Vehicle sensor calibration tool and system

Abstract

The utility model relates to the field of sensor calibration, in particular to a vehicle sensor calibration tool and system. The vehicle sensor calibration tool comprises a base fixing device; the at least one sensor base is used for bearing a sensor to be calibrated, the sensor base is mounted on the base fixing device, and the sensor base has a plurality of degrees of freedom of motion; and the control device is connected with the sensor base and controls the sensor base to drive the sensor to be calibrated to move to a target position, and the target position is determined based on the position of the sensor to be calibrated in the vehicle.

Description

Technical Field

[0001] This disclosure relates to the field of sensor calibration, specifically to a sensor calibration fixture and system for a vehicle. Background Technology

[0002] Sensor calibration refers to establishing the correspondence between the sensor's output and input quantities through experiments, and determining the error relationship under different operating conditions. The purpose of calibration is to correct the sensor's errors and make it as accurate as possible, thereby ensuring its measurement accuracy and stability under various operating conditions.

[0003] In the field of intelligent driving, vehicle sensor calibration is fundamental. Incorrect sensor calibration can lead to algorithms failing to accurately reflect actual results, resulting in safety hazards. In the actual development of mass-produced vehicles, the development of calibration algorithms often requires modification of existing vehicles to verify their functionality. However, mass production typically begins in the later stages of a project. Therefore, the development and verification of calibration algorithms necessitates modifications to existing vehicles. Once mass-produced prototypes begin production, the algorithm must be re-adapted and verified, resulting in a lengthy development cycle and high costs, as each vehicle model requires a new vehicle modification. Furthermore, updates to sensor design locations, calibration boards, and calibration algorithms all require modifications and alterations to both the vehicle and the calibration board to verify the latest calibration algorithm. Utility Model Content

[0004] This disclosure provides a sensor calibration fixture and system for vehicles, which can solve the problems of high sensor calibration cost and poor flexibility in vehicles.

[0005] In a first aspect, embodiments of this application provide a sensor calibration fixture for a vehicle, comprising:

[0006] Base fixing device;

[0007] At least one sensor base for supporting the sensor to be calibrated, the sensor base being mounted on the base fixing device, the sensor base having multiple degrees of freedom of motion;

[0008] A control device is connected to the sensor base and controls the sensor base to move the sensor to be calibrated to a target position, the target position being determined based on the position of the sensor to be calibrated in the vehicle.

[0009] Optionally, the sensor base includes a base, a motion mechanism, and a base body. The sensor base is connected to the base fixing device via the base. The motion mechanism is disposed on the base and has multiple degrees of freedom. The motion mechanism includes at least one of a translation mechanism and a rotation mechanism. The translation mechanism is a mechanism that drives the base body to translate along a coordinate axis, and the rotation mechanism is a mechanism that drives the base body to rotate around a coordinate axis. The base body is disposed on the motion mechanism and is provided with a connection mechanism for fixing the sensor to be calibrated.

[0010] Optionally, the base fixing device is a box, and the sensor base is fixed on the inner wall of the box.

[0011] Optionally, the ratio of the internal space dimensions of the housing to the dimensions of the vehicle is N.

[0012] Optionally, the control device is configured to control the sensor base to move the sensor to be calibrated to the target position represented by the second target coordinates based on the first target coordinates of the sensor to be calibrated;

[0013] Wherein, the first target coordinate is the position coordinate in the vehicle coordinate system, and the second target coordinate is the position coordinate in the box coordinate system. The second target coordinate is obtained by performing coordinate transformation on the first target coordinate with a set coefficient, which is determined based on the ratio between the size parameters of the box and the size parameters of the vehicle.

[0014] Optionally, the sensor to be calibrated is a camera sensor, and the calibration fixture further includes at least one calibration plate, which is disposed on the side wall or bottom plate inside the housing.

[0015] Optionally, the housing has multiple grooves on its inner wall, and the sensor base is disposed in the grooves.

[0016] Optionally, the control device is also connected to the sensor to be calibrated, and the control device calibrates the sensor to be calibrated based on the sensing signal sent by the sensor to be calibrated.

