JPH0274471A - Rear wheel steering angle control device - Google Patents
Rear wheel steering angle control deviceInfo
- Publication number
- JPH0274471A JPH0274471A JP22688588A JP22688588A JPH0274471A JP H0274471 A JPH0274471 A JP H0274471A JP 22688588 A JP22688588 A JP 22688588A JP 22688588 A JP22688588 A JP 22688588A JP H0274471 A JPH0274471 A JP H0274471A
- Authority
- JP
- Japan
- Prior art keywords
- vehicle
- center
- gravity
- steering angle
- angle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005484 gravity Effects 0.000 claims abstract description 63
- 238000001514 detection method Methods 0.000 claims description 11
- 238000012937 correction Methods 0.000 claims description 4
- CLOMYZFHNHFSIQ-UHFFFAOYSA-N clonixin Chemical compound CC1=C(Cl)C=CC=C1NC1=NC=CC=C1C(O)=O CLOMYZFHNHFSIQ-UHFFFAOYSA-N 0.000 abstract 2
- 230000004044 response Effects 0.000 description 10
- 230000004043 responsiveness Effects 0.000 description 9
- 238000004364 calculation method Methods 0.000 description 7
- 230000008859 change Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000006870 function Effects 0.000 description 5
- 239000000725 suspension Substances 0.000 description 4
- 238000012546 transfer Methods 0.000 description 4
- 210000001015 abdomen Anatomy 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D7/00—Steering linkage; Stub axles or their mountings
- B62D7/06—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins
- B62D7/14—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering
- B62D7/15—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering characterised by means varying the ratio between the steering angles of the steered wheels
- B62D7/159—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering characterised by means varying the ratio between the steering angles of the steered wheels characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、車両の後輪舵角制御装置に関するものである
。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rear wheel steering angle control device for a vehicle.
（従来の技術）
この種の従来装置としては、例えば昭和６２年６月５日
に社団法人自動車技術会が開催した「４ＷＳ ＜四輪操
舵）車ニアクチイブ制御技術の最前線」シンポジウムの
前刷集第３４〜４１頁に記載されている「マツダ車速感
応型４輪操舵」に開示されているものがある。(Prior art) This type of conventional device is, for example, a preprint collection of the "4WS (Four-Wheel Steering) Frontline of Vehicle Near-Active Control Technology" symposium held by the Society of Automotive Engineers of Japan on June 5, 1986. There is one disclosed in "Mazda Vehicle Speed Sensitive Four-Wheel Steering" described on pages 34 to 41.
（発明が解決しようとする課題）
しかしながら、このような従来の後輪舵角制御装置にあ
っては、車速を一定とすると、δｆ／ろ、＝一定となっ
ていたため、定常旋回での安定性は向上するか、緊急回
避的なハンドル操作及びスラローム走行等の動的なハン
ドル操作を行なった場合に、車両の応答性に関しては、
向上代が少ないという問題があった。(Problem to be Solved by the Invention) However, in such a conventional rear wheel steering angle control device, when the vehicle speed is constant, δf/ro = constant, so stability in steady turning is poor. Will the responsiveness of the vehicle improve when performing emergency evasive steering operations and dynamic steering operations such as slalom driving?
The problem was that there was little room for improvement.
そこで、上述の問題を解決する案として、車速およびハ
ンドル操舵角を検出して、前輪舵角ろ、（Ｓ）に対して
後輪舵角ろ、（Ｓ）を次式室を提案した（特願昭６２−
３３０２８３号参照）。Therefore, as a solution to the above problem, we proposed the following formula by detecting the vehicle speed and steering angle and calculating the front wheel steering angle (S) and the rear wheel steering angle (S). Gansho 62-
330283).
しかしながら、この場合、制御定数に、ｔｌ、Ｔ２に含
まれる車両の重心位置と車体の横す”ベリ角をＯとする
位置間の距離β、を、車両重心位置が変動しないと仮定
し、例えば中横時の車両重心位置を基準として一定値に
設定すると、重心位置が車両前方へ移動する空積時には
、オーバステア傾向が強まり操舵応答性か高過ぎて操舵
安定性に欠けてしまうし、また、重心位置が車両後方へ
移動する定積時にはアンダーステア傾向が強まり、操舵
安定性は得られるものの、操舵応答性に欠けるという問
題が残る。However, in this case, assuming that the vehicle center of gravity does not change, the distance β between the position of the center of gravity of the vehicle included in tl and T2 and the position where the lateral angle of the vehicle body is O is included in the control constant, and for example, If the center of gravity of the vehicle is set to a constant value based on the position of the center of gravity when the vehicle is in the middle of the vehicle, when the center of gravity moves toward the front of the vehicle and the vehicle is empty, the oversteer tendency will increase and the steering response will be too high, resulting in a lack of steering stability. At constant volume, where the center of gravity moves toward the rear of the vehicle, the tendency to understeer increases, and although steering stability can be achieved, the problem remains that steering responsiveness is lacking.
