CN119643174A - Test system for NVH testing - Google Patents

Abstract

The embodiment of the application provides a test system applied to NVH test. The upper computer is used for determining the input voltage of the magnetic powder brake, adjusting the input voltage of the magnetic powder brake according to the actual steering information and the target steering information, the tested SWA is used for executing the simulated steering operation, and the magnetic powder brake is used for simulating the resistance received by the tested SWA in the steering process and monitoring the actual steering information in the process of executing the simulated steering operation by the tested SWA according to the input voltage in the process of executing the simulated steering operation by the tested SWA. According to the application, the magnetic powder brake is adopted to simulate steering resistance under different driving behaviors and road conditions, so that the technical problem that no actual load is used as a support of a test working condition to cause the distortion of NVH test results in the related art is solved, and the test results are ensured to reflect the NVH performance of SWA under the actual use condition more truly.

Description

Test system applied to NVH test

Technical Field

The embodiment of the application relates to the field of NVH (noise and harshness) tests, in particular to a test system applied to the NVH test.

Background

In the current stage of integration of electric vehicles and intelligent driving technologies, new forms and new application environments are different day by day, and original vehicle parts have mechanical structures and are gradually converted into electric structures.

Specifically, taking steering-by-wire automobile parts as an example, the steering of the traditional automobile body parts consisting of universal joints, universal rods and worm gears is replaced by the steering of the traditional automobile body parts consisting of the universal joints, the universal rods and the worm gears, and the automobile body parts consist of motors and control units. However, the current SWA (Steer-by-WireActuator, a drive-by-wire steering actuator) is a small transmission shaft which is directly connected with a steering wheel, when a driver intentionally steers the steering wheel, after a steering instruction and an intention of the driver are obtained through a steering angle and torque sensor, the direction, the acceleration and the force of the driver for rotating the steering wheel are analyzed and collected, the steering direction, the acceleration and the force are converted into steering linear speed, angular speed and steering torque, the steering linear speed, the angular speed and the steering torque are calculated and logically processed by an ECU (Electronic Control Unit, an electronic control unit) and then are transmitted to the RWA (RoadWheelActuator, a wheel actuator) through a vehicle-mounted CAN (ControllerAreaNetwork, a controller area network), and the RWA drives a mechanical steering structure of the driver to output steering actions, so as to drive the motor vehicle to steer. Meanwhile, RWA transmits data to SWA, SWA carries out road feel feedback through informatization processing, namely reverse action and steering wheel give reverse steering torque to a certain driver, so that the driver is prompted to perceive the resistance relation between the speed and steering of the steering wheel, or the steering wheel is slightly dithered, the driver is prompted to perceive the bumping relation between the motor vehicle and the roughness of the road surface, or the direction is reversed automatically, the driver is prompted to perceive the return relation after the motor vehicle is turned, and the like.

In the conventional NVH (Noise, vibration, ANDHARSHNESS, noise, vibration and harshness) testing process, the test is directly performed in the anechoic chamber, the steering is performed at a specific position of the anechoic chamber, when the test is performed for the steering wheel, the control of the steering wheel is responsible for executing the steering by a tester or a test driver, the measurement and evaluation of the Noise, vibration and harshness are performed by the NVH testing equipment, and the connection of data signals is performed only by the vehicle-mounted CAN network with the lower steering RWA due to the fact that the upper steering work and execution in the cab are only focused. In addition, in more occasions, RWA and SWA are researched and manufactured by different component factories, technical support of RWA is not available when SWA is tested, SWA cannot obtain RWA data in the testing process, and no actual load is used as support of a testing working condition in the NVH testing process, so that the result of NVH testing is distorted.

Disclosure of Invention

The embodiment of the application provides a test system applied to NVH test, which at least solves the technical problem that no actual load is used as a support of a test working condition in the related art, so that the result of NVH test is distorted.

According to one aspect of the embodiment of the application, a test system applied to NVH test is provided, the system comprises a silencing chamber, an upper computer, a magnetic powder brake and a tested SWA, the magnetic powder brake and the tested SWA are arranged in the silencing chamber, the upper computer is respectively and electrically connected with the magnetic powder brake and the tested SWA, the magnetic powder brake is connected with the tested SWA,

The upper computer is used for acquiring target driving information, target road surface information and target steering information in the NVH test in the process of executing the NVH test once, transmitting the target driving information and the target road surface information to the SWA to be tested, determining the input voltage of the magnetic powder brake according to the target driving information and the target road surface information, and transmitting the determined input voltage to the magnetic powder brake;

The tested SWA is used for receiving the target driving information and the target road surface information and executing simulated steering operation according to the target driving information and the target road surface information;

The magnetic powder brake is used for receiving input voltage sent by the upper computer, providing resistance for the tested SWA according to the input voltage in the process of executing the simulated steering operation by the tested SWA so as to simulate the resistance received by the tested SWA in the steering process, monitoring the actual steering information in the process of executing the simulated steering operation by the tested SWA, and sending the actual steering information to the upper computer.

According to the application, in the process of executing one NVH test, the target driving information, the target road surface information and the target steering information in the NVH test are acquired, the tested SWA is controlled to execute the simulated steering operation according to the target driving information and the target road surface information, and in the process of executing the simulated steering operation by the tested SWA, the resistance provided by the magnetic powder brake is accurately controlled according to the target driving information and the target road surface information, the steering resistance under different driving behaviors and road surface conditions is simulated, and the authenticity and the effectiveness of the NVH test are improved. And comparing the actual steering information fed back by the magnetic powder brake with the target steering information, dynamically adjusting the input voltage of the magnetic powder brake, realizing closed-loop control, and improving the precision and efficiency of NVH test. Meanwhile, the automatic control of the upper computer reduces the dependence on manual setting and adjustment, improves the automation level of the test, and reduces the operation complexity and potential human errors.

