A method and system for obtaining the target gear position of a hybrid vehicle

Abstract

The present invention relates to a method and system for obtaining a target gear position for a hybrid electric vehicle. The method comprises: determining whether gear correction is required; if correction is required, determining the target gear position by: obtaining the corresponding upshift position based on an upshift map and the current vehicle speed; obtaining the corresponding downshift position based on a downshift map and the current vehicle speed; comparing the current gear position with the upshift position, setting the larger value as the intermediate gear position; then comparing the intermediate gear position with the downshift position, setting the smaller value as the target gear position; and if correction is not required, determining the target gear position by: obtaining the target gear position based on a preset basic shift map according to the current throttle and vehicle speed. The present invention corrects the motor gear position after the engine is shut down, thereby improving the motor operating efficiency of a P2 hybrid electric vehicle when driving in hybrid mode, thereby improving the overall vehicle economy.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a method for controlling the power field of a P2 configuration hybrid electric vehicle. Background Art

[0002] P2 hybrid vehicles utilize a traditional internal combustion engine and an electric motor as their power sources. They typically offer users a choice of driving modes, including pure electric mode and hybrid mode. In hybrid mode, the vehicle controller distributes torque output between the electric motor and the engine based on the vehicle's operating state, with the engine participating in or shutting down as needed. Equipped with an automatic transmission, the target gear calculation in hybrid mode significantly impacts the vehicle's power efficiency.

[0003] When operating in hybrid mode, current P2 hybrid vehicles generally use the same target gear calculation method used for traditional internal combustion engine vehicles. Specifically, various shift maps are configured based on the vehicle's current state, road conditions, and the driving environment. These maps typically utilize two parameters: throttle and vehicle speed. These shift maps are designed with reference to the engine's universal characteristics. When operating in hybrid mode, the engine of a P2 hybrid vehicle frequently switches between starting and stopping. When the engine is engaged, the engine speed and the electric motor speed are equal. However, the engine's most efficient speed and torque ranges differ from those of the electric motor. Therefore, when the engine is stopped, the electric motor may not necessarily operate in its most efficient range, necessitating a reconfiguration of the target gear to improve its efficiency. Summary of the Invention

[0004] One purpose of the present invention is to provide a method for obtaining a target gear of a hybrid electric vehicle to solve the problem of low motor efficiency after the engine is shut down; the second purpose is to provide a system for obtaining a target gear of a hybrid electric vehicle.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for obtaining a target gear position of a hybrid electric vehicle is characterized by:

[0007] Determine whether gear correction is required;

[0008] If correction is required, the target gear is determined in the following manner:

[0009] Based on the upshift map, the corresponding upshift position is obtained according to the current vehicle speed;

[0010] Based on the downshift map, the corresponding downshift gear is obtained according to the current vehicle speed;

[0011] Compare the current gear with the upshift gear, let the larger value be the middle gear, then compare the middle gear with the downshift gear, let the smaller value be the target gear;

[0012] If no correction is required, the target gear is determined in the following manner:

[0013] The target gear is obtained based on the preset basic shift map according to the current throttle and vehicle speed.

[0014] According to the above technical means, the motor efficiency is related to the motor speed and torque. By changing the target gear, the motor speed can be changed, thereby changing the motor working efficiency.

[0015] Furthermore, when all of the following conditions are met simultaneously and for a set period of time, it is determined that a gear correction is required;

[0016] The current driving mode is hybrid mode;

[0017] The engine speed is less than a first preset speed;

[0018] The vehicle acceleration is less than a first preset acceleration threshold;

[0019] If the brake pedal is in a brake-pressed state, the vehicle acceleration is greater than a second preset acceleration threshold, and the first preset acceleration threshold is greater than the second preset acceleration threshold;

[0020] The accelerator pedal opening is less than a first opening threshold.

[0021] Furthermore, if any of the following conditions are met, it is determined that no gear correction is required;

[0022] The current driving mode is not hybrid;

[0023] The engine speed is greater than a second preset speed, and the second preset speed is greater than the first preset speed;

[0024] The vehicle acceleration is greater than a third preset acceleration threshold;

[0025] The accelerator pedal opening is greater than a second opening threshold, and the second opening threshold is greater than the first opening threshold;

[0026] The first preset acceleration threshold is smaller than the third preset acceleration threshold.

