Vehicle energy flow detection method and detection device

Abstract

The invention provides a vehicle energy flow detection method and device, and the method comprises the steps: determining the vehicle transmission resistance of a vehicle at a target vehicle speed and the internal resistance of a rotary drum test bench of a chassis dynamometer at the target vehicle speed; acquiring test data of the vehicle at the target vehicle speed, wherein the test data is data detected when the vehicle is at the target vehicle speed when a drive axle of the vehicle is placed on a drum corresponding to a chassis dynamometer; according to the test data of the vehicle at the target vehicle speed, the transmission resistance of the vehicle and the internal resistance of the chassis dynamometer, calculating the upper wheel end force and frictional resistance of the drum at the target vehicle speed; according to the test data at the target vehicle speed, the drum upper wheel end force and the friction resistance, the vehicle energy flow at the target vehicle speed is determined, and the vehicle energy flow is the efficiency and energy consumption conditions of all components in the vehicle power system energy transmission process. According to the invention, the accuracy of vehicle energy flow detection is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle energy flow testing. Specifically, it relates to a vehicle energy flow detection method and a detection device. Background Art

[0002] Currently, for the measurement process of commercial vehicles by chassis dynamometers, the existing technical solutions and their drawbacks are as follows:

[0003] (1) Some chassis dynamometers do not clearly distinguish between frictional resistance and vehicle transmission resistance during measurement, but rather consider the two together and collectively refer to them as "resistance". However, this method cannot accurately evaluate the power performance and energy consumption of the vehicle because the frictional resistance and vehicle transmission resistance may have significant differences in numerical values and also have different effects on vehicle performance.

[0004] (2) Some chassis dynamometers calculate the vehicle transmission resistance by estimating the efficiency of the transmission system. This method is based on certain assumptions and models, and calculates the vehicle transmission resistance by measuring the input power and the estimated transmission efficiency. However, the estimated transmission efficiency may not be accurate because the actual transmission efficiency may be affected by various factors (such as temperature, wear, lubrication conditions, etc.), resulting in errors in the calculation results.

[0005] (3) Disassemble each component of the vehicle's transmission system in sequence and measure the resistance of each component separately. This method requires disassembling the vehicle, which is complex and time-consuming, and moreover, the disassembly process may damage the integrity of the vehicle and affect subsequent use. In addition, new errors may be introduced during the disassembly and reassembly process. Summary of the Invention

[0006] In view of this, the purpose of the present application is to provide a vehicle energy flow detection method and a detection device to overcome at least one of the above defects.

[0007] In a first aspect, an embodiment of the present application provides a vehicle energy flow detection method, the method including: determining the vehicle transmission resistance of the vehicle at a target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed; obtaining the test data of the vehicle at the target vehicle speed, where the test data is the data detected when the drive axle of the vehicle is placed on the corresponding drum of the chassis dynamometer at the target vehicle speed; calculating the wheel end force and frictional resistance on the drum at the target vehicle speed according to the test data of the vehicle at the target vehicle speed, the vehicle transmission resistance, and the internal resistance of the chassis dynamometer; determining the vehicle energy flow at the target vehicle speed according to the test data of the vehicle at the target vehicle speed, the wheel end force on the drum, and the frictional resistance, where the vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle power system energy.

[0008] In an alternative embodiment of the present application, the vehicle transmission resistance at the target vehicle speed is determined in the following manner: when the vehicle is in the first test condition, the first acceleration without braking force at the target vehicle speed is detected when the vehicle is accelerated to the preset vehicle speed and then put into different gears to coast; when the vehicle is in the second test condition, the second acceleration with braking force at the target vehicle speed is detected when the vehicle is accelerated to the preset vehicle speed and then put into different gears to coast; based on the first acceleration and the second acceleration, the vehicle transmission resistance at the target vehicle speed is determined.

[0009] In an alternative embodiment of the present application, the first test condition is a condition in which the vehicle drive axle is jacked up to lift the drive wheels off the ground, the vehicle is accelerated to a predetermined speed and then put into different gears to start coasting, and the change in the first acceleration during the coasting process is measured. The second test condition is a condition in which the operation of the above first test condition is repeated, and a braking force is applied to the motor before the vehicle is accelerated, and the change in the second acceleration after the braking force is applied during the coasting process is measured.

[0010] In an alternative embodiment of the present application, the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed is determined in the following manner: when the drum test bench is in the third test condition, according to the operation manual of the chassis dynamometer, the drum coasting resistance coefficient at the target vehicle speed is fitted. The third test condition is that the drum is accelerated to the preset vehicle speed and then coasts at the vehicle speeds corresponding to different gears engaged by the vehicle; based on the drum coasting resistance coefficient at the target vehicle speed and the target vehicle speed, the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed is determined.

[0011] In an alternative embodiment of the present application, the wheel end force and frictional resistance on the drum at the target vehicle speed are calculated in the following manner: according to the vehicle force balance, it is determined that the sum of the rolling resistance and the air resistance is equal to the sum of the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor; based on the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor, the wheel end force on the drum at the target vehicle speed is determined; based on the drum coasting resistance coefficient, the force provided by the drum motor, the vehicle coasting resistance coefficient, and the vehicle transmission resistance, the frictional resistance at the target vehicle speed is determined.

