Method for improving efficiency of an electric drive system

Abstract

The application provides a method for improving the efficiency of an electric drive system, which collects and analyzes the road surface image of the front road during the driving process of an electric vehicle to determine the existence information of the obstacles in the front road and whether the current driving path of the electric vehicle overlaps with the obstacles; and further obtains the lateral friction information between the wheels of the electric vehicle and the road surface, whether the front road has another driving path allowing the electric vehicle to completely avoid the obstacles, and the three-dimensional size of the obstacles, and adaptively instructs the electric motor of the electric drive system to adjust the torque output to the wheels, so that the electric vehicle can adjust the torque output by the electric motor according to the existence and position of the obstacles during the actual driving process to efficiently convert and utilize the electric energy of the battery of the electric vehicle, thereby improving the stability of the driving of the electric vehicle and saving the electric energy of the battery of the electric vehicle.

Description

Technical Field

[0001] This invention relates to the technical field of electric vehicle control, and in particular to a method for improving the efficiency of electric drive systems. Background Technology

[0002] Electric vehicles (EVs) operate by using an electric drive system with an electric motor to drive the wheels. During operation, EVs inevitably encounter road obstacles. In such cases, the electric motor typically maintains its original output torque. This means the electric drive system cannot adaptively adjust its torque output based on the presence of obstacles, thus hindering battery energy conservation and reducing the system's efficiency in converting battery power into electricity. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for improving the efficiency of electric drive systems. This method collects and analyzes road surface images of the road ahead during the electric vehicle's operation to determine the presence of obstacles and whether there is overlap between the electric vehicle's current path and the obstacles. Furthermore, by acquiring information on the lateral friction between the electric vehicle's wheels and the road surface, whether there is another path ahead allowing the electric vehicle to completely avoid obstacles, and the three-dimensional dimensions of the obstacles, the method adaptively instructs the electric drive system's motor to adjust the torque output to the wheels. This enables the electric vehicle to adjust the motor's torque output based on the presence and location of obstacles during actual driving, thereby efficiently converting and utilizing the electric vehicle's battery energy, improving the smoothness of the electric vehicle's operation, and saving battery energy.

[0004] This invention provides a method for improving the efficiency of an electric drive system, comprising the following steps:

[0005] Step S1: Collect road surface images of the road ahead while the electric vehicle is driving, analyze the road surface images, and determine the existence information of obstacles on the road ahead; based on the obstacle existence information, determine whether there is an overlap between the current driving path of the electric vehicle and the obstacles;

[0006] Step S2: If there is no overlap, obtain the lateral friction force information between the wheels of the electric vehicle and the road surface, and instruct the electric drive system motor to adjust the torque output to the wheels based on the lateral friction force information.

[0007] Step S3: If there is an overlap, analyze the road image to determine if there is another driving path ahead that allows the electric vehicle to completely avoid the obstacle; if there is another driving path, determine the path deviation between the current driving path of the electric vehicle and the other driving path, and instruct the electric drive system's motor to adjust the torque output to the wheels based on the path deviation.

[0008] Step S4: If there is no other driving path, analyze the three-dimensional dimensions of the obstacle and, based on the three-dimensional dimensions, instruct the electric motor of the electric drive system to adjust the torque output to the wheels, so that the wheels of the electric vehicle can smoothly roll over the obstacle.

[0009] Furthermore, in step S1, acquiring road surface images of the road ahead while the electric vehicle is driving, and analyzing the road surface images to determine the presence of obstacles on the road ahead specifically includes:

[0010] The road surface ahead is captured by binocular cameras during the driving of an electric vehicle, thereby obtaining a binocular road surface image; based on the image parallax of the binocular road surface image, a three-dimensional road surface image corresponding to the road ahead is obtained.

[0011] The location information of obstacles on the plane where the road surface is located is identified from the three-dimensional road image;

[0012] Furthermore, in step S1, determining whether there is an overlap between the electric vehicle's current driving path and the obstacle based on the obstacle presence information specifically includes:

[0013] Obtain the current centerline of the electric vehicle and determine the vertical distance between the obstacle and the straight line containing the centerline of the vehicle; if the vertical distance is less than or equal to half the width of the electric vehicle, it is determined that there is an overlap between the current driving path of the electric vehicle and the obstacle; otherwise, it is determined that there is no overlap between the current driving path of the electric vehicle and the obstacle.