Drawings

FIG. 1 is a block diagram of an alternative test system for NVH trials in accordance with an embodiment of the present application;

FIG. 2 is a block diagram of an alternative test system for NVH trials in accordance with an embodiment of the present application;

FIG. 3 is a block diagram of yet another alternative test system for NVH trial in accordance with an embodiment of the present application;

FIG. 4 is a schematic illustration of an alternative SWA under test placed on a rubber sleeper according to an embodiment of the present application;

FIG. 5 is a schematic diagram of an alternative disturbance rotator according to an embodiment of the present application;

FIG. 6 is a schematic diagram of an alternative disturbance rotator according to an embodiment of the present application;

FIG. 7 is a front view of an alternative disturbance rotator according to an embodiment of the present application;

FIG. 8 is a top view of an alternative disturbance rotator according to an embodiment of the present application;

FIG. 9 is a side view of an alternative disturbance rotator according to an embodiment of the present application;

the reference numerals are described as follows:

41, rubber sleepers, 42, support structures, 43, SWA under test;

61, a claw carrying fixed disc, 62, a claw carrying rotary disc, 63, a bearing locking snap ring, 64, a coaxial coupling, 65, a bearing and 66, and stirring claws.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the accompanying drawings in conjunction with the embodiments.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

According to an aspect of the embodiment of the present application, there is provided a test system applied to an NVH test, fig. 1 is a block diagram of an alternative test system applied to an NVH test according to an embodiment of the present application, and as shown in fig. 1, the system includes a silencing chamber 102, an upper computer 104, a tested SWA106 and a magnetic powder brake 108, the tested SWA106 and the magnetic powder brake 108 are disposed in the silencing chamber 102, the upper computer 104 is electrically connected with the tested SWA106 and the magnetic powder brake 108, the tested SWA106 is connected with the magnetic powder brake 108,

The upper computer 104 is configured to obtain target driving information, target road surface information and target steering information in an NVH test during execution of the NVH test, send the target driving information and the target road surface information to the SWA106 to be tested, determine an input voltage of the magnetic powder brake 108 according to the target driving information and the target road surface information, send the determined input voltage to the magnetic powder brake 108, receive actual steering information sent by the magnetic powder brake 108, and adjust the input voltage of the magnetic powder brake 108 according to the actual steering information and the target steering information.

The NVH test is a test method for comprehensively testing noise, vibration and harshness generated by a vehicle under various operating conditions. These tests are critical to assessing vehicle comfort and performance, especially during the development phase, to ensure that the vehicle is designed to meet certain NVH standards, enhancing the driving and riding experience.

The upper computer is a control and data processing center in the test system and is responsible for generating and sending control signals, receiving feedback data and analyzing the data. In the embodiment of the application, the upper computer is not placed in the silencing chamber, but can be placed in the control chamber. In the NVH test, the upper computer acquires target driving information, target road surface information and target steering information given in the NVH test, wherein the target driving information refers to vehicle driving condition parameters preset in the NVH test, and aims to simulate specific driving situations. Such information includes, but is not limited to, driving mode (e.g., economy mode, sport mode), vehicle speed, engine speed, drive mode (e.g., four-drive/two-drive), steering information, throttle position, brake effort, etc. The target driving information is used to guide the tested SWA to simulate specific driving behavior, thereby evaluating the NVH performance of the tested SWA in the vehicle under these conditions. In specific practice, basic information of a steering vehicle chassis control domain where the currently tested SWA is located, such as a driving motion mode, a four-wheel drive/two-wheel drive mode, an engine gear, a vehicle speed value, brake control logic and the like, can be configured and simulated according to target driving information, and is directly related to internal control logic of SWA steering, for example, when the driving mode is stopped or idling, the SWA is in an inactive state, the four-wheel drive/two-wheel drive mode can determine whether the SWA steering has a rear wheel drive steering requirement, the engine gear can determine whether the SWA is in a steering ready state, and if the SWA is in a standby and no-output state in a P gear or N gear state. The vehicle speed value is similar to the gear information and the brake control logic is used to determine if SWA is in a brake-slow state. In the case where the target driving information indicates that the SWA is not in the operating state, the NVH test ends.

The target road surface information is a road surface condition parameter simulated in an NVH test and is used for reflecting driving experiences of the vehicle on different road surfaces. Such information includes road flatness, road roughness, road elevation inclination, etc. The setting of the target road surface information helps the test system simulate the NVH response of the vehicle under complex road surface conditions. The target steering information is a steering operation parameter preset in a test, and comprises a desired steering angle, a steering speed, a steering torque and the like, and is used for guiding the target behavior of the tested SWA in the process of simulating the steering operation. Optionally, the target steering information and the steering information in the target driving information may be a set of corresponding relations determined by a preset test outline, that is, in the NVH test, the steering information in the target driving information corresponds to the corresponding target steering information.

And the upper computer controls the magnetic powder brake to provide resistance for the tested SWA according to the target driving information and the target road surface information. Specifically, the upper computer determines the input voltage of the magnetic powder brake according to the target driving information and the target road surface information, so as to control the magnetic powder brake to provide resistance for the tested SWA by giving one input voltage of the magnetic powder brake, and adjusts the input voltage of the magnetic powder brake according to the actual steering information and the target steering information of the tested SWA.

The anechoic chamber is an enclosed space designed to reduce the effects of sound reflections and external noise for noise collection in NVH testing. The anechoic room provides a low noise environment through sound absorbing materials, sound insulation structures and anechoic technology, and ensures the accuracy and repeatability of NVH test data. In this embodiment, a magnetic powder brake and a tested SWA are placed in the silencing chamber to isolate external interference and focus on the collection and analysis of internal NVH signals.

SWA is a steer-by-wire system that controls the steering of a vehicle through electronic signals rather than conventional mechanical linkages. In the NVH test, the tested SWA receives target driving information and target road surface information sent by the upper computer, autonomously calculates steering requirements, and executes simulated steering operation.

