Failure detection device for a steering angle sensor and control method thereof

Abstract

A fault detection device for a steering angle sensor according to one embodiment includes: a steering angle sensor, comprising a main gear that rotates together with a steering wheel, a first auxiliary gear and a second auxiliary gear that mesh with the main gear while having a predetermined gear ratio, a first Hall IC chip for detecting the angle of the first auxiliary gear and a second Hall IC chip for detecting the angle of the second auxiliary gear; and a control unit that determines a fault in the steering angle sensor based on a first angle difference between a current time point and a past time point of the angle of the first auxiliary gear detected by the first Hall IC chip and a second angle difference between a current time point and a past time point of the angle of the second auxiliary gear detected by the second Hall IC chip.

Description

Technical Field

[0001] The disclosed invention relates to a fault detection device and control method for a steering angle sensor that detects the steering angle of a steering wheel installed in a vehicle. Background Technology

[0002] Typically, electric steering systems used in vehicles may include a steering angle sensor, which is mounted on a steering shaft that is linked to the steering wheel operated by the driver to transmit operating forces, and detects the rotation angle of the steering wheel, i.e., the steering angle.

[0003] The steering angle sensor may include: a main gear mounted on the steering shaft; a first auxiliary gear and a second auxiliary gear meshing with the main gear at a predetermined gear ratio; magnets attached to the first auxiliary gear and the second auxiliary gear respectively; and a first Hall IC chip and a second Hall IC chip for detecting changes in the magnetic field emitted by each magnet.

[0004] The power from the first and second Hall IC chips of the steering angle sensor can be output to the electronic control unit (ECU) of the electric steering system. The first Hall IC chip can output the rotation angle of the first gear, and the second Hall IC chip can output the rotation angle of the second gear.

[0005] The rotation angle of the steering shaft can be determined by the rotation angle of the first gear and the rotation angle of the second gear.

[0006] There are several methods for calculating the steering angle by combining the angle information of two auxiliary gears and detecting fault states caused by current algorithm errors or noise.

[0007] The meshing of the primary gear and the two secondary gears can significantly affect the accuracy of the steering angle. Currently, there is no technology to detect malfunctions caused by variations in the amount of force applied to each gear during steering wheel operation. Besides malfunctions caused by algorithmic errors and noise, for example, when the gear teeth are worn or deformed, the meshing of the primary gear and each secondary gear may become misaligned. Therefore, incorrect angle information may be output each time that interval is traversed, potentially leading to an incorrectly calculated steering angle. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] One aspect of the disclosed invention aims to provide a fault detection device and control method for a steering angle sensor that can more effectively detect faults caused by gear deformation or damage to the steering angle sensor.

[0010] (II) Technical Solution

[0011] One aspect of the disclosed invention provides a fault detection device for a steering angle sensor, comprising: a steering angle sensor including a main gear rotating together with a steering wheel, a first auxiliary gear and a second auxiliary gear meshing with the main gear at a predetermined gear ratio, a first Hall IC (Integrated Circuit) chip for detecting the angle of the first auxiliary gear, and a second Hall IC chip for detecting the angle of the second auxiliary gear; and a control unit that determines a fault in the steering angle sensor based on a first angle difference between a current time point and a past time point of the angle of the first auxiliary gear detected by the first Hall IC chip and a second angle difference between a current time point and a past time point of the angle of the second auxiliary gear detected by the second Hall IC chip.

[0012] The control unit can count the number of times the first angle difference is greater than a predetermined angle, and when the counted number is greater than the predetermined number, it can be determined that the steering angle sensor is malfunctioning due to damage to the teeth of the first auxiliary gear.

[0013] The control unit can count the number of times the second angle difference is greater than a predetermined angle, and when the counted number is greater than the predetermined number, it can be determined that the steering angle sensor is malfunctioning due to damage to the teeth of the second auxiliary gear.

[0014] The control unit can count the number of times the first angle difference is greater than a predetermined angle, count the number of times the second angle difference is greater than a predetermined angle, and sum the counts of each. When the sum of the counts is greater than a predetermined number, it can be determined that the fault is caused by damage to the gear of the steering angle sensor.

