Wheel rotation angle zero offset estimation method and system, storage medium and vehicle terminal
By installing inertial measurement units and navigation units on vehicles, the zero-bias error of wheel rotation angle is automatically measured, solving the problems of high cost and low efficiency in traditional calibration, and realizing efficient and low-cost zero-bias calibration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUIZHOU DESAY SV AUTOMOTIVE
- Filing Date
- 2024-11-30
- Publication Date
- 2026-06-02
AI Technical Summary
In existing technologies, wheel angle measurement has a zero-bias error, which leads to wear on the tires and steering mechanism. Furthermore, traditional zero-bias calibration relies on manual operation, which is costly and inefficient.
By installing inertial measurement units and navigation units on the vehicle's steering knuckle and body, and combining the data from the navigation unit, the actual turning angle of the wheels relative to the vehicle body is automatically measured, the zero-bias error is calculated, and automated calibration is achieved.
It reduced calibration costs, improved calibration efficiency, reduced manual intervention, adapted to different types of vehicles, and improved the accuracy and reliability of the system.
Smart Images
Figure CN122130032A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of calibration technology, and in particular to a zero-bias estimation method, system, storage medium and vehicle terminal for wheel rotation angle. Background Technology
[0002] Currently, intelligent driving is gradually replacing the driver's role. To facilitate manual control, trucks in the current transportation sector still retain a front-wheel steering chassis structure, meaning that during turns, the front wheels of the vehicle turn while the rear wheels remain stationary. In the era of driverless vehicles, transportation will transform into flatbed trucks without a driver's cab. This type of vehicle will no longer have a cab; multiple freely rotating wheels will be installed under the cargo bed, enabling more flexible steering and greater maneuverability in narrower and more complex road conditions.
[0003] This type of multi-wheel steering chassis places higher demands on the accuracy of wheel angle measurement. Poor coordination between wheel angles can lead to rapid wear on the tires and steering mechanism. Currently, wheel rotation mechanisms are mostly achieved by electro-hydraulic cylinders or motors with rack and pinion mechanisms. Wheel angle measurement is essentially the measurement of the displacement of the rack or hydraulic cylinder. However, machining and assembly errors in the hydraulic cylinder or rack and pinion mechanism can cause zero-offset errors in the wheel.
[0004] Traditional zero-offset calibration typically requires manual operation by specialized maintenance or assembly workers, which is costly and time-consuming. Furthermore, for cargo vehicles, wear on the steering mechanism during operation causes the zero-position error of each wheel to gradually change over time, necessitating periodic calibration, further highlighting the high cost and low efficiency of manual calibration. Summary of the Invention
[0005] To address the aforementioned technical problems, this application provides an automated method, system, storage medium, and vehicle-mounted terminal for zero-bias estimation of wheel steering angle.
[0006] Specifically, this application provides a zero-bias estimation method for wheel steering angle, which pre-installs an inertial measurement unit and a navigation unit on the steering knuckle and / or vehicle body of the current vehicle. The zero-bias estimation method for wheel steering angle includes the following steps:
[0007] The navigation unit acquires the position coordinates of each inertial measurement unit and the rotation angle signal of each wheel.
[0008] The operation data of the inertial measurement unit and the navigation unit are acquired to obtain an angle sequence set based on the position coordinates and the operation data.
[0009] Furthermore, based on the included angle sequence set, the actual turning angle sequence set of each wheel of the current vehicle relative to the vehicle body is obtained, and the turning angle zero deviation error of each wheel is obtained based on the actual turning angle sequence set and the turning angle signal.
[0010] The above technical solution achieves automated calibration without manual intervention, reducing calibration costs and improving calibration efficiency. Only the inertial measurement unit and navigation unit need to be pre-installed to achieve automatic calibration with zero bias error throughout the entire life cycle of the vehicle. It eliminates the need for professional maintenance personnel with complex tools to perform calibration at after-sales service points on a regular basis, further demonstrating that the zero bias estimation method for wheel angle of this application can improve calibration efficiency and reduce calibration costs.
[0011] Furthermore, it also includes: pre-installing the wheels of the current vehicle onto the steering knuckle; wherein the steering knuckle is connected to the control arm or half shaft via a kingpin.
[0012] Furthermore, the inertial measurement unit is installed at a first preset position on the main pin and the vehicle body, and the navigation unit is installed at a second preset position on the vehicle body.