The actual steering information refers to data such as steering angle, steering speed, steering torque, etc. that are actually generated by the measured SWA when performing the simulated steering operation. The information is collected through a sensor of the magnetic powder brake and fed back to the upper computer for comparison and adjustment so as to ensure that the steering operation is consistent with preset target steering information.

Illustratively, the upper computer calculates the deviation between the actual steering information and the target steering information by comparing the two, and adjusts the input voltage of the magnetic powder brake based on the deviation between the two to optimize the steering behavior of the tested SWA. Alternatively, a plurality of deviations between the actual steering behavior and the target steering behavior, such as an angle deviation, a speed deviation, a torque deviation, and the like, are calculated from the actual steering information and the target steering information. A closed-loop control algorithm, such as Proportional-integral-derivative control (Proportional INTEGRAL DERIVATIVE, PID control), is typically used. The PID control algorithm dynamically adjusts the input voltage of the magnetic powder brake through three control parameters of proportion (pro), integral (Integral) and Derivative (Derivative) so as to reduce the deviation between the actual steering information and the target steering information.

The tested SWA106 is configured to receive the target driving information and the target road surface information, and perform a simulated steering operation according to the target driving information and the target road surface information.

Optionally, the detected SWA analyzes the received target driving information and the target road surface information to obtain an analysis result, and executes a simulated steering operation according to the analysis result, namely, simulates response and action of the steering system in the actual driving process. This simulated operation is intended to reproduce the steering behavior of the vehicle under specific driving conditions and road conditions to evaluate and optimize vehicle NVH performance.

Alternatively, a simulated steering operation is designed for NVH testing, intended to evaluate vehicle NVH performance, such as steering noise, vibration and harshness, by simulating steering actions in the actual driving experience, including road resistance encountered while steering, vehicle dynamic response, etc. Through the simulation, the NVH characteristics of the tested SWA of the vehicle under different driving and road surface conditions can be obtained, and a basis is provided for subsequent design optimization and verification.

The magnetic powder brake 108 is configured to receive an input voltage sent by the host computer 104, provide a resistance for the tested SWA106 according to the input voltage during the process of performing the simulated steering operation on the tested SWA106, simulate the resistance received by the tested SWA106 during the steering process, monitor actual steering information during the process of performing the simulated steering operation on the tested SWA106, and send the actual steering information to the host computer 104.

The magnetic powder brake can be a controllable magnetic powder brake, and the controllable magnetic powder brake is equipment for controlling braking torque by utilizing a magnetic field and can accurately simulate the resistance encountered by a vehicle during steering. In this embodiment, the magnetic powder brake adjusts the resistance generated by the magnetic powder brake according to the input voltage sent by the upper computer, so as to influence the steering behavior of the tested SWA.

Specifically, the simulated resistance of the magnetic particle brake may include an internal resistance of the steering system when steering based on the target driving information, and a simulated road surface resistance. The internal resistance of the steering system when steering based on the target driving information is mainly derived from friction and damping effects of the steering system itself when steering, including but not limited to friction between components such as motors, gears, couplings, etc. In the process of simulating steering operation, after the tested SWA receives target driving information, the magnetic powder brake can simulate the resistance encountered by the steering system under different driving modes, vehicle speeds and other conditions by adjusting the input voltage. The road resistance is the friction force generated by the contact of the tires with the road under different road conditions during the running of the vehicle. In the NVH test, the magnetic powder brake can also adjust the resistance provided by the magnetic powder brake according to the target road surface information so as to simulate the external resistance encountered by the vehicle when steering under various road surface conditions (such as wet skid, pothole, roughness, inclination and the like). Such simulation helps to evaluate the NVH performance of the vehicle in steering operations under complex road conditions, including noise, vibration, ride comfort, and the like.

Optionally, the magnetic powder hysteresis device is further built in the magnetic powder brake, and is characterized in that after the magnetic powder brake is electrified, magnetic powder has certain resistance, the resistance is in direct proportion to passing voltage, the magnetic powder is linear and the damping is uniform, so that internal resistance and road resistance of a steering system can be simulated by dynamically adjusting the distribution and friction state of the magnetic powder in the magnetic powder brake, a near-real resistance environment is provided for the tested SWA when the simulated steering operation is executed, and the NVH test system can evaluate the NVH performance of the vehicle under different driving and road conditions more comprehensively and finely.

Illustratively, a mechanical connection may be provided between the magnetic particle brake and the SWA under test to provide resistance to the SWA under test 106 to simulate the resistance received by the SWA under test 106 during steering. Alternatively, the magnetic particle brake may be mechanically coupled to the SWA via a coaxial coupling. The coupling allows torque transfer between the two shafts while being able to accommodate small axial and radial excursions, ensuring the stability and reliability of the connection. In the test, the magnetic powder brake simulates different road resistances by changing the intensity of the internal magnetic field, which can be directly transmitted to the drive shaft of the SWA through the coupling, affecting the steering process.

According to the embodiment of the application, in the process of executing one NVH test, the target driving information, the target road surface information and the target steering information in the NVH test are acquired, the tested SWA is controlled to execute the simulated steering operation according to the target driving information and the target road surface information, and in the process of executing the simulated steering operation by the tested SWA, the resistance provided by the magnetic powder brake is accurately controlled according to the target driving information and the target road surface information, the steering resistance under different driving behaviors and road surface conditions is simulated, and the authenticity and the effectiveness of the NVH test are improved. And comparing the actual steering information fed back by the magnetic powder brake with the target steering information, dynamically adjusting the input voltage of the magnetic powder brake, realizing closed-loop control, and improving the precision and efficiency of NVH test. Meanwhile, the automatic control of the upper computer reduces the dependence on manual setting and adjustment, improves the automation level of the test, and reduces the operation complexity and potential human errors.

