Angle detection method in a steering system

Abstract

This invention provides a steering system angle sensing method that addresses the problem of requiring the installation direction of a single-sided S / N bipolar magnet to be a 0° magnetic field. [Solution] A magnetic angle sensor is set up to detect the magnetic field angle from at least one magnet on a rotating component or driven gear, and outputs an absolute angle value. After initialization, the first absolute angle is recorded as the starting angle. The current relative angle is calculated based on the relationship between the current absolute angle and the starting absolute angle to determine the direction of rotation and the number of turns. The relative angle, direction, and rotation are used to calculate the precise rotation angle and direction of the main rotating component or gear. If the system starts from a component that is not 0°, the system retrieves the rotation data stored since the last shutdown and applies offset compensation to correct the angle. This method eliminates the need to consider the orientation of the magnets, improving flexibility.

Description

[Technical Field]

[0001] The present invention relates to a steering system angle sensing method, and more specifically, to a steering system angle sensing method that can convert absolute angles to relative angles, determine the direction of rotation and the cumulative number of turns, thereby enabling the calculation of the final angle between 0 and 360 degrees, or to continuously maintain the cumulative calculation of the steering angle based on the periodic definition in generalized trigonometric functions, beyond the 360-degree limit. [Background technology]

[0002] Steering angle sensors are widely used in vehicle steering systems to detect the steering angle of an automobile's steering wheel, enabling related systems (such as body control modules and electronic stability control systems) to understand the steering angle and implement corresponding safety control strategies.

[0003] Specifically, the steering angle sensor uses a single-sided S / N bipolar magnet embedded in one or more small gears. It detects changes in the magnetic field angle during gear rotation (0° to 360°) and calculates the current steering wheel rotation angle based on the gear ratio between the main gear (steering column) and the small gears. To ensure that the initial steering angle of the steering wheel is 0° when the steering angle sensor is activated, it is essential that the system provides an unbiased reading of the steering wheel's steering angle after startup. Therefore, the installation direction of the single-sided S / N bipolar magnet and its coordination with the gear are crucial during the sensor's manufacturing and assembly process. Not only must the magnet's installation direction be aligned with the 0° magnetic field, but the gear must also be installed so that the steering angle of the main gear aligns with the steering angle position of the steering wheel. This assembly process significantly complicates the manufacturing of the steering angle sensor and typically requires additional angle positioning tools and fixtures to ensure installation accuracy, thereby increasing manufacturing costs. To simplify this process and reduce assembly errors, manufacturers of vehicle steering systems may opt for more expensive angle sensors with automatic zero calibration capabilities, which handle the angle zero positioning problem entirely in hardware. However, the development and production costs of such sensors are also high.

[0004] Therefore, in relation to increasingly complex automotive electronic systems, the development of economical and highly accurate angle sensing solutions is a critical challenge in this industry. [Overview of the Initiative]

[0005] Therefore, the present invention primarily provides a steering system angle sensing method that does not require special calibration or adjustment of the orientation of a single-sided SN bipolar magnet to a 0° magnetic field during manufacturing and assembly. This method ensures that the output angle is 0° when the steering component or driven gear is in a centered state, thereby providing an economical and highly accurate angle sensing solution.

[0006] Embodiments of the present invention disclose a steering system angle sensing method for sensing the rotation of one or more rotating components in a steering system, each of which is composed of a magnet. The steering system comprises a main gear connected to a steering shaft, one or more driven gears meshing with the main gear, one or more magnets positioned on each of the one or more driven gears, one or more magnetic angle sensors each configured to sense the magnetic field angle generated by the one or more magnets and to output one or more absolute angle values, a processing unit, and a storage unit coupled to the processing unit, which stores program code instructing the processing unit to execute the steering system angle sensing method, and enables sensing the rotation of the one or more rotating components or driven gears using the one or more magnetic angle sensors, wherein the steering system angle sensing method includes the steps of recording one or more first sets of absolute angle values ​​between 0 degrees and 360 degrees output by the one or more magnetic angle sensors after completion of an initialization procedure as one or more starting absolute angles, and the one or more current values ​​measured by the one or more magnetic angle sensors The process includes: calculating one or more current relative angle values ​​based on the relationship between absolute angle values ​​and the one or more starting absolute angles; determining the rotation direction of the one or more rotating components or the one or more driven gears based on at least one set of the one or more current relative angle values ​​and their respective previous relative angle values; determining the number of rotations of the one or more rotating components or the one or more driven gears based on the position changes of at least one set of the one or more current relative angle values ​​and their respective previous relative angle values ​​for a plurality of predefined quadrants; and calculating and determining the actual rotation angle, direction, and number of rotations of the main gear meshing with the one or more rotating components or the one or more driven gears based on at least one of the one or more current relative angle values, the rotation direction of the one or more rotating components or the one or more driven gears, and the number of rotations of the one or more rotating components or the one or more driven gears.

