STEERING CONTROL DEVICE AND METHOD FOR CALCULATING AN ABSOLUTE STEERING ANGLE

Abstract

Steering control device (100) comprising: a receiver (110) receiving an ignition-off signal and an ignition-on signal and receiving relative steering angle information received from a relative steering angle sensor (220, 420, 630) that only measures a relative angle of a steering wheel (210, 510), a calculator (120) that calculates range information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the range information, and a controller (130) that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after the ignition off when the ignition off signal is received, and generates an ignition-off signal according to a result of the determination, wherein the controller (130) determines whether the area information corresponds to a predetermined specific area, and, if the area information does not correspond to the specific area, generates a steering wheel correction control signal for moving the steering wheel (210, 510) to the specific area, and, if a steering wheel correction is performed according to the steering wheel correction control signal, generates the ignition off signal to perform the ignition off.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a steering control apparatus and method, and more particularly to a technique for calculating an absolute steering angle using a relative steering angle sensor of a steering wheel. GENERAL STATE OF THE ART

[0002] In a steering system of a vehicle, an absolute steering angle of a steering wheel can be measured using a difference between steering angles measured by two relative steering angle sensors.

[0003] However, the steering angle sensor is expensive and accounts for a significant portion of the cost of the steering system.

[0004] Therefore, there is a need to develop a technique capable of calculating the absolute steering angle of the steering wheel even with a single relative steering angle sensor.

[0005] US 2015 / 0051794 A1 relates to a steering angle detection device for a vehicle that detects the absolute steering angle of a steering mechanism, and to an electric power steering system incorporating the steering angle detection device. DE 198 16 928 A1 relates to a vehicle behavior control system, such as a yaw rate control system, for controlling the behavior of a vehicle. DE 601 03 232 T2 discloses a motor vehicle steering angle detector for detecting the steering angle of a steering mechanism of a motor vehicle. DETAILED DESCRIPTION OF THE INVENTION TECHNICAL PROBLEM

[0006] The disclosure proposes a steering control apparatus and method capable of measuring an absolute steering angle using a relative steering angle sensor.

[0007] The disclosure proposes a steering control apparatus and method capable of checking and correcting the accuracy of the absolute steering angle measurement using other sensor information and collision detection information. TECHNICAL SOLUTION

[0008] In one aspect, the present embodiments may provide a steering control device including a receiver that receives an ignition-off signal and an ignition-on signal and receives relative steering angle information received from a relative steering angle sensor that measures only a relative angle of a steering wheel, a calculator that calculates range information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the range information, and a controller that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after ignition-off when the ignition-off signal is received, and generates an ignition-off signal according to a result of the determination, wherein the controller determineswhether the area information corresponds to a predetermined specific area, and, if the area information does not correspond to the specific area, generates a steering wheel correction control signal for moving the steering wheel to the specific area, and, if a steering wheel correction is performed according to the steering wheel correction control signal, generates the ignition-off signal to perform the ignition off.

[0009] In another aspect, the present embodiments can provide a steering control method including a signal receiving step that receives an ignition-off signal and an ignition-on signal, an information receiving step that receives relative steering angle information received from a relative steering angle sensor that measures only a relative angle of a steering wheel, an information calculating step that calculates range information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the range information, and a control signal generating step that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after ignition-off when the ignition-off signal is received, and generates an ignition-off signal according to a result of the determination.wherein the control signal generating step includes a steering wheel correction control signal generating step that determines whether the area information corresponds to a predetermined specific area, and if the area information does not correspond to the specific area, generates a steering wheel correction control signal for moving the steering wheel to the specific area, and wherein, if a steering wheel correction is performed according to the steering wheel correction control signal, it generates the ignition-off signal to perform the ignition off. BENEFICIAL EFFECTS

[0010] As described above, the disclosure may provide a steering control apparatus and method capable of measuring an absolute steering angle using a relative steering angle sensor.

[0011] The disclosure may also provide a steering control apparatus and method capable of checking and correcting the accuracy of the absolute steering angle measurement using other sensor information and collision detection information. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram illustrating a steering control apparatus according to the disclosure; Fig. 2 is a view illustrating an example of a configuration of a steering apparatus including a steering control apparatus according to an embodiment; Fig. 3 is a view illustrating the calculation of absolute steering angle information according to an embodiment; Fig. 4 is a view illustrating an example of generating a storage signal and storing area information according to an embodiment; Fig. 5 is a view illustrating an example of correcting a steering wheel position upon receiving an ignition off signal according to an embodiment; Fig. 6 is a view illustrating an example of aligning a steering wheel upon receiving an ignition-on signal according to an embodiment; Fig. 7 is a flowchart illustrating a steering control method according to an embodiment; Fig. 8 is a flowchart illustrating an information calculation step according to an embodiment; Fig. 9 is a flowchart illustrating a control signal generation step when an ignition-off signal is received, according to one embodiment; and Fig. 10 is a flowchart illustrating a control signal generating step when an ignition-on signal is received according to one embodiment. MODE FOR CARRYING OUT THE INVENTION

[0012] In the disclosure, the absolute steering angle, which is 0 degrees, is defined as the steering wheel neutral position, a left turning angle is defined as a negative number, and a right turning angle is defined as a positive number. The relative steering angle has a value ranging from 0 degrees to 360 degrees, and when the steering wheel is in the neutral position, the relative steering angle is defined as 180 degrees.

[0013] Fig. 1 is a block diagram illustrating a steering control apparatus 100 according to the disclosure.

[0014] With reference to Fig. 1, a steering control device 100 includes a receiver 110 that receives an ignition-off signal and an ignition-on signal and receives relative steering angle information received from a relative steering angle sensor that measures only a relative angle of a steering wheel, a calculator 120 that calculates range information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the range information, and a controller 130 that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after ignition-off when the ignition-off signal is received, and generates an ignition-off signal according to a result of the determination.

