STEERING CONTROL DEVICE AND STEERING CONTROL METHOD

Abstract

Steering control device (200) comprising: a control current calculation unit (210) that calculates an initial control current for a steering wheel based on acquired steering information; a resistance calculation unit (220) that calculates an internal resistance based on a detected internal temperature; a supply current estimation unit (230) that estimates a supply current of a battery (100) based on the internal resistance, the first control current and an input supply voltage of the battery (100); and a control current application unit (240) that compares the supply current with a preset reference current, changes the first control current into a second control current by reducing it by a decrement if the supply current is greater than the reference current, and applies the second control current to a steering motor (500); wherein the second control current is a current reduced by a predetermined value compared to the first control current.

Description

Technical field

[0001] The disclosure relates to a steering control device and a steering control method. In particular, the disclosure relates to a technique that prevents overheating of a steering device by limiting the current supplied by a battery. State of the art

[0002] To assist in the steering of a moving vehicle, technology related to steering assistance devices, such as electronic power steering (EPS), is rapidly evolving.

[0003] EPS calculates the control current for driving the motor using information about the steering angle or the torque generated by turning the steering wheel, and steers the wheels via the motor's power, which is generated by applying the control current to the motor.

[0004] In particular, as the motor's power output increases, the control current supplied to the motor should also increase. To supply the motor with a higher control current, the current supplied by the battery also increases.

[0005] However, if the current supplied by the battery continues to increase, the components or devices contained in the EPS may overheat and consequently be damaged.

[0006] The publication US 2013 / 0342148A1 relates to the suppression of degradation processes in a motor and a motor driver circuit and describes a steering control device. Further prior art relevant to understanding the technological background of the present invention can be found in publications DE 37 89 033 T2, DE 60 2005 003 753 T2, DE 689 02 524 T2, DE 10 2005 006 643 A1, JP 2008-296 696 A and KR 10 2015 0 033 081 A. DETAILED DESCRIPTION OF THE INVENTION Technical Task

[0007] In light of the background, the disclosure provides a steering control device and a steering control method that utilize energy efficiently by preventing an oversupply of power from the battery. Technical solution

[0008] To address the aforementioned problems, according to one aspect of the disclosure, a steering control device according to claim 1 is provided, comprising a control current calculation unit that calculates a first control current for a steering wheel based on detected steering information, a resistance calculation unit that calculates an internal resistance based on a detected internal temperature, a supply current estimation unit that estimates a supply current of a battery based on the internal resistance, the first control current, and an input supply voltage of the battery, and a control current application unit that compares the supply current with a preset reference current, changes the first control current into a second control current by reducing it by a decrement if the supply current is greater than the reference current, and applies the second control current to a steering motor.where the second control current is a current reduced by a predetermined value compared to the first control current.

[0009] According to another aspect of the disclosure, a steering control method according to the other independent claim is provided, comprising a control current calculation step that calculates a first control current for a steering wheel based on detected steering information, a resistance calculation step that calculates an internal resistance based on a detected internal temperature, a supply current estimation step that estimates a supply current of a battery based on the internal resistance, the first control current and an input supply voltage of the battery, and a control current application step that compares the supply current with a preset reference current, changes the first control current into a second control current by reducing it by a decrement if the supply current is greater than the reference current, and applies the second control current to a steering motor.wherein the second control current is a current reduced by a predetermined value compared to the first control current. Advantageous embodiments are the subject of the dependent claims. Beneficial effects

[0010] As described above, according to the disclosure, a steering control device and a steering control method can be provided that utilize energy efficiently by preventing an oversupply of power from the battery. Brief description of the drawings Fig. Figure 1 is a block diagram showing a steering control system according to the disclosure; Fig. Figure 2 is a block diagram showing a steering control device according to the disclosure; Fig. 3 is a flowchart that represents a steering control procedure; Fig. Figure 4 is a flowchart showing a comparative example of changing a control stream; Fig. 5 is a flowchart showing an embodiment of the modification of a control stream according to the disclosure; Fig. 6 is a flowchart showing another embodiment of changing a control stream according to the disclosure; Fig. Figure 7 is a diagram that schematically illustrates a relationship between the rotational speed of a steering motor and the current supplied by a battery for each control current according to the disclosure; and Fig. Figure 8 is a diagram that schematically represents a relationship between the rotational speed of a steering motor and the steering torque for each control current according to the disclosure. Best mode for implementing the invention

[0011] In the following description of examples or embodiments of the disclosure, reference is made to the accompanying drawings, which show specific examples or embodiments that can be implemented for illustrative purposes and in which the same reference numerals and symbols can be used to denote identical or similar components, even if they are shown in different accompanying drawings. Furthermore, in the following description of examples or embodiments of the disclosure, detailed descriptions of known functions and components included herein are omitted where it is determined that the description would rather obscure the subject matter in some embodiments of the disclosure.The expressions used herein, such as "contain," "exhibit," "include," "consist of," and "formed of," are generally intended to permit the addition of other components, unless the expressions are used with the phrase "only." As used herein, singular forms are intended to include plural forms unless the context clearly indicates otherwise.