In an exemplary embodiment, the upper computer 104 is further configured to input the target driving information to a preset driving resistance model to obtain a first resistance output by the preset driving resistance model, where the preset driving resistance model is configured to predict a theoretical steering resistance provided by a driver responding to different driving information, input the target road surface information to the preset road surface resistance model to obtain a second resistance output by the preset road surface resistance model, where the preset road surface resistance model is configured to predict a theoretical resistance of a road surface to wheels under different road surface information, and determine an input voltage of the magnetic powder brake 108 according to the first resistance, the second resistance and a first preset table, where the first preset table is configured to record resistances that can be generated by the magnetic powder brake 108 under different input voltages.

It should be noted that, the preset driving resistance model is used for predicting the theoretical steering resistance provided by the driver responding to different target driving information, and the driving information may include a driving mode, a vehicle speed, a four-wheel drive/two-wheel drive mode, an engine gear, and the like. The preset driving resistance model can be based on dynamic responses of the vehicle under different driving conditions, such as rigidity and damping of a steering system, reaction time of a driver and the like, so that theoretical resistance required by the steering system under different driving modes can be accurately predicted.

The preset road resistance model is used for predicting the theoretical resistance of the road surface to the wheels under different road surface information (such as road surface type, road surface flatness, road surface elevation angle and the like). The preset road resistance model takes into account physical characteristics of the tire in contact with the ground, such as coefficient of friction, compression and recovery processes of the tire, etc., and dynamic response of the vehicle under specific road conditions. By means of the model, theoretical resistance of the wheel under different road conditions such as wet skid, pothole, rough or inclined can be predicted.

The first preset table includes records specific resistance values that the magnetic powder brake can produce at different input voltages. The first preset table is a key for controlling the magnetic powder brake, so that the upper computer can accurately adjust the input voltage of the magnetic powder brake according to preset resistance requirements, and the magnetic powder brake is controlled to provide an accurate resistance value.

Optionally, the first preset table is generated by performing a series of input voltage experiments on the magnetic powder brake under laboratory conditions, simultaneously measuring and recording the resistance or torque generated by the brake under each voltage, performing data analysis, determining the functional relationship between the voltage and the resistance, and establishing a preset table corresponding to the voltage and the resistance, namely the first preset table, based on the functional relationship between the voltage and the resistance. The table may include a plurality of voltage-resistance pairs covering the operating range of the magnetic particle brake.

The upper computer obtains a first resistance output by the preset driving resistance model according to the target driving information input to the preset driving resistance model, inputs the target road surface information to the preset road surface resistance model, obtains a second resistance output by the preset road surface resistance model, and determines the input voltage of the magnetic powder brake according to the first resistance, the second resistance and the first preset table. Alternatively, the first resistance and the second resistance are added (or combined by other mathematical operations, as the case may be) to yield the total target resistance of the steering system under the current test conditions. The total target resistance is the resistance value that the magnetic particle brake needs to provide to simulate the actual steering feel and road resistance. According to the total target resistance, a first preset table is searched, no voltage value which is directly matched in the first preset table is found, and the upper computer may need to use a linear interpolation method to estimate the voltage value which is closest to the total target resistance.

After the upper computer determines the input voltage required by the magnetic powder brake, a control signal for the input voltage is sent to the magnetic powder brake, and after the magnetic powder brake receives the control signal for the input voltage, the distribution state of magnetic powder in the magnetic powder brake is adjusted according to the input voltage so as to change the provided resistance or torque. It should be noted that, the hall sensor or other sensor in the magnetic powder brake continuously monitors the actual output resistance to ensure that the actual output resistance matches the resistance in the first preset table corresponding to the voltage value instructed by the upper computer.

Through the embodiment, the preset driving resistance model and the preset road resistance model can predict the theoretical steering resistance generated by the response of a driver to different driving information and the theoretical resistance of the road surface to wheels under different road surface conditions based on a large amount of actual measurement data and theoretical analysis. The theoretical resistances are converted into the input voltage of the magnetic powder brake through the first preset table, so that accurate resistance control of SWA under simulated driving and road conditions is realized, and the simulation degree of NVH test is enhanced.

In one exemplary embodiment, the tested SWA106 includes an ECU, a motor, and a drive shaft, wherein a preset driving scenario model is provided in the ECU, the preset driving scenario model being used to predict the steering demand of the tested SWA106 under different road surface information and driving information, wherein,

And the ECU is used for inputting the target road surface information and the target driving information into a preset driving scene model to obtain a target steering demand, and controlling the motor and the driving shaft to execute simulated steering operation according to the target steering demand.

The SWA to be tested comprises an ECU, a motor and a driving shaft. The magnetic particle brake may be mechanically coupled to the drive shaft (output shaft) of the SWA via a coaxial coupling. The ECU is provided with a preset driving scenario model. Under the condition that target driving information (such as driving mode, vehicle speed, engine gear, steering information and the like) and target road surface information (such as road surface type, road condition, gradient and the like) are received by the tested SWA, the ECU in the tested SWA analyzes the target driving information and the target road surface information, inputs the target driving information and the target road surface information into a preset driving scene model to predict and obtain corresponding target steering requirements, and accordingly generates corresponding motor control signals according to the target steering requirements to control the motor and the driving shaft to execute simulated steering operation. After receiving the instruction of the ECU, the motor outputs torque to drive the steering shaft to realize preset steering angles and speeds so as to adapt to different driving and road surface conditions and ensure the accuracy and stability of steering operation. The preset driving scene model is used for predicting the steering requirement of the tested SWA under different road surface information and driving information. The steering demand may include steering angle, steering speed, steering torque, and the like.

It should be noted that the preset driving scenario model may be generated based on a large amount of actual driving data. Specifically, performance data of the SWA is collected from a variety of driving scenarios, including, but not limited to, steering angle, steering torque, vehicle speed, engine state, drive mode, braking state, road type, road roughness, road wet degree, and the like. And preprocessing the collected data, including data cleaning, missing value processing, abnormal value detection and the like, so as to ensure the quality of the data. Key features related to steering demand prediction, such as vehicle speed, engine speed, road surface type, etc., are extracted as input parameters of the model. A suitable machine learning algorithm or a physics-based model is selected to construct a preset driving scenario model. Common algorithms include, but are not limited to, support Vector Machines (SVMs), decision trees, random forests, neural networks, or physical-based dynamic models. And using the data processed by the feature engineering, taking the steering requirement (steering angle and steering torque) as a target output of a model, and performing model training. The segmentation data set is a training set and a testing set, the training set data is used for training a model, and the testing set data is used for verifying the generalization capability of the model. And parameters of the model are optimized through methods such as cross verification and grid search, and prediction accuracy is improved. Feature selection, learning rate, regularization term and the like are adjusted, and stability of the model in predicting steering requirements is ensured.