[0015] The control unit can determine the fault of the steering angle sensor based on the first angle difference, the second angle difference, and the first angle difference minus the second angle difference, which is the angle difference between the first angle difference and the second angle difference.

[0016] The control unit can count the number of times the first angle difference is greater than a predetermined angle, count the number of times the second angle difference is greater than a predetermined angle, and count the number of times the first angle difference minus the second angle difference is greater than a predetermined angle, and sum the counts of each. When the total count is greater than a predetermined count, it can be determined that the fault is caused by damage to the gear of the steering angle sensor.

[0017] The control unit can determine the fault of the steering angle sensor based on the first angle difference - second angle difference, which is the angle difference between the first angle difference and the second angle difference.

[0018] The control unit can count the number of times the first angle difference minus the second angle difference is greater than a predetermined angle, and sum the counted number of times. When the summed number of times is greater than the predetermined number of times, it can be determined that the fault is caused by damage to the gear of the steering angle sensor.

[0019] Another aspect of the disclosed invention provides a method for detecting a fault in a steering angle sensor, wherein the steering angle sensor includes a first auxiliary gear and a second auxiliary gear, the first auxiliary gear and the second auxiliary gear meshing with the main gear while having a predetermined gear ratio, the main gear rotating together with a steering wheel, and the method for detecting a fault in the steering angle sensor includes the following steps: detecting the angle of the first auxiliary gear; detecting the angle of the second auxiliary gear; calculating a first angle difference between the current time point and a past time point of the angle of the first auxiliary gear; calculating a second angle difference between the current time point and a past time point of the angle of the second auxiliary gear; and determining a fault in the steering angle sensor based on the first angle difference and the second angle difference.

[0020] In the step of determining the fault of the steering angle sensor, the number of times the first angle difference is greater than a predetermined angle is counted, and when the counted number is greater than the predetermined number, it can be determined that the fault of the steering angle sensor is caused by damage to the teeth of the first auxiliary gear.

[0021] In the step of determining the fault of the steering angle sensor, the number of times the second angle difference is greater than a predetermined angle is counted, and when the counted number is greater than the predetermined number, it can be determined that the fault of the steering angle sensor is caused by damage to the teeth of the second auxiliary gear.

[0022] In the step of determining the fault of the steering angle sensor, the number of times the first angle difference is greater than a predetermined angle is counted, the number of times the second angle difference is greater than a predetermined angle is counted, and the counts of each are totaled. When the total count is greater than the predetermined count, it can be determined that the fault is caused by damage to the gear of the steering angle sensor.

[0023] The first angle difference minus the second angle difference can be further calculated as the angle difference between the first angle difference and the second angle difference, and the fault of the steering angle sensor can be determined based on the first angle difference, the second angle difference, and the first angle difference minus the second angle difference.

[0024] In the step of determining the fault of the steering angle sensor, the number of times the first angle difference is greater than a predetermined angle is counted, the number of times the second angle difference is greater than a predetermined angle is counted, and the number of times the first angle difference minus the second angle difference is greater than a predetermined angle is counted. The counts of each are then totaled. When the total number of counts is greater than a predetermined number, it can be determined that the fault is caused by damage to the gear of the steering angle sensor.

[0025] In the step of determining the fault of the steering angle sensor, the fault of the steering angle sensor can be determined based on the first angle difference - the second angle difference, which is the angle difference between the first angle difference and the second angle difference.

[0026] In the step of determining the fault of the steering angle sensor, the number of times the first angle difference minus the second angle difference is greater than a predetermined angle is counted, and the total number of counts is added together. When the total number of counts is greater than the predetermined number, it can be determined that the fault is caused by damage to the gear of the steering angle sensor.

[0027] (III) Beneficial Effects

[0028] According to one aspect of the disclosed invention, it is possible to more effectively detect faults caused by gear deformation or damage to the steering angle sensor. Attached Figure Description

[0029] Figure 1 A steering angle sensor is shown as applied to a steering angle sensor fault detection device according to one embodiment.

