An electromagnetic compatibility test system and method for intelligent connected vehicle steer-by-wire

Abstract

The present invention provides an electromagnetic compatibility test system and method for wire-controlled steering of intelligent connected vehicles, which can solve the technical conflicts that prevent the implementation of precise black box testing of wire-controlled steering of intelligent connected vehicles, and provide a test system and method with strong adaptability that can be deployed in an electromagnetic compatibility darkroom. By controlling the steering actuator on the steering wheel, the vehicle steering system is manipulated to rotate to a set angle at a set angular velocity, and a camera is used to capture the graphics of the chessboard deployed on the outside of the steering wheel. Based on the processor, the image is analyzed to obtain information such as the actual steering angle, and then the steering function test result is obtained. The test system and method disclosed in the present invention have the advantages of high adaptability, low cost, and convenient deployment. It is suitable for autonomous driving vehicles with various sensor architectures and function / scenario definitions, has extremely high industrial application value, and can meet the current and future needs of wire-controlled steering test evaluation.

Description

Technical Field

[0001] The present invention belongs to the field of automobiles, and in particular relates to an electromagnetic compatibility testing system and method for intelligent networked automobile steering-by-wire. Background Art

[0002] The vehicle steering system is responsible for the lateral control of the vehicle. In the traditional steering system, the driver transmits the operation of the steering wheel to the steering wheel through mechanical devices (such as steering gear and tie rods) to achieve the steering of the vehicle. Early mechanical hydraulic power steering systems, as well as the modern widely used electro-hydraulic power steering and electric power steering systems, are all steering systems based on mechanical rigid connections. These mechanical systems are designed to optimize the transmission of steering force, reduce the driver's control burden through power assistance, and improve the stability and ride quality of the vehicle. However, the limitations of the mechanical structure make it impossible to flexibly adjust the steering angle transmission characteristics, making it difficult to meet the refined control requirements required for autonomous driving.

[0003] Intelligence has become the future development direction of the automobile industry. Autonomous driving is the core technology of automobile intelligence, and the research and application of wire-controlled steering technology is the key link to realize autonomous driving. With the maturity of electronic technology, automatic control technology and the popularization of communication technology, wire-controlled steering systems have emerged and gradually replaced traditional mechanical connections. The wire-controlled steering system eliminates the mechanical rigid connection components between the steering wheel and the steering wheel, and realizes steering through electronic signal control. The wire-controlled steering system not only has the advantages of the traditional mechanical steering system, but also optimizes the angle transfer characteristics and provides control flexibility that traditional mechanical systems cannot achieve. In the wire-controlled system, the driver's operating signal is converted into an electrical signal through a sensor, and after analysis and processing, it is transmitted to the steering actuator through a wire to realize steering control. Therefore, the wire-controlled steering system can theoretically achieve any steering angle, beyond the limitations of the mechanical structure.

[0004] During the application process, the performance of the wire-controlled steer system needs to focus on several characteristics: first, the synchronization of the rotation of the steering wheel and the wheels, that is, the steering delay; second, whether the steering wheel can accurately control the wheels to turn to the specified angle; and finally, whether the automatic adjustment of the steering transmission ratio at different vehicle speeds meets the design requirements. With the increasing complexity of the wire-controlled system, the normal operation of each environment depends on the normal operation of various electronic systems. Especially under external conditions of electromagnetic interference, system failures may cause abnormalities in the autonomous driving function, or even cause the vehicle to lose control, resulting in casualties and serious property losses. Therefore, the testing of the electromagnetic compatibility and fault tolerance of the wire-controlled steer system needs to be accurate enough to ensure its safety and reliability in autonomous driving applications. Summary of the invention

[0005] The invention discloses an electromagnetic compatibility test system and method for intelligent network-connected vehicle steer-by-wire, so as to solve the problem in the prior art that the vehicle steer-by-wire function cannot be accurately tested under electromagnetic interference conditions.

[0006] In order to solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0007] One aspect of the present invention provides an electromagnetic compatibility test system for intelligent connected vehicle steer-by-wire, which is used to test the steer-by-wire function of the vehicle in an electromagnetic environment. The test system includes:

[0008] A steering actuator fixed to the steering wheel is configured to perform a steering operation according to a received steering command;

[0009] A circular chessboard fixed to the outer side of the steering wheel, wherein the midpoint of the chessboard coincides with the midpoint of the steering wheel;

[0010] A camera fixedly connected to the vehicle, configured to capture an image of a complete chessboard along the axle direction of the steering wheel;

[0011] A processor that is communicatively connected to the steering actuator and the camera is configured to send a steering instruction to the steering actuator, capture a checkerboard image captured by the camera, and obtain a steering function test result based on the steering condition of the steering actuator and the change in the outline of the checkerboard in the image.

