Motor power difference dynamic iteration compensation distribution method based on double electric drive axles

Abstract

The invention discloses a motor power difference dynamic iteration compensation distribution method based on double electric drive axles. The method comprises the steps that the target temperature of a main drive motor and the target temperature of an auxiliary motor are obtained according to the current road condition; obtaining a corresponding first motor power difference and a corresponding second motor power difference based on the actually measured temperatures of the double motors and the corresponding target temperatures; combining the respective current power requests of the double motors with the corresponding motor power difference to obtain a corresponding first power initial value and a second power initial value; acquiring a second power deviation and a first power deviation by using a progressive mode; and determining a final power request of the dual motors based on the first motor power difference, the second motor power difference, the first power deviation, the first power initial value, the second power deviation and the second power initial value. Dynamic iteration compensation is performed on the power difference of the double motors based on the road condition and the motor temperature, an optimized power distribution result is obtained, the energy recovery rate can be remarkably improved, motor losses are reduced, the service life of a battery is prolonged, and the efficiency of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle drive technology, and in particular to a motor power difference dynamic iterative compensation distribution method based on a dual electric drive bridge. Background Art

[0002] With the increasing attention paid to environmental protection and sustainable development around the world, the new energy vehicle industry has ushered in opportunities for vigorous development. Among the many types of new energy vehicles, commercial vehicles, especially heavy trucks, have a more urgent need for energy conservation and emission reduction due to their long operating mileage and high energy consumption. Traditional fuel heavy trucks are facing severe environmental regulations and energy crisis challenges, while new energy heavy trucks have gradually become the focus of industry development with their advantages of zero or low emissions.

[0003] In order to meet the power performance requirements of new energy heavy-duty trucks, dual electric drive axle technology came into being. Compared with the single motor drive system, the dual electric drive axle can provide greater driving force and better adapt to the heavy-load transportation needs of heavy-duty trucks. At the same time, it shows better performance when accelerating, climbing, and coping with complex road conditions. However, the efficient operation of the dual electric drive axle system faces a key problem, that is, how to reasonably distribute the torque between the two electric drive axles, which is directly related to the vehicle's power, energy efficiency, and driving stability.

[0004] In the previous development of new energy vehicles with dual electric drive axles, there were many deficiencies in torque distribution technology. Some simple fixed-ratio distribution methods cannot be dynamically adjusted according to the actual driving conditions of the vehicle, resulting in the vehicle's performance not being optimal under different conditions. For example, when the vehicle starts and climbs a slope at low speed, a large torque is required to overcome inertia and gravity, but the fixed-ratio distribution may not be able to concentrate enough torque on the required electric drive axle, thus affecting the vehicle's starting acceleration and climbing ability, and may even cause the motor to overload or operate inefficiently.

[0005] In addition, some vehicles use a torque distribution strategy based on a single sensor signal (such as vehicle speed or accelerator pedal opening). Although this method can achieve dynamic adjustment to a certain extent, it cannot fully and accurately reflect the actual operating status of the vehicle due to limited consideration of factors. For example, under complex road conditions, such as when the vehicle is driving on a curve, slippery road surface, or in frequent start-stop urban traffic, torque distribution based only on vehicle speed or throttle signals cannot fully consider factors such as wheel adhesion, vehicle yaw stability, and energy recovery requirements, which can easily cause vehicle control difficulties, energy waste, and even safety hazards. Summary of the invention

[0006] In view of the above, the present invention aims to provide a method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges to solve the technical problems mentioned above.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The present invention provides a motor power difference dynamic iterative compensation allocation method based on dual electric drive bridges, which includes:

[0009] According to the current road conditions, the target temperatures of the main drive motor and the auxiliary motor are obtained respectively;

[0010] Based on the measured temperatures of the main drive motor and the auxiliary motor and the corresponding target temperatures, obtaining a first motor power difference of the main drive motor and a second motor power difference of the auxiliary motor;

[0011] Respectively obtain the current power requests of the main drive motor and the auxiliary motor, and combine them with the corresponding motor power differences to obtain a first initial power value of the main drive motor and a second initial power value of the auxiliary motor;

[0012] Obtaining a second power deviation and a first power deviation using a current power request of the auxiliary motor, a second power initial value, and a first power initial value;

[0013] Based on the first motor power difference, the second motor power difference, the first power deviation, and the first power initial value, a first final power request for the main drive motor is determined; based on the first motor power difference, the second motor power, the first power deviation, the second power deviation, and the second power initial value, a second final power request for the auxiliary motor is determined.

