JP4761015B2

JP4761015B2 - Vehicle steering device

Info

Publication number: JP4761015B2
Application number: JP2001177153A
Authority: JP
Inventors: 友保嘉田
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2001-06-12
Filing date: 2001-06-12
Publication date: 2011-08-31
Anticipated expiration: 2021-06-12
Also published as: JP2002362397A

Description

【０００１】
【発明の属する技術分野】
本発明は、いわゆるステアバイワイヤシステムを採用した車両の操舵装置に関する。
【０００２】
【従来の技術】
ステアバイワイヤシステムを採用した車両においては、ステアリングホイールを模した操作部材を車輪に機械的に連結することなく、その操作部材の回転に応じて駆動される操舵用アクチュエータの動きを、その動きに応じて舵角が変化するように車輪に伝達している。そのため、車輪と路面との間の摩擦に基づく操舵抵抗やセルフアライニングトルクは、その操作部材には伝達されない。
【０００３】
そこで、その操作部材を直進位置に戻す方向の反力を作用させることで、ステアリングホイールが車輪に機械的に連結された通常の車両と同様に、ドライバーに操舵フィーリングを与え、また、操作部材を直進位置に復帰させている。その反力を作用させるため、その操作部材の回転量を検出するセンサと、そのセンサにより検出した回転量に応じて反力を発生する反力アクチュエータを用いている。従来、その反力の大きさは操作部材の回転量に比例するものとされていた。
【０００４】
【発明が解決しようとする課題】
その反力の大きさを操作部材の回転量に比例させる場合、その操作部材の回転量と反力アクチュエータの駆動電圧とは比例するものとされていた。
【０００５】
その操作部材の回転量の増大に対する反力アクチュエータの駆動電圧の増大割合が小さい場合、操作部材を直進位置へ戻す方向の反力が小さくなる。そのため、操作後に操作部材が自動的に直進位置近傍に戻らなくなり、ドライバーが操作部材を直進位置近傍に戻す手間が生じる。
【０００６】
その操作部材の回転量の増大に対する反力アクチュエータの駆動電圧の増大割合が大きい場合、操作部材を直進位置へ戻す方向の反力は大きくなるので、操作後に操作部材は自動的に直進位置近傍に復帰する。しかし、復帰速度が等速に近くなり、直進位置近傍で急に復帰動作が止まるという不自然な動作をし、また、その復帰時に操作部材に手を添えている場合はドライバーに不自然な感覚を与える。また、操作部材の回転量を大きくすると反力が大きくなるため、軽い操舵フィーリングに設定することができなくなる。
【０００７】
【課題を解決するための手段】
本発明の車両の操舵装置は、操作部材と、その操作部材の回転に応じて駆動される操舵用アクチュエータと、その操作部材を車輪に機械的に連結することなく、その操舵用アクチュエータの動きに応じて舵角が変化するように、その動きを車輪に伝達する機構と、その操作部材を直進位置に復帰させる方向に作用する反力を発生する反力アクチュエータと、その操作部材の直進位置からの回転量を求める手段と、その回転量が増大しているか減少しているかを判断する手段と、その回転量と反力の大きさとの間の予め定められた対応関係を記憶する手段と、その記憶した関係に基づき求めた回転量に対応する反力が発生するように、その反力アクチュエータを制御する手段とを備え、その対応関係は、その回転量の増減に対応して反力の大きさが増減すると共に、その回転量が減少する時は増大する時よりも反力の大きさが大きくなるように定められていることを特徴とする。
本発明によれば、操作部材を直進位置に戻す方向の反力の大きさは、その操作部材が直進位置に戻る時は直進位置から離れる時よりも大きくされる。これにより、その操作部材の回転量の増大に対する反力の大きさの増大割合を大きくすることなく、直進位置に近づくにつれて操作部材の回転加速度を緩やかにして操作部材に自然な動作をさせ、しかも、操作後に操作部材が自動的に直進位置近傍に戻らなくなるのを防止できる。
【０００８】
さらに本発明においては、その操作部材の回転速度を求める手段を備え、その回転量が減少する時の反力の大きさと増大する時の反力の大きさとの差は、その回転速度の大きさが小さい程に大きくされる。
これにより、操作部材をより確実かつ自然な動きで直進位置近傍に戻すように、その反力の大きさの差が設定される。
この場合、その回転速度の大きさが第１設定値以上である時、その回転量が減少する時の反力の大きさと増大する時の反力の大きさとの差は零とされるのが好ましい。これにより、直進方向への操舵速度が充分に大きい場合に必要以上の反力が作用するのを防止できる。
また、その回転速度の大きさが第１設定値よりも小さな第２設定値未満である時その回転量が減少する時の反力の大きさと増大する時の反力の大きさとの差は零とされるのが好ましい。これにより、直進方向へ緩やかに操舵を行う場合に、その反力の大きさの差により緩やかな操舵が妨げられるのを防止できる。
【０００９】
