Method and device for measuring comprehensive efficiency of electric vehicle, electronic equipment and medium

Abstract

The embodiment of the invention provides a method and device for measuring the comprehensive efficiency of an electric vehicle, electronic equipment and a medium. The method comprises the following steps: controlling the electric vehicle according to a preset test strategy, and synchronously acquiring a half-shaft torque signal of the electric vehicle and a bus current and a bus voltage of a driving motor according to a preset sampling moment; the current state information of the electric vehicle is obtained, the working state of the electric vehicle is determined according to the current state information, and the current state information comprises the rotating speed of the motor; according to the motor rotating speed and the preset half-axle speed ratio, the half-axle rotating speed of the electric automobile is calculated; and generating the comprehensive efficiency of the electric vehicle according to the half-shaft torque signal, the bus current and the bus voltage of the driving motor, the working state and the half-shaft rotating speed. Therefore, the comprehensive efficiency of the electric vehicle is measured, the test precision is remarkably improved, and reliable data support is provided for energy consumption optimization and performance improvement of the whole vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicle performance testing technology, and in particular to a method, device, electronic device and medium for measuring the overall efficiency of an electric vehicle. Background Technology

[0002] Comprehensive efficiency evaluation provides a high-precision, traceable benchmark for vehicle range optimization, control strategy iteration, and regulatory certification, thereby shortening development cycles, reducing testing costs, and enhancing product competitiveness. Currently, pure electric vehicles generally use the CLTC (China Light-duty Vehicle Test Cycle) to evaluate the efficiency performance of the electric drive system under vehicle conditions. CLTC comprehensive efficiency is also a core indicator for horizontal comparison of electric drive products from various manufacturers. Currently, the CLTC comprehensive efficiency testing method for electric drive systems mainly relies on bench testing.

[0003] However, existing bench tests suffer from significant errors in torque results due to the excessively large range of torque sensors, low signal-to-noise ratio at low loads, and inability to eliminate tire slippage. Furthermore, the indirect simulation of vehicle resistance using slip curves inherently deviates from real road loads, leading to distorted reproduction of operating conditions. In addition, the mechanical losses generated by brake caliper intervention during power generation are included in the electric drive system, while caliper power is difficult to measure directly, further amplifying the measurement error of power generation efficiency. Ultimately, the overall efficiency evaluation deviates from the actual performance of the vehicle. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the first objective of this application is to propose a method for measuring the overall efficiency of electric vehicles, which realizes the measurement of the overall efficiency of electric vehicles, significantly improves the test accuracy, and provides reliable data support for the optimization of vehicle energy consumption and performance improvement.

[0006] The second objective of this application is to provide a measuring device for the overall efficiency of an electric vehicle.

[0007] The third objective of this application is to propose an electronic device.

[0008] The fourth objective of this application is to provide a computer-readable storage medium.

[0009] To achieve the above objectives, the first aspect of this application proposes a method for measuring the overall efficiency of an electric vehicle, comprising: controlling the electric vehicle according to a preset test strategy, and synchronously acquiring the half-shaft torque signal, the bus current and bus voltage of the drive motor of the electric vehicle at a preset sampling time; acquiring the current state information of the electric vehicle, and determining the working state of the electric vehicle based on the current state information, wherein the current state information includes the motor speed; calculating the half-shaft speed of the electric vehicle based on the motor speed and a preset half-shaft speed ratio; and generating the overall efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the working state and the half-shaft speed.

[0010] In addition, the method for measuring the overall efficiency of electric vehicles according to the above embodiments of this application may also have the following additional technical features: According to one embodiment of this application, a torque strain gauge is provided on the half-shaft of the electric vehicle, and a current sensor and a voltage sensor are provided at the output terminal of the electric vehicle's inverter. The method of synchronously acquiring the half-shaft torque signal, the bus current of the drive motor, and the bus voltage of the electric vehicle according to a preset sampling time includes: acquiring the half-shaft torque signal of the electric vehicle through the torque strain gauge, wherein the half-shaft torque signal includes the left half-shaft torque and the right half-shaft torque; acquiring the bus current of the drive motor through the current sensor; and simultaneously acquiring the bus voltage of the drive motor through the voltage sensor.

