JP2011011567A5

JP2011011567A5 -

Info

Publication number: JP2011011567A5
Application number: JP2009154669A
Authority: JP
Filing date: 2009-06-30
Publication date: 2012-07-26

Description

上記の課題を解決するため、請求項１に記載の発明は、
ステアリング機構に操舵補助力を与える直流モータと、
車両の車速及びステアリングの操作により発生する操舵トルクから電流指令値を生成する電流指令値演算手段と、
前記電流指令値演算手段より演算された電流指令値に基づきモータ制御信号を出力するモータ制御手段と、
前記モータ制御信号に基づき前記直流モータに対して駆動電力を出力するモータ駆動回路と、を備え、
前記モータ駆動回路は、
Ｈブリッジ型に接続された第１及び第２のアームと、
前記第１のアームに配置された第１及び第２のスイッチング素子と、
前記第２のアームに配置された第１及び第２のスイッチング素子と、を有し、
前記モータ制御手段は、
第1アームの第1のスイッチング素子及び第２アームの第２のスイッチング素子を含む正回路を制御することで前記直流モータを正回転させ、第１アームの第２のスイッチング素子及び第２アームの第１のスイッチング素子を含む逆回路を制御することで前記直流モータを逆回転させる電動パワーステアリング制御装置であって、
前記モータ制御手段は、
前記スイッチング素子のオン故障を検出するスイッチング素子オン故障検出手段と、
前記スイッチング素子オン故障検出手段によってスイッチング素子のオン故障が検出された場合に、前記スイッチング素子を制御する異常処理制御手段と、を含み、
前記異常処理制御手段は、前記正回路または前記逆回路が制御状態であって、その回路に含まれる２個のスイッチング素子のうち、１個のスイッチング素子がオン故障と判断された場合には、
直流モータの回転指令方向が同一方向である期間は、オン故障したスイッチング素子とは別のスイッチング素子はＰＷＭ制御を行い、残りの回路に含まれる２個のスイッチング素子はオフ制御とする制御処理を選択することを、要旨とする。 In order to solve the above problems, the invention described in claim 1
A direct current motor that provides steering assist force to the steering mechanism;
Current command value calculation means for generating a current command value from the vehicle torque and steering torque generated by steering operation;
Motor control means for outputting a motor control signal based on the current command value calculated by the current command value calculation means;
A motor drive circuit that outputs drive power to the DC motor based on the motor control signal,
The motor drive circuit is
First and second arms connected in an H-bridge form;
First and second switching elements disposed on the first arm;
First and second switching elements disposed on the second arm,
The motor control means includes
The DC motor is rotated forward by controlling a positive circuit including the first switching element of the first arm and the second switching element of the second arm, and the second switching element and the second arm of the first arm are rotated. An electric power steering control device that reversely rotates the DC motor by controlling a reverse circuit including a first switching element,
The motor control means includes
A switching element on-failure detecting means for detecting an on-failure of the switching element;
An abnormality processing control means for controlling the switching element when an on-failure of the switching element is detected by the switching element on-failure detection means,
When the normal circuit or the reverse circuit is in a controlled state and one of the two switching elements included in the circuit is determined to be an on failure, the abnormality processing control means
During the period in which the rotation command directions of the DC motor are the same direction, a control process is performed in which a switching element different from the on-failed switching element performs PWM control, and the two switching elements included in the remaining circuits are turned off. The gist is to select.

上記構成によれば、スイッチング素子のオン故障を検出した場合に、オン故障したスイッチング素子および運転状況によって異常処理制御方法を選択できるようにした。即ち、１個のスイッチング素子がオン故障しても直流モータの回転指令方向が変化しなければオン故障したスイッチング素子とは別の正常なスイッチング素子をＰＷＭ制御することで連続して操舵補助力が得られる。
その結果、回転指令方向が同一方向である期間では、旋回操舵時に急に操舵補助力がなくなり、車両がふらつく等の操舵フィーリングの悪化を防止することができる。 According to the above configuration, when an on-failure of a switching element is detected, an abnormality processing control method can be selected depending on the on-failure switching element and the operation status. That is, if the rotation command direction of the DC motor does not change even if one switching element fails to turn on, the steering assist force can be continuously increased by PWM control of a normal switching element different from the switching element that has turned on. can get.
As a result, during the period in which the rotation command directions are the same direction, the steering assist force suddenly disappears during turning steering , and deterioration of the steering feeling such as the vehicle fluctuating can be prevented.