[0012] Expressions such as “first second”, “A”, “B”, “(A)”, or “(B)” may be used herein to describe elements of revelation. None of these terms are used to define any importance, order, sequence, or number of elements, etc., but are used merely to distinguish the respective element from other elements.

[0013] When it is mentioned that a first element is "connected or coupled" to a second element, or that it "touches or overlaps," this should be interpreted to mean that the first element can be "directly connected or coupled" to the second element, or that it can "directly touch or overlap," but also that a third element can be "arranged" "between" the first and second elements, or that the first and second elements can be "connected or coupled" to each other via a fourth element, or that they can "touch or overlap," etc. Here, the second element can be at least one of two or more elements that are "connected or coupled" to each other, "contact or overlap," etc.

[0014] When time-related terms such as "after", "coming after", "next", "before" and the like are used to describe processes or actions of elements or configurations or sequences or steps of actuation, processing, manufacturing procedures, these terms may be used to describe processes or actions that are not consecutive or follow one another, as long as the term "direct" or "immediately" is not used in conjunction with them.

[0015] When any dimensions, relative sizes, etc., are mentioned, it should also be borne in mind that numerical values ​​for an element or characteristic, or corresponding information (e.g., degree, area, etc.), include a margin of error or tolerance that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if a relevant description is not specified. Furthermore, the term "could" can encompass all meanings of the term "may."

[0016] Fig. Figure 1 is a block diagram showing a steering control system 10 according to the disclosure.

[0017] As in Fig. As shown in Figure 1, the steering control system 10 according to the disclosure can comprise a battery 100, a steering control device 200, a steering angle sensor 300, a temperature sensor 400 and a steering motor 500.

[0018] The battery 100 provides a supply current and a supply voltage to each of the components to carry out the operation of the steering control system 10.

[0019] For example, battery 100 supplies a current and voltage to the steering control device 200.

[0020] The supply current and supply voltage are the current and voltage supplied by the battery and can be direct current (DC) values.

[0021] The steering control device 200 can output a control current to the steering motor 500 to provide steering assistance for the vehicle. When the driver operates a steering wheel (not shown), the steering control device 200 can calculate a control current for the steering wheel using the steering information generated by the driver and apply the calculated control current to the steering motor 500.

[0022] In this case, the control current can be a current supplied to the steering motor 500. The control current can be an alternating current (AC), and the AC control current can be represented as a root mean square (RMS) value or as an instantaneous value.

[0023] In addition, the steering control device can receive 200 feedback or feedback information about the performance of the steering motor 500.

[0024] The steering control device 200 can be implemented as an electronic control unit, such as an electronic control unit (ECU), and in this case the ECU can comprise a microcontroller unit (MCU), an inverter, and a printed circuit board (PCB). However, embodiments of the disclosure are not limited thereto.

[0025] The steering angle sensor 300 can detect a steering angle generated by the rotation of the steering wheel (not shown), generate an electrical signal indicating the steering angle information, and output the electrical signal to the steering control device 200.

[0026] The temperature sensor 400 can detect the internal temperature of each component in the steering control system 10 or the internal temperature of the steering control system 10, generate an electrical signal indicating the internal temperature, and output the electrical signal to the steering control device 200.

[0027] For example, the temperature sensor 400 detects the internal temperature of the steering control device 200 and transmits information about the internal temperature to the steering control device 200.

[0028] The internal temperatures can be divided into the internal temperature of the steering control device 200 and the internal temperature of the steering motor 500. In this case, the internal temperature of the steering motor 500 can be estimated based on the internal temperature of the steering control device 200 detected by the temperature sensor 400.