[0011] According to one embodiment of this application, a signal transmitter is provided on the circuit module of the half-shaft, and a signal receiver is provided on the subframe of the electric vehicle. The acquisition of the half-shaft torque signal of the electric vehicle by means of a torque strain gauge includes: when the half-shaft transmits torque, the resistance of the torque strain gauge changes, and a half-shaft torque signal proportional to the torque is output; the signal transmitter receives the half-shaft torque signal and sends the half-shaft torque signal to the signal receiver, so as to obtain the half-shaft torque signal of the electric vehicle through the signal receiver.

[0012] According to one embodiment of this application, the preset half-shaft speed ratio includes a preset left half-shaft speed ratio and a preset right half-shaft speed ratio, and the half-shaft speed includes the left half-shaft speed and the right half-shaft speed. The half-shaft speed of the electric vehicle is calculated based on the motor speed and the preset half-shaft speed ratio, which includes: dividing the motor speed by the preset left half-shaft speed ratio to obtain the left half-shaft speed; and dividing the motor speed by the preset right half-shaft speed ratio to obtain the right half-shaft speed.

[0013] According to one embodiment of this application, the comprehensive efficiency of an electric vehicle is generated based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed. This includes: calculating positive mechanical power and negative mechanical power based on the operating state, left half-shaft torque, right half-shaft torque, left half-shaft speed, and right half-shaft speed; calculating positive electrical power and negative electrical power based on the operating state, bus current, and bus voltage; and calculating the comprehensive efficiency of the electric vehicle based on the positive mechanical power, negative mechanical power, positive electrical power, and negative electrical power. The operating state includes driving state and braking state.

[0014] According to one embodiment of this application, the method for measuring the overall efficiency of an electric vehicle further includes: calculating the driving efficiency of the electric vehicle based on positive mechanical power and positive electrical power; and calculating the power generation efficiency of the electric vehicle based on negative mechanical power and negative electrical power.

[0015] According to one embodiment of this application, the method for measuring the overall efficiency of an electric vehicle further includes: displaying the overall efficiency information through a user interface.

[0016] To achieve the above objectives, a second aspect of this application provides a device for measuring the overall efficiency of an electric vehicle, comprising: a data acquisition module for controlling the electric vehicle according to a preset test strategy and synchronously acquiring the half-shaft torque signal, the bus current and bus voltage of the drive motor at a preset sampling time; a determination module for acquiring the current state information of the electric vehicle and determining the operating state of the electric vehicle based on the current state information, wherein the current state information includes the motor speed; a calculation module for calculating the half-shaft speed of the electric vehicle based on the motor speed and a preset half-shaft speed ratio; and a generation module for generating the overall efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed.

[0017] The electric vehicle comprehensive efficiency measurement device according to the embodiments of this application realizes the measurement of electric vehicle comprehensive efficiency, significantly improves the test accuracy, and provides reliable data support for vehicle energy consumption optimization and performance improvement.

[0018] To achieve the above objectives, a third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned method for measuring the overall efficiency of an electric vehicle.

[0019] The electronic device according to the embodiments of this application can implement the above-mentioned method for measuring the overall efficiency of electric vehicles when the processor executes a computer program. Based on the above-mentioned method for measuring the overall efficiency of electric vehicles, the measurement of the overall efficiency of electric vehicles is realized, the test accuracy is significantly improved, and reliable data support is provided for the optimization of vehicle energy consumption and performance improvement.

[0020] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the aforementioned method for measuring the overall efficiency of an electric vehicle.

[0021] According to the embodiments of this application, a computer-readable storage medium storing a computer program thereon implements the above-described method for measuring the overall efficiency of an electric vehicle when executed by a processor. Based on the above-described method for measuring the overall efficiency of an electric vehicle, the measurement of the overall efficiency of the electric vehicle is realized, significantly improving the test accuracy and providing reliable data support for the optimization of vehicle energy consumption and performance improvement. Attached Figure Description

[0022] Figure 1 This is a flowchart of a method for measuring the overall efficiency of an electric vehicle according to some embodiments of this application; Figure 2 A flowchart of a method for measuring the overall efficiency of an electric vehicle according to a specific embodiment of this application; Figure 3 This is a block diagram of a measuring device for the overall efficiency of an electric vehicle according to some embodiments of this application; Figure 4 This is a block diagram of an electronic device according to some embodiments of this application. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0024] The following describes in detail, with reference to the accompanying drawings, a method, apparatus, electronic device, and medium for measuring the overall efficiency of electric vehicles according to embodiments of this application.

