Method, device, medium and vehicle for reducing energy consumption of whole vehicle

Abstract

The present invention provides a method, device, medium and vehicle for reducing the energy consumption of a whole vehicle, the method comprising: constructing a whole vehicle energy consumption target function according to the bus loss of a microcontroller, the mechanical loss of the wheel end and the working loss of the oil pump; calibrating the motor speed, oil temperature, motor torque and oil pump flow of the vehicle according to the whole vehicle energy consumption target function to obtain an optimal loss calibration file; during the driving of the vehicle, obtaining the current speed of the motor and the current oil temperature of the oil pump, and determining the target torque of the motor and the target flow of the oil pump based on the current speed, the current oil temperature and the optimal loss calibration file; in this way, after calibrating the energy consumption of the whole vehicle under different motor speeds, oil temperatures, oil pump flows and torque combinations, during the driving of the vehicle, the motor torque corresponding to the minimum energy consumption of the whole vehicle can be found according to the current speed of the motor and the current oil temperature of the oil pump. Compared with the direct zeroing operation of the motor torque, the energy consumption of the whole vehicle can be further reduced and the vehicle endurance can be improved.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a method, device and vehicle for reducing energy consumption of a whole vehicle. Background Art

[0002] An oil-cooled permanent magnet synchronous motor uses permanent magnets as its rotor and dissipates heat through oil cooling. Drag loss refers to the energy lost during motor operation due to non-ideal factors such as bearing preload, friction loss from oil seals, and churning loss caused by oil circulation.

[0003] Generally speaking, a vehicle contains two oil-cooled permanent magnet synchronous motors. For driving scenarios with low torque conditions (such as urban conditions), in order to reduce drag loss and thus reduce the energy consumption of the entire vehicle, when the vehicle implements a torque distribution strategy, it usually controls one motor to work and controls the other motor to output zero torque (unit: Nm).

[0004] However, since the wheel-end mechanical loss of the vehicle, the DC loss of the microcontroller unit (MCU) bus, and the total power loss of the oil pump lubrication are not linearly related to the output torque of the motor, even if the motor has zero torque output at this time, it cannot ensure that the energy consumption of the entire vehicle is the lowest, which in turn affects the vehicle's endurance. Summary of the Invention

[0005] In response to the problems existing in the prior art, the embodiments of the present invention provide a method, device and vehicle for reducing the energy consumption of the entire vehicle, so as to solve or partially solve the technical problem that the prior art cannot effectively reduce the energy consumption of the entire vehicle, thereby affecting the vehicle's endurance.

[0006] A first aspect of the present invention provides a method for reducing energy consumption of a vehicle, the method comprising:

[0007] Determining a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump operating loss of the vehicle, and constructing a vehicle energy consumption objective function based on the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump operating loss;

[0008] Calibrate the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle according to the vehicle energy consumption objective function to obtain an optimal loss calibration file;

[0009] During the driving process of the vehicle, the current speed of the motor and the current oil temperature of the oil pump are obtained, and the target torque of the motor and the target flow of the oil pump are determined based on the current speed, the current oil temperature and the optimal loss calibration file; the target torque and the target flow are used to ensure that the output value of the vehicle energy consumption objective function is minimized.

[0010] In the above solution, determining the bus loss of the microcontroller of the vehicle includes:

[0011] Obtaining the three-phase current of the motor;

[0012] Determining the bus current of the microcontroller according to the three-phase current, a preset modulation ratio, a preset three-phase duty cycle, and a compensation factor;

[0013] The bus loss of the microcontroller is determined according to the bus current of the microcontroller, the bus voltage of the microcontroller and the electric control compensation loss.

[0014] In the above solution, determining the wheel end mechanical loss includes:

[0015] Performing Clarke transformation on the three-phase current of the motor to obtain direct-axis current and quadrature-axis current;

[0016] determining an output torque of the motor according to the direct-axis current, the quadrature-axis current, the number of pole pairs of the motor, the rotor flux of the motor, the direct-axis inductance and the quadrature-axis inductance of the motor;

[0017] Determine the total loss based on the load loss, no-load loss, bearing loss, seal loss and gear accessory loss of the reducer;

[0018] The wheel end mechanical loss is determined according to the total loss, a preset speed ratio of the reducer, the output torque, and the wheel end output speed.

[0019] In the above solution, determining the oil pump operating loss includes:

[0020] Obtaining the power supply voltage of the oil pump and the bus current of the oil pump;

[0021] The oil pump operating loss is determined according to the power supply voltage of the oil pump and the bus current of the oil pump; the oil pump operating loss is the product of the power supply voltage of the oil pump and the bus current of the oil pump.