[0007] These and other objects of the present invention will become undoubtedly apparent to those skilled in the art after reading the following detailed description of preferred embodiments shown in various figures and drawings. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a steering angle sensing system according to one embodiment of the present invention.

[0009] [Figure 2] This is a schematic diagram of a steering angle sensing process according to one embodiment of the present invention.

[0010] [Figure 3] This is a schematic diagram of a functional unit set according to one embodiment of the present invention.

[0011] [Figure 4] This is a schematic diagram of a gear system according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] Certain terms are used throughout the specification and claims to refer to specific elements. A person skilled in the art will understand that hardware manufacturers may use different terms to specify the same element. The specification and claims distinguish elements based on their functional differences, not differences in nomenclature. The terms “comprising” and “including” as used herein and in the claims are non-exclusive and should be interpreted as “including, but not limited to.” The term “substantially” refers to the tolerance within which a person skilled in the art can substantially address the technical problem and achieve the intended technical effect. Furthermore, the term “combined” includes any direct or indirect, wired or wireless means of connection.

[0013] To reduce the development or manufacturing costs of steering angle sensors, magnetic angle sensors based on the tunnel magnetoresistance (TMR) effect may be employed. Such sensors output an absolute angle in the range of 0° to 360°, increasing or decreasing the angle based on the direction of rotation. When the angle completes one rotation (left or right), the absolute angle returns to 0° and continues to cycle, increasing or decreasing according to the direction of rotation. However, since TMR magnetic angle sensors only sense and output an absolute angle, challenges arise in zero-angle positioning during assembly and production, as they cannot determine the direction of rotation or the number of turns of the gear. To address this, the present invention proposes a steering system angle sensing method that effectively solves the requirement that the orientation of the single-sided SN bipolar magnet is in a 0° magnetic field for zero-angle positioning during assembly and manufacturing. At the same time, this method converts the absolute angle to a relative angle, determines the direction of rotation and the number of turns, and calculates the final steering angle of the steering system.

[0014] Referring to Figure 1, this figure shows a schematic diagram of a steering angle sensing system 10 according to an embodiment of the present invention. The steering angle sensing system 10 is configured to sense the rotation of a rotating component 12, which may be a gear or any rotatable element on which a magnet MG is placed. The steering angle sensing system 10 comprises a magnetic angle sensor 14 and a determination module 16. The magnetic angle sensor 14 is preferably based on the tunnel magnetoresistance effect and is used to sense the magnetic field angle generated by the magnet MG and output an absolute angle value. The determination module 16 includes a processing unit 160 and a storage unit 162, which use the magnetic angle sensor 14 to sense the rotation of the rotating component 12 (including its rotation angle, number of turns, and direction of rotation). Specifically, the storage unit 162 stores program code 164 that instructs the processing unit 160 to execute a steering angle sensing process 20. The steering angle sensing process 20 converts the absolute angle value sensed by the magnetic angle sensor 14 into a relative angle value, and determines parameters such as the rotation direction and rotation angle of the rotating component 12 based on the absolute angle value and the relative angle value.

[0015] Referring to Figure 2, this diagram shows a schematic view of a steering angle sensing process 20. The steering angle sensing process 20 includes the following steps:

[0016] Step 200: Start.

[0017] Step 202: Record the first set of absolute angle values between 0 degrees and 360 degrees output by the magnetic angle sensor 14 after completion of the initialization procedure as the starting absolute angle.

[0018] Step 204: Calculate an initial relative angle value using a relative angle conversion formula based on the starting absolute angle obtained in step 202.

[0019] Step 206: Determine and acquire the rotation direction of the rotating component 12 based on the current relative angle value converted from the absolute angle value obtained during the rotation of the rotating component 12 and the starting relative angle value obtained in step 204.

[0020] Step 208: Determine and acquire the number of turns of the rotating component 12 based on the rotation direction obtained in step 206 and the position change of the current relative angle value with respect to a plurality of preset quadrants.

[0021] Step 210: Calculate the actual rotation angle of the main gear based on the relative angle value of the rotating component 12 obtained in step 204 and the ratio between the rotating component 12 and the main gear meshed therewith.

[0022] Step 212: End.

