A manual / automatic shift control method based on electric light trucks

Abstract

This invention discloses a manual / automatic shifting control method for electric light trucks, comprising: calculating the resistance torque borne by the transmission based on the vehicle speed requirements under different loads and gradients; determining the motor's speed range and torque range based on motor performance and transmission speed ratio; and determining the transmission gear based on the relationship between the motor's output torque and the transmission's resistance torque. This invention's manual / automatic shifting control method for electric light trucks designs a set of control strategies for automatic and manual shifting of multi-speed transmissions in electric light trucks, solving the shifting problem of electric light trucks under different loads, road conditions, and vehicle speeds. This ensures that the vehicle can meet power and passability requirements while maintaining motor performance under different road conditions; it also allows the motor to always operate in its maximum efficiency range, reducing drive energy consumption and thus increasing driving range.

Description

Technical Field

[0001] This invention relates to the field of electric light truck technology, and in particular to a manual / automatic shift control method based on an electric light truck. Background Technology

[0002] Most existing new energy vehicles on the market use direct-drive motors, a type of drive widely used in passenger cars and low-tonnage trucks. Direct-drive motors can meet the torque requirements of these vehicles at low speeds and on inclines. However, for large-tonnage electric light and heavy trucks, their significant total vehicle mass far exceeds the capabilities of direct-drive motors on the market. Direct-drive alone cannot meet the power demands of these vehicles at low speeds and on inclines. To improve vehicle starting performance and hill-start assist, a gearbox needs to be added between the motor and the drive axle to enhance the motor's torque output at low speeds. Furthermore, for low-tonnage light trucks requiring higher passability and stronger starting capabilities, multi-speed gearboxes are also a necessary choice.

[0003] However, existing multi-gear transmissions rely on fixed shift motor speeds to switch gears, and are mostly automatic transmissions. This strategy cannot simultaneously meet the driving needs of vehicles of different tonnage on both flat and inclines. This can lead to the following problems: during inclines, inappropriate gear selection results in frequent shifting between high and low gears; during inclines, prolonged high-gear, high-torque, low-speed operation can cause motor overheating; and during flat driving, inappropriate gear selection can result in insufficient power, long acceleration times, long shift times, and shift jerking, among other issues.

[0004] Therefore, there is an urgent need for a manual / automatic shifting control method based on electric light trucks. Summary of the Invention

[0005] The purpose of this invention is to provide a manual-automatic shift control method based on an electric light truck to solve the problems in the prior art, and to meet the requirements of power and passability while ensuring the performance of the motor when the vehicle is driving under different road conditions.

[0006] This invention provides a manual / automatic shift control method based on an electric light truck, comprising:

[0007] The resistance torque that the transmission must withstand is calculated based on the vehicle speed requirements when passing through different gradients under different loads.

[0008] The motor's speed range and torque range are determined based on the motor's performance and the gearbox ratio.

[0009] The gearbox gear is determined based on the relationship between the motor's output torque and the resistance torque borne by the gearbox.

[0010] The manual / automatic shift control method for electric light trucks described above, preferably, involves calculating the resistance torque borne by the transmission based on the vehicle speed requirements under different loads and gradients, specifically including:

[0011] Calculate the vehicle's coasting resistance torque based at least on the vehicle's target speed and the reduction ratio of the rear axle.

[0012] Calculate the climbing resistance torque of the vehicle based at least on the vehicle load mass, the slope value, and the reduction ratio of the rear axle.

[0013] Based on the vehicle's coasting resistance torque and its climbing resistance torque, calculate the total resistance torque of the vehicle passing through ramps with different gradients under different loads.

[0014] The manual / automatic shift control method for electric light trucks described above, preferably, includes the following step: calculating the vehicle's coasting resistance torque based at least on the vehicle's target speed and the rear axle reduction ratio.

[0015] Based on the vehicle's target speed, rear axle reduction ratio, coasting drag coefficient, and tire rolling radius, the vehicle's coasting drag torque is calculated using the following formula:

[0016]

[0017] Among them, T 行 The values ​​represent the vehicle's coasting resistance torque in N·m; F0, F1, and F2 represent the coasting resistance coefficients in N / (km / h); R represents the tire rolling radius in m; V represents the vehicle's target speed in km / h; and I0 represents the vehicle's rear axle reduction ratio.

