Manual transmission ramp auxiliary control method and system and manual transmission vehicle

Abstract

The invention discloses a manual transmission ramp auxiliary control method and system and a manual transmission vehicle, and relates to the technical field of vehicle control, and the manual transmission ramp auxiliary control method comprises the following steps: detecting whether a vehicle is in a ramp temporary parking state or not; if yes, activating a ramp assist mode, and enabling a braking system to brake the vehicle; calculating a first starting torque required for starting the vehicle according to the ramp angle and the vehicle load, and when an accelerator pedal is stepped and the wheel end driving torque is greater than the first starting torque required for starting the vehicle, releasing the braking of the vehicle by a braking system, and detecting whether the vehicle slides on a slope or not; if yes, the braking system is made to brake the vehicle again; if not, starting of the vehicle is completed, and the ramp assisting mode is quitted. According to the method, the braking system brakes the vehicle on the ramp through the ramp auxiliary mode, and after it is recognized that the ramp starting condition is met, the braking system relieves braking of the vehicle so as to prevent the vehicle with the manual transmission from sliding on the ramp during ramp starting.

Description

Technical Field

[0001] This invention relates to the field of automotive control technology, specifically to a method, system, and manual transmission hill-start assist control for a manual transmission vehicle. Background Technology

[0002] Currently, for electric vehicles starting on a slope, the market can determine whether the electric vehicle is rolling backwards based on gear information and motor speed information. When the electric vehicle is rolling backwards, the motor torque can be increased to brake the car on the slope.

[0003] However, since manual transmissions do not have gear or torque signals before starting on an incline, it is impossible to determine the driver's intention, so the above method is not applicable to solving the problem of manual transmission vehicles rolling backward when starting on an incline. Summary of the Invention

[0004] This invention provides a method, system, and manual transmission vehicle for hill start assist control, which can solve the problem of manual transmission vehicles rolling backward when starting on a slope.

[0005] In a first aspect, embodiments of the present invention provide a manual transmission hill-start assist control method, comprising the following steps: Check if the vehicle is temporarily parked on a slope; If so, activate the hill start assist mode to brake the vehicle using the braking system; The first starting torque required for the vehicle to start is calculated based on the slope angle and vehicle load. When the accelerator pedal is pressed and the wheel-end drive torque is greater than the first starting torque required for the vehicle to start, the braking system is released to check whether the vehicle rolls off the slope. If so, apply the braking system to brake the vehicle again; If not, the vehicle will start and exit hill start assist mode.

[0006] In conjunction with the first aspect, in one embodiment, if so, after the braking system is braked on the vehicle again, the following steps are further included: The second starting torque required for vehicle start-up is calculated based on the slope angle and vehicle load. When the accelerator pedal is pressed and the wheel-end drive torque is greater than the second starting torque required for vehicle start-up, the braking system is released to brake the vehicle, and the vehicle is checked for slippage. If so, apply the brakes to the vehicle again, activate EPB parking brake, and then exit hill start assist mode. If not, the vehicle will start and exit hill start assist mode.

[0007] In conjunction with the first aspect, in one implementation, the step of exiting the hill-start assist mode after activating the EPB parking brake further includes: The dashboard displays a message indicating that hill start assist mode is unavailable and prompts the user to manually initiate a hill start.

[0008] In conjunction with the first aspect, in one implementation, detecting whether the vehicle is in a temporary parking state on a slope includes the following steps: Acquire slope signal, brake pedal position signal, vehicle speed signal and electronic parking status signal; The vehicle is determined to be in a temporary parking state on a slope by using the slope signal, brake pedal position signal, vehicle speed signal, and electronic parking status signal.

[0009] In conjunction with the first aspect, in one embodiment, acquiring the vehicle speed signal includes: Vehicle speed signals are obtained through an onboard GPS module or vehicle speed sensor.

[0010] In conjunction with the first aspect, in one embodiment, braking the vehicle by the braking system includes the following steps: Calculate the hydraulic pressure required to maintain braking based on the slope angle and vehicle load; The braking system maintains the brake circuit pressure at this oil pressure to brake the vehicle.

[0011] In conjunction with the first aspect, in one embodiment, calculating the hydraulic pressure required to maintain braking based on the slope angle and vehicle load includes the following steps: The ramp angle is obtained using an inertial sensor.