[0023] According to the steering angle sensing process 20, the determination module 16 records a first set of absolute angle values ​​between 0 and 360 degrees output by the magnetic angle sensor 14 after the completion of the initialization procedure as the starting absolute angle (step 202), and the starting absolute angle serves as the baseline reference angle. Next, in step 204, the determination module 16 calculates the current initial relative angle value using the relative angle conversion method based on the initial absolute angle value detected in step 202. The initial relative angle value is a primary angle parameter for calculating the rotation of the rotating component 12. Specifically, in one embodiment, if the current absolute angle value is greater than or equal to the starting absolute angle and less than or equal to 360 degrees, the steering angle sensing process 20 determines that the current relative angle value is equal to the current absolute angle value minus the starting absolute angle value. Conversely, if the current absolute angle value is less than the starting absolute angle value, the steering angle sensing process 20 determines that the current relative angle value is equal to the current absolute angle value plus 360 degrees and minus the starting absolute angle value. For example, if the first set of absolute angle values ​​output by the magnetic angle sensor 14 after initialization is 45°, the decision module 16 sets the starting absolute angle to 45° for each steering angle sensing process 20. If the next four absolute angle values ​​detected by the magnetic angle sensor 14 are 45°, 46°, 47°, and 48°, in step 204, the decision module 16 determines the corresponding relative angle values ​​to be 0°, 1°, 2°, and 3°. Conversely, if the four absolute angle values ​​are 45°, 44°, 43°, and 42°, the decision module 16 determines the corresponding relative angle values ​​to be 0°, 359°, 358°, and 357°.

[0024] Next, in step 206, the decision module 16 determines the rotation direction of the rotating component 12 based on the relative angle value calculated this time and the previous relative angle value. For example, in one embodiment, if the current relative angle value is equal to the previous relative angle value, the decision module 16 may determine that the rotating component 12 is stationary at system startup, or that it has completed one full rotation from any direction and returned to its initial absolute angle. According to the definition of generalized trigonometric functions, counterclockwise (leftward) rotation corresponds to an increase in angle, and clockwise (rightward) rotation corresponds to a decrease in angle. If the current relative angle value exceeds the previous relative angle value, the decision module 16 determines that the rotating component 12 is rotating counterclockwise (leftward). Conversely, if the current relative angle value is less than the previous relative angle value, the decision module 16 determines that the rotating component 12 is rotating clockwise (rightward).

[0025] In another embodiment, the decision module 16 may apply a different decision procedure based on the previous rotation direction state. Based on the four-quadrant division of the generalized trigonometric function, the quadrants are defined as follows: first quadrant (angle values ​​0 to 90 degrees), second quadrant (angle values ​​90 to 180 degrees), third quadrant (angle values ​​180 to 270 degrees), and fourth quadrant (angle values ​​270 to 360 degrees). For example, if the previous rotation direction state is stationary, the decision module 16 first compares the current absolute angle value with the starting absolute angle value. If these angle values ​​are equal, the decision module 16 determines that the rotation component 12 remains stationary. However, if the current absolute angle value exceeds the starting absolute angle value and the calculated relative angle value is between 0 and 90 degrees, the decision module 16 determines that the rotation component 12 is rotating toward the first quadrant (e.g., left). Conversely, if the current absolute angle value is smaller than the starting absolute angle value and the calculated relative angle value is between 270 and 359 degrees, the decision module 16 determines that the rotation component 12 is rotating toward the fourth quadrant (e.g., to the right).

[0026] Conversely, if the previous rotation direction state was not stationary, the decision module 16 employs a different decision logic. If the current absolute angle value is equal to the starting absolute angle value, the decision module 16 determines that the rotation component 12 has returned to its starting point, i.e., its initial absolute angle. Otherwise, the decision module 16 determines the current rotation direction based on the previous rotation direction. Furthermore, if the rotation component 12 continues to rotate, the decision module 16 compares the current relative angle value with the previous relative angle value to determine whether the rotation direction has changed. Specifically, if the previous rotation direction state was a left turn and the current relative angle value is equal to the previous relative angle value, it indicates that the rotation angle of the rotation component 12 has returned to its starting position at the start (i.e., a relative angle of 0), which suggests that the rotation component 12 may have completed one left turn or reversed during the left turn. The decision module 16 then records the current rotation direction state as a criterion for the next decision. Similarly, if the previous rotation direction state was a right turn and the current relative angle value is equal to the previous relative angle value, the decision module 16 determines that the rotation component 12 may have completed one right turn or reversed during a right turn, and records the current rotation direction state for the next decision.