[0018] The manual / automatic shift control method for electric light trucks described above, preferably, involves calculating the climbing resistance torque of the vehicle based at least on the vehicle load mass, the gradient, and the rear axle reduction ratio, specifically including:

[0019] Calculate the climbing resistance torque of the vehicle based on the vehicle's load mass, gradient, and rear axle reduction ratio:

[0020]

[0021] Among them, T 坡 The slope resistance torque for the vehicle climbing the hill is expressed in N·m; m represents the vehicle load mass in kg; θ represents the slope gradient; I0 ​​represents the rear axle reduction ratio; and R represents the tire rolling radius in m.

[0022] The manual / automatic shifting control method for electric light trucks described above, preferably, involves calculating the total resistance torque of the vehicle traversing slopes with different gradients under different loads, based on the vehicle's coasting resistance torque and its climbing resistance torque. Specifically, this includes:

[0023] Based on the vehicle's coasting resistance torque under different loads and the vehicle's climbing resistance torque when climbing slopes with different loads and gradients, the total resistance torque of the vehicle traversing different slopes under different loads is calculated using the following formula:

[0024] T 总 =T 行 +T 坡 (3)

[0025] T 总 This represents the total resistance torque that the transmission needs to overcome when a vehicle passes through slopes of different gradients under different loads, expressed in N·m (T). 行 This represents the vehicle's coasting resistance torque, measured in N·m (T). 坡 This represents the slope resistance torque for a vehicle climbing a hill, expressed in N·m.

[0026] The manual / automatic shifting control method for electric light trucks described above, preferably, involves determining the motor's speed range and torque range based on motor performance and gearbox ratio, specifically including:

[0027] Based on the target vehicle speed, calculate the motor speed and output torque of the vehicle under different gearbox ratios.

[0028] The manual / automatic shift control method for electric light trucks described above, preferably, involves calculating the motor speed and output torque of the vehicle at different gearbox ratios based on the target vehicle speed, specifically including:

[0029] At least based on the vehicle's target speed and the gear ratio of the transmission, calculate the motor speed of the vehicle at different transmission ratios;

[0030] At least the motor torque value of the vehicle at different gearbox ratios should be calculated based on the motor speed at different gearbox ratios.

[0031] The manual / automatic shift control method for electric light trucks described above, preferably, includes the following step: calculating the motor speed of the vehicle at different gear ratios based at least on the target vehicle speed and the gear ratio of the transmission.

[0032] Based on the vehicle's target speed, gearbox gear ratio, rear axle reduction ratio, and tire rolling radius, the motor speed of the vehicle at different gearbox gear ratios is calculated using the following formula:

[0033]

[0034] Where V represents the target vehicle speed in km / h, n represents the motor speed in rpm, R represents the tire rolling radius in m, I0 represents the rear axle reduction ratio, and I represents the gear ratio of the transmission.

[0035] The manual / automatic shift control method for electric light trucks described above, preferably, involves calculating the motor torque values ​​at different gearbox ratios based at least on the motor speeds at different gearbox ratios, specifically including:

[0036] Based on the motor speed and rated power of the vehicle at different gearbox ratios, the motor torque value corresponding to different gears is calculated using the following formula:

[0037]

[0038] Where T represents the motor torque value in N·m, P represents the motor power in kW, and n represents the motor speed in rpm.

[0039] The manual / automatic shifting control method for electric light trucks described above, preferably, involves determining the gearbox gear based on the relationship between the motor's output torque and the resistance torque borne by the gearbox, specifically including:

[0040] The table lists the motor torque and motor speed corresponding to different gearbox ratios;

[0041] Use the following formula to look up the table and determine the candidate gearbox ratios that meet the requirements:

[0042] T≥T 总 ×1.3 (6)

[0043] Where T represents the motor output torque, T 总 This represents the total resistance torque that the transmission needs to overcome when the vehicle passes through slopes of different gradients under different loads. 1.3 represents an empirical coefficient.