[0022] In the above solution, the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle are calibrated according to the vehicle energy consumption objective function to obtain the optimal loss calibration file, including:

[0023] The motor to be tested and the oil pump to be tested are placed on a test bench, wherein the test bench is located in an environmental chamber with adjustable test temperature; the motor to be tested is the same model as the motor of the vehicle, and the oil pump to be tested is the same model as the oil pump of the vehicle;

[0024] Obtaining a speed range of the motor to be tested, a torque range of the motor to be tested, an oil temperature range of the oil pump to be tested, and a flow range of the oil pump to be tested;

[0025] Determining a plurality of speeds according to a speed range and a speed calibration step of the motor to be tested, determining a plurality of oil temperatures according to an oil temperature range and an oil temperature calibration step of the oil pump to be tested, and determining a plurality of speed and oil temperature combinations according to the plurality of speeds and the plurality of oil temperatures;

[0026] Determine multiple flow rates according to the flow range and flow calibration step of the oil pump to be tested, and determine multiple groups of speed, oil temperature and flow rate combinations according to multiple speed and oil temperature combinations and the multiple flow rates;

[0027] Under each combination of the speed, oil temperature, and flow rate, sequentially adjusting the output torque of the motor to be tested within the torque range of the motor to be tested according to a preset torque calibration step size, and determining the corresponding vehicle energy consumption based on each combination of the speed, oil temperature, flow rate, output torque and the vehicle energy consumption objective function;

[0028] Each combination of the rotational speed, oil temperature, flow rate, and output torque is associated with the corresponding vehicle energy consumption to obtain the optimal loss calibration file.

[0029] In the above solution, the maximum torque in the torque range of the motor to be tested is determined according to the wheel end torque, and the wheel end torque is less than or equal to zero.

[0030] In the above solution, determining the target torque of the motor and the target flow rate of the oil pump based on the current speed, the current oil temperature, and the optimal loss calibration file includes:

[0031] searching the corresponding motor torque and oil pump flow in the optimal loss calibration file based on the current speed and the current oil temperature;

[0032] The motor torque found is determined as the target torque, and the oil pump flow found is determined as the target flow.

[0033] A second aspect of the present invention provides a device for reducing energy consumption of a vehicle, the device comprising:

[0034] a first determining unit, configured to determine a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump operating loss of the vehicle, and construct an energy consumption objective function of the entire vehicle according to the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump operating loss;

[0035] a calibration unit, configured to calibrate the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle according to the vehicle energy consumption objective function to obtain an optimal loss calibration file;

[0036] The second determination unit is used to obtain the current speed of the motor and the current oil temperature of the oil pump during the driving of the vehicle, and determine the target torque of the motor and the target flow of the oil pump based on the current speed, the current oil temperature and the optimal loss calibration file; the target torque and the target flow are used to ensure that the output value of the vehicle energy consumption objective function is minimized.

[0037] In the above solution, the first determining unit is specifically configured to:

[0038] Obtaining the three-phase current of the motor;

[0039] Determining the bus current of the microcontroller according to the three-phase current, a preset modulation ratio, a preset three-phase duty cycle, and a compensation factor;

[0040] The bus loss of the microcontroller is determined according to the bus current of the microcontroller, the bus voltage of the microcontroller and the electric control compensation loss.

[0041] In the above solution, the first determining unit is specifically configured to:

[0042] Performing Clarke transformation on the three-phase current of the motor to obtain direct-axis current and quadrature-axis current;

[0043] determining an output torque of the motor according to the direct-axis current, the quadrature-axis current, the number of pole pairs of the motor, the rotor flux of the motor, the direct-axis inductance and the quadrature-axis inductance of the motor;

[0044] Determine the total loss based on the load loss, no-load loss, bearing loss, seal loss and gear accessory loss of the reducer;

[0045] The wheel end mechanical loss is determined according to the total loss, a preset speed ratio of the reducer, the output torque, and the wheel end output speed.

[0046] In the above solution, the first determining unit is specifically configured to:

[0047] Obtaining the power supply voltage of the oil pump and the bus current of the oil pump;

[0048] The oil pump operating loss is determined according to the power supply voltage of the oil pump and the bus current of the oil pump; the oil pump operating loss is the product of the power supply voltage of the oil pump and the bus current of the oil pump.