[0012] Optionally, the radius of the chessboard is smaller than the radius of the steering wheel.

[0013] Optionally, the camera is a high-speed camera, and the center point of the optical axis is located on the extension line of the axle direction.

[0014] Optionally, the processor includes the following units:

[0015] A steering command unit in communication with the steering actuator, configured to generate a steering command based on steering data input by a user and send the steering command to the steering actuator, wherein the steering data includes a steering speed, a steering angle, a step time, and a dwell time;

[0016] The image unit is connected to the camera in communication, and is configured to control the camera to continuously capture images of the chessboard after receiving a capture instruction, and store each image and the capture time;

[0017] The analyzing unit is connected to the image unit in communication and is configured to obtain the steering wheel The starting time of the turn and stop time , and obtain The distance L between the midpoint and the edge of the chessboard in the corresponding image parallel to the driving ground, and The distance M between the midpoint and edge of the chessboard in the corresponding image parallel to the driving ground is calculated according to the following formula: The actual turning angle of the secondary steering :

[0018]

[0019] in, , is the total number of steering wheels turning during the test;

[0020] The test result unit is respectively connected to the analysis unit and the steering actuator in communication, and is configured to collect the steering actuator first The starting time of the turn action and stop time , and the actual steering angle , and according to the steering wheel The starting time of the turn , Stop time and the actual rotation angle , obtaining a steering function test result, wherein the steering function test result at least includes a steering angle error and a steering delay.

[0021] Optionally, the test result unit includes the following subunits:

[0022] The steering angle error unit is configured to The actual rotation angle after the first turn, and the steering actuator The actual steering angle after the first steering action is calculated as Steering angle error relative to the steering actuator after the first turn;

[0023] The steering delay unit is configured to The start and end time of the second turn, as well as the first The start and end time of the steering action are calculated. Steering delay relative to the steering actuator after the first turn;

[0024] The steering delay unit is further configured to obtain a maximum steering delay and an average steering delay according to a steering delay of each steering of the steering wheel.

[0025] Optionally, the test result unit further includes the following subunits:

[0026] The parameter comparison unit, which is in communication connection with the vehicle speed sensor on the vehicle, is configured to obtain the actual turning angle of the steering wheel and the actual steering angle of the steering actuator for each set vehicle speed when the steering actuator receives the same steering instruction at multiple set vehicle speeds, and calculate the actual steering ratio at the set vehicle speed according to the following formula:

[0027]

[0028] The actual steering ratio at each set vehicle speed is compared with the corresponding preset steering ratio parameter, and the difference between the actual steering ratio and the steering ratio parameter is calculated as the steering ratio error in the steering function test result.

[0029] Optionally, the parameter comparison unit is further connected to the steering actuator in communication, and is configured to obtain the current rotation angle of the steering actuator when the steering wheel is in a stationary state, and calculate the theoretical rotation angle of the steering wheel according to a preset angle ratio parameter;

[0030] According to the radius of the chessboard and the distance between the midpoint and the edge of the chessboard in the current captured image parallel to the driving ground, the current actual rotation angle of the steering wheel is obtained, and the difference between the theoretical rotation angle and the actual rotation angle is calculated as the rotation angle error between the steering wheel and the steering actuator in the steering function test result.

[0031] Optionally, the test result unit further includes the following subunits:

[0032] An alignment unit in communication with the parameter comparison unit is configured to obtain a rotation angle error between the steering wheel and the steering actuator when the steering actuator rotates left and right by the same angle;

[0033] The difference between the two errors is calculated as the alignment error in the steering function test result, and when the alignment error is greater than a preset threshold, it is determined that the left-right alignment is abnormal.