[0029] For example, the internal temperature of the steering motor 500 can be estimated by interacting with changes in the internal temperature of the steering control device 200 at a predetermined ratio. For instance, if the internal temperature of the steering control device 200 increases by one degree, the internal temperature of the steering motor 500 can be estimated to increase by 0.5 degrees or 2 degrees. The interaction ratio between the internal temperature of the steering control device 200 and the internal temperature of the steering motor 500 can be preset to an experimentally determined value. When determining the interaction ratio, the temperature coefficients, the distance, and the temperature change rate of the components comprising the steering control device 200 and the steering motor 500 can be taken into account.In other words, since the interaction ratio between the internal temperature of the steering control device 200 and the internal temperature of the steering motor 500 is preset to an experimentally calculated value, the properties of the steering control system can be reproduced.

[0030] Although the term "internal temperature" is used generally throughout this disclosure for the sake of simplicity and clarity, it can refer to the internal temperature of the steering control device 200 or the internal temperature of the steering motor 500, as described above. In other words, when calculating the internal resistance based on the internal temperature and subsequently calculating a control current according to the disclosure below, only the steering control device 200 or only the steering motor 500 can be considered. Alternatively, the internal resistances of both the steering control device 200 and the steering motor 500 can be calculated individually and included in the calculation of the control current according to a predetermined ratio or degree of influence.

[0031] The steering motor 500 can receive a control current from the steering control device 200 and be driven to generate power corresponding to that control current. The power of the steering motor 500 can be the steering torque, the rotational speed, or a combination thereof.

[0032] The steering motor 500, for example, receives a control current and is driven in such a way that it generates a steering torque and a corresponding rotational speed corresponding to the control current.

[0033] Although not shown, a rack is moved linearly by the drive of the steering motor 500, and a steering knuckle and the wheels connected to the rack are also steered by the linear movement of the rack.

[0034] Although not shown, the steering control system 10 according to the disclosure can include a yaw rate sensor, a first torque sensor that detects the reaction torque of a reaction force motor, a second torque sensor that detects the steering torque of the steering motor, and a rotational speed sensor that detects the rotational speed of the steering motor.

[0035] The steering control device 200, which is included in the steering control system 10 according to the disclosure, is described in detail below.

[0036] Fig. Figure 2 is a block diagram showing a steering control device 200 according to the disclosure.

[0037] Referring to Fig. 2 The steering control device 200 according to the disclosure can comprise a control current calculation unit 210, a resistance calculation unit 220, a supply current estimation unit 230 and a control current application unit 240.

[0038] The control current calculation unit 210 can calculate an initial control current for the steering wheel based on the captured steering information.

[0039] The steering information for the steering wheel can refer to information about the steering angle and the torque generated by the driver when operating the steering wheel.

[0040] The first control current can be a current calculated by a preset algorithm using steering information for the steering wheel. Alternatively, the first control current can be a current supplied to the steering motor 500 when the battery 100 supply current meets a specific condition.

[0041] Referring to Fig. For example, the steering angle sensor 300 detects the steering angle generated by the steering wheel and transmits the steering angle information to the steering control device 200. The control current calculation unit 210 calculates the first control current based on the received steering wheel steering information.

[0042] The 220 resistance calculation unit can calculate the internal resistance based on the measured internal temperature. For example, if the internal temperature increases, the internal resistance may increase according to the device's characteristics. The increment can be determined using a preset lookup table or calculated using a preset formula.

[0043] The detected internal temperature can be the internal temperature of the steering control system 10 or the internal temperature of the steering control device 200, as described above. However, embodiments of the disclosure are not limited to these.

[0044] The internal resistance here can refer to the resistance of the steering control system 10 and the resistance of the steering control device 200. The resistance of the steering control system 10 can be understood to mean both the internal resistance of the steering control device 200 and the internal resistance of the steering motor 500, as described above.

[0045] For example, the temperature sensor 400 can be used with reference to Fig. 1. Detect the internal temperature of the steering control device 200 and input this information into the steering control device 200. The resistance calculation unit 220 can then calculate the internal resistance based on the internal temperature of the steering control device 200.

[0046] Meanwhile, the resistance calculation unit 220 can calculate the internal resistance by additionally using a reference temperature, a reference resistance, and a temperature coefficient corresponding to the reference temperature. If the internal resistance of the steering control device 200 and the internal resistance of the steering motor 500 are calculated individually, different reference resistances, temperature coefficients, and reference temperatures can be set.

[0047] Here, the reference temperature can be a standard temperature, e.g. 25 °C, and the reference resistance can be a resistance at the standard temperature (about 25 °C).