[0013] In the above technical solution, by installing an inertial measurement unit and a navigation unit on the steering knuckle and the vehicle body respectively, and combining the data from the navigation unit, the actual turning angle of the wheel relative to the vehicle body can be accurately measured. Then, by comparing it with the turning angle of the wheel relative to the vehicle body output by the original vehicle, the zero-bias error of the turning angle of the wheel measured by the original vehicle can be obtained.
[0014] Furthermore, obtaining the location coordinates includes:
[0015] The relative positions of the navigation unit and each inertial measurement unit are obtained, so as to obtain the position coordinates based on the relative positions.
[0016] In the above technical solution, obtaining position coordinates through relative position can better realize the fusion of multi-sensor data, improve the comprehensive utilization effect of data, and further improve the calibration accuracy.
[0017] Furthermore, acquiring the operational data includes:
[0018] Based on set conditions, positioning data and status data of the navigation unit and inertial measurement unit under various operating conditions are collected as the operating data; wherein, the status data includes at least acceleration and angular velocity.
[0019] In the above technical solution, by collecting data under various working conditions, the operating status of the vehicle under different operating conditions can be fully covered, thereby more accurately analyzing and calibrating the wheel angle.
[0020] Further, obtaining the included angle sequence set includes:
[0021] The included angle sequence set is calculated based on the positioning data, acceleration, angular velocity, and position coordinates; wherein the included angle sequence set includes a first included angle and multiple second included angles, the first included angle being the angle between the inertial measurement unit installed on the vehicle body and a set direction, and the second included angle being the angle between the inertial measurement unit installed on the steering knuckle and the set direction.
[0022] In the above technical solution, by comprehensively utilizing positioning data, acceleration, angular velocity and position coordinates, the angle between each wheel and the set direction can be accurately calculated, that is, the actual turning angle between the wheel and the vehicle body.
[0023] Furthermore, obtaining the zero-bias error of the rotation angle includes:
[0024] The actual turning angle sequence set is obtained based on the difference between each second included angle and the first included angle, so as to obtain the initial zero bias error of each wheel based on the actual turning angle sequence set and the turning angle signal.
[0025] In the above technical solution, the system's adaptability to different types of vehicles is enhanced by calculation based on the actual turning angle sequence set and turning angle signal, and it can be widely applied to various transport vehicles; through accurate initial zero bias error calculation, the system error caused by turning angle error can be reduced, thereby improving the system's accuracy and reliability.
[0026] Furthermore, obtaining the zero-offset error of the rotation angle also includes:
[0027] The initial zero bias error is filtered to obtain the corner zero bias error.
[0028] In the above technical solution, filtering can effectively eliminate noise and outliers in the initial zero bias error, and improve the accuracy of the final angle zero bias error. Filtering can smooth the fluctuation of error, reduce the error abrupt change caused by instantaneous noise, and improve the continuity and stability of the system output.
[0029] Based on the same concept, this application also provides a zero-bias estimation system for wheel steering angle, which pre-installs an inertial measurement unit and a navigation unit on the steering knuckle and / or body of the current vehicle, the system comprising:
[0030] The acquisition unit is used to acquire the position coordinates of the navigation unit based on each of the inertial measurement units, as well as the rotation angle signal of each wheel.
[0031] The calculation unit is used to acquire the operating data of the inertial measurement unit and the navigation unit, so as to obtain the angle sequence set based on the position coordinates and the operating data.
[0032] And, a calibration unit, used to obtain the actual turning angle sequence set of each wheel of the current vehicle relative to the vehicle body according to the included angle sequence set, and to obtain the turning angle zero deviation error of each wheel based on the actual turning angle sequence set and the turning angle signal.
[0033] In the above technical solution, through high-precision data acquisition, dynamic analysis and accurate zero-bias error calculation, the system achieves automated calibration, which reduces labor costs and improves calibration efficiency.
[0034] In addition, this system can adapt to different types and models of vehicles and is widely used in various transport vehicles, demonstrating strong adaptability and versatility.
[0035] Based on the same concept, this application also provides a storage medium storing a computer program, wherein the computer program is configured to execute the zero-bias estimation method for wheel angle at runtime.