[0014] Furthermore, in step S2, if there is no overlap, the lateral friction force information between the electric vehicle's wheels and the road surface is obtained, and based on the lateral friction force information, the electric drive system's motor is instructed to adjust the torque output to the wheels. This specifically includes:

[0015] If there is no overlap, the frictional force information between the wheel and the road surface of the electric vehicle during driving is obtained in the direction perpendicular to the wheel hub surface, and this is used as the lateral frictional force information.

[0016] The lateral friction force value corresponding to the lateral friction force information is compared with a preset friction force threshold. If the lateral friction force value is less than or equal to the preset friction force threshold, the electric drive system motor is instructed to maintain the current torque output to the wheel. If the lateral friction force value is greater than or equal to the preset friction force threshold, the electric drive system motor is instructed to increase the torque output to the wheel in the direction opposite to the lateral friction force.

[0017] Furthermore, in step S3, if there is overlap, the road surface image is analyzed to determine whether there is another driving path ahead that allows the electric vehicle to completely avoid the obstacle. This specifically includes:

[0018] If there is overlap, the width of the free road surface corresponding to the left or right side of the obstacle is identified from the three-dimensional road surface image;

[0019] The width of the free road surface corresponding to the left or right side of the obstacle is compared with the width of the electric vehicle. If the width of the free road surface is greater than the width of the vehicle body, it is determined that there is another driving path on the left or right side of the obstacle that allows the electric vehicle to completely avoid the obstacle; otherwise, it is determined that there is no other driving path on the left or right side of the obstacle that allows the electric vehicle to completely avoid the obstacle.

[0020] Furthermore, in step S3, if another driving path exists, the path deviation between the current driving path of the electric vehicle and the other driving path is determined, and based on the path deviation, the electric drive system's motor is instructed to adjust the torque output to the wheels. This specifically includes:

[0021] If another driving path exists, the path direction deviation between the current driving path of the electric vehicle and the other driving path is determined, and the magnitude and direction of the torque output by the electric motor of the electric drive system to the wheels and the steering angle of the front wheels of the electric vehicle are adjusted according to the path direction deviation, so that the overall driving of the electric vehicle switches to the other driving path.

[0022] Furthermore, in step S3, determining the path direction deviation between the current driving path of the electric vehicle and another driving path, and adjusting the magnitude and direction of the torque output by the electric motor of the electric drive system to the wheels and the steering angle of the front wheels of the electric vehicle based on the path direction deviation, thereby switching the overall driving of the electric vehicle to another driving path, specifically includes:

[0023] Step S301: Using the formula (1) below, based on the vector representation of the current driving path of the electric vehicle and the vector representation of another driving path, obtain the path direction deviation between the current driving path and the other driving path.

[0024]

[0025] In the above formula (1), L represents the path direction deviation between the current driving path of the electric vehicle and another driving path; (X e -x0,Y e -y0) represents the direction vector of the electric vehicle's current driving path from the starting point of the path to the current position of the electric vehicle; (X c -x0,Y c (x0, y0) represents the direction vector of another driving path from its starting point to the closest position on that path to the electric vehicle; (x0, y0) represents the coordinates of the starting point of the driving path; (X e ,Y e (X) represents the current position coordinates of the electric vehicle; c ,Y c ) represents the coordinates of the position closest to the electric vehicle on the other driving path; · represents the vector dot product operation; | represents the operation of calculating the vector magnitude;

[0026] Step S302: Using formula (2) below, adjust the steering angle of the electric vehicle's front wheels based on the path direction deviation between the current driving path and another driving path.

[0027]

[0028] In formula (2) above, θ represents the steering angle of the front wheels of the electric vehicle; θ max This indicates the maximum steering angle within the controllable range of the front wheels of an electric vehicle;

[0029] Step S303: Using the following formula (3), adjust the magnitude and direction of the torque output from the electric motor of the electric drive system to the wheels based on the path direction deviation between the current driving path and another driving path.

