Three-motor driving energy management method and device and vehicle driving system

Abstract

The embodiment of the invention provides a three-motor driving energy management method and device and a vehicle driving system. Relates to the technical field of electric vehicle energy management. The method comprises the following steps: acquiring a current driving state, a current driving mode and driving demand parameters in the current driving state of a target vehicle; according to the driving demand parameters, a working efficiency diagram of the target motor in the current driving mode is adopted, and multiple sets of associated rotating speed torque points meeting preset matching conditions with the driving demand parameters are obtained; according to the current driving state, a target rotating speed torque point is determined from the multiple sets of associated rotating speed torque points; and performing energy distribution on the target motor according to the target rotating speed torque point. Therefore, the energy consumption can be effectively controlled, the driving range of the vehicle is increased, the use range of the vehicle is widened, and the user experience is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle energy management, and more specifically, to a three-motor driven energy management method, device and vehicle drive system. Background Art

[0002] The energy of electric vehicles mainly comes from power batteries, and the energy consumption mainly comes from the consumption of electricity. Under the same power demand, multiple driving modes will lead to different motor utilization rates. The core goal of driving mode switching for electric vehicles is to maximize the efficiency of the motor and save electricity.

[0003] Most of the existing distributed drive technologies analyze the entire vehicle based on the Ackerman steering model and the body stability system, focusing mainly on the vehicle's handling stability and safety, but without detailed analysis of motor torque control, speed control, and energy recovery functions under multiple working conditions. As a result, the control logic of the power domain cannot dynamically adjust the working state of the motor according to the real-time working conditions, thereby failing to achieve effective control of energy consumption, which seriously affects the vehicle's driving range and scope of use, and reduces the user experience. Summary of the invention

[0004] In view of this, the purpose of this application is to provide a three-motor driven energy management method, device and vehicle drive system to achieve effective control of energy consumption, increase the vehicle's driving range and usage range, and improve user experience.

[0005] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides an energy management method for a three-motor drive, comprising:

[0007] Acquire the current driving state, current driving mode and driving demand parameters under the current driving state of the target vehicle;

[0008] According to the drive demand parameter, a working efficiency diagram of the target motor in the current drive mode is used to obtain a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter;

[0009] Determining a target speed torque point from the plurality of sets of associated speed torque points according to the current driving state;

[0010] Energy is distributed to the target motor according to the target speed torque point.

[0011] Optionally, determining the target speed torque point from the plurality of groups of associated speed torque points according to the current driving state includes:

[0012] If the current driving state is a forward state, respectively obtaining the working efficiencies corresponding to the plurality of groups of associated speed torque points from the working efficiency diagram of the target motor;

[0013] Calculating a plurality of energy consumption parameters of the target motor at the plurality of sets of associated speed-torque points according to the speeds, torques and corresponding working efficiencies of the plurality of sets of associated speed-torque points;

[0014] According to the multiple energy consumption parameters, a speed-torque point with the minimum energy consumption parameter is determined from the multiple groups of associated speed-torque points as the target speed-torque point.

[0015] Optionally, the drive demand parameter includes: the current speed of the target motor; and according to the drive demand parameter, using the working efficiency diagram of the target motor under the current drive mode, obtaining a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter, including:

[0016] According to the current speed, the working efficiency diagram of the target motor is used to determine multiple associated speeds whose speed deviation from the current speed is within a preset speed deviation range and the torques corresponding to the multiple associated speeds, each group of associated speed-torque points includes: an associated speed and a corresponding torque.

[0017] Optionally, the driving demand parameter also includes: the opening and closing degree of the accelerator pedal and the current vehicle speed;

[0018] Before distributing energy to the target motor according to the target speed torque point, the method further includes:

[0019] Calculating a target acceleration torque corresponding to the target motor according to the opening and closing degree of the accelerator pedal and the current vehicle speed;

[0020] The energy distribution to the target motor according to the target speed torque point includes:

[0021] If the torque at the target speed torque point is greater than or equal to the target acceleration torque, allocating the speed and torque at the target speed torque point to the target motor;

[0022] If the torque of the target speed torque point is less than the target acceleration torque, another speed torque point whose torque is greater than or equal to the target speed torque is determined from the multiple groups of associated speed torque points, and the torque of the target speed torque point is first allocated to the target motor, and when the speed of the target motor reaches the speed of the another speed torque, the torque of the another speed torque point is allocated to the target motor.

[0023] Optionally, determining a target rotational speed - torque point from the multiple sets of associated rotational speed - torque points according to the current driving state includes:

[0024] If the current driving state is a braking state, obtain the working efficiencies corresponding to the multiple sets of associated rotational speed - torque points from the working efficiency map of the target motor respectively;

[0025] According to the rotational speeds, torques and corresponding working efficiencies of the multiple sets of associated rotational speed - torque points, calculate multiple energy recovery parameters of the target motor at the multiple sets of associated rotational speed - torque points respectively;

[0026] According to the multiple energy recovery parameters, determine the rotational speed - torque point with the maximum energy recovery parameter from the multiple sets of associated rotational speed - torque points as the target rotational speed - torque point.

[0027] Optionally, the driving demand parameters include: the opening degree of the brake pedal and the current vehicle speed, or a preset energy recovery level;

[0028] Obtaining multiple sets of associated rotational speed - torque points that meet a preset matching condition with the driving demand parameters by using the working efficiency map of the target motor in the current driving mode according to the driving demand parameters includes:

[0029] Determine a target reverse torque according to the opening degree of the brake pedal and the current vehicle speed, or the preset energy recovery level;

[0030] According to the target reverse torque, determine multiple associated rotational speeds within a preset torque deviation range from the torque of the target reverse torque in the working efficiency map of the target motor and the torques corresponding to the multiple associated rotational speeds. Each set of associated rotational speed - torque points includes: one associated rotational speed and the corresponding torque.

[0031] Optionally, performing energy distribution on the target motor according to the target rotational speed - torque point includes:

[0032] Allocate both the rotational speed and torque of the target rotational speed - torque point to the target motor.

[0033] Optionally, if the target motor includes: two rear - drive motors;

[0034] Performing energy distribution on the target motor according to the target rotational speed - torque point includes:

[0035] Allocate the same target rotational speed - torque to the two rear - drive motors.

[0036] In a second aspect, an energy management device for a three - motor drive provided by an embodiment of the present application includes:

[0037] A first acquisition module, used to acquire the current driving state, the current driving mode and the driving demand parameters under the current driving state of the target vehicle;

[0038] A second acquisition module is used to acquire, according to the drive demand parameter, a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter by using a working efficiency diagram of the target motor in the current drive mode;

[0039] A determination module, configured to determine a target speed torque point from the plurality of sets of associated speed torque points according to the current driving state;

[0040] The allocation module is used to allocate energy to the target motor according to the target speed torque point.

[0041] In a third aspect, an embodiment of the present application provides a vehicle drive system, including: a vehicle controller, a front drive motor controller, a front drive motor, a front drive reducer, a differential, two rear drive motor controllers, two rear drive motors, and two rear drive reducers;

[0042] The front drive motor is connected to the differential of the front wheel axle through the front drive reducer; the two rear drive motors drive the rear drive reducers connected to the two rear wheels respectively;

[0043] The front drive motor controller is connected to the front drive motor, and the two rear drive motor controllers are respectively connected to the two rear drive motors;

[0044] The vehicle controller is communicatively connected to the front-drive motor controller and the two rear-drive motor controllers, and the vehicle controller is used to execute the method described in the first aspect above.

