KR20180127786A - Control system and method for over heat protection in Electric power steering device - Google Patents

Abstract

The present invention relates to a control system and a method for overheat protection in an electric power steering device to prevent overheat by restricting a current of a driving motor based on current characteristics consumed in an electric power steering device. According to an embodiment of the present invention, the control system for overheat protection in an electric power steering device comprises a motor, a motor driving unit, a current calculation unit, and an electronic control unit (ECU). The current calculation unit calculates a consumed current based on a motor driving model in which a plurality of current paths are set in accordance with operation of the motor driving unit, and calculates thermal capacity in accordance with the consumed current. The ECU restricts a driving current of the motor when the thermal capacity exceeds a predetermined threshold.

Description

Technical Field [0001] The present invention relates to a control system and method for overheating prevention of an electric power steering device,

The present invention relates to an electric power steering apparatus, and more particularly, to an overheat prevention control system and method for an electric power steering apparatus that can prevent overheating by limiting a current of a drive motor based on a current characteristic consumed in an electric power steering apparatus .

Generally, an electric power steering (EPS) device is equipped with a steering motor on a steering wheel shaft, and when the vehicle starts, a steering motor operates to operate the power steering. This allows the driver to manipulate the steering according to the speed of the vehicle, thereby making it possible to operate the steering lightly and swiftly.

The EPS device receives the vehicle state information of the steering torque, the vehicle speed, and the steering angle inputted through the torque sensor, and the ECU (Electronic Control Unit) receives the motor driving signal. When the driver increases the torque, the assisting current also increases because the motor is driven by the assist current according to the motor driving signal to assist the steering operation.

When the amount of current applied to the steering motor becomes equal to or larger than the allowable current, the EPS device is overloaded with a field effect transistor (hereinafter referred to as "FET") of the electronic controller that controls the operation of the steering motor and the steering motor , The steering motor and the electronic controller can be ruptured due to overheating. Overheat protection (OHP) logic is applied to protect the EPS device, and the temperature measured by the temperature sensor mounted on the ECU and the current applied to the steering motor are monitored. The temperature of the steering motor and the temperature of the FET of the electronic controller are estimated, thereby controlling the current applied to the steering motor.

However, current characteristics consumed by the heat in the motor are different according to the driving conditions of the motor such as the motor RPM (Revolution Per Minute). However, the overheat prevention logic according to the conventional technology controls the current through the entire motor to control the current, There is a problem that the overheat prevention control is impossible.

Japanese Patent Laid-Open No. 2007-060736 (March 8, 2007)

An object of the present invention is to provide an overheat prevention control system and method for an electric power steering apparatus capable of preventing overheating by limiting the current of a drive motor based on a current characteristic consumed in an electric power steering system To be a technical challenge.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

In order to accomplish the above object, an overheat prevention control system of an electric power steering apparatus according to an embodiment of the present invention includes a motor, a motor driver, a current calculator, and an ECU (Electronic Control Unit). The current calculation unit calculates a consumed current based on a motor drive unit model in which a plurality of current paths corresponding to the operation of the motor drive unit are set, and calculates a heat capacity according to the consumed current. The ECU limits the drive current of the motor when the heat capacity exceeds a predetermined threshold value.

The current calculating unit of the overheat preventing control system of the electric power steering apparatus according to the embodiment of the present invention calculates the consumed current consumed in the motor driving unit and the ECU during the critical time. The average of the consumed current during the critical time is calculated. And accumulates the amount of current change during the critical time. The heat capacity is calculated based on the accumulation of the current change amount.

The current calculation unit of the overheat prevention control system of the electric power steering apparatus according to the embodiment of the present invention calculates the consumed current of the ECU by reflecting the temperature of the ECU.

The current calculation unit of the overheat preventing control system of the electric power steering apparatus calculates the consumed current of the motor based on the motor current input from the current sensor disposed in the motor driving unit and the speed of the motor input from the motor position sensor.

