DEVICE AND METHOD FOR DETECTING STEERING INFORMATION

Abstract

Device for detecting steering information, wherein the device comprises the following: first to fourth torque sensors (410-440) designed to detect a relative rotation angle according to a distortion of a steering input shaft (100), a steering output shaft (200) and a torsion bar (300) arranged between the steering input shaft (100) and steering output shaft (200); first to fourth rotation angle sensors (510-540) designed to detect an absolute rotation angle of the steering input shaft (100) or steering output shaft (200); a first synchronization tester (610) designed to check synchronization states of output values ​​of the four torque sensors (410-440); a second synchronization tester (620) designed to check synchronization states of output values ​​of the four rotation angle sensors (510-540); a torque calculator (700) designed to calculate a torque value based on at least one of the output values ​​of the four torque sensors (410-440) according to test results of the first and second synchronization tester (610, 620); and a steering angle calculator (800) designed to calculate a steering angle based on at least one of the output values ​​of the four torque sensors (410-440) and at least one of the output values ​​of the four rotation angle sensors (510-540) according to test results of the first and second synchronization tester (610, 620).

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present disclosure relates to a device and a method for detecting steering information and in particular a device and a method in which a plurality of torque sensors and sensors for detecting a rotation angle of a steering shaft are provided to calculate steering information, such as a steering torque, etc., even if a fault occurs in some sensors. 2. Description of the state of the art

[0002] Generally, a power steering system is used in a vehicle to ensure steering stability by reducing the force required to move a steering wheel. Historically, hydraulic power steering (HPS) systems were widely used in vehicles, but nowadays electric power steering (EPS) systems are commonly installed. These are more environmentally friendly and assist the driver by using the rotational force of a motor, unlike the existing method that uses hydraulic pressure.

[0003] In such an EPS system, an electronic control unit (ECU) operates a motor according to the vehicle's driving conditions, which are detected by a speedometer, a torque sensor, and similar sensors. Accordingly, the EPS system provides a light and comfortable steering feel at low speeds, a heavier steering feel and sufficient directional stability at high speeds, and allows for rapid steering in emergencies, thus offering the driver optimal steering conditions.

[0004] An ECU of an existing EPS system measures a torque applied to a torsion bar and an absolute steering angle, i.e. a rotation measure of a steering input shaft (IS), by means of a first angular device for calculating an absolute steering angle and a second and third angular device for calculating a relative steering angle.

[0005] According to the existing method for detecting torque and steering angle, if a fault occurs in the first, second, or third angle sensor, it is not possible to calculate either a torque value or a steering angle. As a result, the power steering is not controlled, and the stability of a vehicle can be significantly impaired.

[0006] The closest related document to the application, EP 3 192 722 B1, describes a conventional device for detecting steering information and a corresponding method. The device of EP 3 192 722 B1 discloses first to fourth torque sensors designed to detect a relative angle of rotation due to distortion of a steering input shaft, a steering output shaft, and a torsion bar arranged between the steering input shaft and steering output shaft; and first to fourth angle of rotation sensors designed to detect an absolute angle of rotation of the steering input shaft or steering output shaft.The method of EP 3 192 722 B1 discloses: outputting information on relative rotation angles by first to fourth torque sensors according to the distortion of a torsion bar arranged between a steering input shaft and a steering output shaft; and outputting information on absolute rotation angles of the steering input shaft or steering output shaft by the first to fourth rotation angle sensors. SUMMARY OF THE INVENTION

[0007] Against this background, the present disclosure is intended to provide a device and a method for obtaining information needed for steering, even when a fault occurs in some sensors.

[0008] Furthermore, the present disclosure is intended to provide an electronic power steering (EPS) device, a steering information detection device, etc., in which a plurality of torque sensors and absolute angle sensors (rotational angle sensors) are provided, and it is determined whether sensor output values ​​are synchronized in such a way that the steering is controlled normally, even when a fault occurs in some sensors.

[0009] Furthermore, the present disclosure is intended to provide a device and a method for detecting an offset in the installation position of a sensor device on a steering shaft.

[0010] To solve the aforementioned problems, one embodiment provides a device for detecting steering information, wherein the device comprises: first to fourth torque sensors designed to detect a relative angle of rotation according to a deformation of a steering input shaft (IS), a steering output shaft (OS), and a torsion bar arranged between the steering input shaft and steering output shaft; first to fourth angle of rotation sensors designed to detect an absolute angle of rotation of the steering input shaft, respectively.to detect steering output shaft; characterized by a first synchronization tester designed to check synchronization states of output values ​​from the four torque sensors; a second synchronization tester designed to check synchronization states of output values ​​from the four rotation angle sensors; a torque calculator designed to calculate a torque value based on at least one of the output values ​​from the four torque sensors according to the determination results of the first and second synchronization testers; and a steering angle calculator designed to calculate a steering angle based on at least one of the output values ​​from the four torque sensors and at least one of the output values ​​from the four rotation angle sensors according to the determination results of the first and second synchronization testers.

[0011] Another embodiment provides a device for detecting steering information, wherein the device comprises: a torque sensor designed to detect a relative angle of rotation according to a deformation of a torsion bar arranged between a steering input shaft and a steering output shaft, characterized by an offset detection device having an interference element designed to project radially from a circumferential surface of the steering input shaft or steering output shaft, and an offset sensor designed to be positioned on a rotational element located at one end of the steering output shaft or steering output shaft.to be installed on the steering input shaft and to generate an output signal according to movement with respect to the interference element; and a torque calculator designed to calculate a torque applied to the torsion bar from the relative angle of rotation output by the torque sensor.