[0045] Compared with the prior art, this application has the following beneficial effects:

[0046] The embodiment of the present application proposes a three-motor driven energy management method, device and vehicle drive system. It relates to the field of electric vehicle energy management technology. The current driving state, current driving mode and driving demand parameters under the current driving state of the target vehicle are obtained, so that by obtaining the above information, the vehicle controller can accurately adjust the working state of the front drive motor and the rear drive motor according to the actual needs of the target vehicle; according to the driving demand parameters, the working efficiency diagram of the target motor under the current driving mode is used to obtain multiple groups of associated speed torque points that meet the preset matching conditions with the driving demand parameters, so as to find the speed torque points that match the driving demand parameters through the working efficiency diagram, so that the target motor can work in a state close to the optimal efficiency. This can reduce energy loss, reduce the power consumption of the target vehicle battery, and extend the cruising range of the target vehicle. At the same time, according to the driving requirements of the target vehicle, a low-speed, low-torque operating point with high efficiency of the target motor can be selected to avoid the target motor from operating in a high-energy-consuming working area; according to the current driving state, the target speed torque point is determined from multiple sets of associated speed torque points; according to the target speed torque point, the energy of the target motor is distributed to select a matching target speed torque point according to the actual driving state of the target vehicle, so that the power output by the target motor can just meet the needs of the target vehicle, thereby enabling the target vehicle to obtain the best power performance, avoiding the situation of excess or insufficient power, and improving the driving experience. At the same time, by giving priority to the speed torque point with high efficiency of the target motor, the rational use and optimal management of energy are achieved. Under different driving conditions, the target motor can work in a more energy-saving state, reducing the power consumption of the battery, thereby extending the cruising range of the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of the structure of a vehicle drive system provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of the structure of a vehicle controller provided in an embodiment of the present application;

[0051] Figure 4 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present applicationFigure 1 ;

[0052] Figure 5 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 2 ;

[0053] Figure 6 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 3 ;

[0054] Figure 7 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 4 ;

[0055] Figure 8 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 5 ;

[0056] Figure 9 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 6 ;

[0057] Figure 10 A schematic diagram of the structure of a three-motor driven energy management device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0059] Figure 1 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. Figure 1 As shown, the vehicle 200 may include: a vehicle driving system 100 disposed inside the vehicle 200 .

[0060] Among them, the vehicle 200 can be a new energy vehicle.

[0061] The vehicle provided by the present application can reasonably plan the vehicle space by arranging the vehicle drive system inside the vehicle, avoiding the extra space occupied by the external drive system. The vehicle drive system is integrated inside the vehicle, making the connection and cooperation between the various components of the vehicle closer, simplifying the overall vehicle architecture. This not only reduces the complexity of vehicle assembly, but also reduces the exposure of external lines and components, reduces the probability of failure due to external factors, and improves the reliability of the vehicle.

[0062] Furthermore, the present application provides, for example, a vehicle driving system 100, Figure 2This is a schematic diagram of the structure of a vehicle drive system provided in an embodiment of the present application. Figure 2 As shown, the vehicle drive system 100 may include: a vehicle controller 110, a front drive motor controller 120, a front drive motor 130, a front drive reducer 140, a differential 150, two rear drive motor controllers 160, two rear drive motors 170 and two rear drive reducers 180.

[0063] Among them, the front drive motor 130 is driven and connected to the differential 150 set on the front wheel axle through the front drive reducer 140 to ensure that the power of the front drive motor 130 can be effectively transmitted to the front wheel axle to drive the vehicle forward, and the power is reasonably distributed to the left and right front wheels through the differential 150, so that the vehicle can travel stably; the two rear drive motors 170 respectively drive the rear drive reducers 180 connected to the two rear wheels, so that the torque output by the rear drive motor 170 is reasonably distributed and amplified through the rear drive reducers 180 according to the driving requirements of the vehicle, so as to meet the requirements of the vehicle for the torque and speed of the rear wheels under different road conditions (such as acceleration, climbing, etc.); the front drive motor controller 120 is connected to the front drive motor 130, and the two rear drive motor controllers 160 are respectively connected to the two rear drive motors 170 to adjust the operating parameters of each motor in real time and accurately; the vehicle controller 110 is communicatively connected to the front drive motor controller 120 and the two rear drive motor controllers 160 to collect feedback information from each motor controller and fully grasp the forward state of the vehicle motor.

[0064] The vehicle controller 110 is used to execute the energy management method of the three-motor drive. The vehicle controller 110 is a core control component in an electric vehicle or a hybrid electric vehicle, and can be represented by a VCU (Vehicle Control Unit).

[0065] The two rear drive motors 170 may include a left rear drive motor 171 and a right rear drive motor 172. The corresponding two rear drive motor controllers 160 may include a left rear drive motor controller 161 and a right rear drive motor controller 162; the corresponding two rear drive reducers 180 may include a left rear drive reducer 181 and a right rear drive reducer 182.

[0066] The differential 150 is used to adjust the speed difference between the left and right wheels to ensure that the left and right wheel speeds are equal, reduce wheel wear, and make the vehicle steering flexible and stable.

[0067] The two rear-drive reducers 180 are used to convert the rotation speed of each rear-drive motor into a wheel-end rotation speed through the gear ratio of each rear-drive reducer, and at the same time increase the torque of each rear-drive motor.

[0068] It should be noted that in Figure 2In addition to the above structure, the vehicle drive system 100 may also include: front wheel Hall wheel speed sensor and electric power steering system (EPS, Electronic Power Steering), etc. In addition, it should be emphasized that the vehicle drive system 100 provided in this application is not limited to the listed configurations, and subsequent expansions and modifications are within the scope of protection of this application. The vehicle drive system 100 configuration can not only accurately measure the front wheel speed and provide key data for the vehicle control system, but also significantly improve the steering control experience and safety during driving by relying on the electric power steering system.

[0069] The vehicle drive system provided by the present application can be composed of a vehicle controller, a front drive motor controller, a front drive motor, a front drive reducer, a differential, two rear drive motor controllers, two rear drive motors and two rear drive reducers; wherein the front drive motor is connected to the differential of the front wheel axle through the front drive reducer drive; the two rear drive motors drive the rear drive reducers connected to the two rear wheels respectively; the front drive motor controller is connected to the front drive motor to convert the high speed and low torque of the front drive motor into a low speed and high torque suitable for the wheels to meet the high torque requirements when the vehicle starts, accelerates and climbs; the two rear drive motor controllers are respectively connected to the two rear drive motors to achieve independent drive of the two rear wheels of the vehicle; the vehicle controller communicates with the front drive motor controller and the two rear drive motor controllers to monitor the forward state of each motor in real time, including speed, torque, temperature and other parameters; the vehicle controller is used for the energy management method of three motor drive. Therefore, the vehicle drive system provided by the present application can maintain the basic driving function of the vehicle, improve the reliability and safety of the system, and reduce the risk of vehicle stopping due to failure.

[0070] Optionally, the present application also provides a vehicle controller 110, Figure 3 This is a schematic diagram of the structure of a vehicle controller provided in an embodiment of the present application. Figure 3 As shown, the vehicle controller 110 may include: a processor 111 and a memory 112 .

[0071] The memory 112 stores machine executable instructions that can be executed by the processor 111, that is, when the vehicle controller 110 is running, the above machine readable instructions are executed, and the processor 111 communicates with the memory 112 via a bus. The processor 111 can execute the machine executable instructions to implement the energy management method of the three-motor drive.

[0072] Among them, the memory 112, the processor 111 and the bus components are directly or indirectly electrically connected to each other to realize data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The mobile storage device includes at least one software function module that can be stored in the memory 112 in the form of software or firmware or solidified in the operating system (OS) of the electronic device. The processor 111 is used to execute the executable modules stored in the memory 112, such as the software function modules and computer programs included in the energy management method of the three-motor drive of the mobile storage medium.

[0073] Among them, the memory 112 can be, but is not limited to, random access memory (Random Access Memory, RAM), read only memory (Read Only Memory, ROM), programmable read-only memory (Programmable Read-Only Memory, PROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable read-only memory (Electric Erasable Programmable Read-Only Memory, EEPROM), etc.