[0049] In the above solution, the calibration unit is specifically used to:

[0050] The motor to be tested and the oil pump to be tested are placed on a test bench, wherein the test bench is located in an environmental chamber with adjustable test temperature; the motor to be tested is the same model as the motor of the vehicle, and the oil pump to be tested is the same model as the oil pump of the vehicle;

[0051] Obtaining a speed range of the motor to be tested, a torque range of the motor to be tested, an oil temperature range of the oil pump to be tested, and a flow range of the oil pump to be tested;

[0052] Determining a plurality of speeds according to a speed range and a speed calibration step of the motor to be tested, determining a plurality of oil temperatures according to an oil temperature range and an oil temperature calibration step of the oil pump to be tested, and determining a plurality of speed and oil temperature combinations according to the plurality of speeds and the plurality of oil temperatures;

[0053] Determine multiple flow rates according to the flow range and flow calibration step of the oil pump to be tested, and determine multiple groups of speed, oil temperature and flow rate combinations according to multiple speed and oil temperature combinations and the multiple flow rates;

[0054] Under each combination of the speed, oil temperature, and flow rate, sequentially adjusting the output torque of the motor to be tested within the torque range of the motor to be tested according to a preset torque calibration step size, and determining the corresponding vehicle energy consumption based on each combination of the speed, oil temperature, flow rate, output torque and the vehicle energy consumption objective function;

[0055] Each combination of the rotational speed, oil temperature, flow rate, and output torque is associated with the corresponding vehicle energy consumption to obtain the optimal loss calibration file.

[0056] In the above solution, the maximum torque in the torque range of the motor to be tested is determined according to the wheel end torque, and the wheel end torque is less than or equal to zero.

[0057] In the above solution, the second determining unit is specifically configured to:

[0058] searching the corresponding motor torque and oil pump flow in the optimal loss calibration file based on the current speed and the current oil temperature;

[0059] The motor torque found is determined as the target torque, and the oil pump flow found is determined as the target flow.

[0060] According to a third aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps of any one of the methods described in the first aspect are implemented.

[0061] According to a fourth aspect of the present invention, a vehicle is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any one of the methods described in the first aspect are implemented.

[0062] The present invention provides a method, device, medium and vehicle for reducing the energy consumption of a whole vehicle, the method comprising: determining the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss of the vehicle, and constructing a whole vehicle energy consumption target function according to the microcontroller bus loss, the wheel-end mechanical loss and the oil pump working loss; calibrating the motor speed, oil temperature, motor torque and oil pump flow of the vehicle according to the whole vehicle energy consumption target function to obtain an optimal loss calibration file; during the driving of the vehicle, obtaining the current speed of the motor and the current oil temperature of the oil pump, and determining the target torque of the motor based on the current speed, the current oil temperature and the optimal loss calibration file. torque and the target flow of the oil pump; the target torque and the target flow are used to ensure that the output value of the energy consumption target function of the whole vehicle is minimized; in this way, the energy consumption target function of the whole vehicle is determined by the bus loss of the microcontroller, the mechanical loss of the wheel end and the working loss of the oil pump, and is calibrated from four dimensions of motor speed, oil temperature, oil pump flow and torque, so that the energy consumption of the whole vehicle under different motor speed, oil temperature, oil pump flow and torque combinations can be obtained; then in the actual driving process of the vehicle, the motor torque corresponding to the minimum energy consumption of the whole vehicle can be found according to the current speed of the motor and the current oil temperature of the oil pump. Compared with the direct zero operation of the motor torque, the energy consumption of the whole vehicle can be further reduced and the vehicle endurance can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0064] Figure 1 A schematic flow chart of a method for reducing vehicle energy consumption according to one embodiment of the present invention is shown;

[0065] Figure 2 shows a torque map generated during a calibration process according to one embodiment of the present invention;

[0066] Figure 3 FIG2 shows a schematic diagram of a partially enlarged torque map according to an embodiment of the present invention;

[0067] Figure 4 A schematic structural diagram of a device for reducing energy consumption of a vehicle according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0068] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0069] The present invention provides a method for reducing the energy consumption of a vehicle, such as Figure 1 As shown, the method includes the following steps:

[0070] S110, determining the microcontroller bus loss, wheel end mechanical loss and oil pump operating loss of the vehicle, and constructing a vehicle energy consumption target function based on the microcontroller bus loss, the wheel end mechanical loss and the oil pump operating loss.

[0071] The zero torque output of the oil-cooled synchronous motor simply controls the motor spline output to zero torque (0Nm) output. However, since the wheel-end mechanical loss, microcontroller unit (MCU) bus loss (MCU bus DC loss), and oil pump operating loss are not linearly related, even if the motor outputs zero torque at this time, it does not mean that the energy consumption of the entire vehicle is the lowest. Therefore, the present invention finds the relationship between the wheel-end mechanical loss, MCU bus DC loss, oil pump operating loss and the optimal output torque of the motor, so that the sum of the wheel-end mechanical loss, MCU bus DC loss, and oil pump operating loss can be minimized at a certain optimal torque, that is, the energy consumption of the entire vehicle is minimized, and the cruising range is further improved.