[0030] ΔM=F×tanθ×R (3)

[0031] In the above formula (3), ΔM represents the adjustment amount of the torque output by the electric motor of the electric drive system to the wheel; F represents the magnitude of the driving force provided by the electric motor of the electric drive system to the wheel from the starting point to the end point of the path; R represents the wheel radius of the electric vehicle.

[0032] The adjustment amount ΔM of the torque output to the wheels by the electric motor of the electric drive system is used to control the adjustment amount of the torque output to the wheels by the electric motor of the electric drive system, and the adjustment direction is the same as the turning direction of the front wheel of the electric vehicle, so that the overall driving of the electric vehicle switches to another driving path.

[0033] Furthermore, in step S4, if there is no other driving path, the analysis of the three-dimensional dimensions of the obstacle specifically includes:

[0034] If no other driving path exists, the height and maximum width of the obstacle are identified from the three-dimensional road surface image.

[0035] Furthermore, in step S4, based on the three-dimensional dimensions, instructing the electric drive system's motor to adjust the torque output to the wheels, thereby enabling the electric vehicle's wheels to smoothly roll over obstacles, specifically includes:

[0036] If the height of the obstacle is greater than or equal to a threshold height threshold and the maximum width is greater than or equal to a threshold width threshold, the electric drive system's motor is instructed to reduce the torque output to the wheels; otherwise, the electric drive system's motor is instructed to maintain the current torque output to the wheels, thereby enabling the electric vehicle's wheels to smoothly roll over the obstacle.

[0037] Compared to existing technologies, this method for improving the efficiency of an electric drive system collects and analyzes road surface images of the road ahead during the electric vehicle's operation. This determines the presence of obstacles ahead and whether there is any overlap between the electric vehicle's current driving path and the obstacles. Furthermore, by acquiring information on the lateral friction between the electric vehicle's wheels and the road surface, whether there is another driving path ahead that allows the electric vehicle to completely avoid obstacles, and the three-dimensional dimensions of the obstacles, the system adaptively instructs the electric drive system's motor to adjust the torque output to the wheels. This enables the electric vehicle to adjust the motor's output torque based on the presence and location of obstacles during actual driving, thereby efficiently converting and utilizing the electric vehicle's battery energy, improving the smoothness of the electric vehicle's driving, and saving the electric vehicle's battery energy.

[0038] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0039] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0041] Figure 1A flowchart illustrating the efficiency improvement method for an electric drive system provided by the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0043] See Figure 1 This is a flowchart illustrating a method for improving the efficiency of an electric drive system according to an embodiment of the present invention. The method for improving the efficiency of an electric drive system includes the following steps:

[0044] Step S1: Collect road surface images of the road ahead while the electric vehicle is driving, analyze the road surface images to determine the existence of obstacles on the road ahead; based on the obstacle existence information, determine whether there is any overlap between the current driving path of the electric vehicle and the obstacles.

[0045] Step S2: If there is no overlap, obtain the lateral friction force information between the wheels of the electric vehicle and the road surface, and instruct the electric drive system's motor to adjust the torque output to the wheels based on the lateral friction force information.

[0046] Step S3: If there is an overlap, analyze the road image to determine if there is another driving path ahead that allows the electric vehicle to completely avoid the obstacle; if there is another driving path, determine the path deviation between the current driving path of the electric vehicle and the other driving path, and based on the path deviation, instruct the electric drive system's motor to adjust the torque output to the wheels.

[0047] In step S4, if there is no other driving path, the three-dimensional dimensions of the obstacle are analyzed, and based on the three-dimensional dimensions, the electric motor of the electric drive system is instructed to adjust the torque output to the wheels, so that the wheels of the electric vehicle can smoothly roll over the obstacle.