[0074] The energy management method for three-motor drive provided in the embodiment of the present application may be executed by a processor in the vehicle controller 110. The energy management method for three-motor drive provided in the embodiment of the present application is further explained as follows: Figure 4 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 1 .like Figure 4 As shown, the method may include:

[0075] S301, obtaining a current driving state, a current driving mode, and driving demand parameters under the current driving state of a target vehicle.

[0076] In one possible implementation, the driving state of the target vehicle itself is determined by the relevant data transmitted by various sensors installed on the target vehicle. For example, the wheel speed can be measured by the front wheel Hall wheel speed sensor, and the speed of the target vehicle can be calculated based on this, and then the current driving state of the target vehicle is obtained according to the speed of the target vehicle. For example, the current driving state of the target vehicle can be a braking state (or a sliding state), or a forward state, wherein the forward state includes an accelerated driving state, a uniform speed driving state, or a decelerated driving (non-braking deceleration) state, etc.

[0077] Since the vehicle controller is communicatively connected to the front drive motor controller and the two rear drive motor controllers, the current driving mode of the target vehicle can be determined based on the data obtained by the vehicle controller. Among them, if the current driving mode is the first driving mode (front-wheel drive mode), the target motor is the front drive motor; if the current driving mode is the second driving mode (dual-motor rear-wheel drive mode), the target motors include: two rear-wheel drive motors; if the current driving mode is the third driving mode (four-wheel drive mode), the target motors include: the front drive motor and two rear-wheel drive motors.

[0078] It should be noted that in practical applications, the current driving mode of the target vehicle can be switched according to the mode switch knob set inside the vehicle, and then the vehicle controller receives the output signal of the mode switch knob and determines which driving mode the target vehicle is in according to this output signal.

[0079] According to the current driving state of the target vehicle (such as forward state, braking state, coasting state, etc.) and the current driving mode, determine the driving demand parameters of the target vehicle. For example, when the target vehicle is in a climbing state and requires a large driving force, the vehicle controller will calculate parameters such as the required motor torque and power; if the target vehicle is cruising at high speed, to ensure driving stability and energy efficiency, the vehicle controller will determine appropriate motor speed and torque.

[0080] S302. According to the driving demand parameters, use the operating efficiency map of the target motor in the current driving mode to obtain multiple sets of associated speed-torque points that meet the preset matching conditions.

[0081] Among them, the operating efficiency map of the target motor describes the distribution of the operating efficiency of the target motor under different combinations of speed and torque.

[0082] In a possible implementation, according to the driving demand parameters of the target vehicle and the current driving mode, compare the data in the operating efficiency map of the target motor in the current driving mode with the driving demand parameters of the target vehicle to search for speed-torque points that meet the preset matching conditions on the operating efficiency map. There may be multiple sets of these points because at different combinations of speed and torque, the target motor may be able to meet the driving demand and have high efficiency.

[0083] S303. According to the current driving state, determine the target speed-torque point from multiple sets of associated speed-torque points.

[0084] In a possible implementation, according to the driving data corresponding to the current driving state of the target vehicle, comprehensively analyze these driving data and multiple sets of associated speed-torque points to obtain the applicability of each set of associated speed-torque points in the multiple sets of associated speed-torque points under the current driving state, and then determine the target speed-torque point under the current driving state.

[0085] It should be noted that determining the target speed torque point is a dynamic adjustment process, which is dynamically adjusted as the vehicle's driving state changes in real time. The vehicle controller can gradually optimize the selection criteria of the target speed torque point under different driving conditions to improve the overall performance and energy efficiency of the target vehicle.

[0086] S304: Distribute energy to the target motor according to the target speed torque point.

[0087] In one possible implementation, the target speed torque point is used to distribute energy to the target motor according to the target speed torque point required by the current driving state of the target vehicle to ensure that the target motor can operate at a speed torque point in a high efficiency range.

[0088] The energy management method of three-motor drive provided in this application obtains the current driving state, current driving mode and driving demand parameters of the target vehicle under the current driving state, so that by obtaining the above information, the vehicle controller can accurately adjust the working state of the front drive motor and the rear drive motor according to the actual needs of the target vehicle; according to the driving demand parameters, the working efficiency diagram of the target motor under the current driving mode is used to obtain multiple groups of associated speed torque points that meet the preset matching conditions with the driving demand parameters, so as to find the speed torque points that match the driving demand parameters through the working efficiency diagram, so that the target motor can work in a state close to the optimal efficiency. This can reduce energy loss, reduce the power consumption of the target vehicle battery, and extend the cruising range of the target vehicle. At the same time, according to the driving requirements of the target vehicle, a low-speed, low-torque operating point with high efficiency of the target motor can be selected to avoid the target motor from operating in a high-energy-consuming working area; according to the current driving state, the target speed torque point is determined from multiple sets of associated speed torque points; according to the target speed torque point, the energy of the target motor is distributed to select a matching target speed torque point according to the actual driving state of the target vehicle, so that the power output by the target motor can just meet the needs of the target vehicle, thereby enabling the target vehicle to obtain the best power performance, avoiding the situation of excess or insufficient power, and improving the driving experience. At the same time, by giving priority to the speed torque point with high efficiency of the target motor, the rational use and optimal management of energy are achieved. Under different driving conditions, the target motor can work in a more energy-saving state, reducing the power consumption of the battery, thereby extending the cruising range of the electric vehicle.

[0089] Figure 5 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 2 .like Figure 5 As shown, in the above method, determining the target speed torque point from a plurality of sets of associated speed torque points according to the current driving state may include:

[0090] S401: If the current driving state is the forward state, respectively obtain the working efficiencies corresponding to a plurality of groups of associated speed torque points from a working efficiency diagram of the target motor.

[0091] In one possible implementation, if the current driving state of the target vehicle is a forward state, then based on the corresponding driving data in the forward state, the working efficiencies corresponding to multiple groups of associated speed-torque points are respectively obtained from the working efficiency diagram of the target motor, so as to predict the energy consumption of the target vehicle under different driving conditions by observing the working efficiency change trends of the multiple groups of associated speed-torque points.

[0092] S402, calculating a plurality of energy consumption parameters of the target motor at the plurality of sets of associated speed-torque points according to the speeds, torques and corresponding working efficiencies of the plurality of sets of associated speed-torque points.

[0093] In a possible implementation, according to the speed, torque and corresponding working efficiency of multiple sets of associated speed-torque points, multiple energy consumption parameters P of the target motor at multiple sets of associated speed-torque points are calculated by the following formula (1): loss,i,j .

[0094]

[0095] Wherein, j={1,2,3} in the above formula (1) corresponds to three driving modes (such as front-wheel drive mode, dual-motor rear-wheel drive mode and four-wheel drive mode), and i={f,rl,rr} corresponds to three motors (such as f is the front axle motor, rl is the right rear wheel motor, and rr is the left rear wheel motor); P loss,i,j is the energy loss of target motor i in mode j, η is the efficiency of the current working point; T is the torque, and ω is the speed.

[0096] It should be noted that multiple energy consumption parameters can be used to reflect the energy usage of the target motor at different speed torque points, which comprehensively consider factors such as the working efficiency, output power, and operating time of the target motor. Different speed torque points may lead to different combinations of these parameters, thereby affecting the final energy consumption. Through the comprehensive analysis of multiple energy consumption parameters, the energy consumption of each speed torque point can be more comprehensively evaluated to avoid incomplete energy consumption optimization caused by considering only a single factor.

[0097] S403 . According to the multiple energy consumption parameters, determine the speed-torque point with the minimum energy consumption parameter from the multiple groups of associated speed-torque points as the target speed-torque point.