[0034] Another aspect of the present invention provides an electromagnetic compatibility test method for intelligent connected vehicle steering by wire, the method being applied to an electromagnetic compatibility test system for intelligent connected vehicle steering by wire, comprising:

[0035] Sending a steering command to the steering actuator so that the steering actuator performs a steering operation according to the received steering command;

[0036] Collecting a chessboard image captured by a camera, the camera is fixedly connected to the vehicle, and captures an image of a complete chessboard along the axle direction of the steering wheel. The chessboard is circular and its midpoint coincides with the midpoint of the steering wheel, and is fixed to the outside of the steering wheel;

[0037] The steering function test result is obtained according to the steering situation of the steering actuator and the change of the outline of the chessboard in the image.

[0038] Optionally, obtaining a steering function test result according to a steering condition of the steering actuator and a change in a chessboard outline in an image includes:

[0039] Generate a steering command based on steering data input by a user and send it to a steering actuator, wherein the steering data includes steering speed, steering angle, step time and dwell time;

[0040] After receiving the shooting command, the camera is controlled to continuously shoot images of the chessboard and store each image and the shooting time;

[0041] Get the steering wheel The starting time of the turn and stop time , and obtain The distance L between the midpoint and the edge of the chessboard in the corresponding image parallel to the driving ground, and The distance M between the midpoint and edge of the chessboard in the corresponding image parallel to the driving ground is calculated according to the following formula: The actual turning angle of the secondary steering :

[0042]

[0043] in, , is the total number of steering wheels turning during the test;

[0044] Collect steering actuator The starting time of the turn action and stop time , and the actual steering angle , and according to the steering wheel The starting time of the turn , Stop time and the actual rotation angle , obtaining a steering function test result, wherein the steering function test result at least includes a steering angle error and a steering delay.

[0045] An electromagnetic compatibility test system and method for wire-controlled steering of intelligent connected vehicles disclosed in an embodiment of the present invention can solve the technical conflicts that prevent the implementation of precise black box testing of wire-controlled steering of intelligent connected vehicles, and provide a test system and method with strong adaptability that can be deployed in an electromagnetic compatibility darkroom. By controlling the steering actuator on the steering wheel, the vehicle steering system is manipulated to rotate to a set angle at a set angular velocity, and the image of the chessboard deployed on the outside of the steering wheel is collected by a camera. Based on the processor, the image is analyzed to obtain information such as the actual steering angle, and the steering function test result is obtained. The vehicle-level wire-controlled steering test is realized, and a new test guarantee solution is provided for the safe operation of the wire-controlled steering system of intelligent connected vehicles. The test system and method disclosed in the present invention have the advantages of high adaptability, low cost, and convenient deployment. It is suitable for autonomous driving vehicles with various sensor architectures and function / scenario definitions, has extremely high industrial application value, and can meet the current and future wire-controlled steering test and evaluation needs.

[0046] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0048] Figure 1 A schematic diagram of the structure of an electromagnetic compatibility test system for intelligent connected vehicle steer-by-wire provided by an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of the structure of a processor subunit provided by an embodiment of the present invention;

[0050] Figure 3 A schematic diagram of a change in a chessboard outline in an image provided by an embodiment of the present invention;

[0051] Figure 4 A schematic diagram of an actual rotation angle of a steering wheel provided in an embodiment of the present invention;

[0052] Figure 5 A steering comparison diagram between a steering actuator and a steering wheel provided in an embodiment of the present invention;

[0053] Figure 6 A schematic flow chart of an electromagnetic compatibility testing method for steering-by-wire of an intelligent connected vehicle provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0054] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0055] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0056] The vehicle's steer-by-wire system eliminates the direct connection between traditional mechanics and hydraulics, and no longer uses physical components between the steering wheel and the wheels to achieve steering, but relies entirely on electrical signals to transmit steering commands. In the embodiments disclosed in the present invention, electromagnetic compatibility (EMC) test equipment is used to simulate electromagnetic interference that the vehicle may encounter in actual operation, so as to detect the performance of the steer-by-wire system in an electromagnetic environment.

[0057] Figure 1 The present invention provides a schematic diagram of the structure of an electromagnetic compatibility test system for intelligent connected vehicle steer-by-wire, which is used to test the steer-by-wire function of a vehicle in an electromagnetic environment. Figure 1 As shown, the test system includes a steering actuator 1 , a checkerboard 2 , a camera 3 and a processor 4 .