[0027] This approach takes into account previous rotational states and applies different criteria based on various conditions, making it possible to more accurately reflect the actual motion state of the rotational component 12, especially during the transition between a stationary state and a moving state, thereby providing highly accurate motion state information.

[0028] Next, in step 208, the determination module 16 determines the number of rotations of the rotating component 12 based on the positional changes of the current relative angle values ​​and previous relative angle values ​​for a set of pre-set quadrants. In one embodiment, the pre-set quadrants are defined based on the transformed relative angle values ​​and include the first quadrant (relative angle values ​​from 0 to 90 degrees), the second quadrant (relative angle values ​​from 90 to 180 degrees), the third quadrant (relative angle values ​​from 180 to 270 degrees), and the fourth quadrant (relative angle values ​​from 270 to 360 degrees). Thus, the determination module 16 tracks the rotation of the rotating component 12 using two quadrant definition systems: an absolute quadrant based on the absolute angle values ​​directly output by the TMR magnetic angle sensor 14, and a relative quadrant based on the transformed relative angle values. Both systems follow a 4-part division of generalized trigonometric functions, with the center of the rotating component 12 as the origin, extending left, right, up, and down to form four regions. In a preferred embodiment, the determination module 16 continuously monitors the changes in relative angle values ​​across these pre-set quadrants and accurately calculates the number of rotations of the rotating component 12. This method ensures highly accurate tracking of rotation, adapts to various installation conditions, and provides reliable angle sensing results. Furthermore, in another embodiment, the number of rotations includes left and right rotations, and when the number of left rotations is equal to the number of right rotations, the determination module 16 resets both counts to zero.

[0029] In short, compared to other sensing methods, embodiments of the present invention use a phase limit approach to determine the number of rotations and effectively address misjudgments caused by the reversing rotation of the rotating component 12 during rotation. Furthermore, the determination module 16 tracks the motion path of the rotating component 12 based on the quadrant definitions of generalized trigonometric functions. As the rotating component 12 performs a left or right rotation, its angular position sequentially traverses four phase limits. The determination module 16 uses this data as motion path parameters to continuously track and record the current quadrant position of the rotating component 12.

[0030] Specifically, the decision module 16 first determines and selects whether to perform a left turn or a right turn based on the current rotation direction and a comparison of the current relative / absolute angle with the previous relative / absolute angle. The decision module 16 uses the absolute and relative angle values ​​to determine the quadrant position of the current angle and updates the quadrant state in real time. At the same time, the decision module 16 records the quadrants traversed in the movement path parameters. In particular, when processing a right turn, the decision module 16 subtracts 360 degrees from the relative angle value obtained and converted from the magnetic angle sensor 14, keeping it within the range of -1 to -359 degrees. This approach is consistent with the positive and negative angle definitions in generalized trigonometric functions, where counterclockwise (left turn) is positive and clockwise (right turn) is negative.

[0031] When the decision module 16 detects that the motion path parameters match those of a complete rotation (indicating that the rotational component 12 has completely traversed all four quadrants), the system decides whether to increment the number of left turns or right turns based on the direction of rotation. In particular, if both the number of left turns and the number of right turns are not zero but equal, this means that the rotational component 12 has returned to its relative zero-degree angular position at the initial start, indicating that the rotational component 12 is perfectly centered without any angular offset.

[0032] This phase limit-based method for calculating the number of turns not only accurately tracks the rotation of the rotating component 12 but also correctly handles reverse motion, thus providing a reliable and highly accurate steering angle monitoring solution.

[0033] Finally, in step 210, the determination module 16 calculates the actual rotation angle of the main gear and determines its actual rotation direction and number of turns based on the relative angle values, rotation direction, and number of turns of the rotating component 12, and the gear ratio between the rotating component 12 and the main gear meshed with it. This comprehensive rotational information derived from the rotating component 12 makes it possible to provide a more complete state of motion of the steering system, including its highly accurate rotation angle, direction, and completed number of turns.

[0034] It should be noted that the steering angle sensing process 20 in this embodiment includes a mechanism to correct and restore the angle if the initial relative angle calculated in step 204 is 0°, even though the rotating component 12 is in an off-center state from the user's viewpoint at system startup (the initial relative angle is not 0°). Specifically, at system startup, the determination module 16 retrieves the initial absolute angle and initial relative angle (stored in a non-volatile memory device and representing a centered state with an angle of 0°), and compares them with a first set of initial absolute angle values ​​output by the magnetic angle sensor 14 after initialization and the converted initial relative angle. The determination module 16 then calculates an angle offset value for compensation to correct the rotation angle of the rotating component 12, thereby improving sensing accuracy.