[0098] In a possible implementation, multiple energy consumption parameters P are obtained according to the above formula (1): loss,i,j, and then use the following formula (2) to calculate multiple energy consumption parameters P under multiple sets of related speed and torque points loss,i,j In the process, determine the speed torque point with the minimum energy consumption parameter.

[0099]

[0100] Among them, after the speed-torque point with the minimum energy consumption parameter is obtained according to the above formula (2), the speed-torque point with the minimum energy consumption parameter is used as the target speed-torque point. By determining the speed-torque point with the minimum energy consumption parameter as the target speed-torque point, the principle of optimal energy consumption is followed, so that the target vehicle can travel a longer distance with the same battery power or fuel reserve.

[0101] It should be noted that after the speed torque point with the minimum energy consumption parameter is calculated according to formula (2), the speed torque point with the minimum energy consumption parameter needs to be stored in the energy consumption table in the vehicle controller for later allocation and query.

[0102] The energy management method for three-motor drive provided in the present application, if the current driving state is the forward state, obtains the work efficiency corresponding to multiple groups of related speed torque points from the work efficiency diagram of the target motor respectively, so as to accurately understand the energy conversion efficiency of the target motor under different working conditions, thereby ensuring that the motor can output the speed and torque that match the vehicle driving requirements under different forward working conditions. According to the speed, torque and corresponding work efficiency of multiple groups of related speed and torque points, calculate the multiple energy consumption parameters of the target motor under multiple groups of related speed torque points respectively, so as to accurately judge the energy consumption under various speed torque combinations; according to multiple energy consumption parameters, determine the speed torque point with the smallest energy consumption parameter from multiple groups of related speed torque points as the target speed torque point, so that the target motor can always maintain a low energy consumption working state during the forward process, effectively reducing unnecessary energy loss, thereby extending the cruising range of the target vehicle and improving the user experience.

[0103] Optionally, the above-mentioned driving demand parameter may include: a current rotation speed ω of the target motor.

[0104] In a possible implementation, the above method uses the working efficiency diagram of the target motor in the current driving mode according to the driving demand parameters to obtain multiple groups of associated speed torque points that meet the preset matching conditions with the driving demand parameters, which may include:

[0105] According to the current rotational speed, a plurality of associated rotational speeds having a rotational speed deviation from the current rotational speed within a preset rotational speed deviation range and torques corresponding to the plurality of associated rotational speeds are determined using a working efficiency diagram of the target motor.

[0106] Each set of associated speed-torque points includes: an associated speed and a corresponding torque. The preset speed deviation range can be selected according to actual conditions, for example, the preset speed deviation range can be selected as 5%.

[0107] In one possible implementation, by reading the working efficiency diagram of the target motor and taking the current speed ω as a reference, a plurality of associated speeds within a preset speed deviation range (such as 5%) are determined, each associated speed has its corresponding torque, and a plurality of associated speeds and the torques corresponding to the plurality of associated speeds constitute a plurality of groups of associated speed torque points.

[0108] It should be noted that the target motor speed will change according to the actual working conditions during the driving of the vehicle. By setting a preset speed deviation range (such as 5%), the fluctuation of the target motor speed under different driving scenarios can be flexibly considered.

[0109] The energy management method for three-motor drive provided in the present application, the drive demand parameter can be composed of the current speed of the target motor. According to the current speed, the work efficiency diagram of the target motor is used to determine multiple related speeds whose speed deviation from the current speed is within a preset speed deviation range and the torques corresponding to the multiple related speeds, so as to provide richer information for the control of the target motor by obtaining multiple related speed-torque points. Compared with only focusing on the current speed and torque, considering multiple points within the speed deviation range can more comprehensively understand the performance of the target motor under different working conditions. This helps the vehicle controller to select the optimal working point according to the actual situation, so as to maximize the working efficiency of the target motor and reduce energy consumption while ensuring power output.

[0110] Optionally, the above-mentioned driving demand parameters may also include: the opening and closing degree θ of the accelerator pedal and the current vehicle speed v.

[0111] In a possible implementation, before distributing energy to the target motor according to the target speed torque point in the above method, the method may further include:

[0112] According to the opening and closing degree of the accelerator pedal and the current vehicle speed, the target acceleration torque corresponding to the target motor is calculated.

[0113] In one possible implementation, the basic torque Tb is calculated according to the opening and closing degree θ of the accelerator pedal through the basic torque mapping function Tb=f(θ), and then the torque correction coefficient k is calculated according to the current vehicle speed v through the torque correction coefficient function k=g(v).

[0114] Among them, the basic torque mapping function Tb is set based on the vehicle's power performance requirements and driving habits, and is a linear function or piecewise linear function. The torque correction coefficient function k is obtained through dynamic analysis of the target vehicle at different speeds and experimental data fitting; if the current vehicle speed v is low, the correction coefficient k may be close to 1; as the current vehicle speed v increases, k will gradually increase to reflect the increase in acceleration difficulty when driving at high speeds.

[0115] Then, the target acceleration torque Ta corresponding to the target motor is calculated according to the following formula (3).

[0116] Ta=Tb×k formula (3)

[0117] By using the above formula (3), the target acceleration torque corresponding to the comprehensive consideration of the accelerator pedal opening and closing degree and the current vehicle speed can be obtained.

[0118] Figure 6 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 3 .like Figure 6 As shown, in the above method, energy distribution to the target motor according to the target speed torque point may include:

[0119] S501 , determining whether the torque at the target speed torque point is greater than or equal to the target acceleration torque.

[0120] In one possible implementation, it is determined whether the torque at the target speed torque point is greater than or equal to the target acceleration torque, so as to determine whether the torque provided by the target motor is sufficient to meet the power demand of the target vehicle acceleration while satisfying the minimum energy consumption. If so, step S502 is executed; if not, step S503 is executed.

[0121] S502: If the torque at the target speed torque point is greater than or equal to the target acceleration torque, the speed and torque at the target speed torque point are both allocated to the target motor.

[0122] In one possible implementation, if the torque at the target speed torque point is greater than or equal to the target acceleration torque, it means that the target vehicle can provide sufficient power to achieve acceleration while achieving optimal energy consumption; the speed and torque at the target speed torque point can be allocated to the target motor to ensure that the motor operates at the lowest energy consumption point, thereby effectively reducing energy waste. For example, when the target vehicle is driving normally and the acceleration demand is small, using the speed torque point with the lowest energy consumption can significantly reduce the target vehicle's electric energy or fuel consumption and extend the cruising range.

[0123] S503. If the torque of the target speed torque point is less than the target acceleration torque, another speed torque point whose torque is greater than or equal to the target speed torque point is determined from multiple groups of associated speed torque points, and the torque of the target speed torque point is first allocated to the target motor. When the speed of the target motor reaches the speed of the other speed torque point, the torque of the other speed torque point is allocated to the target motor.

[0124] In one possible implementation, if the torque at the target speed torque point is less than the target acceleration torque, the torque at the target speed torque point is allocated first, and the corresponding torque is allocated after the target motor speed reaches the speed of another speed torque point. This is to avoid using a high-energy consumption working point at the beginning, but to gradually adjust it to control the increase in energy consumption as much as possible while meeting the acceleration requirements. For example, when the target vehicle needs to accelerate sharply, it will not switch to a high-energy consumption working state instantly, but there will be a transition process, which balances the relationship between power demand and energy consumption to a certain extent.

