A vehicle starting control method and vehicle based on a dual clutch transmission

Abstract

The application provides a vehicle starting control method based on a double clutch gearbox, when the vehicle starts, whether the current state of the vehicle meets the preset compensation activation condition is judged according to the state parameters of the vehicle, and when the current state of the vehicle meets the preset compensation activation condition, the real-time output torque of the engine is temporarily increased from the preset first output torque limit to the preset second output torque limit, the output torque limit value of the engine is increased, the final torque output of the double clutch is increased, and the thrust of the steep slope starting is increased, and the reliability of the starting is increased; after the vehicle completes the starting, the torque limit is restored, the damage risk of the high torque to the mechanical transmission structure is avoided, and the safety is ensured. Through the temporary release of the engine output torque limit for a short time, the reliability of the steep slope starting of the vehicle can be effectively improved under the condition of ensuring the safety, and the driving experience of the user is improved.

Description

Technical Field

[0001] This invention relates to the field of automobile start-up control technology, and in particular to a vehicle start-up control method and vehicle based on a dual-clutch transmission. Background Technology

[0002] Starting on a steep slope is one of the most common operating conditions for cars on slopes. Typical scenarios include starting on a slope at the exit of an underground parking garage, on unpaved roads in mountainous areas, on highway ramps, and on off-road sections.

[0003] For example, the slope of a steep underground parking garage is typically 15% to 20%, while the maximum gradeability of a regular family car is about 30%, which is sufficient for daily use. However, in some underground parking garages and extreme off-road steep slope scenarios, the slope may exceed the design standard of 30%, making it easy to fail to start when going uphill, thus affecting the user's driving experience. Summary of the Invention

[0004] Therefore, the purpose of this invention is to provide a vehicle start-up control method based on a dual-clutch transmission to solve the problem that vehicles in the prior art are prone to start-up failure when starting on steep slopes that exceed design standards.

[0005] This invention provides a vehicle start-up control method based on a dual-clutch transmission, comprising: Collect the vehicle's status parameters and determine whether the vehicle's current status meets the preset compensation activation conditions based on the status parameters. When the current state of the vehicle meets the preset compensation activation conditions, the real-time output torque limit of the engine is increased from the preset first output torque limit to the preset second output torque limit. When the vehicle exits the compensation activation condition in its current state, the real-time output torque limit of the engine is switched back from the second output torque limit to the first output torque limit, thus completing the vehicle start-up control.

[0006] Optionally, the compensation activation condition includes: The current gear is the preset low-speed starting gear; The current vehicle speed is less than the preset vehicle speed threshold; The slope is greater than or equal to the preset slope threshold; Even-numbered gear clutch torque is greater than or equal to the preset clutch torque threshold. Specifically, if all the compensation activation conditions are met, the current state of the vehicle is determined to meet the compensation activation conditions; otherwise, the current state of the vehicle is determined to be out of the compensation activation conditions.

[0007] Optionally, the second output torque is limited to the maximum value of the engine's preset torque limit.

[0008] Optionally, the first output torque limit is the torque limit of the first gear of the transmission.

[0009] Optionally, the step of raising the real-time output torque limit of the engine from a preset first output torque limit to a preset second output torque limit includes: The engine's real-time output torque limit is gradually released according to the preset torque growth rate until the engine's real-time output torque limit changes from the first output torque limit to the second output torque limit.

[0010] Optionally, the step of raising the real-time output torque limit of the engine from a preset first output torque limit to a preset second output torque limit further includes: obtaining a compensation value based on the torque growth rate, and using the sum of the first output torque limit and the compensation value as the real-time output torque limit of the engine; The step of reducing the real-time output torque limit of the engine from the second output torque limit back to the first output torque limit includes: gradually reducing the compensation value of the torque increase rate until the compensation value returns to zero.

[0011] In another aspect, the present invention provides a vehicle that uses the above-described vehicle start-up control method based on a dual-clutch transmission to control the vehicle's start-up.