請求項２に係る発明は、請求項１に記載の発明において、前記異常処理制御手段は、前記正回路または前記逆回路が制御状態であって、その回路に含まれる２個のスイッチング素子のうち、１個のスイッチング素子がオン故障と判断された場合には、
その回転指令方向が逆転することを条件として、全スイッチング素子をオフ制御とする制御処理を選択することを、要旨とする。 According to a second aspect of the present invention, in the first aspect of the invention, the abnormality processing control unit is configured such that the normal circuit or the reverse circuit is in a controlled state, and the switching circuit is included in two switching elements included in the circuit. If one switching element is determined to be on-failure,
The gist is to select a control process for turning off all the switching elements on condition that the rotation command direction is reversed.

上記構成によれば、１個のスイッチング素子がオン故障した場合に、オン故障したスイッチング素子を継続して使用しても、モータの回転指令方向が逆転した瞬時に、全スイッチング素子をオフ制御するので、アーム短絡によってスイッチング素子が焼損することを防止できる。 According to the above configuration, when one switching element fails to be on, even if the on-failed switching element is continuously used, all the switching elements are off-controlled at the moment when the rotation command direction of the motor is reversed. Therefore, it is possible to prevent the switching element from burning out due to the arm short circuit.

請求項３に係る発明は、請求項１または請求項２に記載の発明において、前記スイッチング素子オン故障検出手段は、前記直流モータが右回転指令中または左回転指令中のＰＷＭ制御のオフ制御時に、前記直流モータの両端の端子電圧が回転指令方向に応じて、所定値より大きいか、小さいかにより行なわれることを、要旨とする。
上記構成によれば、モータの駆動時にスイッチング素子オン故障が検出できるようにしたので、高速で、高精度なスイッチング素子オン故障が検出できる。 According to a third aspect of the present invention, in the first or second aspect of the present invention, the switching element on-failure detecting means is configured to turn off the PWM control when the DC motor is in a right rotation command or a left rotation command. The gist is that the terminal voltage at both ends of the DC motor is determined depending on whether it is larger or smaller than a predetermined value according to the rotation command direction.
According to the above configuration, since the switching element on failure can be detected when the motor is driven, the switching element on failure can be detected at high speed and with high accuracy.

請求項１に係る発明によれば、スイッチング素子のオン故障を検出した場合に、オン故障したスイッチング素子および運転状況によって異常処理制御方法を選択できるようにしたので、旋回操舵時に急に操舵補助力がなくなり車両がふらつく等の操舵フィーリングの悪化を防止することができる。
即ち、１個のスイッチング素子がオン故障しても直流モータの回転指令方向が変化しなければオン故障したスイッチング素子とは別の正常なスイッチング素子をＰＷＭ制御することで連続して操舵補助力が得られるので、回転指令方向が同一方向である期間では、急に操舵補助力がなくなり車両がふらつく等の操舵フィーリングの悪化を防止することができる。
請求項２に係る発明によれば、１個のスイッチング素子がオン故障した場合に、オン故障したスイッチング素子を継続して使用しても、直流モータの回転指令方向が逆転した瞬時に、全スイッチング素子をオフ制御するので、アーム短絡によってスイッチング素子が焼損することを防止できる。
請求項３に係る発明によれば、モータの駆動時にスイッチング素子オン故障が検出できるようにしたので、高速で、高精度なスイッチング素子オン故障が検出できる。 According to the first aspect of the present invention, when an on-failure of a switching element is detected, the abnormality processing control method can be selected according to the on-failure switching element and the driving situation. It is possible to prevent the steering feeling from deteriorating, for example, when the vehicle disappears.
That is, if the rotation command direction of the DC motor does not change even if one switching element fails to turn on, the steering assist force can be continuously increased by PWM control of a normal switching element different from the switching element that has turned on. As a result, during the period in which the rotation command directions are the same direction, it is possible to prevent the steering feeling from deteriorating, such as sudden steering power loss and vehicle flickering.
According to the second aspect of the present invention, when one switching element is on-failed, even if the on-failed switching element is continuously used, all switching is performed at the moment when the rotation command direction of the DC motor is reversed. Since the element is controlled to be turned off, the switching element can be prevented from being burned out due to the arm short circuit.
According to the third aspect of the present invention, since the switching element ON failure can be detected when the motor is driven, the switching element ON failure can be detected at high speed and with high accuracy.