[0035] The steering angle sensing process 20 exemplifies the main concepts of the present invention and should be noted by those skilled in the art that various modifications can be made without limiting it. For example, when the steering angle sensing process 20 is implemented in software, each step or its derivative may be implemented through different functional units, which can be considered as program sets, threads, or functions, respectively. As will be well understood by those skilled in the art, auxiliary means may be added as appropriate to implement the steering angle sensing process 20. Referring to Figure 3, this figure shows a schematic diagram of a functional unit set 30 according to an embodiment of the present invention. The functional unit set 30 corresponds to a thread of program code 164 for implementing the steering angle sensing process 20. The functional unit set 30 comprises an startup absolute angle initialization unit 300, an absolute angle-to-relative angle conversion unit 302, a storage unit 304, a correction unit 306, a rotation direction determination unit 308, a turn count determination unit 310, and an actual rotation angle, direction, and turn count calculation determination unit 312. The storage unit 304 stores the data necessary to execute the steering angle sensing process 20. Also, θ° abs θ° is the absolute angle value measured by the magnetic angle sensor 14. star_abs θ° is the absolute starting angle. relis the relative angle value, GRD is the rotation direction, and ROT is the number of rotations. Specifically, the startup absolute angle initialization unit 300 executes step 202 to output the absolute angle value θ° from the magnetic angle sensor 14 after initialization abs The first set of absolute angle values of is recorded as the startup absolute angle θ° star_abs . The absolute angle-relative angle conversion unit 302 executes step 204 to obtain the current absolute angle value θ° of the magnetic angle sensor 14 abs and the startup absolute angle value θ° star_abs The relative angle value θ° is calculated based on the relationship between rel , and the relative angle value θ° is stored in the storage unit 304 rel . The rotation direction determination unit 308 executes step 206 to obtain the current relative angle value θ° rel and the previous relative angle value θ° stored in the storage unit 304 rel The rotation direction GRD of the rotating component 12 is determined based on the angle comparison between the two, and the determined rotation direction GRD is stored in the storage unit 304. The rotation number determination unit 310 executes step 208 to obtain the current relative angle value θ° rel and the previous relative angle value θ° stored in the storage unit 304 rel The number of rotations ROT of the rotating component 12 is determined based on the position change with respect to a plurality of preset quadrants. The actual rotation angle, direction, and rotation number calculation and determination unit 312 executes step 210 to obtain the relative angle value θ° rel , the rotation direction GRD, and the number of rotations ROT, to determine and calculate the actual rotation state (angle, direction, number of rotations) of the main gear meshed with the rotating component 12. Further, the correction unit 306 outputs the startup absolute angle value θ° from the magnetic angle sensor 14 after the initialization correction procedure is completed star_abs and the converted relative angle value θ° when the main gear meshed with the rotating component 12 is located at the center and is at 0° from the user's viewpoint relThe values ​​are stored in the memory unit 304. The correction unit 306 reads the correction angle value and the absolute angle sensed by the magnetic angle sensor 14 from the memory unit 304 when the system is started again, and provides them to the startup absolute angle initialization unit 300 to determine and correct the rotation angle when the rotating component 12 is not located at the center from the user's viewpoint (initial relative angle 0°), thereby improving the sensing accuracy.

[0036] The functional unit set 30 represents a feasible architecture for performing the steering angle sensing process 20, and its detailed operation or derivatives can be found in the preceding description of the steering angle sensing process 20, which will not be repeated here. Furthermore, in the functional unit set 30, the connections between units are not limited to signal connections, as is well known to those skilled in the art, but may represent operations such as data transfer or function calls.

[0037] Regarding hardware implementation, the processing unit 160 of the decision module 16 may be a microprocessor, a digital signal processor (DSP), or a microcontroller, and the storage unit 162 may comprise read-only memory (ROM), random access memory (RAM), flash memory, or other memory devices. The program code 164 is stored in the storage unit 162, and the processing unit 160 reads and executes the program code 164 at system startup to realize the functionality of the steering angle sensing process 20. In another embodiment, computationally intensive or time-critical functions (e.g., angle calculation, direction determination) may be implemented via hardware circuitry, while more complex logical decisions are handled through software. This hybrid approach balances performance and flexibility, ensuring real-time operation and scalability. Regardless of the implementation, the decision module 16 must accurately acquire signals or data from the magnetic angle sensor 14, for example, through a standard communication protocol such as a serial communication interface (SCI), serial peripheral interface (SPI), or inter-integrated circuit (I2C).