[0072] Specifically, when the vehicle controller controls the motor to output zero torque, the reducer will have 50Nm of mechanical drag, so the electric drive assembly will actually have 0-50Nm of drag. This drag is applied to the wheels during vehicle operation, increasing vehicle resistance. If the motor outputs a smaller forward drive torque (for example, 1Nm), this torque is not enough to overcome the 50Nm mechanical drag generated by the wheel end, but the mechanical drag at the wheel end is reduced, and the vehicle controller can accept it in this case.

[0073] When the output torque of the motor gradually increases to A (for example, A is 6 Nm), although the 50 Nm mechanical drag generated by the wheel end can be overcome, a positive driving wheel end torque also appears at the same time. In this case, the whole vehicle may experience unexpected acceleration, so this situation is not allowed by the whole vehicle controller. Therefore, the present invention needs to optimize the overall energy consumption of the vehicle within the torque range of (0 ~ ANm) and determine the most suitable motor output torque to minimize the energy consumption of the whole vehicle.

[0074] Since the energy consumption of the entire vehicle includes the microcontroller bus loss, wheel-end mechanical loss and oil pump operating loss, it is necessary to first determine the microcontroller bus loss, wheel-end mechanical loss and oil pump operating loss.

[0075] In one embodiment, determining a microcontroller bus loss of a vehicle includes:

[0076] Get the three-phase current of the motor;

[0077] determining a bus current of the microcontroller according to the three-phase current, a preset modulation ratio, a preset modified three-phase duty cycle, and a compensation factor;

[0078] The bus loss of the microcontroller is determined according to the bus current of the microcontroller, the bus voltage of the microcontroller and the electronic control compensation loss.

[0079] Specifically, the three-phase current of the motor can be collected by the current sensor, and then the bus current i of the microcontroller can be determined according to formula (1): 母线 :

[0080]

[0081] In formula (1), μ D is the compensation factor, M is the modulation ratio, i a is the phase A current, i b is the B phase current, i c is the C phase current, D a To correct the duty cycle of phase A, D b To correct the duty cycle of phase B, D c To correct the C phase duty cycle.

[0082] Then, the microcontroller bus loss P1 is determined according to formula (2):

[0083] P1=U d ×i 母线 +P0 (2)

[0084] In formula (2), U d is the bus voltage of the microcontroller, and P0 is the electronic control compensation loss.

[0085] In one embodiment, determining wheel end mechanical losses includes:

[0086] Perform Clark transformation on the three-phase current of the motor to obtain the direct-axis current and quadrature-axis current;

[0087] The output torque of the motor is determined according to the direct-axis current, the quadrature-axis current, the number of pole pairs of the motor, the rotor flux of the motor, the direct-axis inductance and the quadrature-axis inductance of the motor;

[0088] Determine the total loss based on the load loss, no-load loss, bearing loss, seal loss and gear accessory loss of the reducer;

[0089] The wheel end mechanical loss is determined based on the total loss, the preset speed ratio of the reducer, the output torque, and the wheel end output speed.

[0090] Specifically, after obtaining the three-phase current of the motor, the three-phase AC current can be converted from the three-phase stationary coordinate system to the orthogonal rotating coordinate system according to Clark transformation to obtain two orthogonal currents i a ′ and i β Then, according to formula (3), the two orthogonal currents are transformed by Park to obtain the direct axis current i d and the quadrature axis current i q :

[0091]

[0092] In formula (3), θ is the rotor position angle.

[0093] Direct axis current i d and the quadrature axis current i q After determining, the output torque T of the motor can be determined according to formula (4):

[0094] T=1.5×p×(ψ f ×i q +(L d -L q )×i d ×i q ) (4)

[0095] In formula (4), p is the number of motor pole pairs, ψ f is the rotor flux, L d is the direct-axis inductance, L q is the quadrature-axis inductance.

[0096] The total loss of the reducer includes load loss, no-load loss, bearing loss, seal loss and gear accessory loss. The total loss of the reducer P v It can be determined according to formula (5):

[0097] P v =P vo +P vz +P w +P mo +P vx (5)

[0098] In formula (5), P vo is the reducer load loss, P vz is the no-load loss, P wis the bearing loss, P mo is the seal loss, P vx Gear accessory loss.

[0099] Among them, the reducer load loss and the seal load loss are strongly correlated with the motor output torque determined above, that is, P vo +P w ∝f[T,i]; no-load loss is strongly related to the oil pump flow and oil temperature, that is, P vz ∝f[q,T 油 ,i];T 油 is the oil temperature, q is the oil pump flow rate, and i is other unknown parameters that may affect the loss.