[0058] 1. Steering actuator

[0059] In the embodiment disclosed in the present invention, the steering actuator 1 is installed on the steering wheel and is responsible for performing the corresponding steering operation according to the received steering command. For example, the tester transmits the steering signal to the processor 4. After receiving the steering signal, the processor 4 combines other data (such as vehicle speed, road conditions, etc.) to perform signal processing and calculation to generate an optimized steering command, which is sent to the steering actuator 1 to instruct it to generate a corresponding rotation, thereby driving the steering wheel to rotate.

[0060] (II) Chessboard

[0061] In the embodiment disclosed in the present invention, the chessboard 2 is a circular mark with a uniformly distributed black and white checkered pattern, fixed to the outside of the steering wheel, the midpoint of the chessboard 2 coincides with the midpoint of the steering wheel, and the radius of the chessboard 2 is smaller than the radius of the steering wheel.

[0062] The pattern on the chessboard 2 can provide multiple symmetrical feature points, which is convenient for high-precision image recognition and measurement. The chessboard 2 is arranged outside the steering wheel, and its radius is smaller than that of the steering wheel, which can ensure that it can rotate synchronously with the steering wheel.

[0063] The center point of the chessboard 2 coincides precisely with the center point of the steering wheel, that is, the center points of the two overlap in a plane parallel to the outer side of the steering wheel. The circular structure of the chessboard 2 ensures that the rotation angle in all directions can be measured consistently, avoiding errors caused by irregular shapes.

[0064] (III) Camera

[0065] In the embodiment disclosed in the present invention, the camera 3 is fixed to the vehicle body and can capture the image of the complete chessboard 2 along the axle direction of the steering wheel.

[0066] In a specific implementation disclosed in the present invention, the camera 3 is a high-speed camera, which can capture the subtle changes of the checkerboard 2 in the image when the wheel rotates at a very high frame rate, ensuring accurate measurement data collection.

[0067] The center point of the optical axis of the camera 3 is located on the extension line of the axle direction, ensuring that the center of the chessboard 2 image is aligned with the center of the steering wheel, which not only enables the rotation angle change of the steering wheel to be accurately captured, but also facilitates the analysis of the deformation of the chessboard 2 through the image processing algorithm.

[0068] Under the capture of the high-resolution camera 3, the edge of the chessboard 2 can reflect the rotation angle of the steering wheel. When the steering wheel rotates, the chessboard 2 image captured by the camera 3 will be deformed accordingly, for example, into an ellipse. The actual rotation angle of the steering wheel can be calculated by the degree of deformation.

[0069] In the embodiment disclosed in the present invention, a circular chessboard 2 is arranged on the outer side of each steering wheel, and each steering wheel corresponds to a camera 3 that can shoot the complete chessboard 2 thereon, so as to implement the test of each steering wheel. Since the test content of each steering wheel is exactly the same, in the embodiment disclosed in the present invention, only the steering test process of one steering wheel is described, and the test content of the other steering wheels is not repeated.

[0070] 4. Processor

[0071] The processor 4 is communicatively connected with the steering actuator 1 and the camera 3, and can send steering instructions to the steering actuator 1, collect the checkerboard image taken by the camera 3, and obtain the steering function test result according to the steering condition of the steering actuator 1 and the contour change of the checkerboard 2 in the image.

[0072] In one embodiment disclosed in the present invention, Figure 2 As shown, the processor 4 includes a steering instruction unit 41 , an image unit 42 , an analysis unit 43 and a test result unit 44 .

[0073] 1. Steering command unit

[0074] The steering command unit 41 is connected to the steering actuator 1 in communication, and can generate a steering command according to the steering data input by the tester, and send it to the steering actuator 1, wherein the steering data includes steering speed, steering angle, step time and dwell time. For example, the steering speed is ω, the steering angle is θ, the step time is △T1, and the dwell time is △T2. The intention of the steering command is to make the vehicle turn θ at the steering speed of ω and drive for △T1 time, and then stop for △T2 time.

[0075] 2. Image Unit

[0076] The image unit 42 is in communication with the camera 3 and is used to control the camera 3 to continuously capture images of the chessboard 2 after receiving a capture instruction, store the images transmitted by the camera 3, and record the capture time of each image.

[0077] Immediately after receiving the shooting instruction, the imaging unit 42 activates the camera 3 to put it in a continuous shooting mode. This mode can capture the chessboard image at a specified frame rate in a short time, ensuring that the captured image can reflect the real-time state of the chessboard 2. For example, the camera 3 quickly and multiple times captures the image of the chessboard 2 at a small time interval.