[0038] Furthermore, as mentioned above, the rotating component 12 may be any rotatable element. The steering angle sensing system 10 of the present invention senses the magnetic field angle generated by the magnet MG via the magnetic angle sensor 14, converts the obtained absolute angle value into a relative angle value, and determines the rotation direction and number of rotations of the rotating component 12. Thus, the present invention not only solves the problem of misjudgment in conventional sensing methods during reverse motion, but also provides enhanced rotation state monitoring capabilities. In particular, the steering angle sensing system 10 can not only sense the steering angle of a single rotating component 12, but can also be adjusted as appropriate and applied to a gear system having multiple driven gears to calculate the steering angle of the main gear. In such a scenario, the system must take into account the gear ratio in order to accurately calculate the actual rotation of the main gear.

[0039] Referring to Figure 4, for example, this figure shows a schematic diagram of a gear system 40 according to an embodiment of the present invention. The gear system 40 forms part of a steering system and comprises a main gear 42 and driven gears 44 and 46. The center of the main gear 42 is connected to or coupled to a steering shaft, which is further connected to or coupled to a steering wheel or other steering device, so that the main gear 42 can rotate together with the steering wheel or device. The driven gears 44 and 46 mesh with the main gear 42, which has fewer teeth than the main gear 42. Therefore, when the steering wheel rotates, the main gear 42 rotates accordingly, and the driven gears 44 and 46 also rotate in conjunction with it.

[0040] In this embodiment, the driven gears 44 and 46 are equipped with magnets and configured together with their respective steering angle sensing systems (e.g., steering angle sensing system 10 in Figure 1). The calculation module then integrates the steering angle determination results of the driven gears 44 and 46. In another embodiment, the driven gears 44 and 46 may share or partially share the determination module of the steering angle sensing system (e.g., determination module 16 in Figure 1). Regardless of the embodiment, the steering angle sensing system applicable to the gear system 40 detects the rotation of the driven gears 44 and 46 and performs a steering angle sensing process 20 to calculate their respective relative angle values, rotation direction, and turns. Subsequently, the steering angle sensing system converts the steering angles of the driven gears 44 and 46 to the steering angles of the main gear 42 based on the gear ratio between the driven gears 44 and 46 and the main gear 42. For example, if the main gear 42 has 60 teeth and the driven gears 44 and 46 each have 20 teeth, the gear ratio is 3:1, meaning that three turns of the driven gears 44 and 46 are equivalent to one turn of the main gear 42. In this case, the steering angle sensing system determines the actual rotation angle of the main gear 42 by dividing the relative angle values ​​of the driven gears 44 and 46 by 3. Similarly, the actual number of turns of the main gear 42 is determined by dividing the number of turns of the driven gears 44 and 46 by 3.

[0041] Furthermore, in the gear system 40, when two driven gears 44 and 46 are used, in one embodiment, their steering angle results may be summed and averaged to reduce errors. In another embodiment, one of the driven gears 44 and 46 may function as a redundant design, and the steering angle sensing system determines the steering angle of the main gear 42 based on the result of only one driven gear, while the other is used for verification or fault backup. Furthermore, the driven gears 44 and 46 in the gear system 40 have the same number of teeth, but are not limited to this. The present invention may use multiple driven gears with different numbers of teeth to determine the steering angle of the main gear, provided that the conversion is performed according to the gear ratio, as can be derived by those skilled in the art from the foregoing. Furthermore, in addition to using two driven gears 44 and 46, a single driven gear or more than three driven gears may be used, and such variations are readily deriveable by those skilled in the art based on the above description and are therefore not described in detail here.

[0042] Simply put, the steering angle sensing system of the present invention accurately calculates the steering angle of the main gear by comparing data from one or more driven gears. This redundant design improves the reliability of the system and ensures continued operation even if a sensor on a driven gear fails. It also improves configuration flexibility, as the sensor installation is no longer limited to the main gear, which is particularly advantageous when space is limited or when installing a sensor on the main gear is not practical.