[0012] A further embodiment provides a method for detecting steering information, wherein the method comprises: outputting a relative rotation angle by first to fourth torque sensors according to a deformation of a torsion bar arranged between a steering input shaft and a steering output shaft; outputting an absolute rotation angle of the steering input shaft or...Steering output shaft through first to fourth rotation angle sensors; characterized by a first synchronization test process of checking synchronization states of output values ​​of the four torque sensors; a second synchronization test process of checking synchronization states of output values ​​of the four rotation angle sensors; a torque calculation process of calculating a torque value based on at least one of the output values ​​of the four torque sensors according to the results of the first synchronization test process; and a steering angle calculation process of calculating a steering angle based on at least one of the output values ​​of the four torque sensors and at least one of the output values ​​of the four rotation angle sensors according to the results of the first and second synchronization test processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and further aspects and advantages of the present disclosure are more evident from the following detailed description in conjunction with the accompanying drawings, in which: Fig. 1 is a diagram illustrating a device for detecting a steering angle and torque in a general electronic power steering (EPS) system; Fig. 2 a functional block diagram of a device for detecting steering information according to an embodiment of the present disclosure; Fig. 3 shows a detailed construction of a device for detecting steering information according to an embodiment of the present disclosure; Fig. 4 shows a detailed composition of an offset detection device used in an embodiment of the present disclosure; Fig.5 illustrates an overview flowchart of a method for detecting steering information according to an embodiment of the present disclosure; Fig. Figure 6 illustrates an overview flowchart of a method for detecting a deviation from an installation position according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF EXAMPLE EXECUTIONS

[0014] In the following, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Where possible, identical elements are identified by adding reference symbols to elements in each drawing, even if they are shown in different drawings. Furthermore, in the following description of the present disclosure, a detailed description of known functions and interpretations included herein is omitted if it is determined that such a description would further obscure the subject matter of the present disclosure.

[0015] Fig. Figure 1 is a diagram illustrating a general electric power steering (EPS) system, which is in contrast to the present disclosure.

[0016] An EPS system made of Fig.1 has a torque sensor, a first rotor 14 and a second rotor 20 and an electrical control unit (ECU) 60, which determines a reference steering angle based on information acquired by the torque sensor, verifies relative steering angles obtained by second and third angle devices 30 and 40, and determines a verified final absolute steering angle.

[0017] The first rotor 14 is connected to an input shaft (IS) 12, and the second rotor 20 is connected to an output shaft (OS) 18. The IS 12 is coupled to a steering wheel 10, which is provided in a driver's seat, and the OS 18 can be coupled to a lower steering system (for example, a gear drive) connected to tires. When the IS 12 is rotated by an external force, a rotational force from the IS 12 is transmitted to the OS 18 via a torsion bar 16, thus also rotating the OS 18.

[0018] The torsion bar 16 is provided between the first rotor 14 and the second rotor 20 to measure the deformation dimension between the IS12 and the OS 18.

[0019] A first angular device 50 provides the ECU 60 with an absolute steering angle, which is a rotation angle of the first rotor 14. The first angular device 50 can be arranged parallel to the first rotor 14.

[0020] The second and third angle devices 30 and 40 can be arranged under the first rotor 14 and provide the ECU 60 with relative steering angles of the first and second rotors 14 and 20 respectively.

[0021] The ECU 60 determines a reference steering angle using the steering angles obtained from the first to third angular devices 30, 40, and 50, and a Vernier algorithm, and tracks the movement of the first rotor 14 based on the determined reference steering angle. Regarding the movement of the first rotor 14, the first and second absolute steering angles can each be calculated using the reference steering angle and the relative steering angles obtained from the second and third angular devices 30 and 40, respectively.

[0022] Here, the second angle device 30 and the third angle device 40 can be referred to as a first torque sensor and a second torque sensor, and the first angle device 50 can be referred to as a steering angle sensor or a rotation angle sensor.

[0023] Meanwhile, if there is a fault in at least one of the first to third angle devices in the EPS system, which determines the composition as in Fig. As shown in Figure 1, it is not possible to calculate either a torque value or a steering angle. As a result, the power steering is not controlled and the stability of the vehicle can be problematic.

[0024] In particular, in an autonomous vehicle and the like, which is currently under development, a steering system will not be used as an auxiliary steering system to support manual steering control and will be operated automatically to steer the vehicle independently without steering input from a driver.

[0025] Therefore, safety in a steering system used in such autonomous vehicles and the like can remain problematic, as the steering control is completely shut down if a fault occurs in an angle device, and it is not possible to measure either a torque value or a steering angle, as mentioned above.

[0026] Furthermore, a sensor, which is an angled device installed on both an IS and an OS (steering system), is secured by tooling (crimping). Therefore, when sudden steering maneuvers or strong steering forces are applied, a misalignment problem sometimes occurs; that is, the center point of the sensor shifts due to damage to an installation component caused by the impact.

[0027] Accordingly, one embodiment of the present disclosure proposes a composition comprising four torque sensors for detecting a torque and four rotation angle sensors for detecting an absolute rotation angle in preparation for a fault of a first to third angle device, detecting by monitoring whether output values ​​of the four torque sensors are synchronized and whether output values ​​of the four rotation angle sensors are synchronized, a torque sensor and a rotation angle sensor in which a fault has occurred, and excluding an output value of the sensor in which a fault has occurred from the calculation of a torque value and a steering angle.

[0028] Fig. Figure 2 is a functional block diagram of a device for detecting steering information according to an embodiment of the present disclosure.

[0029] As in Fig.As shown in Figure 2, a device for detecting steering information according to an embodiment of the present disclosure can include first to fourth torque sensors 410 to 440, which are four torque sensors for detecting a relative rotation angle according to a deformation of a torsion bar arranged between the steering input shaft and a steering output shaft, and first to fourth rotation angle sensors 510 to 540, which are four rotation angle sensors of the IS orOS comprises a first synchronization tester 610 for checking the synchronization states of output values ​​from the four torque sensors, a second synchronization tester 620 for checking the synchronization states of output values ​​from the four rotation angle sensors 510 to 540, a torque calculator 700 for calculating a torque value based on at least one of the output values ​​from the four torque sensors according to the determination results of the first and second synchronization testers 610 and 620, and a steering angle calculator 800 for calculating a steering angle based on at least one of the output values ​​from the four torque sensors and at least one of the output values ​​from the four rotation angle sensors according to the determination results of the first and second synchronization testers 610 and 620.

[0030] In other words, the device for detecting steering information according to this embodiment of the present disclosure has four relative rotation angle sensors for calculating a torque, four rotation angle sensors for measuring an absolute rotation angle of a steering shaft, determines errors of a sensor by determining whether output values ​​of the respective sensors are identical, and calculates a torque value and a steering angle using only output values ​​from sensors in a normal state.

[0031] This description uses four torque sensors and four rotational angle sensors as an example; however, the number of torque sensors and rotational angle sensors is not limited to this. In other words, the present disclosure includes an embodiment that has a plurality of torque sensors and rotational angle sensors and calculates a torque and a steering angle by determining whether a plurality of sensors are synchronized. For ease of understanding, a case in which four torque sensors and four rotational angle sensors are present is described below.

[0032] Fig. Figure 3 shows a detailed construction of a device for detecting steering information according to an embodiment of the present disclosure.