[0036] Based on the same concept, this application also provides a vehicle-mounted terminal, which includes a processor and a memory. The memory stores at least one instruction, at least one program, code set, or instruction set. The at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the zero-bias estimation method for wheel angle.
[0037] Compared with the prior art, the beneficial effects of this application are as follows:
[0038] This application pre-installs inertial measurement units (IMUs) and navigation units on the steering knuckles and / or body of the current vehicle. It then acquires the position coordinates of the navigation units based on the IMUs, as well as the steering angle signals of each wheel. Next, it acquires the operational data of the IMUs and navigation units to obtain an angle sequence set based on the position coordinates and operational data. Further, it obtains the actual steering angle sequence set of each wheel relative to the vehicle body based on the angle sequence set, and then obtains the zero-bias error of each wheel's steering angle based on the actual steering angle sequence set and the steering angle signals. This application achieves automated calibration without manual intervention, reducing calibration costs and improving calibration efficiency. Attached Figure Description
[0039] Figure 1 This is a flowchart of the zero-bias estimation method for wheel rotation angle described in this application.
[0040] Figure 2 This is a schematic diagram showing the installation position of the wheel in this application.
[0041] Figure 3 This is a schematic diagram showing the installation positions of the inertial measurement unit and navigation unit described in this application.
[0042] Figure 4 This is a framework diagram of the zero-bias estimation system for wheel rotation angle described in this application. Detailed Implementation
[0043] The following describes in further detail, with reference to specific embodiments and accompanying drawings, a method, system, storage medium, and vehicle terminal for zero-bias estimation of wheel rotation angle according to this application.
[0044] Please see Figure 1 This application provides a zero-bias estimation method for wheel steering angle, which pre-installs an inertial measurement unit and a navigation unit on the steering knuckle and / or vehicle body of the current vehicle.
[0045] Please see below. Figure 2 The wheels of the current vehicle need to be pre-installed on the steering knuckle; wherein the steering knuckle is connected to the swing arm or half shaft via a kingpin.
[0046] In some embodiments, the steering wheel is mounted on the steering knuckle via a bearing, and the steering knuckle is connected to the swing arm (independent suspension) or half-shaft (non-independent suspension) via a kingpin; therefore, the wheel mounted on the steering knuckle can rotate about the kingpin relative to the swing arm or half-shaft, while the swing arm or half-shaft does not rotate relative to the front of the vehicle.
[0047] Among them, the control arm is responsible for transmitting various forces (such as vertical force, lateral force and braking force) from the wheel to the frame or body to ensure that the wheel can drive normally; the control arm in the independent suspension system allows the wheel to move in the vertical and lateral directions to adapt to uneven road surfaces and provide better driving comfort.
[0048] The half-shaft is responsible for transmitting the engine's torque from the differential to the wheels, driving the wheels to rotate. In a non-independent suspension system, the half-shaft also serves to support the wheels, and is mounted on the steering knuckle via bearings. In a non-independent suspension system, the half-shaft, together with the steering knuckle, allows the wheels to move vertically to adapt to uneven road surfaces.
[0049] In addition, it should be noted that the inertial vehicle unit is the IMU (Inertial Measurement Unit), and the navigation unit is the GNSS (Global Navigation Satellite System).
[0050] Those skilled in the art may also choose other centimeter-level global positioning systems as the navigation unit according to the actual application scenario, and are not limited to this.
[0051] And, please see Figure 3 The inertial measurement unit is installed at a first preset position on the main pin and the vehicle body, and the navigation unit is installed at a second preset position on the vehicle body.
[0052] In some embodiments, the inertial measurement unit is installed at the kingpin position where the steering knuckle is connected to the control arm or half shaft. When machining the steering knuckle, a fixing groove for the inertial measurement unit needs to be reserved to ensure that the longitudinal axis of the inertial measurement unit is parallel to the plane of the wheel installed on the steering knuckle. In this way, the rotation angle of the longitudinal axis of the inertial measurement unit relative to the vehicle body is equal to the rotation angle of the wheel relative to the vehicle body.
[0053] In addition to installing the inertial measurement units on the steering knuckles of each wheel, an inertial vehicle unit and a navigation unit capable of centimeter-level global positioning also need to be installed on the vehicle body. It is necessary to ensure that the longitudinal axis of the inertial measurement unit installed on the vehicle body coincides with the longitudinal axis of the vehicle frame, and that the antenna of the navigation unit is fixed to the vehicle position.
