, it is determined whether the absolute value of the second rate of change of the second target displacement exceeds the preset second slope threshold. If the absolute value of the second rate of change of the second target displacement exceeds the preset second slope threshold, the second rate of change of the second target displacement is adjusted to the second slope threshold.

[0076] like Figure 6As shown, in this embodiment of the invention, the current vehicle speed can be calculated by the frequency value of the vehicle speed sensor 4. Then, based on the current vehicle speed as input, the second target displacement of the walking motor 12 is determined according to the mapping curve between vehicle speed and displacement. During the process of controlling the walking motor 12 to work based on the second target displacement, the output displacement will be smoothed by the displacement slope curve. If the increase or decrease slope exceeds the threshold, the second rate of change will be adjusted to the slope threshold to avoid impact.

[0077] This invention significantly improves the smoothness of vehicle operation and the continuity of dynamic response during driving by performing secondary amplitude limiting and smoothing processing on the target displacement of the walking motor 12.

[0078] Specifically, the throttle opening signal is obtained through the following steps: acquiring the first voltage signal and the second voltage signal output by the throttle pedal 5; calculating the first opening based on the first voltage signal, the minimum value and the maximum value of the first voltage signal; calculating the second opening based on the second voltage signal, the minimum value and the maximum value of the second voltage signal; and calculating the average value of the first opening and the second opening as the throttle opening.

[0079] This invention can acquire the first voltage signal APS1 and the second voltage signal APS2 output from the accelerator pedal 5, and then calculate the throttle opening using the following formula:

[0080] in, Indicates the first opening degree; This represents the minimum value of the first voltage signal; This indicates the maximum value of the first voltage signal.

[0081]

[0082] in, Indicates the second opening degree; This indicates the minimum value of the second voltage signal; This indicates the maximum value of the second voltage signal.

[0083]

[0084] OP represents the throttle opening.

[0085] Furthermore, it is necessary to determine whether the throttle synchronization deviation meets the conditions. The first voltage signal is divided by a preset value to obtain the first quotient. The absolute value of the difference between the first quotient and the second voltage signal is calculated, and the absolute value of the difference is placed in the first voltage signal to obtain the throttle synchronization deviation. If the throttle synchronization deviation is not less than the preset deviation threshold, the throttle opening signal is set to zero.

[0086] The embodiments of the present invention calculate the throttle synchronization deviation through the following steps:

[0087] in, This indicates throttle synchronization deviation, with a deviation threshold set to 1%, for illustrative purposes only.

[0088] If the throttle synchronization deviation is determined to be not less than a preset deviation threshold, and the throttle pedal 5 is found to be faulty, the throttle opening can be set to zero, the engine 10 can be controlled to idle speed, and an alarm can be issued.

[0089] This invention determines abnormalities in the accelerator pedal 5 by detecting throttle synchronization deviation, which can accurately identify whether the throttle signal is abnormal, avoid driving risks, and ensure the accuracy of power control.

[0090] This embodiment also provides a vehicle, such as Figure 7 As shown, the vehicle includes a vehicle shift control system 71, which includes a controller, an engine 10, a travel pump 11, a travel motor 12, a bypass valve, and a gearbox 13. The engine 10 drives the travel pump 11, and the hydraulic oil generated by the travel pump 11 drives the travel motor 12. The travel motor 12 transmits power to the gearbox 13. The bypass valve is connected to the hydraulic output circuit of the travel pump 11 to control the flow path of the hydraulic oil output by the travel pump 11. The controller includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the vehicle shift control method described above. For detailed description, please refer to the above embodiment, which will not be repeated here.

[0091] Specifically, the vehicle is an all-terrain vehicle.

[0092] Figure 8 This is a schematic diagram of the structure of the vehicle controller in a vehicle shift control system provided in an embodiment of the present invention.

[0093] The following is a detailed reference. Figure 8 The diagram illustrates a structural schematic suitable for implementing a vehicle controller according to an embodiment of the present invention. The vehicle controller may include a processor (e.g., a central processing unit, a graphics processing unit, etc.) 801, which can perform various appropriate actions and processes based on a program stored in a read-only memory (ROM) 802 or a program loaded from a memory 808 into a random access memory (RAM) 803. The RAM 803 also stores various programs and data required for the operation of the vehicle controller. The processor 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0094] Typically, the following devices can be connected to I / O interface 805: input devices 806 including, for example, a touchscreen, touchpad, keyboard, mouse, camera, microphone, accelerometer, gyroscope, etc.; output devices 807 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; memory 808 including, for example, magnetic tape, hard disk, etc.; and communication devices 809. Communication device 809 allows the vehicle controller to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 8 The vehicle controller shown has various devices; however, it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0095] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 809, or installed from a memory 808, or installed from a ROM 802. When the computer program is executed by the processor 801, it performs the functions defined in the vehicle shift control method of the embodiments of the present invention.

[0096] Figure 8 The vehicle controller shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0097] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the vehicle shift control method shown in the above embodiments is implemented.