[0030] Figure 2 The control block of a steering angle sensor fault detection device according to one embodiment is shown.

[0031] Figure 3 The diagram illustrates the meshing between the main gear and two auxiliary gears when the teeth of the main gear are damaged in a steering angle sensor fault detection device according to one embodiment.

[0032] Figure 4 A control method for a steering angle sensor fault detection device according to one embodiment is shown.

[0033] Figure 5 and Figure 6 A control method for a steering angle sensor fault detection device according to another embodiment is shown.

[0034] Figure 7 A control method for a steering angle sensor fault detection device according to yet another embodiment is shown. Detailed Implementation

[0035] Throughout this specification, the same reference numerals refer to the same components. This specification does not describe all elements of the embodiments and omits general content or repetition between embodiments within the art to which the disclosed invention pertains. The terms "part," "module," "component," and "block" as used in this specification can be implemented in software or hardware, and according to embodiments, multiple "parts," "modules," "components," and "blocks" can be implemented by a single component, or a single "part," "module," "component," and "block" can include multiple components.

[0036] Throughout the specification, when describing a part as "connected" to another part, this includes not only direct connections but also indirect connections, including connections via wireless communication networks.

[0037] In addition, when describing a part as "including" a component, unless otherwise stated, it means that other components may be included, rather than excluding other components.

[0038] Throughout the instruction manual, when describing a component as being "on" another component, this includes not only cases where one component is connected to another component, but also cases where there are other components between the two components.

[0039] The terms "first," "second," etc., are used to distinguish one component from another; the components are not limited by these terms. Unless otherwise expressly stated in the context, singular expressions include plural expressions.

[0040] In each step, reference numerals are used for ease of description. The reference numerals do not describe the order of the steps. Unless a specific order is explicitly stated in the context, the order of execution of the steps may differ from the specified order.

[0041] Figure 1 A steering angle sensor is shown as applied to a steering angle sensor fault detection device according to one embodiment. Figure 2 The control block of a steering angle sensor fault detection device according to one embodiment is shown.

[0042] Reference Figure 1 and Figure 2 The steering angle sensor fault detection device may include a steering angle sensor 10, a control unit 20, and a warning unit 30.

[0043] The steering angle sensor 10 may include: a main gear 11 mounted on a steering shaft; a first auxiliary gear 12 and a second auxiliary gear 13 meshing with the main gear 11 at a predetermined gear ratio; a first magnet 14 attached to the first auxiliary gear 12 and a second magnet 15 attached to the second auxiliary gear 13; a first Hall IC chip 16 and a second Hall IC chip 17 for detecting changes in the magnetic field emitted by each magnet 14, 15; a printed circuit board 18 on which the first Hall IC chip 16 and the second Hall IC chip 17 are mounted; and an upper cover 19a and a lower cover 19b covering the above components.

[0044] The main gear 11 can have n teeth.

[0045] The number of teeth on the two auxiliary gears 12 and 13 can be less than the number of teeth on the main gear 11.

[0046] The first gear 12 and the second gear 13 can have different numbers of teeth. For example, the first gear 12 can have m teeth, and the second gear 13 can have m+1 teeth.

[0047] The printed circuit board 18 can be electrically connected to the electronic control unit (ECU) of the electric steering system via a connector that is electrically connected to the wiring pattern.

[0048] The main gear 11 meshes with the two auxiliary gears 12 and 13.

[0049] When the main gear 11 rotates, the two auxiliary gears 12 and 13 can also rotate.

[0050] Since the main gear 11 and the two auxiliary gears 12 and 13 have different numbers of teeth, the rotation angles of the main gear 11 and the two auxiliary gears 12 and 13 can be different when each gear rotates.

[0051] When the main gear 11 rotates once, the two auxiliary gears 12 and 13 can rotate multiple times.

[0052] The first Hall IC chip 16 can generate a voltage signal as a function of the angle of the first auxiliary gear 12 by using the magnetic field released from the first magnet 14.