[0012] In an optional embodiment of the present application, the test data includes vehicle battery output terminal current, battery output terminal voltage, motor controller input terminal current, motor controller input terminal current and voltage, motor controller output terminal current, motor controller output terminal voltage, motor speed and torque, wherein the vehicle energy flow includes battery terminal energy consumption, motor controller input energy consumption, motor controller output energy consumption, motor mechanical energy consumption, accessory energy consumption, vehicle transmission resistance loss, wheel end energy consumption and friction loss, wherein the vehicle energy flow at the target vehicle speed is determined by: calculating the battery terminal energy consumption according to the battery output terminal current at the target vehicle speed and the battery output terminal voltage at the target vehicle speed; The energy consumption of the motor controller input terminal is calculated according to the motor controller input terminal current at the target vehicle speed and the current and voltage at the motor controller input terminal at the target vehicle speed; the energy consumption of the motor controller output terminal is calculated according to the motor controller output terminal current at the target vehicle speed and the current and voltage at the motor controller output terminal at the target vehicle speed; the motor mechanical energy consumption is calculated according to the motor speed and torque at the target vehicle speed; the accessory energy consumption is calculated according to the battery terminal energy consumption at the target vehicle speed and the motor controller input terminal energy consumption at the target vehicle speed; the vehicle transmission resistance at different vehicle speeds, the wheel end force on the drum at different vehicle speeds and the friction resistance at different vehicle speeds are integrated over time to obtain the transmission loss, wheel end energy consumption and friction loss at each vehicle speed respectively.

[0013] In an optional embodiment of the present application, determining the vehicle transmission resistance based on the first acceleration and the second acceleration includes: constructing a first vehicle internal resistance equation based on the first acceleration, the equivalent moment of inertia and the mass of the vehicle; constructing a second vehicle internal resistance equation based on the second acceleration, the gearbox speed ratio, the final reducer speed ratio, the motor output force, the vehicle transmission resistance, the equivalent moment of inertia and the mass of the vehicle; and determining the vehicle transmission internal resistance by combining the first vehicle internal resistance equation and the second vehicle internal resistance equation.

[0014] In a second aspect, an embodiment of the present application further provides a vehicle energy flow detection device, the device comprising: a determination module, used to determine the vehicle transmission resistance of the vehicle at a target speed and the internal resistance of a drum test bench of a chassis dynamometer at the target speed; a test data acquisition module, used to acquire test data of the vehicle at the target speed, the test data being data detected when the vehicle is at the target speed when the drive axle of the vehicle is placed on the drum corresponding to the chassis dynamometer; a calculation module, used to calculate the wheel-end force and friction resistance on the drum at the target speed based on the test data of the vehicle at the target speed, the vehicle transmission resistance and the internal resistance of the chassis dynamometer; a vehicle energy flow determination module, used to determine the vehicle energy flow at the target speed based on the test data at the target speed, the wheel-end force on the drum and the friction resistance, the vehicle energy flow being the efficiency and energy consumption of each component of the vehicle power system during the energy transmission process.

[0015] In a third aspect, an embodiment of the present application further provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus. When the machine-readable instructions are executed by the processor, the steps of the method described above are performed.

[0016] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is run by a processor, the steps of the method described above are performed.

[0017] The vehicle energy flow detection method and detection device provided by the embodiments of the present application, wherein the method includes: determining the vehicle transmission resistance of the vehicle at a target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed; obtaining test data of the vehicle at the target vehicle speed, where the test data is the data detected when the drive axle of the vehicle is placed on the corresponding drum of the chassis dynamometer at the target vehicle speed; calculating the wheel end force and frictional resistance on the drum at the target vehicle speed according to the test data of the vehicle at the target vehicle speed, the vehicle transmission resistance, and the internal resistance of the chassis dynamometer; determining the vehicle energy flow at the target vehicle speed according to the test data of the vehicle at the target vehicle speed, the wheel end force on the drum, and the frictional resistance. The vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle power system energy. Through the present application, the accuracy of vehicle energy flow detection is improved.

[0018] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, details are described as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a flowchart of the vehicle energy flow detection method provided by the embodiments of the present application;

[0021] Figure 2 It is a flowchart of determining the vehicle transmission resistance of the vehicle at a target vehicle speed provided by the embodiments of the present application;

[0022] Figure 3 It is a flowchart of determining the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed provided by the embodiments of the present application;

[0023] Figure 4 Schematic diagram when performing energy flow detection for a vehicle;

[0024] Figure 5 Flowchart for determining the wheel end force and frictional resistance on a drum at a target vehicle speed provided by an embodiment of the present application;

[0025] Figure 6 Flowchart for determining the vehicle energy flow at a target vehicle speed provided by an embodiment of the present application;

[0026] Figure 7 Schematic diagram of the vehicle energy flow transmission path;

[0027] Figure 8 Schematic structural diagram of the vehicle energy flow detection device provided by an embodiment of the present application;

[0028] Figure 9 Schematic structural diagram of the electronic device provided by an embodiment of the present application. Detailed implementation manners

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, every other embodiment obtained by those skilled in the art without creative efforts belongs to the scope of protection of the present application.

[0030] First, the applicable application scenarios of the present application are introduced. The present application can be applied to the technical field of vehicle energy flow testing.

[0031] Through research, it is found that when a chassis dynamometer measures commercial vehicles at present, there are problems such as inaccurate evaluation due to not distinguishing frictional resistance and transmission resistance, errors in the calculation of estimated transmission efficiency, complex disassembly measurement operations, and possible damage to the vehicle integrity.

[0032] Based on this, the embodiments of the present application provide a vehicle energy flow detection method and a detection device, which involve determining the transmission resistance and the internal resistance of the drum of the chassis dynamometer at the target vehicle speed of a commercial vehicle. By collecting the test data of the vehicle under this condition and combining the known transmission resistance and the internal resistance of the chassis dynamometer, the wheel end force and the friction resistance on the drum are calculated. Further, these data are used to determine the energy flow of the vehicle's power system at the target vehicle speed, including the efficiency and energy consumption of each component.

[0033] Please refer to Figure 1 , Figure 1 which is the flowchart of the vehicle energy flow detection method provided by the embodiments of the present application. As Figure 1 shown in

[0034] S101. Determine the vehicle transmission resistance of the vehicle at the target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed.

[0035] Please refer to Figure 2 , Figure 2 which is the flowchart of determining the vehicle transmission resistance of the vehicle at the target vehicle speed provided by the embodiments of the present application.