[0054] Furthermore, the vehicle body is also equipped with a data processing and recording unit for implementing some or all of the steps of the various embodiments of this application; the inertial measurement units installed on each wheel, the inertial measurement unit installed on the vehicle body, the navigation unit that provides centimeter-level positioning, and the wheel angle sensor that outputs wheel angle signals from the original vehicle are all connected to the data processing and recording unit via signal lines.
[0055] In the above technical solution, by installing an inertial measurement unit and a navigation unit on the steering knuckle and the vehicle body respectively, and combining the data from the navigation unit, the actual turning angle of the wheel relative to the vehicle body can be accurately measured. Then, by comparing it with the turning angle of the wheel relative to the vehicle body output by the original vehicle, the zero-bias error of the turning angle of the wheel measured by the original vehicle can be obtained.
[0056] Specifically, the zero-bias estimation method for the wheel steering angle includes the following steps:
[0057] Step S100: Obtain the position coordinates of the navigation unit based on each of the inertial measurement units, and the rotation angle signal of each wheel.
[0058] Obtaining the position coordinates includes:
[0059] The relative positions of the navigation unit and each inertial measurement unit are obtained, so as to obtain the position coordinates based on the relative positions.
[0060] In some embodiments, after the installation of each component is completed according to the requirements described above, the relative positional relationship between the IMU installed on each steering knuckle and the antenna of the GNSS system is measured; wherein, the measurement includes:
[0061] Using a high-precision measuring tool (such as a laser tracker), the position of the inertial measurement unit on each steering knuckle is measured sequentially, and the coordinates of each inertial measurement unit (relative to a fixed reference point) are recorded; using the same high-precision measuring tool, the position of the navigation unit is measured, and the coordinates of the navigation unit (relative to the same fixed reference point) are recorded.
[0062] Furthermore, the relative positional relationship between the inertial measurement unit and the navigation unit on each steering knuckle is calculated to obtain the coordinates of the navigation unit in the coordinate system of each inertial measurement unit.
[0063] Wherein, the coordinates of the navigation unit in the coordinate system of the inertial measurement unit = the coordinates of the navigation unit - the coordinates of the inertial measurement unit.
[0064] In the above technical solution, obtaining position coordinates through relative position can better realize the fusion of multi-sensor data, improve the comprehensive utilization effect of data, and further improve the calibration accuracy.
[0065] Furthermore, the steering angle signals {θ} of each wheel output by the wheel steering angle sensor m1 ,θ m2 ,θ m3 ,…θ mn}; where the steering angle signal is the steering angle measurement signal output by the original vehicle.
[0066] Step S200: Obtain the operating data of the inertial measurement unit and the navigation unit, so as to obtain the angle sequence set based on the position coordinates and the operating data.
[0067] The acquisition of the operational data includes:
[0068] Based on set conditions, positioning data and status data of the navigation unit and inertial measurement unit under various operating conditions are collected as the operating data; wherein, the status data includes at least acceleration and angular velocity.
[0069] In some embodiments, the data processing and recording unit collects data on the vehicle under various operating conditions, including straight driving, right-angle left turn, right-angle right turn, acceleration, and deceleration. During the data collection process, the maximum vehicle speed during straight driving needs to be higher than 30 km / h (i.e., the set condition), and it is confirmed that the navigation unit's positioning can reach the centimeter level.
[0070] It should be noted that those skilled in the art can also set other settings according to actual application needs, and are not limited to this.
[0071] In addition, during the data acquisition process, the data processing and recording unit monitors the data quality in real time to ensure that the navigation unit achieves centimeter-level positioning accuracy.
[0072] This can be achieved by collecting navigation unit positioning data multiple times at the same or different locations, comparing the results of multiple measurements, calculating the repeatability error, and then evaluating the consistency and accuracy of the multiple measurements.
[0073] In other embodiments, those skilled in the art may employ other monitoring methods to ensure the accuracy of the navigation unit, and are not limited to these.
[0074] Furthermore, the operational data includes positioning data from the navigation unit, and acceleration and angular velocity output from inertial measurement units on each steering knuckle and the vehicle body.