[0033] As in Fig.Figure 3 shows a steering shaft comprising a steering input shaft 100 connected to a steering wheel or steering column, a steering output shaft 200 coupled to a gear transmission or the like, and a torsion bar 300, which is a deformation means attached between the steering input shaft 100 and the steering output shaft 200.

[0034] A first input-side rotary element 120 and a second input-side rotary element 130 are attached to one end of the steering input shaft 100.

[0035] The two input-side rotational elements 120 and 130 rotate with the steering input shaft 100 and an offset detection device, which is located below with reference to Fig. 4, which is described in detail, may also be present to detect a deviation from an initial installation position, that is, a center position.

[0036] The first and second input-side rotating elements 120 and 130 can also be referred to as rotors and can each be circular flat plate elements having N and M teeth or holes. The first and second input-side rotating elements 120 and 130 allow adjacent sensors to calculate the rotation angle of the steering input shaft 100 by measuring the number of its rotations.

[0037] Here, the first input-side rotation element 120 is used together with an output-side rotation element 220, which is described below, for the first to fourth torque sensors 410 to 440 to measure information of a relative rotation angle.

[0038] Simultaneously, the output-side rotating element 220 is attached to one end of the steering output shaft 200 and can therefore also be referred to as an output-side rotor. As with the first input-side rotating element 120, the output-side rotating element 220 can be a circular, flat plate element with N teeth or holes.

[0039] The first input-side rotational element 120 and the output-side rotational element 220, which are arranged opposite each other with the torsion bar 300 interposed between them, are intended to measure the degree of relative rotation between the steering input shaft 100 and the steering output shaft 200.

[0040] In other words, the first to fourth torque sensors 410 to 440, arranged around the first input-side rotational element 120 and the output-side rotational element 220, output a difference in the rotation angle, that is, information about the relative rotation angle, between the first input-side rotational element 120 and the output-side rotational element 220, which is temporarily caused by deformation of the torsion bar 300. The output information about the relative rotation angle is used by the torque calculator 700 to calculate a torque value, as described below.

[0041] Furthermore, the second input-side rotating element 130, which is arranged on the steering input shaft 100, is used as a means for measuring an absolute rotation angle of the steering input shaft 100.

[0042] In other words, the first to fourth rotation angle sensors 510 to 540, arranged around the second input-side rotation element 130, output a rotation angle of the second input-side rotation element 130, that is, information about the absolute rotation angle of the steering input shaft 100. The steering angle calculator 800 calculates a final steering angle according to the Vernier algorithm by using the output information about the absolute rotation angle and the previously mentioned information about the relative rotation angle.

[0043] At the same time, according to this embodiment of the present disclosure, the four torque sensors, that is, the first torque sensor 410, the second torque sensor 420, the third torque sensor 430 and the fourth torque sensor 440, are arranged around the first input-side rotational element 120 and the output-side rotational element 220.

[0044] All four torque sensors 410 to 440 can have the same shape and each can have an A-sensor to measure a rotation angle of the first input-side rotation element 120 and a B-sensor to measure a rotation angle of the output-side rotation element 220.

[0045] In other words, the first torque sensor 410 has an A-sensor 410A arranged around the first input-side rotating element 120 and a B-sensor 410B arranged around the output-side rotating element 220.

[0046] The first torque sensor 410 can use a difference between measured values ​​between the A-sensor 410A and the B-sensor 410B to calculate information about a relative rotation angle, which indicates a relative rotation angle between the steering input shaft 100 and the steering output shaft 200.

[0047] In other words, since the first input-side rotational element 120 and the output-side rotational element 220 have the same shape, the A-sensor 410A and the B-sensor 410B output the same value when no torque is applied to the torsion bar 300, and the A-sensor 410A and the B-sensor 410B output different values ​​when a difference in the rotation dimension between the steering input shaft 100 and the steering output shaft 200 is temporarily caused by a torque applied to the torsion bar 300.

[0048] Therefore, any torque sensor can determine a relative rotation angle by comparing a difference value (Diff.), which is a difference in the output value between an A-sensor and a B-sensor, with a current value.

[0049] Furthermore, the four torque sensors 410 to 440 can be distributed around a rotating element. As in Fig.As shown in Figure 3B, each of the four torque sensors 410 to 440 can be spaced 90 degrees apart, but this arrangement is not limited to that. Torque sensors can be arranged at other angles, depending on the number of sensors.

[0050] At the same time, the four rotation angle sensors, that is, the first rotation angle sensor 510, the second rotation angle sensor 520, the third rotation angle sensor 530 and the fourth rotation angle sensor 540, are distributed and arranged around the second input-side rotation element 130.

[0051] In other words, the four rotation angle sensors 510 to 540 can be distributed and arranged around the second input-side rotation element 130. As shown in Fig.As shown in Figure 3C, each of the four rotation angle sensors 510 to 540 can be spaced 90 degrees apart, but this arrangement of the four rotation angle sensors 510 to 540 is not limited to this. Rotation angle sensors can be arranged at other angles, corresponding to the number of sensors.

[0052] Each rotation angle sensor detects the rotation measure, that is, an absolute rotation angle, of the second input-side rotation element 130.

[0053] Such a rotation angle sensor can output a pulse width modulation (PWM) signal proportional to the rotation measure of the second input-side rotation element 130.

[0054] It was described above that rotation elements and rotation angle sensors for measuring the absolute angle of a steering shaft are located on the IS side. However, the arrangement of the rotation elements and rotation angle sensors is not limited to this, and they can also be located on an OS side.

[0055] The torque sensors and rotation angle sensors described above can also be referred to as integrated torque circuits (ICs) and Hall ICs.

[0056] At the same time, a rotation angle sensor outputs an absolute rotation angle of a steering shaft, and the output absolute rotation angle has a value of 360 degrees or less.

[0057] In other words, a rotation angle sensor is not able to output a final steering angle that reflects multiple rotations exceeding 360 degrees, and therefore an output value from a torque sensor is additionally used to calculate a final steering angle information.

[0058] N, which is the number of teeth / holes of the second input-side rotational element 130 for measuring an absolute rotation angle, differs from M, which is a number of teeth / holes of the first input-side rotational element 120, which is a target of the torque sensor.

[0059] Therefore, if both information about the absolute rotation angle, which is an output value of the rotation angle sensor, and an output value of the torque sensor are applied to a Vernier algorithm, it is possible to measure a final steering angle that takes multiple rotations into account.

[0060] For this purpose, the device for detecting steering information according to this embodiment can have a plurality of angle followers, even if not shown in the drawings.

