KR101205560B1 - Method for Confirming Center Tap of Current Sensor by Using Window Comparator and Electronic Control Unit Therefor - Google Patents

Abstract

The present invention relates to a method for checking a midpoint of a current sensor using a window comparator and an electronic control apparatus therefor.

The present invention provides an electronic control unit (ECU) for detecting a generated torque from a torque sensor to control a motor, comprising: an inverter for transmitting a supply current to the motor; A current sensor which senses and delivers the supply current; A window comparator that receives a midpoint voltage from the current sensor, outputs a high signal if the midpoint voltage is within an error range, and outputs a low signal if the midpoint voltage exceeds an error range; And receiving the generated torque from the torque sensor, calculating a control current according to the generated torque to control the inverter to supply the supply current, and receiving the high signal or the low signal from the window comparator. When a high signal is input, the operation of the current sensor is determined as a fail, and when the low signal is input, the motor control unit (MCU: Motor Control Unit, hereinafter ' It provides an electronic control device that checks the center of the current sensor using a window comparator characterized in that it comprises a).

According to the present invention, by using the window comparator instead of the A / D converter to monitor the control current of the motor in the EPS ECU, the motor control current monitoring circuit without changing the MCU without affecting other logic or fail-safe There is an effect that can be configured.

EPS, MCU, Control, Current, Midpoint

Description

Method for Confirming Center Tap of Current Sensor by Using Window Comparator and Electronic Control Unit Therefor}

1 is a block diagram schematically illustrating an electronic control apparatus for checking a midpoint of a current sensor using a window comparator according to a preferred embodiment of the present invention;

2 is a circuit diagram schematically showing a window comparator according to a preferred embodiment of the present invention.

Description of the Related Art

110: torque sensor 120: ECU

130: MCU 140: Inverter

150: current sensor 160: window comparator

170: motor

The present invention relates to a method for checking a midpoint of a current sensor using a window comparator and an electronic control apparatus therefor. More specifically, a window comparator in the EPS ECU outputs a high signal when the current detection voltage is within the error range of the center voltage, and outputs a low signal when it is outside the error range of the center voltage. Method for checking the current sensor's center point using a window comparator which determines that the control current of the DC motor is normal when the high signal is received from the controller, and determines that there is an error in the control current of the DC motor when the low signal is received. It relates to a control device.

Normally, a hydraulic power steering device (Hydraulic Power Steering Apparatus) using the hydraulic pressure of a hydraulic pump is used as a steering device of an automobile, but since the 1990s, an electric power steering device (EPS: Electronic Power Steering Apparatus) has gradually become more common. have. Conventional hydraulic power steering system uses a hydraulic pump, which is the power source to assist the power, is driven by the engine and consumes energy all the time regardless of whether the steering wheel is rotated, whereas the electric steering system generates torque when the steering wheel rotates. A motor driven by electrical energy provides steering assistance power. Therefore, when the electric steering device is used, energy efficiency can be improved compared to the hydraulic power steering device.

In general, the electric steering device uses the generated torque, vehicle speed, steering angle, etc. to grasp the driver's steering intention and the driving condition of the vehicle, and generates steering assistance by comprehensively considering the steering column, rack bar, rack and pinion, etc. This makes it easier for the driver to drive and makes the car run safer.

Electric steering is composed of many mechanical and electronic components, but the most important configuration is the ECU (Electronic Control Unit). ECU is the core device of the electric steering device that analyzes the electric signals transmitted from various external sensors to understand the driver's steering intention and the driving situation of the car, and controls the motor using various logics provided. .

In general, the ECU detects the current flowing in the motor to precisely control the motor, and uses the current sensor to determine the current flowing in the motor. That is, if the motor uses a three-phase power source, a current sensor is attached to two phases of three phases (for example, a phase, b phase, and c phase a and b phases) to measure and measure the current of each phase. The current of each phase is used to calculate the current of the other phase.