[0036] Specifically, the vehicle transmission resistance of the vehicle at the target vehicle speed is determined by the following method:

[0037] S1011. When the vehicle is in the first test condition, detect the first acceleration without braking force at the target vehicle speed when the vehicle accelerates to the preset vehicle speed and then shifts into different gears and coasts.

[0038] Under the first test condition, the vehicle is placed on the chassis dynamometer, and its drive axle is lifted to lift the drive wheels off the ground to eliminate the influence of ground friction resistance.

[0039] The first test condition is a condition where the drive axle of the vehicle is lifted to lift the drive wheels off the ground, the vehicle is accelerated to a predetermined speed, then shifted into different gears and starts to coast, and the change of the first acceleration during the coasting process is measured.

[0040] The purpose of the first test condition is to accurately measure and evaluate the influence of the internal resistance of the vehicle transmission system on the vehicle's motion state without external braking force. This helps to accurately analyze the vehicle energy flow subsequently and optimize the design and performance of the vehicle transmission system.

[0041] The driver operates the vehicle to accelerate it to a preset vehicle speed, which is usually one of the one or more target vehicle speeds to be analyzed during the test process. Preferably, it can be 90 km / h.

[0042] After reaching the preset vehicle speed, the driver shifts the transmission into different gears and allows the vehicle to start coasting. At this time, the rotating components of the vehicle (such as the engine, drive shaft, wheels, etc.) will continue to rotate due to their own inertia, but will be affected by the internal resistance of the transmission system, resulting in a gradual decrease in speed.

[0043] During the coasting process, appropriate sensors and measuring devices are used to record the non-braking acceleration of the vehicle at the target vehicle speed (i.e., at a certain moment during the coasting process), which is the first acceleration. This acceleration reflects the influence of the internal resistance of the vehicle transmission system on the vehicle's motion state without the action of external braking force.

[0044] S1012. When the vehicle is in the second test condition, detect the second acceleration with braking force of the vehicle when it is coasting in different gears after accelerating to the preset vehicle speed and at the target vehicle speed;

[0045] The second test condition is similar to the first test condition, but at this time a small braking force is applied during the vehicle coasting process. This braking force can be achieved through the motor of the chassis dynamometer or applied to the vehicle in other ways.

[0046] The second test condition is to repeat the operation of the above first test condition, apply braking force to the motor before the vehicle accelerates, and measure the change of the second acceleration after applying the braking force during the coasting process.

[0047] The purpose of the second test condition is to further measure and evaluate the comprehensive influence of the internal resistance of the vehicle transmission system and the external braking force on the vehicle's motion state in the presence of external braking force. This helps to more comprehensively understand the energy flow characteristics of the vehicle during actual driving and provides more accurate data support for optimizing vehicle performance. At the same time, by comparing the test results of the first test condition and the second test condition, the influence degree of the braking force on the vehicle transmission resistance and energy flow can be further analyzed.

[0048] Same as the first test condition, the vehicle is first accelerated to the preset vehicle speed, then shifted into different gears and starts to coast. When coasting and applying the braking force, record the braking acceleration of the vehicle at the target vehicle speed, which is the second acceleration. This acceleration reflects the combined influence of the internal resistance of the vehicle transmission system and the braking force on the vehicle's motion state under the action of external braking force.

[0049] S1013. Determine the vehicle transmission resistance of the vehicle at the target vehicle speed according to the first acceleration and the second acceleration.

[0050] Construct the first vehicle internal resistance equation according to the first acceleration, equivalent moment of inertia and vehicle mass;

[0051] F r=δma1

[0052] Among them, F r is the vehicle transmission resistance, δ is the equivalent moment of inertia, m is the vehicle weight, and a1 is the first acceleration.

[0053] The equivalent moment of inertia is the sum of the moments of inertia of the rotating parts of the vehicle, which reflects the resistance of the rotating parts of the vehicle to rotation. This value can be obtained through theoretical calculation or experimental measurement.

[0054] The vehicle mass is the total weight of the vehicle, including the mass of all components such as the body, chassis, engine, transmission system, etc. This value can be directly measured by weighing equipment.

[0055] Construct a second vehicle internal resistance equation according to the second acceleration, the gearbox ratio, the final reducer ratio, the motor output force, the vehicle transmission resistance, the equivalent moment of inertia and the vehicle mass;

[0056] F t i g i0+F r =δma2

[0057] Among them, i g is the gearbox speed ratio, i0 is the main reducer speed ratio, F t is the motor output force, F r is the vehicle transmission resistance, δ is the equivalent moment of inertia, m is the vehicle weight, and a2 is the second acceleration.

[0058] Here, the gearbox ratio and the final reducer ratio are important parameters of the vehicle transmission system, which determine the transmission relationship between the motor output force and the wheels. These parameters can be obtained by consulting the vehicle technical documents or experimental measurements.

[0059] The motor output force is the product of the torque output by the motor under given working conditions and the speed. This value can be directly measured by the motor controller or sensor.

[0060] Using the first acceleration and the second acceleration, as well as known parameters such as the motor output force, gearbox ratio, final reducer ratio and vehicle mass, two dynamic equations are combined to solve the vehicle transmission resistance. These two equations reflect the motion state of the vehicle without braking force and with braking force respectively.

[0061] By solving these two equations, the vehicle transmission resistance at the target speed can be obtained. This resistance is a comprehensive reflection of various resistances within the vehicle transmission system (such as bearing friction, gear meshing resistance, etc.).

[0062] The first vehicle internal resistance equation and the second vehicle internal resistance equation are combined to determine the vehicle transmission internal resistance.

[0063] When the transmission is shifted into different gears and starts to coast, the rotating components of the vehicle (such as the engine, drive shaft, wheels, etc.) will indeed continue to rotate due to their own inertia. However, since the drive wheels have left the ground, the rotation of these rotating components will not cause the vehicle to move on the ground. Instead, they will be affected by the internal resistance of the transmission system, resulting in a gradual decrease in rotational speed. This process is mainly used to test or analyze the performance of the vehicle's transmission system, especially the vehicle transmission resistance and the inertia effect of the rotating components. By measuring the change in rotational speed during the coasting process, the magnitude of the transmission system resistance can be deduced, and then the power performance and energy consumption of the vehicle can be evaluated.