[0015] Receiver 110 can receive an ignition off signal and can receive relative steering angle information. Furthermore, receiver 110 can receive other sensor information and collision detection information.

[0016] The ignition off signal and the ignition on signal refer to signals generated by an ignition switch for igniting the vehicle's engine. If the ignition switch is off (OFF), an ignition off signal is generated, and if the ignition switch is on (ON), an ignition on signal is generated. However, the disclosure includes a configuration of performing an ignition off when an absolute steering angle calculation condition is met, instead of performing an ignition off only with the generation of an ignition off signal. The absolute steering angle calculation condition is described in detail below in connection with the embodiment of the controller 130.

[0017] The relative steering angle information is information about the relative steering angle of the steering wheel, measured using a relative steering angle sensor. The relative steering angle sensor can only detect the angle at which the steering wheel is rotated between 0 degrees and 360 degrees, which is within a range of one revolution, even if the steering wheel is positioned in a range that exceeds one revolution. The relative steering angle information via the steering wheel can include a measured value regarding the rotation angle of the steering wheel in a range of 0 degrees to 360 degrees, which are angles corresponding to one revolution.

[0018] For example, if the absolute steering angle is +390 degrees, the steering wheel has been turned 30 degrees further from the state of having made a right turn from the neutral position (+360 degrees). Consequently, the relative steering angle is 210 degrees, which is 30 degrees further to the right than 180 degrees, which is the neutral position. Therefore, only the information indicating that the relative steering angle is 210 degrees can be known from the relative steering angle sensor, and without information regarding the steering wheel's rotation range, the absolute steering angle cannot be known.

[0019] Other sensor information refers to information acquired by a sensor other than the relative steering angle sensor. The other sensor may include any sensor capable of calculating the range information or absolute steering angle information about the steering wheel based on information acquired by the sensor, and any information acquired by the sensor may be included in the other sensor information.

[0020] For example, since the rotation angle of the steering motor and the rotation angle of the steering wheel may have a certain correlation, information regarding the steering angle can be calculated using the rotation angle information received from the motor sensor. Furthermore, since the steering torque and the rotation angle of the steering wheel may have a certain correlation, information regarding the steering angle can be calculated based on the torque detection information received from the torque sensor.

[0021] The calculation of information regarding the angle of rotation is described in detail below in connection with an embodiment for the calculator 120.

[0022] The collision detection information refers to information acquired by a collision detection sensor that detects a collision of the vehicle. The collision detection sensor can operate even after the ignition is turned off. Accordingly, when the ignition is turned on, the receiver 110 can receive collision detection information regarding whether a collision is detected after the last ignition was turned off.

[0023] The controller 130 may generate a steering angle adjustment control signal based on the other sensor information and the collision detection information, and this is described in more detail below in connection with an embodiment for the controller 130 and an embodiment in connection with Fig. 6 described.

[0024] The computer 120 can calculate range information using the relative steering angle information and calculate absolute steering angle information based on the relative steering angle information and the range information. Furthermore, the computer 120 can calculate target steering angle information to move the steering wheel to a predetermined specific range when the range information does not correspond to the specific range. If the other sensor information is received by the receiver 110, the computer 120 can calculate the range detection information based on the other sensor information.

[0025] The range information refers to information regarding the steering wheel's rotation range. The steering wheel's rotation range refers to a predetermined range divided from the total angular range in which the steering wheel is rotatable, with respect to the absolute steering angle. The range in which the steering wheel is currently positioned can be known by measuring the relative steering angle if the range in which the steering wheel is initially positioned is known. In other words, since it can be known whether the steering wheel is moving between ranges by a variation in the measured value of the relative steering angle, the range information itself can be calculated using relative steering angle information alone.

[0026] For example, if the steering wheel is capable of a total of three revolutions and is rotatable within a range of 1080 degrees, it is assumed that the rotation range is defined as a first range in which the absolute steering angle is -540 degrees to -180 degrees, a second range in which the absolute steering angle is -180 degrees to +180 degrees, and a third range in which the absolute steering angle is +180 degrees to +540 degrees. In this case, in a case where the initial position of the steering wheel is in the second range and the neutral position of the relative steering angle is 180 degrees, if the relative steering angle increases to 360 degrees and then changes by 30 degrees, this is the case where the steering wheel turns to the right in the second range in which the initial position is beyond the second range and goes beyond it.Consequently, the calculator 120 can calculate the current area information about the steering wheel as the third area.

[0027] The absolute steering angle information refers to information regarding the absolute steering angle of the steering wheel and is a value that is continuously measured within the entire angular range in which the steering wheel can be rotated. Consequently, the absolute position of the steering wheel itself can be known using the absolute steering angle information alone.

[0028] Such absolute steering angle information can be calculated by calculating the difference between the signals received by two relative steering angle sensors using a Vernier algorithm, or it can also be calculated based on the range information of the steering wheel and the relative steering angle information. In other words, even if there is only one relative steering angle sensor, the absolute steering angle information can be calculated if the range information of the steering wheel can be known.

[0029] For example, in a case where the steering wheel is a product whose absolute steering angle is defined as a first range from -540 degrees to -180 degrees, a second range from -180 degrees to +180 degrees, and a third range from +180 degrees to +540 degrees, and the range information about the steering wheel has three ranges and the relative steering angle information is 210 degrees, +390 degrees, which is +180 degrees, which is the rightmost end of the second range, plus 210 degrees, which is the relative steering angle, can be calculated as the absolute steering angle information.