Through the embodiment, through the comprehensive use of the driving situation model, the ECU can generate steering requirements which are very close to actual driving conditions, so that highly simulated steering operation is provided in NVH test.

In an exemplary embodiment, another test system applied to the NVH test is provided, and fig. 2 is a block diagram of another alternative test system applied to the NVH test according to an embodiment of the present application, and as shown in fig. 2, the system further includes:

The TAS signal converter 202, wherein the TAS signal converter 202 is disposed in the silencing chamber 102, one end of the TAS signal converter is electrically connected to the upper computer 104, the other end of the TAS signal converter is electrically connected to the magnetic powder brake 108, and the TAS signal converter is configured to convert an electrical signal sent by the magnetic powder brake 108 into a digital signal and transmit the digital signal to the upper computer 104;

the first CAN signal transceiver 204, wherein one end of the first CAN signal transceiver is electrically connected with the upper computer 104, and the other end is electrically connected with the TAS signal converter;

And a second CAN signal transceiver 206, wherein one end of the second CAN signal transceiver is electrically connected with the upper computer 104, and the other end is electrically connected with the SWA106 to be tested.

The TAS signal converter is responsible for receiving the analog electric signals sent by the magnetic powder brake, converting the analog signals into digital signals, converting continuous analog signals into discrete digital signals by using an analog-to-digital converter (ADC), facilitating the processing and analysis of an upper computer, and then sending the processed digital signals to the upper computer through the electric connection with the first CAN signal transceiver.

The first CAN signal transceiver is used as a bridge between the TAS signal converter and the upper computer and is responsible for transmitting control signals and state feedback between the TAS signal converter and the upper computer. In the embodiment of the application, the first CAN signal transceiver encapsulates the received digital signal into a data frame according to a CAN protocol, and sends the data frame to the upper computer through a CAN bus. Meanwhile, the control command of the upper computer is received, and the control command is unpackaged and then sent to the TAS signal converter, so that the control logic of the magnetic powder brake is affected.

The second CAN signal transceiver is responsible for establishing a communication channel between the upper computer and the SWA to be tested. Specifically, analog steering signals sent by the upper computer, including steering angle, steering torque, etc., are received, and are packaged into data frames according to a CAN protocol, and sent to the ECU of the SWA through the CAN bus, so as to control the motor and the drive shaft in the SWA to perform analog steering operation.

Through the embodiment, the TAS signal converter can convert the analog electric signals sent by the magnetic powder brake into digital signals, so that the accuracy of data is improved, and the follow-up data processing and analysis are facilitated. The first CAN signal transceiver and the second CAN signal transceiver realize real-time communication between the upper computer and the TAS signal converter as well as between the upper computer and the SWA to be tested by using a CAN bus technology, realize that control instructions and state feedback CAN be transmitted in extremely short time, form a high-speed control loop, ensure real-time control and monitoring of the SWA in the test process, and improve the response speed and control precision of the NVH test.

In an exemplary embodiment, the above system further comprises:

And the detection module is used for collecting NVH information in the NVH test.

Wherein, detection module can include a plurality of NVH experimental collectors. Specifically, fig. 3 is a block diagram of another alternative test system applied to NVH test according to an embodiment of the present application, and the detection module may include an NVH collector 302 located in an area where the host computer is located, a first noise collector 304 located in the anechoic chamber, a second noise collector 306 located in the anechoic chamber, and a vibration collector (not shown in the figure) disposed on a driving shaft of the tested SWA 106.

Optionally, the NVH collector 302 located in the area where the upper computer is located is mainly responsible for monitoring and collecting NVH information of the whole test environment, including but not limited to background noise level, environmental vibration condition, and acoustic roughness in the test room.

The first noise collector 304 is used to collect noise signals from within the anechoic chamber, particularly those related to the SWA (steer-by-wire) operation under test. It is able to capture noise generated by SWA motor operation, gear mesh, etc., and thus evaluate SWA noise level and noise characteristics, which are a direct measure of noise aspects in NVH performance.

The second noise collector 306 is similar to the first noise collector, but it may be placed in a different location to capture noise in a different area within the sound deadening chamber or noise of a particular frequency. This allows an overall assessment of the noise contribution of the SWA at different locations and the propagation characteristics of the noise in space.

The vibration collector is directly arranged on the SWA to be tested and is used for collecting vibration data of the SWA when steering operation is carried out. The vibration characteristics of components such as a steering shaft, a motor, a gear box and the like can be captured, and the vibration characteristics comprise vibration frequency, amplitude, vibration mode and the like.

Wherein, in the case of performing a steering operation based on the target driving information and the target road surface information, NVH information of SWA is recorded, including a series of noises, steering shaft vibrations, and overall sound vibration roughness under the performance of the simulated steering operation. The NVH information is used for assessment of SWA NVH performance and optimization of the test system.

In specific practice, the test result is compared with a preset NVH performance standard by utilizing the data processing and analyzing functions of the upper computer. The preset NVH performance standard is based on NVH design targets of the vehicle under different working conditions, and generally comprises indexes such as noise level, vibration frequency and amplitude, irregularity evaluation and the like. The NVH test results at SWA do not meet the expected criteria, which indicates that there is insufficient NVH performance of SWA under the current set conditions, possible reasons include design defects, manufacturing quality problems, improper control strategies, and the like.

According to the embodiment, the NVH performance of the SWA in the simulated driving scene can be accurately evaluated through the NVH information in the NVH test acquired by the detection module.