[0044] Among all the candidate gear ratios that meet the requirements, a gear ratio is selected according to a preset gear selection principle, and the gear corresponding to the selected gear ratio is used as the current gear.

[0045] The preset gear selection principle includes:

[0046] In automatic mode, if the motor speed and torque corresponding to multiple gear ratios meet the requirements, the gear with the smaller gear ratio is selected as the current gear.

[0047] In manual mode, the shifting range is limited to the gears corresponding to the candidate gearbox ratio.

[0048] This invention provides a manual / automatic shifting control method for electric light trucks. It designs a control strategy for automatic and manual shifting of multi-speed gearboxes in electric light trucks. The method calculates the resistance value borne by the gearbox based on the vehicle speed requirements under different loads and gradients. Then, based on the motor performance and gearbox ratio, it calculates the motor's speed and torque range, thereby selecting the appropriate gearbox gear. This solves the shifting problem of electric light trucks under different loads, road conditions, and vehicle speeds, ensuring that the vehicle meets power and passability requirements while maintaining motor performance under various road conditions. It allows the motor to always operate in its maximum efficiency range, reducing drive energy consumption and thus increasing driving range. Based on current practical conditions, this method can be implemented in actual electric light trucks, and data on different vehicle models, motors, and gearboxes can be collected and accumulated for continuous optimization and improvement of shifting strategies in future products. Attached Figure Description

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0050] Figure 1 A flowchart illustrating an embodiment of the manual / automatic shift control method for electric light trucks provided by the present invention. Detailed Implementation

[0051] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0052] The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Terms such as “including” or “contains” mean that the element preceding the term encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as “above” and “below” are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0053] In this disclosure, when a specific component is described as being located between a first component and a second component, an intermediary component may or may not be present between the specific component and the first or second component. When a specific component is described as connecting to other components, the specific component may be directly connected to the other components without having an intermediary component, or it may not be directly connected to the other components but may have an intermediary component.

[0054] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0055] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0056] As shown in Table 1, the traditional shifting strategy involves a motor with a rated speed of N1 and a four-speed transmission (M1, M2, M3, M4). Existing multi-speed automatic transmissions use the motor's rated speed (N1) as the upshift point and half of that speed (N1 / 2) as the downshift point. In contrast, manual transmissions use the fixed shift points of automatic transmissions to determine the current gear. When switching from automatic to manual, the transmission shifts to the corresponding gear based on the current motor speed, without considering the overall vehicle power requirements.

[0057] Table 1 Traditional shifting strategies

[0058]

[0059] For electric light trucks, a fixed shift point can only meet the driving needs of a certain load on flat roads or slopes, and cannot achieve compatibility. This easily leads to the following common problems: When driving on a slope, if the torque required for climbing is sufficient for the transmission in 2nd gear but insufficient in 3rd gear, the transmission will repeatedly switch between 2nd and 3rd gear during the climb. This not only results in a poor driving experience but also causes the motor to experience overcurrent and overheating due to overload output in 3rd gear. Alternatively, if the transmission can meet the torque requirements for climbing in 3rd gear, but the motor needs to output peak torque, this can lead to overheating due to prolonged high torque output. On flat roads, if the transmission shifts at a fixed shift point, two problems are likely to occur: if the shift point is too high, shifting will result in jerky shifts, affecting the driving experience; if the shift point is too low, insufficient power and long acceleration times will also negatively impact the user's driving experience.

[0060] like Figure 1 As shown, the manual / automatic shift control method based on an electric light truck provided in this embodiment includes the following steps in actual execution:

[0061] Step S1: Calculate the resistance torque that the transmission must withstand based on the vehicle speed requirements when passing through different slopes under different loads.

[0062] In step S1, based on the vehicle speed requirements in the design objectives, the resistance torque of the vehicle under different loads and traversing different gradients is calculated. In one embodiment of the manual-automatic shift control method for electric light trucks of the present invention, step S1 may specifically include:

[0063] Step S11: Calculate the vehicle's sliding resistance torque based at least on the vehicle's target speed and the vehicle's rear axle reduction ratio.