[0030] The target steering angle information refers to information for moving the steering wheel to a specific point within a specific range. The specific range in the target steering angle information can be any point included in the specific range. For example, the specific point can be set as the neutral point where the absolute steering angle is always 0 degrees, or can be set as +180 degrees if the absolute steering angle is +180 degrees or more, or as -180 degrees if the absolute steering angle is -180 degrees or less. Therefore, the specific point can be set in various ways.

[0031] In contrast, the target steering angle information may be calculated as a remainder except for a quotient when an absolute steering angle based on the absolute steering angle information is divided by a predetermined target steering angle reference value.

[0032] For example, in a case where the steering angle information is +210 degrees, the specific range is the second range in which the absolute steering angle ranges from -180 degrees to +180 degrees, and the target steering angle reference value is set to 180 degrees, the target steering angle information may be calculated as +30 degrees, which is the remainder after +210 is divided by 180, up to 1, which is the quotient. In such a case, since it can be known that the target steering angle information is always calculated within the second range of -180 degrees to +180 degrees and thus corresponds to the second range, the calculation condition for an absolute steering angle can be satisfied even after an ignition off.

[0033] The range detection information refers to information regarding the turning range in which the steering wheel is positioned and can be calculated based on the other sensor information.

[0034] For example, if the other sensor information includes steering motor rotation angle detection information received from the motor sensor, the absolute steering angle can be calculated using the correlation between the steering motor rotation angle and the steering wheel rotation angle. Or, if the other sensor information includes steering torque detection information received from the torque sensor, the absolute steering angle can be calculated using the correlation between the steering torque and the steering wheel rotation angle. Alternatively, any sensors other than the motor sensor and the torque sensor that are capable of calculating the absolute steering angle based on the detection information can be used.

[0035] Therefore, if the absolute steering angle is calculated using the other sensor information, the range detection information regarding the turning angle of the steering wheel can be calculated using the calculated absolute steering angle.

[0036] Thus, the computer 120 can calculate the absolute steering angle relative to the absolute position of the steering wheel based on the other sensor information and calculate the range detection information about the steering wheel based on the calculated absolute steering angle. However, the computer 120 can, without limitation, calculate the range detection information about the steering wheel directly from the other sensor information without calculating the absolute steering angle.

[0037] The controller 130 may determine whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after ignition off when the ignition off signal is received, and generate an ignition off signal according to a result of the determination.

[0038] Further, when an ignition off signal is received, the controller 130 may determine whether the area information corresponds to a predetermined specific area, and if it does not correspond to the specific area, generate a steering wheel correction control signal for moving the steering wheel to the specific area, and if a steering wheel correction is performed according to the steering wheel correction control signal, generate an ignition off signal to perform an ignition off.

[0039] If the steering wheel correction is performed according to the steering wheel correction control signal, the controller 130 may generate a steering wheel lock control signal to prevent the steering wheel from moving before the ignition off signal is generated. Furthermore, if an ignition on signal is received after the ignition off, the controller 130 may generate a steering wheel unlock control signal to unlock the steering wheel.

[0040] If the receiver 110 receives other sensor information or collision detection information and receives an ignition-on signal, the controller 130 may determine whether it is necessary to align the steering wheel based on the received information and generate a steering wheel alignment control signal for aligning the steering wheel to the neutral state according to a result of the determination.

[0041] The absolute steering angle calculation condition refers to a condition regarding whether it is possible to calculate the absolute steering angle information based on the relative steering angle information even after the ignition is turned off. The absolute steering angle can be calculated using, for example, a Vernier algorithm if there are two or more relative steering angle sensors. However, if there is only one relative steering angle sensor, range information regarding the steering wheel rotation angle should be known to calculate the absolute steering angle information. In other words, if there is only one relative steering angle sensor, the absolute steering angle calculation condition can be set as a condition under which range information about the steering wheel can be known even after the ignition is turned off.

[0042] To find out the area information, a separate memory signal may be generated, and the area information before the ignition is turned off may be stored to be used when the ignition is turned on, or a correction may be made so that the steering wheel is positioned in a predetermined specific area before the ignition is turned off, and when the ignition is turned on, the initial position of the steering wheel is within the specific area. In this regard, the configuration for generating the separate memory signal and storing the area information is described in detail below in connection with Fig. 4, and the configuration for correcting to allow the steering wheel to be positioned in the specific area is described in detail below in connection with Fig. 5 described.

[0043] The ignition off control signal refers to a control signal that enables an ignition off to actually be performed when the receiver 110 receives an ignition off signal.

[0044] If an ignition off is performed without satisfying the calculation condition for an absolute steering angle, the range information about the steering wheel cannot be known when the ignition is turned on later, and if the range information is not known, it is impossible to calculate the absolute steering angle information with only the relative steering angle information.

[0045] Accordingly, the controller 130 may generate an ignition off control signal to prevent the ignition from being turned off when the absolute steering angle calculation condition is not satisfied and to allow the ignition to be turned off when the absolute steering angle calculation condition is satisfied.

[0046] The steering wheel lock control signal refers to a control signal to prevent movement of the steering wheel, and the steering wheel unlock control signal refers to a control signal to unlock the steering wheel to allow movement of the steering wheel.

[0047] Even if the absolute steering angle calculation condition is met before ignition off, if steering wheel movement is permitted after ignition off, the steering wheel's rotation range will be changed, so the range information may be altered. Therefore, it is necessary to prevent steering wheel movement after ignition off to maintain the absolute steering angle calculation condition until the ignition is turned on.

[0048] Accordingly, even though the ignition off signal is received and the absolute steering angle calculation condition is satisfied, the controller 130 may generate a steering lock control signal to prevent movement of the steering wheel and thereafter generate an ignition off control signal instead of immediately generating an ignition off control signal.