[0025] Figure 1 This is a flowchart of a method for measuring the overall efficiency of an electric vehicle according to some embodiments of this application. (Refer to...) Figure 1 Methods for measuring the overall efficiency of electric vehicles may include: S1 controls the electric vehicle according to the preset test strategy and synchronously collects the half-shaft torque signal, the bus current and bus voltage of the electric vehicle according to the preset sampling time.

[0026] The preset test strategy refers to a pre-defined vehicle operation plan developed under real-world road or test environments to obtain repeatable evaluation results of the electric drive system efficiency. The preset sampling time refers to a pre-defined synchronous sampling point during the execution of the preset test strategy. Both the preset test strategy and the preset sampling time can be set according to actual conditions.

[0027] The half-shaft torque signal refers to an analog or digital signal that is linearly proportional to the actual mechanical torque applied to the half-shaft, used to directly characterize the wheel-end load torque. The drive motor bus current refers to the instantaneous current value measured at the positive or negative terminal of the DC bus in the electric drive system. The drive motor bus voltage refers to the instantaneous voltage value measured between the positive and negative terminals of the DC bus in the electric drive system.

[0028] Specifically, the electric vehicle is first controlled according to a preset test strategy, and the half-shaft torque signal is synchronously acquired and the bus current and bus voltage of the positive or negative DC bus of the drive motor are obtained based on the preset sampling time point, which is defined in advance during the execution of the preset test strategy.

[0029] S2, obtain the current status information of the electric vehicle, and determine the working status of the electric vehicle based on the current status information, wherein the current status information includes the motor speed.

[0030] The current status information refers to the real-time collected status signals characterizing the current operating conditions of the electric vehicle. This information includes the motor speed, which can be obtained from the motor resolver. The operating status refers to the immediate operating mode of the electric vehicle.

[0031] Specifically, the motor speed can be obtained in real time through a motor resolver and incorporated into the current status information. Furthermore, the current operating state of the electric vehicle, i.e., whether it is in driving or generating mode, can be determined based on the current status information.

[0032] S3 calculates the half-shaft speed of the electric vehicle based on the motor speed and the preset half-shaft speed ratio.

[0033] The preset half-shaft speed ratio refers to the fixed transmission ratio between the main reducer and the half-shaft of the electric vehicle. It is determined by the main reduction ratio and the differential gear ratio, and is used to convert the motor speed into the half-shaft speed. The half-shaft speed refers to the rotational angular velocity of the drive half-shaft at the wheel end, and is used to calculate the mechanical power at the wheel end and the vehicle speed.

[0034] Specifically, the obtained motor speed is divided by the preset half-shaft speed ratio to obtain the half-shaft speed of the electric vehicle, which is then used to calculate the overall efficiency of the electric vehicle.

[0035] In some embodiments, an additional magnetoelectric or photoelectric speed sensor may be installed near the half-shaft to directly measure the half-shaft speed.

[0036] S4 generates the overall efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating status, and the half-shaft speed.

[0037] The overall efficiency of an electric vehicle refers to the percentage of the sum of mechanical energy output in the driving state and electrical energy recovered in the power generation state relative to the sum of electrical energy input in the driving state and mechanical energy input in the power generation state. The overall efficiency of the electric vehicle is calculated and output based on energy integral.

[0038] Specifically, based on the collected half-shaft torque signal, the bus current and bus voltage of the drive motor, combined with the working state of the electric vehicle and the calculated half-shaft speed, the overall efficiency of the electric vehicle is generated.

[0039] The electric vehicle under test operates on a real road or test environment according to a preset test strategy. Based on the preset sampling time, the half-shaft torque signal and the DC bus current and voltage of the drive motor are collected synchronously. Then, the output speed of the motor resolver is used as the current state information to determine whether the vehicle is in the driving or power generation state. The half-shaft speed is obtained by dividing the speed by the preset half-shaft speed ratio. Finally, the comprehensive efficiency of the electric vehicle is calculated and output.

[0040] This application achieves accurate measurement of the overall efficiency of electric vehicles by collecting key parameters such as half-shaft torque signal, drive motor bus voltage and drive motor bus current, and calculating half-shaft speed, combined with dynamic evaluation under operating conditions. This significantly improves test accuracy and provides reliable data support for vehicle energy consumption optimization and performance improvement.