[0061] According to this embodiment, reference steering angle information, which is information about several rotation angles, is first calculated using an absolute steering angle measured by the rotation angle sensors, another rotation angle information measured by the torque sensors, and the Vernier algorithm.

[0062] Next, values ​​output by the torque and rotation angle sensors can be monitored over time, and a final steering angle can be continuously calculated by applying the output values ​​to the calculated reference steering angle. The numerous angle followers are provided for this purpose.

[0063] At the same time, the first synchronization tester 610 according to this embodiment functions to check the synchronization states of output values ​​of the four torque sensors.

[0064] In other words, the first synchronization tester 610 works to determine a synchronized torque sensor and a non-synchronized torque sensor by comparing values ​​output by the four torque sensors 410 to 440 in multiple channels or in multiple ways.

[0065] Here, all synchronized torque sensors essentially provide the same output value and can be considered to be in a normal state. A non-synchronized torque sensor produces an output value that differs from the output values ​​of other torque sensors and can be considered to be in an anomalous or faulty state.

[0066] For example, if the output values ​​of the first to third torque sensors 410 to 430 are essentially the same and only one output value of the fourth torque sensor 440 is different, the first to third torque sensors 410 to 430 are determined to be synchronized torque sensors in the normal state and the fourth torque sensor 440 is determined to be a non-synchronized torque sensor in the fault state.

[0067] In other words, each torque sensor has an A-sensor for detecting the rotation of the steering input shaft 100 and a B-sensor for detecting the rotation of the steering output shaft 200. The first synchronization tester 610 determines that an i-th torque sensor (i = 1, 2, 3 and 4) and a j-th torque sensor (j = 1, 2, 3 and 4; i≠j) are synchronized only if a difference between an output value of the A- or B-sensor of the i-th torque sensor (i = 1, 2, 3 and 4) and an output value of the A- or B-sensor of the j-th torque sensor (j = 1, 2, 3 and 4; i≠j) is less than or equal to a threshold value.

[0068] The operation of the first synchronization tester 610 is described in more detail below as an example.

[0069] First, the first synchronization tester 610 compares an output value of the A-sensor 410A of the first torque sensor 410 and an output value of an A-sensor 420A of the second torque sensor 420, or compares an output value of the B-sensor 410B of the first torque sensor 420 and an output value of the B-sensor 420B of the second torque sensor 420 (Sync. test (1A-2A) or Sync. test (1B-2B)).

[0070] Similarly, the first synchronization tester 610 compares an output value of the A-sensor 430A of the third torque sensor 430 and an output value of an A-sensor 440A of the fourth torque sensor 440, or compares an output value of a B-sensor 430B of the third torque sensor 430 and an output value of a B-sensor 440B of the fourth torque sensor 420 (Sync. test (3A-4A) or Sync. test (3B-4B)).

[0071] Next, the first synchronization tester 610 finally checks synchronization among the four torque sensors 410 to 440 by comparing a comparison result between the output values ​​of the first and second torque sensors 410 and 420 and a comparison result between the output values ​​of the third and fourth torque sensors 430 and 440 (Sync. test ((1A-2A)-(3A-4A)) or Sync. test ((1B-2B)-(3B-4B))).

[0072] Alternatively, with regard to two or more synchronized rotation angle sensors, determined by comparing the output values ​​of an A-sensor and a B-sensor, the first synchronization tester 610 can determine information about relative rotation angles between the output values ​​of A-sensors and B-sensors and identify a torque sensor as being in a fault condition if it outputs different information about relative rotation angles. In other words, the first synchronization tester 610 can initially compare the output values ​​of each torque sensor based on an IS or OS rotation angle, and subsequently compare information about relative rotation angles of torque sensors determined to be in the normal state, thereby ultimately determining whether a torque sensor is in the normal state or in the fault condition.

[0073] Independently of or in addition to such a synchronization test, the first synchronization tester 610 can determine whether information about relative rotation angles of the respective torque sensors 410 to 440, that is, difference values ​​between output values ​​of A-sensors and B-sensors of the respective torque sensors 410 to 440, have essentially the same value.

[0074] In other words, the first synchronization tester 610 compares information about the relative rotation angles of the first torque sensor 410, that is, a difference value between the output values ​​of the A and B sensors 410A and 410B of the first torque sensor 410 (diff. angle (1B-1A)), and a difference value between the output values ​​of the A and B sensors 420A and 420B of the second torque sensor 420 (diff. angle (2B-2A)).

[0075] Similarly, the first synchronization tester 610 compares a difference value between output values ​​of the A and B sensors 430A and 430B of the third torque sensor 430 (diff. angle (3B-3A)) and a difference value between output values ​​of the A and B sensors 440A and 440B of the fourth torque sensor 440 (diff. angle (4B-4A)).

[0076] Through this process, the first synchronization tester 610 can determine whether the four torque sensors 410 to 440 are synchronized, that is, whether one torque sensor is in the normal state and one torque sensor is in the anomalous (fault) state.

[0077] The second synchronization tester 620 according to this embodiment functions to check the synchronization states of output values ​​of the four rotation angle sensors 510 to 540.

[0078] In other words, the second synchronization tester 620 functions to determine a synchronized rotation angle sensor and a non-synchronized rotation angle sensor by comparing values ​​output by the four rotation angle sensors 510 to 540 in multiple channels or in multiple ways.

[0079] Here, all synchronized rotation angle sensors essentially provide the same output value (information about absolute rotation angles) and can be considered to be in a normal state. A non-synchronized rotation angle sensor produces an output value that differs from the output values ​​of other rotation angle sensors and can be considered to be in an anomalous or faulty state.

[0080] For example, if the output values ​​of the first to third rotation angle sensors 510 to 530 are essentially the same and only one output value of the fourth rotation angle sensor 540 is different, the first to third rotation angle sensors 510 to 530 are determined to be synchronized rotation angle sensors in the normal state and the fourth rotation angle sensor 540 is determined to be a non-synchronized rotation angle sensor in the fault state.

[0081] Through this process, the second synchronization tester 620 can determine whether the four rotation angle sensors 510 to 540 are synchronized, that is, whether one rotation angle sensor is in the normal state and one rotation angle sensor is in the anomalous (fault) state.

[0082] The torque calculator 700 according to this embodiment functions to calculate a torque value based on at least one of the output values ​​of the four torque sensors 410 to 440 according to determination results of the first synchronization tester 610.