[0014] In at least one possible implementation method, the method for determining the first final power request includes: combining the first motor power difference and the second motor power difference with a preset adjustment coefficient and multiplying them with the first power deviation, and then summing them with the first power initial value to obtain the first final power request.

[0015] In at least one possible implementation method, the method for determining the second final power request includes: combining the first motor power difference and the second motor power difference with a preset adjustment coefficient and multiplying them with the first power deviation, then subtracting them from the first power deviation, and then summing them with the second power deviation to obtain a third power deviation; combining the third power deviation with the second power initial value to obtain the second final power request.

[0016] In at least one possible implementation manner, obtaining the second power deviation and the first power deviation includes:

[0017] Subtracting the current power request of the auxiliary motor from the second initial power value to obtain a second power deviation;

[0018] The first power deviation is obtained by subtracting the first power initial value from the second power deviation.

[0019] In at least one possible implementation, the current power request is obtained by respectively obtaining the current power requests of the main drive motor and the auxiliary motor by querying a pre-calibrated mapping table according to the current throttle opening and vehicle speed.

[0020] In at least one possible implementation, the distribution control method further includes: constructing a road condition identification mechanism in advance based on real-time slope, throttle opening, vehicle speed, and mileage information, wherein the road condition includes at least any one of the following: highway, climbing, downhill, and expressway.

[0021] Compared with the prior art, the main design concept of the present invention is to obtain the target temperature of the main drive motor and the auxiliary motor respectively according to the current road conditions; obtain the first motor power difference of the main drive motor and the second motor power difference of the auxiliary motor based on the measured temperature of the main drive motor and the auxiliary motor and the corresponding target temperature; obtain the current power request of the main drive motor and the auxiliary motor respectively, and combine with the corresponding motor power difference to obtain the corresponding first power initial value and second power initial value; obtain the second power deviation and the first power deviation using the current power request, the second power initial value and the first power initial value of the auxiliary motor; determine the final power request of the main drive motor and the auxiliary motor respectively based on the first motor power difference, the second motor power difference, the first power deviation, the first power initial value, the second power deviation and the second power initial value. The present invention dynamically iteratively compensates the power difference of the dual motors based on the road conditions and the motor temperature, and obtains the optimized final power allocation result, which can significantly improve the energy recovery efficiency, reduce motor loss, and improve battery life and efficiency.

[0022] In summary, the technical solution of the present invention can have at least the following four advantages:

[0023] (1) Optimizing torque distribution: In the dual electric drive axle system, by dynamically iterating and compensating for the power difference between the dual motors, the torque of the two motors can be more accurately distributed according to the vehicle's real-time driving conditions, such as acceleration, climbing, turning, etc. For example, during acceleration, if it is found that the output power difference between the front and rear motors affects the acceleration performance of the vehicle, dynamic iterative compensation can be used to make timely adjustments to make the torque distribution more reasonable, thereby improving the vehicle's acceleration capability and overall power performance, reducing acceleration time, and improving transportation efficiency.

[0024] (2) Improve energy recovery efficiency: Under braking and deceleration conditions, reasonable power difference compensation can ensure that both motors can operate in the optimal efficiency range during the energy recovery process. Through dynamic adjustment, the energy recovery system can better adapt to different braking intensities and vehicle speed changes, improve the efficiency of braking energy recovery, convert more vehicle kinetic energy into electrical energy for storage, increase the cruising range, and also reduce energy waste and improve energy utilization efficiency.

[0025] (3) Reduce motor loss: If the power difference between the two motors is large and is not compensated in time, one motor may be in a high-load or low-efficiency working state for a long time, thereby increasing the motor's loss and energy consumption. Dynamic iterative compensation can make the workload of the two motors more balanced, avoid additional energy loss due to excessive use or inefficient operation of the motor, extend the motor's service life, and reduce the cost of motor maintenance and replacement.