[0098] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0099] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A vehicle gear shifting control method, characterized in that, A controller is applied in a vehicle shift control system, the vehicle shift control system further including an engine, a travel pump, a travel motor, a bypass valve, and a transmission. The engine drives the travel pump, the hydraulic oil generated by the travel pump drives the travel motor, the travel motor transmits power to the transmission, and the bypass valve is connected in the hydraulic output circuit of the travel pump to control the flow path of the hydraulic oil output by the travel pump. The method includes: Obtain the gear position signal emitted by the gear lever, and determine the target gear position based on the gear lever signal; The acquisition of throttle opening signal is blocked, and the first target speed of the engine is set to a preset upshift speed value or downshift speed value, so as to control the engine to output torque based on the first target speed; The bypass valve is opened to cut off the power input from the travel pump to the gearbox; Control the transmission to switch to the target gear; After the gear shifting operation is completed, the bypass valve is closed.

2. The method according to claim 1, characterized in that, Determining the target gear based on the handle gear position signal includes: Get the gear mode of the manual / automatic mode switch; Based on the handle gear position signal, determine the currently allowed highest gear; If the current gear mode is automatic, obtain the current vehicle speed; Using the currently allowed highest gear as a constraint, the target gear is determined by comparing the current vehicle speed with the preset upshift speed threshold and downshift speed threshold corresponding to each gear.

3. The method according to claim 2, characterized in that, The step of determining the target gear based on a comparison between the current vehicle speed and preset upshift and downshift speed thresholds for each gear includes: When the current vehicle speed exceeds the upshift speed threshold corresponding to the first gear, the second gear is determined as the target gear, wherein the second gear is the adjacent higher gear of the first gear, or... When the current vehicle speed is less than the downshift speed threshold corresponding to the second gear, the first gear is set as the target gear, or... When the current vehicle speed is greater than the downshift speed threshold corresponding to the second gear and less than the upshift speed threshold corresponding to the first gear, the current gear is determined as the target gear.

4. The method according to claim 2, characterized in that, The method further includes: If the current gear mode is manual mode, the highest allowed gear is determined as the target gear; If the current gearbox gear is greater than the target gear and the current vehicle speed is higher than the feedforward protection preset value, the current gearbox gear will be determined as the target gear.

5. The method according to claim 1, characterized in that, Controlling the transmission to switch to the target gear, and controlling the bypass valve to close after the gear shift operation is completed, includes: Calculate the pressure difference between the oil ports on both sides of the traveling pump; When the pressure difference is less than a preset difference threshold, the solenoid valve corresponding to the current gear on the transmission is deactivated, and a timer is started. When the first timing duration reaches the first preset duration threshold, the solenoid valve corresponding to the target gear is enabled. After the gear shifting operation is completed, the bypass valve is closed based on the preset bypass valve shut-off curve.

6. The method according to claim 1, characterized in that, The method further includes: When the engine's target speed is set to the preset upshift or downshift speed value, timing begins, and the on / off status of the bypass valve is monitored in real time. When the second timing duration reaches the second preset duration threshold and the bypass valve is in the open state, the shift failure is determined and the current gear of the transmission is maintained.

7. The method according to claim 1, characterized in that, After the vehicle gear shifting operation is completed, the method further includes: Obtain the throttle opening signal; Based on the throttle opening signal, calculate the engine's second target speed; Based on the difference between the second target speed and the current engine speed, a pulse control signal of corresponding frequency is generated to adjust the engine speed; Obtain the gear position signal from the gear lever and the current vehicle speed; Based on the adjusted current engine speed, determine the first target displacement of the travel pump and set the output direction of the travel pump to the gear direction; Based on the current vehicle speed, determine the second target displacement of the travel motor.

8. The method according to claim 7, characterized in that, The method further includes: Obtain the brake pedal opening signal; The third target displacement of the traveling pump is determined based on the opening signal, wherein the opening signal and the third target displacement are inversely proportional. If the first target displacement is not less than the third target displacement, then the first target displacement is updated to the third target displacement; During the process of controlling the operation of the walking pump based on the first target displacement, it is determined whether the absolute value of the first rate of change of the first target displacement exceeds the preset first slope threshold. If the absolute value of the first rate of change of the first target displacement exceeds a preset first slope threshold, the first rate of change of the first target displacement is adjusted to the slope threshold, and... During the process of controlling the operation of the walking motor based on the second target displacement, it is determined whether the absolute value of the second rate of change of the second target displacement exceeds the preset second slope threshold. If the absolute value of the second rate of change of the second target displacement exceeds the preset second slope threshold, the second rate of change of the second target displacement is adjusted to the second slope threshold.

9. The method according to claim 7, characterized in that, The method further includes: Collect the first and second voltage signals output from the accelerator pedal; Divide the first voltage signal by a preset value to obtain the first quotient; Calculate the absolute value of the difference between the first quotient and the second voltage signal, and then apply the absolute value of the difference to the first voltage signal to obtain the throttle synchronization deviation; If the throttle synchronization deviation is not less than the preset deviation threshold, then the throttle opening signal is set to zero.

10. A vehicle, characterized in that, The vehicle includes a vehicle shift control system, which includes a controller, an engine, a travel pump, a travel motor, a bypass valve, and a gearbox. The engine drives the travel pump, the hydraulic oil generated by the travel pump drives the travel motor, and the travel motor transmits power to the gearbox. The bypass valve is connected in the hydraulic output circuit of the travel pump to control the flow path of the hydraulic oil output by the travel pump. The controller includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the vehicle shift control method according to any one of claims 1 to 9.

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