[0017] Secondly, embodiments of this application provide a vehicle sensor calibration system, including: a sensor to be calibrated and a calibration fixture as described in any of the first aspects, wherein the number of sensor bases corresponds one-to-one with the number of sensors to be calibrated;

[0018] A region controller is communicatively connected to the sensor to be calibrated. The region controller is used to receive the sensing signals sent by the sensor to be calibrated and to calibrate the sensor based on the sensing signals.

[0019] Optionally, the area controller is communicatively connected to the control device, the control device receives sensor signals and calibration results based on the communication connection, and the control module is configured to verify the calibration results based on the sensor signals and calibration algorithm.

[0020] One beneficial effect of this disclosure is that the calibration fixture includes a base fixing device, on which a sensor base is provided to support at least the sensor to be calibrated. A control device can control the sensor base to translate or rotate in multiple directions to move the sensor to the target position for calibration. In this way, when calibrating vehicle sensors, it is not necessary to install the sensor on the actual vehicle. The user only needs to control the sensor to reach the target position via the control device to calibrate the sensor. Furthermore, if the sensor's designed position in the vehicle changes, only the sensor base needs to be adjusted to move the sensor to the new target position for calibration, without modifying the actual vehicle. This solves the problems of high cost and poor flexibility in vehicle sensor calibration.

[0021] Other features and advantages of the embodiments of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the embodiments of the present disclosure.

[0023] Figure 1 A structural block diagram of a sensor calibration fixture for a vehicle according to an embodiment of the present disclosure is shown;

[0024] Figure 2 A schematic diagram of a sensor base according to an embodiment of the present disclosure is shown;

[0025] Figure 3 A schematic diagram of the base fixing device according to an embodiment of the present disclosure is shown;

[0026] Figure 4 A schematic diagram of the housing according to an embodiment of this disclosure is shown;

[0027] Figure 5 A structural block diagram of a sensor calibration system for a vehicle according to an embodiment of the present disclosure is shown. Detailed Implementation

[0028] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0029] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0030] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0031] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0033] It should be noted that all actions involving the collection, storage, use, processing, transmission, provision, disclosure, and deletion of data in this disclosure are carried out in accordance with the relevant data protection laws and regulations of the country or region where the data is located, and with the full authorization of the relevant data owner.

[0034] like Figure 1 As shown in the embodiment of this application, a sensor calibration fixture 100 for a vehicle is described, including a base fixing device 101; at least one sensor base 102 for carrying a sensor to be calibrated, the sensor base being mounted on the base fixing device and having multiple degrees of freedom of motion; and a control device 103 connected to the sensor base, which controls the sensor base to move the sensor to be calibrated to a target position, the target position being determined based on the position of the sensor to be calibrated in the vehicle.

[0035] The vehicle in this application may be a vehicle that is in production and has an actual vehicle, or it may be a vehicle that is not in production and is in the design stage.

[0036] In this embodiment of the application, the calibration fixture may be provided with one or more sensor bases, such as Figure 2 As shown, Figure 2This is a simplified schematic diagram of a sensor base. The sensor base can have functions similar to a robotic arm, capable of translation or rotation in multiple directions. A sensor to be calibrated can be mounted on the sensor base, such as a camera, accelerometer, radar sensor, etc. In one example, the sensor base can be a three-degree-of-freedom or six-degree-of-freedom sensor base.

[0037] In this embodiment of the application, the calibration fixture is further provided with a base fixing device, which can be used to fix the sensor base. In one example, such as Figure 3 As shown, the base mounting device can be a simple vehicle frame. In one example, the vehicle frame can be built based on the sensor type and common calibration algorithms. For instance, when the sensor is a camera sensor, the camera position of the vehicle camera is usually relatively fixed, and may include front and rear fisheye or binocular fisheye, left and right rear side-view, left and right front side-view, left fisheye, right fisheye, front wide-angle, front narrow-angle, or rear-view cameras, etc. Therefore, when building the base mounting device, frames can be built near the corresponding camera positions to fix the sensor bases. In this example, the corresponding positions of the base mounting device can be provided with clips or other fixing mechanisms to fix one or more sensor bases to the base mounting device. Figure 3 For example, in Figure 3 In the vehicle frame 10, six sensor bases are fixed. Sensor bases 11 and 12 can be used to install a front fisheye camera in the direction of the vehicle's front. Sensor bases 13 and 14 can be used to install cameras such as left rear-view, right rear-view, left front-view, and right front-view cameras near the vehicle's rearview mirrors. Sensor base 15 is used to install a front wide-angle or front narrow-angle camera on the front side of the roof. Sensor base 16 is used to install a rear-view camera on the rear side of the roof.