[0064] Specifically, based on the vehicle's target speed, rear axle reduction ratio, coasting drag coefficient, and tire rolling radius, the vehicle's coasting drag torque is calculated using the following formula:

[0065]

[0066] Among them, T 行 The values ​​represent the vehicle's coasting resistance torque in N·m; F0, F1, and F2 represent the coasting resistance coefficients in N / (km / h); R represents the tire rolling radius in m; V represents the vehicle's target speed in km / h; and I0 represents the vehicle's rear axle reduction ratio.

[0067] Step S12: Calculate the climbing resistance torque of the vehicle based at least on the vehicle load mass, the slope value, and the vehicle rear axle reduction ratio.

[0068] Specifically, the climbing resistance torque of the vehicle is calculated based on the vehicle's load mass, the gradient, and the reduction ratio of the rear axle.

[0069]

[0070] Among them, T 坡 The slope resistance torque for the vehicle climbing the hill is expressed in N·m; m represents the vehicle load mass in kg; θ represents the slope gradient; I0 ​​represents the rear axle reduction ratio; and R represents the tire rolling radius in m.

[0071] Step S13: Calculate the total resistance torque of the vehicle passing through ramps with different gradients under different loads, based on the vehicle's coasting resistance torque and the vehicle's climbing resistance torque.

[0072] Specifically, based on the vehicle's coasting resistance torque under different loads and the vehicle's climbing resistance torque on slopes with different loads and gradients, the total resistance torque of the vehicle traversing different slopes under different loads is calculated using the following formula:

[0073] T 总 =T 行 +T 坡 (3)

[0074] T 总 This represents the total resistance torque that the transmission needs to overcome when a vehicle passes through slopes of different gradients under different loads, expressed in N·m (T). 行 This represents the vehicle's coasting resistance torque, measured in N·m (T). 坡 This represents the slope resistance torque for a vehicle climbing a hill, expressed in N·m.

[0075] Step S2: Determine the motor's speed range and torque range based on the motor's performance and the gearbox's speed ratio.

[0076] In this invention, the motor speed and output torque of the vehicle under different gearbox ratios are calculated based on the target vehicle speed. In one embodiment of the manual-automatic shift control method for electric light trucks of this invention, step S2 may specifically include:

[0077] Step S21: Calculate the motor speed of the vehicle at different gearbox ratios, based at least on the target vehicle speed and the gearbox gear ratio.

[0078] Specifically, based on the vehicle's target speed, gearbox gear ratio, rear axle reduction ratio, and tire rolling radius, the motor speed of the vehicle at different gearbox gear ratios is calculated using the following formula:

[0079]

[0080] Where V represents the target vehicle speed in km / h, n represents the motor speed in rpm, R represents the tire rolling radius in m, I0 represents the rear axle reduction ratio, and I represents the gear ratio of the transmission.

[0081] Step S22: Calculate the motor torque value of the vehicle at different gearbox ratios, based at least on the motor speed of the vehicle at different gearbox ratios.

[0082] Specifically, based on the motor speed and rated power of the vehicle at different gear ratios, the motor torque value corresponding to different gears is calculated using the following formula:

[0083]

[0084] Where T represents the motor torque value in N·m, P represents the motor power in kW, and n represents the motor speed in rpm.

[0085] Step S3: Determine the gearbox gear based on the relationship between the motor's output torque and the resistance torque borne by the gearbox.

[0086] In one embodiment of the manual / automatic shift control method for electric light trucks of the present invention, step S3 may specifically include:

[0087] Step S31: As shown in Table 2, list the motor torque and motor speed corresponding to different gearbox ratios in the table.

[0088] Table 2. Motor torque and motor speed corresponding to different gearbox ratios.

[0089] gearbox ratio I1 I2 I3 I4 motor speed n1 n2 n3 n4 Motor torque T1 T2 T3 T4

[0090] Step S32: Determine the candidate gearbox ratios that meet the requirements by referring to the table using the following formula:

[0091] T≥T 总 ×1.3 (6)

[0092] Where T represents the output torque of the motor, Ttotal represents the total resistance torque that the transmission needs to overcome when the vehicle passes through slopes of different gradients under different loads, and 1.3 represents an empirical coefficient.