[0012] The vehicle start-up control method based on a dual-clutch transmission provided by this invention determines whether the vehicle's current state meets preset compensation activation conditions based on the vehicle's state parameters during vehicle start-up. If the current state meets these conditions, the real-time output torque limit of the engine is temporarily increased from a preset first output torque limit to a preset second output torque limit. This increases the engine's output torque limit value, thereby increasing the final torque output of the dual-clutch transmission and improving the thrust for steep hill starts, thus enhancing start-up reliability. After the vehicle completes start-up, the torque limit is restored to avoid the risk of damage to the mechanical transmission structure from high torque, ensuring safety. This invention, by temporarily releasing the engine output torque limit for a short period, effectively improves the reliability of steep hill starts while ensuring safety, enhancing the user's driving experience. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the architecture of a dual-clutch transmission in the prior art; Figure 2 The test results of vehicle state parameters when a steep uphill start fails in the existing technology; Figure 3 The results are based on tests of throttle opening and vehicle speed when starting on a steep slope fails, as described in existing technologies. Figure 4This is a flowchart of the vehicle start-up control method based on a dual-clutch transmission in an embodiment of the present invention. Figure 5 This is a test diagram of vehicle state parameters during the implementation of the vehicle start-up control method based on a dual-clutch transmission in an embodiment of the present invention. Figure 6 These are the test results of throttle opening and vehicle speed during a steep uphill start in this embodiment of the invention.

[0014] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0015] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0016] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0018] For dual-clutch transmissions, when starting, both the odd-numbered and even-numbered clutches are engaged simultaneously, such as... Figure 1 As shown, the engine torque of the dual-clutch transmission is transmitted to the first input shaft 11 and the second input shaft 12 via the odd-numbered clutch and the even-numbered clutch, respectively. The torque of the first input shaft 11 and the second input shaft 12 is then transmitted to the output shaft 21 via a set of gears. The torque of the output shaft 21 is then transmitted to the wheel axle 31, outputting the torque to the wheels. When both clutches are engaged, the engine torque can be distributed across the two clutches, outputting through two torque transmission paths. This reduces the torque burden on a single torque transmission path, lowers the risk of damage due to excessive torque transmission in a single path, and improves reliability.

[0019] To ensure the reliability of the mechanical transmission structure and reduce the risks of shaft breakage and gear damage, existing technologies limit the maximum output torque of the first-gear engine to avoid excessive torque.

[0020] In a specific example, when starting in first gear on a 40% incline, the throttle opening was directly increased to 100%, and the test results were as follows: Figure 2 and Figure 3 As shown, in the existing technology, the engine torque limit is 220 N·m. When the real-time engine torque reaches 220 N·m, it cannot be increased further. The sum of the torques of the odd-numbered clutch and the even-numbered clutch is limited, and the torque transmitted to the wheel axle is insufficient, resulting in a failed start and a zero vehicle speed.

[0021] To address the issue of vehicle start-up failure when starting on steep inclines exceeding design standards, this invention provides a vehicle start-up control method based on a dual-clutch transmission. During vehicle start-up, the method determines whether the vehicle's current state meets preset compensation activation conditions based on its state parameters. If the conditions are met, the real-time output torque limit of the engine is temporarily increased from a first preset limit to a second preset limit. This increases the engine's output torque limit, thereby increasing the maximum clutch engagement force, enhancing the clutch's torque transmission capability, and reducing the risk of clutch slippage and overheating, which could trigger overheat protection and cause engine stalling. This improves the reliability of steep incline starts. After the vehicle completes start-up, its current state exits the compensation activation conditions, and the engine's real-time output torque limit reverts from the second limit back to the first limit, restoring the original torque limit. This avoids the risk of gear damage due to prolonged exposure to high torque, ensuring safety. This invention effectively improves the reliability of steep incline starts while ensuring safety, enhancing the user's driving experience.