[0049] Further, when an ignition-on signal is received, the controller 130 must unlock the locked steering wheel before the last ignition off to allow movement of the steering wheel to perform steering of the vehicle, and thus may allow a steering wheel unlock control signal to be generated.

[0050] The steering wheel correction control signal refers to a control signal for moving the steering wheel to a specific area when the area information does not correspond to the specific area.

[0051] If there is only one relative steering angle sensor, the calculation condition for an absolute steering angle can be set to whether the range information can be known even after the ignition is turned off. If the ignition is turned off in a state where the steering wheel is always within the specific range, the steering wheel will be within the specific range even when the ignition is turned on, so the range information can be known. Therefore, the calculation condition for an absolute steering angle can be met.

[0052] Therefore, when an ignition-off signal is received, controller 130 can determine whether the range information corresponds to the specific range and, if it does not correspond to the specific range, generate a steering wheel correction control signal to move the steering wheel to the specific range. Any technique related to steering wheel movement control can be applicable to the control for moving the steering wheel to the specific range.

[0053] Furthermore, since correction of the steering wheel is possible at any point included in the specific range, it is possible to generate a steering wheel correction control signal based on the target steering angle information calculated by the calculator 120.

[0054] Furthermore, when the steering wheel correction control signal is generated, the controller 130 may immediately control the steering wheel to move to the specific area, and the controller 130 may transmit a steering wheel alignment notification message to the user to instruct the user to move the steering wheel to the specific area. Or, the controller 130 may transmit a steering wheel alignment notification message to the user and, if the steering wheel is not moved to the specific area within a certain predetermined time, perform control to move the steering wheel to the specific area.

[0055] In summary, after allowing the steering wheel to be positioned according to the steering correction control signal and preventing the steering wheel from moving according to the steering lock control signal, if an ignition off is performed according to the ignition off control signal, the range information can be known because the steering wheel is positioned in the specific range even when the ignition is turned on. Accordingly, it is possible to calculate the absolute steering angle information based on the relative steering angle information detected by a relative steering angle sensor and the known range information after the ignition is turned on.

[0056] The steering wheel alignment control signal refers to a control signal for adjusting the actual position of the steering wheel to the position of the steering wheel determined based on the range information and the relative steering angle information if the range detection information calculated by the calculator 120 and the range information as a result of comparison differ when the ignition is turned on, or if a collision is detected based on the collision detection information received by the receiver 110 after the last ignition off.

[0057] Even if the calculation condition for an absolute steering angle before an ignition switch-off is satisfied so that absolute steering angle information can be calculated even with only a relative steering angle sensor, after the ignition switch-on, such an error as a mismatch between the actual position of the steering wheel and the position of the steering wheel determined based on the relative steering angle and the range information may occur.

[0058] For example, an error may occur because incorrect range information may be calculated or the neutral position of the steering wheel may be shifted, e.g., due to a failure or malfunction of the relative steering angle sensor. Furthermore, if the vehicle collides after the ignition is turned off, the range information may be changed, or the steering wheel may be moved, causing an error.

[0059] When such an error occurs, the steering wheel must be realigned to correctly calculate the absolute steering angle and range information after the ignition is turned on.

[0060] Accordingly, an ignition-on signal is received, and the controller 130 compares the range detection information calculated based on the other sensor information with the range information. If the comparison result reveals that the two pieces of information indicate different ranges, the controller may determine that an error has occurred and generate a steering wheel alignment control signal to realign the steering wheel. In contrast, the controller 130 may compare the absolute steering angle information calculated based on the other sensor information with the relative steering angle information. If the difference between the two values ​​is a predetermined reference value or more, the controller may determine that an error has occurred and generate a steering wheel alignment control signal.

[0061] Furthermore, if an ignition-on signal is received and a collision is detected after the last ignition-off based on the collision detection information received from the collision detection sensor, the controller 130 may determine that an error occurs between the position of the steering wheel determined based on the range information and the relative steering angle and the actual position of the steering wheel, and generate a steering wheel alignment control signal to realign the steering wheel.

[0062] To align the steering wheel, any known technique for comparing the actual position of the steering wheel with the measured value as well as techniques for aligning the steering wheel to the neutral state can be used.

[0063] In addition, if the range information and the absolute steering angle information calculated based on the relative steering angle information and the range detection information and the absolute steering angle calculated based on the other sensor information are compared and it is determined that an error occurs between the absolute steering angle information and the range information, the steering wheel may be allowed to be moved and aligned as described above, or the stored values ​​for the range information and the absolute steering angle information stored in the storage device may be modified to the absolute steering angle and the range information value calculated based on the other sensor information.

[0064] Fig. 2 is a view illustrating an example of a configuration of a steering apparatus including a steering control apparatus according to an embodiment.

[0065] With reference to Fig. 2, a steering device may include a steering control device 100, a steering wheel 210, a relative steering angle sensor 220, a motor sensor 230, and a torque sensor 240.

[0066] When an ignition-off signal is received, the steering control device 100 may generate an ignition-off control signal for performing ignition-off if the calculation condition for an absolute steering angle is satisfied, and, if the calculation condition for an absolute steering angle is not satisfied, generate and control a steering wheel correction control signal to move the steering wheel 210 to the specific area and thereafter generate an ignition-off control signal for performing ignition-off.

[0067] As described above, if an ignition off is performed in a state where the calculation condition for an absolute steering angle is satisfied, range information regarding the rotation range in which the steering wheel 210 is positioned when the ignition is turned on later can be known, so that it is possible to calculate the absolute steering angle information based on the known range information and the relative steering angle information even if there is only one relative steering angle sensor 220.