[0125] The energy management method for three motor drives provided by the present application, the driving demand parameter can also be composed of the opening and closing degree of the accelerator pedal and the current vehicle speed; and according to the opening and closing degree of the accelerator pedal and the current vehicle speed, the target acceleration torque corresponding to the target motor is calculated; if the torque of the target speed torque point is greater than or equal to the target acceleration torque, the speed and torque of the target speed torque point are both allocated to the target motor; if the torque of the target speed torque point is less than the target acceleration torque, another speed torque point whose torque is greater than or equal to is determined from multiple groups of associated speed torque points, and the torque of the target speed torque point is first allocated to the target motor, and when the speed of the target motor reaches the speed of another speed torque, the torque of the other speed torque point is allocated to the target motor. Thus, the present application can adopt a method of gradually switching the speed torque point when the torque of the target speed torque point is insufficient, so that the torque output of the target motor can be smoothly transitioned, avoiding the vehicle frustration caused by torque mutation. For example, in the process of accelerating the target vehicle from low speed to high speed, this smooth torque switching can make the driver and passengers feel a more comfortable driving experience, and also help to protect the transmission system of the target vehicle and reduce the wear of components caused by torque shock.

[0126] Figure 7 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 4 .like Figure 7 As shown, in the above method, determining the target speed torque point from a plurality of sets of associated speed torque points according to the current driving state may include:

[0127] S601: If the current driving state is a braking state, respectively obtain working efficiencies corresponding to a plurality of groups of associated speed torque points from a working efficiency diagram of the target motor.

[0128] In one possible implementation, if the current driving state of the target vehicle is a braking state, that is, the target vehicle is converting kinetic energy into electrical energy for recovery, or assisting deceleration through mechanical braking, etc., then obtaining the working efficiency corresponding to multiple groups of related speed torque points from the working efficiency diagram of the target motor is helpful to fully understand the energy conversion efficiency of the target motor at different speed and torque combinations, as well as its performance during braking.

[0129] S602, respectively calculating a plurality of energy recovery parameters of the target motor at the plurality of sets of associated speed-torque points according to the speeds, torques and corresponding working efficiencies of the plurality of sets of associated speed-torque points.

[0130] In one possible implementation, according to the speed, torque and corresponding working efficiency of multiple sets of associated speed and torque points, multiple energy recovery parameters P of the target motor at multiple sets of associated speed and torque points are calculated by the following formula (4): re (t,u).

[0131] P re (t,u)=T i,j ·ω i,j ·η(T i,j ,ω i,j ), (0≤T i ≤T max,i , 0≤ω i ≤ω max,i )

[0132] Formula (4)

[0133] S603 . According to the plurality of energy recovery parameters, determine the speed-torque point with the maximum energy recovery parameter from the plurality of groups of associated speed-torque points as the target speed-torque point.

[0134] In a possible implementation, multiple energy recovery parameters P are obtained according to the above formula (4): re (t,u), and then use the following formula (5) to obtain multiple energy recovery parameters P from multiple sets of related speed torque points re In (t,u), determine the speed torque point where the energy recovery parameter is maximum.

[0135]

[0136] Among them, after obtaining the speed torque point with the maximum energy recovery parameter according to the above formula (5), the speed torque point with the maximum energy recovery parameter is used as the target speed torque point. By determining the speed torque point with the maximum energy recovery parameter as the target speed torque point, the target motor can work in a relatively ideal state during the braking process, avoiding the target motor from operating at an inappropriate speed torque and generating excessive load. For example, when the target motor works at a speed torque point with low energy recovery efficiency, it may consume more electric energy to achieve braking, or generate greater mechanical stress, which will cause damage to the target motor. By selecting the optimal target speed torque point, the burden on the target motor can be reduced and the service life of the target motor can be extended.

[0137] It should be noted that after the speed torque point with the maximum energy recovery parameter is calculated according to formula (5), the speed torque point with the maximum energy recovery parameter needs to be stored in the energy table of the vehicle controller for later distribution and query.

[0138] The energy management method for three-motor drive provided in the present application, if the current driving state is a braking state, then the work efficiencies corresponding to multiple groups of related speed-torque points are obtained from the work efficiency diagram of the target motor; based on the speeds, torques and corresponding work efficiencies of the multiple groups of related speed-torque points, multiple energy recovery parameters of the target motor under the multiple groups of related speed-torque points are calculated respectively; based on the multiple energy recovery parameters, the speed-torque point with the largest energy recovery parameter is determined from the multiple groups of related speed-torque points as the target speed-torque point, so as to accurately find the working point with the highest energy recovery efficiency under the braking state, that is, the target speed-torque point, which enables the target motor to convert as much kinetic energy of the target vehicle into electrical energy as possible during braking, thereby improving the energy recovery efficiency, increasing the cruising range of the target vehicle, providing energy support for subsequent driving, and thereby improving the overall reliability and stability of the target vehicle.

[0139] Optionally, the driving demand parameters may include: the opening and closing degree θ of the brake pedal and the current vehicle speed v, or a preset energy recovery level. The preset energy recovery level may be selected according to the energy recovery level set on the central control screen of the target vehicle.

[0140] Figure 8 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 5 .like Figure 8 As shown, in the above method, according to the drive demand parameters, the working efficiency diagram of the target motor in the current drive mode is used to obtain multiple groups of associated speed torque points that meet the preset matching conditions with the drive demand parameters, which may include:

[0141] S701. Determine a target counter-torque according to the degree of opening and closing of the brake pedal and the current vehicle speed, or a preset energy recovery level.

[0142] In one possible implementation, when the target vehicle is in a braking state (or a coasting state), the target acceleration torque Ta corresponding to the target motor in the braking state is obtained according to the opening and closing degree of the brake pedal and the current vehicle speed according to the above formula (3), and then the target counter-torque is obtained according to the target acceleration torque Ta.

[0143] Alternatively, when the target vehicle is in a braking state (or a coasting state), the target counter-torque is determined according to a corresponding relationship between a preset energy recovery level in a preset energy recovery level and the counter-torque.

[0144] Among them, the target reverse torque is to achieve the dynamic state of the target vehicle for braking or energy recovery, and the target motor is expected to generate a reverse torque. The reverse torque can be used to determine the torque value that the target motor needs to achieve when working to meet the actual operation needs of the vehicle.

[0145] S702: According to the target counter-torque, determine from a working efficiency diagram of the target motor a plurality of associated speeds whose torque deviation from the target counter-torque is within a preset torque deviation range and torques corresponding to the plurality of associated speeds.

[0146] Each set of associated speed torque points includes: an associated speed and a corresponding torque. The preset torque deviation range is to balance the control accuracy and the actual operability, and can be selected according to the actual situation. For example, the preset torque deviation range can be selected as 5%.

[0147] In one possible implementation, based on the target counter-torque, multiple points whose torque deviation from the target counter-torque is within a preset torque deviation range (such as 5%) are found from the target motor's operating efficiency diagram, and based on these multiple points, corresponding multiple associated speeds and the torques corresponding to the multiple associated speeds are found.

[0148] Among them, multiple associated speeds are the speeds corresponding to the case where the target motor can produce a target anti-torque close to the target. They reflect the possibility of the target motor achieving the target anti-torque at different operating speeds, which helps to understand the speed range in which the target motor can effectively produce the required anti-torque, and provides a basis for speed selection for the subsequent control strategy formulation. For the torque corresponding to multiple associated speeds, it is necessary to more accurately understand the output capacity of the target motor at different speeds and the specific deviation from the target anti-torque. This is very important for accurately controlling the output of the target motor to make it as close to the target anti-torque as possible, which helps to achieve more accurate energy recovery, braking control or other torque-related control tasks.