[0064] Please refer to Figure 3 , Figure 3 which is the flowchart for determining the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed provided by the embodiment of the present application.

[0065] Specifically, the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed is determined by the following method:

[0066] S201. When the drum test bench is in the third test condition, according to the chassis dynamometer operation manual, fit the drum coasting resistance coefficient at the target vehicle speed.

[0067] The third test condition is that the drum is accelerated to a preset vehicle speed and then coasts at the vehicle speeds corresponding to different gears engaged.

[0068] Under the third test condition, the drum test bench is operated independently without connecting to the actual vehicle. The drum is accelerated to a preset vehicle speed (this vehicle speed is usually matched with the target vehicle speed of the vehicle to be tested later), and then coasts at the vehicle speeds corresponding to different gears engaged. During this process, the drum will be affected by its own coasting resistance, resulting in a gradual decrease in rotational speed.

[0069] The chassis dynamometer operation manual is the instruction manual for the chassis dynamometer, which contains detailed information on how to operate, calibrate, and maintain the dynamometer. In this step, relevant chapters in the manual need to be referred to understand how to measure and record the key parameters during the drum coasting process.

[0070] During the drum coasting process, appropriate sensors and measuring devices are used to record the drum coasting data, including rotational speed and coasting distance at different time points, etc. Then, based on these data and the mathematical model or fitting method provided in the chassis dynamometer operation manual, the drum coasting resistance coefficient at the target vehicle speed is fitted. This coefficient reflects the magnitude of the resistance received by the drum during the coasting process and is a key parameter for calculating the internal resistance of the drum test bench later.

[0071] S202. Determine the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed based on the drum coast-down resistance coefficient at the target vehicle speed and the target vehicle speed.

[0072] Calculate the internal resistance of the drum test bench at the target vehicle speed through the following formula:

[0073] a′ + b′v + c′v 2 = F rc

[0074] where a′, b′, and c′ are all drum coast-down resistance coefficients, v is the target speed, and F rc is the internal resistance of the drum test bench at the target vehicle speed.

[0075] In step S201, the drum coast-down resistance coefficient at the target vehicle speed has been fitted. This coefficient is the basis for subsequent calculation of the internal resistance of the drum test bench.

[0076] In addition to the drum coast-down resistance coefficient, the specific vehicle speed value at the target vehicle speed is also required. This vehicle speed value is usually set according to the test requirements and aims to simulate various vehicle speed situations that the vehicle may encounter during actual driving.

[0077] According to the mathematical model or formula provided in the chassis dynamometer operation manual, substitute the fitted drum coast-down resistance coefficient and the target vehicle speed into the formula to calculate the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed. The internal resistance of the drum test bench reflects the resistance magnitude that the drum test bench receives during the simulation of vehicle driving and is an important indicator for evaluating the performance and accuracy of the dynamometer.

[0078] S102. Obtain the test data of the vehicle at the target vehicle speed.

[0079] The test data is the data detected when the drive axle of the vehicle is placed on the corresponding drum of the chassis dynamometer at the target vehicle speed.

[0080] Place the drive axle of the vehicle on the drum of the chassis dynamometer, with the front axle of the vehicle on the ground. For example, generally, a commercial vehicle chassis dynamometer uses a single large drum. Place the drive axle on the drum. Take a 6×4 tractor as an example (6×4 means the vehicle has 6 wheels, 4 of which are drive wheels, and there are two drive axles, with each drive axle responsible for driving two wheels).

[0081] Please refer to Figure 4 , Figure 4 for the schematic diagram when the energy flow of the vehicle is detected.

[0082] As Figure 4As shown in the figure, the vehicle 1 includes two drive axles 2 and a front axle 4. The two drive axles 2 are placed on the drum 3, and the front axle 4 is placed on the ground 5, and the vehicle maintains balance.

[0083] The current and voltage at the output terminal of the battery, the current and voltage at the input terminal of the motor controller, the current and voltage at the output terminal of the motor controller, and the vehicle power CAN message acquisition device.

[0084] Input the rolling resistance coefficients a, b, and c of the vehicle onto the test bench of the chassis dynamometer, and let the driver operate the vehicle according to the working conditions to be measured, collect data in real time, and conduct force analysis and derivation.

[0085] For example, the forces during coasting are the internal resistance of the vehicle transmission system, the rolling resistance of the vehicle, and the air resistance of the vehicle. At this time, the power loss analysis in the chassis dynamometer test is as follows:

[0086] P t = P r + P fc + P rc + P dy

[0087] Among them, P t is the mechanical power output by the motor, P r is the power loss due to vehicle transmission resistance, P fc is the power consumed by the rolling resistance generated by the driving tires and the drum, P rc is the power consumed by the internal resistance of the drum test bench, and P dy is the resistance power provided by the drum motor.

[0088] S103. Calculate the wheel end force and frictional resistance on the drum at the target vehicle speed based on the test data of the vehicle at the target vehicle speed, the vehicle transmission resistance, and the internal resistance of the chassis dynamometer.

[0089] Please refer to Figure 5 , Figure 5 which is the flowchart for determining the wheel end force and frictional resistance on the drum at the target vehicle speed provided by the embodiment of the present application.

[0090] Specifically, the wheel end force and frictional resistance on the drum at the target vehicle speed are calculated in the following manner:

[0091] S301. Determine that the sum of the rolling resistance and the air resistance is equal to the sum of the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor based on the vehicle force balance.

[0092] In this step, an equation is established based on the principle of vehicle force balance. When the vehicle is tested on the drum test bench, the vehicle is affected by multiple forces, including rolling resistance, air resistance, frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor.

[0093] According to Newton's second law (or more specifically, the principle of force balance), these forces must be balanced when the vehicle is traveling (or coasting) steadily.

