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

Abstract

The invention provides a method and a device for reducing the energy consumption of a whole vehicle, a medium and a vehicle. The method comprises the following steps: constructing a whole vehicle energy consumption objective function according to the bus loss of a microcontroller, the mechanical loss of a wheel end and the working loss of an oil pump; the motor rotating speed, the oil temperature, the motor torque and the oil pump flow of the vehicle are calibrated according to the whole vehicle energy consumption target function, and an optimal loss calibration file is obtained; in the running process of the vehicle, the current rotating 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 rotating speed, the current oil temperature and the optimal loss calibration file; thus, after the whole vehicle energy consumption under different motor rotating speed, oil temperature, oil pump flow and torque combinations is calibrated, the corresponding motor torque when the whole vehicle energy consumption is minimum can be found according to the current rotating speed of the motor and the current oil temperature of the oil pump in the vehicle driving process, compared with direct zero setting operation of the motor torque, the whole vehicle energy consumption can be further reduced, and the vehicle driving efficiency is improved. And the cruising ability of the vehicle is improved.

Description

Technical Field

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

[0002] An oil-cooled permanent magnet synchronous motor is a motor that uses permanent magnets as rotors and dissipates heat through oil cooling. Drag loss refers to the energy loss caused by non-ideal factors (such as bearing preload, oil seal friction loss, and oil churning loss caused by oil circulation) during the operation of the motor.

[0003] Generally speaking, a vehicle contains two oil-cooled permanent magnet synchronous motors. For driving scenarios with small torque conditions (such as urban conditions), in order to reduce drag losses 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 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 whole vehicle, so as to solve or partially solve the technical problem that the prior art cannot effectively reduce the energy consumption of the whole 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] Determine the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss of the vehicle, and construct a vehicle energy consumption objective function according to the microcontroller bus loss, the wheel-end mechanical loss and the oil pump working 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 whole vehicle energy consumption objective function is minimized.

[0010] In the above solution, the determining of 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, the determining of 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 the 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 according to 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 scheme, the determination of the oil pump working 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 value of the power supply voltage of the oil pump and the bus current of the oil pump.

[0022] In the above scheme, 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, and the test bench is located in an environmental chamber where the test temperature can be adjusted; the motor to be tested is consistent with the motor model of the vehicle, and the oil pump to be tested is consistent with the oil pump model of the vehicle;

[0024] Acquire 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;

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

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

[0027] Under each combination of the rotational speed, oil temperature and flow rate, the output torque of the motor to be tested is adjusted in sequence within the torque range of the motor to be tested according to a preset torque calibration step, and the corresponding vehicle energy consumption is determined based on each combination of the rotational 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, the target torque of the motor and the target flow rate of the oil pump are determined based on the current speed, the current oil temperature and the optimal loss calibration file, including:

[0031] Searching for 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 determination unit is used to determine a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump working loss of the vehicle, and to construct a vehicle energy consumption target function according to the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump working loss;

[0035] A calibration unit, used 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 whole vehicle energy consumption objective function is minimized.

[0037] In the above solution, the first determining unit is specifically used for:

[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 used for:

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

[0043] Determining the 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 according to 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 used for:

[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 value of the power supply voltage of the oil pump and the bus current of the oil pump.

[0049] In the above scheme, the calibration unit is specifically used for:

[0050] The motor to be tested and the oil pump to be tested are placed on a test bench, and the test bench is located in an environmental chamber where the test temperature can be adjusted; the motor to be tested is consistent with the motor model of the vehicle, and the oil pump to be tested is consistent with the oil pump model of the vehicle;

[0051] Acquire 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;

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

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

[0054] Under each combination of the rotational speed, oil temperature and flow rate, the output torque of the motor to be tested is adjusted in sequence within the torque range of the motor to be tested according to a preset torque calibration step, and the corresponding vehicle energy consumption is determined based on each combination of the rotational 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 used for:

[0058] Searching for 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 the processor implements the steps of any one of the methods described in the first aspect when executing the program.