[0048] The temperature coefficient can be the temperature coefficient for a specific material. The temperature coefficient of copper, for example, is 3.9 [10 -3 / K].

[0049] In other words, the resistance calculation unit 220 can calculate the internal resistance R using the following equation 1. R=R0[1+α×(T−T0)]

[0050] Here, R0 is the reference resistance, α is the temperature coefficient, T is the detected internal temperature, and T0 is the reference temperature.

[0051] If the internal temperature changes in the meantime, the resistance calculation unit 220 can update the internal resistance according to the changed internal temperature.

[0052] The supply current estimation unit 230 can estimate the supply current of battery 100 based on the supply voltage of battery 100, the first control current, and the internal resistance. Specifically, the supply current estimation unit 230 can receive information for the first control current, calculated by the control current calculation unit 210, information for the internal resistance, calculated by the resistance calculation unit 230, and the supply voltage of battery 100, and estimate the supply current of battery 100, which is input to the steering control device 200, using the first control current, the supply voltage, and the internal resistance.

[0053] In this case, the supply current estimation unit 230 can estimate the supply current of the battery 100 based on the control current, which has been reduced by a predetermined value compared to the maximum value of the first control current, and not based on the first control current.

[0054] Meanwhile, the supply current estimation unit 230 can be fed back with the output or power of the steering motor 500 and estimate the supply current by taking the power of the steering motor 500 into account. In particular, the supply current estimation unit 230 can receive the feedback of the power of the steering motor 500 and then estimate the supply current (I Batt ) estimate using the following equation 2. IB​att=VBatt−VBatt−4R×(Poutput+R×IMotor2)2R

[0055] V is involved Batt The battery supply voltage is 100, R is the internal resistance, P output The power output of the steering motor is 500 and I Motor is the control current.

[0056] While the control current is being supplied to the steering motor 500, the control current applied to the steering motor 500 can be fed back to the supply current estimation unit 230. When the control current is fed back, the supply current estimation unit 230 can re-estimate the supply current by taking the fed-back control current into account.

[0057] The control current application unit 240 can compare the level of the supply current of the battery 100 with the level or strength of a preset reference current and change the level of the first control current according to the result of the comparison.

[0058] In particular, the control current application unit 240 can compare the supply current with the reference current and, if the supply current is greater than the reference current, change the first control current into a second control current and apply the second control current to the steering motor 500.

[0059] The reference current is a current that prevents the internal temperature of the steering control device 200 from rising too high and, like the supply current, can be a direct current (DC). Such a reference current can be determined through an experimental result, an algorithm, or similar means.

[0060] In this case, the second control current is a current that is reduced by a predetermined value from the maximum value of the first control current, and can be a current that is supplied to the steering motor 500.

[0061] In this case, if the first control current is changed to the second control current, the supply current estimation unit 230 can estimate the supply current by considering the second control current instead of the first control current.

[0062] Meanwhile, the control current application unit 240 can supply not only the control current but also the control voltage to the steering motor 500.

[0063] The following describes in detail a steering control procedure using the steering control device 200 according to the disclosure.

[0064] Fig. Figure 3 is a flowchart illustrating a steering control procedure.

[0065] As in Fig. As shown in Figure 3, in a control current calculation step S310 a first control current is calculated based on steering information for the steering wheel, which is detected by the steering angle sensor 300.

[0066] For example, the control current calculation unit 210 calculates the first control current based on steering angle information for the steering angle of the steering wheel detected by the steering angle sensor 300.

[0067] Subsequently, in a resistance calculation step S320, the internal resistance is calculated based on the internal temperature detected by the temperature sensor 400.

[0068] For example, the resistance calculation unit 220 first sets a reference temperature and a reference resistance corresponding to the reference temperature and calculates the internal resistance based on a difference value between the internal temperature and the reference temperature and the reference resistance.

[0069] In another example, the resistance calculation unit 220 determines a correction value by taking into account a preset temperature coefficient and a difference value between the internal temperature and the reference temperature for the reference resistance, and calculates the internal resistance by adding the correction value to the reference resistance.

[0070] Step S330 for estimating the supply current estimates the supply current of battery 100 based on the supply voltage of battery 100, the control current and the internal resistance.

[0071] For example, the supply current estimation unit 230 receives information about the internal resistance and supply voltage of battery 100, is fed back with the power of the steering motor 500, and receives the calculated first control current or is fed back with the first or second control current applied to the steering motor 500. Furthermore, the supply current estimation unit 230 estimates the supply current based on the internal resistance and supply voltage of battery 100, as well as the power and control current of the steering motor 500.