[0094] Specifically, the sum of the rolling resistance (generated by the contact between the tire and the drum) and the air resistance (generated by the air flow caused by the vehicle's movement) must be equal to the sum of the frictional resistance (i.e., the resistance generated by the relative movement between the tire and the drum), the internal resistance of the drum test bench (i.e., the resistance suffered by the drum itself during rotation), and the force provided by the drum motor (the force applied to simulate the external resistance during actual road driving or to control the drum speed).

[0095] The equation can be expressed as:

[0096] a + bv + cv 2 = F r + F fc + F rc + F dy

[0097] F r + F f + F w = F r + F fc + F rc + F dy

[0098] F f + F w = F fc + F rc + F dy

[0099] where a, b, and c are the coasting resistance coefficients of the vehicle, v is the target speed, F r is the transmission resistance of the vehicle, F f is the rolling resistance, F w is the air resistance, F fc is the frictional resistance between the vehicle and the drum, F rc is the internal resistance of the drum test bench, F dy is the force provided by the drum motor.

[0100] S302. Determine the wheel end force on the drum at the target vehicle speed based on the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor;

[0101] Given the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor, use the equation of vehicle force balance to solve for the wheel end force on the drum. The wheel end force refers to the force acting on the contact surface between the tire and the drum, which is a direct manifestation of the driving or braking force of the vehicle.

[0102] Specifically, rearrange the equation in step S301 to solve for the wheel-end force on the drum (here, consider the wheel-end force on the drum as the resultant force of the rolling resistance and the air resistance, as they are both forces acting on the tire).

[0103] Since we are directly concerned with the situation on the drum and the magnitudes of other forces are known, the wheel-end force on the drum is directly obtained by subtracting the known forces (note that the direction of the forces needs to be considered here to ensure the correctness of the calculation result).

[0104] Therefore, the wheel-end force on the drum is:

[0105] F = F fc + F rc + F dy = F fc + a′ + b′v + c′v 2 + F dy = a + bv + cv 2 - F r

[0106] where a′, b′, and c′ are the coasting resistance coefficients of the drum, v is the target speed, F r is the vehicle transmission resistance, F fc is the friction resistance between the vehicle and the drum, F rc is the internal resistance of the drum test bench, and F dy is the force provided by the drum motor.

[0107] S303. Determine the friction resistance at the target vehicle speed based on the coasting resistance coefficient of the drum, the force provided by the drum motor, the coasting resistance coefficient of the vehicle, and the vehicle transmission resistance.

[0108] In this step, use the known parameters to solve for the friction resistance at the target vehicle speed. The friction resistance is the resistance generated between the tire and the drum due to relative motion, and it is one of the important factors affecting the vehicle's energy flow and dynamic performance.

[0109] According to the last equation on both sides of the formula for calculating the wheel-end force on the drum, knowing the vehicle transmission resistance allows us to derive the friction resistance between the drum and the wheel.

[0110] S104. Determine the vehicle energy flow at the target vehicle speed based on the test data at the target vehicle speed, the wheel-end force on the drum, and the friction resistance. The vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle's power system energy.

[0111] Among them, please refer to Figure 6 , Figure 6 which is the flowchart for determining the vehicle energy flow at the target vehicle speed provided by the embodiments of the present application.

[0112] Among them, the test data includes the current at the output terminal of the vehicle battery, the voltage at the output terminal of the battery, the current at the input terminal of the motor controller, the current voltage at the input terminal of the motor controller, the current at the output terminal of the motor controller, the voltage at the output terminal of the motor controller, the motor speed, and the torque; the vehicle energy flow includes the energy consumption at the battery end, the energy consumption at the input of the motor controller, the energy consumption at the output of the motor controller, the mechanical energy consumption of the motor, the energy consumption of accessories, the loss of vehicle transmission resistance, the energy consumption at the wheel end, and the friction loss.

[0113] Specifically, the vehicle energy flow at the target vehicle speed is determined by the following method:

[0114] S401. Calculate the energy consumption at the battery end according to the current at the output terminal of the battery at the target vehicle speed and the voltage at the output terminal of the battery at the target vehicle speed;

[0115] Here, the energy consumption at the battery end refers to the total amount of electrical energy provided by the battery during discharge. To calculate the energy consumption at the battery end at this target vehicle speed, it is necessary to measure the current and voltage at the output terminal of the battery simultaneously.

[0116] Use a high-precision current sensor or measuring device to monitor and record the current value at the output terminal of the battery in real time. At the target vehicle speed, this current value reflects the magnitude of the current provided by the battery to the motor controller or other loads; similarly, use a high-precision voltage sensor or measuring device to monitor and record the voltage value at the output terminal of the battery in real time, and this voltage value represents the potential difference of the battery during discharge.

[0117] According to the calculation formula of electric power P = VI, multiply the current and voltage at the output terminal of the battery at the target vehicle speed to obtain the instantaneous electric power of the battery at this vehicle speed. Then, perform time integration on the instantaneous electric power (i.e., E = ∫Pdt) to obtain the energy consumption at the battery end at the target vehicle speed.

[0118] Here, in the calculation formula of electric power P = VI and the energy consumption calculation formula E = ∫Pdt, the Chinese meanings of each letter are as follows:

[0119] P: Electric power, with the unit of watt (W). It represents the electrical energy consumed per unit time, that is, the rate of conversion of electrical energy; V: Voltage, with the unit of volt (V). It represents the work done by the electric field force to move a unit charge from one point to another; I: Current, with the unit of ampere (A). It represents the amount of charge passing through the cross-section of a conductor per unit time; E: Energy consumption, with the unit of joule (J) or kilowatt-hour (kWh). It represents the total electrical energy consumed over a period of time; t: Time, with the unit of second (s). It is the integration variable, representing the process of the cumulative electric power over time.