[0022] Specifically, such as Figure 4 As shown, the vehicle start-up control method based on a dual-clutch transmission in this embodiment includes: Step S01: Collect the vehicle's status parameters and determine whether the vehicle's current status meets the preset compensation activation conditions based on the status parameters. Step S02: When the current state of the vehicle meets the preset compensation activation conditions, the real-time output torque limit of the engine is increased from the preset first output torque limit to the preset second output torque limit; Step S03: When the vehicle exits the compensation activation condition in its current state, the real-time output torque limit of the engine is switched from the second output torque limit back to the first output torque limit to complete the vehicle start control.

[0023] By temporarily lifting the engine's real-time output torque limit, the torque output capability can be increased, thereby improving the final output torque and the reliability of hill starts. After a successful start, the engine's real-time output torque limit should be restored in a timely manner to ensure safety.

[0024] Specifically, the compensation activation conditions include: the current gear is a preset low-speed starting gear (usually first gear, and for vehicles equipped with dual clutches that simultaneously drive dual reverse gear sets, reverse gear is also included), the current vehicle speed is less than a preset vehicle speed threshold, the slope is greater than or equal to a preset slope threshold, and the torque of the even-numbered gear clutch is greater than or equal to a preset clutch torque threshold.

[0025] If all compensation activation conditions are met, the current state of the vehicle is determined to meet the compensation activation conditions; otherwise, the current state of the vehicle is determined to exit the compensation activation conditions.

[0026] To ensure that the final output torque can effectively drive the vehicle to start, in this embodiment, the second output torque limit is the maximum value of the engine's preset torque limit. For example, the engine preset torque limit has three levels: 220 N·m, 260 N·m, and 300 N·m, which are the engine torque limits in first gear, second gear, and third gear, respectively. Then, the value of the second output torque limit is 300 N·m, which can be determined according to the specific configuration of the vehicle.

[0027] To ensure safety at low speeds, in this embodiment, the first output torque limit is the torque limit of the first gear in the transmission. The difference between the torque limit of the first gear and its torque tolerance limit is significant; generally, the torque tolerance limit of the first gear is 1.5 times the torque limit, providing ample operational flexibility. Even if the torque limit is temporarily exceeded for a short period, the final torque will still differ from the torque tolerance limit, ensuring safety.

[0028] To avoid sudden torque changes when the torque limit is lifted, in this embodiment, step S02 further includes: gradually lifting the real-time output torque limit of the engine according to a preset torque growth rate until the real-time output torque limit of the engine reaches the second output torque limit from the first output torque limit.

[0029] Furthermore, for ease of calculation, in this embodiment, step S02 further includes: obtaining a compensation value based on the torque growth rate, and using the sum of the first output torque limit and the compensation value as the real-time output torque limit of the engine; step S03 further includes: gradually reducing the compensation value based on the torque growth rate until the compensation value returns to zero.

[0030] The compensation value can be obtained through an independent constant current integrator circuit, and then superimposed on the original engine torque limit value through an adder to obtain the final engine torque limit value, or it can be implemented through the software logic of the original controller of the transmission. The specific choice can be made according to actual needs.

[0031] In a specific example, the compensation activation conditions include: the current gear is first gear, the current vehicle speed is less than 10 km / h, the gradient is greater than or equal to 30%, the clutch torque of even-numbered gears is greater than or equal to 100 N·m, and the gradient is 40%. The test results are as follows: Figure 5 and Figure 6 As shown, when all compensation activation conditions are met, the engine torque limit gradually increases from 220 N·m to 300 N·m. During the start-up process, the real-time engine torque reaches 260 N·m, and the peak torque of the even-numbered gear clutch exceeds 200 N·m. The vehicle speed steadily increases, enabling a start. After the start-up is completed, the vehicle speed increases to over 10 km / h, the compensation activation conditions are exited, and the engine torque limit gradually returns from 300 N·m to 220 N·m. After the vehicle starts, as the speed further increases, the engine torque limit generally decreases gradually, slowly increasing to other limit values, such as 260 N·m in second gear or 300 N·m in third gear.