[0026] (4) Improving battery life and efficiency: Power difference compensation helps optimize the battery charging and discharging process. During energy recovery, it avoids overcharging or over-discharging of the battery due to power difference, reduces irreversible capacity loss of the battery, and extends the battery cycle life. At the same time, stable power input and output also help improve the battery charging and discharging efficiency, reduce the battery's energy consumption cost, and further improve the vehicle's economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0028] Figure 1 A schematic diagram of a method for dynamic iterative compensation and allocation of motor power differences based on dual electric drive bridges provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0030] The present invention proposes an embodiment of a motor power difference dynamic iterative compensation allocation method based on a dual electric drive bridge. Specifically, Figure 1 shown, including:

[0031] Step S1, obtaining target temperatures of the main drive motor (motor 1) and the auxiliary motor (motor 2) respectively according to the current road conditions;

[0032] In actual operation, the correspondence between the road condition and the motor target temperature can be calibrated through experiments to construct a first mapping table, and then the target temperature values ​​corresponding to the dual motors can be obtained by looking up the table through the signs that characterize the current driving road conditions.

[0033] It can be added here that the allocation control method also includes:

[0034] A road condition recognition mechanism is constructed in advance based on real-time slope, throttle opening, vehicle speed, and mileage information, wherein the road condition includes at least one of the following: highway, climbing, downhill, and expressway. Therefore, the following road condition signs can be used to obtain examples:

[0035] In a given driving time / mileage cycle, if the vehicle speed is higher than 80km / h, it can be identified as a highway;

[0036] Detect vehicle speed changes and the average speed is less than 80km / h, and there are extremely low speeds or zero speeds, which can be identified as a main trunk road;

[0037] Also, by combining the mileage change with the slope change, it can be identified as uphill or downhill.

[0038] Step S2, obtaining a first motor power difference of the main drive motor and a second motor power difference of the auxiliary motor based on the measured temperatures of the main drive motor and the auxiliary motor and the corresponding target temperatures;

[0039] Similarly, the correspondence between the actual measured temperature of the motor and the target temperature of the motor can be calibrated through experiments, and the motor power difference can be represented by the relationship between the two. A second mapping table can be constructed, and then the motor power difference corresponding to the dual motors can be obtained by inputting the actual measured temperature and the target temperature through table lookup.

[0040] Step S3, respectively obtaining the current power requests of the main drive motor and the auxiliary motor, and combining them with the corresponding motor power differences to obtain a first initial power value of the main drive motor and a second initial power value of the auxiliary motor;

[0041] Specifically, it can be expressed as: main drive motor power request+first motor power difference=first power initial value; auxiliary motor power request+second motor power difference=second power initial value.

[0042] The power request may be obtained by looking up a table (understandably, a third MAP table is pre-calibrated) according to the current throttle opening and vehicle speed to obtain the current power requests of the main drive motor and the auxiliary motor respectively.

[0043] Step S4, obtaining a second power deviation and a first power deviation by using the current power request of the auxiliary motor, the second power initial value and the first power initial value;

[0044] The following progressive approach can be used to implement this process:

[0045] Subtracting the current power request of the auxiliary motor from the second initial power value to obtain a second power deviation;

[0046] The first power deviation is obtained by subtracting the first power initial value from the second power deviation.

[0047] Step S5, determining a first final power request of the main drive motor based on the first motor power difference, the second motor power difference, the first power deviation, and the first power initial value;

[0048] A second final power request for the auxiliary electric machine is determined based on the first electric machine power difference, the second electric machine power, the first power offset, the second power offset, and the second initial power value.