[0078] The image unit 42 monitors each frame of the image captured by the camera 3 in real time, and records the shooting time of each image to form an "image-timestamp" pair. This allows accurate tracking of the changes in the chessboard 2 during the steering process, especially when shooting at a high frequency, to capture every tiny deformation of the chessboard 2 in the image.

[0079] The imaging unit 42 stores the continuously captured image data together with the corresponding time stamps and transmits them to the analysis unit.

[0080] 3. Analysis Unit

[0081] The analysis unit 43 is in communication with the image unit 42 and is used to obtain the start time and the end time of each steering action completed by the steering wheel.

[0082] Steering wheel Taking the first turn as an example, the starting time can be obtained by the following method and stop time :

[0083] The outline of the checkerboard 2 in the image is continuously monitored. For example, the outline of the checkerboard 2 can be detected by measuring the distance between the midpoint and the edge of the checkerboard 2 in the image parallel to the driving surface.

[0084] Determine whether the stability time of the outline of the chessboard 2 in the image changes after exceeding the first preset time, that is, determine whether the steering wheel starts to turn, and if so, take the time when the change occurs as the starting time , and continue to determine whether the outline of the chessboard 2 in the image stops changing, and whether the stable time after stopping the change exceeds the second preset time, that is, determine whether the steering wheel completes the steering action. If so, the moment of stopping the change is taken as the termination moment , wherein the first preset time length and the second preset time length are both a relatively short time period, and the purpose is to determine whether the steering wheel is in the process of steering. For example, the first preset time length and the second preset time length can both be 100 milliseconds. If the steering wheel does not turn for more than 100 milliseconds, but starts to turn at a certain moment, this moment is taken as the starting moment; if the steering wheel does not turn again within 100 milliseconds after stopping turning, the moment when the steering stops is taken as the termination moment.

[0085] like Figure 3 As shown, in determining the steering wheel The starting time and stop time After that, In the corresponding image, measure the distance L between the midpoint O of the chessboard 2 and the edge parallel to the driving ground, and In the corresponding image, the distance M between the midpoint O of the chessboard 2 and the edge parallel to the driving ground is measured, such as Figure 4 As shown, the steering wheel is calculated according to the following formula The actual turning angle of the secondary steering :

[0086]

[0087] in, , is the total number of steering wheel turns during the test.

[0088] 4. Test results unit

[0089] The test result unit 44 is respectively connected to the analysis unit 43 and the steering actuator 1 for communication, and is used to collect the start time and the stop time of each rotation of the steering actuator 1 .

[0090] Steering Actuator 1 Taking the first turn as an example, the sensor on the steering actuator 1 is used to obtain the starting time of the steering of the steering actuator 1. , Stop time and actual steering angle , and according to the steering wheel The starting time of the turn , Stop time and the actual rotation angle , obtaining a steering function test result, the steering function test result at least including a steering angle error and a steering delay.

[0091] In the embodiment disclosed in the present invention, the test result unit 44 includes a steering angle error unit and a steering delay unit.

[0092] 4-1. Steering angle error unit

[0093] The steering angle error unit is used to The actual rotation angle after the first turn, and the steering actuator 1 The actual steering angle after the first steering action is calculated as After the second turn, the relative steering actuator 1 .

[0094]

[0095] The magnitude of the steering angle error can reflect the synchronization of the steering function. When the error is small, it indicates that there is good consistency between the steering actuator 1 and the steering wheel; if the error is large, it indicates that the response of the steering wheel may be delayed, friction or electromagnetic interference.

[0096] 4-2. Steering delay unit

[0097] The steering delay unit is used to The start and end time of the second turn, as well as the first The start and end time of the steering action are calculated. Steering delay relative to steering actuator 1 after the second steering.

[0098] In the embodiment disclosed in the present invention, the test content of the steering system may be: the vehicle moves forward for ΔT time after turning, and then stops for the same ΔT time, and this is repeated multiple times, for example, 10 times, and the test result of each time is analyzed.

[0099] In order to understand the test results intuitively, in the embodiments disclosed in the present invention, Figure 5As shown, the steering comparison diagram between the steering actuator 1 and the steering wheel is drawn in the following manner:

[0100] With the sampling time as the horizontal axis and the rotation angle as the vertical axis, a curve of the steering actuator 1 (represented by a solid line) and a curve of the steering wheel (represented by a dotted line) are plotted.