[0053] The second Hall IC chip 17 can generate a voltage signal as a function of the angle of the second auxiliary gear 13 by using the magnetic field released from the second magnet 15.

[0054] The voltage change can occur repeatedly each time the first auxiliary gear 12 and the second auxiliary gear 13 rotate once.

[0055] The control unit 20 can be named an electronic control unit (ECU).

[0056] The control unit 20 may include a processor 21 and a memory 22.

[0057] The memory 22 can store programs for processing or control by the processor 21, as well as various data related to steering angle calculation and fault diagnosis of the steering angle sensor 10.

[0058] The memory 22 may include not only volatile memories such as Static Random Access Memory (S-RAM) and Dynamic Random Access Memory (DRAM), but also non-volatile memories such as flash memory, read-only memory (ROM), and erasable programmable read-only memory (EPROM).

[0059] The processor 21 can control the overall operation used to determine the fault of the steering angle sensor 10.

[0060] The control unit 20 with the above structure can be electrically connected to the printed circuit board 18 to receive angle information of each gear 12, 13 from the first Hall IC chip 16 and the second Hall IC chip 17.

[0061] When the driver turns the steering wheel, the main gear 11 mounted on the steering shaft rotates in conjunction, and as the main gear 11 rotates, the two auxiliary gears 12 and 13 also rotate together.

[0062] In this state, the control unit 20 can receive the angle signal output by the first Hall IC chip 16 when the first auxiliary gear 12 rotates and the angle signal output by the second Hall IC chip 17 when the second auxiliary gear 13 rotates. It can estimate the angle of the main gear 11 using each received angle signal, thereby calculating the steering angle. When estimating the angle of the main gear 11, the control unit 20 can use the number of teeth n of the main gear 11, the number of teeth m of the first auxiliary gear 12, and the number of teeth m+1 of the second auxiliary gear 13.

[0063] In addition, the control unit 20 can determine the failure of the steering angle sensor 10 caused by damage to each gear 11, 12, 13 based on the first gear angle signal output from the first Hall IC chip 16 and the second gear angle signal output from the second Hall IC chip 17.

[0064] The control unit 20 can warn the driver of a malfunction in the steering angle sensor 10 through the warning unit 30.

[0065] The warning unit 30 may include a speaker display module, which outputs a message to the driver informing him of a malfunction in the steering angle sensor 10 based on the control signal from the control unit 20.

[0066] Figure 3 The diagram illustrates the meshing between the main gear and two auxiliary gears when the teeth of the main gear are damaged in a steering angle sensor fault detection device according to one embodiment.

[0067] Figure 3 This shows the state in which some teeth of the main gear 11 are damaged or missing.

[0068] At this time, when the two secondary gears 12 and 13 mesh with the damaged teeth of the primary gear 11 and rotate, tooth jumping may occur. This can lead to abnormal steering angle movement. Specifically, when the steering wheel is operated in a specific direction, incorrect steering angle sensing information or mechanical failure may cause a steering angle change exceeding the permissible range. This could result in unexpected control of the electric power steering system.

[0069] In addition, if the teeth of the two auxiliary gears 12 and 13 are damaged or missing, the change in steering angle may exceed the allowable range.

[0070] To address this situation, it is necessary to detect faults caused by gear deformation or damage to the steering angle sensor.

[0071] The control unit 20 can calculate the difference between the first gear angle of the first gear 12 at the current time point and the first gear angle at a past time point.

[0072] The control unit 20 can calculate the difference between the second gear angle of the second gear 13 at the current time point and the second gear angle at a past time point.

[0073] The control unit 20 can determine the fault of the steering angle sensor 10 based on the angle difference between the first gear and the second gear.

[0074] When the angle difference of the first gear is greater than a predetermined angle or the angle difference of the second gear is greater than a predetermined angle, the control unit 20 can determine that the steering angle sensor 10 may have malfunctioned.