[0038] In another example, the base mounting device can be a housing. The sensor base can be mounted on the inner or outer surface of the housing.

[0039] In this embodiment, the calibration fixture also includes a control device that can control the movement of the sensor base, i.e., translation or rotation in multiple directions, thereby moving the sensor on the base to a target position. In this example, the target position corresponds to the position of the sensor to be calibrated in the vehicle. The position can be determined based on the vehicle's design. In this example, the control device can control the sensor base by inputting the coordinates of the target position, or linearly controlling the movement of the sensor base through interactive controls such as a joystick or virtual operation buttons.

[0040] With the calibration fixture in this embodiment, when calibrating vehicle sensors, it is not necessary to install the sensors on a real vehicle for calibration. The user only needs to control the sensor to reach the target position through the control device to achieve sensor calibration. At the same time, if the sensor setting position changes, only the sensor base needs to be adjusted to recalibrate without modifying the real vehicle, thus solving the problems of high cost and poor flexibility of vehicle sensor calibration.

[0041] In one example of this embodiment, the sensor base includes a base, a motion mechanism, and a base body. The sensor base is connected to a base fixing device via the base. The motion mechanism is disposed on the base and has multiple degrees of freedom of motion. The motion mechanism includes at least one of a translation mechanism and a rotation mechanism. The translation mechanism is a mechanism that drives the base body to translate along a coordinate axis, and the rotation mechanism is a mechanism that drives the base body to rotate around a coordinate axis. The base body is disposed on the motion mechanism and is provided with a connection mechanism for fixing the sensor to be calibrated.

[0042] In one example, a multi-degree-of-freedom sensor base can be as follows: Figure 2 As shown, the device includes a base 4 for connection with a base fixing device. A motion mechanism is connected to the base 4. The motion mechanism may include multiple motors 2 and connecting rods 3. The motors and connecting rods act as translation or rotation mechanisms and move or rotate under the control of the control module, thereby adjusting the position and orientation of the sensor to be calibrated. In this example, a base body 1 is also provided on the motion mechanism. The base body 1 can be used to fix the sensor to be calibrated.

[0043] In this example, this method allows each sensor to move within a certain range, avoiding frequent removal of the sensor base from the mounting device, and enabling the test fixture to calibrate sensors for more types of vehicles.

[0044] The base fixing device can also be a box, with the sensor base fixed to the inner wall of the box.

[0045] In this example, the base fixing device can also be configured as a housing, which acts as the vehicle's outer shell, providing a fixed foundation for the sensor base. This allows those skilled in the art to position it as needed, enabling the calibration of sensors at various locations within the vehicle. The housing can be a rectangular, enclosed enclosure, such as... Figure 4 As shown, one or more sensor bases can be fixed on the inner wall of the housing. In this example, the sensor can be moved to the target position by adjusting the motion mechanism in each sensor base for calibration.

[0046] In this embodiment, the ratio of the internal space dimensions of the box to the vehicle dimensions is N.

[0047] In this embodiment, to reduce the footprint of the calibration fixture, the internal space of the housing within the fixture can be determined using the dimensions of the vehicle to be tested. Specifically, the vehicle's length, width, and height can be scaled down proportionally, for example, by a 1:10 ratio, to obtain the internal dimensions of the housing before constructing the housing. In another example, the ratio of the internal dimensions of the housing to the vehicle dimensions can be 1. That is, a proportionally scaled housing is constructed as the vehicle, housing the sensor to be calibrated. Alternatively, the ratio of the internal dimensions of the housing to the vehicle dimensions can be greater than 1, such as 1.5, 2, or larger. In other words, the internal dimensions of the housing can be an enlarged version of the vehicle dimensions. By setting a larger dimension, other objects needed for calibrating the sensor, such as calibration plates, can be placed within the internal space of the housing.

[0048] In another example, the internal dimensions of the box, such as length, width, and height, can be the vehicle dimensions scaled down by a preset ratio, with an additional length added according to actual needs to leave some margin.

