KR20080078443A - Method for confirming center tap of current sensor by using torque sensor and electronic control unit therefor - Google Patents

Abstract

A method for detecting a center point of a current sensor by using a torque sensor and an electronic control unit therefore are provided to detect the operation of a current sensor to be safe or fail by forming an MCU. An electronic control unit comprises an inverter(140) transmitting a supply current to a motor(160), a current sensor(150) transmitting the supply current, and an MCU(Motor Control Unit)(130). The MCU receives the generation torque from a torque sensor(110), controls the inverter to supply the supply current by calculating a control current according to the generation torque, detects that the operation of the current sensor is fail if the output voltage of the current sensor is a positive or negative output with the output voltage of the torque sensor by comparing the output voltage from the current sensor with the output voltage of the torque sensor, and detects that the operation of the current sensor is safe if the output voltage of the current sensor has the same center point with the output voltage of the torque.

Description

Method for Confirming Center Tap of Current Sensor by Using Torque Sensor 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 torque sensor according to a preferred embodiment of the present invention;

2 is a graph confirming the midpoint of a current sensor using a torque sensor according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

110: torque sensor 120: ECU

130: MCU 140: Inverter

150: current sensor 160: motor

The present invention relates to a method for checking a midpoint of a current sensor using a torque sensor and an electronic control apparatus therefor. In more detail, the method of checking the current sensor's center point using a torque sensor that detects the current sensor's failure by detecting the output of the current sensor based on the output of the torque sensor at the initial operation time and the electronic control for the ECU Relates to a 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.

These current sensors represent positive or negative outputs 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 is abandoned.

In order to solve the above-mentioned problems, the present invention, the center of the current sensor using the torque sensor to detect the output of the current sensor based on the output of the torque sensor at the initial operating time in the ECU to determine whether the current sensor (Fail) 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; 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, receiving an output voltage from the current sensor, and outputting the output voltage of the torque sensor. In comparison with, if the output voltage of the current sensor is positive or negative output with the output voltage of the torque sensor, the operation of the current sensor is determined as a fail, and the If the output voltage is the same as the output voltage of the torque sensor, the current sensor using a torque sensor comprising a motor control unit (MCU) for determining the operation of the current sensor as safe (Safe) To provide an electronic control device to check the central point.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

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

ECU (Electronic Control Unit) 120 according to a preferred embodiment of the present invention is connected to various sensors, such as the motor 160 to determine the driving situation, such as the torque sensor 110, input from the torque sensor 110, etc. The detected electric signal is detected to detect the driving situation by the driver, and outputs a supply current for controlling the driving torque of the motor 160 to be suitable for 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 160 generates and transmits auxiliary power for smooth steering according to the supply current transmitted from the ECU 120.

In addition, the ECU 120 according to a preferred embodiment of the present invention includes a motor control unit (MCU) 130, an inverter 140, and a current sensor 150. Include.

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 160.

The MCU 130 according to the preferred embodiment of the present invention senses the output of the current sensor 150 at a time when power is supplied to the ECU 120 and the initial operation is checked to detect whether the current sensor 150 is malfunctioning. When the output of the current sensor 150 is inputted with a midpoint based on the output of the torque sensor 110, the current sensor 150 is determined to be safe, and the positive (+) or the negative (-) is not the midpoint. When the output of is detected, the current sensor 150 is determined as a fail (Fail).

That is, by using the current sensor 150 indicating the output of the positive (+) or the negative (-) with respect to the center point in the same steering direction as the torque sensor 110, the present invention is It is to check whether the current sensor 150 is abnormal based on the output. That is, in the present invention, the output of the current sensor 150 is always positive (+) or negative as in the torque sensor 110 at a predetermined time when the driver does not operate the steering in the EPS (Electronic Power Steering) system. It uses the fact that it outputs the midpoint instead of the negative output. In particular, at the initial operating time before the ECU 120 operates, i.e., before the fail-safe relay is activated, the current sensor 150 outputs an output other than the center of gravity of the torque sensor 110. If so, it is determined that the current sensor 150 is a fail.

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 for algorithms and the like, and EEPROM (Electrically Erasable Program ROM) for storing the central value of the current sensor 150, a microprocessor executes various software stored in the non-volatile memory, And a volatile memory such as random access memory (RAM) for storing temporary data.

The inverter 140 converts a direct current into an alternating current and supplies power to the motor 160. The inverter 140 supplies a supply current to the motor 160 under the control of the MCU 130. That is, the inverter 140 controls the operation of the motor 160 by varying the supply current supplied to the motor 160 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 160, the inverter 140 supplies three-phase alternating current power to the motor 160.

The current sensor 150 is attached to a connection between the inverter 140 and the motor 160, and is a current sensor that feeds back to the MCU 130 by detecting a current value of each phase.

2 is a graph confirming the midpoint of a current sensor using a torque sensor according to a preferred embodiment of the present invention.

As shown in FIG. 2, when the output of the torque sensor 110 and the output of the current sensor 150 are equally important, it is determined as safe as shown in FIG. Likewise, when the output of the torque sensor 110 and the output of the current sensor 150 show a positive (+) or a negative (-) output instead of the midpoint, it is determined as a fail.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, by using the output of the torque sensor instead of the A / D converter to monitor the control current of the motor in the EPS ECU, it does not change the MCU without affecting other logic or fail safe. The effect is that a motor control current monitoring circuit can be constructed.

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; And 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, receives an output voltage from the current sensor and the output voltage of the torque sensor and In comparison, if the output voltage of the current sensor is a positive or negative output with the output voltage of the torque sensor, the operation of the current sensor is determined as a fail, and the output of the current sensor A motor control unit (MCU) that determines the operation of the current sensor as safe when the voltage is the same as the output voltage of the torque sensor. Electronic control device for checking the center of the current sensor using a torque sensor comprising a. The method of claim 1, The motor controller applies power to the electronic controller and checks the midpoint of the current sensor at the time of checking the initial operation. The electronic controller checks the midpoint of the current sensor using a torque sensor. .

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