The motor driving unit of the overheat preventing control system of the electric power steering apparatus includes a first switching device connected between a positive terminal of the battery and the front end of the motor, and a second switching device connected between the positive terminal of the battery and the rear end of the motor. A third switching element connected between a rear end of the motor and the current sensor, a fourth switching element connected between a front end of the motor and the current sensor, and a fourth switching element connected in parallel with the first switching element, A second diode disposed in parallel with the second switching device, a third diode disposed in parallel with the third switching device, and a fourth diode disposed in parallel with the fourth switching device, .

In the overheat prevention control system of the electric power steering apparatus, the model of the motor driving unit is such that the first switching element and the third switching element are turned on, and the second switching element and the fourth switching element are turned And the first current path via the first switching element, the motor, and the third switching element.

In the overheat prevention control system of the electric power steering apparatus, the model of the motor driving section is configured such that the first to fourth switching elements are turned off, and the second current path through the fourth diode, the motor and the second diode .

In the overheat prevention control system of the electric power steering apparatus, the model of the motor driving section is such that the first switching element and the second switching element are turned on, the third switching element and the fourth switching element are turned off, And a third current path via the first switching element, the motor, and the second switching element.

In the overheat prevention control system of the electric power steering apparatus, the model of the motor driving section is such that the third switching element and the fourth switching element are turned on, the first switching element and the second switching element are turned off, And a fourth current path via the third switching element, the motor, and the fourth switching element.

In the overheat preventing control system of the electric power steering apparatus, the model of the motor driving section is configured such that the second switching element and the fourth switching element are turned on, the first switching element and the third switching element are turned off, And a fifth current path via the second switching element, the motor, and the fourth switching element.

The overheat prevention control method for an electric power steering apparatus according to an embodiment of the present invention is a method for controlling overheating of an electric power steering apparatus including a motor, a motor driving unit, and an ECU (Electronic Control Unit) Calculating a consumed current of the motor driving unit and the ECU based on a motor driving unit model in which a plurality of current paths corresponding to the operation of the motor driving unit are set; Calculating a current consumption amount during a critical time period, accumulating a current variation amount during the critical time, calculating a heat capacity of a current based on the accumulation of the current variation amount, And limiting the drive current of the motor when the current value exceeds the predetermined value.

In addition, other features and advantages of the present invention may be newly understood through embodiments of the present invention.

The overheat prevention control system and method of the electric power steering apparatus according to the embodiment of the present invention calculates the consumed current and the heat capacity in consideration of the current path of the motor driving unit 130 and the temperature of the ECU 150, Thereby restricting (or controlling) the drive current of the motor, thereby preventing the electric power steering device from overheating.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

1 is a block diagram of an overheat prevention control system of an electric power steering apparatus according to an embodiment of the present invention.
2 is a view illustrating a motor driving unit of an electric power steering system according to an embodiment of the present invention.
3 is a view showing a current consumed at the front end of the DC link and the rear end of the DC link by driving the motor driving unit.
4 is a view showing a current path according to a switching method of a switching element (FET) of a motor driving unit.
5 is a view showing a method of preventing overheating of an electric power steering system.
6 is a diagram showing a method of calculating a consumption current of an ECU (Electronic Control Unit) using a motor drive unit model.
7 is a diagram showing accumulation of a current change amount.
8 is a diagram showing the current heat capacity.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when a part is referred to as "including " an element, it does not exclude other elements unless specifically stated otherwise.

If any part is referred to as being "on" another part, it may be directly on the other part or may be accompanied by another part therebetween. In contrast, when a section is referred to as being "directly above" another section, no other section is involved.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Terms indicating relative space such as "below "," above ", and the like may be used to more easily describe the relationship to other portions of a portion shown in the figures. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain portions that are described as being "below" other portions are described as being "above " other portions. Thus, an exemplary term "below" includes both up and down directions. The device can be rotated by 90 degrees or rotated at different angles, and terms indicating relative space are interpreted accordingly.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

The overheat prevention control system and method of the electric power steering apparatus according to the embodiment of the present invention calculates the amount of current consumed in the steering motor and the motor control unit and controls the current applied to the steering motor based on the calculated amount of current, Overheating can be prevented.