[0075] In the above technical solution, by collecting data under various working conditions, the operating status of the vehicle under different operating conditions can be fully covered, thereby more accurately analyzing and calibrating the wheel angle.
[0076] Further, obtaining the included angle sequence set includes:
[0077] The included angle sequence set is calculated based on the positioning data, acceleration, angular velocity, and position coordinates; wherein the included angle sequence set includes a first included angle and multiple second included angles, the first included angle being the angle between the inertial measurement unit installed on the vehicle body and a set direction, and the second included angle being the angle between the inertial measurement unit installed on the steering knuckle and the set direction.
[0078] In some embodiments, combining the centimeter-level positioning data provided by the navigation unit, the acceleration and angular velocity provided by each inertial measurement unit, and the initially obtained position coordinates of the navigation unit based on each of the inertial measurement units, the Kalman filter algorithm of the strapdown inertial navigation system can be used to calculate the angle between the longitudinal axis of each inertial measurement unit and geographic north, recorded as {h1, h2, h3, ... h n ,h b}
[0079] Among them, h b (i.e., the first included angle) is the angle between the longitudinal axis of the inertial measurement unit mounted on the chassis and the geographic north direction, h1, h2, h3, ... h n (i.e., the second included angle) are the included angles between the longitudinal axis of the inertial measurement unit installed on the 1st to nth steering knuckles and the geographic north direction.
[0080] Specifically:
[0081] Initialize the state vector of the Kalman filter, which includes a first angle and a second angle, and initialize the covariance matrix of the Kalman filter.
[0082] Furthermore, based on the angular velocity, the state vector and covariance matrix of the next moment are predicted using a strapdown inertial navigation algorithm, and the measurement vector is calculated based on the position coordinates and positioning data. The Kalman gain is calculated based on the covariance matrix and the measurement vector. Then, the state vector and covariance matrix are updated based on the Kalman gain and the covariance matrix of the predicted state vector.
[0083] Furthermore, the final first and second included angles are obtained from the updated state vector.
[0084] In the above technical solution, by comprehensively utilizing positioning data, acceleration, angular velocity, and position coordinates, the angle between each wheel and the vehicle body can be accurately calculated; by comprehensively utilizing multiple data sources, the impact of errors from a single data source on the overall result can be reduced, thereby improving the accuracy of calibration.
[0085] Step S300: Obtain the actual turning angle sequence set of each wheel of the current vehicle relative to the vehicle body according to the included angle sequence set, and obtain the turning angle zero deviation error of each wheel based on the actual turning angle sequence set and the turning angle signal.
[0086] Furthermore, obtaining the zero-bias error of the rotation angle includes:
[0087] The actual turning angle sequence set is obtained based on the difference between each second included angle and the first included angle, so as to obtain the initial zero bias error of each wheel based on the actual turning angle sequence set and the turning angle signal.
[0088] In some embodiments, h1, h2, h3, ... h n Subtract h b This yields the actual turning angle {θ} of each wheel relative to the vehicle body. a1 ,θ a2 ,θ a3 ,…θ an}, θ for each wheel at each moment a The rotation angle signal θ given by the rotation angle sensor m Subtracting these values yields the zero-bias error θ of the steering angle sensor for each wheel. bias .
[0089] In the above technical solution, the system's adaptability to different types of vehicles is enhanced by calculation based on the actual turning angle sequence set and turning angle signal, and it can be widely applied to various transport vehicles; through accurate initial zero bias error calculation, the system error caused by turning angle error can be reduced, thereby improving the system's accuracy and reliability.
[0090] Furthermore, obtaining the zero-offset error of the rotation angle also includes:
[0091] The initial zero bias error is filtered to obtain the corner zero bias error.
[0092] In some embodiments, by using θ at multiple times bias After filtering, a stable zero-bias error value (i.e., the angle zero-bias error) can be obtained. At this time, the zero-bias error is written into the data processing and recording unit.
[0093] In other embodiments, θ can also be used at multiple times. bias The mean value is calculated to obtain the accurate value in the least squares sense, which is taken as the zero-bias error of the rotation angle.
[0094] In the above technical solution, filtering can effectively eliminate noise and outliers in the initial zero bias error, and improve the accuracy of the final angle zero bias error. Filtering can smooth the fluctuation of error, reduce the error abrupt change caused by instantaneous noise, and improve the continuity and stability of the system output.