[0101] Depend on Figure 5 It can be seen that in the first steering process, the steering actuator 1 (indicated by the dotted line) rotates to an angle of θ within the time of 0~T, and then maintains the angle for △T. The steering wheel (indicated by the solid line) rotates to an angle of Ф within the time of 0-t1. At this point, it can be calculated that in the first steering process, the steering delay of the steering wheel relative to the steering actuator 1 is t1-T. By analogy, the corresponding steering delay can be calculated for each steering process thereafter.

[0102] The steering delay unit is also used to screen out the maximum steering delay according to the steering delay of each steering of the steering wheel, and calculate the average steering delay, and use the maximum steering delay and the average steering delay as a steering function test result.

[0103] In an embodiment disclosed in the present invention, the test result unit further includes a parameter comparison unit.

[0104] 4-3. Parameter comparison unit

[0105] The parameter comparison unit is connected to the vehicle speed sensor on the vehicle for obtaining the actual turning angle of the steering wheel and the actual steering angle of the steering actuator 1 for each set vehicle speed when the steering actuator 1 receives the same steering command at multiple set vehicle speeds, and calculating the actual steering ratio at the set vehicle speed according to the following formula:

[0106]

[0107] For example, multiple target speeds (such as low, medium, and high) are set, and the vehicle is able to execute the same steering command at different speeds. The actual steering ratio is calculated for each target speed.

[0108] The actual steering ratio at each set vehicle speed is compared with the corresponding preset steering ratio parameter (the steering ratio parameter is set by the vehicle manufacturer, for example, the corresponding steering ratio parameter at low speed is A, the corresponding steering ratio parameter at medium speed is B, and the corresponding steering ratio parameter at high speed is C), and the difference between the actual steering ratio and the steering ratio parameter is calculated as the steering ratio error in the steering function test result.

[0109] By setting different vehicle speeds, the actual steering ratio at different speeds is calculated and compared with the steering parameters set by the vehicle manufacturer to determine whether the steering ratio adjustment function is affected by the electromagnetic environment.

[0110] In one embodiment disclosed in the present invention, the parameter comparison unit is also connected to the steering actuator 1 for obtaining the current rotation angle of the steering actuator 1 when the vehicle speed is fixed or the vehicle is stopped, that is, the angle of rotation of the steering actuator 1 compared with its set 0 degree. The theoretical rotation angle of the steering wheel is calculated according to the angle ratio parameter preset by the vehicle manufacturer (that is, the ratio between the steering wheel rotation angle and the steering wheel rotation angle). For example, if the steering wheel is rotated 1 degree and is expected to drive the steering wheel to rotate 0.5 degrees, the theoretical rotation angle of the steering wheel = the current angle of the steering wheel × 0.5.

[0111] According to the radius of the chessboard 2 and the distance between the midpoint and the edge of the chessboard 2 in the current captured image parallel to the driving ground, the current actual rotation angle of the steering wheel is obtained, and the difference between the theoretical rotation angle and the actual rotation angle is calculated as the rotation angle error between the steering wheel and the steering actuator 1 in the steering function test result.

[0112] When the vehicle speed is fixed or stationary, the angle data of the steering actuator 1 on the steering wheel is mathematically calculated with the parameters of the vehicle manufacturer to obtain the theoretical rotation angle of the steering wheel, which is compared with the actual rotation angle of the steering wheel to obtain the rotation angle error.

[0113] In one embodiment disclosed in the present invention, the test result unit further includes an alignment unit.

[0114] 4-4. Alignment unit

[0115] The alignment unit is in communication with the parameter comparison unit, and is used to obtain a rotation angle error between the steering wheel and the steering actuator 1 when the steering actuator 1 rotates leftward and rightward by the same angle starting from a set 0 degree.

[0116] The alignment unit receives the rotation angle error data calculated by the parameter comparison unit. When the steering actuator 1 rotates to the left and right to the same angle respectively, the parameter comparison unit calculates the rotation angle error between the steering actuator 1 and the steering wheel to obtain the left turn error and the right turn error respectively.

[0117] The alignment unit compares the left turn error and the right turn error and calculates the difference between the two. The difference is the alignment error, which is used to reflect whether the left and right steering systems maintain consistent response characteristics.