[0149] The energy management method of three motor drives provided in the present application, the driving demand parameter can be composed of the opening and closing degree of the brake pedal and the current vehicle speed, or by the preset energy recovery level; according to the opening and closing degree of the brake pedal and the current vehicle speed, or the preset energy recovery level, the target anti-torque is determined so that the energy recovery system can more accurately match the actual braking demand of the target vehicle. For example, in a congested urban road condition, the target vehicle frequently decelerates by lightly pressing the brake pedal. At this time, the vehicle controller can determine a smaller target anti-torque according to the small opening and closing degree of the pedal and the low speed. The target motor recovers energy with a relatively low power, which can effectively recover part of the kinetic energy without excessively affecting the deceleration process of the target vehicle. When emergency braking is required for high-speed driving, a larger pedal opening and closing degree and a higher vehicle speed will correspond to a larger target anti-torque, and the motor will fully recover energy, improve energy recovery efficiency, and increase the cruising range of the target vehicle; or, the target anti-torque is determined by presetting the energy recovery level, giving the driver more autonomous control. The driver can choose different energy recovery levels according to his driving habits and road conditions. For example, on a long downhill section, a high energy recovery level is selected, the vehicle controller will determine a larger target counter-torque, and the target motor will generate a stronger braking force, which can not only effectively recover energy, but also assist the target vehicle in controlling the speed, reduce the frequency of mechanical braking, and reduce the wear of the brake pads. According to the target counter-torque, multiple associated speeds and torques corresponding to multiple associated speeds with a torque deviation from the target counter-torque within a preset torque deviation range are determined from the target motor's work efficiency diagram. Each set of associated speed-torque points includes: an associated speed and a corresponding torque, so that the braking force provided by the target motor during braking is smoother and more linear. This can avoid the target vehicle from being jerked due to sudden changes in braking force, improve driving comfort, and thus improve the adaptability and reliability of the vehicle drive system.

[0150] Optionally, in the above method, allocating energy to the target motor according to the target speed torque point may include:

[0151] The speed and torque at the target speed torque point are distributed to the target motor.

[0152] In one possible implementation, the speed and torque corresponding to the target speed torque point are allocated to the target motor according to the target speed torque point found. When the target vehicle is in a braking state, the target motor is operated at the target speed to achieve the best energy recovery effect. For example, if the target speed is too high, the target motor may exceed its efficient working range, resulting in reduced energy recovery efficiency and even damage to the target motor; while if the target speed is too low, the kinetic energy of the target vehicle cannot be fully utilized, and less energy is recovered. The distribution of the target torque directly affects the braking force generated by the target motor. If the torque is too large, the target vehicle may brake too hastily, affecting ride comfort, and may even cause wheel locking, endangering driving safety; if the torque is too small, it cannot provide sufficient braking force, cannot effectively achieve energy recovery, and cannot meet the braking requirements of the target vehicle.

[0153] It should be noted that when the target vehicle is in a forward state, the speed and torque of the target speed torque point are also distributed to the target motor, so that the target motor can output appropriate driving force to push the target vehicle forward. At this time, the speed determines the driving speed of the target vehicle, and the torque determines the acceleration and climbing ability of the target vehicle. Reasonable speed torque distribution needs to consider the efficiency characteristics of the target motor, the power supply capacity of the battery, and the overall performance requirements of the target vehicle to achieve the best power output and energy utilization efficiency.

[0154] The energy management method for three-motor drive provided by the present application allocates the speed and torque of the target speed torque point to the target motor. Therefore, the present application can allocate the speed and torque of the target speed torque point acquired to the target motor according to the current driving state of the target vehicle, thereby avoiding damage to the target motor due to abnormal conditions such as overload or overspeed, extending the service life of the target motor, reducing maintenance costs, and improving the reliability and safety of the target vehicle.

[0155] Optionally, the target motor includes: two rear-drive motors; namely, a left rear-drive motor and a right rear-drive motor.

[0156] In a possible implementation, the method for allocating energy to the target motor according to the target speed torque point may include:

[0157] The same target speed and torque are distributed to the two rear drive motors.

[0158] In one possible implementation, when the target motors are two rear-drive motors, the target speed torques of the two rear-drive motors must be consistent, so that the two rear-drive motors drive the rear wheels of the vehicle at the same speed and force, so that the target vehicle obtains balanced power output. This helps maintain the stability of the target vehicle in straight-line driving and avoids the target vehicle from running off the track or having an unstable driving posture due to inconsistent power output of the motors on both sides.

[0159] It should be noted that although the same speed and torque are assigned to the two rear-drive motors, the actual loads borne by the two rear-drive motors are often different due to the differences in the motor's own characteristics and the inconsistent resistance of the left and right wheels when the vehicle is driving. In the long run, one of the rear-drive motors may be under greater pressure and wear faster, thereby shortening the service life of the rear-drive motor and reducing its reliability. To solve this problem, the preset wheel slip rate can be used for judgment. When the wheel slip rate of the two rear-drive motors is within the preset range, it indicates that the working conditions of the motors on both sides are similar, and it can be considered that the two rear-drive motors are adapted to the same target speed and torque.

[0160] The energy management method of three-motor drive provided in this application, if the target motor includes: two rear-drive motors; the same target speed torque is allocated to the two rear-drive motors so that the two rear-drive motors can work together better to cope with various working conditions during the driving process of the target vehicle. For example, when accelerating, climbing or encountering a large driving resistance, the two rear-drive motors can output the same power at the same time to provide sufficient driving force; when driving at a constant speed, they can maintain a consistent operating state and reduce energy consumption. This collaborative working mode helps to improve the overall performance and efficiency of the target vehicle.

[0161] To facilitate understanding of the above three-motor drive energy management method, the present application embodiment further provides an example of a process of a three-motor drive energy management method, which is described below in conjunction with the accompanying drawings. Figure 9 A schematic diagram of a three-motor drive energy management method provided in an embodiment of the present application Figure 6 .like Figure 9 As shown, the schematic diagram provided by the embodiment of the present application Figure 6 This may include:

[0162] S801. Obtain the current driving state, current driving mode, and driving demand parameters under the current driving state of the target vehicle.

[0163] Specifically, the driving state of the target vehicle itself is determined by the relevant data transmitted by various sensors arranged on the target vehicle. Such as braking state (or sliding state), or forward state, wherein the forward state includes accelerating driving state, or uniform driving state, or decelerating driving (non-braking deceleration) state, etc. Since the vehicle controller communicates with the front drive motor controller and the two rear drive motor controllers, the current driving mode of the target vehicle can be determined by the data obtained by the vehicle controller. Among them, if the current driving mode is the first driving mode (front drive mode), the target motor is the front drive motor; if the current driving mode is the second driving mode (dual motor rear drive mode), the target motor includes: two rear wheel drive motors; if the current driving mode is the third driving mode (four-wheel drive mode), the target motor includes: front drive motor and two rear wheel drive motors. Then, according to the current driving state of the target vehicle (such as forward state, braking state, sliding state, etc.) and the current driving mode, the driving demand parameters of the target vehicle are determined.

[0164] S802. If the current driving state of the target vehicle is in the forward state, according to the working efficiency diagram of the target motor under the current driving mode, multiple groups of associated speed-torque points that meet the preset matching conditions with the driving demand parameters are obtained, and the target speed-torque point is determined from the multiple groups of associated speed-torque points, and energy is distributed to the target motor.

[0165] Specifically, if the current driving state of the target vehicle is in the forward state, and the current driving mode is the front drive mode, the vehicle controller of the target vehicle calculates the corresponding target acceleration torque Ta according to the opening and closing degree θ of the accelerator pedal and the current vehicle speed v through the above formula (3). Then, the vehicle controller traverses the torque-speed-energy consumption table calculated and stored before through the current speed and current torque of the front drive motor at this time, and selects multiple associated speed torque points whose current speed deviation of the front drive motor is within the preset speed deviation range, for example, the multiple associated speed torque points are (n1, T1), (n2, T2), (n3, T3), where (n2, T2) is the optimal energy consumption point corresponding to the current drive motor, that is, (n2, T2) is the target speed torque point, and the torque of the target speed torque point is greater than or equal to the target acceleration torque Ta, that is, (n2, T2) meets the acceleration torque requirement of the target vehicle, and the speed T2 and torque n2 of the target speed torque point are both allocated to the front drive motor.