[0027] Furthermore, the method for obtaining the corresponding upshift position according to the current vehicle speed based on the upshift map is as follows:

[0028] According to the vehicle speed coordinate axis of the upshift map, the first vehicle speed value greater than the current vehicle speed is searched in ascending order, and the gear position value corresponding to the vehicle speed value is obtained, and the gear position is the upshift gear position.

[0029] Furthermore, the method for obtaining the corresponding downshift position according to the current vehicle speed based on the downshift map is as follows:

[0030] According to the vehicle speed coordinate axis of the downshift map, the first vehicle speed value that is less than the current vehicle speed is searched in descending order, and the gear position corresponding to the vehicle speed value is obtained, and the gear position is the downshift gear position.

[0031] A hybrid electric vehicle target gear acquisition system, comprising:

[0032] A judgment module configured to judge whether a gear correction is required;

[0033] The first execution module is configured to determine the target gear position in the following manner if correction is required:

[0034] Based on the upshift map, the corresponding upshift position is obtained according to the current vehicle speed;

[0035] Based on the downshift map, the corresponding downshift gear is obtained according to the current vehicle speed;

[0036] Compare the current gear with the upshift gear, let the larger value be the middle gear, then compare the middle gear with the downshift gear, let the smaller value be the target gear;

[0037] The second execution module is configured to determine the target gear position in the following manner if no correction is required:

[0038] The target gear is obtained based on the preset basic shift map according to the current throttle and vehicle speed.

[0039] Furthermore, when all of the following conditions are met simultaneously and continue for a set time, the judgment module determines that gear correction is required;

[0040] The current driving mode is hybrid mode;

[0041] The engine speed is less than a first preset speed;

[0042] The vehicle acceleration is less than a first preset acceleration threshold;

[0043] If the brake pedal is in a brake-pressed state, the vehicle acceleration is greater than a second preset acceleration threshold, and the first preset acceleration threshold is greater than the second preset acceleration threshold;

[0044] The accelerator pedal opening is less than a first opening threshold.

[0045] Furthermore, if any of the following conditions are met, the judgment module determines that gear correction is not required;

[0046] The current driving mode is not hybrid;

[0047] The engine speed is greater than a second preset speed, and the second preset speed is greater than the first preset speed;

[0048] The vehicle acceleration is greater than a third preset acceleration threshold;

[0049] The accelerator pedal opening is greater than a second opening threshold, and the second opening threshold is greater than the first opening threshold;

[0050] The first preset acceleration threshold is smaller than the third preset acceleration threshold.

[0051] Furthermore, the method for obtaining the corresponding upshift position according to the current vehicle speed based on the upshift map is as follows:

[0052] According to the vehicle speed coordinate axis of the upshift map, the first vehicle speed value greater than the current vehicle speed is searched in ascending order, and the gear position value corresponding to the vehicle speed value is obtained, and the gear position is the upshift gear position.

[0053] Furthermore, the method for obtaining the corresponding downshift position according to the current vehicle speed based on the downshift map is as follows:

[0054] According to the vehicle speed coordinate axis of the downshift map, the first vehicle speed value that is less than the current vehicle speed is searched in descending order, and the gear position corresponding to the vehicle speed value is obtained, and the gear position is the downshift gear position.

[0055] Beneficial effects of the present invention:

[0056] The present invention corrects the gear position of the motor after the engine is shut down, thereby improving the motor operating efficiency of the P2 configuration hybrid vehicle when driving in a hybrid mode, thereby improving the economy of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A flow chart of the method of the present invention;

[0058] Figure 2 2 is a structural diagram of the system of the present invention.

[0059] Among them, 1-judgment module; 2-first execution module; 3-second execution module. DETAILED DESCRIPTION

[0060] The following will describe the implementation of the technical solution of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for the purpose of illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0061] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0062] This embodiment proposes a method for obtaining the target gear of a hybrid vehicle, which is mainly divided into three steps. The first step is to determine whether the gear shift map needs to be corrected, which is mainly based on whether the engine has been stopped and the motor is driving the vehicle alone. The second step is to calculate the target gear correction value. The third step is to use the target gear correction value to correct the target gear so that the motor works in a more economical speed and torque range. If the target gear correction is not required, the target gear is obtained by querying the basic gear shift map. Specifically, Figure 1 As shown, the specific method is:

[0063] S1: Determine whether gear correction is required.