[0049] In one example of this embodiment, the control device is configured to control the sensor base to move the sensor to be calibrated to a target position represented by a second target coordinate, based on the first target coordinate of the sensor to be calibrated; wherein, the first target coordinate is the position coordinate in the vehicle coordinate system, and the second target coordinate is the position coordinate in the box coordinate system. The second target coordinate is obtained by performing coordinate transformation on the first target coordinate with a set coefficient, and the set coefficient is determined based on the ratio between the size parameters of the box and the size parameters of the vehicle.

[0050] In the technical solution of this application, when calibrating sensors in a vehicle using calibration fixtures, the user can directly input the sensor's position coordinates in the vehicle coordinate system into the control device. In this field, the vehicle coordinate system is typically defined with the midpoint of the line connecting the rear wheel of the vehicle to the ground plane as the origin, the forward direction of the vehicle body as the X-axis, the leftward direction of the vehicle body as the Y-axis, and the vertically upward direction as the Z-axis. The first target coordinates can be predetermined based on the actual situation of the vehicle and the expected installation design. Afterwards, the control device can transform the position coordinates of the sensor to be calibrated in the vehicle coordinate system to the housing coordinate system and control it to move to the target position.

[0051] In one example, the control module can determine the ratio of the vehicle's dimensions to the box's dimensions, and use this ratio as a setpoint to transform the coordinates between the vehicle coordinate system and the box coordinate system. For example, the ratios between the vehicle's length and the box's length, the vehicle's height and the box's height, and the vehicle's width and the box's width can be determined separately, and then the setpoint can be set to a value greater than the maximum of these three ratios. For instance, if the length ratio of the vehicle to the box is 10, the height ratio is 9, and the width ratio is 8, then the setpoint can be set to a value greater than or equal to 10.

[0052] In this example, the first target coordinates are converted to the second target coordinates according to a set coefficient, which can be achieved by dividing the first target coordinates by the set coefficient. In this way, since the set coefficient is set to a value greater than or equal to 10, the reduction ratio of the second target coordinates to the first target coordinates is larger than the ratio of the vehicle to the box. This allows for some margin in the length, width, and height directions inside the box. That is, the coordinates of any position on the vehicle body in the vehicle coordinate system can be converted to the box coordinate system and fall within the internal space of the box. At the same time, some margin allows for the installation of calibration plates or other calibration equipment inside the box, enabling the calibration fixture to calibrate more types of sensors.

[0053] In this embodiment, the origin of the box coordinate system can be a position within the box that corresponds to the origin of the vehicle coordinate system, determined by those skilled in the art based on the box size parameters and the vehicle's length, width, height, and other dimensional parameters, along with set coefficients. Alternatively, it can be a position pre-set by those skilled in the art based on actual testing requirements.

[0054] In one example of this embodiment, the sensor to be calibrated is a camera sensor, and the calibration fixture also includes at least one calibration plate, which is disposed on the side wall or bottom plate inside the housing.

[0055] In this example, the sensor to be calibrated is a camera sensor. During the calibration process, camera sensors typically require a channel calibration board to assist in correcting lens distortion, determining physical dimensions and pixel conversion relationships, and establishing the relationship between the three-dimensional geometric position of a point on the surface of a spatial object and its corresponding point in the image. The calibration board can be a solid circular array pattern calibration board, a checkerboard calibration board, or a CharuCo calibration board, etc. In this example, considering that vehicle cameras typically only need to capture images of the surrounding area and the ground, the calibration board can be placed on the side wall or bottom plate inside the housing.

[0056] In another example, the enclosure could be constructed of a transparent material to accommodate situations where the interior space of the enclosure is not suitable for containing the calibration plate.

[0057] In one example of this embodiment, for the box coordinate system, the size of the calibration plate can also be set proportionally based on a set coefficient. When the set coefficient is 1, that is, when the size parameter of the space inside the box is greater than or equal to the vehicle size parameter, the size of the calibration plate can be the normal size. When the set coefficient is 10, it means that the box has been scaled. At this time, the size of the calibration plate can also be scaled proportionally, reduced by 10 times.

[0058] In one example of this embodiment, the inner wall of the housing is provided with multiple grooves, and the sensor base is disposed in the grooves. In one example, the shape of the grooves may be the same as the shape of the base of the sensor base.