[0049] Finally, after the dynamic iteration and filtering differences in the above links, the dual motors are respectively allocated to the final power requests. The allocation methods for the two motors are as follows:

[0050] (1) obtaining an adjustment coefficient by obtaining a power difference between the first motor and the second motor, multiplying the adjustment coefficient by the first power deviation, and then combining (which may be addition) the first power initial value to obtain a first final power request;

[0051] (2) The power difference between the first motor and the power difference between the second motor obtain an adjustment coefficient, which is multiplied by the first power deviation, and then subtracted from the first power deviation (which can be the first power deviation minus the above product), and then combined (which can be added) with the second power deviation to obtain a third power deviation; the third power deviation is combined (which can be added) with the second power initial value to obtain a second final power request.

[0052] In summary, the main design concept of the present invention is to obtain the target temperature of the main drive motor and the auxiliary motor respectively according to the current road conditions; based on the measured temperature of the main drive motor and the auxiliary motor and the corresponding target temperature, obtain the first motor power difference of the main drive motor and the second motor power difference of the auxiliary motor; obtain the current power request of the main drive motor and the auxiliary motor respectively, and combine with the corresponding motor power difference to obtain the corresponding first power initial value and second power initial value; use the current power request, the second power initial value and the first power initial value of the auxiliary motor to obtain the second power deviation and the first power deviation; based on the first motor power difference, the second motor power difference, the first power deviation, the first power initial value, the second power deviation, and the second power initial value, respectively determine the final power request of the main drive motor and the auxiliary motor. The present invention dynamically iteratively compensates for the power difference of the dual motors based on the road conditions and the motor temperature, and obtains the optimized final power distribution result, which can significantly improve the energy recovery efficiency, reduce motor loss, and improve battery life and efficiency.

[0053] If the expressions expressing orientation are mentioned in the embodiments of the present invention, they are relative concepts based on the embodiments. In addition, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b, c can be single or multiple.

[0054] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the present invention is not limited to the scope of implementation shown in the drawings, and all changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification and drawings, should be within the protection scope of the present invention.

Claims

1. A method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges, characterized in that: include: According to the current road conditions, the target temperatures of the main drive motor and the auxiliary motor are obtained respectively; Based on the measured temperatures of the main drive motor and the auxiliary motor and the corresponding target temperatures, obtaining a first motor power difference of the main drive motor and a second motor power difference of the auxiliary motor; Respectively obtain the current power requests of the main drive motor and the auxiliary motor, and combine them with the corresponding motor power differences to obtain a first initial power value of the main drive motor and a second initial power value of the auxiliary motor; Obtaining a second power deviation and a first power deviation using a current power request of the auxiliary motor, a second power initial value, and a first power initial value; Based on the first motor power difference, the second motor power difference, the first power deviation, and the first power initial value, a first final power request for the main drive motor is determined; based on the first motor power difference, the second motor power, the first power deviation, the second power deviation, and the second power initial value, a second final power request for the auxiliary motor is determined.

2. The method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges according to claim 1, characterized in that: The first final power request is determined by combining the first motor power difference and the second motor power difference with a preset adjustment coefficient, multiplying the first power deviation, and then summing the result with the first power initial value to obtain the first final power request.

3. The method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges according to claim 1, characterized in that: The method for determining the second final power request includes: multiplying the first motor power difference and the second motor power difference by the preset adjustment coefficient and then subtracting them from the first power deviation, and then summing them with the second power deviation to obtain a third power deviation; combining the third power deviation with the second power initial value to obtain the second final power request.

4. The method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges according to claim 1, characterized in that: The obtaining of the second power deviation and the first power deviation comprises: Subtracting the current power request of the auxiliary motor from the second initial power value to obtain a second power deviation; The first power deviation is obtained by subtracting the first power initial value from the second power deviation.

5. The method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges according to claim 1, characterized in that: The current power request is obtained by respectively obtaining the current power requests of the main drive motor and the auxiliary motor by querying a pre-calibrated mapping table according to the current throttle opening and vehicle speed.

6. The method for dynamic iterative compensation and allocation of motor power difference based on dual electric drive bridges according to any one of claims 1 to 5, characterized in that: The distribution control method also includes: constructing a road condition identification mechanism in advance according to real-time slope, throttle opening, vehicle speed, and mileage information, wherein the road condition includes at least any one of the following: highway, climbing, downhill, and expressway.

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