[0041] In some embodiments of this application, a torque strain gauge is provided on the half-shaft of the electric vehicle, and a current sensor and a voltage sensor are provided at the output terminal of the electric vehicle's inverter. The simultaneous acquisition of the half-shaft torque signal, the bus current of the drive motor, and the bus voltage of the electric vehicle according to a preset sampling time includes: acquiring the half-shaft torque signal of the electric vehicle through the torque strain gauge, wherein the half-shaft torque signal includes the left half-shaft torque and the right half-shaft torque; acquiring the bus current of the drive motor through the current sensor; and simultaneously acquiring the bus voltage of the drive motor through the voltage sensor.

[0042] Torque strain gauges are resistance strain elements bonded or welded to the surface of the half-shaft, used to output the half-shaft torque signal. Specifically, when the half-shaft transmits torque, it undergoes slight deformation, causing a change in the resistance of the strain gauge. Further, the half-shaft torque signal includes left and right half-shaft torque. The left half-shaft torque refers to the torque transmitted by the left drive half-shaft, directly measured by the left half-shaft's torque strain gauge, and is used to characterize the load on the left wheel end. The right half-shaft torque refers to the torque transmitted by the right drive half-shaft, directly measured by the right half-shaft's torque strain gauge, and is used to characterize the load on the right wheel end.

[0043] In some embodiments, optical torque measurement or magnetostrictive torque sensors can also be used to measure the half-shaft torque, but their cost and ease of installation are not as good as torque strain gauges.

[0044] Current and voltage sensors are installed at the output of the inverter to accurately measure the bus current and voltage when the drive motor is operating.

[0045] Specifically, torque strain gauges are attached or welded to the surfaces of the left and right half-shafts, respectively. At a preset sampling time, the resistance change is synchronously converted into a differential signal, i.e., the half-shaft torque signal. At the same time, current and voltage sensors synchronously output analog bus current and voltage at the DC terminal of the inverter.

[0046] Therefore, by acquiring torque signals from the left and right half-shafts using torque strain gauges and collecting bus current and voltage using current and voltage sensors, accurate data is provided for calculating the overall efficiency of electric vehicles.

[0047] In some embodiments of this application, a signal transmitter is provided on the circuit module of the half-shaft, and a signal receiver is provided on the subframe of the electric vehicle. The acquisition of the half-shaft torque signal of the electric vehicle by means of a torque strain gauge includes: when the half-shaft transmits torque, the resistance of the torque strain gauge changes, and a half-shaft torque signal proportional to the torque is output; the signal transmitter receives the half-shaft torque signal and sends the half-shaft torque signal to the signal receiver, so as to obtain the half-shaft torque signal of the electric vehicle through the signal receiver.

[0048] The signal transmitter is typically a miniaturized wireless transmitter mounted on the rotating half-shaft circuit module. It is used to stably transmit the weak half-shaft torque signal from the torque strain gauge to the vehicle body via wireless telemetry technology. The signal receiver is a wireless receiver mounted on the subframe. It is used to demodulate and output a usable analog or digital signal proportional to the half-shaft torque for subsequent reading.

[0049] Specifically, when the half-shaft transmits torque, the resistance of the torque strain gauge changes, and it outputs a half-shaft torque signal proportional to the torque. The signal transmitter rotates with the half-shaft, transmitting the half-shaft torque signal output by the torque strain gauge wirelessly. A signal receiver fixed to the subframe receives this half-shaft torque signal for subsequent operational data acquisition.

[0050] By using infinite remote sensing technology to achieve stable extraction of half-shaft torque signals, a lossless and delay-free data foundation is provided for comprehensive efficiency calculation.

[0051] In some embodiments of this application, the preset half-shaft speed ratio includes a preset left half-shaft speed ratio and a preset right half-shaft speed ratio, and the half-shaft rotation speed includes the left half-shaft rotation speed and the right half-shaft rotation speed. The calculation of the half-shaft rotation speed of the electric vehicle based on the motor rotation speed and the preset half-shaft speed ratio includes: dividing the motor rotation speed by the preset left half-shaft speed ratio to obtain the left half-shaft rotation speed; and dividing the motor rotation speed by the preset right half-shaft speed ratio to obtain the right half-shaft rotation speed.