あるいは本発明においては、その回転量が減少する時の反力の大きさと増大する時の反力の大きさとの差と、その操作部材の回転量に対する反力の大きさの変化割合とは変更可能とされ、その回転量が減少する時の反力の大きさと増大する時の反力の大きさとの差は、その操作部材の回転量に対する反力の大きさの変化割合が小さい程に大きくすることが可能とされている。
これにより、操作部材の回転量の増大に対する反力の大きさの増大割合が大きく操舵フィーリングが重い場合でも、また、その増大割合が小さく操舵フィーリングが軽い場合でも、操作部材をより自然な動きで直進位置近傍に戻すように、その反力の大きさの差を設定できる。
【００１０】
その操作部材の回転量が直進位置から設定範囲内にある時は、その反力アクチュエータによる反力の発生は解除されるのが好ましい。
これにより、直進位置近傍において操作部材の動きの遊びを確保できる。
【００１１】
【発明の実施の形態】
図１に示す車両の操舵装置は、ステアリングホイールを模した操作部材１と、その操作部材１の回転に応じて駆動される操舵用アクチュエータ２と、その操作部材１を車輪４に機械的に連結することなく、その操舵用アクチュエータ２の動きに応じて舵角が変化するように、その動きを車輪４に伝達するステアリングギヤ３と、その操作部材１を直進位置に復帰させる方向に作用する反力を発生する反力アクチュエータ１９とを備える。
【００１２】
その操舵用アクチュエータ２は、例えば公知のブラシレスモータ等の電動モータにより構成できる。そのステアリングギヤ３は、その操舵用アクチュエータ２の出力シャフトの回転運動をステアリングロッド７の直線運動に変換する例えばボールねじ機構などの運動変換機構により構成されている。そのステアリングロッド７の動きがタイロッド８とナックルアーム９を介して車輪４に伝達され、その車輪４のトー角が変化する。そのステアリングギヤ３は、公知のものを用いることができ、操舵用アクチュエータ２の動きを舵角が変化するように車輪４に伝達できれば構成は限定されない。なお、操舵用アクチュエータ２が駆動されていない状態では、車輪４はセルフアライニングトルクにより直進位置に復帰できるようにホイールアラインメントが設定されている。
【００１３】
その操作部材１は、車体側により回転可能に支持される回転シャフト１０に連結されている。その回転シャフト１０に反力アクチュエータ１９の出力シャフトが一体化されている。その反力アクチュエータ１９はブラシレスモータ等の電動モータにより構成できる。
【００１４】
その操作部材１の直進位置からの回転量を求める手段として、その操作部材１の直進位置からの回転角度δｈを検出する角度センサ１１が設けられている。車両の舵角δを検出する手段として、ステアリングロッド７の作動量を検出するポテンショメータにより構成される舵角センサ１３が設けられている。車速Ｖを検出する速度センサ１４が設けられている。その角度センサ１１、舵角センサ１３、速度センサ１４は、コンピュータにより構成される制御装置２０に接続されている。
【００１５】
その制御装置２０は、駆動回路２２を介して操舵用アクチュエータ２を制御する。例えば、その操作部材１の回転角度δｈと車速Ｖと目標舵角との間の関係を予め定めて記憶し、その舵角δと目標舵角との偏差をなくすように駆動回路２２を介して操舵用アクチュエータ２の駆動信号を出力する。その回転角度δｈと車速Ｖと目標舵角との間の関係は、車速Ｖが大きくなる程に回転角度δｈに対応する目標舵角を小さくすることで、低速での旋回性能の向上と高速での走行安定性とを図ることができる。なお、このような操舵用アクチュエータ２の制御方法は特に限定されず、操作部材１の回転に応じて操舵用アクチュエータ２が駆動されるものであれば良く、例えば、車両のヨーレートセンサを設け、操作部材１の回転角度δｈと目標ヨーレートとの間の関係を予め定めて記憶し、そのヨーレートと目標ヨーレートとの偏差をなくすように駆動回路２２を介して操舵用アクチュエータ２の駆動信号を出力してもよい。
【００１６】
その制御装置２０は、その操作部材１の回転量と反力の大きさとの間の予め定められた対応関係を記憶する。その対応関係として、本実施形態においては、図２に示す関係と図３に示す関係とを記憶する。
【００１７】
その図２は、回転角度δｈと反力アクチュエータ１９への電圧指示値Ｖ１との関係を示し、回転角度δｈと電圧指示値Ｖ１の値は操作部材１が直進位置よりも左右一方に位置する時は正、左右他方に位置する時は負とされる。その回転角度δｈが直進位置から設定範囲内（図示例では±１０度以内）にある時は、その電圧指示値Ｖ１が零とされて反力アクチュエータ１９による反力の発生は解除され、その設定範囲を超えると、回転角度δｈの増大に電圧指示値が比例して反力が増大するものとされている。
【００１８】
その図３は、回転角度δｈが減少し、且つ、回転角度δｈが直進位置から上記設定範囲を超える場合における、回転速度Ｒと反力アクチュエータ１９への電圧付加指示値Ｖ２との関係を示し、その回転速度Ｒの値は操作部材１が直進位置よりも左右一方に位置する時は正、左右他方に位置する時は負とされる。制御装置２０は、時系列に検知される回転角度δｈの検出値から操作部材１の回転速度Ｒを演算により求める。その回転速度Ｒの大きさが第１設定値以上（図示例では７００度／秒以上）である時、および、その回転速度Ｒの大きさが第１設定値よりも小さな第２設定値未満（図示例では１００度／秒未満）である時は、その電圧付加指示値Ｖ２は零とされ、両設定値間の値である時は回転速度Ｒの増大に電圧付加指示値Ｖ２が反比例して反力が減少するものとされている。
【００１９】