[0062] The present invention provides a method, device, medium and vehicle for reducing the energy consumption of a whole vehicle. The method comprises: 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 process 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 whole vehicle energy consumption target function is minimized; in this way, the whole vehicle energy consumption target function is determined by the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss, and is calibrated from four dimensions: motor speed, oil temperature, oil pump flow and torque, so that the whole vehicle energy consumption under different motor speeds, oil temperatures, oil pump flows 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 zeroing 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 of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

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

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

[0066] Figure 3 A schematic diagram showing a partially enlarged torque map according to an embodiment of the present invention is shown;

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

[0068] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the 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. On the contrary, 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 comprises the following steps:

[0070] S110, 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.

[0071] The zero torque output of the oil-cooled synchronous motor simply controls the motor spline output to zero torque (0Nm) output, but since the wheel-end mechanical loss, microcontroller (MCU, Microcontroller Unit) bus loss (MCU bus DC loss), and oil pump working loss are not linear relationships, even if the motor has 0 torque output at this time, it does not mean that the energy consumption of the whole vehicle is the lowest. Therefore, the present invention seeks the relationship between the wheel-end mechanical loss, the MCU bus DC loss, the oil pump working loss and the optimal output torque of the motor, so that the sum of the wheel-end mechanical loss, the MCU bus DC loss, and the oil pump working loss can be minimized under a certain optimal torque, that is, the energy consumption of the whole 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 a mechanical drag of 50Nm, so the electric drive assembly will actually have a drag of 0-50Nm. This drag is applied to the wheels during vehicle operation, increasing vehicle resistance. If the motor outputs a smaller forward drive torque (such as 1Nm) at this time, although this torque is not enough to overcome the 50Nm mechanical drag generated by the wheel end, the mechanical drag at the wheel end becomes smaller, and the vehicle controller is acceptable at this time.

[0073] When the output torque of the motor gradually increases to A (for example, A is 6Nm), although the 50Nm 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 vehicle controller. Therefore, the present invention needs to optimize the overall energy consumption of the vehicle within the torque range of (0~ANm) to determine the most suitable motor output torque to minimize the energy consumption of the whole vehicle.

[0074] Since the energy consumption of the whole vehicle includes the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss, it is necessary to first determine the microcontroller bus loss, wheel-end mechanical loss and oil pump working 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 a 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 electric 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] The three-phase current of the motor is subjected to Clark transformation to obtain the direct-axis current and the 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 losses are determined based on the total losses, 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 the 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, 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 implementation, 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 working loss of the oil pump is determined according to the power supply voltage of the oil pump and the bus current of the oil pump; the working loss of the oil pump is the product value 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 is the power supply voltage of the oil pump, which 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, and both 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 larger the flow rate of the oil pump, the greater the no-load loss P vz The smaller the reducer loss, 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) can obtain 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 and nonlinear. Therefore, it cannot be simply assumed that the energy consumption of the whole 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 whole 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 whole 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 implementation, 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:

[0118] The motor to be tested and the oil pump to be tested are placed on a test bench, which is located in an environmental chamber where the test temperature can be adjusted; the motor to be tested is consistent with the motor model of the vehicle, and the oil pump to be tested is consistent with the oil pump model of the vehicle;

[0119] Obtaining 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 according to the speed range and speed calibration step of the motor to be tested, determine multiple oil temperatures according to the oil temperature range and oil temperature calibration step of the oil pump to be tested, and determine multiple speed and oil temperature combinations according to the multiple speeds and the multiple oil temperatures;

[0121] Determine multiple flow rates according to the flow range of the oil pump to be tested and the flow calibration step, and determine multiple groups of speed, oil temperature and flow rate combinations according to 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 in sequence within the torque range of the motor to be tested according to the 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 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. That is, when the motor to be tested outputs the maximum torque, the wheel end torque cannot have a positive torque greater than 0, so as to avoid unexpected acceleration of the vehicle.

[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 busbar of the MCU 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 as 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, and the A value 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 calibration step can be 1L / min.

[0131] Among them, 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 combination 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 is a multi-parameter calibration, the two variables of the motor speed and the oil temperature of the oil pump follow the running state of the whole vehicle. These two parameters are included in the calibration process in order to calibrate the optimal loss calibration file for all working conditions. That is, during calibration, the present invention actually focuses on a set of parameter combinations obtained by adjusting the two variables of motor torque and oil pump flow under a certain combination of speed and oil temperature, and then substitutes the set of parameters 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] As for the 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. The motor torque has a greater impact on the energy consumption of the whole vehicle, while the oil pump flow has a smaller impact on the energy consumption of the whole vehicle. Therefore, during calibration, the flow rate can be fixed first to form a parameter combination of speed, oil temperature and flow rate, and then different output torques are tested in turn at each speed, oil temperature and flow rate parameter combination to obtain the corresponding vehicle energy consumption under the 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 and the corresponding vehicle energy consumption is obtained.