In one exemplary embodiment, the floor of the anechoic chamber 102 is placed with a rubber sleeper on which both the SWA under test 106 and the magnetic particle brake 108 are placed.

The rubber sleeper is made of a material with high elasticity and good sound absorption and shock absorption performance, and aims to form an isolation layer between the SWA and the magnetic powder brake and the ground and reduce vibration transmission and noise reflection caused by direct contact.

The anechoic chamber is typically designed to acoustically isolate the environment, with the interior walls and floor being specially treated to minimize external noise and vibration interference. The use of rubber sleepers further enhances this isolation effect, providing a more desirable mute and vibration damping environment for NVH testing.

According to the embodiment, the rubber sleeper is arranged on the ground of the anechoic chamber, and the tested SWA and the magnetic powder brake are both arranged on the rubber sleeper, so that a more ideal silencing and vibration damping environment is provided for NVH test, and the accuracy of test results of the NVH test is improved.

In one exemplary embodiment, the tested SWA106 and the magnetic particle brake 108 are each placed on a rubber sleeper through a support structure, and the support structure of the tested SWA106 and the support structure of the magnetic particle brake 108 are connected by an on-frequency resonant rod.

The tested SWA and the magnetic powder brake are placed on the rubber sleeper through the supporting structure, and a plurality of rubber pad feet distributed in a point shape can be arranged at the bottom of the supporting structure and are directly contacted with the rubber sleeper. The design ensures the stable support of the equipment, and simultaneously utilizes the shock absorption and sound insulation properties of the rubber to effectively isolate the vibration and noise when the equipment is operated.

The same-frequency resonance rod is used as a mechanical connecting piece, one end of the same-frequency resonance rod is connected with the output shaft of the SWA, and the other end of the same-frequency resonance rod is connected with the input shaft of the magnetic powder brake. This way of connection enables the magnetic particle brake to provide real-time resistance simulation according to the steering action of the SWA while ensuring that the force and vibration transfer between the two is performed at the same frequency, avoiding unnecessary resonance disturbances. Optionally, the same-frequency resonance rod is made of a rigid material, and carbon steel is generally selected, so that the same-frequency resonance rod has the advantages of high hardness, uniformity and high vibration frequency transmission characteristic.

Specifically, FIG. 4 is a schematic illustration of an alternative SWA under test placed on a rubber sleeper according to an embodiment of the present application. As shown in fig. 4, a rubber sleeper 41, a support structure 42, and a SWA43 to be tested. In the anechoic chamber, the ground is provided with rubber sleepers 41, and the rubber sleepers 41 support the SWA43 to be measured by a plurality of support structures 42. Alternatively, the plurality of support structures may be non-perpendicular to the floor of the sound attenuation chamber, i.e., on the rubber sleeper.

Through the embodiment, based on the connection of the same-frequency resonant rod, the magnetic powder brake can respond to the steering action of the SWA in real time and provide accurate resistance simulation, and the connection mode ensures the synchronization of the resistance and the steering action in the test process, is favorable for simulating the damping and the force feedback under the real driving working condition, and improves the authenticity and the reliability of the NVH test.

In one exemplary embodiment, the support structure of the tested SWA106 is a first number of rigid shock bars and the support structure of the magnetic particle brake 108 is a second number of rigid shock bars, with on-frequency resonant bars connecting at least part of the rigid shock bars of the tested SWA106 and at least part of the rigid shock bars of the magnetic particle brake 108.

The rigid shock absorbing rod for supporting the tested SWA and the magnetic powder brake is made of high-strength steel or aluminum alloy materials, so that the rigidity and stability of the structure are ensured. The shock absorbing rods are generally distributed in a V-shape or an X-shape to uniformly distribute the weight of the equipment and to enhance the stability of the support.

A first number of rigid shock bars is used to support SWA and a second number of rigid shock bars is used to support the magnetic powder brake 108. The first and second numbers are sized according to the weight, size and expected vibration frequency of the device to ensure sufficient support stability and vibration isolation. Typically, the first number may be 4 and the second number may be 2.

The rigid shock absorbing rod can be made of rigid materials, the rigidity is expressed as surface rigidity, the inside is different from the surface amplitude, the surface hardening treatment of aluminum alloy is generally needed to be respectively and rigidly connected with the SWA and the magnetic powder brake, and the actual situation of vehicle installation is simulated, so that the SWA can effectively conduct the vibration during test operation, and the natural vibration frequency and the conduction characteristic of an object are simulated to keep the same as possible with the real vehicle.

Through the combined use of the rigid shock absorbing rod and the rubber sleeper, vibration generated during operation of the SWA and the magnetic powder brake can be effectively isolated, and transmission of the vibration to the test bench is reduced, so that accuracy of NVH test is improved.

In one exemplary embodiment, the magnetic particle brake 108 includes a disturbance rotator including a plurality of stirring jaws with grooves and a rotating structure, wherein,

The stirring claw is in a multi-stage ladder form, at least one groove is formed in each stage, the stirring claws are fixed on the rotating structure, and the stirring claws are used for rotationally stirring magnetic powder in the magnetic powder brake 108 so as to generate torque;

And the rotating structure is used for driving the plurality of stirring claws to rotate based on the input voltage of the magnetic powder brake 108.

Wherein the disturbance rotator may be composed of a plurality of stirring claws with grooves and a rotating structure. The stirring claw adopts a multi-section ladder shape, and each section ladder is provided with at least one groove so as to rotationally stir the magnetic powder in the magnetic powder brake, so that the contact area between the stirring claw and the magnetic powder can be increased, the stirring efficiency is improved, and the torque is generated more effectively during rotation. The stirring claws are uniformly fixed on the rotating structure, so that the balance in the rotating process is ensured, and the extra vibration caused by unbalanced structure is avoided.