[0075] When the angle difference of the first gear is greater than a predetermined angle, the control unit 20 can add a fault flag. When the angle difference of the second gear is greater than a predetermined angle, the control unit 20 can add a fault flag. And when the added fault flag is greater than a predetermined value, the control unit 20 can determine that the steering angle sensor 10 has malfunctioned. At this time, the control unit 20 can determine that the malfunction is caused by damage to the gears of the steering angle sensor 10.

[0076] On the other hand, the control unit 20 calculates the angle difference between the first gear angle difference and the second gear angle difference, and when the calculated angle difference is greater than a predetermined angle, the control unit 20 can determine that the steering angle sensor 10 may have malfunctioned.

[0077] The control unit 20 counts the number of times the angle difference of the first gear is greater than a predetermined angle (a predetermined first value), counts the number of times the angle difference of the second gear is greater than a predetermined angle (a predetermined second value), and counts the number of times the angle difference between the first and second gears is greater than a predetermined angle (a predetermined third value). The control unit 20 then sums the counts for each gear. When the total sum exceeds a predetermined number, the control unit 20 determines that the steering angle sensor 10 has malfunctioned due to gear damage. In this case, the predetermined first value, the predetermined second value, and the predetermined third value may be the same or different.

[0078] Figure 4 A control method for a steering angle sensor fault detection device according to one embodiment is shown.

[0079] Reference Figure 4 The control unit 20 can receive the angle signal of the first auxiliary gear 12 from the first Hall IC chip 16 of the steering angle sensor 10, thereby detecting the angle (100) of the first auxiliary gear 12.

[0080] The control unit 20 can receive the angle signal of the second auxiliary gear 13 from the second Hall IC chip 17 of the steering angle sensor 10, thereby detecting the angle (102) of the second auxiliary gear 13.

[0081] The control unit 20 can calculate the first angle difference (104) between the angle of the first gear 12 at the current time point and the angle at a past time point.

[0082] The control unit 20 can calculate the second angle difference (106) between the angle of the second gear 13 at the current time point and the angle at a past time point.

[0083] The control unit 20 can determine whether the first angle difference exceeds the predetermined first angle Thr1 (108).

[0084] If the judgment result of operation mode 108 is that the first angle difference exceeds the predetermined first angle Thr1, the control unit 20 may add a first fault flag (110). The first fault flag may indicate that the first auxiliary gear 12 may have damaged or missing teeth.

[0085] On the other hand, when the judgment result of operation mode 108 is that the first angle difference does not exceed the predetermined first angle Thr1, or after adding the first fault flag, the control unit 20 can determine whether the second angle difference exceeds the predetermined second angle Thr2 (112).

[0086] If the judgment result of operation mode 112 is that the second angle difference exceeds the predetermined second angle Thr2, the control unit 20 may add a second fault flag (114). The second fault flag may indicate that the second auxiliary gear 13 may have damaged or missing teeth.

[0087] On the other hand, when the judgment result of operation mode 112 is that the second angle difference does not exceed the predetermined second angle Thr2, or after adding the second fault flag, the control unit 20 can sum up the fault flags (116). At this time, the control unit 20 can sum up the first fault flag and the second fault flag separately, or it can sum them up together.

[0088] The control unit 20 can determine whether the total number of fault flags exceeds the predetermined value Nthr (118).

[0089] If the judgment result of operation mode 118 is that the total number of fault flags does not exceed the predetermined value Nthr, then operation mode 100 can be moved and the next operation mode can be executed.

[0090] On the other hand, when the determination result of operation mode 118 is that the total number of fault flags exceeds a predetermined value Nthr, it can be determined that the steering angle sensor 10 is faulty (120). At this time, when the value of the total first fault flag exceeds a predetermined first value, the control unit 20 can determine that the steering angle sensor 10 is faulty due to damage or missing teeth of the first set gear 12. In addition, when the value of the total second fault flag exceeds a predetermined second value, the control unit 20 can determine that the steering angle sensor 10 is faulty due to damage or missing teeth of the second set gear 13.

[0091] The control unit 20 can warn the driver (122) that the steering angle sensor 10 has malfunctioned through the warning unit 30.

[0092] Figure 5 and Figure 6 A control method for a steering angle sensor fault detection device according to another embodiment is shown.