[0048] The beneficial effects of the above technical solution are as follows: The efficiency improvement method of the electric drive system collects and analyzes the road surface image of the road ahead during the electric vehicle's driving process, thereby determining the existence information of obstacles on the road ahead and whether there is any overlap between the electric vehicle's current driving path and the obstacles; and by acquiring the lateral friction force information between the electric vehicle's wheels and the road surface, whether there is another driving path on the road ahead that allows the electric vehicle to completely avoid obstacles, and the three-dimensional dimensions of the obstacles, it adaptively instructs the electric drive system's motor to adjust the torque output to the wheels. This enables the electric vehicle to adjust the motor's output torque according to the presence and location of obstacles during actual driving, so as to efficiently convert and utilize the electric vehicle's battery energy, thereby improving the stability of the electric vehicle's driving and saving the electric vehicle's battery energy.

[0049] Preferably, in step S1, acquiring road surface images of the road ahead while the electric vehicle is driving, and analyzing these images to determine the presence of obstacles on the road ahead specifically includes:

[0050] The road surface ahead is captured by binocular cameras while the electric vehicle is driving, thereby obtaining a binocular road surface image; based on the image parallax of the binocular road surface image, a three-dimensional road surface image corresponding to the road ahead is obtained.

[0051] The location information of obstacles on the plane of the road surface can be identified from the three-dimensional road image.

[0052] The beneficial effects of the above technical solution are as follows: by using a binocular camera set in front of the electric vehicle to take binocular pictures of the road surface in front of the electric vehicle, a three-dimensional road surface image corresponding to the road surface in front can be obtained. This three-dimensional road surface image contains the location of obstacles on the road ahead, as well as the three-dimensional shape and size information of the obstacles themselves, thereby providing a reliable reference standard for subsequent obstacle avoidance or changing the driving path of the electric vehicle.

[0053] Preferably, in step S1, determining whether there is an overlap between the current driving path of the electric vehicle and the obstacle based on the obstacle existence information specifically includes:

[0054] Obtain the current centerline of the electric vehicle and determine the vertical distance between the obstacle and the straight line containing the centerline. If the vertical distance is less than or equal to half the width of the electric vehicle, it is determined that there is an overlap between the current driving path of the electric vehicle and the obstacle; otherwise, it is determined that there is no overlap between the current driving path of the electric vehicle and the obstacle.

[0055] The beneficial effects of the above technical solution are as follows: when it is determined that there is an obstacle on the road ahead, the coverage area of ​​the electric vehicle's current driving path is determined based on the current centerline of the electric vehicle, and the coverage area of ​​the driving path is compared and matched with the location of the obstacle to determine whether there is an overlap between the two.

[0056] Preferably, in step S2, if there is no overlap, the lateral friction force information between the electric vehicle's wheels and the road surface is obtained, and based on this lateral friction force information, the electric drive system's motor is instructed to adjust the torque output to the wheels. This specifically includes:

[0057] If there is no overlap, the frictional force information between the wheel and the road surface of the electric vehicle during driving is obtained in the direction perpendicular to the wheel hub surface, and this is used as the lateral frictional force information.

[0058] The lateral friction force value corresponding to the lateral friction force information is compared with a preset friction force threshold. If the lateral friction force value is less than or equal to the preset friction force threshold, the electric drive system motor is instructed to maintain the current torque output to the wheel. If the lateral friction force value is greater than or equal to the preset friction force threshold, the electric drive system motor is instructed to increase the torque output to the wheel in the direction opposite to the lateral friction force.

[0059] The beneficial effects of the above technical solution are as follows: When it is determined that there is no overlap between the current driving path of the electric vehicle and the obstacle, it indicates that the electric vehicle will not collide with the obstacle along the current driving path. At this time, the lateral friction force information between the wheels of the electric vehicle and the road surface is obtained. This lateral friction force information is related to the probability of the electric vehicle rolling over; the greater the lateral friction force, the greater the probability of the electric vehicle rolling over. By comparing the lateral friction force value with a preset friction force threshold, if the lateral friction force value is greater than or equal to the preset friction force threshold, the electric drive system's motor is instructed to increase the torque output to the wheels in the direction opposite to the lateral friction force, thereby effectively preventing the electric vehicle from rolling over during driving.