[0100] Then the final wheel end mechanical loss can be determined according to formula (6):

[0101]

[0102] In formula (6), P2 is the wheel end mechanical loss, n out is the wheel end output speed, T is the motor output torque, i g is the speed ratio of the reducer.

[0103] In one embodiment, determining the oil pump operating loss includes:

[0104] Obtaining the power supply voltage of the oil pump and the bus current of the oil pump;

[0105] The oil pump operating loss is determined based on the power supply voltage of the oil pump and the bus current of the oil pump; the oil pump operating loss is the product of the power supply voltage of the oil pump and the bus current of the oil pump.

[0106] The oil pump working loss P3 can be determined according to formula (7):

[0107] P3=U dc ×I dc (7)

[0108] In formula (7), U dc The power supply voltage of the oil pump is a low-voltage power supply with a value range of 12 to 14V; I dc is the bus current of the oil pump.

[0109] Among them, the oil pump loss is strongly related to the flow rate and oil temperature of the lubricating oil. The flow rate and oil temperature of the lubricating oil will affect the oil pump loss. At the same time, the flow rate of the lubricating oil directly affects the lubrication state and can also change the reducer loss. For example, the greater the flow rate of the oil pump, the greater the no-load loss P vz The smaller the reducer loss is, the smaller the

[0110] After the microcontroller bus loss, wheel-end mechanical loss, and oil pump working loss of the above vehicle are determined, the vehicle energy consumption objective function can be constructed according to formula (8):

[0111] Z=P1+P2+P3 (8)

[0112] Substituting the above-determined P1, P2, and P3 into formula (8) yields the final vehicle energy consumption objective function:

[0113]

[0114] It can be seen from formula (9) that the output torque of the motor can directly affect the bus loss of the microcontroller and can also compensate for the original drag loss of the reducer. The oil temperature and flow rate have a direct impact on the oil loss of the reducer, and the various variables are coupled with each other and are nonlinear. Therefore, it cannot be simply assumed that the energy consumption of the entire vehicle is the lowest when the motor output torque is 0.

[0115] S111 , calibrating the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle according to the vehicle energy consumption objective function to obtain an optimal loss calibration file.

[0116] In order to determine the optimal motor output torque and minimize the energy consumption of the entire vehicle, the present invention needs to calibrate the vehicle's motor speed, oil temperature, motor torque and oil pump flow according to the vehicle's energy consumption objective function to obtain the optimal loss calibration file.

[0117] In one embodiment, the vehicle's motor speed, oil temperature, motor torque, and oil pump flow are calibrated according to the vehicle's energy consumption objective function to obtain an optimal loss calibration file, including:

[0118] Place the motor to be tested and the oil pump to be tested on a test bench, which is located in an environmental chamber with adjustable test temperature. The motor to be tested must be the same model as the vehicle's motor, and the oil pump to be tested must be the same model as the vehicle's oil pump.

[0119] Obtain the speed range of the motor to be tested, the torque range of the motor to be tested, the oil temperature range of the oil pump to be tested, and the flow range of the oil pump to be tested;

[0120] Determine multiple speeds based on the speed range and speed calibration step of the motor to be tested, determine multiple oil temperatures based on the oil temperature range and oil temperature calibration step of the oil pump to be tested, and determine multiple speed and oil temperature combinations based on the multiple speeds and multiple oil temperatures;

[0121] Determine multiple flow rates based on the flow range and flow calibration step of the oil pump to be tested, and determine multiple speed, oil temperature and flow rate combinations based on multiple speed and oil temperature combinations and multiple flow rates;

[0122] Under each combination of speed, oil temperature, and flow rate, the output torque of the motor to be tested is adjusted sequentially within the torque range of the motor to be tested according to a preset torque calibration step size, and the corresponding vehicle energy consumption is determined based on each combination of speed, oil temperature, flow rate, output torque, and the vehicle energy consumption objective function;

[0123] Each combination of speed, oil temperature, flow rate, and output torque is associated with the corresponding vehicle energy consumption to obtain the optimal loss calibration file.

[0124] The maximum torque within the torque range of the motor under test is determined by the wheel-end torque, which is less than or equal to zero. This means that when the motor under test is outputting maximum torque, the wheel-end torque cannot exceed zero in the positive direction to prevent unintended vehicle acceleration.

[0125] Specifically, the calibration steps are as follows:

[0126] S1, prepare the experimental bench and environmental chamber. The experimental bench is a 3-input and 1-output (3 input ports and 1 output port) assembly bench.