[0166] If (n2, T2) does not meet the target acceleration torque Ta, but (n3, T3) meets the target acceleration torque Ta, then only T2 in (n2, T2) needs to be given to the torque of the front axle motor, and when the current speed of the front drive motor is accelerated to n3, the torque of the front drive motor is adjusted to T3. This allocation process is a dynamic optimization process to ensure that the target vehicle can better utilize the energy of the power battery and improve the driving range of the target vehicle.

[0167] It should be noted that if the current driving state of the target vehicle is in the forward state and the current driving mode is the dual-motor rear-drive mode, the energy distribution method of the two rear-drive motors is the same as the energy distribution method in the front-drive mode, which will not be repeated here.

[0168] If the current driving state of the target vehicle is in the forward state, and the current driving mode is the four-wheel drive mode, the vehicle control ball calculates the optimal working torque and speed of the three motors through formula (2), and distributes the torque and speed to the front axle motor, the left rear wheel motor, and the right rear wheel motor. If the target vehicle has an acceleration request, the torque required for the target vehicle to drive is determined according to the opening and closing degree of the accelerator pedal and the signal of the wheel speed sensor; the torque-speed-energy consumption table calculated previously is traversed, and the torque of the three motors corresponding to the maximum efficiency at this speed is selected according to the motor speed. Since the three motors are different, the vehicle controller should ensure that the torque of the left rear wheel motor is equal to the torque of the right rear wheel motor, and the front axle torque is increased on this basis for the insufficient torque; if the target vehicle is driving at a constant speed at this time, and the opening and closing degree of the accelerator pedal has not changed, the vehicle controller only needs to adjust the torque of the front axle motor appropriately at the current vehicle speed to ensure that the energy consumption of the whole vehicle is at the optimal energy consumption in real time. In order to ensure the safety of the target vehicle, the torque of the left and right wheels and the right rear wheel motor is not adjusted.

[0169] S803. If the current driving state of the target vehicle is in a braking state, based on the working efficiency diagram of the target motor under the current driving mode, multiple groups of associated speed-torque points that meet preset matching conditions with the driving demand parameters are obtained, and the target speed-torque point is determined from the multiple groups of associated speed-torque points, and energy is distributed to the target motor.

[0170] Specifically, if the current driving state of the target vehicle is in a braking state, and the current driving mode is a front-wheel drive mode, at this time, the front axle motor provides feedback torque, and the target reverse torque is determined according to the preset energy recovery level set on the vehicle's central control screen, and the vehicle controller sends the target reverse torque to the front-wheel drive motor controller. The front-wheel drive motor controller traverses the torque-energy table calculated previously, and selects a plurality of associated speed torque points whose current torque deviation of the front-wheel drive motor is within the preset torque deviation range, for example, the plurality of associated speed torque points are (n1, T1), (n2, T2), and (n3, T3), wherein (n2, T2) is the speed torque point with the maximum energy recovery parameter corresponding to the current drive motor, that is, (n2, T2) is the target speed torque point, that is, (n2, T2) satisfies the braking torque requirement of the target vehicle, that is, satisfies the target reverse torque, and the speed T2 and torque n2 of the target speed torque point are both allocated to the front-wheel drive motor, and then the energy recovered in this state is calculated and stored according to the above formula (5).

[0171] If the current driving state of the target vehicle is in the braking state, and the current driving mode is the dual-motor rear-wheel drive mode, the two rear-wheel drive motors provide feedback torque at the same time. The vehicle controller distributes the torque and speed calculated in the query formula (5) to the two rear-wheel drive motors. Since the torques of the two rear-wheel drive motors must be equal, or the wheel slip rate is within the preset wheel slip rate range, at this time, in addition to mechanical braking, in order to improve the vehicle's cruising range, the power battery needs to be reversely charged. The two rear-wheel drive motors need to provide reverse torque at the same time to perform reverse additional braking on the target vehicle. The reverse torque of the two rear-wheel drive motors generates feedback current to reversely charge the power battery.

[0172] If the current driving state of the target vehicle is in a braking state and the current driving mode is a four-wheel drive mode, the energy distribution method of the front drive motor and the two rear drive motors is the same as the energy distribution method when the current driving state of the target vehicle is in a forward state, and will not be repeated here.

[0173] The energy management method of three-motor drive provided by the present application obtains the current driving state, current driving mode and driving demand parameters of the target vehicle under the current driving state; if the current driving state of the target vehicle is in the forward state, according to the working efficiency diagram of the target motor under the current driving mode, multiple groups of associated speed torque points that meet the preset matching conditions with the driving demand parameters are obtained, and the target speed torque point is determined from the multiple groups of associated speed torque points, and the target motor performs energy distribution; if the current driving state of the target vehicle is in the braking state, according to the working efficiency diagram of the target motor under the current driving mode, multiple groups of associated speed torque points that meet the preset matching conditions with the driving demand parameters are obtained, and the target speed torque point is determined from the multiple groups of associated speed torque points, and the target motor performs energy distribution. Therefore, the present application can solve the problem of excessive energy consumption of distributed drive electric vehicles during operation, and by adopting a calibrated MAP diagram, the energy consumption during the operation of the whole vehicle and the safety during the mode switching process are controlled, the driving range of the target vehicle is improved, and the energy of the power battery is better utilized.

[0174] Based on the same inventive concept, a three-motor driven energy management device is also provided in an embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned three-motor driven energy management method in the embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0175] Figure 10 This is a schematic diagram of the structure of a three-motor driven energy management device provided in an embodiment of the present application. Figure 10 As shown, the three-motor driven energy management device 90 may include: a first acquisition module 91 , a second acquisition module 92 , a determination module 93 and an allocation module 94 .

[0176] A first acquisition module 91 is used to acquire the current driving state, the current driving mode and the driving demand parameters under the current driving state of the target vehicle;

[0177] A second acquisition module 92 is used to acquire, according to the drive demand parameters, a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameters by using a working efficiency diagram of the target motor in the current drive mode;

[0178] A determination module 93, for determining a target speed torque point from a plurality of sets of associated speed torque points according to a current driving state;

[0179] The allocation module 94 is used to allocate energy to the target motor according to the target speed torque point.

[0180] In an optional embodiment, the determination module 93 is specifically used to: if the current driving state is the forward state, respectively obtain the work efficiency corresponding to multiple groups of related speed-torque points from the work efficiency diagram of the target motor; calculate multiple energy consumption parameters of the target motor under the multiple groups of related speed-torque points according to the speed, torque and corresponding work efficiency of the multiple groups of related speed-torque points; and determine, according to the multiple energy consumption parameters, the speed-torque point with the smallest energy consumption parameter from the multiple groups of related speed-torque points as the target speed-torque point.

[0181] In an optional embodiment, the drive demand parameters include: the current speed of the target motor; a second acquisition module 92, specifically used to: based on the current speed, use the work efficiency diagram of the target motor to determine multiple associated speeds whose speed deviation from the current speed is within a preset speed deviation range and the torques corresponding to the multiple associated speeds, each group of associated speed-torque points includes: an associated speed and a corresponding torque.

[0182] In an optional embodiment, the drive demand parameters also include: the opening degree of the accelerator pedal and the current vehicle speed; the allocation module 94 is also used to: calculate the target acceleration torque corresponding to the target motor according to the opening degree of the accelerator pedal and the current vehicle speed; the allocation module 94 is specifically used to: if the torque of the target speed torque point is greater than or equal to the target acceleration torque, then the speed and torque of the target speed torque point are allocated to the target motor; if the torque of the target speed torque point is less than the target acceleration torque, then determine another speed torque point whose torque is greater than or equal to the target speed torque from multiple groups of associated speed torque points, first allocate the torque of the target speed torque point to the target motor, and when the speed of the target motor reaches the speed of another speed torque point, allocate the torque of the other speed torque point to the target motor.