[0068] The steering control device 100 may calculate the absolute steering angle information using other sensor information received from another sensor including the motor sensor 230 and the torque sensor 240, and calculate the range detection information based on the calculated absolute steering angle.Then, if the compared ranges indicated by the range detection information and the range information are different from each other, or if the difference between the calculated absolute steering angle and the absolute steering angle information compared with each other is a reference value or more, the steering control device 100 may determine that an error has occurred and generate a steering wheel alignment control signal to move the steering wheel 210 to match the actual position of the steering wheel 210 with the position of the steering wheel 210 determined based on the range information and the relative steering angle information.

[0069] Fig. 3 is a view illustrating the calculation of absolute steering angle information according to an embodiment.

[0070] When there are two or more relative steering angle sensors, the absolute steering angle can be calculated using the phase difference between values ​​measured by the relative steering angle sensors. However, when there is only one relative steering angle sensor, it is impossible to calculate the absolute steering angle using only the relative steering angle information based on the single relative steering angle sensor.

[0071] However, if the range information about the steering wheel can be known when the ignition is turned on, even if the steering wheel is moved to another range, the range information after the movement can be calculated by continuously measuring the relative steering angle information, and the absolute steering angle information can be calculated based on the range information and the relative steering angle information.

[0072] As an example, a first graphical representation 300, which is shown in Fig. 3 represents the relative steering angle information measured according to changes in the rotation angle of the steering wheel when the steering wheel of the steering device is a product capable of making a total of three revolutions and being rotatable within a range of 1080 degrees. The rotation range of the steering wheel may be divided into a first range from 0 degrees to 360 degrees with respect to the first revolution, a second range from 0 degrees to 360 degrees with respect to the second revolution, and a third range from 0 degrees to 360 degrees with respect to the third revolution. In this case, the 180 degrees of the second range indicate the neutral point in the actual position of the steering wheel.

[0073] In this case, if the area information about the steering wheel can be known when the ignition is turned on, even if the steering wheel is moved to another area, the area information after the movement can be calculated based on the area information and the relative steering angle information.

[0074] For example, in a case where the area information about the steering wheel is the second area when the ignition is turned on, and the relative steering angle information is 330 degrees, if the relative steering angle later increases to 360 degrees and thereafter becomes 0 degrees and thereafter increases again and becomes 30 degrees, then the steering wheel is moved from the second area to another area, and the area information after the movement can be calculated as the third area.

[0075] A second graphic representation 350 of Fig. 3 illustrates the absolute steering angle information calculated based on the range information and the relative steering angle information about the same product as the steering device for the first graphical representation 300.

[0076] In this case, the absolute steering angle information for the second graphical representation 350 may be calculated based on the range information and the relative steering angle information for the first graphical representation 300.

[0077] For example, in a case where the range information about the steering wheel is the second range and the relative steering angle information is 330 degrees, the relative steering angle is a point moved 150 degrees to the right from the neutral point of the steering wheel positioned at 180 degrees of the second range, and thus the absolute steering angle can be calculated as +150 degrees. Alternatively, in a case where the range information about the steering wheel is the third range and the relative steering angle information is 330 degrees, the relative steering angle is a point moved 330 degrees further to the right from the starting point of the third range, which is moved 180 degrees to the right from the neutral point of the steering wheel, and thus the absolute steering angle can be calculated as +510 degrees.

[0078] Fig. 4 is a view illustrating an example of generating a storage signal and storing area information according to an embodiment.

[0079] With reference to Fig. 4, upon receiving an ignition-off signal, the steering control device 100 may generate a storage signal for storing range information that satisfies the calculation condition for an absolute steering angle. Thereafter, if the range information corresponding to the storage signal is stored, the steering control device 100 may generate an ignition-off control signal to perform ignition-off.

[0080] The area information may be stored in the storage device 410, and in this case, the storage device 410 may be configured as a non-volatile storage device in which the stored information does not disappear when the ignition is turned off.

[0081] In this case, when the ignition is turned on later, the rotation range where the steering wheel is positioned can be found using the range information stored in the storage device 410. Consequently, it is possible to continuously calculate the absolute steering angle information using the range information stored in the storage device 410 and the relative steering angle information detected by the relative steering angle sensor 420 after the ignition is turned on.

[0082] Fig. 5 is a view illustrating an example of correcting the position of a steering wheel 510 upon receiving an ignition off signal according to one embodiment.

[0083] With reference to Fig. 5, upon receiving an ignition-off signal, the steering control device 100 may determine whether the range information corresponds to a predetermined specific range to satisfy the absolute steering angle calculation condition, and if it does not correspond to the specific range, generate a steering wheel correction control signal for moving the steering wheel 510 to the specific range. Thereafter, if the correction of the steering wheel 510 is performed according to the steering wheel correction control signal, the steering control device 100 may generate an ignition-off control signal to perform ignition-off.

[0084] As an example illustrated Fig. 5 shows a case where the range information about the steering wheel 510 is the third range, the relative steering angle information is 30 degrees, the predetermined specific range is the second range including the neutral point of the steering wheel 510, and the target steering angle reference value is set to 180 degrees.

[0085] In this case, the steering control device 100 may calculate the absolute steering angle information as +210 degrees, which is 30 degrees to the right of +180 degrees, which is the starting point of the third range, based on the relative steering angle information being 30 degrees. Thereafter, since the range information about the steering wheel 510 does not correspond to the second range, which is the specific range, the steering control device 100 may generate a steering wheel correction control signal for moving the steering wheel to the second range.

[0086] The steering wheel correction control signal includes the content to control the steering wheel 510 to move according to the target steering angle information calculated as +30 degrees, which is the remainder after dividing +210 degrees, which is the absolute steering angle information, by the target steering angle reference value, ie, 180 degrees, up to the quotient.