[0083] In particular, the torque calculator 700 calculates a torque that is applied to the torsion bar 300, based on an output value, that is, information about relative rotation angles, from synchronized torque sensors that are determined by the first synchronization tester 610 to be in the normal state.

[0084] For example, the Torque Calculator 700 can calculate a torque based on information about the mean relative rotation angles of torque sensors that have been determined to be synchronized by the first synchronization tester 610. In other words, the Torque Calculator 700 can calculate a torque using information about the relative rotation angle of a single torque sensor if that single torque sensor has been determined to be synchronized, and it can calculate a torque value using the mean of the relative rotation angle information from N torque sensors if N torque sensors have been determined to be synchronized.

[0085] In other words, the torque calculator 700 can determine, with respect to each of two or more synchronized torque sensors identified by the first synchronization tester 610, a difference value between the output values ​​of an A-sensor and a B-sensor as a relative rotation angle of the corresponding torque sensor, and calculate a torque value based on an average of information about the relative rotation angles of the two or more torque sensors.

[0086] Furthermore, if two or more synchronized torque sensors are present, the Torque Calculator 700 can average the output values ​​of the two or more torque sensors in the normal state and calculate a torque value based on the average to improve data accuracy.

[0087] In this embodiment, predetermined priority ranks can be assigned to the four torque sensors, and then output values ​​from the torque sensors can be used selectively according to the priority ranks.

[0088] For example, priority ranks can be assigned to the first to fourth torque sensors 410 to 440, the first to third torque sensors 410 to 430 can be in the normal state, and the fourth torque sensor 440 can be in the fault state. In this case, the output values ​​of the two torque sensors with high priority ranks, i.e., the first torque sensor 410 and the second torque sensor 420, can be averaged, and a torque value can be calculated based on the average.

[0089] It is obvious that if only one torque sensor is determined by the first synchronization tester 610 to be in the normal state, a torque value can be calculated from only one output value of the torque sensor.

[0090] Here, output values ​​or average values ​​from torque sensors and corresponding torque values ​​can be provided in the form of a table, and it is possible to calculate a torque value according to output values ​​or an average value by referring to the table.

[0091] Based on the calculated torque value, a steering assist system controller can calculate an auxiliary current applied to a steering motor and assist the steering.

[0092] Table 1 below is an example of a torque calculation method depending on whether four torque sensors are synchronized in this embodiment; however, the torque calculation method is not limited to Table 1. [Table 1] Number of cases Torque sensor 1 Torque sensor 2 Torque sensor 3 Torque sensor 4 Base value for torque calculation (differential angle) 1 A mistake ◯ ◯ ◯ X Use of the mean of the difference from TS 1 and the difference from TS 2. 2 ◯ ◯ X ◯ Use of the mean of the difference from TS 1 and the difference from TS 2. 3 ◯ X ◯ ◯ Use of the mean of the difference from TS 1 and the difference from TS 3. 4 X ◯ ◯ ◯ Use of mean of difference from TS 2 and difference from TS 3 5 Two errors ◯ ◯ X X Use of the mean of the difference from TS 1 and the difference from TS 2. 6 ◯ X ◯ X Use of the mean of the difference from TS 1 and the difference from TS 3. 7 ◯ X X ◯ Use of the mean of the difference from TS 1 and the difference from TS 4. 8 X ◯ ◯ X Use of mean of difference from TS 2 and difference from TS 3 9 X ◯ X ◯ Use of mean of difference from TS 2 and difference from TS 4 10 X X ◯ ◯ Use of mean of difference from TS 3 and difference from TS 4 11 Three mistakes ◯ X X X Using the differential output value from TS 1 12 X ◯ X X Using the differential output value from TS 2 13 X X ◯ X Using the differential output value from TS 3 14 X X X ◯ Using the differential output value from TS 4 15 Four mistakes X X X X Output sensor error 16 No error ◯ ◯ ◯ ◯ Use of the mean of the difference from TS 1 and the difference from TS 2.

[0093] At the same time, the torque calculator 700 can calculate a torque value based on a torque sensor group.

[0094] For example, torque sensors can be classified into a variety of A-sensors. For example, four torque sensors can be classified into two torque sensor groups. In other words, the first torque sensor 410 and the second torque sensor 420 can be classified as a first torque sensor group, and the third torque sensor 430 and the fourth torque sensor 440 can be classified as a second torque sensor group.

[0095] In this case, the torque calculator 700 can calculate a torque value applied to the torsion bar 300 using information about the relative rotation angles of torque sensors belonging to a torque sensor group selected after checking the synchronization status of the torque sensor group according to a determination by the first synchronization tester 610. In other words, the torque calculator 700 can calculate a torque value using either the first or the second torque sensor group.

[0096] A torque sensor group used to calculate a torque value can be a group in which all synchronization states of one or more torque sensors are determined to be the normal state. For example, the first synchronization checker 610 can determine whether each torque sensor is synchronized using the procedure described above. If the third torque sensor 430 is determined to be in the fault state and the other torque sensors are determined to be in the normal state, the torque calculator 700 can exclude information about the relative rotation angles of the second torque sensor group, which has the third torque sensor 430 in the fault state, and calculate a torque value using only the information about the mean relative rotation angles of the first torque sensor 410 and the second torque sensor 420 contained in the first torque sensor group.

[0097] In another example, if a large number of torque sensor groups are selected, only the torque sensor group with the highest priority rank according to predetermined priority ranks can be used to determine a torque value.

[0098] At the same time, the steering angle calculator 800 according to this embodiment functions to calculate a steering angle based on at least one of the output values ​​of the four torque sensors 410 to 440 and at least one of the output values ​​of the four rotation angle sensors 510 to 540 according to determination results of the first and second synchronization tester 610 and 620.

[0099] In particular, the steering angle calculator 800 calculates a final steering angle based on output values ​​from one or two torque sensors, which are determined by the first synchronization tester 610 to be in the normal state, and output values ​​from one or more rotation angle sensors, which are determined by the second synchronization tester 620 to be in the normal state.

[0100] Here, output values ​​from torque sensors used by the steering angle calculator 800 can be an output value from only one torque sensor or an average of outputs from two torque sensors in the normal state.

[0101] Similarly, output values ​​from rotation angle sensors used by the steering angle calculator 800 can be an output value from one of the rotation angle sensors in the normal state or an average of outputs from two rotation angle sensors in the normal state.

[0102] As described above, a rotation angle sensor outputs an absolute rotation angle of a steering shaft, which has a value of 360 degrees or less, but is not able to output information about a final steering angle that reflects multiple rotations exceeding 360 degrees.