[0012] In conjunction with the first aspect, in one embodiment, the step of calculating the hydraulic pressure required to maintain braking based on the slope angle information and vehicle load information further includes the following steps: The hydraulic pressure required to maintain braking can be calculated using the following formula: ; in, Indicates the vehicle's full load weight. Indicates the slope angle. This represents the braking force generated by a unit of hydraulic pressure in a single front brake. This indicates the braking force generated by a single unit of hydraulic pressure in a rear brake.

[0013] Secondly, embodiments of the present invention provide a manual transmission hill start assist control system, which is used to implement the aforementioned manual transmission hill start assist control method.

[0014] Thirdly, embodiments of the present invention provide a manual transmission vehicle, including: a manual transmission hill-start assist control system.

[0015] This invention discloses a method, system, and manual transmission hill start assist control for a manual transmission vehicle. The method includes the following steps: detecting whether the vehicle is in a temporary parking state on a slope; if so, activating the hill start assist function to brake the vehicle; calculating the first starting torque required for vehicle start-up based on the slope angle and vehicle load; when the accelerator pedal is depressed and the wheel-end drive torque is greater than the first starting torque required for vehicle start-up, releasing the brakes and detecting whether the vehicle rolls back; if so, re-braking the vehicle; if not, the vehicle completes the start and exits the hill start assist mode. This invention uses the hill start assist mode to brake the vehicle on a slope and releases the brakes after recognizing that the conditions for starting on a slope are met to prevent manual transmission vehicles from rolling back when starting on a slope. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a first flowchart of a manual transmission hill-start assist control method according to an embodiment of the present invention; Figure 2 This is a second flowchart of a manual transmission ramp assist control method according to an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0019] Currently, commercially available solutions for starting electric vehicles on inclines can determine if the vehicle is rolling backward based on gear position and motor speed information. If so, the motor torque can be increased to brake the vehicle on the incline. However, since manual transmissions do not provide gear position and torque signals before starting on an incline, it is impossible to determine the driver's intention, making the above methods unsuitable for addressing the rolling backward issue when starting a manual transmission vehicle on an incline.

[0020] like Figure 1As shown, this invention discloses a manual transmission hill start assist control method, characterized by the following steps: detecting whether the vehicle is in a temporary hill stop state; if so, activating the hill start assist mode and braking the vehicle with the braking system; calculating the first starting torque required for the vehicle to start based on the hill angle and vehicle load; when the accelerator pedal is pressed and the wheel-end drive torque is greater than the first starting torque required for the vehicle to start, releasing the braking system from the vehicle and detecting whether the vehicle rolls back down the hill; if so, braking the vehicle again with the braking system; if not, the vehicle completes the start and exits the hill start assist mode.

[0021] When the system detects that the vehicle is on a slope, the driver has applied the brake pedal, the vehicle speed is 0, and the electronic parking brake is not activated, the system will determine that the car is in a temporary parking state on a slope. Based on this information, the system will activate the hill start assist mode. At this time, the hill start assist mode will calculate the required hydraulic pressure for parking based on the slope size and the vehicle's full load weight, and control the braking system to maintain the brake circuit pressure at that pressure to brake the vehicle and bring it to a standstill.

[0022] Because the hill start assist mode controls the braking system to maintain brake circuit pressure at this hydraulic pressure to brake the vehicle, releasing the brake pedal will maintain brake circuit pressure to keep the vehicle stationary on the slope and prevent it from rolling back. At this time, the system will calculate the force required for the vehicle to start based on the slope angle and vehicle load, and calculate the theoretical starting torque required for starting according to the first gear ratio.

[0023] When starting is required, the driver releases the brake pedal and presses the accelerator. Because the hill start assist mode controls the braking system to maintain brake circuit pressure at this pressure, the vehicle will not roll backward when the driver releases the brake pedal and presses the accelerator. The system estimates the clutch engagement depth based on engine speed and output torque. Once the clutch is fully engaged, it calculates the wheel-end drive torque. As the accelerator pedal travels, the wheel-end drive torque gradually increases. When the wheel-end drive torque exceeds the theoretical starting torque required based on the first gear ratio, the hill start assist mode releases the brakes and checks if the vehicle rolls backward after the brakes are released. If it rolls backward, the start was unsuccessful, and the hill start assist mode will re-engage the braking system to bring the vehicle to a stop. If it does not roll backward, the start was successful, the vehicle starts normally, and the system exits the hill start assist mode.