[0052] Specifically, the preset half-shaft speed ratio includes the preset left half-shaft speed ratio and the preset right half-shaft speed ratio. The preset left half-shaft speed ratio refers to the fixed transmission ratio between the motor output shaft and the left half-shaft, which is determined by the gear ratio of the main reducer and the left differential, and is used to convert the motor speed into the left half-shaft speed. The preset right half-shaft speed ratio refers to the fixed transmission ratio between the motor output shaft and the right half-shaft, which is determined by the gear ratio of the main reducer and the right differential, and is used to convert the motor speed into the right half-shaft speed.

[0053] The half-shaft speed includes the left half-shaft speed and the right half-shaft speed. The left half-shaft speed refers to the rotational angular velocity of the left drive half-shaft, which is obtained by dividing the motor speed by the preset left half-shaft speed ratio and is used to calculate the mechanical power of the left wheel end. The right half-shaft speed refers to the rotational angular velocity of the right drive half-shaft, which is obtained by dividing the motor speed by the preset right half-shaft speed ratio and is used to calculate the mechanical power of the right wheel end.

[0054] Furthermore, the collected motor speed is divided by the preset left half-shaft speed ratio and the preset right half-shaft speed ratio to obtain the corresponding left half-shaft speed and right half-shaft speed.

[0055] By decomposing the motor speed into the instantaneous speeds of the left and right half-shafts, the mechanical power on both sides can be calculated independently, improving the accuracy and fault tolerance of the overall efficiency calculation.

[0056] In some embodiments of this application, the comprehensive efficiency of an electric vehicle is generated based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed. This includes: calculating positive mechanical power and negative mechanical power based on the operating state, left half-shaft torque, right half-shaft torque, left half-shaft speed, and right half-shaft speed; calculating positive electrical power and negative electrical power based on the operating state, bus current, and bus voltage; and calculating the comprehensive efficiency of the electric vehicle based on the positive mechanical power, negative mechanical power, positive electrical power, and negative electrical power. The operating state includes driving state and braking state.

[0057] The operating states include driving state and braking state. Driving state refers to the vehicle being in traction mode, where the motor outputs positive torque, converting electrical energy into mechanical energy to propel the vehicle forward or backward. Braking state refers to the vehicle being in energy recovery mode, where the motor outputs negative torque, converting mechanical energy into electrical energy to recharge the battery.

[0058] Positive mechanical power refers to the integral sum of the products of the left and right half-shaft torques and their corresponding speeds under driving conditions, representing the traction energy output by the wheels to the road surface. Negative mechanical power refers to the integral sum of the products of the left and right half-shaft torques and their corresponding speeds under braking conditions, representing the mechanical energy input by the road surface to the wheels.

[0059] Positive power refers to the integral of the product of bus voltage and current under driving conditions, representing the electrical energy supplied by the power battery to the drive motor. Negative power refers to the integral of the product of bus voltage and current under braking conditions, representing the electrical energy returned by the motor to the power battery.

[0060] Specifically, the integration operation is performed using the CAN (Controller Area Network) bus data interval as the basic time unit.

[0061] Based on the working state, left half-shaft torque, right half-shaft torque, left half-shaft speed, and right half-shaft speed, the positive mechanical power and negative mechanical power are calculated.

[0062] The positive mechanical power under driving conditions is denoted as P_fdz, and its calculation method can be expressed as: P_fdz=P_fdz+(T_le*N_le+T_ri*N_ri) / 9550, where T_le represents the torque of the left half shaft; T_ri represents the torque of the right half shaft; N_le represents the speed of the left half shaft; and N_ri represents the speed of the right half shaft.

[0063] The negative mechanical power under braking conditions is denoted as P_fdf, and its calculation method can be expressed as: P_fdf=P_fdf+(T_le*N_le+T_ri*N_ri) / 9550, where T_le represents the torque of the left half shaft; T_ri represents the torque of the right half shaft; N_le represents the speed of the left half shaft; and N_ri represents the speed of the right half shaft.

[0064] Based on the operating conditions, bus current, and bus voltage, the positive and negative electric power are calculated.

[0065] The positive power under driving conditions is denoted as P_qdz, and its calculation method can be expressed as: P_qdz=P_qdz+U*I, where U represents the bus voltage and I represents the bus current.