[0093] In step S32, the appropriate gear ratio of the gearbox is selected based on the motor output torque being greater than or equal to 1.3 times the resistance torque, according to the output characteristics of the motor.

[0094] Step S33: Among all the candidate gear ratios that meet the requirements, select a gear ratio according to the preset gear selection principle, and use the gear corresponding to the selected gear ratio as the current gear.

[0095] The preset gear selection principle includes:

[0096] In automatic mode, if the motor speed and torque corresponding to multiple gear ratios meet the requirements, the gear with the smaller gear ratio is selected as the current gear.

[0097] In manual mode, for the protection and safety of the motor, the shifting range is limited to the gears corresponding to the candidate gearbox ratio.

[0098] This invention enables the vehicle to select an appropriate gearbox gear as the automatic transmission gear based on parameters such as current load, driving gradient, and vehicle speed requirements, combined with the output characteristics of the motor. By restricting the switching conditions of manual gears, it can prevent the vehicle from failing to meet the passability requirements due to insufficient power in high gears. It can meet the power requirements of the vehicle when climbing hills and driving on flat roads. By flexibly adjusting the gearbox gear according to the motor torque characteristics, it avoids a series of problems such as insufficient power caused by the traditional fixed shift motor speed point.

[0099] The automatic / manual shifting control method for electric light trucks provided in this invention designs a set of control strategies for automatic and manual shifting of multi-speed gearboxes in electric light trucks. It calculates the resistance value borne by the gearbox based on the vehicle speed requirements under different loads and gradients; then, based on the motor performance and gearbox ratio, it calculates the motor's speed and torque range, thereby selecting the appropriate gearbox gear. This solves the shifting problem of electric light trucks under different loads, road conditions, and vehicle speeds, ensuring that the vehicle meets the power and passability requirements while maintaining motor performance under different road conditions. It allows the motor to always operate in its maximum efficiency range, reducing drive energy consumption and thus increasing driving range. Based on current practical conditions, this method can be implemented in actual electric light trucks, and data on different models, motors, and gearboxes can be collected and accumulated for continuous optimization and improvement of shifting strategies in subsequent products.

[0100] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0101] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A manual / automatic shifting control method based on an electric light truck, characterized in that, include: The resistance torque that the transmission must withstand is calculated based on the vehicle speed requirements when passing through different gradients under different loads. The motor's speed range and torque range are determined based on the motor's performance and the gearbox ratio. The gearbox gear is determined based on the relationship between the motor's output torque and the resistance torque experienced by the gearbox. The process of determining the gearbox gear based on the relationship between the motor's output torque and the resistance torque borne by the gearbox specifically includes: The table lists the motor torque and motor speed corresponding to different gearbox ratios; Use the following formula to look up the table and determine the candidate gearbox ratios that meet the requirements: （1） Where T represents the motor output torque, T 总 This represents the total resistance torque that the transmission needs to overcome when the vehicle passes through slopes of different gradients under different loads. 1.3 represents an empirical coefficient. Among all the candidate gear ratios that meet the requirements, a gear ratio is selected according to a preset gear selection principle, and the gear corresponding to the selected gear ratio is used as the current gear. The preset gear selection principle includes: In automatic mode, if the motor speed and torque corresponding to multiple gear ratios meet the requirements, the gear with the smaller gear ratio is selected as the current gear. In manual mode, the shifting range is limited to the gears corresponding to the candidate gearbox ratio.

2. The manual / automatic shifting control method based on an electric light truck according to claim 1, characterized in that, The calculation of the resistance torque borne by the transmission based on the vehicle speed requirements under different loads and gradients specifically includes: Calculate the vehicle's coasting resistance torque based at least on the vehicle's target speed and the reduction ratio of the rear axle. Calculate the climbing resistance torque of the vehicle based at least on the vehicle load mass, the slope value, and the reduction ratio of the rear axle. Based on the vehicle's coasting resistance torque and its climbing resistance torque, calculate the total resistance torque of the vehicle passing through ramps with different gradients under different loads.