The grooves can not only contain magnetic powder, but also enable the edges of the grooves to be in contact with the magnetic powder in the rotating process, so that friction force is generated, and the friction force is converted into torque. When the stirring claw in the multi-stage ladder type rotates, the interaction of grooves with different depths and magnetic powder can generate more complex and accurate torque output, and the resistance change to SWA under different road conditions and working conditions is simulated.

The rotational speed and direction of the rotating structure are controlled by the input voltage of the magnetic powder brake. Optionally, the upper computer can accurately control the rotating speed of the rotating structure by adjusting the input voltage, so as to control the stirring degree of the stirring claw on the magnetic powder, and achieve the purpose of adjusting the torque output. Specifically, FIG. 5 is a schematic diagram of an alternative disturbance rotator according to an embodiment of the present application.

Through the design of the multistage stepped claw and the groove of the disturbance rotator, preset torque can be accurately generated under different input voltages, so that resistance change of SWA in actual driving can be accurately simulated by NVH test, and the authenticity and reliability of the test are improved.

In one exemplary embodiment, the disturbance rotator has a rotational speed sensor mounted thereon, wherein,

The rotation speed sensor is used for detecting actual steering information when the tested SWA106 performs the simulated steering operation.

The magnetic powder brake is provided with a disturbance rotator, a rotating speed sensor can be installed on the disturbance rotator, and the rotating speed sensor can be used for detecting actual steering information of the tested SWA when the magnetic powder brake provides resistance for the tested SWA according to input voltage in the process of executing simulated steering operation by the tested SWA.

Through the embodiment, the rotating speed sensor is used for detecting actual steering information when the tested SWA executes the simulated steering operation, so that the upper computer can timely adjust the input voltage of the magnetic powder brake according to the difference value between the actual steering information and the target steering information, and more accurate resistance control is realized.

In an exemplary embodiment, fig. 6 is a schematic view of another alternative disturbance rotator according to an embodiment of the present application, and as shown in fig. 6, the rotating structure includes a claw carrying fixed disk 61, a claw carrying rotating disk 62, a bearing locking snap ring 63, a coaxial coupling 64, and a bearing 65, a plurality of stirring claws 66 are fixed on the claw carrying fixed disk 61, wherein,

One end of the claw carrying fixed disk 61 is connected with a plurality of stirring claws 66, the other end is connected with a claw carrying rotary disk 62, and the claw carrying fixed disk 61 is used for fixing the plurality of stirring claws 66;

One end of the claw carrying rotary disk 62 is connected with a claw carrying fixed disk 61, and the other end is connected with a bearing locking snap ring 63, wherein the claw carrying rotary disk 62 is used for driving a coaxial coupler 64 to rotate;

One end of the bearing locking snap ring 63 is connected with a claw-carrying rotary disk 62, and the other end is connected with a coaxial coupling 64;

One end of the coaxial coupler 64 is connected with a bearing locking snap ring 63, and the other end is connected with a bearing 65;

One end of a bearing 65 is fixed on the claw-carrying rotary disk 62, and the other end sequentially passes through the bearing locking snap ring 63 and the coaxial coupling 64.

Wherein, the claw carrying fixed disk is a circular disk-shaped structure for fixing and supporting a plurality of stirring claws. The claw carrying fixed disc is connected with a plurality of stirring claws through one end of the claw carrying fixed disc, and the other end of the claw carrying fixed disc is connected with the claw carrying rotary disc, so that the stirring claws can stably keep the positions when rotating and can rotate together with the claw carrying rotary disc. The stirring claw is designed into a multi-stage ladder type, and each stage ladder is provided with at least one groove for stirring magnetic powder in the magnetic powder brake. The other end of the claw carrying fixed disc is connected with the claw carrying rotary disc through a fastener, and the claw carrying rotary disc drives the stirring claw to rotate together through the claw carrying fixed disc when rotating, so that stirring of magnetic powder is realized.

The claw carrying rotary disk is a rotary part of the disturbance rotator, and is connected with the claw carrying fixed disk through one end, and the other end is connected with the bearing locking snap ring. The claw carrying rotary disk drives the claw carrying fixed disk and the stirring claw fixed on the claw carrying rotary disk to rotate together when rotating, so that disturbance is generated when SWA executes steering operation, and the dynamic change in road surface unevenness or running is simulated.

The bearing locking snap ring is an annular component for fixing the bearing and the coaxial coupler and is positioned at one end of the claw-carrying rotary disk. The rotary mechanism is connected with the claw carrying rotary disk, and meanwhile, the bearing is ensured not to displace in the rotation process, so that stability and support are provided for the rotary structure.

The coaxial coupling is a component connecting the jaw-carrying rotary disk and the bearing, and is used for transmitting the rotary motion of the jaw-carrying rotary disk to the bearing, and simultaneously keeping the consistency of the rotary axes of the jaw-carrying rotary disk and the bearing. The use of coaxial couplings ensures smooth and efficient transmission of rotational motion.

Bearings are critical components in rotating structures for reducing friction and wear of the rotating component contact surfaces, as well as for transmitting rotational motion. One end of the bearing is fixed on the claw-carrying rotary disk, and the other end of the bearing passes through the bearing locking snap ring and the coaxial coupling and is connected with an external rotary shaft or other mechanical parts. The presence of the bearings ensures smoothness and reliability of the perturbed rotator in rotation.

For a better understanding of the specific structure of the disturbance rotator, it is shown in fig. 7 to 9, where fig. 7 is a front view of an alternative disturbance rotator according to an embodiment of the application, fig. 8 is a top view of an alternative disturbance rotator according to an embodiment of the application, and fig. 9 is a side view of an alternative disturbance rotator according to an embodiment of the application.

Through the precise design of the rotating structure, particularly the cooperation of the claw carrying rotating disk and the claw carrying fixed disk, the stirring claw can uniformly and efficiently stir magnetic powder during rotation, and further precise control of torque is realized, so that the high precision requirement of simulation resistance in NVH test is met.