[0064] When the current vehicle does not need gear correction, if all the following conditions are met at the same time and continue for the set time, it is determined that the vehicle needs gear correction. The following conditions are:

[0065] The current driving mode is hybrid mode;

[0066] The engine speed is less than a first preset speed;

[0067] The vehicle acceleration is less than a first preset acceleration threshold;

[0068] If the brake pedal is in a depressed state and the vehicle acceleration is greater than a second preset acceleration threshold;

[0069] The accelerator pedal opening is less than a first opening threshold.

[0070] When the vehicle is in a state where gear correction is required, if any of the following conditions are met, it is determined that gear correction is not required, specifically:

[0071] The current driving mode is not hybrid;

[0072] The engine speed is greater than a second preset speed, and the second preset speed is greater than the first preset speed;

[0073] The vehicle acceleration is greater than a third preset acceleration threshold;

[0074] The accelerator pedal opening is greater than a second opening threshold.

[0075] S2: If correction is required, the target gear is determined in the following manner:

[0076] Based on the upshift map, according to the vehicle speed coordinate axis of the upshift map, in ascending order, find the first vehicle speed value that is greater than the current vehicle speed, and obtain the gear value corresponding to the speed value. Then the gear position is the upshift gear, thereby realizing the acquisition of the corresponding upshift gear through the current vehicle speed.

[0077] Based on the downshift map, according to the vehicle speed coordinate axis of the downshift map, in descending order, find the first vehicle speed value that is less than the current vehicle speed, and obtain the gear value corresponding to the speed value. Then the gear position is the downshift gear, thereby realizing the acquisition of the corresponding downshift gear through the current vehicle speed.

[0078] Compare the current gear with the upshift gear, let the larger value be the middle gear, then compare the middle gear with the downshift gear, let the smaller value be the target gear.

[0079] If no correction is required, the target gear is determined in the following manner:

[0080] The target gear is obtained based on the preset basic gear shift map according to the current throttle and vehicle speed. Multiple basic gear shift maps are preset in the vehicle system. The current basic gear shift map is selected according to the current vehicle condition, road condition, and vehicle usage environment, and the target gear is obtained by querying the basic gear shift map based on the two parameters of throttle and vehicle speed.

[0081] The two-dimensional tables of the upshift map and the downshift map are both two-dimensional tables based on the throttle and the gear position, and have two parameters: the gear position and the throttle.

[0082] The upshift map, downshift map and basic shift map in this embodiment are all maps of the prior art, wherein:

[0083] The upshift map indicates the vehicle speed value used to determine whether an upshift is required.

[0084] Downshift map indicates the vehicle speed value used to determine whether downshift is required

[0085] The basic shift map indicates the vehicle speed value used to determine whether an upshift or downshift is required, and is used when target gear correction is not required.

[0086] In this embodiment, the second opening threshold is greater than the first opening threshold, and the first preset acceleration threshold is greater than the second preset acceleration threshold.

[0087] This embodiment also proposes a hybrid electric vehicle target gear acquisition system, such as Figure 2 As shown, based on the above method, including:

[0088] A judgment module 1 is configured to judge whether a gear correction is required;

[0089] The first execution module 2 is configured to determine the target gear position in the following manner if correction is required:

[0090] Based on the upshift map, the corresponding upshift position is obtained according to the current vehicle speed;

[0091] Based on the downshift map, the corresponding downshift gear is obtained according to the current vehicle speed;

[0092] Compare the current gear with the upshift gear, let the larger value be the middle gear, then compare the middle gear with the downshift gear, let the smaller value be the target gear;

[0093] The second execution module 3 is configured to determine the target gear position in the following manner if no correction is required:

[0094] The target gear is obtained based on the preset basic shift map according to the current throttle and vehicle speed.

[0095] The judgment method of the judgment module 1 is based on the above description and will not be repeated here.