まず、ＭＯＤフラグが１か否かを判定する（ステップＳ３００）。そして、ＭＯＤフラグが１の場合（ステップＳ３００：ＹＥＳ）には、モータの回転を停止させ（ステップＳ３１２）、この処理を終わる。 First, it is determined whether or not the MOD flag is 1 (step S300). If the MOD flag is 1 (step S300: YES), the rotation of the motor is stopped (step S312), and this process is terminated.

次に、上記ステップＳ３０２で、ＭＯＤフラグが３でない場合（ステップＳ３０２：ＮＯ）には、ＭＯＤフラグが４か否かを判定する（ステップＳ３０３）。そして、ＭＯＤフラグが４の場合（ステップＳ３０３：ＹＥＳ）には、モータの回転を停止させ（ステップＳ３４２）、この処理を終わる。 Next, when the MOD flag is not 3 in step S302 (step S302: NO), it is determined whether or not the MOD flag is 4 (step S303). If the MOD flag is 4 (step S303: YES), the rotation of the motor is stopped (step S342), and this process is terminated.

Claims

A direct current motor that provides steering assist force to the steering mechanism;
Current command value calculation means for generating a current command value from the vehicle torque and steering torque generated by steering operation;
Motor control means for outputting a motor control signal based on the current command value calculated by the current command value calculation means;
A motor drive circuit that outputs drive power to the DC motor based on the motor control signal,
The motor drive circuit is
First and second arms connected in an H-bridge form;
First and second switching elements disposed on the first arm;
First and second switching elements disposed on the second arm,
The motor control means includes
The DC motor is rotated forward by controlling a positive circuit including the first switching element of the first arm and the second switching element of the second arm, and the second switching element and the second arm of the first arm are rotated. An electric power steering control device that reversely rotates the DC motor by controlling a reverse circuit including a first switching element,
The motor control means includes
A switching element on-failure detecting means for detecting an on-failure of the switching element;
An abnormality processing control means for controlling the switching element when an on-failure of the switching element is detected by the switching element on-failure detection means,
When the normal circuit or the reverse circuit is in a controlled state and one of the two switching elements included in the circuit is determined to be an on failure, the abnormality processing control means
During the period in which the rotation command directions of the DC motor are the same direction, a control process is performed in which a switching element different from the on-failed switching element performs PWM control, and the two switching elements included in the remaining circuits are turned off. An electric power steering control device characterized by being selected.

When the normal circuit or the reverse circuit is in a controlled state and one of the two switching elements included in the circuit is determined to be an on failure, the abnormality processing control means
2. The electric power steering control device according to claim 1, wherein a control process for turning off all the switching elements is selected on condition that the rotation command direction is reversed . 3.

The switching element ON failure detection means is configured to determine whether the terminal voltage at both ends of the DC motor is greater than a predetermined value in accordance with the rotation command direction when the DC motor is in the right rotation command or the PWM control OFF control during the left rotation command. the electric power steering control apparatus according to claim 1 or claim 2, characterized in Rukoto performed by or smaller.