制御装置２０は、その記憶した関係に基づき求めた回転角度δｈと回転速度Ｒとに対応する反力が発生するように駆動回路２３を介して反力アクチュエータ１９を制御する。これにより、図２に示される関係を充足する回転角度δｈに対応する電圧指示値に応じた反力に、図３に示される関係を充足する回転速度Ｒに対応する電圧付加指示値に応じた反力を付加した反力を、反力アクチュエータ１９は発生するものとされる。すなわち、その記憶される対応関係は、その回転角度δｈの増減に対応して反力の大きさが増減すると共に、その回転角度δｈが減少する時は増大する時よりも反力の大きさが大きくなるように定められている。その回転角度δｈが減少する時の反力の大きさと増大する時の反力の大きさとの差は、図３に示される関係を充足する回転速度Ｒに対応する電圧付加指示値に応じた反力、すなわち付加反力であり、その回転速度Ｒの大きさが小さい程に大きくされる。また、その付加反力の大きさは回転速度Ｒの大きさが第１設定値以上と第２設定値未満である時は零とされる。また、その回転角度δｈが直進位置から設定範囲内にある時は、その反力アクチュエータ１９による反力の発生は解除される。
【００２０】
その反力アクチュエータ１９の制御手順を図４のフローチャートを参照して説明する。まず、操作部材１の回転角度δｈの検出値を読み込み（ステップ１）、その回転角度δｈが直進位置から設定範囲内（±１０度以内）にあるか否かを判断し（ステップ２）、その設定範囲内にあればステップ１に戻る。その回転角度δｈが直進位置から設定範囲を超える時、その回転角度δｈに基づき操作部材１の回転速度Ｒを演算する（ステップ３）。次に、その回転角度δｈが直進位置から増大しているか減少しているかを判断する（ステップ４）。その回転角度δｈが増大あるいは変化していない場合、図２に示す関係に従った回転角度δｈに対応する電圧指示値Ｖ１を反力アクチュエータ１９に印加し、操作部材１を直進位置に復帰させる方向に作用する反力を発生させ（ステップ５）、ステップ１に戻る。ステップ４において回転角度δｈが直進位置から減少している場合、回転速度Ｒが上記第１設定値（７００度／秒）未満で第２設定値（１００度／秒）以上であるか否かを判断する（ステップ６）。その回転速度Ｒが第１設定値以上あるいは第２設定値未満である場合、ステップ５において反力を発生させる。その回転速度Ｒが第１設定値未満で第２設定値以上である場合、図２に示す関係に従った回転角度δｈに対応する電圧指示値Ｖ１と図３に示す関係に従った回転速度Ｒに対応する電圧付加指示値Ｖ２との和を反力アクチュエータ１９に印加し、操作部材１を直進位置に復帰させる方向に作用する反力を発生させ（ステップ７）、ステップ１に戻る。なお、反力アクチュエータ１９への印加電圧あるいは印加電流を検出するセンサを設け、その検出値に基づいて印加電圧が目標値になるようにフィードバック制御してもよい。
【００２１】
上記実施形態によれば、操作部材１を直進位置に戻す方向の反力の大きさは、その操作部材１が直進位置に戻る時は直進位置から離れる時よりも上記付加反力だけ大きくされる。これにより、操作部材１の回転角度δｈの増大に対する反力の大きさの増大割合を大きくすることなく、直進位置に近づくにつれて操作部材１の回転加速度を緩やかにして操作部材１に自然な動作をさせ、しかも、操作後に操作部材１が自動的に直進位置近傍に戻らなくなるのを防止できる。その回転角度δｈが減少する時の上記付加反力の大きさは、操作部材１の回転速度Ｒの大きさが小さい程に大きくされるので、操作部材１をより確実かつ自然な動きで直進位置近傍に戻すように、その付加反力の大きさが設定される。その回転速度Ｒの大きさが第１設定値以上である時、上記付加反力の大きさは零とされるので、直進方向への操舵速度が充分に大きい場合に不必要な付加反力が作用するのを防止できる。また、その回転速度Ｒの大きさが第２設定値未満である時、その付加反力の大きさは零とされるので、直進方向へ緩やかに操舵を行う場合に、その付加反力により緩やかな操舵が妨げられるのを防止できる。さらに、操作部材１の回転角度δｈが直進位置から設定範囲内にある時は、反力アクチュエータ１９による反力の発生は解除されるので、直進位置近傍において操作部材１の動きの遊びを確保できる。
【００２２】
本発明は上記実施形態に限定されない。例えば、図２、図３に示す関係は一例であってこれに限定されるものではなく、付加反力の大きさと、その操作部材の回転量に対する反力の大きさの変化割合とが変更可能なように、操作部材１の回転角度δｈの変化に対する反力の大きさの変化割合と、各回転速度Ｒに対する電圧指示値とが変更可能とされてもよい。これにより、例えば、図２において破線で示すように、その回転角度δｈに対する電圧指示値の変化割合を上記実施形態よりも大きくなるように変更する時は、図３において破線で示すように、各回転速度Ｒに対する電圧指示値を上記実施形態よりも小さくなるように変更可能とされる。これにより、その付加反力の大きさは、その操作部材の回転量に対する反力の大きさの変化割合が大きい程に小さくされ、操作部材１の回転角度δｈの増大に対する反力の大きさの増大割合が大きく操舵フィーリングが重い場合でも、また、その増大割合が小さく操舵フィーリングが軽い場合でも、操作部材１をより自然な動きで直進位置近傍に戻すように、その反力の大きさの差を設定できる。
【００２３】
【発明の効果】
本発明によれば、ステアバイワイヤシステムを採用した車両において、操作部材をドライバーが直進位置に戻す手間をなくし、自動的に自然な動作で直進位置に復帰させることができ、その復帰時に操作部材に手を添えている場合はドライバーに不自然な感覚を与えることがなく、適度な手応え感を得ることができる車両の操舵装置を提供できる。