[0087] Therefore, when the ignition-off signal is received, the steering control device 100 can calculate the target steering angle information and generate a steering wheel correction control signal to move the steering wheel 510 to the specific range according to the target steering angle information. After the correction of the steering wheel 510 is performed according to the steering wheel correction control signal, the steering control device 100 can generate a steering wheel lock control signal to prevent movement of the steering wheel, generate an ignition-off control signal, and control the ignition-off, with the absolute steering angle calculation condition satisfied.

[0088] Fig. 6 is a view illustrating an example of aligning a steering wheel upon receiving an ignition-on signal according to one embodiment.

[0089] With reference to Fig. 6, upon receiving an ignition-on signal, the steering control device 100 may generate a steering wheel alignment control signal for aligning the steering wheel when the area detection information and the area information differ from each other as a result of comparison or when a collision is detected after the last ignition-off based on the collision detection information.

[0090] As an example, with reference to Fig. 6, upon receiving an ignition-on signal, the steering control device 100 may calculate range detection information based on other sensor information received from the motor sensor 610 or the torque sensor 620, and calculate range information using the relative steering angle information received from the relative steering angle sensor 630. Thereafter, the steering control device 100 may compare the range detection information with the range information, and if the two pieces of information indicate different ranges, determine that an error has occurred between the position of the steering wheel calculated based on the range information and the relative steering angle information and the actual position of the steering wheel.The steering wheel needs to be realigned to calculate more accurately and eliminate the error between the absolute steering angle information and the range information.

[0091] Furthermore, with reference to Fig. 6, upon receiving an ignition-on signal, the steering control device 100 receives collision detection information from the collision detection sensor 640 to detect a vehicle collision. Based on the collision detection information received from the collision detection sensor 640, if a collision is detected after the last ignition-off, the steering wheel may be moved due to the collision, so an error may occur between the position of the steering wheel calculated based on the range information and the relative steering angle information and the actual position of the steering wheel. The steering wheel must be realigned to calculate more accurately and eliminate the error between the absolute steering angle information and the range information.

[0092] Therefore, when an ignition-on signal is received, the steering control device 100 can determine whether the range detection information and the range information differ from each other, or whether a collision is detected after the last ignition-off, thereby determining whether the steering wheel needs to be aligned. Then, if it is determined that the steering wheel needs to be aligned, the steering control device 100 can generate a steering wheel alignment control signal to compare the actual position of the steering wheel with the range information and the absolute steering angle information. To align the steering wheel, any known technique for comparing the actual position of the steering wheel with the measured value, as well as techniques for aligning the steering wheel to the neutral state, can be used.

[0093] The steering control device 100 will be described below again in light of a method, and what has been described above will be omitted as necessary but is also applicable to the method.

[0094] Fig. 7 is a flowchart illustrating a steering control method according to an embodiment.

[0095] With reference to Fig. 7, a steering control method may include an ignition signal receiving step S710 that receives an ignition off signal and an ignition on signal, an information receiving step S720 that receives relative steering angle information received from a relative steering angle sensor that measures only a relative steering angle of a steering wheel, an information calculating step S730 that calculates range information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the range information, and a control signal generating step S740 that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after ignition off when the ignition off signal is received, and generates an ignition off control signal according to a result of the determination.

[0096] The ignition signal receiving step S710 may receive an ignition off signal and an ignition on signal generated by an ignition switch to ignite the vehicle's engine. However, in the disclosure, an ignition off is performed by generating an ignition off signal when a calculation condition for an absolute steering angle is met, rather than immediately performing an ignition off with only the generation of an ignition off signal.

[0097] Information receiving step S720 may receive relative steering angle information measured using a relative steering angle sensor. Furthermore, information receiving step S720 may also receive other sensor information acquired by sensors other than the relative steering angle sensor, such as a motor sensor or a torque sensor, and collision detection information acquired by a collision sensor that detects a vehicle collision.

[0098] The information calculation step S730 may calculate range information using the relative steering angle information and calculate absolute steering angle information based on the relative steering angle information. Furthermore, the information calculation step S730 may calculate target steering angle information to move the steering wheel to a specific range when the range information does not correspond to the specific range, or calculate range detection information based on the other sensor information.

[0099] The control signal generation step S740 may determine whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after ignition off when the ignition off signal is received, and generate an ignition off control signal according to a result of the determination.

[0100] Further, the control signal generation step S740 may include a storage signal generation step for storing area information when an ignition-off signal is received, and generating an ignition-off control signal for performing ignition off when the area information corresponding to the storage signal is stored.

[0101] More various embodiments for the information calculation step S730 and the control signal generation step S740 when an ignition off signal or an ignition on signal is received will be described below with reference to the drawings.

[0102] Fig. 8 is a flowchart illustrating an information calculation step S730 according to an embodiment.

[0103] With reference to Fig. 8, the information calculation step S730 may include a range information calculation step S810 and an absolute steering angle information calculation step S820.

[0104] The range information calculation step S810 can calculate the range information itself with only the relative steering angle information because it is possible to know the inter-range movement of the steering wheel by a change in the measured value of the relative steering angle if the initial position of the steering wheel can be known.

[0105] The absolute steering angle information calculation step S820 may calculate the absolute steering angle information based on the range information and the relative steering angle information, since the absolute steering angle can be calculated if the range information about the position of the steering wheel and the relative steering angle can be known.

[0106] Fig. 9 is a flowchart illustrating a control signal generation step S740 when an ignition off signal is received according to one embodiment.