[0072] In a control current application step S340, the supply current is compared with a preset reference current and, depending on the comparison result, the first control current is supplied to the steering motor 500 or the first control current is converted into a second control current and the second control current is supplied to the steering motor 500.

[0073] For example, the control current application unit 240 supplies the first control current to the steering motor 500 when the supply current is equal to or less than the reference current.

[0074] As another example, if the supply current is greater than the reference current, the control current application unit 240 supplies the second control current to the steering motor 500.

[0075] The magnitude or strength of the second control current can be smaller than the magnitude of the first control current. As a special example, if the control current is represented as an RMS value, the RMS value of the second control current is smaller than the RMS value of the first control current. If the control current is represented as an instantaneous value, the maximum (or peak) value of the second control current is smaller than the maximum value of the first control current.

[0076] As described above, the steering control device 200 can, according to the disclosure, prevent the internal temperature of the steering control device 200 from rising excessively by limiting the current of the battery 100 to a certain level.

[0077] Meanwhile, it is necessary to switch to a suitable control current value depending on the estimated supply current and supply it to the steering motor 500 so that the steering control device 200 can efficiently control the steering motor 500 and at the same time prevent an excessive increase in the internal temperature.

[0078] The following are examples of how to change the control current according to the estimated supply current, as described in detail in accordance with the disclosure.

[0079] Fig. Figure 4 is a flowchart showing a comparative example of changing a control stream.

[0080] Referring to Fig. In step S410, an internal temperature information for the internal temperature of the steering control device 200 is received, and in step S420, the internal resistance is calculated using the received internal temperature information.

[0081] For example, the resistance calculation unit 220 first sets a reference resistance, a reference temperature and a temperature coefficient, receives the internal temperature information generated by the temperature sensor 400 and calculates the internal resistance by applying the reference resistance, the reference temperature, the temperature coefficient and the internal temperature to equation 1.

[0082] In step S430, the supply current of battery 100 is estimated based on the internal resistance and the supply voltage of battery 100.

[0083] For example, the supply current estimation unit 230 receives the supply voltage of the battery 100 as well as the power and control current of the steering motor 500 and estimates the supply current based on the internal resistance, the supply voltage of the battery 100 and the power and control current of the steering motor 500.

[0084] As another example, the supply current estimation unit 230 estimates the supply current of the battery 100 by inserting the internal resistance, the supply voltage of the battery 100 and the power and first control current of the steering motor 500 into equation 2.

[0085] In step S440, the magnitude of the estimated supply current is compared with the magnitude of a preset reference current.

[0086] If the magnitude of the supply current is equal to or less than the magnitude of the reference current, the calculated control current in step S460 is supplied unchanged to the steering motor 500. For example, the control current application unit 240 supplies the first control current to the steering motor 500 when the supply current is equal to or less than the reference current.

[0087] If the supply current is greater than the reference current, the control current is changed in step S450, and in the next step S460, the changed control current is applied to the steering motor 500. For example, if the supply current is greater than the reference current, the control current application unit 240 changes the first control current to the second control current so that the maximum value of the second control current is less than the maximum value of the first control current. Next, the control current application unit 240 supplies the second control current to the steering motor 500.

[0088] As described above, the steering control device 200 can predict whether the supply current of the battery 100 is being supplied in excess, reduce the control current and apply it to the steering motor 500, thereby preventing overheating.

[0089] Fig. Figure 5 is a flowchart showing an embodiment of the modification of a control stream according to the disclosure.

[0090] In Fig. Steps S510 to S540 are the same as those above. Fig. The sections described in point 4 are therefore skipped.

[0091] If the magnitude of the supply current is equal to or less than the magnitude of the reference current, the calculated control current in step S580 is given unchanged to the steering motor 500.

[0092] If the magnitude of the supply current is greater than the magnitude of the reference current, the maximum value of the first control current in step S550 is reduced. For example, the control current application unit 240 subtracts a preset deduction from the maximum value of the calculated first control current. Furthermore, the control current application unit 240 can recognize the control current obtained by subtracting the aforementioned deduction from the maximum value of the first control current as the second control current.

[0093] Then, in step S560, the supply current of battery 100, taking into account the reduced first control current, is re-estimated. For example, if, in a case where the second control current is a current reduced by a certain value compared to the maximum value of the first control current, the first control current is changed to the second control current, the power supply estimation unit 230 re-estimates the supply current by taking the second control current into account.