The current sensor represents a positive or negative output based on the midpoint depending on the direction of steering. In addition, the output of the current sensor always outputs the midpoint, not the positive or negative output, during the time when the ECU performs the initial operation check, i.e. when the control is not performed. Therefore, if a positive or negative output is displayed at the time when the ECU performs the initial operation check, and in this case, it may be determined that the operation of the current sensor is a fail.

In the related art, in order to determine whether the current sensor is failing, an A / D converter of a MCU (Motor Control Unit) is generally used. However, when the A / D converters were used in other parts, that is, different logic or high priority fail-safe, it was difficult to use them to determine whether the current sensor failed.

Therefore, conventionally, in order to use an A / D converter to determine whether a current sensor fails in an ECU, there is a problem in that the MCU has to be changed or another fail-safe must be abandoned.

In order to solve the above problems, the present invention, by using a window comparator in the PS ECU outputs a high signal when the current detection voltage is within the error range of the midpoint voltage, and outputs a low signal when out of the error range of the midpoint voltage When the MCU receives the high signal from the window comparator, the control current of the DC motor is judged to be normal, and when the low signal is received, the current sensor using the window comparator determines that the control current of the DC motor is abnormal. It is an object of the present invention to provide a verification method and an electronic control device therefor.

In order to achieve the above object, the present invention provides an electronic control unit (ECU) for controlling a motor by detecting a generated torque from a torque sensor, comprising: an inverter for transmitting a supply current to the motor; A current sensor which senses and delivers the supply current; A window comparator that receives a midpoint voltage from the current sensor, outputs a high signal if the midpoint voltage is within an error range, and outputs a low signal if the midpoint voltage exceeds an error range; And receiving the generated torque from the torque sensor, calculating a control current according to the generated torque to control the inverter to supply the supply current, and receiving the high signal or the low signal from the window comparator. When a high signal is input, the operation of the current sensor is determined as a fail, and when the low signal is input, the motor control unit (MCU: Motor Control Unit, hereinafter ' It provides an electronic control device that checks the center of the current sensor using a window comparator characterized in that it comprises a).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 1 is a block diagram schematically illustrating an electronic control unit (ECU) hereinafter referred to as an electronic control unit (ECU) for checking the midpoint of a current sensor using a window comparator according to a preferred embodiment of the present invention.

ECU 120 according to a preferred embodiment of the present invention is connected to various sensors such as the torque sensor 110 and the like to the motor 170, to analyze the electric signal input from the torque sensor 110, etc. By detecting the driving situation by the driver, and outputs a supply current for controlling the drive torque of the motor 170 to suit the driving situation.

Here, in FIG. 1, the ECU 120 is illustrated as only connected to the torque sensor 110, but may be actually connected to a plurality of sensors for detecting a driving situation such as a vehicle speed sensor and a steering angle sensor. The motor 170 generates and transmits auxiliary power for smooth steering according to the supply current transmitted from the ECU 120.

In addition, ECU 120 according to a preferred embodiment of the present invention is a motor control unit (MCU: motor control unit, hereinafter referred to as "MCU") 130, the inverter (Inverter) 140, the current sensor 150 and Window comparator 160.

The MCU 130 is connected to the torque sensor 110 to receive the electrical signal from the torque sensor 110 to determine the generated torque, calculate the control current according to the generated torque to control the inverter 140 by the inverter 140 To supply the supply current corresponding to the control current to the motor 170.

The MCU 130 according to the preferred embodiment of the present invention uses the window comparator 160 to check the midpoint of the current sensor 150 attached to the connection between the inverter 140 and the motor 170. That is, the MCU 130 receives a low signal or a high signal input from the window comparator 160, and when the low signal is input, the MCU 130 determines the current sensor 150 as a fail and high. If a signal is input, it is determined as Safe.

Here, the window comparator 160 operates only while the power is supplied to the ECU 120 and the initial operation is checked to determine whether the current sensor 150 is fail-safe.