[0024] Adding a feature to detect whether the vehicle is rolling backwards after the braking system is released can prevent the vehicle from rolling backwards due to insufficient starting torque caused by overloading during the start-up process. If rolling backwards does occur, the hill start assist mode will re-engage the braking system to brake the vehicle and stop it in time, increasing vehicle safety when starting on an incline.

[0025] This invention enables the braking system to brake the vehicle on a slope using a hill start assist mode, and releases the brakes after recognizing that the conditions for starting on a slope are met, to prevent manual transmission vehicles from rolling backward when starting on a slope.

[0026] like Figure 2 As shown, in one embodiment, if the condition is met, after the braking system brakes the vehicle again, the following steps are further included: calculating the second starting torque required for the vehicle to start based on the slope angle and vehicle load; when the accelerator pedal is pressed and the wheel-end drive torque is greater than the second starting torque required for the vehicle to start, the braking system releases the vehicle, and checks whether the vehicle rolls off the slope; if met, the braking system brakes the vehicle again, and the EPB parking brake is activated before exiting the hill start assist mode; if not, the vehicle completes the start and exits the hill start assist mode.

[0027] If the initial starting torque is calculated based on the first gear ratio and the initial start fails, and the braking system is applied to the vehicle again, the system will calculate the force required for the vehicle to start based on the slope angle and vehicle load, and then calculate the second starting torque based on the second gear ratio.

[0028] When starting is required, the driver releases the brake pedal and presses the accelerator. Because the hill start assist mode controls the braking system to maintain brake circuit pressure to brake the vehicle, the vehicle will not roll backwards from the moment the driver releases the brake pedal to the moment they press the accelerator. The system estimates the clutch engagement depth based on engine speed and output torque. Once the clutch is fully engaged, it calculates the wheel-end drive torque. During accelerator pedal operation, the wheel-end drive torque gradually increases with the accelerator pedal travel. When the wheel-end drive torque exceeds the theoretical starting torque required based on the 2nd gear transmission ratio, the hill start assist mode releases the brakes and checks if the vehicle rolls backwards after the brakes are released. If it does, the start was unsuccessful, and the hill start assist mode will re-engage the brakes, activate the EPB parking brake, and then exit the hill start assist mode, bringing the vehicle to a stop. If no roll occurs, the start was successful, the vehicle starts normally, and the system exits the hill start assist mode.

[0029] If the hill start assist mode fails to calculate the required first and second starting torques according to the gear ratios of 1st and 2nd gear in sequence, it means that the vehicle is stopped on a steep slope or the vehicle is heavily loaded, and the conditions for hill start through hill start assist mode are not met. At this time, the system exits hill start assist mode, activates EPB parking, and prompts the driver to manually start on the hill through the display screen.

[0030] Adding a feature to detect whether the vehicle is rolling backwards after the braking system is released can prevent the vehicle from rolling backwards due to insufficient starting torque caused by overloading or excessively steep inclines. If rolling backwards does occur, the hill start assist mode will re-engage the braking system to brake the vehicle and stop it in time, increasing vehicle safety when starting on an incline.

[0031] This invention adjusts the drive torque provided by the wheel end by setting two ramp start judgments to adapt to a wider range of slopes.

[0032] like Figure 2 As shown, in one embodiment, the step of exiting the hill start assist mode after activating EPB parking also includes: displaying a message on the instrument panel indicating that the hill start assist mode is unavailable and prompting the user to manually perform a hill start.

[0033] When the slope is too steep, in order to further remind the driver that the hill start assist mode is unavailable, in addition to activating EPB parking, the system also prompts the driver through the instrument panel that the hill start assist mode is unavailable and prompts the driver to manually start on the hill, so as to clearly provide the driver with the information that manual hill start is required.

[0034] This invention further increases the ways in which information requiring manual hill start is provided to the driver by setting a dashboard prompt that hill start assist mode is unavailable and prompting the driver to manually perform hill start. This makes the information provided to the driver more accurate and timely.

[0035] like Figure 1 , 2 As shown, in one embodiment, detecting whether the vehicle is in a temporary parking state on a slope includes the following steps: acquiring slope signal, brake pedal position signal, vehicle speed signal and electronic parking status signal; determining whether the vehicle is in a temporary parking state on a slope based on the slope signal, brake pedal position signal, vehicle speed signal and electronic parking status signal.