FIG. 1 is a block diagram of an overheat prevention control system for an electric power steering apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating a motor driving unit of an electric power steering system according to an embodiment of the present invention.

1 and 2, an overheat prevention control system 100 of an electric power steering apparatus according to an embodiment of the present invention includes a motor 120 driven by a current supplied from a battery 110, a motor driving unit 130 A torque sensor 160, a vehicle speed sensor 170, a steering angle sensor 180, and a motor position sensor 190. The current sensor 140 detects the steering angle,

The motor 120 is driven by a current supplied to the battery 110 to generate a steering assist force for driver's steering.

The motor driving unit 130 drives according to the motor driving signal and supplies the driving current to the motor 120. The motor driving unit 130 includes a first switching device Q1, a second switching device Q2, a third switching device Q3, a fourth switching device Q4, and a current sensor (shunt resistor).

The torque sensor 160 detects the torque of the steering and supplies the detected steering torque to the ECU 150. [ The vehicle speed sensor 170 detects the speed (vehicle speed) of the vehicle and supplies the detected vehicle speed to the ECU 150. [ The steering angle sensor 180 detects the steering angle of the steering and supplies the detected steering angle to the ECU 150. [

The current sensor (shunt resistor) disposed in the current driving unit 130 senses the driving current of the motor 120 and supplies it to the current calculating unit 140.

The motor position sensor 190 measures the rotational speed of the motor and supplies the measured rotational speed of the motor to the current calculating section 140 and the ECU 150. [

The overheat prevention control system 100 of the electric power steering apparatus includes a temperature sensor for detecting the temperature of the ECU 150 in order to reflect the temperature of the ECU 150 at the time of calculating the consumed current. The temperature sensor detects the temperature of the ECU 150 and provides the detected ECU temperature to the current calculating unit 140. [ The ECU 150 detects the temperature of the ECU 150 in order to accurately calculate the consumed current of the ECU 150 because the consumed current of the ECU 150 varies depending on the temperature of the ECU 150. [

The current calculator 140 calculates the current value of the motor based on the motor current input from the current sensor, the speed of the motor input from the motor position sensor 190, and the ECU temperature input from the temperature sensor, (Consumed current amount) consumed during the critical time (or a predetermined time) is calculated.

Here, the current calculating unit 140 calculates the amount of current consumed in the motor driving unit 130 and the ECU 150 for a critical time (or a predetermined time) based on a motor driving unit model (described with reference to FIGS. 3 and 4) Consumed current amount) is calculated, and an average of the consumed current during the critical time is calculated. Further, the current calculating unit 140 accumulates the amount of current change during the critical time, and calculates the heat capacity according to the consumed current. The current calculation unit 140 supplies the ECU 150 with the current limitation information including the calculated consumed current amount, the consumed current average value, the cumulative value of the current change amount, and the heat capacity based on the consumed current.

ECU 150 generates a motor drive signal for adjusting the operation of the steering based on the steering torque, the vehicle speed, the steering angle and the current limit information. And controls (or controls) the current supplied to the motor driving unit 130 according to the generated motor driving signal.

2, the first switching device Q1 of the motor driving unit 130 according to the embodiment of the present invention is connected to the positive terminal of the battery 110 and the positive terminal of the motor 120, Respectively. The second switching device Q2 of the motor driving unit 130 is connected between the positive terminal of the battery 110 and the rear terminal of the motor 120 (negative terminal). The third switching element Q3 of the motor driving unit 130 is connected between the rear end of the motor 120 and the shunt resistor. The fourth switching device Q4 of the motor driving unit 140 is connected between the front end of the motor 120 and the shunt resistor.