[0060] Preferably, in step S3, if there is overlap, the road surface image is analyzed to determine whether there is another driving path ahead that allows the electric vehicle to completely avoid the obstacle. This specifically includes:

[0061] If there is overlap, the width of the free road surface corresponding to the left or right side of the obstacle can be identified from the three-dimensional road surface image;

[0062] The width of the free road surface corresponding to the left or right side of the obstacle is compared with the width of the electric vehicle. If the width of the free road surface is greater than the width of the vehicle body, it is determined that there is another driving path on the left or right side of the obstacle that allows the electric vehicle to completely avoid the obstacle; otherwise, it is determined that there is no other driving path on the left or right side of the obstacle that allows the electric vehicle to completely avoid the obstacle.

[0063] The beneficial effects of the above technical solution are as follows: When it is determined that there is an overlap between the current driving path of the electric vehicle and an obstacle, the driving path of the electric vehicle can be changed to avoid the obstacle. By recognizing and analyzing the three-dimensional road surface image, the width of the empty road surface to the left or right of the obstacle is determined, and the width of the empty road surface is compared with the width of the electric vehicle body to determine whether the empty road surface to the left or right of the obstacle is sufficient for the electric vehicle to pass normally, so that the electric vehicle can change its driving path in time to avoid the obstacle.

[0064] Preferably, in step S3, determining the path direction deviation between the current driving path of the electric vehicle and another driving path, and adjusting the magnitude and direction of the torque output by the electric motor of the electric drive system to the wheels and the steering angle of the front wheels of the electric vehicle based on the path direction deviation, so that the overall driving of the electric vehicle switches to another driving path, specifically includes:

[0065] Step S301: Using the formula (1) below, based on the vector representation of the current driving path of the electric vehicle and the vector representation of another driving path, obtain the path direction deviation between the current driving path and the other driving path.

[0066]

[0067] In the above formula (1), L represents the path direction deviation between the current driving path of the electric vehicle and another driving path; (X e -x0,Y e -y0) represents the direction vector of the electric vehicle's current driving path from the starting point of the path to the current position of the electric vehicle; (X c -x0,X c (x0, y0) represents the direction vector of another driving path from its starting point to the closest position on that path to the electric vehicle; (x0, y0) represents the coordinates of the starting point of the driving path; (X e ,Y e (X) represents the current position coordinates of the electric vehicle; c ,Y c ) represents the coordinates of the position closest to the electric vehicle on the other driving path; · represents the vector dot product operation; | represents the operation of calculating the magnitude of a vector.

[0068] Step S302: Using formula (2) below, adjust the steering angle of the electric vehicle's front wheels based on the path direction deviation between the current driving path and another driving path.

[0069]

[0070] In formula (2) above, θ represents the steering angle of the front wheels of the electric vehicle; θ max This indicates the maximum steering angle within the controllable range of the front wheels of an electric vehicle;

[0071] Step S303: Using the following formula (3), adjust the magnitude and direction of the torque output from the electric motor of the electric drive system to the wheels based on the path direction deviation between the current driving path and another driving path.

[0072] ΔM=F×tanθ×R (3)

[0073] In the above formula (3), ΔM represents the adjustment amount of the torque output by the electric motor of the electric drive system to the wheel; F represents the magnitude of the driving force provided by the electric motor of the electric drive system to the wheel from the starting point to the end point of the path; R represents the wheel radius of the electric vehicle.

[0074] The adjustment amount ΔM of the torque output to the wheels by the electric motor of the electric drive system is controlled to adjust the torque output to the wheels by the electric motor of the electric drive system, and the adjustment direction is the same as the turning direction of the front wheel of the electric vehicle, so that the electric vehicle switches to another driving path.