[0036] The vehicle being in a temporary parking state on a slope is a prerequisite for activating the hill start assist mode. This invention activates the hill start assist mode by determining whether the vehicle is in a temporary parking state on a slope. The specific determination process is as follows: the system acquires the slope signal, brake pedal position signal, vehicle speed signal, and electronic parking status signal. The system determines that the vehicle is in a temporary parking state on a slope when all four conditions are met simultaneously: the vehicle is in a slope position signal, the brake pedal is depressed and has a position signal, the vehicle speed has dropped to 0, and the electronic parking status is not engaged.

[0037] If a slope signal is received, it indicates that the vehicle is on a slope, which meets the basic conditions for activating the slope assist mode.

[0038] If a position signal is received indicating that the brake pedal has been pressed, it means that the driver has taken action to brake.

[0039] If the vehicle speed drops to 0, it indicates that the vehicle is currently stationary.

[0040] If the electronic parking brake is not engaged, it indicates that the vehicle is in a temporary parking state.

[0041] When all four pieces of information are obtained simultaneously, the system can clearly determine that the vehicle is in a temporary parking state on a slope, at which point the slope assist mode is activated.

[0042] This invention improves the accuracy of determining whether a vehicle is in a temporary parking state on a slope by setting four judgment conditions. The slope assist mode will only be activated when all four conditions are met simultaneously.

[0043] In one embodiment, acquiring the vehicle speed signal includes: acquiring the vehicle speed signal through an onboard GPS module or a vehicle speed sensor.

[0044] In order to accurately obtain vehicle speed and improve the accuracy of determining whether a vehicle is temporarily parked on a slope, this invention can obtain vehicle speed signals through an onboard GPS module or a vehicle speed sensor.

[0045] The vehicle GPS module determines the vehicle speed by receiving satellite signals to calculate the travel distance and time. The error can be controlled within 0.5 km / h. It can also update the location data in real time and calculate the current speed to ensure the accuracy of the information obtained.

[0046] The vehicle speed sensor can be a Hall effect sensor. A Hall effect sensor senses the periodic changes in magnetic field strength caused by the rotation of a permanent magnet within the wheel as it rotates along the shaft. This periodic magnetic field strength change is then converted into a periodic voltage signal. This voltage signal is amplified and processed to form a pulse output. The ECU calculates the vehicle speed based on the pulse frequency and wheel parameters. Hall effect speed sensors offer advantages such as high accuracy, fast response, and strong anti-interference capabilities.

[0047] This invention increases the accuracy of vehicle speed measurement by using an onboard GPS module or vehicle speed sensor, thereby increasing the accuracy of determining whether a vehicle is temporarily parked on a slope.

[0048] In one embodiment, braking the vehicle by the braking system includes the following steps: calculating the hydraulic pressure required to maintain braking based on the slope angle and vehicle load; and braking the vehicle by maintaining the braking circuit pressure at the hydraulic pressure.

[0049] When the hill start assist mode is activated, the system calculates the component of the vehicle's weight along the slope direction based on the vehicle's full load weight and the slope angle. The system then calculates the braking force that the braking system needs to provide based on the component of the vehicle's weight along the slope direction. Based on the braking force, the system calculates the oil pressure required for braking and controls the braking system to maintain the braking circuit pressure according to the oil pressure, so that the vehicle remains stationary on the slope.

[0050] This invention accurately calculates the required oil pressure for braking by using information on slope and vehicle load weight, so that the braking system can provide braking force at the oil pressure that just meets the braking requirements.

[0051] In one embodiment, calculating the hydraulic pressure required to maintain braking based on the ramp angle and vehicle load includes the following steps: obtaining the ramp angle using an inertial sensor.

[0052] The inertial sensor operates on the principle of Newton's first law and the law of conservation of angular momentum, calculating angle changes by detecting changes in angular velocity and acceleration. Furthermore, the inertial sensor includes a gyroscope and an accelerometer. The gyroscope, based on microelectromechanical systems (MEMS) technology, measures angular velocity by detecting vibrations or changes in current in a mass; the accelerometer, also based on MEMS technology, detects the acceleration components of the carrier in three directions within the coordinate system. During measurement, by integrating the angular velocity data and combining it with initial attitude information, the carrier's attitude angle in three-dimensional space is calculated in real time; this attitude angle represents the slope information.

[0053] This invention can accurately obtain the slope angle through an inertial sensor, which provides a basis for judging whether the vehicle is in a temporary parking state on a slope; on the other hand, the accurate angle can be used to calculate the oil pressure required for the braking system to provide braking force.