The first diode D1 is arranged in parallel with the first switching device Q1 and the first terminal (positive terminal) of the first diode D1 is connected to the front end of the motor 120. [ And the second terminal (negative terminal) of the first diode D1 is connected to the positive terminal of the battery 110. [

The second diode D2 is arranged in parallel with the second switching element Q2 and the first terminal (positive terminal) of the second diode D2 is connected to the rear end of the motor 120. [ And the second terminal (negative terminal) of the second diode D2 is connected to the positive terminal of the battery 110. [

The first terminal (positive terminal) of the third diode D3 is connected to the current sensor (shunt resistor) and the negative terminal of the battery 110, and the third diode D3 is disposed in parallel with the third switching device Q3. Respectively. The second terminal (negative terminal) of the third diode D3 is connected to the rear end of the motor 120. [

A fourth diode D4 is arranged in parallel with the fourth switching device Q4 and the first terminal (positive terminal) of the fourth diode D4 is connected to the negative terminal of the current sensor (shunt resistor) Respectively. The second terminal (negative terminal) of the fourth diode D3 is connected to the front end of the motor 120. [

Here, the first switching device Q1, the second switching device Q2, the third switching device Q3, and the fourth switching device Q4 may be implemented by a field effect transistor (FET), a MOSFET, or the like. The current flowing through the current sensor (shunt resistor) to the ground GND is amplified by an amplifier, and the analog signal amplified by the analog-to-digital converter (ADC) is converted into a digital signal and supplied to the ECU 150.

FIG. 3 is a view showing a current consumed at the front end of the DC link and the rear end of the DC link by driving the motor driving unit, and FIG. 4 is a view showing a current path according to the switching method of the switching element (FET) of the motor driving unit.

3 and 4, in order to prevent the electric power steering device from overheating, the consumed current of the steering device must be accurately estimated, and the driving current supplied to the motor must be controlled based on the estimation. Considering the consumption characteristics of the steering device, the DC motor consumes the largest motor current and the BLAC (brushless AC) motor consumes the greatest battery power.

When the BLAC motor is applied to the steering apparatus, the first switching device Q1 and the third switching device Q3 are turned on and the second switching device Q2 and the fourth switching device Q4 are turned on, The first current path via the first switching device Q1, the motor 120, and the third switching device Q3 is formed. A drive current is supplied from the battery 110 to the motor 120 by the first current path, and the motor 120 is driven. At this time, a driving current is supplied from the battery 110 to the front end of the motor 120 via the first switching device Q1, and the driving current is supplied from the battery 110 to the motor 120 via the third switching device Q3. A driving current is supplied to the rear end of the motor 120 to drive the motor 120.

In this case, heat is generated in the battery 110 corresponding to the front end of the DC link, and heat is generated in the motor driving unit 130 and the motor 120 corresponding to the rear end of the DC link, . In this way, the current calculation unit 140 estimates the heat generation amount in consideration of the first current path (current path shown in FIG. 3) formed when the motor 120 is driven. In accordance with the estimated heat generation amount, the ECU 150 limits or controls the drive current of the motor. As a result, the electric power steering device can be prevented from overheating.

However, the current path is changed according to the switching method of the switching elements Q1, Q2, Q3, and Q4 disposed in the motor driving unit 130, and various current paths must be considered in order to prevent overheating of the electric power steering apparatus.

In the overheat prevention control system and method of the electric power steering apparatus, the current calculation unit 140 calculates the output of the motor 120 in consideration of various current paths formed in the motor driving unit 130, The amount of current consumed is calculated. Then, the heat capacity is calculated based on the calculated motor output and the amount of current. The ECU 150 can prevent the electric power steering device from overheating by limiting (or controlling) the current applied to the motor 120 based on the calculated heat capacity.

As one example, the first current path shown in Fig. 3 and the second to fifth current paths shown in Figs. 4 (a) to 4 (d) are set as the motor drive portion model. The current calculation unit 140 calculates the heat capacity according to the motor drive unit model, and the ECU 150 limits (or controls) the current applied to the motor 120 based on the calculated heat capacity.