[0032] Among them, according to Figure 2 and Figure 5 In contrast, in existing technologies, the maximum torque of the even-numbered gear clutch is less than 180 N·m when starting on a steep incline, leading to starting failure. However, the even-numbered gear clutch in this application has a maximum torque exceeding 200 N·m, effectively increasing the final output torque and ensuring reliable starting on steep inclines. It eliminates the need to exit the incline, accelerate, and then climb again, significantly improving the user's driving experience.

[0033] This invention also provides a vehicle that uses the aforementioned vehicle start-up control method based on a dual-clutch transmission to control vehicle start-up. The parameters required for the compensation activation condition, including the current gear, current speed, gradient, and torque parameters of the even-numbered gear clutch, can be obtained from existing control systems such as the vehicle domain controller and the vehicle controller, or collected by independent sensors. In other words, the data acquisition method is a conventional approach in the field, and this application does not impose any particular limitation on it, nor does it restrict the feasibility of this application.

[0034] The vehicle start-up control method based on a dual-clutch transmission provided by this invention determines whether the vehicle's current state meets preset compensation activation conditions based on the vehicle's state parameters during vehicle start-up. If the current state meets the preset compensation activation conditions, the real-time output torque limit of the engine is temporarily increased from a preset first output torque limit to a preset second output torque limit. This increases the engine's output torque limit value, thereby increasing the final torque output of the dual-clutch transmission and thus improving the thrust for steep hill starts and enhancing start-up reliability. After the vehicle completes start-up, the torque limit is restored to avoid the risk of damage to the mechanical transmission structure from high torque, ensuring safety. By temporarily releasing the engine output torque limit for a short period, the reliability of steep hill starts can be effectively improved while ensuring safety, enhancing the user's driving experience.

[0035] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0036] The above-described embodiments are merely illustrative of several specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A vehicle start-up control method based on a dual-clutch transmission, characterized in that, include: Collect the vehicle's status parameters and determine whether the vehicle's current status meets the preset compensation activation conditions based on the status parameters. When the current state of the vehicle meets the preset compensation activation conditions, the real-time output torque limit of the engine is increased from the preset first output torque limit to the preset second output torque limit. When the vehicle exits the compensation activation condition in its current state, the real-time output torque limit of the engine is switched back from the second output torque limit to the first output torque limit, thus completing the vehicle start-up control.

2. The vehicle start-up control method based on a dual-clutch transmission according to claim 1, characterized in that, The compensation activation conditions include: The current gear is the preset low-speed starting gear; The current vehicle speed is less than the preset vehicle speed threshold; The slope is greater than or equal to the preset slope threshold; Even-numbered gear clutch torque is greater than or equal to the preset clutch torque threshold. Specifically, if all the compensation activation conditions are met, the current state of the vehicle is determined to meet the compensation activation conditions; otherwise, the current state of the vehicle is determined to be out of the compensation activation conditions.

3. The vehicle start-up control method based on a dual-clutch transmission according to claim 2, characterized in that, The second output torque limit is the maximum value of the engine's preset torque limit.

4. The vehicle start-up control method based on a dual-clutch transmission according to claim 3, characterized in that, The first output torque limit is the torque limit of the first gear of the transmission.

5. The vehicle start-up control method based on a dual-clutch transmission according to claim 1, characterized in that, The steps to increase the engine's real-time output torque limit from a preset first output torque limit to a preset second output torque limit include: The engine's real-time output torque limit is gradually released according to the preset torque growth rate until the engine's real-time output torque limit changes from the first output torque limit to the second output torque limit.

6. The vehicle start-up control method based on a dual-clutch transmission according to claim 5, characterized in that, The step of increasing the real-time output torque limit of the engine from a preset first output torque limit to a preset second output torque limit further includes: obtaining a compensation value based on the torque growth rate, and using the sum of the first output torque limit and the compensation value as the real-time output torque limit of the engine; The step of reducing the real-time output torque limit of the engine from the second output torque limit back to the first output torque limit includes: gradually reducing the compensation value of the torque increase rate until the compensation value returns to zero.

7. A vehicle, characterized in that, The vehicle starts using the vehicle start control method based on a dual-clutch transmission as described in any one of claims 1 to 6.

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