In addition, the MCU 130 calculates a control current according to the generated torque to control the inverter 140, a microprocessor for performing the calculation, the software of the algorithm for calculating the control current according to the generated torque, and controls the inverter 140 Non-volatile memory, such as software of an algorithm for storing the key value of the current sensor 150 and the like, and a temporary process that occurs when the microprocessor executes various software stored in the non-volatile memory and calculates And a volatile memory such as random access memory (RAM) for storing data.

The inverter 140 converts a direct current into an alternating current and supplies power to the motor 170. The inverter 140 supplies a supply current to the motor 170 under the control of the MCU 130. That is, the inverter 140 controls the operation of the motor 170 by varying the supply current supplied to the motor 170 by switching the switching element provided according to the control current when the control current is transmitted from the MCU 130. . At this time, since the inverter 140 converts direct current into alternating current and supplies it to the motor 170, the inverter 140 supplies three-phase alternating current power to the motor 170.

The current sensor 150 is a current sensor attached to a connection between the inverter 140 and the motor 170 to detect a current value of each phase and feed back to the MCU 130 via the window comparator 160.

The window comparator 160 outputs a high signal when the midpoint voltage input from the current sensor 150 is within an error range of the midpoint voltage, and outputs a low signal when the midpoint voltage is out of the error range of the midpoint voltage to the MCU 130. It performs the function. For example, when the mid-point voltage input from the current sensor 150 is 2.5 V and the mid-range voltage error range is 2.4 to 2.6 V, a high signal is output, and when the mid-point voltage is outside the 2.4-2.6 V low signal. The MCU 130 may determine whether to fail-safe the current sensor 150 by outputting the signal.

Accordingly, the MCU 130 operates the window comparator 160 instead of using the A / D converter during the time of performing the initial operation check, that is, the time when the control is not performed, thereby inputting from the window comparator 160. The low or high signal is input to determine whether the operation of the current sensor 150 is fail or safe.

2 is a circuit diagram schematically showing a window comparator according to a preferred embodiment of the present invention.

The window comparator 160 according to the preferred embodiment of the present invention operates at a time when power is applied to the ECU 120 to perform an initial operation check to determine whether the midpoint voltage input from the current sensor 150 is within an error range. . That is, when the error range of the midpoint voltage is 2.4 to 2.6V, and the midpoint voltage input from the current sensor 150 is less than 2.4V and exceeds 2.6V, a low signal is output, and when the midpoint voltage is 2.4V or more and 2.6V or less By outputting the low signal, the MCU 130 determines that the control current of the motor 170 is normal when the high signal is input from the window comparator 160, and when the low signal is input, the control current of the motor 170 is abnormal. To judge that there is.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

As described above, according to the present invention, by using the window comparator instead of the A / D converter to monitor the control current of the motor in the EPS ECU, without changing the MCU without affecting other logic or fail-safe, The motor control current monitoring circuit can be configured.

Claims (2)

In the electronic control unit (ECU: Electronic Control Unit) for detecting the generated torque from the torque sensor to control the motor, An inverter transferring a supply current to the motor; A current sensor which senses and delivers the supply current; Power is supplied to the electronic control device and operates only while checking an initial operation, receives a midpoint voltage from the current sensor, outputs a high signal if the midpoint voltage is within an error range, and the midpoint voltage. A window comparator outputting a low signal when the error range is exceeded; And The window comparator receives the generated torque from the torque sensor, calculates a control current according to the generated torque to control the inverter to supply the supply current, and the window comparator only during an initial operation check execution time without motor control. In operation, the high signal or the low signal is inputted from the window comparator, and when the high signal is input, the operation of the current sensor is determined as a fail, and when the low signal is input, the operation of the current sensor is determined. Motor control unit judged to be safe (MCU: Motor Control Unit, hereinafter referred to as 'MCU') Electronic control device for controlling the motor by detecting the generated torque from the torque sensor comprising a. delete

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