[0094] In step S570, the newly estimated supply current and the reference current are compared again. If the newly estimated supply current is still greater than the reference current, the reduced maximum value of the first control current is further reduced (S550), and the supply current is re-estimated taking the further reduced first control current into account (S560). The newly estimated supply current and the reference current are then compared (S570).

[0095] In other words, a first process to reduce the maximum value of the first supply current until the supply current is equal to or less than the reference current, and a second process to re-compare the newly estimated supply current with the reference current are repeatedly performed.

[0096] For example, if the supply current is greater than the reference current, the control current application unit 240 repeats the first process to reduce the maximum value of the first control current by a preset value and the second process to re-compare the reference current with the supply current re-estimated on the basis of the reduced control current, until the supply current is equal to or less than the reference current.

[0097] If the newly estimated supply current is equal to or less than the reference current, a second control current corresponding to the newly estimated supply current is applied to the steering motor 500 in step S580.

[0098] For example, if the newly estimated supply current is equal to or less than the reference current, the control current application unit 240 supplies the second control current, which corresponds to the newly estimated supply current, to the steering motor 500.

[0099] As described above, the steering control device 200 according to the invention can prevent the control current ultimately applied to the steering motor 500 from being reduced too much.

[0100] Fig. Figure 6 is a flowchart showing another embodiment of changing a control stream according to the disclosure.

[0101] In Fig. Steps S610 to S640 are the same as those above. Fig. The sections described in point 4 are therefore skipped.

[0102] If the magnitude of the supply current is greater than the magnitude of the reference current, a difference between the supply current and the reference current is calculated in step S650. Specifically, in step S650, a value is calculated that results from subtracting the magnitude of the reference current from the magnitude of the supply current.

[0103] To then extract a decrement to be subtracted from the maximum value of the first control current, a decrement corresponding to the difference calculated in step S650 is extracted in step S660 using a preset and stored lookup table.

[0104] Here, the lookup table can be a table summarizing the reduction in control current as a function of the differences between the supply currents and the reference currents. The lookup table may have been previously generated, for example, by an algorithm or an experiment.

[0105] In step S670, the maximum value of the first control current is reduced. In other words, in step S670, the extracted decrement is subtracted from the maximum value of the first control current.

[0106] For example, if the supply current is greater than the reference current, the control current application unit 240 calculates a difference between the supply current and the reference current, extracts the decrement corresponding to the difference based on the preset lookup table, and switches to the second control current, which has been reduced by the extracted decrement from the maximum value of the first control current.

[0107] Then, in step S680, the second control current is applied to the steering motor 500.

[0108] Although not shown, it can be, as in Fig. As shown in Figure 5, the supply current can be re-estimated by taking into account the reduced first control current after step S670.

[0109] As described above, the steering control device 200 according to the disclosure can adjust the control current more efficiently and quickly using a pre-made lookup table.

[0110] The following diagrams show the relationship between the steering torque and the speed of the steering motor 500 or the supply current of the battery 100 for the speed of the steering motor 500 when the control current is set according to the disclosure.

[0111] Fig. Figure 7 is a diagram that schematically represents a relationship between the rotational speed of a steering motor 500 and the current supplied by a battery 100 for each control current according to the disclosure.

[0112] Referring to Fig. 7. It can be observed that in a case where a specific control current is applied to the steering motor 500, an increase in the speed of the steering motor 500 typically also results in an increase in the supply current of the battery 100. In other words, a larger supply current is required to achieve a higher speed of the steering motor 500.

[0113] If, however, the rotational speed of the steering motor 500 remains constant, the supply current to the battery 100 increases with the maximum value of the control current supplied to the steering motor 500. In other words, if the maximum value of the control current increases, a larger supply current is required.

[0114] Accordingly, from a first diagram ① to a fifth diagram ⑤, the diagram corresponding to the largest maximum value of the control current is the first diagram ①, and the diagram corresponding to the smallest maximum value of the control current is the fifth diagram ⑤.

[0115] In a case where the steering control device 200 applies the control current to the steering motor 500 according to the first diagram ①, if the rotational speed of the steering motor 500 is increased by the steering control device 200, the required supply current of the battery 100 also increases according to the first diagram ①.

[0116] If, in this case, the supply current of the battery 100 is greater than the reference current R, the internal temperature of the steering control device 200 may be excessively increased and the steering control device 200 may be damaged as a result.