[0066] The negative electric power under braking condition is denoted as P_qdf, and its calculation method can be expressed as: P_qdf=P_qdf+U*I, where U represents the bus voltage and I represents the bus current.

[0067] Furthermore, the overall efficiency of an electric vehicle, denoted as η, can be calculated as: η = (P_qdz + |P_fdf|) / (P_fdz + |P_qdf|) * 100%.

[0068] Therefore, by integrating the mechanical power and electrical power for both driving and braking conditions and unifying their ratios, the overall efficiency can be obtained in real time using the actual energy flow ratio, thus improving the accuracy of calculating the overall efficiency of electric vehicles.

[0069] In some embodiments, a high-precision power analyzer can be used to calculate the overall efficiency of an electric vehicle. A high-precision power analyzer is a data acquisition device with multiple high-precision acquisition channels. Its analog input channels receive half-shaft torque signals, voltage sensor signals, and current sensor signals from signal receivers. The high-speed processor inside the power analyzer processes the data from the analog input channels and uploads it to a host computer via CAN communication.

[0070] In some embodiments of this application, the method for measuring the overall efficiency of an electric vehicle further includes: calculating the driving efficiency of the electric vehicle based on positive mechanical power and positive electrical power; and calculating the power generation efficiency of the electric vehicle based on negative mechanical power and negative electrical power.

[0071] Among them, drive efficiency represents the ratio of mechanical energy output from the wheel end to electrical energy input from the bus in the driving state, reflecting the energy conversion efficiency of the electric drive system during traction; power generation efficiency represents the ratio of electrical energy recovered from the bus to mechanical energy input from the wheel end in the braking state, measuring the energy recovery efficiency.

[0072] Specifically, the driving efficiency, denoted as η_qd, can be calculated as: η_qd = (positive electrical power / positive mechanical power) * 100%. The power generation efficiency, denoted as η_fd, can be calculated as: η_fd = (negative electrical power / negative mechanical power) * 100%.

[0073] Therefore, driving efficiency and power generation efficiency can quantify the energy consumption levels of traction and recovery processes, providing an immediate and high-resolution evaluation basis for accurately optimizing motor control strategies and improving the overall vehicle energy utilization rate.

[0074] In some embodiments of this application, the method for measuring the overall efficiency of an electric vehicle further includes: displaying the overall efficiency information through a user interface.

[0075] Specifically, the raw data (such as half-shaft torque, motor speed, bus voltage and bus current, etc.), calculation process and final efficiency value can be displayed in real time on the user interface in the form of curves, dashboards, numbers, etc., and can be recorded and stored for subsequent analysis.

[0076] In some embodiments, the host computer accesses the vehicle's CAN network via a CAN card to obtain vehicle status signals (such as vehicle speed, gear position, accelerator pedal opening, brake pedal opening, and operating mode) to determine whether the vehicle is currently in drive or power generation mode. Furthermore, the host computer runs efficiency calculation software, such as TSMaster (Test & Simulation Platform), to perform comprehensive efficiency calculations.

[0077] As a specific embodiment of this application, see Figure 2 Methods for measuring the overall efficiency of electric vehicles may include: S201, Install measuring equipment: Attach the torque strain gauge to the drive half-shaft and calibrate the output signal and torque. Fix the matching wireless signal transmitter to the half-shaft. Fix the signal receiver to the subframe and align it with the transmitter. Arrange current and voltage sensors at the DC end of the electric drive system, and connect the sensor output lines to the power analyzer. Connect the power analyzer to a host computer with TSMaster software installed via a network cable.

[0078] S202, Control the electric vehicle and read operating condition data: Control the vehicle according to the preset test strategy, and collect the half-shaft torque signal, bus current and bus voltage of the drive motor and current status information (such as motor speed) of the electric vehicle, and send them to the host computer by the power analyzer.

[0079] S203, Calculate half-shaft speed: TSMaster calculates the half-shaft speed of the electric vehicle based on the collected motor speed and the preset half-shaft speed ratio. S204, Real-time Measurement of Overall Efficiency: TSMaster generates the overall efficiency of the electric vehicle based on the collected half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating status, and the half-shaft speed.

[0080] S205, the user interface displays the measurement results.