[0075] The beneficial effects of the above technical solution are as follows: Using the above formula (1), the path direction deviation between the current driving path and the other driving path is obtained based on the vector representation of the current driving path of the electric vehicle and the vector representation of the other driving path. Then, the shortest deviation between the current driving path and the other driving path can be quantified using the path direction deviation. Finally, the optimal path for switching the electric vehicle to the other driving path can be found based on the shortest deviation. Using the above formula (2), the steering angle of the front wheels of the electric vehicle is adjusted based on the path direction deviation between the current driving path and the other driving path. Then, the front wheels of the electric vehicle are intelligently adjusted based on different current path direction deviations. The turning angle is adjusted to ensure that when the directional deviation is large, the angle can be adjusted in time to allow the electric vehicle to switch to another driving path. When the directional deviation is small, it prevents the electric vehicle from deviating from the other driving path during the overall switching process due to providing too large a turning angle, so as to achieve the purpose of overall reliability. Using the above formula (3), the torque output of the electric motor to the wheels of the electric drive system is adjusted according to the path directional deviation between the current driving path and the other driving path, thereby ensuring that the electric vehicle increases the appropriate torque without changing the current speed so that the electric vehicle switches to another driving path, ensuring the working efficiency of the electric vehicle and enhancing the user experience of the electric vehicle.

[0076] Preferably, in step S3, if another driving path exists, the path deviation between the current driving path of the electric vehicle and the other driving path is determined, and based on the path deviation, the electric drive system's motor is instructed to adjust the torque output to the wheels. This specifically includes:

[0077] If another driving path exists, the path direction deviation between the current driving path of the electric vehicle and the other driving path is determined. Based on the path direction deviation, the magnitude and direction of the torque output by the electric motor of the electric drive system to the wheels and the steering angle of the front wheels of the electric vehicle are adjusted, so that the overall driving of the electric vehicle switches to the other driving path.

[0078] The beneficial effects of the above technical solution are as follows: Switching an electric vehicle from its current driving path to another requires changing the steering angle of the front wheels and the torque output by the motor. The magnitude of the path direction deviation between the current and other driving paths directly determines the steering angle of the front wheels and the torque output by the motor. By adjusting the magnitude and direction of the torque output by the motor and the steering angle of the front wheels based on this path direction deviation, the electric vehicle can quickly and accurately switch from its current driving path to another.

[0079] Preferably, in step S4, if there is no other driving path, the analysis of the three-dimensional dimensions of the obstacle specifically includes:

[0080] If no alternative driving path exists, the height and maximum width of the obstacle are identified from the 3D road image.

[0081] The beneficial effects of the above technical solution are as follows: when it is determined that there is no alternative driving path to the left or right of an obstacle that allows the electric vehicle to completely avoid it, the electric vehicle can only directly run over the obstacle. The greater the height and width of the obstacle, the greater the probability of the electric vehicle overturning when running over it. By identifying the height and maximum width of the obstacle from the three-dimensional road image, it is easier to adjust the magnitude and direction of the torque output from the motor to the wheels according to the size of the obstacle, thereby ensuring that the electric vehicle smoothly runs over the obstacle.

[0082] Preferably, in step S4, instructing the electric drive system's motor to adjust the torque output to the wheels based on the three-dimensional dimensions, so that the electric vehicle's wheels can smoothly roll over obstacles, specifically includes:

[0083] If the height of the obstacle is greater than or equal to the threshold height threshold and the maximum width is greater than or equal to the threshold width threshold, the electric drive system's motor is instructed to reduce the torque output to the wheels; otherwise, the electric drive system's motor is instructed to maintain the current torque output to the wheels, thereby enabling the electric vehicle's wheels to smoothly roll over the obstacle.

[0084] The beneficial effects of the above technical solution are as follows: when the height value of the obstacle is greater than or equal to the threshold height threshold and the maximum width value is greater than or equal to the threshold width threshold, it indicates that the volume of the obstacle is too large. If the electric vehicle continues its current driving state and directly runs over the obstacle, it is easy to roll over. At this time, the electric drive system motor is instructed to reduce the torque output to the wheels, which can ensure that the electric vehicle smoothly runs over the obstacle and effectively avoids rollover.

[0085] As can be seen from the above embodiments, the efficiency improvement method of the electric drive system collects and analyzes road surface images of the road ahead during the electric vehicle's driving process, thereby determining the existence of obstacles on the road ahead and whether there is any overlap between the electric vehicle's current driving path and the obstacles. Furthermore, by acquiring information on the lateral friction force between the electric vehicle's wheels and the road surface, whether there is another driving path ahead that allows the electric vehicle to completely avoid obstacles, and the three-dimensional dimensions of the obstacles, the method adaptively instructs the electric drive system's motor to adjust the torque output to the wheels. This enables the electric vehicle to adjust the motor's output torque according to the presence and location of obstacles during actual driving, thereby efficiently converting and utilizing the electric vehicle's battery energy, thus improving the stability of the electric vehicle's driving and saving the electric vehicle's battery energy.