[0120] Explanation of the energy consumption calculation formula:

[0121] E = ∫Pdt means that the energy consumption E is equal to the integral of the electric power P with respect to time t. The physical meaning of this formula is that the energy consumption is the result of the accumulation of electric power over time. By calculating the integral of the electric power over time, the total electric energy consumed at the battery terminal under the target vehicle speed can be obtained.

[0122] S402. Calculate the energy consumption at the input end of the motor controller according to the current at the input end of the motor controller under the target vehicle speed and the voltage at the input end of the motor controller under the target vehicle speed;

[0123] The energy consumption at the input end of the motor controller refers to the total electric energy obtained by the motor controller from the battery or other power sources. To calculate the energy consumption at the input end of the motor controller at this target vehicle speed, it is necessary to measure the current and voltage at the input end of the motor controller.

[0124] Use a current sensor to measure the current value at the input end of the motor controller. This current value reflects the magnitude of the current obtained by the motor controller from the power source; use a voltage sensor to measure the voltage value at the input end of the motor controller. This voltage value represents the potential difference at the input end of the motor controller.

[0125] Similar to the calculation of the energy consumption at the battery terminal, multiply the current and voltage at the input end of the motor controller under the target vehicle speed to obtain the instantaneous electric power of the motor controller at this vehicle speed. Then, perform a time integral on the instantaneous electric power to obtain the energy consumption at the input end of the motor controller under the target vehicle speed.

[0126] S403. Calculate the energy consumption at the output end of the motor controller according to the current at the output end of the motor controller under the target vehicle speed and the voltage at the output end of the motor controller under the target vehicle speed;

[0127] The energy consumption at the output end of the motor controller refers to the total electric energy provided by the motor controller to the motor. To calculate the energy consumption at the output end of the motor controller at this target vehicle speed, it is necessary to measure the current and voltage at the output end of the motor controller.

[0128] Use a current sensor to measure the current value at the output end of the motor controller. This current value reflects the magnitude of the current provided by the motor controller to the motor; use a voltage sensor to measure the voltage value at the output end of the motor controller, and this voltage value represents the potential difference at the output end of the motor controller.

[0129] Multiply the current and voltage at the output end of the motor controller under the target vehicle speed to obtain the instantaneous electric power (output end) of the motor controller at this vehicle speed. Then, perform a time integral on the instantaneous electric power to obtain the energy consumption at the output end of the motor controller under the target vehicle speed.

[0130] S404. Calculate the mechanical energy consumption of the motor according to the motor speed and torque under the target vehicle speed;

[0131] The mechanical energy consumption of the motor refers to the electrical energy consumed during the process of the motor converting electrical energy into mechanical energy. To calculate the mechanical energy consumption of the motor at this target vehicle speed, it is necessary to measure the rotational speed and torque of the motor.

[0132] Use a rotational speed sensor or encoder to measure the rotational speed of the motor. This rotational speed value reflects how fast the motor rotates; use a torque sensor or measuring device to measure the output torque of the motor. This torque value represents the magnitude of the torque generated by the motor during rotation.

[0133] According to the calculation formula of the mechanical power of the motor P = ω×T, where ω is the angular velocity of the motor (proportional to the rotational speed), and T is the torque of the motor, multiply the rotational speed and torque of the motor at the target vehicle speed to obtain the instantaneous mechanical power of the motor at this vehicle speed. Then, perform a time integral on the instantaneous mechanical power to obtain the mechanical energy consumption of the motor at the target vehicle speed.

[0134] S405. Calculate the accessory energy consumption based on the battery terminal energy consumption at the target vehicle speed and the energy consumption at the input end of the motor controller at the target vehicle speed;

[0135] The accessory energy consumption refers to the electrical energy consumed by other electronic devices (such as air conditioners, stereos, etc.) in the vehicle except for the motor controller and the motor. Since these accessories are usually directly connected to the battery, the accessory energy consumption can be obtained by calculating the difference between the battery terminal energy consumption and the energy consumption at the input end of the motor controller; subtract the energy consumption at the input end of the motor controller from the battery terminal energy consumption at the target vehicle speed to obtain the accessory energy consumption at the target vehicle speed.

[0136] S406. Perform a time integral on the vehicle transmission resistance at different vehicle speeds, the wheel end force on the drum at different vehicle speeds, and the frictional resistance at different vehicle speeds to obtain the transmission loss, wheel end energy consumption, and frictional loss at each vehicle speed respectively.

[0137] Here, in the previous steps, the vehicle transmission resistance at different vehicle speeds has been obtained through measurement and calculation. To obtain the transmission loss at the target vehicle speed, it is necessary to perform a time integral on these transmission resistance values. Since the transmission resistance changes with time (especially during the coasting process), it is necessary to integrate the transmission resistance value at each time point to obtain the transmission loss during the entire coasting process.

[0138] The wheel end energy consumption refers to the mechanical energy consumed on the contact surface between the tire and the ground (or drum). To calculate the wheel end energy consumption at this target vehicle speed, it is necessary to measure or calculate the wheel end force on the drum (i.e., the contact force between the tire and the drum), and multiply it by the rotational speed of the tire (proportional to the vehicle speed) to obtain the instantaneous wheel end power. Then, perform a time integral on the instantaneous wheel end power to obtain the wheel end energy consumption at the target vehicle speed.

[0139] Frictional loss refers to the energy loss generated due to relative motion between the tire and the ground (or drum). To calculate the frictional loss at this target vehicle speed, it is necessary to measure or calculate the frictional resistance (such as the calculation process in step S303), and multiply it by the rotational speed of the tire to obtain the instantaneous frictional power. Then, perform a time integration on the instantaneous frictional power to obtain the frictional loss at the target vehicle speed.

[0140] Through the above steps, the vehicle energy flow at each vehicle speed can be comprehensively determined, including various parts such as battery-end energy consumption, motor controller input / output energy consumption, motor mechanical energy consumption, accessory energy consumption, transmission loss, wheel-end energy consumption, and frictional loss.