3. The manual / automatic shifting control method based on an electric light truck according to claim 2, characterized in that, The calculation of the vehicle's coasting resistance torque, based at least on the vehicle's target speed and the rear axle reduction ratio, specifically includes: Based on the vehicle's target speed, rear axle reduction ratio, coasting drag coefficient, and tire rolling radius, the vehicle's coasting drag torque is calculated using the following formula: （2） Among them, T 行 The values ​​represent the vehicle's coasting resistance torque in N·m; F0, F1, and F2 represent the coasting resistance coefficients in N / (km / h); R represents the tire rolling radius in m; V represents the vehicle's target speed in km / h; and I0 represents the vehicle's rear axle reduction ratio.

4. The manual / automatic shifting control method based on an electric light truck according to claim 2, characterized in that, The calculation of the climbing resistance torque of the vehicle, based at least on the vehicle's load mass, the gradient, and the rear axle reduction ratio, specifically includes: Calculate the climbing resistance torque of the vehicle based on the vehicle's load mass, gradient, and rear axle reduction ratio: （3） Among them, T 坡 The slope resistance torque for the vehicle climbing the hill is expressed in N·m; m represents the vehicle load mass in kg; θ represents the slope gradient; I0 ​​represents the rear axle reduction ratio; and R represents the tire rolling radius in m.

5. The manual / automatic shifting control method based on an electric light truck according to claim 2, characterized in that, The calculation of the total resistance torque of the vehicle traversing ramps with different gradients under different loads, based on the vehicle's coasting resistance torque and climbing resistance torque, specifically includes: Based on the vehicle's coasting resistance torque under different loads and the vehicle's climbing resistance torque when climbing slopes with different loads and gradients, the total resistance torque of the vehicle traversing different slopes under different loads is calculated using the following formula: （4） T 总 This represents the total resistance torque that the transmission needs to overcome when a vehicle passes through slopes of different gradients under different loads, expressed in N·m (T). 行 This represents the vehicle's coasting resistance torque, measured in N·m (T). 坡 This represents the slope resistance torque for a vehicle climbing a hill, expressed in N·m.

6. The manual / automatic shifting control method based on an electric light truck according to claim 1, characterized in that, The determination of the motor's speed range and torque range based on motor performance and gearbox ratio specifically includes: Based on the target vehicle speed, calculate the motor speed and output torque of the vehicle under different gearbox ratios.

7. The manual / automatic shifting control method based on an electric light truck according to claim 6, characterized in that, The calculation of the motor speed and output torque of the vehicle under different gearbox ratios based on the target vehicle speed includes: At least based on the vehicle's target speed and the gear ratio of the transmission, calculate the motor speed of the vehicle at different transmission ratios; At least the motor torque value of the vehicle at different gearbox ratios should be calculated based on the motor speed at different gearbox ratios.

8. The manual / automatic shifting control method based on an electric light truck according to claim 7, characterized in that, The calculation of the motor speed of the vehicle at different gear ratios is based at least on the target vehicle speed and the gear ratio of the transmission, specifically including: Based on the vehicle's target speed, gearbox gear ratio, rear axle reduction ratio, and tire rolling radius, the motor speed of the vehicle at different gearbox gear ratios is calculated using the following formula: （5） Where V represents the target vehicle speed in km / h, n represents the motor speed in rpm, R represents the tire rolling radius in m, I0 represents the rear axle reduction ratio, and I represents the gear ratio of the transmission.

9. The manual / automatic shifting control method based on an electric light truck according to claim 7, characterized in that, The calculation of the motor torque value of the vehicle at different gearbox ratios, based at least on the motor speed at different gearbox ratios, specifically includes: Based on the motor speed and rated power of the vehicle at different gearbox ratios, the motor torque value corresponding to different gears is calculated using the following formula: （6） Where T represents the motor torque value in N·m, P represents the motor power in kW, and n represents the motor speed in rpm.

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