【図面の簡単な説明】
【図１】本発明の実施形態の車両の操舵装置の構成説明図
【図２】本発明の実施形態の車両の操舵装置における回転角度と反力アクチュエータへの電圧指示値との関係を示す図
【図３】本発明の実施形態の車両の操舵装置における回転速度と反力アクチュエータへの電圧付加指示値との関係を示す図
【図４】本発明の実施形態の車両の操舵装置における反力アクチュエータの制御手順を示すフローチャート
【符号の説明】
１操作部材
２操舵用アクチュエータ
３ステアリングギヤ
４車輪
１１角度センサ
１９反力アクチュエータ
２０制御装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle steering apparatus employing a so-called steer-by-wire system.
[0002]
[Prior art]
In a vehicle that employs a steer-by-wire system, the operation of the steering actuator driven according to the rotation of the operation member according to the movement of the operation member imitating the steering wheel is not mechanically coupled to the wheel. The steering angle is transmitted to the wheels to change. Therefore, steering resistance and self-aligning torque based on friction between the wheels and the road surface are not transmitted to the operation member.
[0003]
Therefore, by applying a reaction force in a direction to return the operating member to the straight traveling position, the steering wheel is given a steering feeling to the driver in the same manner as in a normal vehicle in which the steering wheel is mechanically connected to the wheel. Is returned to the straight position. In order to apply the reaction force, a sensor that detects the rotation amount of the operation member and a reaction force actuator that generates a reaction force according to the rotation amount detected by the sensor are used. Conventionally, the magnitude of the reaction force has been proportional to the amount of rotation of the operation member.
[0004]
[Problems to be solved by the invention]
When the magnitude of the reaction force is proportional to the rotation amount of the operation member, the rotation amount of the operation member is proportional to the drive voltage of the reaction force actuator.
[0005]
When the increase rate of the drive voltage of the reaction force actuator with respect to the increase in the rotation amount of the operation member is small, the reaction force in the direction of returning the operation member to the straight traveling position becomes small. For this reason, the operation member does not automatically return to the vicinity of the rectilinear position after the operation, and the driver needs to return the operation member to the vicinity of the rectilinear position.