[0093] Reference Figure 5 and Figure 6The control unit 20 can receive the angle signal of the first auxiliary gear 12 from the first Hall IC chip 16 of the steering angle sensor 10, thereby detecting the angle (200) of the first auxiliary gear 12.

[0094] The control unit 20 can receive the angle signal of the second auxiliary gear 13 from the second Hall IC chip 17 of the steering angle sensor 10, thereby detecting the angle (202) of the second auxiliary gear 13.

[0095] The control unit 20 can calculate the first angle difference (204) between the angle of the first gear 12 at the current time point and the angle at a past time point.

[0096] The control unit 20 can calculate the second angle difference (206) between the angle of the second gear 13 at the current time point and the angle at a past time point.

[0097] The control unit 20 can calculate the first angle difference - second angle difference (208), which is the angle difference between the first angle difference and the second angle difference.

[0098] The control unit 20 can determine whether the first angle difference exceeds the predetermined first angle Thr1 (210).

[0099] If the judgment result of operation mode 210 is that the first angle difference exceeds the predetermined first angle Thr1, the control unit 20 may add a first fault flag (212). The first fault flag may indicate that the first auxiliary gear 12 may have damaged or missing teeth.

[0100] On the other hand, when the determination result of operation mode 210 is that the first angle difference does not exceed the predetermined first angle Thr1, or after adding the first fault flag, the control unit 20 can determine whether the second angle difference exceeds the predetermined second angle Thr2 (214).

[0101] If the judgment result of operation mode 214 is that the second angle difference exceeds the predetermined second angle Thr2, the control unit 20 may add a second fault flag (216). The second fault flag may indicate that the second auxiliary gear 13 may have damaged or missing teeth.

[0102] On the other hand, when the judgment result of operation mode 214 is that the second angle difference does not exceed the predetermined second angle Thr2, or after adding the second fault flag, the control unit 20 can determine whether the first angle difference - the second angle difference exceeds the predetermined third angle Thr3 (218).

[0103] If the judgment result of operation mode 218 is that the difference between the first angle difference and the second angle difference exceeds the predetermined third angle Thr3, then the control unit 20 may add a third fault flag (220). The third fault flag may indicate that the main gear 11 may have damaged or missing teeth. The third fault flag may also indicate that the first auxiliary gear 12 and / or the second auxiliary gear 13 may have damaged or missing teeth.

[0104] On the other hand, when the judgment result of operation mode 218 is that the difference between the first angle and the second angle does not exceed the predetermined third angle Thr3, or after adding the third fault flag, the control unit 20 can sum up the fault flags (222). At this time, the control unit 20 can sum up the first fault flag, the second fault flag and the third fault flag separately, or it can sum them up together.

[0105] The control unit 20 can determine whether the total number of fault flags exceeds the predetermined value Nthr (224).

[0106] If the judgment result of operation mode 224 is that the total number of fault flags does not exceed the predetermined value Nthr, then operation mode 200 can be moved and the next operation mode can be executed.

[0107] On the other hand, when the judgment result of operation mode 224 is that the total number of fault flags exceeds the predetermined value Nthr, it can be determined that the steering angle sensor 10 is faulty (226). At this time, when the value of the total first fault flag exceeds the predetermined first value, the control unit 20 can determine that the steering angle sensor 10 is faulty due to damage or missing teeth of the first auxiliary gear 12. In addition, when the value of the total second fault flag exceeds the predetermined second value, the control unit 20 can determine that the steering angle sensor 10 is faulty due to damage or missing teeth of the second auxiliary gear 13. In addition, the control unit 20 can determine that the steering angle sensor 10 is faulty due to damage or missing teeth of the main gear 11.

[0108] The control unit 20 can warn the driver via the warning unit 30 that the steering angle sensor 10 has malfunctioned (228).

[0109] Figure 7 A control method for a steering angle sensor fault detection device according to yet another embodiment is shown.