[0117] Therefore, if the supply current of the battery 100 is expected to gradually increase to a first point P1 as the rotational speed of the steering motor 500 increases, the steering control device 200 reduces the maximum value of the control current according to the disclosure. In other words, the steering control device 200 according to the disclosure supplies the control current according to the second curve ② instead of the control current according to the first curve ①.

[0118] Similarly, in a case where the steering control device 200 according to the disclosure applies the control current according to the second diagram ② to the steering motor 500, when the supply current of the battery 100 is expected to gradually increase to a second point P2, the steering control device 200 according to the disclosure supplies the control current according to the third diagram ③ instead of the control current according to the second diagram ②.

[0119] The first diagram ① to the fifth diagram ⑤ are only examples to facilitate the description, and there can preferably be a large number of diagrams.

[0120] Fig. Figure 8 is a diagram that schematically represents a relationship between the rotational speed of a steering motor and the steering torque for each control current according to the disclosure.

[0121] Referring to Fig. 8 is similar Fig. 7 from a first diagram ① to a fifth diagram ⑤ the diagram corresponding to the largest maximum value of the control current, the first diagram ①, and the diagram corresponding to the smallest maximum value of the control current, the fifth diagram ⑤.

[0122] In a case where the steering control device 200 according to the disclosure applies the control current according to the first diagram ① to the steering motor 500, when the rotational speed or rotational speed of the steering motor 500 increases and reaches a first point P1, the steering control device 200 according to the disclosure supplies the control current according to the second diagram ② instead of the control current according to the first diagram ①.

[0123] Similarly, when the rotational speed of the steering motor 500 increases and reaches a second point P2, the steering control device 200, according to the disclosure, provides the control current according to the third diagram ③ instead of the second diagram ②.

[0124] As described above, even if the steering torque of the steering motor 500 decreases slightly with increasing rotational speed of the steering motor 500, the disclosure can prevent damage to the steering control device 200 and ensure a stable steering assistance force.

[0125] As described above, according to the disclosure, a steering control device and a steering control method can be provided that utilize energy efficiently by preventing an oversupply of power from the battery.

[0126] Furthermore, according to the disclosure, a steering control device and a steering control method can be provided which can prevent damage to the control device due to overheating and provide driving stability to the driver.

[0127] Furthermore, according to the disclosure, a steering control device and a steering control method can be provided which can deliver a stable steering support or steering assistance force by minimizing the reduction of the steering torque.

[0128] The above description has been presented to enable any person skilled in the art to implement and utilize the technical idea of ​​the disclosure and has been given in connection with a specific application and its requirements. Various modifications, additions, and substitutions to the described embodiments will be readily apparent to a person skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the intent and scope of the disclosure. The above description and the accompanying drawings provide an example of the technical idea of ​​the disclosure only for illustrative purposes. That is to say, the disclosed embodiments are intended to illustrate the scope of the technical idea of ​​this disclosure.Therefore, the scope of this disclosure is not limited to the illustrated embodiments, but is to be granted the broadest scope in accordance with the claims. The scope of protection of the disclosure should be understood on the basis of the following claims, and all technical ideas that are equivalent to them should be considered to be within the scope of the disclosure. 10 Steering control system 100 batteries 200 Steering control device 210 Control current calculation unit 220 resistance calculation unit 230 Supply current estimating unit 240 Control current application unit 300 steering angle sensor 400 temperature sensor 500 steering motor