[0006]
When the rate of increase of the driving force of the reaction force actuator with respect to the increase in the amount of rotation of the operating member is large, the reaction force in the direction to return the operating member to the straight running position increases. Return. However, if the return speed is close to a constant speed and the return operation suddenly stops near the straight-ahead position, and if the operation member is touched at the time of return, the driver feels unnatural. give. Further, since the reaction force increases when the rotation amount of the operation member is increased, it is not possible to set a light steering feeling.
[0007]
[Means for Solving the Problems]
The vehicle steering apparatus according to the present invention includes an operation member, a steering actuator that is driven according to the rotation of the operation member, and the movement of the steering actuator without mechanically connecting the operation member to a wheel. A mechanism that transmits the movement to the wheels, a reaction force actuator that generates a reaction force that acts in a direction to return the operation member to the rectilinear position, and a rectilinear position of the operation member so that the steering angle changes accordingly Means for determining the amount of rotation, means for determining whether the amount of rotation is increasing or decreasing, means for storing a predetermined correspondence between the amount of rotation and the magnitude of the reaction force, Means for controlling the reaction force actuator so that a reaction force corresponding to the rotation amount obtained based on the stored relationship is generated, and the correspondence relationship corresponds to the increase or decrease of the rotation amount. big There as well as increasing or decreasing, characterized in that it is defined as the magnitude of the reactive force is greater than the time to increase when the amount of rotation is reduced.
According to the present invention, the magnitude of the reaction force in the direction in which the operating member is returned to the rectilinear position is made larger when the operating member returns to the rectilinear position than when the operating member leaves the rectilinear position. As a result, without increasing the increase rate of the reaction force with respect to the increase in the rotation amount of the operation member, the rotation acceleration of the operation member is moderated as it approaches the straight traveling position, and the operation member is caused to perform a natural operation. Thus, it is possible to prevent the operating member from automatically returning to the vicinity of the straight traveling position after the operation.
[0008]
Further, in the present invention, there is provided means for obtaining the rotation speed of the operation member, and the difference between the magnitude of the reaction force when the rotation amount decreases and the magnitude of the reaction force when the rotation amount increases is the magnitude of the rotation speed. Ru is large enough is small.
Thereby, the difference in the magnitude of the reaction force is set so that the operating member is returned to the vicinity of the straight position with more reliable and natural movement.
In this case, when the rotation speed is greater than or equal to the first set value, the difference between the magnitude of the reaction force when the rotation amount decreases and the magnitude of the reaction force when the rotation amount increases is zero. preferable. Thereby, it is possible to prevent an excessive reaction force from acting when the steering speed in the straight traveling direction is sufficiently high.
Further, when the rotational speed is less than the second set value which is smaller than the first set value, the difference between the magnitude of the reaction force when the amount of rotation decreases and the magnitude of the reaction force when it increases is zero. It is preferable that As a result, when the steering is gently performed in the straight traveling direction, it is possible to prevent the gentle steering from being hindered by the difference in the magnitude of the reaction force.
[0009]
Alternatively, in the present invention, the difference between the magnitude of the reaction force when the rotation amount decreases and the magnitude of the reaction force when the rotation amount increases and the rate of change of the reaction force with respect to the rotation amount of the operating member are changed. The difference between the magnitude of the reaction force when the amount of rotation decreases and the magnitude of the reaction force when it increases increases as the change rate of the magnitude of the reaction force with respect to the amount of rotation of the operating member decreases. that that has been and can be.
As a result, even when the increase ratio of the reaction force with respect to the increase in the rotation amount of the operation member is large and the steering feeling is heavy, or even when the increase ratio is small and the steering feeling is light, the operation member is made more natural. The difference in the magnitude of the reaction force can be set so as to return to the vicinity of the straight position by movement.
[0010]
When the rotation amount of the operating member is within the set range from the straight advance position, it is preferable that the generation of the reaction force by the reaction force actuator is cancelled.
Thereby, the play of the movement of the operating member can be secured in the vicinity of the straight traveling position.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The vehicle steering apparatus shown in FIG. 1 is an operation member 1 that imitates a steering wheel, a steering actuator 2 that is driven according to the rotation of the operation member 1, and the operation member 1 that is mechanically connected to a wheel 4. The steering gear 3 that transmits the movement to the wheel 4 and the operation member 1 acting in a direction to return the operation member 1 to the straight traveling position so that the rudder angle changes according to the movement of the steering actuator 2. And a reaction force actuator 19 that generates force.