[0086] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for improving the efficiency of an electric drive system, comprising the following steps: Step S1: Collect road surface images of the road ahead while the electric vehicle is driving, analyze the road surface images, and determine the existence information of obstacles on the road ahead; based on the obstacle existence information, determine whether there is an overlap between the current driving path of the electric vehicle and the obstacles; Step S2: If there is no overlap, obtain the lateral friction force information between the wheels of the electric vehicle and the road surface, and instruct the electric drive system motor to adjust the torque output to the wheels based on the lateral friction force information. Step S3: If there is an overlap, analyze the road image to determine if there is another driving path ahead that allows the electric vehicle to completely avoid the obstacle; if there is another driving path, determine the path deviation between the current driving path of the electric vehicle and the other driving path, and instruct the electric drive system's motor to adjust the torque output to the wheels based on the path deviation. In step S4, if there is no other driving path, the three-dimensional dimensions of the obstacle are analyzed, and based on the three-dimensional dimensions, the electric motor of the electric drive system is instructed to adjust the torque output to the wheels, so that the wheels of the electric vehicle can smoothly roll over the obstacle.

2. The method for improving the efficiency of an electric drive system as described in claim 1, characterized in that: In step S1, acquiring road surface images of the road ahead while the electric vehicle is driving, and analyzing the road surface images to determine the presence of obstacles on the road ahead specifically includes: The road surface ahead is captured by binocular cameras during the driving of an electric vehicle, thereby obtaining a binocular road surface image; based on the image parallax of the binocular road surface image, a three-dimensional road surface image corresponding to the road ahead is obtained. The location information of obstacles on the plane of the road surface is identified from the three-dimensional road image.

3. The method for improving the efficiency of an electric drive system as described in claim 2, characterized in that: In step S1, determining whether there is an overlap between the electric vehicle's current driving path and the obstacle based on the obstacle presence information specifically includes: Obtain the current centerline of the electric vehicle and determine the vertical distance between the obstacle and the straight line containing the centerline of the vehicle. If the vertical distance is less than or equal to half the width of the electric vehicle, it is determined that there is an overlap between the current driving path of the electric vehicle and the obstacle; otherwise, it is determined that there is no overlap between the current driving path of the electric vehicle and the obstacle.

4. The method for improving the efficiency of an electric drive system as described in claim 1, characterized in that: In step S2, if there is no overlap, the lateral friction force information between the electric vehicle's wheels and the road surface is obtained, and based on the lateral friction force information, the electric drive system's motor is instructed to adjust the torque output to the wheels. This specifically includes: If there is no overlap, the frictional force information between the wheel and the road surface during the driving process of the electric vehicle is obtained in the direction perpendicular to the wheel hub surface, and this is used as the lateral frictional force information. The lateral frictional force value corresponding to the lateral frictional force information is compared with a preset frictional force threshold. If the lateral frictional force value is less than or equal to the preset frictional force threshold, the electric drive system motor is instructed to maintain the current torque output to the wheel unchanged. If the lateral frictional force value is greater than or equal to the preset frictional force threshold, the electric drive system motor is instructed to increase the torque output to the wheel in the direction opposite to the lateral frictional force.

5. The method for improving the efficiency of an electric drive system as described in claim 2, characterized in that: In step S3, if there is overlap, the road surface image is analyzed to determine whether there is another driving path ahead that allows the electric vehicle to completely avoid the obstacle. Specifically, this includes: If there is overlap, the width of the free road surface corresponding to the left or right side of the obstacle is identified from the three-dimensional road surface image; The width of the free road surface corresponding to the left or right side of the obstacle is compared with the width of the electric vehicle body. If the width of the free road surface is greater than the width of the vehicle body, it is determined that there is another driving path on the left or right side of the obstacle that allows the electric vehicle to completely avoid the obstacle; otherwise, it is determined that there is no other driving path on the left or right side of the obstacle that allows the electric vehicle to completely avoid the obstacle.