[0095] Furthermore, based on the same concept, this application also provides a zero-bias estimation system for wheel steering angle, which pre-installs an inertial measurement unit and a navigation unit on the steering knuckle and / or vehicle body of the current vehicle. The system includes:
[0096] The acquisition unit is used to acquire the position coordinates of the navigation unit based on each of the inertial measurement units, as well as the rotation angle signal of each wheel.
[0097] The calculation unit is used to acquire the operating data of the inertial measurement unit and the navigation unit, so as to obtain the angle sequence set based on the position coordinates and the operating data.
[0098] And, a calibration unit, used to obtain the actual turning angle sequence set of each wheel of the current vehicle relative to the vehicle body according to the included angle sequence set, and to obtain the turning angle zero deviation error of each wheel based on the actual turning angle sequence set and the turning angle signal.
[0099] In some embodiments, the zero-bias estimation system for the wheel angle is equivalent to Figure 3 The data processing and recording unit in the middle.
[0100] At the beginning of vehicle assembly, inertial measurement units need to be installed on the steering knuckles of each wheel, as well as an inertial measurement unit on the vehicle body. A navigation unit capable of centimeter-level global positioning also needs to be installed at a preset position on the vehicle body, preferably using a GNSS system.
[0101] In this configuration, the steering wheel is typically mounted on the steering knuckle via a bearing. The steering knuckle is connected to the control arm (in independent suspension) or half-shaft (in non-independent suspension) via a kingpin. Therefore, the wheel mounted on the steering knuckle can rotate relative to the control arm or half-shaft around the kingpin, while the control arm or half-shaft does not rotate relative to the front of the vehicle. An inertial measurement unit (IMU) is installed at the kingpin position where the steering knuckle connects to the control arm. During the machining of the steering knuckle, a mounting groove for the IMU is pre-drilled to ensure that the longitudinal axis of the IMU is parallel to the plane of the wheel mounted on the steering knuckle. This ensures that the rotation angle of the IMU's longitudinal axis relative to the vehicle body is equal to the rotation angle of the wheel relative to the vehicle body.
[0102] It should be noted that the longitudinal axis of the inertial measurement unit installed on the vehicle body must be aligned with the longitudinal axis of the vehicle frame, and the navigation unit must be fixed in position with the vehicle.
[0103] In the above technical solution, through high-precision data acquisition, dynamic analysis and accurate zero-bias error calculation, the system achieves automated calibration, which reduces labor costs and improves calibration efficiency.
[0104] In addition, this system can adapt to different types and models of vehicles and is widely used in various transport vehicles, demonstrating strong adaptability and versatility.
[0105] Furthermore, based on the same concept, this application also provides a storage medium storing a computer program, wherein the computer program is configured to execute the zero-bias estimation method for the wheel angle at runtime.
[0106] In some embodiments, the storage medium stores several computer programs to cause an in-vehicle terminal to perform all or part of the steps of the methods described in various embodiments of this application.
[0107] The medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.
[0108] Furthermore, based on the same concept, this application also provides a vehicle-mounted terminal, which includes a processor and a memory. The memory stores at least one instruction, at least one program, code set, or instruction set. The at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the zero-bias estimation method for wheel angle.
[0109] In some embodiments, the memory and the processor are interconnected via a bus; the processor may be one or more CPUs. If the processor is a single CPU, it may be a single-core CPU or a multi-core CPU. The processor is used to control the various functional modules of the vehicle terminal and process signals.
[0110] The memory includes, but is not limited to, RAM (Random Access Memory), ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), and CD-ROM (Compact Disc Read-Only Memory). This memory is used to store computer programs, operating systems, various applications, and data, such as storing a computer program for implementing the zero-bias estimation method for the wheel angle.
[0111] In summary, this application provides a method, system, storage medium, and vehicle-mounted terminal for zero-bias estimation of wheel steering angles. It pre-installs inertial measurement units (IMUs) and navigation units on the steering knuckles and / or body of the current vehicle. Then, it acquires the position coordinates of the navigation units based on the IMUs, as well as the steering angle signals of each wheel. Next, it acquires the operating data of the IMUs and navigation units to obtain an angle sequence set based on the position coordinates and operating data. Further, it obtains the actual steering angle sequence set of each wheel relative to the vehicle body based on the angle sequence set, and obtains the zero-bias error of each wheel's steering angle based on the actual steering angle sequence set and the steering angle signals. This application achieves automated calibration without manual intervention, reducing calibration costs and improving calibration efficiency.