[0127] S2, adjust the temperature of the environmental chamber so that the oil temperature range is -40℃-85℃; the MCU bus needs to be equipped with a power analyzer; the oil pump low-voltage power supply needs to be equipped with a separate low-voltage regulated power supply to monitor the oil pump power; the oil temperature calibration step is 5℃ or 10℃.

[0128] S3, set the speed range of the motor to be tested; generally speaking, the motor speed range is 0-20000rpm, then the speed range (calibration range) can be determined to be 0-120000rpm, and the speed calibration step is 500rpm or 1000rpm, which can be set according to actual needs.

[0129] S4: Set the torque range of the motor to be tested to 0~A. The value of A must ensure that the wheel end torque cannot be greater than 0 in the positive direction. The torque calibration step can be 1Nm.

[0130] S5, set the flow range of the oil pump. The flow of the oil pump is adjusted by the speed of the oil pump. Here the flow range is set to 0~n max , n max It can be determined according to the oil pump model. The flow rate calibration step can be 1L / min.

[0131] Therein, step S4 and step S5 may be performed in any order.

[0132] In the actual calibration process, the speed and oil temperature are taken as fixed quantities, and the oil pump flow and motor torque are adjusted respectively to obtain multiple combinations of speed, oil temperature, flow and torque. Each combination of speed, oil temperature, flow and torque is traversed to calibrate its energy consumption. Each set of speed, oil temperature, flow and torque is substituted into the above formula (9) to obtain the corresponding vehicle energy consumption. Finally, a calibration data table (map) can be generated, which is the optimal loss calibration file.

[0133] Specifically, since the present invention involves multi-parameter calibration, the motor speed and oil pump temperature, two variables that follow the vehicle's operating state, are incorporated into the calibration process to calibrate the optimal loss calibration file for all operating conditions. In other words, during calibration, the present invention focuses on adjusting the motor torque and oil pump flow under a certain combination of speed and oil temperature to obtain a set of parameter combinations. This set of parameters is then substituted into the above formula (9) to obtain the corresponding vehicle energy consumption.

[0134] Then, during calibration, multiple speeds can be divided according to the speed range and the speed calibration step, and multiple oil temperatures can be divided according to the oil temperature range and the oil temperature calibration step; the speeds and oil temperatures are combined respectively to obtain all speed and oil temperature parameter combinations.

[0135] For motor torque and oil pump flow, it is also necessary to divide multiple output torques according to the motor torque range and torque calibration step, and divide multiple flow rates according to the oil pump flow range and flow calibration step. Since motor torque has a greater impact on vehicle energy consumption, while oil pump flow has a smaller impact on vehicle energy consumption, during calibration, the flow rate can be fixed first to form a parameter combination of speed, oil temperature, and flow rate. Then, different output torques are tested in sequence at each speed, oil temperature, and flow rate parameter combination to obtain the corresponding vehicle energy consumption for each speed, oil temperature, flow rate, and torque parameter combination. This cycle is repeated until all speed, oil temperature, flow rate, and torque parameter combinations are tested to obtain the corresponding vehicle energy consumption.

[0136] Taking the vehicle environment with a motor speed of 2000rpm and an oil temperature of 20℃ as an example, the motor torque range is (0, 10Nm), and the oil pump flow range corresponding to the oil pump flow range is (0, 10L / min). When calibrating all parameter combinations of speed, oil temperature, flow and torque, it is found that the overall energy consumption first decreases when the motor has a small torque, and then suddenly increases as the torque increases to 5Nm. At the same time, the oil pump working flow also has an impact on the overall energy consumption, but the impact is small. Among them, the torque map generated during the calibration process is as follows: Figure 2 shown.

[0137] Will Figure 2 Amplify to get Figure 3 ,from Figure 3 It can be seen that when the energy consumption of the whole vehicle is the lowest, the corresponding motor torque is 1~1.5Nm, the corresponding oil pump flow is 2~4L / min, and the overall energy consumption is 634W. Compared with the overall energy consumption of 750W generated by directly outputting the motor to 0Nm in the existing technology, the overall energy consumption is reduced by 116W.

[0138] That is to say, for a vehicle with a motor of 2000rpm and an oil temperature of 20°C, the optimal output torque should be 1-1.5Nm (for example, the average value can be 1.25Nm), and the optimal oil pump flow should be 2-4L / min (for example, the average value can be 3L / min).

[0139] Following the same method, the overall energy consumption under all combinations of speed, oil temperature, torque and flow parameters can be calibrated to obtain the optimal loss calibration file.

[0140] S112, during the driving process of the vehicle, the current speed of the motor and the current oil temperature of the oil pump are obtained, and the target torque of the motor and the target flow of the oil pump are determined based on the current speed, the current oil temperature and the optimal loss calibration file; the target torque and the target flow are used to ensure that the output value of the vehicle energy consumption objective function is minimized.