[0141] Please refer to Figure 7 , Figure 7 which is a schematic diagram of the vehicle energy flow transmission path, as Figure 7 shown. The vehicle energy flow transmission path includes: battery 71, motor controller 72, motor 73, transmission mechanism 74, wheel end 75, and accessory 76.

[0142] Bidirectional energy transmission is achieved between battery 71 and motor controller 72. Battery 71 provides electrical energy to motor controller 72 to enable it to operate normally; in some cases, such as during vehicle braking energy recovery, motor controller 72 will also feedback the recovered energy back to battery 71.

[0143] Bidirectional energy transmission also occurs between motor controller 72 and motor 73. Motor controller 72 converts the electrical energy provided by battery 71 into a form suitable for the operation of motor 73 to drive the motor 73 to rotate; conversely, when motor 73 is in the power generation state, the generated electrical energy will also be transmitted back to motor controller 72.

[0144] Mainly bidirectional energy transmission occurs between motor 73 and transmission mechanism 74. The mechanical energy output by motor 73 is transmitted to wheel end 75 through transmission mechanism 74 to drive the vehicle to travel; in some special working conditions, such as when the vehicle is going downhill, transmission mechanism 74 may transmit the mechanical energy feedback from wheel end 75 to motor 73, making it in the power generation state.

[0145] Bidirectional energy transmission is achieved between transmission mechanism 74 and wheel end 75. Transmission mechanism 74 transmits the mechanical energy output by motor 73 to wheel end 75 to provide driving force for the vehicle; at the same time, the feedback energy of wheel end 75 during braking or driving will also be transmitted back through transmission mechanism 74.

[0146] Battery 71 transmits electrical energy to accessory 76 to provide the energy required for the operation of accessory 76. In the example, accessory 76 includes devices such as water pumps and oil pumps, and the normal operation of these devices depends on the electrical energy provided by battery 71.

[0147] The above is the flow direction of the energy flow. In theory, the energy output by the battery is equal to the sum of the efficiency losses of all components and the energy consumption at the wheel end.

[0148] The vehicle energy flow detection method and detection device provided by the embodiments of the present application include: determining the vehicle transmission resistance when the vehicle is at a target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer when the chassis dynamometer is at the target vehicle speed; obtaining the test data when the vehicle is at the target vehicle speed, where the test data is the data detected when the drive axle of the vehicle is placed on the corresponding drum of the chassis dynamometer and the vehicle is at the target vehicle speed; calculating the wheel end force and frictional resistance on the drum at the target vehicle speed according to the test data, vehicle transmission resistance, and internal resistance of the chassis dynamometer when the vehicle is at the target vehicle speed; determining the vehicle energy flow at the target vehicle speed according to the test data, wheel end force, and frictional resistance on the drum at the target vehicle speed, where the vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle power system energy. Through the present application, the accuracy of vehicle energy flow detection is improved.

[0149] In the present application, in the form of the vehicle drive shaft being suspended, the vehicle transmission resistance in different gears is fitted by coasting. Through force analysis, based on the obtained vehicle transmission resistance, the frictional resistance is deduced. Through force analysis, based on the vehicle transmission resistance, frictional resistance, internal resistance of the chassis dynamometer, and power of the chassis dynamometer, the wheel end power is deduced. The vehicle coasting resistance coefficient is input into the chassis dynamometer, and the driver inputs according to the working conditions and operates the vehicle's acceleration and brake pedals to calculate the wheel end power, input / output electric power of the motor controller, mechanical power of the motor, and battery power in real time, and integrates their time to obtain the battery energy consumption, motor input / output energy consumption, wheel end energy consumption, and internal resistance loss and accessory loss of the vehicle, realizing the energy flow splitting of the entire power chain.

[0150] Based on the same inventive concept, the embodiments of the present application also provide a vehicle energy flow detection device corresponding to the vehicle energy flow detection method. Since the principle of solving problems by the device in the embodiments of the present application is similar to that of the above vehicle energy flow detection method in the embodiments of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0151] Please refer to Figure 8 , Figure 8 which is the structural schematic diagram of the vehicle energy flow detection device provided by the embodiments of the present application. As Figure 8 shown in

[0152] a determination module 801, configured to determine the vehicle transmission resistance when the vehicle is at a target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer when the chassis dynamometer is at the target vehicle speed;

[0153] The test data acquisition module 802 is configured to acquire test data of the vehicle at a target vehicle speed, where the test data is the data detected when the drive axle of the vehicle is placed on the drum corresponding to the chassis dynamometer and the vehicle is at the target vehicle speed;

[0154] The calculation module 803 is configured to calculate the wheel end force and frictional resistance on the drum at the target vehicle speed according to the test data of the vehicle at the target vehicle speed, the vehicle transmission resistance, and the internal resistance of the chassis dynamometer;

[0155] The vehicle energy flow determination module 804 is configured to determine the vehicle energy flow at the target vehicle speed according to the test data at the target vehicle speed, the wheel end force on the drum, and the frictional resistance, where the vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle power system energy.

[0156] Please refer to Figure 9 , Figure 9 which is a schematic structural diagram of the electronic device provided in the embodiment of the present application. As Figure 9 shown in

[0157] the electronic device 300 includes a processor 310, a memory 320, and a bus 330. Figure 1 The memory 320 stores machine-readable instructions executable by the processor 310. When the electronic device 300 runs, the processor 310 communicates with the memory 320 through the bus 330. When the machine-readable instructions are executed by the processor 310, the steps of the vehicle energy flow detection method in the method embodiment as shown above

[0158] can be executed. For the specific implementation manner, reference can be made to the method embodiment, which will not be elaborated here. Figure 1 The embodiment of the present application further provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is run by a processor, the steps of the vehicle energy flow detection method in the method embodiment as shown above

[0159] can be executed. For the specific implementation manner, reference can be made to the method embodiment, which will not be elaborated here.

[0160] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection to each other can be through some communication interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical, or other forms.