[0107] With reference to Fig. 9, when an ignition-off signal is received, the control signal generation step S740 may include a steering wheel correction control signal generation step S910, a steering wheel lock control signal generation step S920, and an ignition-off control signal generation step S930.

[0108] When the ignition off signal is received, the steering wheel correction control signal generation step S910 may determine whether the area information corresponds to a predetermined specific area and, if it does not correspond to the specific area, generate a steering wheel correction control signal for moving the steering wheel to the specific area.

[0109] If the steering wheel correction is performed according to the steering wheel correction control signal, the steering wheel is positioned in the specific range, and if an ignition off is performed with the steering wheel positioned in the specific range, range information about the steering wheel can be known when the ignition is later turned on, so that the calculation condition for an absolute steering angle can be satisfied.

[0110] The steering wheel correction control signal may include target steering angle information for moving the steering wheel to a specific point of the specific range, and the target steering angle information may be calculated as the remainder, except for the quotient, after dividing the absolute steering angle by a predetermined target steering angle reference value based on the absolute steering angle information.

[0111] The steering lock control signal generation step S920 may generate a steering lock control signal to prevent movement of the steering wheel. Even if the absolute steering angle calculation condition is satisfied before ignition off, if steering wheel movement is permitted after ignition off, the steering wheel rotation range is changed, so that the range information may be changed. Therefore, it is necessary to prevent movement of the steering wheel after ignition off so as to maintain satisfaction of the absolute steering angle calculation condition until the ignition is turned on later.

[0112] Accordingly, even though the ignition-off signal is received and the calculation condition for an absolute steering angle is satisfied, a steering lock control signal may be generated to prevent movement of the steering wheel and thereafter generate an ignition-off control signal instead of immediately generating an ignition-off control signal.

[0113] The ignition-off control signal generation step S930 can generate an ignition-off control signal to actually perform ignition-off. Since the range information about the steering wheel after ignition-off should be known in order to calculate the absolute steering angle information using the relative steering angle information, it is necessary to determine whether the absolute steering angle calculation condition is met when the ignition-off signal is received.

[0114] Accordingly, the ignition-off control signal generation step S930 may generate an ignition-off control signal to prevent the ignition from being turned off when the absolute steering angle calculation condition is not satisfied and to allow the ignition to be turned off when the absolute steering angle calculation condition is satisfied.

[0115] In Fig. 9, the steering lock control signal generation step S920 may be omitted. For example, when an ignition-off signal is received, the control signal generation step S740 may include only the steering wheel correction control signal generation step S910 and the ignition-off control signal generation step S930.

[0116] Fig. 10 is a flowchart illustrating a control signal generation step S740 when an ignition-on signal is received according to one embodiment.

[0117] With reference to Fig. 10, when an ignition-on signal is received, the control signal generation step S740 may include a steering wheel unlock control signal generation step S1010, a steering wheel orientation detection step S1020, and a steering wheel orientation control signal generation step S1030.

[0118] To perform vehicle steering after the ignition is turned on, the steering wheel, which was locked before the last ignition was turned off, must be unlocked to allow movement of the steering wheel. Consequently, the steering wheel unlock control signal generation step S1010 may generate a steering wheel unlock control signal to unlock the steering wheel to allow movement of the steering wheel if an ignition-on signal is received.

[0119] The steering unlock control signal generation step S1010 can only be performed if the control signal generation step S740, when an ignition off signal is received, in Fig. 9 includes the steering lock control signal generation step S920. In other words, if the steering lock control signal generation step S920 is omitted before an ignition off, the steering lock control signal generation step S1010 can be omitted from the control signal generation step S740 when an ignition on signal is received in Fig. 10 can be omitted.

[0120] The steering wheel alignment determination step S1020 compares the area information using the relative steering angle information and the area detection information based on the other sensor information when the ignition-on signal is received, and determines whether a collision is detected after the last ignition-off based on the collision detection information, thereby determining whether the steering wheel needs to be aligned.

[0121] Even if the calculation condition for an absolute steering angle before an ignition off is satisfied so that absolute steering angle information can be calculated even with only a relative steering angle sensor, such an error as a mismatch between the actual position of the steering wheel and the position of the steering wheel determined based on the relative steering angle and the range information may occur.

[0122] For example, an error may occur because incorrect range information may be calculated or the neutral position of the steering wheel may be shifted, e.g., due to a failure or malfunction of the relative steering angle sensor. Furthermore, if the vehicle collides after the ignition is turned off, the range information may be changed, or the steering wheel may be moved, causing an error.

[0123] Consequently, the steering wheel must be realigned to accurately calculate the absolute steering angle and range information after the ignition is turned on.

[0124] If, as a result of determining whether the steering wheel needs to be aligned, it is determined that alignment of the steering wheel is not required, the control signal generation step S740 is immediately terminated, but if it is determined that the steering wheel needs to be aligned, the steering wheel alignment control signal generation step S1030 is performed.

[0125] The steering wheel alignment control signal generation step S1030 may generate a steering wheel alignment control signal to compare the actual position of the steering wheel with the position of the steering wheel determined based on the range information and the relative steering angle information when the steering wheel alignment determination step S1020 determines that the steering wheel needs to be aligned because the range detection information and the range information differ as a result of a comparison or a collision is detected after an ignition off based on the collision detection information.

[0126] To align the steering wheel, any known technique for comparing the actual position of the steering wheel with the measured value as well as techniques for aligning the steering wheel to the neutral state can be used.

[0127] As described above, the disclosure may provide a steering control apparatus and method capable of measuring an absolute steering angle using a relative steering angle sensor.

[0128] The disclosure may also provide a steering control apparatus and method capable of checking and correcting the accuracy of the absolute steering angle measurement using other sensor information and collision detection information.