The first switching device Q1, the second switching device Q2, the third switching device Q3 and the fourth switching device Q4 are turned off as shown in Fig. 4 (a) . At this time, a second current path starting from the battery 110 and passing through the fourth diode D4, the motor 120, and the second diode D2 is formed. The current calculation unit 140 calculates the consumed current in consideration of the second current path, and estimates the amount of heat generation based on the calculated consumed current. The ECU 150 can limit or control the driving current of the motor in accordance with the estimated heat generation amount in consideration of the second current path. The overheat prevention control system 100 can prevent overheating of the electric power steering device.

The first switching device Q1 and the second switching device Q2 are turned on and the third switching device Q3 and the fourth switching device Q4 are turned on as shown in FIG. When turned off, a third current path is formed through the first switching device Q1, the motor 120, and the second switching device Q2. The current calculation unit 140 calculates the consumed current in consideration of the third current path, and estimates the amount of heat generation based on the calculated consumed current. The ECU 150 can limit or control the drive current of the motor in accordance with the estimated heat generation amount in consideration of the third current path. The overheat prevention control system 100 can prevent overheating of the electric power steering device.

The third switching device Q3 and the fourth switching device Q4 are turned on and the first switching device Q1 and the second switching device Q2 are turned on as shown in Fig. When turned off, a fourth current path is formed through the third switching device Q3, the motor 120, and the fourth switching device Q4. The current calculation unit 140 calculates the consumed current in consideration of the fourth current path, and estimates the amount of heat generation based on the calculated consumed current. The ECU 150 can limit or control the drive current of the motor in accordance with the estimated heat generation amount in consideration of the fourth current path. The overheat prevention control system 100 can prevent overheating of the electric power steering device.

The second switching element Q2 and the fourth switching element Q4 are turned on and the first switching element Q1 and the third switching element Q4 are turned on as shown in Figure 4 (d) When turned off, a fifth current path is formed through the second switching device Q2, the motor 120, and the fourth switching device Q4. The current calculation unit 140 calculates the consumed current in consideration of the fifth current path, and estimates the amount of heat generation based on the calculated consumed current. The ECU 150 can limit or control the driving current of the motor in accordance with the estimated heat generation amount in consideration of the fifth current path. The overheat prevention control system 100 can prevent overheating of the electric power steering device.

5 is a view showing a method of preventing overheating of an electric power steering system.

1 and 5, at the time of driving the motor 120 by the steering of the steering, the current calculating unit 140 calculates the current value of the motor current inputted from the current sensor and the rotational speed of the motor input from the motor position sensor 190 The current and speed of the current motor are checked (S110).

Next, the current calculating unit 140 calculates consumed currents of the motor driving unit 130 and the ECU 150 based on the motor driving unit model set in consideration of the first to fifth current paths (S120).

The on-off state information of the first to fourth switching devices Q1 to Q4 disposed in the motor driving unit 130 is provided to the current calculating unit 140 through the motor driving unit 130 or the ECU 150 do. The current calculation unit 140 calculates the consumption currents of the motor driving unit 130 and the ECU 150 based on the current paths formed in the driving of the current motor driving unit 130 among the first to fifth current paths.

6 is a diagram showing a method of calculating a consumption current of an ECU (Electronic Control Unit) using a motor drive unit model. An example of a method of calculating the consumed current will be described with reference to FIG.

The current calculation unit 140 calculates the output of the motor 120 in consideration of the first to fifth current paths formed in the motor driving unit 130 (S210). The current path is determined according to whether the first to fourth switching elements Q1 to Q4 are turned on or off according to the operation of the motor driving unit 130 and the output of the motor 120 is determined based on the determined current path .

Here, the output of the motor is calculated in consideration of the motor speed and the steering torque using the following equation (1). In consideration of the inductance, the motor resistance, the motor torque, the motor resistance, the motor speed, the FET resistance, the pattern resistance of the PCB substrate, and the relay resistance of each of the first to fifth current paths generated in the motor driver 130, Output.

The "R" value in Equation (1) is calculated using Equation (2) below.

The "T" value in Equation (1) is calculated using Equation (3) below.