[0118] The alignment unit compares the calculated alignment error with the system preset alignment error threshold. If the alignment error value exceeds the threshold, it is determined that the alignment of the left and right steering is abnormal, indicating that the response characteristics of the left and right steering are inconsistent.

[0119] Figure 6The present invention discloses a flow chart of an electromagnetic compatibility test method for a smart connected vehicle steering by wire, which is applied to the electromagnetic compatibility test system for a smart connected vehicle steering by wire disclosed in the above embodiments. Figure 6 As shown, the method comprises the following steps:

[0120] Step S100: sending a steering instruction to the steering actuator, so that the steering actuator performs a steering operation according to the received steering instruction.

[0121] Step S200: Acquire a chessboard image captured by a camera, the camera is fixedly connected to the vehicle, and captures an image of a complete chessboard along the axle direction of the steering wheel. The chessboard is circular and its midpoint coincides with the midpoint of the steering wheel, and is fixed to the outside of the steering wheel.

[0122] Step S300: Obtaining a steering function test result according to the steering condition of the steering actuator and the change of the outline of the chessboard in the image.

[0123] The content of the test method can be found in the above-mentioned embodiment and will not be repeated here.

[0124] In one embodiment disclosed in the present invention, step S300 may be completed in the following manner.

[0125] (1) Generate steering instructions based on the steering data input by the user and send them to the steering actuator. The steering data includes steering speed, steering angle, step time, and dwell time.

[0126] (2) After receiving the shooting command, the camera is controlled to continuously shoot images of the chessboard and store each image and the shooting time.

[0127] (3) Obtain the steering wheel The starting time of the turn and stop time , and obtain The distance L between the midpoint and the edge of the chessboard in the corresponding image parallel to the driving ground, and The distance M between the midpoint and edge of the chessboard in the corresponding image parallel to the driving ground is calculated according to the following formula: The actual turning angle of the secondary steering .

[0128]

[0129] in, , is the total number of steering wheels turning during the test;

[0130] (4) Collect the steering actuator The starting time of the turn action and stop time , and the actual steering angle , and according to the steering wheel The starting time of the turn , Stop time and the actual rotation angle , obtaining a steering function test result, the steering function test result at least including a steering angle error and a steering delay.

[0131] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An electromagnetic compatibility test system for intelligent connected vehicle steering by wire, characterized in that: Applicable to testing the vehicle's steer-by-wire function in an electromagnetic environment, the test system includes: A steering actuator fixed to the steering wheel is configured to perform a steering operation according to a received steering command; A circular chessboard fixed to the outer side of the steering wheel, wherein the midpoint of the chessboard coincides with the midpoint of the steering wheel; A camera fixedly connected to the vehicle, configured to capture an image of a complete chessboard along the axle direction of the steering wheel; A processor in communication with the steering actuator and the camera, configured to send a steering instruction to the steering actuator, collect a checkerboard image captured by the camera, and obtain a steering function test result according to a steering condition of the steering actuator and a change in a checkerboard contour in the image; The processor includes a steering instruction unit that is communicatively connected to the steering actuator, and is configured to generate a steering instruction according to steering data input by a user, and send the steering instruction to the steering actuator, wherein the steering data includes a steering speed ω, a steering angle θ, a step time △T1, and a dwell time △T2, so that the vehicle turns at a steering speed of ω by an angle θ and then drives for a time period of △T1, and then stops for a time period of △T2, and repeats multiple times; The processor also includes the following units: The image unit is connected to the camera in communication, and is configured to control the camera to continuously capture images of the chessboard after receiving a capture instruction, and store each image and the capture time; The analysis unit, which is in communication with the image unit, is configured to obtain the starting time of the i-th turning of the steering wheel. and stop time And, get The distance L between the midpoint and the edge of the chessboard in the corresponding image parallel to the driving ground, and The distance M between the midpoint and edge of the chessboard in the corresponding image parallel to the driving ground is calculated according to the following formula: i : Where, 1≤i≤n, n is the total number of steering wheels turned during the test; The test result unit is respectively connected to the analysis unit and the steering actuator in communication, and is configured to collect the starting time of the steering actuator performing the steering action for the i-th time. and stop time And the actual steering angle Φ i , and according to the starting time of the i-th steering wheel Stop time and the actual rotation angle θ i , obtaining a steering function test result, wherein the steering function test result at least includes a steering angle error and a steering delay.