[0043] For example, the steering angle sensing system 10 of the present invention may be applied to a vehicle's steering wheel angle sensing system. In this case, the system must accurately sense the steering angle of the steering wheel, taking into account the mechanical linkage mechanism between the steering wheel and the steering mechanism, and provide accurate steering information to the vehicle's electronic control system. Using the present invention, a magnetic angle sensor is installed in the gear set of the steering mechanism. Given that the steering wheel is typically capable of multiple turns (e.g., three to four turns from left to right), the multi-turn counting capability of the steering angle sensing process 20 is important. The system accurately reflects the position of the steering wheel by continuously tracking and accumulating the steering angle, number of turns, and direction of rotation of the steering wheel. Furthermore, since the steering wheel system interacts closely with other vehicle electronic control units (e.g., the electronic stability control (ESC) and the anti-lock braking system (ABS), the steering angle sensing process 20 must provide accurate steering angle data in real time. In practice, the system converts the sensed steering angle into a standard format and transmits it to the relevant control unit via the vehicle's communication network (e.g., the CAN bus).

[0044] In particular, when the vehicle starts up, the initial position of the steering wheel may be off-center. In this case, the angle correction function of the steering angle sensing process 20 automatically sets the current position as the relative zero-degree reference point at startup and compensates by tracking the relative displacement during rotation. This ensures that accurate steering angle information is obtained even if the steering wheel is off-center.

[0045] Applying this invention to steering wheel angle sensing provides accurate steering angle data, supporting advanced active safety systems and driver assistance functions in modern vehicles and laying a crucial foundation for safe driving.

[0046] As described above, the steering angle sensing system and method of the present invention senses the magnetic field angle generated by a magnet via a magnetic angle sensor, converts the absolute angle value to a relative angle value to determine the direction of rotation, and calculates the number of rotations of the rotating component. Therefore, the present invention solves the erroneous judgments in conventional sensing methods during reverse motion and improves the accuracy of rotation state monitoring. Furthermore, the system divides the rotation into four quadrants and employs a relative quadrant determination mechanism to calculate the tracking angle change within them with high accuracy, making it ideal for multi-turn counting applications such as steering wheel angle sensing. The angle correction function further compensates for offsets due to installation variations, significantly improving practicality and reliability.

[0047] In practical applications, the steering angle sensing system and process offer excellent adaptability and scalability, accurately sensing rotation in systems involving one or more driven gears, such as vehicle steering angle monitoring. This broad applicability makes the invention highly suitable for modern industrial automation and vehicle electronic control systems.

[0048] In summary, through magnetic sensing technology and calculation methods, the present invention realizes an accurate, reliable, and practical rotation angle sensing system applicable to fields such as industrial automation and vehicle control.

[0049] Those skilled in the art will readily understand that numerous modifications and changes can be made to the apparatus and method while retaining the teachings of the present invention. Therefore, the foregoing disclosure should be interpreted as being limited only by the boundaries of the appended claims.

Claims

1. A steering system angle sensing method for sensing the rotation of one or more rotating components in a steering system, wherein each of the one or more rotating components is composed of a magnet, and the steering system is The main gear connected to the steering shaft, One or more driven gears that mesh with the main gear, One or more magnets are arranged on each of the one or more driven gears, One or more magnetic angle sensors, each configured to sense the magnetic field angle generated by one or more magnets and output one or more absolute angle values, Processing unit and A storage unit coupled to the processing unit, which stores program code that instructs the processing unit to execute the steering system angle sensing method, and which enables sensing the rotation of one or more rotating components or driven gears using one or more magnetic angle sensors, The steering system angle sensing method is provided, The steps include recording one or more first sets of absolute angle values ​​between 0 degrees and 360 degrees output by one or more magnetic angle sensors after the completion of the initialization procedure as one or more starting absolute angles, A step of calculating one or more current relative angle values ​​based on the relationship between one or more current absolute angle values ​​measured by one or more magnetic angle sensors and one or more starting absolute angles, A step of determining the rotation direction of one or more rotating components or one or more driven gears based on at least one set of one or more current relative angle values ​​and their respective previous relative angle values, A step of determining the number of rotations of one or more rotating components or one or more driven gears based on the positional changes of one or more current relative angle values ​​and at least one set of previous relative angle values ​​for a plurality of pre-set quadrants, A step of calculating and determining the actual rotation angle, direction, and number of rotations of the main gear meshing with the one or more rotating components or the one or more driven gears, based on at least one of the one or more current relative angle values, the rotation direction of the one or more rotating components or the one or more driven gears, An angle sensing method for a steering system, including the above.

2. The step of calculating the one or more current relative angle values ​​based on the relationship between the one or more current absolute angle values ​​measured by the one or more magnetic angle sensors and the one or more starting absolute angles is: If the one or more current absolute angle values ​​are greater than or equal to the one or more starting absolute angles and less than or equal to 360 degrees, the step of determining that the one or more current relative angle values ​​are equal to the value obtained by subtracting the one or more starting absolute angles from the one or more current absolute angle values, If the one or more current absolute angle values ​​are smaller than the one or more starting absolute angles, the step of determining that the one or more current relative angle values ​​are equal to the value obtained by adding 360 degrees to the one or more current absolute angle values ​​and subtracting the one or more starting absolute angles, The steering system angle sensing method according to claim 1, including the method described in claim 1.