Next, the temperature of the ECU is checked using the temperature sensor (S220). The temperature of the ECU is supplied to the current calculating section 130.

Subsequently, the current calculating section 140 calculates the loss output of the ECU 150 and the motor based on the output of the motor and the ECU temperature (S230).

The current calculator 140 calculates the consumed current of the motor driver 130 and the ECU 150 based on the current path formed in the driving of the current motor driver 130 among the first to fifth current paths ).

Referring again to FIG. 5, the current calculating unit 140 calculates a consumed current average for a critical time (or a predetermined time) based on the calculated consumed current (S130).

Next, as shown in FIG. 7, the current calculator 140 accumulates the amount of current change during the critical time (or a predetermined time) (S140).

Next, as shown in Fig. 8, the current calculating section 140 calculates the heat capacity of the current based on the accumulation of the current change amount (S150). The current calculation unit 140 supplies the results of calculation of the heat capacity to the ECU 150. [ The current calculation unit 140 supplies the ECU 150 with the current limitation information including the calculated consumed current amount, the consumed current average value, the cumulative value of the current change amount, and the heat capacity according to the consumed current.

The ECU 150 determines whether the heat capacity included in the inputted current limitation information exceeds a predetermined threshold (S160).

If it is determined in step S160 that the heat capacity does not exceed the preset threshold value, that is, if the heat capacity is equal to or less than the preset threshold value, the above-described steps S110 to S150 are performed.

If it is determined in step S160 that the heat capacity exceeds the predetermined threshold value, the ECU 150 restricts (or controls) the current supplied to the drive motor (S170).

As an example, the ECU 150 generates a motor drive signal for regulating the operation of steering when the heat capacity exceeds a predetermined threshold value. And controls (or controls) the current supplied to the motor driving unit 130 according to the generated motor driving signal.

Subsequently, the ECU 150 drives the motor 120 using the motor drive signal in accordance with the changed conditions in S110 to S160.

The overheat prevention control system and method of the electric power steering apparatus calculates the consumed current and the heat capacity in consideration of the current path of the motor drive section 130 and the temperature of the ECU 150, It is possible to prevent overheating of the electric power steering device.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. .

In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, these functions may be stored or transmitted as one or more instructions or code on a computer readable medium. Computer-readable media includes both communication media and computer storage media including any medium that facilitates transfer of a computer program from one place to another. The storage medium may be any available media that is accessible by a computer. By way of example, and not limitation, such computer-readable media can comprise any computer-readable medium, such as RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, And any other medium that can be used to store and be accessed by a computer. Also, any connection is properly referred to as a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using a wireless technology such as coaxial cable, fiber optic cable, twisted pair cable, digital subscriber line (DSL), or infrared, radio and ultra high frequency, Wireless technologies such as fiber optic cable, twisted pair, DSL, or infrared, radio and microwave are included in the definition of media. Disks and discs as used herein include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVD), floppy discs and Blu-ray discs, While discs reproduce data optically by means of a laser. Combinations of the above should also be included within the scope of computer readable media.

When embodiments are implemented as program code or code segments, the code segments may be stored as a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, As well as any combination thereof. A code segment may be coupled to another code segment or hardware circuit by conveying and / or receiving information, data, arguments, parameters or memory contents. Information, arguments, parameters, data, etc. may be communicated, sent, or transmitted using any suitable means including memory sharing, message passing, token passing, Additionally, in some aspects, steps and / or operations of a method or algorithm may be performed on one or more of the codes and / or instructions on a machine readable medium and / or computer readable medium that may be integrated into a computer program product As a combination or set of < / RTI >

In an implementation in software, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor and external to the processor, in which case the memory unit may be communicatively coupled to the processor by various means as is known.

In a hardware implementation, the processing units may be implemented as one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays Controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe all possible combinations of components or methods for purposes of describing the embodiments described, but those skilled in the art will recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term "comprises" is used in the detailed description or the claims, such terms are intended to be inclusive in a manner similar to "consisting" .