[0141] During the actual driving process of the vehicle, if in a low-torque scenario, the current speed of the motor and the current oil temperature of the oil pump can be obtained. Based on the current speed, current oil temperature and the optimal loss calibration file, the target torque of the motor and the target flow of the oil pump are determined; the target torque and target flow are used to ensure that the output value of the vehicle's energy consumption objective function is minimized.

[0142] In one embodiment, determining the target torque of the motor and the target flow rate of the oil pump based on the current speed, the current oil temperature, and the optimal loss calibration file includes:

[0143] Based on the current speed and current oil temperature, the corresponding motor torque and oil pump flow are found in the optimal loss calibration file;

[0144] The motor torque found is determined as the target torque, and the oil pump flow found is determined as the target flow.

[0145] Continuing with the above example, if the current speed of the motor is 2000 rpm and the current oil temperature of the oil pump is 20°C, then the corresponding target torque can be found in the optimal loss calibration file as 1.25 Nm and the corresponding target flow rate is 3 L / min.

[0146] The energy consumption target function of the whole vehicle is determined by the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss, and calibrated from four dimensions: motor speed, oil temperature, oil pump flow and torque, so as to obtain the energy consumption of the whole vehicle under different combinations of motor speed, oil temperature, oil pump flow and torque; then, during the actual driving of the vehicle, the motor torque corresponding to the minimum energy consumption of the whole vehicle can be found according to the current speed of the motor and the current oil temperature of the oil pump. Compared with directly setting the motor torque to zero, the energy consumption of the whole vehicle can be further reduced and the vehicle endurance can be improved.

[0147] Based on the same inventive concept as in the above embodiment, this embodiment also provides a device for reducing the energy consumption of the entire vehicle, such as Figure 4 As shown, the device includes:

[0148] The first determining unit 41 is configured to determine a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump operating loss of the vehicle, and construct an energy consumption objective function of the vehicle based on the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump operating loss;

[0149] a calibration unit 42 for calibrating the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle according to the vehicle energy consumption objective function to obtain an optimal loss calibration file;

[0150] The second determination unit 43 is used to obtain the current speed of the motor and the current oil temperature of the oil pump during the driving of the vehicle, and determine the target torque of the motor and the target flow of the oil pump based on the current speed, the current oil temperature and the optimal loss calibration file; the target torque and the target flow are used to ensure that the output value of the vehicle energy consumption objective function is minimized.

[0151] Since the device described in the embodiments of the present invention is used to implement the method for reducing vehicle energy consumption according to the embodiments of the present invention, the specific structure and variations of the device are readily understood by those skilled in the art based on the methods described in the embodiments of the present invention, and therefore, no further description is given here. All devices used in the methods according to the embodiments of the present invention fall within the scope of protection of the present invention.

[0152] Based on the same inventive concept, this embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0153] Based on the same inventive concept, this embodiment provides a vehicle, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of any of the methods described above are implemented.

[0154] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages:

[0155] The present invention provides a method, device, medium and vehicle for reducing the energy consumption of a whole vehicle, the method comprising: determining the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss of the vehicle, and constructing a whole vehicle energy consumption target function according to the microcontroller bus loss, the wheel-end mechanical loss and the oil pump working loss; calibrating the motor speed, oil temperature, motor torque and oil pump flow of the vehicle according to the whole vehicle energy consumption target function to obtain an optimal loss calibration file; during the driving of the vehicle, obtaining the current speed of the motor and the current oil temperature of the oil pump, and determining the target torque of the motor based on the current speed, the current oil temperature and the optimal loss calibration file. torque and the target flow of the oil pump; the target torque and the target flow are used to ensure that the output value of the energy consumption target function of the whole vehicle is minimized; in this way, the energy consumption target function of the whole vehicle is determined by the bus loss of the microcontroller, the mechanical loss of the wheel end and the working loss of the oil pump, and is calibrated from four dimensions of motor speed, oil temperature, oil pump flow and torque, so that the energy consumption of the whole vehicle under different motor speed, oil temperature, oil pump flow and torque combinations can be obtained; then in the actual driving process of the vehicle, the motor torque corresponding to the minimum energy consumption of the whole vehicle can be found according to the current speed of the motor and the current oil temperature of the oil pump. Compared with the direct zero operation of the motor torque, the energy consumption of the whole vehicle can be further reduced and the vehicle endurance can be improved.