[0112] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.
[0113] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0114] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.
[0115] The various component embodiments of this application can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules according to the embodiments of this application. This application can also be implemented as an apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such an implementation of this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.
[0116] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0117] Although the description of this application has been made in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.
Claims
1. A zero-bias estimation method for wheel rotation angle, characterized in that, The zero-bias estimation method for wheel steering angle, which pre-installs an inertial measurement unit and a navigation unit on the steering knuckle and / or body of the current vehicle, includes the following steps: The navigation unit acquires the position coordinates of each inertial measurement unit and the rotation angle signal of each wheel. The operation data of the inertial measurement unit and the navigation unit are acquired to obtain an angle sequence set based on the position coordinates and the operation data; Furthermore, based on the included angle sequence set, the actual turning angle sequence set of each wheel of the current vehicle relative to the vehicle body is obtained, and the turning angle zero deviation error of each wheel is obtained based on the actual turning angle sequence set and the turning angle signal.
2. The zero-bias estimation method for wheel rotation angle according to claim 1, characterized in that, Also includes: The wheels of the current vehicle are pre-installed on the steering knuckle; wherein the steering knuckle is connected to the swing arm or half shaft via a kingpin; and the inertial measurement unit is installed at a first preset position on the kingpin and the vehicle body, and the navigation unit is installed at a second preset position on the vehicle body.
3. The zero-bias estimation method for wheel rotation angle according to claim 1, characterized in that, Obtaining the position coordinates includes: obtaining the relative positions of the navigation unit and each inertial measurement unit, so as to obtain the position coordinates based on the relative positions.
4. The zero-bias estimation method for wheel rotation angle according to claim 3, characterized in that, Acquiring the operational data includes: collecting positioning data and status data of the navigation unit and inertial measurement unit under various operating conditions based on set conditions, as the operational data; The state data includes at least acceleration and angular velocity.
5. The zero-bias estimation method for wheel rotation angle according to claim 4, characterized in that, Obtaining the included angle sequence set includes: The included angle sequence set is calculated based on the positioning data, acceleration, angular velocity, and position coordinates. The included angle sequence set includes a first included angle and multiple second included angles. The first included angle is the angle between the inertial measurement unit installed on the vehicle body and the set direction, and the second included angle is the angle between the inertial measurement unit installed on the steering knuckle and the set direction.
6. The zero-bias estimation method for wheel rotation angle according to claim 5, characterized in that, Obtaining the zero-offset error of the rotation angle includes: The actual turning angle sequence set is obtained based on the difference between each second included angle and the first included angle, so as to obtain the initial zero bias error of each wheel based on the actual turning angle sequence set and the turning angle signal.
7. The zero-bias estimation method for wheel rotation angle according to claim 6, characterized in that, Obtaining the zero-offset error of the rotation angle further includes: The initial zero bias error is filtered to obtain the corner zero bias error.
8. A system employing the zero-bias estimation method for wheel rotation angle as described in any one of claims 1-7, characterized in that, The system includes an inertial measurement unit and a navigation unit pre-installed on the steering knuckle and / or body of the current vehicle. The acquisition unit is used to acquire the position coordinates of the navigation unit based on each of the inertial measurement units, and the rotation angle signal of each wheel; A calculation unit is used to acquire the operating data of the inertial measurement unit and the navigation unit, so as to obtain an angle sequence set based on the position coordinates and the operating data; And, a calibration unit, used to obtain the actual turning angle sequence set of each wheel of the current vehicle relative to the vehicle body according to the included angle sequence set, and to obtain the turning angle zero deviation error of each wheel based on the actual turning angle sequence set and the turning angle signal.
9. A storage medium, characterized in that, The storage medium stores a computer program, wherein the computer program is configured to execute the zero-bias estimation method for wheel angle as described in any one of claims 1-7 when it is run.
10. A vehicle-mounted terminal, characterized in that, The vehicle-mounted terminal includes a processor and a memory. The memory stores at least one instruction, at least one program, a code set, or an instruction set. The at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the zero-bias estimation method for wheel angle as described in any one of claims 1-7.