[0096] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A method for obtaining a target gear position of a hybrid electric vehicle, characterized by: The method is: Determine whether gear correction is required; When all of the following conditions are met simultaneously and for a set period of time, it is determined that gear correction is required; The current driving mode is hybrid mode; The engine speed is less than a first preset speed; The vehicle acceleration is less than a first preset acceleration threshold; If the brake pedal is in a brake-pressed state, the vehicle acceleration is greater than a second preset acceleration threshold, and the first preset acceleration threshold is greater than the second preset acceleration threshold; The accelerator pedal opening is less than a first opening threshold; If any of the following conditions are met, it is determined that gear correction is not required; The current driving mode is not hybrid; The engine speed is greater than a second preset speed, and the second preset speed is greater than the first preset speed; The vehicle acceleration is greater than a third preset acceleration threshold; The accelerator pedal opening is greater than a second opening threshold, and the second opening threshold is greater than the first opening threshold; The first preset acceleration threshold is less than the third preset acceleration threshold; If correction is required, the target gear is determined in the following manner: Based on the upshift map, the corresponding upshift position is obtained according to the current vehicle speed; Based on the downshift map, the corresponding downshift gear is obtained according to the current vehicle speed; Compare the current gear with the upshift gear, let the larger value be the middle gear, then compare the middle gear with the downshift gear, let the smaller value be the target gear; If no correction is required, the target gear is determined in the following manner: The target gear is obtained based on the preset basic shift map according to the current throttle and vehicle speed.

2. The method according to claim 1, wherein: The method for obtaining the corresponding upshift position according to the current vehicle speed based on the upshift map is as follows: According to the vehicle speed coordinate axis of the upshift map, the first vehicle speed value greater than the current vehicle speed is searched in ascending order, and the gear position value corresponding to the vehicle speed value is obtained, and the gear position is the upshift gear position.

3. The method according to claim 1, wherein: The method for obtaining the corresponding downshift position according to the current vehicle speed based on the downshift map is as follows: According to the vehicle speed coordinate axis of the downshift map, the first vehicle speed value that is less than the current vehicle speed is searched in descending order, and the gear position corresponding to the vehicle speed value is obtained, and the gear position is the downshift gear position.

4. A hybrid electric vehicle target gear acquisition system, characterized by: include: A judgment module configured to judge whether a gear correction is required; When all of the following conditions are met simultaneously and continue for a set time, the judgment module determines that gear correction is required; The current driving mode is hybrid mode; The engine speed is less than a first preset speed; The vehicle acceleration is less than a first preset acceleration threshold; If the brake pedal is in a brake-pressed state, the vehicle acceleration is greater than a second preset acceleration threshold, and the first preset acceleration threshold is greater than the second preset acceleration threshold; The accelerator pedal opening is less than a first opening threshold; If any of the following conditions are met, the judgment module determines that gear correction is not required; The current driving mode is not hybrid; The engine speed is greater than a second preset speed, and the second preset speed is greater than the first preset speed; The vehicle acceleration is greater than a third preset acceleration threshold; The accelerator pedal opening is greater than a second opening threshold, and the second opening threshold is greater than the first opening threshold; The first preset acceleration threshold is less than the third preset acceleration threshold; The first execution module is configured to determine the target gear position in the following manner if correction is required: Based on the upshift map, the corresponding upshift position is obtained according to the current vehicle speed; Based on the downshift map, the corresponding downshift gear is obtained according to the current vehicle speed; Compare the current gear with the upshift gear, let the larger value be the middle gear, then compare the middle gear with the downshift gear, let the smaller value be the target gear; The second execution module is configured to determine the target gear position in the following manner if no correction is required: The target gear is obtained based on the preset basic shift map according to the current throttle and vehicle speed.

5. The system according to claim 4, characterized in that: The method for obtaining the corresponding upshift position according to the current vehicle speed based on the upshift map is as follows: According to the vehicle speed coordinate axis of the upshift map, the first vehicle speed value greater than the current vehicle speed is searched in ascending order, and the gear position value corresponding to the vehicle speed value is obtained, and the gear position is the upshift gear position.

6. The system according to claim 4, characterized in that: The method for obtaining the corresponding downshift position according to the current vehicle speed based on the downshift map is as follows: According to the vehicle speed coordinate axis of the downshift map, the first vehicle speed value that is less than the current vehicle speed is searched in descending order, and the gear position corresponding to the vehicle speed value is obtained, and the gear position is the downshift gear position.

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