[0110] Reference Figure 7 The control unit 20 can receive the angle signal of the first auxiliary gear 12 from the first Hall IC chip 16 of the steering angle sensor 10, thereby detecting the angle (300) of the first auxiliary gear 12.

[0111] The control unit 20 can receive the angle signal of the second auxiliary gear 13 from the second Hall IC chip 17 of the steering angle sensor 10, thereby detecting the angle (302) of the second auxiliary gear 13.

[0112] The control unit 20 can calculate the first angle difference (304) between the angle of the first gear 12 at the current time point and the angle at a past time point.

[0113] The control unit 20 can calculate the second angle difference (306) between the angle of the second gear 13 at the current time point and the angle at a past time point.

[0114] The control unit 20 can calculate the first-second angle difference (308), which is the angle difference between the first angle difference and the second angle difference.

[0115] The control unit 20 can determine whether the first angle difference - the second angle difference exceeds the predetermined third angle Thr3 (310).

[0116] If the judgment result of operation mode 310 is that the difference between the first angle difference and the second angle difference exceeds the predetermined third angle Thr3, then the control unit 20 may add a fault flag (312). The fault flag may indicate that the main gear 11 may have damaged or missing teeth. The fault flag may also indicate that the first auxiliary gear 12 and / or the second auxiliary gear 13 may have damaged or missing teeth.

[0117] On the other hand, when the judgment result of operation mode 310 is that the first angle difference - the second angle difference does not exceed the predetermined third angle Thr3, or after adding a fault flag, the control unit 20 can determine whether the fault flag exceeds the predetermined value Nthr (314).

[0118] If the judgment result of operation mode 314 is that the fault flag does not exceed the predetermined value Nthr, then operation mode 300 can be moved and the next operation mode can be executed.

[0119] On the other hand, when the judgment result of operation mode 314 is that the fault flag exceeds the predetermined value Nthr, it can be judged that the steering angle sensor 10 is faulty (316).

[0120] The control unit 20 can warn the driver via the warning unit 30 that the steering angle sensor 10 has malfunctioned (318).

[0121] As described above, the disclosed invention can more effectively detect malfunctions caused by gear deformation or damage to the steering angle sensor.

Claims

1. A fault detection device for a steering angle sensor, comprising: The steering angle sensor includes a main gear that rotates with the steering wheel, a first auxiliary gear and a second auxiliary gear that mesh with the main gear while having a predetermined gear ratio with the main gear, and a first Hall IC chip for detecting the angle of the first auxiliary gear and a second Hall IC chip for detecting the angle of the second auxiliary gear. as well as The control unit determines the fault of the steering angle sensor based on the first angle difference between the current time point and the past time point of the first gear angle detected by the first Hall IC chip and the second angle difference between the current time point and the past time point of the second gear angle detected by the second Hall IC chip. The control unit counts the number of times that the first angle difference or the second angle difference is greater than a predetermined angle. When the counted number is greater than the predetermined number, the control unit determines that the steering angle sensor is faulty.

2. The fault detection device for the steering angle sensor according to claim 1, wherein, When the number of counts based on the first angle difference exceeds a predetermined number, the control unit determines that the steering angle sensor is malfunctioning due to damage to the teeth of the first auxiliary gear.

3. The fault detection device for the steering angle sensor according to claim 1, wherein, When the number of counts based on the second angle difference exceeds a predetermined number, the control unit determines that the steering angle sensor is malfunctioning due to damage to the teeth of the second auxiliary gear.

4. The fault detection device for the steering angle sensor according to claim 1, wherein, The control unit counts the number of times the first angle difference is greater than a predetermined angle, counts the number of times the second angle difference is greater than a predetermined angle, and sums up the counts for each. When the total count is greater than a predetermined count, it is determined that the fault is caused by damage to the gear of the steering angle sensor.

5. The fault detection device for the steering angle sensor according to claim 1, wherein, The control unit determines the fault of the steering angle sensor based on the first angle difference, the second angle difference, and the first angle difference minus the second angle difference, which is the angle difference between the first angle difference and the second angle difference.