[0012]
The steering actuator 2 can be constituted by an electric motor such as a known brushless motor. The steering gear 3 is configured by a motion conversion mechanism such as a ball screw mechanism that converts the rotational motion of the output shaft of the steering actuator 2 into the linear motion of the steering rod 7. The movement of the steering rod 7 is transmitted to the wheel 4 through the tie rod 8 and the knuckle arm 9, and the toe angle of the wheel 4 changes. As the steering gear 3, a known one can be used, and the configuration is not limited as long as the movement of the steering actuator 2 can be transmitted to the wheels 4 so that the steering angle changes. In the state where the steering actuator 2 is not driven, the wheel alignment is set so that the wheel 4 can be returned to the straight position by the self-aligning torque.
[0013]
The operating member 1 is connected to a rotating shaft 10 that is rotatably supported by the vehicle body side. An output shaft of the reaction force actuator 19 is integrated with the rotary shaft 10. The reaction force actuator 19 can be constituted by an electric motor such as a brushless motor.
[0014]
An angle sensor 11 that detects a rotation angle δh of the operating member 1 from the rectilinear position is provided as means for obtaining the amount of rotation of the operating member 1 from the rectilinear position. As means for detecting the steering angle δ of the vehicle, a steering angle sensor 13 constituted by a potentiometer that detects the operation amount of the steering rod 7 is provided. A speed sensor 14 for detecting the vehicle speed V is provided. The angle sensor 11, the rudder angle sensor 13, and the speed sensor 14 are connected to a control device 20 configured by a computer.
[0015]
The control device 20 controls the steering actuator 2 via the drive circuit 22. For example, the relationship among the rotation angle δh of the operating member 1, the vehicle speed V and the target rudder angle is determined and stored in advance, and the drive circuit 22 is used to eliminate the deviation between the rudder angle δ and the target rudder angle. A drive signal for the steering actuator 2 is output. The relationship between the rotation angle δh, the vehicle speed V, and the target rudder angle is that, as the vehicle speed V increases, the target rudder angle corresponding to the rotation angle δh is reduced to improve the turning performance at low speed and at high speed. Driving stability can be achieved. The method for controlling the steering actuator 2 is not particularly limited as long as the steering actuator 2 is driven in accordance with the rotation of the operation member 1. For example, a vehicle yaw rate sensor is provided and the operation is performed. The relationship between the rotation angle δh of the member 1 and the target yaw rate is determined and stored in advance, and a drive signal for the steering actuator 2 is output via the drive circuit 22 so as to eliminate the deviation between the yaw rate and the target yaw rate. Also good.
[0016]
The control device 20 stores a predetermined correspondence between the rotation amount of the operation member 1 and the magnitude of the reaction force. As the correspondence relationship, in the present embodiment, the relationship shown in FIG. 2 and the relationship shown in FIG. 3 are stored.
[0017]
FIG. 2 shows the relationship between the rotation angle δh and the voltage instruction value V1 to the reaction force actuator 19, and the values of the rotation angle δh and the voltage instruction value V1 are determined when the operation member 1 is located on the left or right side of the straight traveling position. Is positive and negative when it is located on the other side. When the rotation angle δh is within a setting range (within ± 10 degrees in the illustrated example) from the straight-ahead position, the voltage instruction value V1 is set to zero, and the generation of the reaction force by the reaction force actuator 19 is canceled and the setting is made. When the range is exceeded, the reaction force increases in proportion to the voltage instruction value in proportion to the increase in the rotation angle δh.
[0018]
FIG. 3 shows the relationship between the rotation speed R and the voltage addition instruction value V2 to the reaction force actuator 19 when the rotation angle δh decreases and the rotation angle δh exceeds the set range from the straight advance position. The value of the rotational speed R is positive when the operating member 1 is positioned on the left or right side of the straight traveling position, and negative when the operating member 1 is positioned on the left or right side. The control device 20 obtains the rotational speed R of the operation member 1 by calculation from the detected value of the rotational angle δh detected in time series. When the rotation speed R is greater than or equal to the first set value (700 degrees / second or more in the illustrated example) and when the rotation speed R is less than the first set value and less than the second set value ( When it is less than 100 degrees / second in the illustrated example, the voltage addition instruction value V2 is zero, and when the value is between both set values, the voltage addition instruction value V2 is inversely proportional to the increase in the rotational speed R. The reaction force is supposed to decrease.