[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 speed, oil temperature, flow and torque parameter combinations, 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 Zoom in 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 prior art, 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 whole vehicle energy consumption objective function is minimized.

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

[0142] In one implementation, 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:

[0143] Based on the current speed and current oil temperature, find the corresponding motor torque and oil pump flow 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 2000rpm 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 1.25Nm and the corresponding target flow rate is 3L / 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 is calibrated from four dimensions: motor speed, oil temperature, oil pump flow and torque, so that the energy consumption of the whole vehicle under different motor speeds, oil temperatures, oil pump flows and torque combinations can be obtained; 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's endurance can be improved.

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

[0148] A first determination unit 41 is used to determine the microcontroller bus loss, wheel end mechanical loss and oil pump working loss of the vehicle, and to construct a vehicle energy consumption target function according to the microcontroller bus loss, the wheel end mechanical loss and the oil pump working loss;

[0149] The calibration unit 42 is used 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;

[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 whole vehicle energy consumption objective function is minimized.

[0151] Since the device introduced in the embodiment of the present invention is a device used to implement the method for reducing the energy consumption of the whole vehicle in the embodiment of the present invention, based on the method introduced in the embodiment of the present invention, the person skilled in the art can understand the specific structure and deformation of the device, so it is not repeated here. All devices used in the method of the embodiment of the present invention belong to 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 methods described above 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, wherein the processor implements the steps of any of the methods described above when executing the program.

[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 comprises: 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 process 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 whole vehicle energy consumption target function is minimized; in this way, the whole vehicle energy consumption target function is determined by the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss, and is calibrated from four dimensions: motor speed, oil temperature, oil pump flow and torque, so that the whole vehicle energy consumption under different motor speeds, oil temperatures, oil pump flows 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 zeroing 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 other 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 protection scope 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 protection scope of the present invention.

Claims

1. A method for reducing vehicle energy consumption, characterized in that: The method comprises: Determine the microcontroller bus loss, wheel-end mechanical loss and oil pump working loss of the vehicle, and construct a vehicle energy consumption objective function according to the microcontroller bus loss, the wheel-end mechanical loss and the oil pump working 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 whole vehicle energy consumption objective function is minimized.

2. The method according to claim 1, characterized in that The determining of the microcontroller bus loss of the vehicle comprises: 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, characterized in that The determining of wheel end mechanical losses comprises: Performing Clarke transformation on the three-phase current of the motor to obtain direct-axis current and quadrature-axis current; Determining the 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 according to 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, characterized in that The determining of the oil pump working loss comprises: 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 value of the power supply voltage of the oil pump and the bus current of the oil pump.

5. The method according to claim 1, characterized in that 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, and the test bench is located in an environmental chamber where the test temperature can be adjusted; the motor to be tested is consistent with the motor model of the vehicle, and the oil pump to be tested is consistent with the oil pump model of the vehicle; Acquire 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; Determine a plurality of speeds according to a speed range and a speed calibration step of the motor to be tested, determine 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 determine a plurality of speed and oil temperature combinations according to the plurality of speeds and the plurality of oil temperatures; Determine a plurality of flow rates according to the flow range of the oil pump to be tested and the flow calibration step length, and determine a plurality of groups of speed, oil temperature and flow rate combinations according to a plurality of speed and oil temperature combinations and the plurality of flow rates; Under each combination of the rotational speed, oil temperature and flow rate, the output torque of the motor to be tested is adjusted in sequence within the torque range of the motor to be tested according to a preset torque calibration step, and the corresponding vehicle energy consumption is determined based on each combination of the rotational 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, characterized in that 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, characterized in that The 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: Searching for 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 the energy consumption of a vehicle, characterized in that: The device comprises: A first determination unit is used to determine a microcontroller bus loss, a wheel-end mechanical loss, and an oil pump working loss of the vehicle, and to construct a vehicle energy consumption target function according to the microcontroller bus loss, the wheel-end mechanical loss, and the oil pump working loss; A calibration unit, used 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 whole 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, characterized in that: 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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