[0103] Therefore, the steering angle calculator 800 can calculate a final steering angle, taking multiple rotations into account, by applying information about absolute rotation angles, which is an output value from a rotation angle sensor, together with an output value from a torque sensor to the Vernier algorithm.

[0104] Even in this case, it is possible to assign priority ranks to four rotation angle sensors and then selectively use the output values ​​of the rotation angle sensors according to the priority ranks.

[0105] For example, priority ranks can be assigned to the first through fourth rotation angle sensors 510 to 540, the first through third rotation angle sensors 510 to 530 can be in the normal state, and the fourth rotation angle sensor 540 can be in the fault state. In this case, an output value from the single rotation angle sensor 510, which has the highest priority rank, can be used, or output values ​​from the first rotation angle sensor 510 and the second rotation angle sensor 520, which are two rotation angle sensors with high priority ranks, can be averaged, and a steering angle value can be calculated based on the output value of the single rotation angle sensor 510 or the average value.

[0106] The steering assist system performs steering control based on the calculated steering angle value.

[0107] Table 2 below shows an example of a steering angle calculation method depending on whether four torque sensors are synchronized and whether four rotation angle sensors are synchronized in this embodiment; however, the steering angle calculation method is not limited to Table 2 (in Table 2, TS denotes a torque sensor, AS denotes a rotation angle sensor, O denotes the normal state, and X denotes a fault state). [Table 2] TS 1 TS 2 TS 3 TS 4 AS 1 AS 2 AS 3 AS 4 Base value for steering angle calculation ◯ ◯ ◯ × ◯ ◯ ◯ × Average of the difference from TS 1 and the difference from TS 2 + output value from AS 1 ◯ ◯ ◯ × × ◯ × Average of the difference from TS 1 and the difference from TS 2 + output value from AS 2 ◯ ◯ ◯ × × × ◯ ◯ Average of the difference from TS 1 and the difference from TS 2 + output value from AS 3 ◯ ◯ ◯ × × × × ◯ Average of the difference from TS 1 and the difference from TS 2 + output value from AS 4 ◯ ◯ ◯ × × × × × It is possible to calculate relative angles, but impossible to output steering angles. × ◯ ◯ ◯ × ◯ ◯ × Average of the difference from TS 2 and the difference from TS 3 + output value from AS 1

[0108] At the same time, an error output unit 910 can output a sensor error signal if the first or second synchronization tester 610 or 620 determines that an error has occurred in all of the four torque sensors 410 to 440 or all of the four rotation angle sensors 510 to 540.

[0109] In particular, if the first synchronization tester 610 determines that a fault has occurred in all four torque sensors 410 to 440, a torque sensor fault signal will be output. In this case, it is not possible to calculate either a torque value or a steering angle.

[0110] Simultaneously, if the second synchronization tester 620 determines that a fault has occurred in all four rotation angle sensors 510 to 540, a rotation angle sensor fault signal will be output. In this case, it is possible to calculate a torque value, but not a steering angle.

[0111] As described above, four torque sensors and four rotation angle sensors are used, and after determining whether the output value of each sensor is synchronized, a torque and a steering angle are calculated accordingly. Therefore, even if a fault occurs in some sensors, it is possible to calculate a normal torque and steering angle, and thus steering control is possible.

[0112] Fig. Figure 4 shows a detailed composition of an offset sensor used in an embodiment of the present disclosure.

[0113] As described above, one or more rotating elements are attached to the steering input shaft and the steering output shaft to detect a torque or a rotation angle.

[0114] Such a rotating element is attached to one IS and one OS, which are steering systems. When sudden steering maneuvers are performed and a strong steering force is applied to the steering shaft, a misalignment problem sometimes occurs; that is, the center point or initial installation position of a sensor is altered due to damage to a rotating element and a component of the steering shaft installation caused by the impact.

[0115] To solve the problem, the device for detecting steering information according to this embodiment can further incorporate an offset detection device 100 as described in Fig. 4 shown.

[0116] In particular, a device for detecting steering information according to the embodiment can consist of Fig.4 a torque sensor (not shown) for detecting a relative rotation angle according to a deformation of the torsion bar arranged between the steering input shaft and the steering output shaft, the offset detection device 1100, which has an interference element 1110 projecting radially from a circumferential surface of the steering input shaft or steering output shaft, and an offset sensor 1120, which is installed on a rotation element 130 attached to one end of the steering output shaft or IS and generates an output signal according to movement with respect to the interference element 1110, and a torque calculator, which calculates a torque applied to the torsion bar from the relative rotation angle output by the torque sensor.

[0117] Here, the offset detection device 1100 according to this embodiment can include the interference element 1110, which projects radially from a circumferential surface of the steering input shaft or steering output shaft, and the offset sensor 1120, which is installed on the rotation element 130, which is attached to one end of the steering input shaft or steering output shaft and generates an output signal according to a movement with respect to a projecting part.

[0118] The offset sensor 1120 can be a light barrier that generates different output signals according to the relative movement of the interference element 1110, and the offset detection device 1100 can detect a deviation of the rotation element 130 from an initial installation position on the steering input shaft or steering output shaft.

[0119] In particular, as in Fig.As shown in Figure 4, a projecting part, which extends radially by a certain distance from the circumferential surface of the steering input shaft, is formed as the interference element 1110 near the rotation element 130, which is attached to one end of the steering input shaft 100.

[0120] At the same time, the offset sensor 1120 in the form of a light barrier, consisting of a light transmitting device 1122 and a light receiving device 1124, is installed on a surface of the rotating element 130, and the interference element 1110 is arranged to run between the light transmitting device 1122 and the light receiving device 1124 of the offset sensor 1120 when the rotating element 130 does not deviate from an installation position on the steering input shaft.

[0121] For example, if the interference element 1110 is initially positioned in a normal state between the light-transmitting device 1122 and the light-receiving device 1124, the interference element 1110 will deviate from the gap between the light-transmitting device 1122 and the light-receiving device 1124 if the rotating element 130 deviates from its installation position on the steering shaft. Therefore, the offset sensor 1120 outputs a signal that differs from a signal in the initial state.

[0122] With the offset detection device 1100 it is possible to detect a deviation of the rotation element 130 from the installation position on the steering shaft, i.e. an offset of the center point of a sensor.

[0123] Fig. Figure 5 illustrates an overview flowchart of a method for detecting steering information according to an embodiment of the present disclosure.