3. The step of determining the rotational direction of one or more rotating components or one or more driven gears based on at least one set of one or more current relative angle values ​​and their respective previous relative angle values ​​includes the step of determining the current rotational direction state of each of the one or more rotating components or one or more driven gears based on the previous rotational direction state of the one or more rotating components or one or more driven gears and the relationship between their respective current absolute angle value and starting absolute angle, If the one or more current relative angle values ​​are equal to their respective previous relative angle values, the step of determining that the one or more rotating components or the one or more driven gears are in a stationary state, If one or more of the current relative angle values ​​exceed their respective previous relative angle values, the step of determining, according to the definition of generalized trigonometric functions, that one or more of the rotating components or one or more of the driven gears are rotating toward or counterclockwise to the first quadrant, If one or more of the current relative angle values ​​are smaller than their respective previous relative angle values, the step of determining, according to the definition of generalized trigonometric functions, that one or more of the rotating components or one or more of the driven gears are rotating toward the fourth quadrant or clockwise, The steering system angle sensing method according to claim 1, including the method described in claim 1.

4. The number of rotations includes left rotations and right rotations, and the step of determining the number of rotations of one or more rotating components or one or more driven gears based on the positional changes of one or more current relative angle values ​​and each of their previous relative angle values ​​with respect to a plurality of pre-set quadrants is: A step of recording a sequence of at least one set of the one or more current relative angle values ​​and their respective previous relative angle values ​​for the plurality of pre-set quadrants, When at least one set of one or more current relative angle values ​​and their respective previous relative angle values ​​completely traverses the plurality of pre-set quadrants in sequence, the step of accumulating the number of turns, When the number of left turns is equal to the number of right turns, the steps include resetting the number of turns and the number of right turns, The steering system angle sensing method according to claim 1, including the method described in claim 1.

5. The steering system angle sensing method according to claim 1, wherein the plurality of pre-set quadrants include a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, the first quadrant being in the range of 0 to 90 degrees with respect to one or more current angle values, the second quadrant being in the range of 90 to 180 degrees with respect to one or more current angle values, the third quadrant being in the range of 180 to 270 degrees with respect to one or more current angle values, and the fourth quadrant being in the range of 270 to 360 degrees with respect to one or more current angle values.

6. After the completion of the initialization procedure, the steps include recording one or more first sets of absolute angle values ​​between 0 degrees and 360 degrees output by one or more magnetic angle sensors, and their respective converted initial relative angle values, comparing them with one or more relative angle values ​​converted from the one or more absolute angle values ​​currently sensed by the one or more magnetic angle sensors, and determining one or more angle offset values, After the completion of the initialization procedure, the following steps are taken: reading the one or more initial absolute angle values ​​stored in the storage device and the respective initial relative angle values ​​converted from one or more first sets of absolute angle values ​​between 0 degrees and 360 degrees output by the one or more magnetic angle sensors, and performing a compensation calculation for the angle offset value to correct the rotation angle of the one or more rotating components or the one or more driven gears; The steering system angle sensing method according to claim 1, further comprising:

7. The steering system angle sensing method according to claim 1, wherein the one or more rotating components are one or more driven gears.

8. The step of determining the rotation of the main gear based on the one or more relative angle values, the rotation direction of the one or more driven gears, and the number of rotations of the one or more driven gears is: The steps include determining the rotational ratio relationship of one or more driven gears to the main gear based on the gear ratio of the main gear to the one or more driven gears, A step of converting the one or more relative angle values, the rotation direction of the one or more driven gears, and the number of rotations of the one or more driven gears into the rotation angle, rotation direction, and number of rotations of the main gear based on the rotation ratio relationship, The steering system angle sensing method according to claim 1, including the method described in claim 1.

9. The steering system angle sensing method according to claim 8, wherein the steering shaft is connected to the steering wheel.

10. The steering system angle sensing method according to claim 9, further comprising the step of converting the rotation of the main gear into a steering angle of the steering wheel.

11. The steering system angle sensing method according to claim 1, further comprising at least one redundant driven gear, at least one redundant magnet, and at least one redundant magnetic angle sensor configured to replace the faulty component when one or more of the one or more driven gears, one or more magnets, and one or more magnetic angle sensors fail.

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