[0156] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0157] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for reducing vehicle energy consumption, characterized in that: The method comprises: Determining a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump operating loss of the vehicle, and constructing a vehicle energy consumption objective function based on the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump operating loss; Calibrate the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle according to the vehicle energy consumption objective function to obtain an optimal loss calibration file; During the driving process of the vehicle, the current speed of the motor and the current oil temperature of the oil pump are obtained, and the target torque of the motor and the target flow of the oil pump are determined based on the current speed, the current oil temperature and the optimal loss calibration file; the target torque and the target flow are used to ensure that the output value of the vehicle energy consumption objective function is minimized.

2. The method according to claim 1, wherein The determining of the microcontroller bus loss of the vehicle includes: Obtaining the three-phase current of the motor; Determining the bus current of the microcontroller according to the three-phase current, a preset modulation ratio, a preset three-phase duty cycle, and a compensation factor; The bus loss of the microcontroller is determined according to the bus current of the microcontroller, the bus voltage of the microcontroller and the electric control compensation loss.

3. The method according to claim 2, wherein The determining of wheel end mechanical loss includes: Performing Clarke transformation on the three-phase current of the motor to obtain direct-axis current and quadrature-axis current; determining an output torque of the motor according to the direct-axis current, the quadrature-axis current, the number of pole pairs of the motor, the rotor flux of the motor, the direct-axis inductance and the quadrature-axis inductance of the motor; Determine the total loss based on the load loss, no-load loss, bearing loss, seal loss and gear accessory loss of the reducer; The wheel end mechanical loss is determined according to the total loss, a preset speed ratio of the reducer, the output torque, and the wheel end output speed.

4. The method according to claim 1, wherein Determining the oil pump operating loss includes: Obtaining the power supply voltage of the oil pump and the bus current of the oil pump; The oil pump operating loss is determined according to the power supply voltage of the oil pump and the bus current of the oil pump; the oil pump operating loss is the product of the power supply voltage of the oil pump and the bus current of the oil pump.

5. The method according to claim 1, wherein The motor speed, oil temperature, motor torque, and oil pump flow of the vehicle are calibrated according to the vehicle energy consumption objective function to obtain an optimal loss calibration file, including: The motor to be tested and the oil pump to be tested are placed on a test bench, wherein the test bench is located in an environmental chamber with adjustable test temperature; the motor to be tested is the same model as the motor of the vehicle, and the oil pump to be tested is the same model as the oil pump of the vehicle; Obtaining a speed range of the motor to be tested, a torque range of the motor to be tested, an oil temperature range of the oil pump to be tested, and a flow range of the oil pump to be tested; Determining a plurality of speeds according to a speed range and a speed calibration step of the motor to be tested, determining a plurality of oil temperatures according to an oil temperature range and an oil temperature calibration step of the oil pump to be tested, and determining a plurality of speed and oil temperature combinations according to the plurality of speeds and the plurality of oil temperatures; Determine multiple flow rates according to the flow range and flow calibration step of the oil pump to be tested, and determine multiple groups of speed, oil temperature and flow rate combinations according to multiple speed and oil temperature combinations and the multiple flow rates; Under each combination of the speed, oil temperature, and flow rate, sequentially adjusting the output torque of the motor to be tested within the torque range of the motor to be tested according to a preset torque calibration step size, and determining the corresponding vehicle energy consumption based on each combination of the speed, oil temperature, flow rate, output torque and the vehicle energy consumption objective function; Each combination of the rotational speed, oil temperature, flow rate, and output torque is associated with the corresponding vehicle energy consumption to obtain the optimal loss calibration file.

6. The method according to claim 5, wherein The maximum torque in the torque range of the motor to be tested is determined according to the wheel end torque, and the wheel end torque is less than or equal to zero.

7. The method according to claim 1, wherein The determining the target torque of the motor and the target flow of the oil pump based on the current speed, the current oil temperature, and the optimal loss calibration file includes: searching the corresponding motor torque and oil pump flow in the optimal loss calibration file based on the current speed and the current oil temperature; The motor torque found is determined as the target torque, and the oil pump flow found is determined as the target flow.

8. A device for reducing energy consumption of a vehicle, characterized in that: The device comprises: a first determining unit, configured to determine a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump operating loss of the vehicle, and construct an energy consumption objective function of the entire vehicle according to the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump operating loss; a calibration unit, configured to calibrate the motor speed, oil temperature, motor torque, and oil pump flow of the vehicle according to the vehicle energy consumption objective function to obtain an optimal loss calibration file; The second determination unit is used to obtain the current speed of the motor and the current oil temperature of the oil pump during the driving of the vehicle, and determine the target torque of the motor and the target flow of the oil pump based on the current speed, the current oil temperature and the optimal loss calibration file; the target torque and the target flow are used to ensure that the output value of the vehicle energy consumption objective function is minimized.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method according to any one of claims 1 to 7 are implemented.

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