[0081] This application also provides a measuring device for the overall efficiency of an electric vehicle, referring to... Figure 3 The device 300 includes: a data acquisition module 310, a determination module 320, a calculation module 330, and a generation module 340.

[0082] The acquisition module 310 is used to control the electric vehicle according to a preset test strategy and synchronously acquire the half-shaft torque signal, the bus current and bus voltage of the drive motor according to a preset sampling time; the determination module 320 is used to acquire the current status information of the electric vehicle and determine the working status of the electric vehicle based on the current status information, including the motor speed; the calculation module 330 is used to calculate the half-shaft speed of the electric vehicle based on the motor speed and the preset half-shaft speed ratio; and the generation module 340 is used to generate the comprehensive efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the working status and the half-shaft speed.

[0083] In some embodiments of this application, a torque strain gauge is provided on the half-shaft of the electric vehicle, and a current sensor and a voltage sensor are provided at the output terminal of the electric vehicle's inverter. The acquisition module 310 synchronously acquires the half-shaft torque signal, the bus current of the drive motor, and the bus voltage of the electric vehicle according to a preset sampling time. Specifically, it is used to: acquire the half-shaft torque signal of the electric vehicle through the torque strain gauge, wherein the half-shaft torque signal includes the left half-shaft torque and the right half-shaft torque; acquire the bus current of the drive motor through the current sensor, and simultaneously acquire the bus voltage of the drive motor through the voltage sensor.

[0084] In some embodiments of this application, a signal transmitter is provided on the circuit module of the half-shaft, and a signal receiver is provided on the subframe of the electric vehicle. The acquisition module 310 acquires the half-shaft torque signal of the electric vehicle through a torque strain gauge. Specifically, it is used to: cause the resistance of the torque strain gauge to change when the half-shaft transmits torque, and output a half-shaft torque signal that is proportional to the torque; the signal transmitter receives the half-shaft torque signal and sends the half-shaft torque signal to the signal receiver so that the half-shaft torque signal of the electric vehicle can be obtained through the signal receiver.

[0085] In some embodiments of this application, the preset half-shaft speed ratio includes a preset left half-shaft speed ratio and a preset right half-shaft speed ratio, and the half-shaft speed includes the left half-shaft speed and the right half-shaft speed. The calculation module 330 calculates the half-shaft speed of the electric vehicle based on the motor speed and the preset half-shaft speed ratio, specifically by: dividing the motor speed by the preset left half-shaft speed ratio to obtain the left half-shaft speed; and dividing the motor speed by the preset right half-shaft speed ratio to obtain the right half-shaft speed.

[0086] In some embodiments of this application, the generation module 340 generates the comprehensive efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed. Specifically, it is used to: calculate positive mechanical power and negative mechanical power based on the operating state, left half-shaft torque, right half-shaft torque, left half-shaft speed, and right half-shaft speed; calculate positive electric power and negative electric power based on the operating state, bus current, and bus voltage; and calculate the comprehensive efficiency of the electric vehicle based on the positive mechanical power, negative mechanical power, positive electric power, and negative electric power. The operating state includes driving state and braking state.

[0087] In some embodiments of this application, the calculation module 330 is further configured to calculate the driving efficiency of the electric vehicle based on the positive mechanical power and the positive electrical power; and to calculate the power generation efficiency of the electric vehicle based on the negative mechanical power and the negative electrical power.

[0088] In some embodiments of this application, the generation module 340 displays the comprehensive efficiency information through a user interface.

[0089] It should be noted that for details not disclosed in the electric vehicle comprehensive efficiency measurement device of this application embodiment, please refer to the details disclosed in the electric vehicle comprehensive efficiency measurement method of this application embodiment, which will not be repeated here.

[0090] Corresponding to the above embodiments, this application also provides an electronic device, specifically referring to... Figure 4 The electronic device 400 includes: a memory 410, a processor 420, and a computer program stored in the memory 410 and executable on the processor 420. The processor 420 executes the program to implement the aforementioned method for measuring the overall efficiency of an electric vehicle.

[0091] This application also provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the aforementioned method for measuring the overall efficiency of an electric vehicle.