[0161] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0162] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0163] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or this part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0164] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed in the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A vehicle energy flow detection method, characterized in that, Including: Determine the vehicle transmission resistance at the target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed; Obtain the test data of the vehicle at the target vehicle speed, where the test data is the data detected when the drive axle of the vehicle is placed on the corresponding drum of the chassis dynamometer at the target vehicle speed; Calculate the wheel end force and frictional resistance on the drum at the target vehicle speed according to the test data of the vehicle at the target vehicle speed, the vehicle transmission resistance, and the internal resistance of the chassis dynamometer; Determine the vehicle energy flow at the target vehicle speed according to the test data, the wheel end force on the drum, and the frictional resistance at the target vehicle speed, where the vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle power system energy.

2. The method according to claim 1, wherein Determine the vehicle transmission resistance at the target vehicle speed in the following way: When the vehicle is in the first test condition, detect the first acceleration without braking force at the target vehicle speed when the vehicle accelerates to the preset vehicle speed and then shifts into different gears and coasts; When the vehicle is in the second test condition, detect the second acceleration with braking force at the target vehicle speed when the vehicle accelerates to the preset vehicle speed and then shifts into different gears and coasts; Determine the vehicle transmission resistance at the target vehicle speed according to the first acceleration and the second acceleration.

3. The method according to claim 2, wherein The first test condition is the condition where the vehicle drive axle is jacked up to lift the drive wheels off the ground, the vehicle is accelerated to the predetermined speed, then shifted into different gears and starts to coast, and the change of the first acceleration during the coasting process is measured. The second test condition is to repeat the operation of the above first test condition, and apply a braking force to the motor before the vehicle accelerates, and measure the change of the second acceleration after the braking force is applied during the coasting process.

4. The method according to claim 1, wherein Determine the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed in the following way: When the drum test bench is in the third test condition, according to the operation manual of the chassis dynamometer, fit the drum coasting resistance coefficient at the target vehicle speed, where the third test condition is that the drum is accelerated to the preset vehicle speed and then coasts according to the vehicle speeds corresponding to different gears; Determine the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed according to the drum coasting resistance coefficient at the target vehicle speed and the target vehicle speed.

5. The method according to claim 4, characterized in that Calculate the wheel end force and frictional resistance on the drum at the target vehicle speed in the following way: According to the vehicle force balance, determine that the sum of the rolling resistance and the air resistance is equal to the sum of the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor; Determine the wheel end force on the drum at the target vehicle speed according to the frictional resistance, the internal resistance of the drum test bench, and the force provided by the drum motor; Determine the frictional resistance at the target vehicle speed according to the drum coasting resistance coefficient, the force provided by the drum motor, the vehicle coasting resistance coefficient, and the vehicle transmission resistance.

6. The method according to claim 5, wherein The test data includes the current at the output terminal of the vehicle battery, the voltage at the output terminal of the battery, the current at the input terminal of the motor controller, the current voltage at the input terminal of the motor controller, the current at the output terminal of the motor controller, the voltage at the output terminal of the motor controller, the motor speed, and the torque. Among them, the vehicle energy flow includes battery end energy consumption, motor controller input energy consumption, motor controller output energy consumption, motor mechanical energy consumption, accessory energy consumption, vehicle transmission resistance loss, wheel end energy consumption, and frictional loss. Among them, the vehicle energy flow at the target vehicle speed is determined by the following method: Calculate the battery terminal energy consumption according to the battery output terminal current and the battery output terminal voltage at the target vehicle speed; Calculate the motor controller input terminal energy consumption according to the motor controller input terminal current and the motor controller input terminal current voltage at the target vehicle speed; Calculate the motor controller output terminal energy consumption according to the motor controller output terminal current and the motor controller output terminal current voltage at the target vehicle speed; Calculate the motor mechanical energy consumption according to the motor speed and torque at the target vehicle speed; Calculate the accessory energy consumption according to the battery terminal energy consumption and the motor controller input terminal energy consumption at the target vehicle speed; Perform time integration on the vehicle transmission resistance, the wheel end force on the drum, and the friction resistance at different vehicle speeds to obtain the transmission loss, the wheel end energy consumption, and the friction loss at each vehicle speed, respectively.

7. The method according to claim 2, characterized in that, The determining the vehicle transmission resistance according to the first acceleration and the second acceleration includes: Construct a first vehicle internal resistance equation according to the first acceleration, the equivalent moment of inertia, and the vehicle mass; Construct a second vehicle internal resistance equation according to the second acceleration, the transmission ratio of the gearbox, the reduction ratio of the final drive, the motor output force, the vehicle transmission resistance, the equivalent moment of inertia, and the vehicle mass; Solve the first vehicle internal resistance equation and the second vehicle internal resistance equation simultaneously to determine the vehicle transmission internal resistance.

8. A vehicle energy flow detection device, characterized in that, It includes: A determination module for determining the vehicle transmission resistance of the vehicle at the target vehicle speed and the internal resistance of the drum test bench of the chassis dynamometer at the target vehicle speed; A test data acquisition module for acquiring the test data of the vehicle at the target vehicle speed, where the test data is the data detected when the drive axle of the vehicle is placed on the corresponding drum of the chassis dynamometer at the target vehicle speed; A calculation module for calculating the wheel end force and the friction resistance on the drum at the target vehicle speed according to the test data, the vehicle transmission resistance, and the internal resistance of the chassis dynamometer of the vehicle at the target vehicle speed; A vehicle energy flow determination module for determining the vehicle energy flow at the target vehicle speed according to the test data, the wheel end force on the drum, and the friction resistance at the target vehicle speed, where the vehicle energy flow is the efficiency and energy consumption of each component during the transmission of the vehicle power system energy.

9. An electronic device, characterized in that, It includes: A processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus, and the processor executes the machine-readable instructions to perform the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and when the computer program is run by the processor, it executes the steps of the method according to any one of claims 1 to 7.

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