[0059] In one example of this embodiment, the control device is also connected to the sensor to be calibrated, and the control device calibrates the sensor to be calibrated based on the sensing signal sent by the sensor to be calibrated.

[0060] In this embodiment, the control module can also connect to each sensor to be calibrated and acquire the data collected by the sensor according to the connection. Simultaneously, the control module can pre-store a calibration algorithm to calibrate the sensor based on the acquired data. In another example, the control module also has a display unit that can display the data collected by the sensor, such as images captured by a camera sensor, thereby intuitively demonstrating the sensor calibration process and results.

[0061] In one example of this embodiment, a vehicle sensor calibration system 1000 is also described, such as... Figure 5 As shown, the calibration fixture 100 includes: a calibration fixture 110 for a sensor to be calibrated and a vehicle sensor, wherein the number of sensor bases corresponds one-to-one with the number of sensors to be calibrated; and a region controller 120, which is communicatively connected to the sensor to be calibrated. The region controller is used to receive the sensing signals sent by the sensor to be calibrated and to calibrate the sensor to be calibrated based on the calibration algorithm and the sensing signals.

[0062] In this embodiment, the number of sensor bases in the system can be set based on the number of sensors to be calibrated. The specific type and model of the area controller can be selected based on the actual situation or design of the vehicle, and the same model can be selected to simulate a real vehicle for testing. A communication connection is established between the area controller and the sensors to be calibrated, allowing the acquisition of sensor signals. Simultaneously, the area controller pre-stores sensor calibration algorithms, and based on these algorithms and the sensor signals, it can calibrate the sensors to be calibrated.

[0063] In one example of this embodiment, the area controller is communicatively connected to the control module. The control module receives sensor signals and calibration results based on the communication connection. The control module is configured to verify the calibration results based on the sensor signals and the calibration algorithm.

[0064] In this example, the domain controller also communicates with the control module, which can be a computer, mobile phone, tablet, or other computing device or terminal. The communication connection between the two can be wireless or wired. Based on this communication connection, the domain controller can send the sensor signals and calibration results to the control module. The control module can also pre-store the calibration algorithm and verify the calibration results through the calibration algorithm. If there are no problems with the calibration results, the sensor calibration is considered complete.

[0065] The various embodiments in this disclosure are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and apparatus embodiments are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0066] The above embodiments mainly focus on the differences from other embodiments, but those skilled in the art should understand that the above embodiments can be used alone or in combination as needed.

[0067] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A sensor calibration fixture for a vehicle, characterized in that, include: Base fixing device; At least one sensor base for supporting the sensor to be calibrated, the sensor base being mounted on the base fixing device, the sensor base having multiple degrees of freedom of motion; A control device is connected to the sensor base and controls the sensor base to move the sensor to be calibrated to a target position, the target position being determined based on the position of the sensor to be calibrated in the vehicle; The sensor base includes a base, a motion mechanism, and a base body. The sensor base is connected to the base fixing device via the base. The motion mechanism is disposed on the base and has multiple degrees of freedom. The motion mechanism includes at least one of a translation mechanism and a rotation mechanism. The translation mechanism is a mechanism that drives the base body to translate along a coordinate axis, and the rotation mechanism is a mechanism that drives the base body to rotate around a coordinate axis. The base body is disposed on the motion mechanism and is provided with a connection mechanism for fixing the sensor to be calibrated. The base fixing device is provided with a fixing mechanism for fixing one or more sensor bases to the base fixing device.

2. The calibration fixture according to claim 1, characterized in that, The base fixing device is a box, and the sensor base is fixed on the inner wall of the box.

3. The calibration fixture according to claim 2, characterized in that, The ratio of the internal space dimensions of the box to the dimensions of the vehicle is N.

4. The calibration fixture according to claim 2, characterized in that, The sensor to be calibrated is a camera sensor, and the calibration fixture also includes at least one calibration plate, which is disposed on the side wall or bottom plate inside the housing.

5. The calibration fixture according to claim 2, characterized in that, Multiple grooves are provided on the inner wall of the housing, and the sensor base is disposed in the grooves.

6. A calibration system for vehicle sensors, characterized in that, include: The sensor to be calibrated and the calibration fixture according to any one of claims 1-5, wherein the number of sensor bases corresponds one-to-one with the number of sensors to be calibrated.

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