[0183] In an optional embodiment, the determination module 93 is specifically used to: if the current driving state is a braking state, obtain the work efficiencies corresponding to multiple groups of associated speed-torque points from the work efficiency diagram of the target motor; calculate multiple energy recovery parameters of the target motor at the multiple groups of associated speed-torque points according to the speeds, torques and corresponding work efficiencies of the multiple groups of associated speed-torque points; and determine, according to the multiple energy recovery parameters, the speed-torque point with the largest energy recovery parameter from the multiple groups of associated speed-torque points as the target speed-torque point.

[0184] In an optional embodiment, the drive demand parameters include: the opening degree of the brake pedal and the current vehicle speed, or a preset energy recovery level; the second acquisition module 92 is specifically used to: determine the target counter-torque according to the opening degree of the brake pedal and the current vehicle speed, or the preset energy recovery level; according to the target counter-torque, determine from the working efficiency diagram of the target motor a plurality of associated speeds whose torque deviation from the target counter-torque is within a preset torque deviation range and the torques corresponding to the plurality of associated speeds, each group of associated speed-torque points including: an associated speed and a corresponding torque.

[0185] In an optional implementation, the allocation module 94 is specifically configured to allocate the speed and torque of the target speed torque point to the target motor.

[0186] In an optional implementation, if the target motor includes: two rear-drive motors; the allocation module 94 is specifically used to: allocate the same target speed torque to the two rear-drive motors.

[0187] It should be noted that for details not disclosed in the three-motor driven energy management device of the embodiment of the present application, please refer to the details disclosed in the three-motor driven energy management method of the embodiment of the present application, and the details will not be repeated here.

[0188] The above modules may be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASICs), or one or more microprocessors, or one or more field programmable gate arrays (FPGAs). For another example, when a module is implemented in the form of a processing element scheduling program code, the processing element may be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call program code. For another example, these modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0189] Optionally, the embodiment of the present application further provides a readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the processor executes the steps of the energy management method of the three-motor drive of the mobile storage medium in the above embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0190] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0191] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to perform some steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (English: Read-Only Memory, abbreviated: ROM), random access memory (English: Random Access Memory, abbreviated: RAM), disk or optical disk and other media that can store program codes.

[0192] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A three-motor drive energy management method, characterized in that: include: Acquire the current driving state, current driving mode and driving demand parameters under the current driving state of the target vehicle; According to the drive demand parameter, a working efficiency diagram of the target motor in the current drive mode is used to obtain a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter; Determining a target speed torque point from the plurality of sets of associated speed torque points according to the current driving state; Energy is distributed to the target motor according to the target speed torque point.

2. The energy management method of three-motor drive according to claim 1, characterized in that: The step of determining the target speed torque point from the plurality of groups of associated speed torque points according to the current driving state includes: If the current driving state is a forward state, respectively obtaining the working efficiencies corresponding to the plurality of groups of associated speed torque points from the working efficiency diagram of the target motor; Calculating a plurality of energy consumption parameters of the target motor at the plurality of sets of associated speed-torque points according to the speeds, torques and corresponding working efficiencies of the plurality of sets of associated speed-torque points; According to the multiple energy consumption parameters, a speed-torque point with the minimum energy consumption parameter is determined from the multiple groups of associated speed-torque points as the target speed-torque point.

3. The energy management method of three-motor drive according to claim 2, characterized in that: The drive demand parameter includes: the current speed of the target motor; according to the drive demand parameter, using the working efficiency diagram of the target motor under the current drive mode, obtaining a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter, including: According to the current speed, the working efficiency diagram of the target motor is used to determine multiple associated speeds whose speed deviation from the current speed is within a preset speed deviation range and the torques corresponding to the multiple associated speeds, each group of associated speed-torque points includes: an associated speed and a corresponding torque.

4. The energy management method of three-motor drive according to claim 2, characterized in that: The driving demand parameters also include: the opening and closing degree of the accelerator pedal and the current vehicle speed; Before distributing energy to the target motor according to the target speed torque point, the method further includes: Calculating a target acceleration torque corresponding to the target motor according to the opening and closing degree of the accelerator pedal and the current vehicle speed; The energy distribution to the target motor according to the target speed torque point includes: If the torque at the target speed torque point is greater than or equal to the target acceleration torque, allocating the speed and torque at the target speed torque point to the target motor; If the torque of the target speed torque point is less than the target acceleration torque, another speed torque point whose torque is greater than or equal to the target speed torque is determined from the multiple groups of associated speed torque points, and the torque of the target speed torque point is first allocated to the target motor, and when the speed of the target motor reaches the speed of the another speed torque, the torque of the another speed torque point is allocated to the target motor.

5. The energy management method of three-motor drive according to claim 1, characterized in that: The step of determining the target speed torque point from the plurality of groups of associated speed torque points according to the current driving state includes: If the current driving state is a braking state, respectively obtaining the working efficiencies corresponding to the plurality of groups of associated speed torque points from the working efficiency diagram of the target motor; Calculating a plurality of energy recovery parameters of the target motor at the plurality of sets of associated speed and torque points respectively according to the speeds, torques and corresponding working efficiencies of the plurality of sets of associated speed and torque points; According to the multiple energy recovery parameters, a speed torque point with the maximum energy recovery parameter is determined from the multiple groups of associated speed torque points as the target speed torque point.

6. The energy management method of three-motor drive according to claim 5, characterized in that: The driving demand parameters include: the opening and closing degree of the brake pedal and the current vehicle speed, or a preset energy recovery level; The step of obtaining, according to the drive demand parameter, a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter by using the work efficiency diagram of the target motor under the current drive mode comprises: determining a target reverse torque according to the opening and closing degree of the brake pedal and the current vehicle speed, or the preset energy recovery level; According to the target counter-torque, multiple associated speeds whose torque deviation from the target counter-torque is within a preset torque deviation range and the torques corresponding to the multiple associated speeds are determined from the working efficiency diagram of the target motor, and each group of associated speed-torque points includes: an associated speed and a corresponding torque.

7. The energy management method of three-motor drive according to claim 5, characterized in that: The energy distribution to the target motor according to the target speed torque point includes: The speed and torque at the target speed torque point are distributed to the target motor.

8. The energy management method of three-motor drive according to claim 1, characterized in that: If the target motor includes: two rear drive motors; The energy distribution to the target motor according to the target speed torque point includes: The same target speed torque is allocated to the two rear-drive motors.

9. A three-motor driven energy management device, characterized in that: include: A first acquisition module, used to acquire the current driving state, the current driving mode and the driving demand parameters under the current driving state of the target vehicle; A second acquisition module is used to acquire, according to the drive demand parameter, a plurality of groups of associated speed torque points that meet preset matching conditions with the drive demand parameter by using a working efficiency diagram of the target motor in the current drive mode; A determination module, configured to determine a target speed torque point from the plurality of sets of associated speed torque points according to the current driving state; The allocation module is used to allocate energy to the target motor according to the target speed torque point.

10. A vehicle driving system, characterized in that: include: Vehicle controller, front drive motor controller, front drive motor, front drive reducer, differential, two rear drive motor controllers, two rear drive motors and two rear drive reducers; The front drive motor is connected to the differential of the front wheel axle through the front drive reducer; the two rear drive motors drive the rear drive reducers connected to the two rear wheels respectively; The front drive motor controller is connected to the front drive motor, and the two rear drive motor controllers are respectively connected to the two rear drive motors; The vehicle controller is communicatively connected to the front-drive motor controller and the two rear-drive motor controllers, and the vehicle controller is used to execute the methods described in claims 1 to 8 above.

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