It will be appreciated by those skilled in the art that the modules or steps of the application described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may be implemented in program code executable by computing devices, so that they may be stored in a storage device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than that shown or described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps of them may be fabricated into a single integrated circuit module. Thus, the present application is not limited to any specific combination of hardware and software.

The above is only a preferred embodiment of the present application, and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the principle of the present application should be included in the protection scope of the present application.

Claims (11)

1. A test system applied to NVH test is characterized by comprising a silencing chamber, an upper computer, a magnetic powder brake and a tested SWA, wherein the magnetic powder brake and the tested SWA are arranged in the silencing chamber, the upper computer is respectively and electrically connected with the magnetic powder brake and the tested SWA, the magnetic powder brake is connected with the tested SWA,

The upper computer is used for acquiring target driving information, target road surface information and target steering information in the NVH test in the process of executing the NVH test once, transmitting the target driving information and the target road surface information to the SWA to be tested, determining the input voltage of the magnetic powder brake according to the target driving information and the target road surface information, and transmitting the determined input voltage to the magnetic powder brake;

The tested SWA is used for receiving the target driving information and the target road surface information and executing simulated steering operation according to the target driving information and the target road surface information;

The magnetic powder brake is used for receiving input voltage sent by the upper computer, providing resistance for the tested SWA according to the input voltage in the process of executing the simulated steering operation by the tested SWA so as to simulate the resistance received by the tested SWA in the steering process, monitoring the actual steering information in the process of executing the simulated steering operation by the tested SWA, and sending the actual steering information to the upper computer.

2. The system of claim 1, wherein the host computer is further configured to input the target driving information to a preset driving resistance model to obtain a first resistance output by the preset driving resistance model, wherein the preset driving resistance model is configured to predict a theoretical steering resistance provided by a driver in response to different driving information, input the target road surface information to a preset road surface resistance model to obtain a second resistance output by the preset road surface resistance model, wherein the preset road surface resistance model is configured to predict a theoretical resistance of a road surface to wheels under different road surface information, and determine an input voltage of the magnetic powder brake according to the first resistance, the second resistance and a first preset table, wherein the first preset table is configured to record resistances generated by the magnetic powder brake under different input voltages.

3. The system of claim 1, wherein the SWA under test comprises an ECU, a motor, and a drive shaft, wherein a preset driving scenario model is provided in the ECU, the preset driving scenario model being used to predict steering requirements of the SWA under different road surface information and driving information,

And the ECU is used for inputting target pavement information and target driving information into the preset driving scene model to obtain a target steering demand, and controlling the motor and the driving shaft to execute the simulated steering operation according to the target steering demand.

4. The system of claim 1, wherein the system further comprises:

The TAS signal converter is arranged in the silencing chamber, one end of the TAS signal converter is electrically connected with the upper computer, the other end of the TAS signal converter is electrically connected with the magnetic powder brake, and the TAS signal converter is used for converting an electric signal sent by the magnetic powder brake into a digital signal and transmitting the digital signal to the upper computer;

the first CAN signal transceiver, wherein one end of the first CAN signal transceiver is electrically connected with the upper computer, and the other end of the first CAN signal transceiver is electrically connected with the TAS signal converter;

and one end of the second CAN signal transceiver is electrically connected with the upper computer, and the other end of the second CAN signal transceiver is electrically connected with the SWA to be tested.

5. The system of claim 4, wherein the system further comprises:

and the detection module is used for collecting NVH information in the NVH test.

6. The system of claim 4, wherein the floor of the anechoic chamber is provided with a rubber sleeper, and the SWA under test and the magnetic particle brake are both placed on the rubber sleeper.

7. The system of claim 6, wherein the SWA under test and the magnetic particle brake are each placed on the rubber sleeper by a support structure, the support structure of the SWA under test and the support structure of the magnetic particle brake being connected by an on-frequency resonant rod.

8. The system of claim 7, wherein the support structure of the SWA under test is a first number of rigid shock bars and the support structure of the magnetic particle brake is a second number of rigid shock bars, the on-frequency resonant bars connecting at least a portion of the rigid shock bars of the SWA under test and at least a portion of the rigid shock bars of the magnetic particle brake.

9. The system of any one of claims 1 to 8, wherein the magnetic particle brake comprises a disturbance rotator comprising a plurality of stirring jaws with grooves and a rotating structure, wherein,

The stirring claws are in a multi-stage ladder form, each stage ladder is provided with at least one groove, a plurality of stirring claws are fixed on the rotating structure, and the stirring claws are used for rotationally stirring magnetic powder in the magnetic powder brake so as to generate torque;

The rotating structure is used for driving the stirring claws to rotate based on the input voltage of the magnetic powder brake.

10. The system of claim 9, wherein the rotating structure comprises a jaw-carrying stationary plate, a jaw-carrying rotating plate, a bearing-locking snap ring, a coaxial coupling, and a bearing, wherein a plurality of the agitating jaws are secured to the jaw-carrying stationary plate,

One end of the claw carrying fixing disc is connected with a plurality of stirring claws, the other end of the claw carrying fixing disc is connected with the claw carrying rotating disc, and the claw carrying fixing disc is used for fixing the plurality of stirring claws;

one end of the claw carrying rotary disk is connected with the claw carrying fixed disk, and the other end of the claw carrying rotary disk is connected with the bearing locking snap ring, wherein the claw carrying rotary disk is used for driving the coaxial coupling to rotate;

One end of the bearing locking snap ring is connected with the claw carrying rotary disk, and the other end of the bearing locking snap ring is connected with the coaxial coupling;

one end of the coaxial coupler is connected with the bearing locking snap ring, and the other end of the coaxial coupler is connected with the bearing;

one end of the bearing is fixed on the claw carrying rotary disk, and the other end of the bearing sequentially penetrates through the bearing locking snap ring and the coaxial coupling.

11. The system of claim 9, wherein the disturbance rotator has a rotational speed sensor mounted thereon, wherein,

The rotating speed sensor is used for detecting the actual steering information when the tested SWA executes the simulated steering operation.