Claims

[1] Steering control device (200) comprising: a control current calculation unit (210) that calculates an initial control current for a steering wheel based on acquired steering information; a resistance calculation unit (220) that calculates an internal resistance based on a detected internal temperature; a supply current estimation unit (230) that estimates a supply current of a battery (100) based on the internal resistance, the first control current and an input supply voltage of the battery (100); and a control current application unit (240) that compares the supply current with a preset reference current, changes the first control current into a second control current by reducing it by a decrement if the supply current is greater than the reference current, and applies the second control current to a steering motor (500); wherein the second control current is a current reduced by a predetermined value compared to the first control current. [2] Steering control device according to claim 1, characterized by , that the resistance calculation unit (220) first sets a reference temperature and a reference resistance corresponding to the reference temperature and calculates the internal resistance using the reference resistance and a difference between the internal temperature and the reference temperature. [3] Steering control device according to claim 2, characterized by, that the resistance calculation unit (220) determines a correction value by taking into account the difference and a preset temperature coefficient at the reference resistance and calculates the internal resistance by adding the correction value to the reference resistance. [4] Steering control device according to claim 2, characterized by , that the internal temperature is divided into an internal temperature of the steering control device (200) and an internal temperature of the steering motor (500), and wherein the internal resistance is divided into a resistance of an element forming the steering control device (200) and a resistance of a winding of the steering motor (500). [5] Steering control device according to claim 4, characterized by, that the reference temperature and reference resistance for the steering control device (200) and the steering motor (500) are each set separately, and wherein the internal temperature of the steering motor (500) is estimated on the basis of the internal temperature of the steering control device (200). [6] Steering control device according to claim 1, characterized by that the internal resistance increases with increasing internal temperature. [7] Steering control device according to claim 1, characterized by , that the supply current estimation unit (230) is fed back to a power of the steering motor (500) and estimates the supply current by taking into account the power of the steering motor (500). [8] Steering control device according to claim 1, characterized by , that when the first control current is changed to the second control current, the supply current estimation unit (230) re-estimates the supply current by considering the second control current instead of the first control current. [9] Steering control device according to claim 1, characterized by , that the control current application unit (240) performs a first process to reduce a maximum value of the first control current by a preset decrement and repeats a second process to re-compare a newly estimated supply current based on the reduced control current with the reference current if the supply current is greater than the reference current, and if the newly estimated supply current is equal to or less than the reference current, applies a second control current to the steering motor corresponding to the newly estimated supply current. [10] Steering control device according to claim 1, characterized by , that the control current application unit (240) the difference between the supply current and the reference current is calculated when the supply current is greater than the reference current, a decrement corresponding to the difference based on a preset lookup table is extracted and to the second control stream, which is reduced by the extracted decrement from a maximum value of the first control stream. [11] Steering control device according to claim 1, characterized by , that the control current application unit (240) applies the first control current to the steering motor (500) when the supply current is equal to or less than the reference current. [12] Steering control procedures, including: a control current calculation step that calculates an initial control current for a steering wheel based on captured steering information; a resistance calculation step that calculates an internal resistance based on a detected internal temperature; a supply current estimation step that estimates a supply current of a battery (100) based on the internal resistance, the first control current and an input supply voltage of the battery (100); and a control current application step that compares the supply current with a preset reference current, changes the first control current into a second control current by reducing it by a decrement if the supply current is greater than the reference current, and applies the second control current to a steering motor (500); wherein the second control current is a current reduced by a predetermined value compared to the first control current. [13] Steering control method according to claim 12, characterized by, that the resistance calculation step first sets a reference temperature and a reference resistance corresponding to the reference temperature and calculates the internal resistance using the reference resistance and a difference between the internal temperature and the reference temperature. [14] Steering control method according to claim 13, characterized by , that the resistance calculation step determines a correction value by taking into account the difference and a preset temperature coefficient on the reference resistance and calculates the internal resistance by adding the correction value to the reference resistance. [15] Steering control method according to claim 13, characterized by, that the internal temperature is divided into an internal temperature of the steering control device (200) and an internal temperature of the steering motor (500), and wherein the internal resistance is divided into a resistance of an element forming the steering control device (200) and a resistance of a winding of the steering motor (500). [16] Steering control method according to claim 15, characterized by , that the reference temperature and reference resistance for the steering control device (200) and the steering motor (500) are each set separately, and wherein the internal temperature of the steering motor (500) is estimated on the basis of the internal temperature of the steering control device (200). [17] Steering control method according to claim 12, characterized by , that the supply current estimation step is fed back with a power of the steering motor (500) and estimates the supply current by taking into account the power of the steering motor (500). [18] Steering control method according to claim 12, characterized by , that the control current application step repeats a first process to reduce a maximum value of the first control current by a preset decrement and a second process to re-compare a supply current newly estimated on the basis of the reduced control current with the reference current if the supply current is greater than the reference current, and If the newly estimated supply current is equal to or less than the reference current, a second control current is applied to the steering motor (500) which corresponds to the newly estimated supply current. [19] Steering control method according to claim 12, characterized by , that the step of applying the control current the difference between the supply current and the reference current is calculated when the supply current is greater than the reference current, a decrement corresponding to the difference is extracted from a preset lookup table and to the second control stream, which is reduced by the extracted decrement from a maximum value of the first control stream. [20] Steering control method according to claim 12, characterized by , that the control current application step applies the first control current to the steering motor (500) when the supply current is equal to or less than the reference current.

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