Claims

[1] Steering control device (100) comprising: a receiver (110) receiving an ignition-off signal and an ignition-on signal and receiving relative steering angle information received from a relative steering angle sensor (220, 420, 630) that only measures a relative angle of a steering wheel (210, 510), a calculator (120) that calculates range information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the range information, and a controller (130) that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after the ignition off when the ignition off signal is received, and generates an ignition-off signal according to a result of the determination, wherein the controller (130) determines whether the area information corresponds to a predetermined specific area, and, if the area information does not correspond to the specific area, generates a steering wheel correction control signal for moving the steering wheel (210, 510) to the specific area, and, if a steering wheel correction is performed according to the steering wheel correction control signal, generates the ignition off signal to perform the ignition off. [2] The steering control device (100) according to claim 1, wherein the controller (130) generates a memory signal for storing the area information and generates the ignition off signal to perform the ignition off when the area information is stored according to the memory signal. [3] The steering control device (100) according to claim 2, wherein the calculator (120) calculates the absolute steering angle information based on the stored range information corresponding to the memory signal and the relative steering angle information when the ignition-on signal is received. [4] Steering control device (100) according to claim 1, wherein the controller (130) a steering wheel lock control signal for preventing movement of the steering wheel (210, 510) is generated if the ignition off signal is received and the steering wheel correction is carried out according to the steering wheel correction control signal, and a steering wheel unlock control signal for releasing a locked state of the steering wheel (210, 510) is generated if the ignition-on signal is received. [5] The steering control device (100) according to claim 1, wherein the steering wheel correction control signal includes target steering angle information for moving the steering wheel (210, 510) to a specific point of the specific range, and wherein the target steering angle information is calculated as a remainder except for a quotient when an absolute steering angle based on the absolute steering angle information is divided by a predetermined target steering angle reference value. [6] The steering control device (100) according to claim 1, wherein the receiver (110) receives other sensor information including information regarding a measured value of a sensor other than the relative steering angle sensor (220, 420, 630) from the other sensor, wherein the computer (120) calculates area detection information regarding an area where the steering wheel (210, 510) is positioned using the other information and wherein, when the ignition-on signal is received, the controller (130) compares the range detection information with the range information to determine whether they are identical, and, if a result of the comparison shows that they are different, generates a steering wheel alignment control signal for aligning the steering wheel (210, 510) to a neutral state. [7] The steering control device (100) according to claim 1, wherein the receiver (110) receives collision detection information from a collision detection sensor (640) that detects a collision of a vehicle, and wherein, if the ignition-on signal is received, the controller (130) determines whether a collision is detected after the last ignition off based on the collision detection information, and, if the collision is detected, generates a steering wheel alignment control signal for aligning the steering wheel (210, 510) to a neutral state. [8] Steering control method comprising: a signal receiving step that receives an ignition off signal and an ignition on signal, an information receiving step that receives relative steering angle information, which are received by a relative steering angle sensor (220, 420, 630) which only measures a relative angle of a steering wheel (210, 510), an information calculation step that calculates area information using the relative steering angle information and calculates absolute steering angle information based on the relative steering angle information and the area information, and a control signal generation step that determines whether an absolute steering angle calculation condition for calculating the absolute steering angle information is satisfied even after the ignition off when the ignition off signal is received, and generates an ignition off signal according to a result of the determination, wherein the control signal generating step includes a steering wheel correction control signal generating step which determines whether the area information corresponds to a predetermined specific area and, if the area information does not correspond to the specific area, generates a steering wheel correction control signal for moving the steering wheel (210, 510) to the specific area and wherein, if a steering wheel correction is performed according to the steering wheel correction control signal, it generates the ignition off signal to perform the ignition off. [9] A steering control method according to claim 8, wherein the control signal generating step includes a storage signal generating step for storing the area information, and an ignition-off signal is generated to perform ignition off when the area information is stored according to the storage signal. [10] A steering control method according to claim 8, wherein the control signal generating step includes: a steering wheel lock control signal generating step that generates a steering wheel lock control signal for preventing movement of the steering wheel (210, 510) if the ignition off signal is received and the steering wheel correction is performed according to the steering wheel correction control signal, and a steering wheel unlock control signal generating step that generates a steering wheel unlock control signal for releasing a locked state of the steering wheel (210, 510), if the ignition on signal is received. [11] The steering control method according to claim 8, wherein the steering wheel correction control signal includes target steering angle information for moving the steering wheel (210, 510) to a specific point of the specific range, and wherein the target steering angle information is calculated as a remainder except for a quotient when an absolute steering angle based on the absolute steering angle information is divided by a predetermined target steering angle reference value. [12] A steering control method according to claim 8, wherein the information receiving step includes an other sensor information receiving step of receiving other sensor information including information regarding a measured value of a sensor other than the relative steering angle sensor (220, 420, 630) from the other sensor, wherein the information calculation step includes an area detection information calculation step that calculates area detection information regarding an area where the steering wheel (210, 510) is positioned using the other information, and wherein the control signal generating step includes a steering wheel alignment control signal generating step which, when the ignition-on signal is received, compares the area detection information with the area information to determine whether they are identical, and, if a result of the comparison shows that they are different, generates a steering wheel alignment control signal for aligning the steering wheel (210, 510) to a neutral state. [13] The steering control method according to claim 8, wherein the information receiving step includes a collision detection information receiving step that receives collision detection information from a collision detection sensor (640) that detects a collision of a vehicle, and wherein the control signal generating step includes a steering wheel alignment control signal generating step that, if the ignition-on signal is received, determines whether a collision is detected after the last ignition-off based on the collision detection information, and, if the collision is detected, generates a steering wheel alignment control signal for aligning the steering wheel (210, 510) to a neutral state.

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