[0124] With reference to Fig.5 discloses a method for detecting steering information according to an embodiment of the present disclosure, a process in which first to fourth torque sensors output information about relative rotation angles according to a deformation of a torsion bar arranged between a steering input shaft and a steering output shaft (S1310), a process in which first to fourth rotation angle sensors output information about absolute rotation angles of the steering input shaft orSteering output shaft output (S1312), a first synchronization test operation of checking synchronization states of output values ​​of the four torque sensors (S1320), a second synchronization test operation of checking synchronization states of output values ​​of the four rotation angle sensors (S1322), a torque calculation operation of calculating a torque value based on at least one of the output values ​​of the four torque sensors according to results of the first synchronization test operation, and a steering angle calculation operation of calculating a steering angle based on at least one of the output values ​​of the four torque sensors and at least one of the output values ​​of the four rotation angle sensors according to results of the first and second synchronization test operation.

[0125] In particular, the torque calculation process includes a process of determining whether one or more torque sensors are determined to be in the normal state in the first synchronization check process, and then outputting an error signal if no torque sensor is in the normal state (S1350), and a process of calculating a torque value using output values, that is, information about relative rotation angles, from torque sensors in the normal state if one or more torque sensors are in the normal state (S1340 and S1360).

[0126] As described above, if two or more sensors are in the normal state, an average of the output values ​​from two torque sensors that have high priority ranks, or an output value from one of the torque sensors in the normal state, can be used to calculate a torque value.

[0127] Furthermore, the steering angle calculation process includes a process of determining whether one or more rotation angle sensors are determined to be in the normal state in the second synchronization check process (S1332), a process of outputting an error signal if no rotation angle sensor is in the normal state (S1350), and a process of calculating a steering angle value using output values, i.e., information about absolute rotation angles, from rotation angle sensors in the normal state, and the output values, i.e., information about relative rotation angles, of the torque sensors in the normal state when one or more rotation angle sensors are in the normal state (S1342 and S1370).

[0128] As described above, if two or more rotation angle sensors are in the normal state, it is possible to use an average of the output values ​​of two rotation angle sensors that have high priority ranks, or an output value of one of the rotation angle sensors in the normal state.

[0129] Fig. Figure 6 illustrates an overview flowchart of a method for detecting a deviation from an installation position according to an embodiment of the present disclosure.

[0130] A method for detecting a deviation of a sensor device from an installation position on a steering shaft, as in Fig. Figure 6 illustrates how, together with the procedure of detecting steering information, this can be done as described in... Fig.5 is illustrated. However, the deviation detection method is used not only in conjunction with the steering information detection method but also independently.

[0131] In other words, the deviation detection method can be a process of detecting deviation of the rotational element 130 from an initial installation position on the steering input shaft or steering output shaft by means of the offset detection device 1100, as described in Fig. Figure 4 shows the interference element 1110, which projects radially from a circumferential surface of the steering input shaft or steering output shaft, and an offset sensor 1120, which is installed on the rotation element 130, which is attached to one end of the steering input shaft or steering output shaft and which generates an output signal according to movement with respect to the interference element 1110.

[0132] In particular, as in Fig.Figure 6 shows that an output value of the offset sensor 1120 described above is measured at certain times (S1410).

[0133] Next, it is determined whether an output value of the offset sensor 1120 has changed compared to an output value from a previous time (S1420), and an installation position deviation error (that is, a sensor center offset error) is output if the output value has changed (S1430).

[0134] In other words, a detected output value of the offset sensor 1120 is incorporated into the offset device 1100 with the assembly consisting of Fig.4. The output value is the same as a previous time without change if there is no offset (deviation) between a sensor rotation element and an initial installation position on a steering shaft, and an output value of the offset sensor 1120 is changed if there is an offset (deviation) between the sensor rotation element and the initial installation position on the steering shaft.

[0135] Therefore, by determining whether an output value of the offset sensor 1120 is changed at certain times as described above, it is detected whether the offset (deviation) between the sensor rotation element and the initial installation position on the steering shaft occurs, and a warning signal (error signal) is generated accordingly.

[0136] If there is an offset (deviation) between the sensor rotation element and its initial installation position on the steering shaft, it is not possible to obtain accurate steering information (steering torque and steering angle). Therefore, it is necessary to adjust the installation position of the sensor rotation element on the steering shaft.

[0137] As described above according to the embodiments of the present disclosure, it is possible to obtain the steering torque, steering angle information, etc., necessary for steering in a normal manner, even if a fault occurs in some of the sensors used in the EPS system.

[0138] In particular, a large number of torque sensors and absolute angle sensors (rotational angle sensors) are used, and after determining whether the output values ​​of the corresponding sensors are synchronized, a torque and a steering angle are calculated accordingly. Therefore, it is possible to calculate a torque and a steering angle and to control the steering accordingly even if a fault occurs in some sensors.

[0139] Furthermore, according to another embodiment of the present disclosure, it is possible to detect a deviation of a rotational element from an installation position on a steering shaft, i.e., an offset of the center point of a sensor, by using a part (of the rotational element) of the sensor and an offset detection device installed on the steering shaft.