Furthermore, as used in this application, the terms "component," "module," "system," and the like are intended to encompass all types of computer- Entity. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable execution thread, a program, and / or a computer. By way of illustration, both the application running on the computing device and the computing device can be components. One or more components may reside within a process and / or thread of execution, and the components may be centralized on one computer and / or distributed between two or more computers. These components may also be executed from various computer readable media having various data structures stored thereon. The components may be associated with a signal having one or more data packets (e.g., data from a local system, data from another component of the distributed system and / or signals from other components interacting with other systems via a network such as the Internet) Lt; RTI ID = 0.0 > and / or < / RTI > remote processes.

100: Overheat prevention control system
110: Battery
120: motor
130:
140:
150: ECU (Electronic Control Unit)
160: Torque sensor
170: vehicle speed sensor
180: steering angle sensor
190: Motor position sensor

Claims (11)

An overheat prevention control system for an electric power steering apparatus including a motor and a motor driving unit,
A current calculating unit for calculating a consumed current based on a motor drive unit model in which a plurality of current paths according to the operation of the motor driving unit are set and calculating a heat capacity according to the consumed current; And
And an ECU (Electronic Control Unit) for limiting a driving current of the motor when the heat capacity exceeds a preset threshold value. The apparatus according to claim 1,
Calculating consumption currents consumed in the motor driving unit and the ECU during the critical time, calculating an average of consumed currents during the critical time, accumulating current variation amounts during the critical time, And the heat capacity of the electric power steering device is calculated. The apparatus according to claim 1,
And calculates the consumed current of the ECU by reflecting the temperature of the ECU. The apparatus as claimed in claim 3,
Wherein the controller calculates the consumption current of the motor based on the motor current input from the current sensor disposed in the motor driving unit and the speed of the motor input from the motor position sensor. The method according to claim 1,
The motor drive unit includes:
A first switching element connected between a positive terminal of the battery and a front end of the motor,
A second switching element connected between a positive terminal of the battery and a rear end of the motor,
A third switching element connected between a rear end of the motor and the current sensor,
A fourth switching element connected between the front end of the motor and the current sensor,
A first diode disposed in parallel with the first switching device,
A second diode disposed in parallel with the second switching device,
A third diode disposed in parallel with the third switching device,
And a fourth diode disposed in parallel with the fourth switching device. 6. The motor driving apparatus according to claim 5,
The first switching device and the third switching device are turned on and the second switching device and the fourth switching device are turned off so that the first switching device, 3 < / RTI > switching element of the electric power steering device. 6. The motor driving apparatus according to claim 5,
Wherein the first to fourth switching elements are turned off, and a second current path via the fourth diode, the motor, and the second diode. 6. The motor driving apparatus according to claim 5,
The first switching element and the second switching element are turned on and the third switching element and the fourth switching element are turned off so that the third switching element and the third switching element are turned on via the first switching element, An overheat protection control system for an electric power steering device including a current path. 6. The motor driving apparatus according to claim 5,
The third switching element and the fourth switching element are turned on, the first switching element and the second switching element are turned off, and the fourth switching element, the motor and the fourth switching element An overheat protection control system for an electric power steering device including a current path. 6. The motor driving apparatus according to claim 5,
The second switching element and the fourth switching element are turned on, the first switching element and the third switching element are turned off, and the fifth switching element, the motor, and the fourth switching element An overheat protection control system for an electric power steering device including a current path. A method for controlling overheating of an electric power steering apparatus including a motor, a motor driving unit, and an ECU (Electronic Control Unit)
Confirming the current of the motor and the speed of the motor;
Calculating consumption currents of the motor driving unit and the ECU based on a motor driving unit model in which a plurality of current paths according to the operation of the motor driving unit are set;
Calculating a consumed current average for a critical time based on the calculated consumed current;
Accumulating a current change amount during the critical time;
Calculating a heat capacity of the current based on the accumulation of the current change amount; And
And limiting the drive current of the motor when the calculated heat capacity exceeds a preset threshold value.

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