[0092] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0093] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0094] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0095] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0096] Any process or method described in the flowchart or otherwise herein is to be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0097] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0098] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0099] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0100] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0101] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

[0102] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0103] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for measuring the overall efficiency of an electric vehicle, characterized in that, include: The electric vehicle is controlled according to a preset test strategy, and the half-shaft torque signal, drive motor bus current and bus voltage of the electric vehicle are collected synchronously according to a preset sampling time. The current status information of the electric vehicle is obtained, and the working status of the electric vehicle is determined based on the current status information, wherein the current status information includes the motor speed; The half-shaft speed of the electric vehicle is calculated based on the motor speed and the preset half-shaft speed ratio. The overall efficiency of the electric vehicle is generated based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed.

2. The method for measuring the overall efficiency of an electric vehicle according to claim 1, characterized in that, The electric vehicle has a torque strain gauge on its half-shaft, and the inverter of the electric vehicle has a current sensor and a voltage sensor at its output terminal. The step of synchronously acquiring the half-shaft torque signal, the bus current of the drive motor, and the bus voltage of the electric vehicle according to a preset sampling time includes: The torque strain gauge is used to collect the half-shaft torque signal of the electric vehicle, wherein the half-shaft torque signal includes the left half-shaft torque and the right half-shaft torque; The bus current of the drive motor is collected by a current sensor, and the bus voltage of the drive motor is collected by a voltage sensor.

3. The method for measuring the overall efficiency of an electric vehicle according to claim 2, characterized in that, A signal transmitter is provided on the circuit module of the half-shaft, and a signal receiver is provided on the subframe of the electric vehicle. The process of acquiring the half-shaft torque signal of the electric vehicle through the torque strain gauge includes: When the half-shaft transmits torque, it causes a change in the resistance of the torque strain gauge, and outputs a half-shaft torque signal that is proportional to the torque. The signal transmitter receives the half-shaft torque signal and sends the half-shaft torque signal to the signal receiver so that the half-shaft torque signal of the electric vehicle can be obtained through the signal receiver.

4. The method for measuring the overall efficiency of an electric vehicle according to claim 2, characterized in that, The preset half-shaft speed ratio includes a preset left half-shaft speed ratio and a preset right half-shaft speed ratio, and the half-shaft rotation speed includes a left half-shaft rotation speed and a right half-shaft rotation speed. The step of calculating the half-shaft rotation speed of the electric vehicle based on the motor rotation speed and the preset half-shaft speed ratio includes: Divide the motor speed by the preset left half-shaft speed ratio to obtain the left half-shaft speed. Divide the motor speed by the preset right half-shaft speed ratio to obtain the right half-shaft speed.

5. The method for measuring the overall efficiency of an electric vehicle according to claim 4, characterized in that, The step of generating the overall efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed includes: Based on the operating state, the torque of the left half-shaft, the torque of the right half-shaft, the rotational speed of the left half-shaft, and the rotational speed of the right half-shaft, the positive mechanical power and the negative mechanical power are calculated. Based on the operating state, the bus current, and the bus voltage, the positive power and negative power are calculated. The overall efficiency of the electric vehicle is calculated based on the positive mechanical power, the negative mechanical power, the positive electrical power, and the negative electrical power; wherein, The operating states include driving state and braking state.

6. The method for measuring the overall efficiency of an electric vehicle according to claim 5, characterized in that, Also includes: The driving efficiency of the electric vehicle is calculated based on the positive mechanical power and the positive electrical power. The power generation efficiency of the electric vehicle is calculated based on the negative mechanical power and the negative electrical power.

7. The method for measuring the overall efficiency of an electric vehicle according to claim 1, characterized in that, Also includes: The comprehensive efficiency information is displayed through a user interface.

8. A device for measuring the overall efficiency of an electric vehicle, characterized in that, include: The acquisition module is used to control the electric vehicle according to a preset test strategy and to synchronously acquire the half-shaft torque signal, the bus current and the bus voltage of the electric vehicle according to a preset sampling time. The determination module is used to acquire the current status information of the electric vehicle and determine the working status of the electric vehicle based on the current status information, wherein the current status information includes the motor speed; The calculation module is used to calculate the half-shaft speed of the electric vehicle based on the motor speed and the preset half-shaft speed ratio. The generation module is used to generate the overall efficiency of the electric vehicle based on the half-shaft torque signal, the bus current and bus voltage of the drive motor, the operating state, and the half-shaft speed.

9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for measuring the overall efficiency of an electric vehicle as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for measuring the overall efficiency of an electric vehicle as described in any one of claims 1-7.

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