Claims

[1] A device for detecting steering information, the device comprising: first to fourth torque sensors (410-440) configured to detect a relative rotation angle according to a distortion of a steering input shaft (100), a steering output shaft (200), and a torsion bar (300) disposed between the steering input shaft (100) and the steering output shaft (200); first to fourth rotation angle sensors (510-540) configured to detect an absolute rotation angle of the steering input shaft (100) or steering output shaft (200);a first synchronization checker (610) configured to check synchronization states of output values ​​of the four torque sensors (410-440); a second synchronization checker (620) configured to check synchronization states of output values ​​of the four rotation angle sensors (510-540); a torque calculator (700) configured to calculate a torque value based on at least one of the output values ​​of the four torque sensors (410-440) according to test results of the first and second synchronization checkers (610, 620); and a steering angle calculator (800) configured to calculate a steering angle based on at least one of the output values ​​of the four torque sensors (410-440) and at least one of the output values ​​of the four rotation angle sensors (510-540) according to test results of the first and second synchronization checkers (610, 620). [2] The apparatus according to claim 1, wherein the torque calculator (700) calculates the torque value applied to the torsion bar (300) using information on relative rotation angles of two or more torque sensors (410-440) whose synchronization states are determined to be a normal state by the first synchronization checker (610). [3] The apparatus according to claim 1, wherein the steering angle calculator (800) calculates the steering angle based on information about relative rotation angles output from one or more torque sensors (410-440) whose synchronization states are determined to be a normal state by the first synchronization checker (610) and information about absolute rotation angles output from the one or more rotation angle sensors (510-540) whose synchronization states are determined to be a normal state by the second synchronization checker (620). [4] The apparatus according to claim 1, wherein the four torque sensors (410-440) are classified into a plurality of torque sensor groups, the torque calculator (700) calculates the torque value applied to the torsion bar (300) using information about relative rotation angles of torque sensors (410-440) in a torque sensor group selected after determining by the first synchronization checker (610) that synchronization states of the torque sensors (410-440) are in a normal state, and all synchronization states of one or more torque sensors (410-440) included in the selected torque sensor group are determined to be in the normal state. [5] The apparatus of claim 1, wherein each of the torque sensors (410-440) comprises: an A-sensor configured to detect a rotational amount of the steering input shaft (100); and a B-sensor configured to detect a rotational amount of the steering output shaft (200), and wherein the first synchronization checker (610) determines that an i-th torque sensor (410-440) (i = 1, 2, 3 and 4) and a j-th torque sensor (j = 1, 2, 3 and 4; i≠j) are synchronized only when a difference between an output value of an A or B sensor of the i-th torque sensor (410-440) (i = 1, 2, 3 and 4) and an output value of an A or B sensor of the j-th torque sensor (410-440) (j = 1, 2, 3 and 4; i≠j) is less than or equal to a threshold value. [6] The apparatus according to claim 5, wherein the first synchronization checker (610) compares relative rotation angle information determined as a difference value between an output value of an A sensor and an output value of a B sensor of two or more synchronized rotation angle sensors (510-540) determined by comparing an output value of an A sensor and an output value of a B sensor, and determines a torque sensor (410-440) outputting different relative rotation angle information to be in a fault state. [7] The apparatus according to claim 5, wherein the torque calculator (700) determines a difference value between an output value of the A sensor and an output value of the B sensor of each of the two or more synchronized torque sensors (410-440) determined by the first synchronization checker (610) as a relative rotation angle of the corresponding torque sensor (410-440), and calculates the torque value based on an average value of the relative rotation angle information of the two or more torque sensors (410-440). [8] The apparatus according to claim 1, wherein the first synchronization checker (610) compares relative rotation angle information output from the first to fourth torque sensors (410-440) and determines a torque sensor outputting different relative rotation angle information as being in a fault state. [9] The apparatus according to claim 8, wherein the torque calculator (700) calculates the torque value from an average of the output values ​​of two torque sensors (410-440) having predetermined high priority ranks among torque sensors (410-440) in a normal state when two or more torque sensors (410-440) are determined to be in the normal state, and calculates the torque value based on an output value from one torque sensor (410-440) in a normal state when three torque sensors (410-440) are determined to be in the fault state. [10] The apparatus according to claim 9, wherein the steering angle calculator (800) calculates the steering angle based on an output value from a rotation angle sensor (510-540) having a highest priority rank among synchronized rotation angle sensors (510-540) and the average value of the output values ​​of the two torque sensors (410-440) in the normal state having the predetermined high priority ranks or the output value of the single torque sensor (410-440) in the normal state. [11] The apparatus of claim 8, wherein the torque calculator (700) calculates the torque value from an average of outputs of one or more torque sensors (410-440) determined to be in the normal state. [12] The device of claim 1, further comprising: Rotating elements (120, 130, 220) attached to one end of the steering input shaft (100) and one end of the steering output shaft (200) and adapted to rotate with the steering input shaft (100) and steering output shaft (200); Interference elements formed to protrude from peripheral surfaces of the steering input shaft (100) and steering output shaft (200); and a displacement sensor (1120) installed on at least one of the rotation elements (120, 130, 220) and configured to detect movement of the interference elements. [13] The apparatus of claim 12, wherein the displacement sensor (1120) is a photoelectric sensor that produces output signals that are variable according to the relative movement of the interference element and detects deviation of the rotary elements from an initial installation position on the steering input shaft (100) and steering output shaft (200). [14] A device for detecting steering information, the device comprising: a torque sensor (410-440) configured to detect a relative rotation angle according to distortion of a torsion bar (300) arranged between a steering input shaft (100) and a steering output shaft (200); an offset detection device (1100) comprising an interference element configured to protrude radially from a circumferential surface of the steering input shaft (100) or steering output shaft (200), and a displacement sensor (1120) installed on a rotation element (120, 130, 220) fixed to one end of the steering input shaft (100) or steering output shaft (200) and configured to generate an output signal according to movement with respect to the interference element; and a torque calculator (700) configured to calculate a torque applied to the torsion bar (300) from the relative rotation angle output by the torque sensor (410-440). [15] The apparatus of claim 14, wherein the displacement sensor (1120) is a photoelectric sensor that produces output signals that are variable according to the relative movement of the interference element, and wherein the displacement detecting device (1100) detects deviation of the rotary element (120, 130, 220) from an initial installation position on the steering input shaft (100) or steering output shaft (200). [16] A method for detecting steering information, the method comprising: Outputting information on relative rotation angles by first to fourth torque sensors (410-440) according to distortion of a torsion bar (300) arranged between a steering input shaft (100) and a steering output shaft (200) (S1310); Outputting information about absolute rotation angles of the steering input shaft (100) or steering output shaft (200) by the first to fourth rotation angle sensors (510-540) (S1312); a first synchronization checking process (S1320) of checking synchronization states of output values ​​of the four torque sensors (410-440); a second synchronization checking process (S1322) of checking synchronization states of output values ​​of the four rotation angle sensors (510-540); a torque calculation process (S1360) of calculating a torque value based on at least one of the output values ​​of the four torque sensors (410-440) according to results of the first synchronization check process (S1320); and a steering angle calculation process (S1370) of calculating a steering angle based on at least one of the output values ​​of the four torque sensors (410-440) and at least one of the output values ​​of the four rotation angle sensors (510-540) according to results of the first and second synchronization check processes (S1322). [17] The method according to claim 16, further comprising detecting deviation of a rotation member (120, 130, 220) from an initial installation position on the steering input shaft (100) or steering output shaft (200) by means of an offset detecting device (1100) comprising an interference member projecting radially from a circumferential surface of the steering input shaft (100) or steering output shaft (200) and an offset sensor (1120) installed on the rotation member (120, 130, 220) fixed to one end of the steering input shaft (100) or steering output shaft (200), and generating an output signal according to movement with respect to the interference member.

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