[0019]
The control device 20 controls the reaction force actuator 19 via the drive circuit 23 so that a reaction force corresponding to the rotation angle δh and the rotation speed R obtained based on the stored relationship is generated. As a result, the reaction force corresponding to the voltage instruction value corresponding to the rotation angle δh satisfying the relationship shown in FIG. 2 corresponds to the voltage addition instruction value corresponding to the rotation speed R satisfying the relationship shown in FIG. The reaction force actuator 19 generates a reaction force to which a reaction force is added. That is, the stored correspondence relationship is that the magnitude of the reaction force increases or decreases corresponding to the increase or decrease of the rotation angle δh, and the magnitude of the reaction force is greater when the rotation angle δh decreases than when it increases. It is determined to be large. The difference between the magnitude of the reaction force when the rotation angle δh is reduced and the magnitude of the reaction force when the rotation angle δh is increased is a reaction corresponding to the voltage addition instruction value corresponding to the rotation speed R satisfying the relationship shown in FIG. This is a force, that is, an additional reaction force, and is increased as the rotational speed R is smaller. The magnitude of the additional reaction force is zero when the rotational speed R is greater than or equal to the first set value and less than the second set value. Further, when the rotation angle δh is within the set range from the rectilinear position, generation of the reaction force by the reaction force actuator 19 is cancelled.
[0020]
The control procedure of the reaction force actuator 19 will be described with reference to the flowchart of FIG. First, the detected value of the rotation angle δh of the operation member 1 is read (step 1), and it is determined whether or not the rotation angle δh is within a set range (within ± 10 degrees) from the straight-ahead position (step 2). If it is within the set range, return to Step 1. When the rotation angle δh exceeds the set range from the straight traveling position, the rotation speed R of the operation member 1 is calculated based on the rotation angle δh (step 3). Next, it is determined whether the rotation angle δh has increased or decreased from the straight position (step 4). When the rotation angle δh does not increase or change, the voltage instruction value V1 corresponding to the rotation angle δh according to the relationship shown in FIG. 2 is applied to the reaction force actuator 19 to return the operating member 1 to the straight position. (Step 5), and the process returns to Step 1. When the rotation angle δh is decreased from the straight traveling position in step 4, it is determined whether or not the rotation speed R is less than the first set value (700 degrees / second) and greater than or equal to the second set value (100 degrees / second). Judgment is made (step 6). If the rotation speed R is equal to or higher than the first set value or less than the second set value, a reaction force is generated in step 5. When the rotation speed R is less than the first set value and greater than or equal to the second set value, the voltage instruction value V1 corresponding to the rotation angle δh according to the relationship shown in FIG. 2 and the rotation speed R according to the relationship shown in FIG. Is added to the reaction force actuator 19 to generate a reaction force acting in a direction to return the operating member 1 to the straight position (step 7), and the process returns to step 1. A sensor for detecting the applied voltage or applied current to the reaction force actuator 19 may be provided, and feedback control may be performed so that the applied voltage becomes a target value based on the detected value.
[0021]
According to the above embodiment, the magnitude of the reaction force in the direction to return the operating member 1 to the rectilinear position is made larger by the additional reaction force when the operating member 1 returns to the rectilinear position than when leaving the rectilinear position. . As a result, without increasing the rate of increase in the magnitude of the reaction force with respect to the increase in the rotation angle δh of the operating member 1, the operating member 1 can be operated naturally by reducing the rotational acceleration of the operating member 1 as it approaches the straight traveling position. Moreover, it is possible to prevent the operation member 1 from automatically returning to the vicinity of the straight position after the operation. Since the magnitude of the additional reaction force when the rotation angle δh decreases is increased as the rotation speed R of the operation member 1 is decreased, the operation member 1 is moved straightly in a more reliable and natural movement. The magnitude of the additional reaction force is set so as to return to the vicinity. When the rotational speed R is greater than or equal to the first set value, the magnitude of the additional reaction force is zero. Therefore, an unnecessary additional reaction force is generated when the steering speed in the straight direction is sufficiently high. It can be prevented from acting. Further, when the rotational speed R is less than the second set value, the magnitude of the additional reaction force is zero. Therefore, when the steering is gently performed in the straight traveling direction, the additional reaction force is moderated. Can be prevented from being disturbed. Further, when the rotation angle δh of the operation member 1 is within the set range from the straight position, the reaction force generated by the reaction force actuator 19 is released, so that play of the movement of the operation member 1 can be secured in the vicinity of the straight position. .
[0022]
The present invention is not limited to the above embodiment. For example, the relationship shown in FIG. 2 and FIG. 3 is an example and is not limited to this, and the magnitude of the additional reaction force and the change rate of the reaction force with respect to the rotation amount of the operation member can be changed. As described above, the change ratio of the magnitude of the reaction force with respect to the change of the rotation angle δh of the operation member 1 and the voltage instruction value for each rotation speed R may be changeable. Thus, for example, as shown by a broken line in FIG. 2, when changing the change rate of the voltage instruction value with respect to the rotation angle δh so as to be larger than that in the above embodiment, as shown by a broken line in FIG. The voltage instruction value for the rotation speed R can be changed to be smaller than that in the above embodiment. As a result, the magnitude of the additional reaction force is reduced as the rate of change in the magnitude of the reaction force with respect to the amount of rotation of the operating member increases, and the magnitude of the reaction force against the increase in the rotation angle δh of the operating member 1 is increased. Even when the increase ratio is large and the steering feeling is heavy, or even when the increase ratio is small and the steering feeling is light, the magnitude of the reaction force is set so that the operation member 1 is returned to the vicinity of the straight traveling position by a more natural movement. You can set the difference .