6. The fault detection device for the steering angle sensor according to claim 5, wherein, The control unit counts the number of times the first angle difference is greater than a predetermined angle, counts the number of times the second angle difference is greater than a predetermined angle, and counts the number of times the first angle difference minus the second angle difference is greater than a predetermined angle. The control unit then sums up the counts for each angle difference. When the sum of the counts exceeds a predetermined number, the control unit determines that the failure is caused by damage to the gears of the steering angle sensor.

7. The fault detection device for the steering angle sensor according to claim 1, wherein, The control unit determines the fault of the steering angle sensor based on the first angle difference minus the second angle difference, which is the angle difference between the first angle difference and the second angle difference.

8. The fault detection device for the steering angle sensor according to claim 7, wherein, The control unit counts the number of times the first angle difference minus the second angle difference is greater than a predetermined angle, and sums the counted number of times. When the summed number of times is greater than the predetermined number of times, it is determined that the fault is caused by damage to the gear of the steering angle sensor.

9. A fault detection method for a steering angle sensor, wherein, The steering angle sensor includes a first auxiliary gear and a second auxiliary gear. The first and second auxiliary gears mesh with the main gear while having a predetermined gear ratio. The main gear rotates together with the steering wheel. The fault detection method for the steering angle sensor includes the following steps: Detect the angle of the first pair of gears; Detect the angle of the second auxiliary gear; Calculate the first angle difference between the current time point and the past time point of the first gear angle; Calculate the second angle difference between the current time point and a past time point for the second gear angle; and The steering angle sensor is determined to be faulty based on the first angle difference and the second angle difference, wherein the number of times the first angle difference or the second angle difference is greater than a predetermined angle is counted, and when the counted number is greater than the predetermined number, the steering angle sensor is determined to be faulty.

10. The fault detection method for the steering angle sensor according to claim 9, wherein, In the step of determining the fault of the steering angle sensor, when the number of counts based on the first angle difference is greater than a predetermined number, it is determined that the fault of the steering angle sensor is caused by damage to the teeth of the first auxiliary gear.

11. The fault detection method for the steering angle sensor according to claim 9, wherein, In the step of determining the fault of the steering angle sensor, when the number of counts based on the second angle difference is greater than a predetermined number, it is determined that the fault of the steering angle sensor is caused by damage to the teeth of the second auxiliary gear.

12. The fault detection method for the steering angle sensor according to claim 9, wherein, In the step of determining the fault of the steering angle sensor, the number of times the first angle difference is greater than a predetermined angle is counted, the number of times the second angle difference is greater than a predetermined angle is counted, and the counts of each are totaled. When the total count is greater than a predetermined count, it is determined that the fault is caused by damage to the gear of the steering angle sensor.

13. The fault detection method for the steering angle sensor according to claim 9, comprising the following steps: Further calculate the first angle difference - the second angle difference, which is the angle difference between the first angle difference and the second angle difference. The fault of the steering angle sensor is determined based on the first angle difference, the second angle difference, and the first angle difference minus the second angle difference.

14. The fault detection method for the steering angle sensor according to claim 13, wherein, In the step of determining the fault of the steering angle sensor, the number of times the first angle difference is greater than a predetermined angle is counted, the number of times the second angle difference is greater than a predetermined angle is counted, and the number of times the first angle difference minus the second angle difference is greater than a predetermined angle is counted. The counts of each are then totaled. When the total number of counts is greater than a predetermined number, the fault is determined to be caused by damage to the gear of the steering angle sensor.

15. The fault detection method for the steering angle sensor according to claim 9, wherein, In the step of determining the fault of the steering angle sensor, the fault of the steering angle sensor is determined based on the first angle difference - the second angle difference, which is the angle difference between the first angle difference and the second angle difference.

16. The fault detection method for the steering angle sensor according to claim 15, wherein, In the step of determining the fault of the steering angle sensor, the number of times the first angle difference minus the second angle difference is greater than a predetermined angle is counted, and the total number of counts is summed. When the total number of counts is greater than the predetermined number, it is determined that the fault is caused by damage to the gear of the steering angle sensor.

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