[0054] In one embodiment, calculating the hydraulic pressure required to maintain braking based on the slope angle information and vehicle load information further includes the following steps: The hydraulic pressure required to maintain braking can be calculated using the following formula: ; in, Indicates the vehicle's full load weight. Indicates the slope angle. This represents the braking force generated by a unit of hydraulic pressure in a single front brake. This indicates the braking force generated by a single unit of hydraulic pressure in a rear brake.

[0055] The braking force produced by the unit hydraulic pressure refers to the braking force generated by 1 MPa hydraulic pressure.

[0056] This invention, by combining the obtained vehicle load mass and slope angle with the braking parameters of the vehicle braking system, can accurately convert the required braking force into the oil pressure required to maintain braking, so as to facilitate the control of the braking system to maintain the braking circuit pressure according to the oil pressure, and keep the vehicle stationary on the slope.

[0057] The present invention also discloses a manual transmission hill start assist control system, which is used to implement the manual transmission hill start assist control method described in the claims.

[0058] This invention provides a hill-start assist control method for manual transmissions, making it easier for drivers to start manual transmission vehicles on inclines. Furthermore, by incorporating a step to detect whether the vehicle is rolling backward after starting, the safety of manual transmission vehicles during hill starts can be effectively increased.

[0059] The present invention also discloses a manual transmission vehicle, which includes: the aforementioned manual transmission hill-start assist control system.

[0060] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0061] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0062] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for hill-start assist control of a manual transmission, characterized in that, Includes the following steps: Check if the vehicle is temporarily parked on a slope; If so, activate the hill start assist mode to brake the vehicle using the braking system; The first starting torque required for the vehicle to start is calculated based on the slope angle and vehicle load. When the accelerator pedal is pressed and the wheel-end drive torque is greater than the first starting torque required for the vehicle to start, the braking system is released to check whether the vehicle rolls off the slope. If so, apply the braking system to brake the vehicle again; If not, the vehicle will start and exit hill start assist mode.

2. The manual transmission hill-start assist control method according to claim 1, characterized in that, If so, after braking the vehicle again, the following steps are also included: The second starting torque required for vehicle start-up is calculated based on the slope angle and vehicle load. When the accelerator pedal is pressed and the wheel-end drive torque is greater than the second starting torque required for vehicle start-up, the braking system is released to brake the vehicle, and the vehicle is checked for slippage. If so, apply the brakes to the vehicle again, activate EPB parking brake, and then exit hill start assist mode. If not, the vehicle will start and exit hill start assist mode.

3. The manual transmission hill-start assist control method according to claim 2, characterized in that, The process of activating EPB parking brake and then exiting hill start assist mode also includes: The dashboard displays a message indicating that hill start assist mode is unavailable and prompts the user to manually initiate a hill start.

4. The manual transmission hill-start assist control method according to claim 1, characterized in that, The process of detecting whether a vehicle is temporarily parked on a slope includes the following steps: Acquire slope signal, brake pedal position signal, vehicle speed signal and electronic parking status signal; The vehicle is determined to be in a temporary parking state on a slope by using the slope signal, brake pedal position signal, vehicle speed signal, and electronic parking status signal.

5. The manual transmission hill-start assist control method according to claim 4, characterized in that, The acquisition of the vehicle speed signal includes: Vehicle speed signals are obtained through an onboard GPS module or vehicle speed sensor.

6. The manual transmission hill-start assist control method according to claim 1, characterized in that, The method of braking the vehicle using the braking system includes the following steps: Calculate the hydraulic pressure required to maintain braking based on the slope angle and vehicle load; The braking system maintains the brake circuit pressure at this oil pressure to brake the vehicle.

7. A manual transmission hill-start assist control method according to claim 6, characterized in that, The calculation of the hydraulic pressure required to maintain braking based on the slope angle and vehicle load includes the following steps: The ramp angle is obtained using an inertial sensor.

8. A manual transmission hill-start assist control method according to claim 6, characterized in that, The calculation of the hydraulic pressure required to maintain braking based on the slope angle information and vehicle load information also includes the following steps: The hydraulic pressure required to maintain braking can be calculated using the following formula: ; in, Indicates the vehicle's full load weight. Indicates the slope angle. This represents the braking force generated by a unit of hydraulic pressure in a single front brake. This indicates the braking force generated by a single unit of hydraulic pressure in a rear brake.

9. A manual transmission hill-start assist control system, characterized in that: The system is used to implement the manual transmission ramp assist control method according to any one of claims 1 to 8.

10. A manual transmission vehicle, characterized in that, include: The manual transmission hill start assist control system as described in claim 9.

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