[0023]
【The invention's effect】
According to the present invention, in a vehicle adopting a steer-by-wire system, it is possible to eliminate the trouble of the driver returning the operation member to the straight-ahead position, and to automatically return to the straight-ahead position by natural operation. When a hand is attached, a vehicle steering device can be provided that does not give an unnatural feeling to the driver and can provide an appropriate feeling of response.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a vehicle steering apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a relationship between a rotation angle and a voltage instruction value to a reaction force actuator in a vehicle steering apparatus according to an embodiment of the present invention. FIG. 3 is a view showing a relationship between a rotation speed and a voltage addition instruction value to a reaction force actuator in the vehicle steering apparatus according to the embodiment of the present invention. FIG. 4 is a reaction force in the vehicle steering apparatus according to the embodiment of the present invention. Flow chart showing the control procedure of the actuator 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Operation member 2 Steering actuator 3 Steering gear 4 Wheel 11 Angle sensor 19 Reaction force actuator 20 Control apparatus

Claims

An operation member;
A steering actuator driven according to the rotation of the operation member;
A mechanism for transmitting the movement to the wheel so that the rudder angle changes according to the movement of the steering actuator without mechanically connecting the operation member to the wheel;
A reaction force actuator that generates a reaction force that acts in a direction to return the operation member to the rectilinear position;
Means for determining the rotation amount of the operating member from the straight position;
Means for determining whether the amount of rotation is increasing or decreasing;
Means for storing a predetermined correspondence between the amount of rotation and the magnitude of the reaction force;
Means for controlling the reaction force actuator so that a reaction force corresponding to the rotation amount obtained based on the stored relationship is generated ;
Means for determining the rotational speed of the operating member ,
The correspondence relationship is determined so that the magnitude of the reaction force increases or decreases corresponding to the increase or decrease of the rotation amount, and the magnitude of the reaction force becomes larger when the rotation amount decreases than when it increases .
The difference between the magnitude of the reaction force when the amount of rotation decreases and the magnitude of the reaction force when it increases increases as the rotational speed decreases .

When the rotation speed is at least one of the first set value and the rotation speed is less than the second set value smaller than the first set value, the rotation The vehicle steering apparatus according to claim 1, wherein the difference between the magnitude of the reaction force when the amount decreases and the magnitude of the reaction force when the amount increases is zero .

The difference between the magnitude of the reaction force when the amount of rotation decreases and the magnitude of the reaction force when it increases and the rate of change of the magnitude of the reaction force with respect to the amount of rotation of the operating member can be changed. The difference between the magnitude of the reaction force when the amount decreases and the magnitude of the reaction force when the amount increases can be increased as the change rate of the magnitude of the reaction force with respect to the rotation amount of the operating member is smaller. and it has a steering device for a vehicle according to claim 1 or 2.

An operation member;
A steering actuator driven according to the rotation of the operation member;
A mechanism for transmitting the movement to the wheel so that the rudder angle changes according to the movement of the steering actuator without mechanically connecting the operation member to the wheel;
A reaction force actuator that generates a reaction force that acts in a direction to return the operation member to the rectilinear position;
Means for determining the rotation amount of the operating member from the straight position;
Means for determining whether the amount of rotation is increasing or decreasing;
Means for storing a predetermined correspondence between the amount of rotation and the magnitude of the reaction force;
Means for controlling the reaction force actuator such that a reaction force corresponding to the rotation amount obtained based on the stored relationship is generated,
The correspondence relationship is determined so that the magnitude of the reaction force increases or decreases corresponding to the increase or decrease of the rotation amount, and the magnitude of the reaction force becomes larger when the rotation amount decreases than when it increases.
The difference between the magnitude of the reaction force when the amount of rotation decreases and the magnitude of the reaction force when it increases and the rate of change of the magnitude of the reaction force with respect to the amount of rotation of the operating member can be changed. The difference between the magnitude of the reaction force when the amount decreases and the magnitude of the reaction force when the amount increases can be increased as the change rate of the magnitude of the reaction force with respect to the rotation amount of the operating member is smaller. Tei Ru vehicles of the steering apparatus.

The vehicle steering apparatus according to any one of claims 1 to 4, wherein when the amount of rotation of the operating member is within a set range from the rectilinear position, generation of the reaction force by the reaction force actuator is canceled.