6. The method for improving the efficiency of an electric drive system as described in claim 5, characterized in that: In step S3, if another driving path exists, the path deviation between the current driving path of the electric vehicle and the other driving path is determined, and based on the path deviation, the electric drive system's motor is instructed to adjust the torque output to the wheels. This specifically includes: If another driving path exists, the path direction deviation between the current driving path of the electric vehicle and the other driving path is determined, and the magnitude and direction of the torque output by the electric motor of the electric drive system to the wheels and the steering angle of the front wheels of the electric vehicle are adjusted according to the path direction deviation, so that the overall driving of the electric vehicle switches to the other driving path.

7. The method for improving the efficiency of an electric drive system as described in claim 6, characterized in that: In step S3, determining the path direction deviation between the current driving path of the electric vehicle and another driving path, and adjusting the magnitude and direction of the torque output by the electric motor to the wheels and the steering angle of the front wheels of the electric vehicle based on the path direction deviation, thereby switching the overall driving of the electric vehicle to another driving path, specifically includes: Step S301: Using the formula (1) below, based on the vector representation of the current driving path of the electric vehicle and the vector representation of another driving path, obtain the path direction deviation between the current driving path and the other driving path. In the above formula (1), L represents the path direction deviation between the current driving path of the electric vehicle and another driving path; (X e -x0,Y e -y0) represents the direction vector of the electric vehicle's current driving path from the starting point of the path to the current position of the electric vehicle; (X c -x0,Y c (x0, y0) represents the direction vector of another driving path from its starting point to the closest position on that path to the electric vehicle; (x0, y0) represents the coordinates of the starting point of the driving path; (X e ,Y e (X) represents the current position coordinates of the electric vehicle; c ,Y c ) represents the coordinates of the position closest to the electric vehicle on the other driving path; · represents the vector dot product operation; || represents the operation of calculating the vector magnitude; Step S302: Using formula (2) below, adjust the steering angle of the electric vehicle's front wheels based on the path direction deviation between the current driving path and another driving path. In formula (2) above, θ represents the steering angle of the front wheels of the electric vehicle; θ max This indicates the maximum steering angle within the controllable range of the front wheels of an electric vehicle; Step S303: Using the following formula (3), adjust the magnitude and direction of the torque output from the electric motor of the electric drive system to the wheels based on the path direction deviation between the current driving path and another driving path. ΔM=F×tanθ×R (3) In the above formula (3), ΔM represents the adjustment amount of the torque output by the electric motor of the electric drive system to the wheel; F represents the magnitude of the driving force provided by the electric motor of the electric drive system to the wheel from the starting point to the end point of the path; R represents the wheel radius of the electric vehicle. The adjustment amount ΔM of the torque output to the wheels by the electric motor of the electric drive system is controlled to adjust the torque output to the wheels by the electric motor of the electric drive system, and the adjustment direction is the same as the turning direction of the front wheel of the electric vehicle, so that the electric vehicle switches to another driving path.

8. The method for improving the efficiency of an electric drive system as described in claim 2, characterized in that: In step S4, if there is no other driving path, the analysis of the three-dimensional dimensions of the obstacle specifically includes: If no alternative driving path exists, the height and maximum width of the obstacle are identified from the three-dimensional road surface image.

9. The method for improving the efficiency of an electric drive system as described in claim 8, characterized in that: In step S4, based on the three-dimensional dimensions, instructing the electric drive system's motor to adjust the torque output to the wheels, thereby enabling the electric vehicle's wheels to smoothly roll over obstacles, specifically includes: If the height of the obstacle is greater than or equal to a threshold height threshold and the maximum width is greater than or equal to a threshold width threshold, the electric drive system's motor is instructed to reduce the torque output to the wheels; otherwise, the electric drive system's motor is instructed to maintain the current torque output to the wheels, thereby enabling the electric vehicle's wheels to smoothly roll over the obstacle.

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