2. The test system according to claim 1, characterized in that: The radius of the chessboard is smaller than the radius of the steering wheel.

3. The test system according to claim 1, characterized in that: The camera is a high-speed camera, and the center point of the optical axis is located on the extension line of the axle direction.

4. The test system according to claim 1, characterized in that: The test result unit includes the following subunits: A steering angle error unit is configured to calculate a steering angle error of the steering wheel relative to the steering actuator after the i-th steering according to an actual rotation angle of the steering wheel after the i-th steering and an actual steering angle after the steering actuator performs the i-th steering action; A steering delay unit is configured to calculate a steering delay of the steering wheel relative to the steering actuator after the i-th steering according to the start time and the stop time of the i-th steering of the steering wheel and the start time and the stop time of the i-th steering action performed by the steering actuator; The steering delay unit is further configured to obtain a maximum steering delay and an average steering delay according to a steering delay of each steering of the steering wheel.

5. The test system according to claim 1, characterized in that: The test result unit also includes the following subunits: The parameter comparison unit, which is in communication connection with the vehicle speed sensor on the vehicle, is configured to obtain the actual turning angle of the steering wheel and the actual steering angle of the steering actuator for each set vehicle speed when the steering actuator receives the same steering instruction at multiple set vehicle speeds, and calculate the actual steering ratio at the set vehicle speed according to the following formula: The actual steering ratio at each set vehicle speed is compared with the corresponding preset steering ratio parameter, and the difference between the actual steering ratio and the steering ratio parameter is calculated as the steering ratio error in the steering function test result.

6. The test system according to claim 5, characterized in that: The parameter comparison unit is also in communication with the steering actuator and is configured to obtain the current rotation angle of the steering actuator when the steering wheel is in a stationary state, and calculate the theoretical rotation angle of the steering wheel according to a preset angle ratio parameter; According to the radius of the chessboard and the distance between the midpoint and the edge of the chessboard in the current captured image parallel to the driving ground, the current actual rotation angle of the steering wheel is obtained, and the difference between the theoretical rotation angle and the actual rotation angle is calculated as the rotation angle error between the steering wheel and the steering actuator in the steering function test result.

7. The test system according to claim 6, characterized in that: The test result unit also includes the following subunits: An alignment unit in communication with the parameter comparison unit is configured to obtain a rotation angle error between the steering wheel and the steering actuator when the steering actuator rotates left and right by the same angle; The difference between the two errors is calculated as the alignment error in the steering function test result, and when the alignment error is greater than a preset threshold, it is determined that the left-right alignment is abnormal.

8. A method for testing electromagnetic compatibility of intelligent connected vehicle steering by wire, characterized in that: The method is applied to the electromagnetic compatibility test system for intelligent connected vehicle steer-by-wire according to any one of claims 1 to 7, comprising: Sending a steering command to the steering actuator so that the steering actuator performs a steering operation according to the received steering command; Collecting a chessboard image captured by a camera, wherein the camera is fixedly connected to the vehicle and captures an image of a complete chessboard along the axle direction of the steering wheel; the chessboard is circular and its midpoint coincides with the midpoint of the steering wheel, and is fixed to the outer side of the steering wheel; The steering function test results are obtained based on the steering situation of the steering actuator and the changes in the outline of the chessboard in the image, including: Generate a steering command based on the steering data input by the user and send it to the steering actuator. The steering data includes the steering speed ω, the steering angle θ, the step time △T1 and the dwell time △T2, so that the vehicle turns the angle θ at the steering speed ω and drives for △T1 time, then stops for △T2 time, and repeats multiple times; After receiving the shooting command, the camera is controlled to continuously shoot images of the chessboard and store each image and the shooting time; Get the starting time of the i-th turning of the steering wheel and stop time And, get The distance L between the midpoint and the edge of the chessboard in the corresponding image parallel to the driving ground, and The distance M between the midpoint and edge of the chessboard in the corresponding image parallel to the driving ground is calculated according to the following formula: i : Where, 1≤i≤n, n is the total number of steering wheels turned during the test; Collect the starting time of the steering actuator's i-th steering action and stop time And the actual steering angle Φ i , and according to the starting time of the i-th steering wheel Stop time and the actual rotation angle θ i , obtaining a steering function test result, wherein the steering function test result at least includes a steering angle error and a steering delay.

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