尚、特開昭６０−１４８７７２号公報や特開昭６１−１
８５６８号公報には、車両積載荷重により後輪側でのコ
ーナリングパワーを推定し、後輪で発生するコーナリン
グパワーが大きい時には後輪の前輪に対する同相方向転
舵角を増大し、コーナリングパワーを減少させて旋回性
能の向上を図る装置が提案されている。Furthermore, JP-A-60-148772 and JP-A-61-1
No. 8568 discloses that the cornering power at the rear wheels is estimated based on the vehicle load, and when the cornering power generated at the rear wheels is large, the steering angle of the rear wheels in the same phase with respect to the front wheels is increased to reduce the cornering power. A device has been proposed to improve turning performance.
しかし、これらの従来技術の場合には、操舵応答や車両
応答を無視して後輪転舵角の同相補正が行なわれるため
に、後輪転舵角の同相補正時には操舵応答性を変化させ
る前後輪舵角比の急変や車両のヨーレイト特性を変化さ
せるヨーレイト急変が発生し、操舵安定性は得られても
操舵違和感を生じるという問題がある。However, in the case of these conventional technologies, since the in-phase correction of the rear wheel turning angle is performed ignoring the steering response and vehicle response, when the in-phase correction of the rear wheel turning angle is performed, the front and rear wheel steering that changes the steering response is performed. There is a problem in that a sudden change in the angle ratio or a sudden change in the yaw rate that changes the yaw rate characteristics of the vehicle occurs, and even if steering stability is achieved, the steering feels uncomfortable.
（課題を解決するための手段）
上述の問題を解決するため本発明においては、車速及び
ハンドル操舵角を検出して、前輪舵角ろ、 （Ｓ）に対
して後輪舵角δ１（Ｓ）を次式手段を設けると共に、前
記制御手段には、車両重心位置検出手段からの検出信号
に基づいて、車両重心位置が車両後方側へ移る時には車
体横すべり角０点位置を車両前方へ移し、また、車両重
心位置が車両前方側へ移る時には車体横すべり角Ｏ点位
置を車両後方側へ移すことで車両重心位置と車体横すベ
リ角０点位置間の距離β、を車両重心位置移動に応じて
変化させるβ３修正部を有することを特徴とする手段と
した。(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention detects the vehicle speed and steering angle, and calculates the rear wheel steering angle δ1(S) with respect to the front wheel steering angle δ1(S). is provided with a means according to the following formula, and the control means moves the vehicle body sideslip angle 0 point position to the front of the vehicle when the vehicle center of gravity moves to the rear side of the vehicle based on a detection signal from the vehicle center of gravity position detection means; When the vehicle center of gravity moves to the front of the vehicle, the vehicle side slip angle O point position is moved to the rear of the vehicle, thereby changing the distance β between the vehicle center of gravity and the vehicle sideways angle 0 point according to the movement of the vehicle center of gravity. The means is characterized by having a β3 correction section that changes the β3.
尚、前記車両重心位置検出手段としては、前後輪の輪荷
重検出センサを用いてもよい。Note that wheel load detection sensors for the front and rear wheels may be used as the vehicle center of gravity position detection means.
（作 用） 上述のように、本発明によれば、δｆ （Ｓ） ／ろ。(for production) As mentioned above, according to the present invention, δf (S)/ro.
（Ｓ）の伝達関数を１次／１次の形として、車両の模す
へり角が０となる位置を初期位置に設定して後輪制御を
行なうようにしたため、ハンドル操舵に対する車両の応
答性を向上させることができる。The transfer function of (S) is made into a linear/first-order form, and the rear wheel control is performed by setting the position where the vehicle's simulated heel angle is 0 as the initial position, which improves the vehicle's response to steering wheel steering. can be improved.
また、車両重心位置が車両後方側へ移る時には車体横す
ベリ角Ｏ点位置を車両前方へ移し、また、車両重心位置
が車両前方側へ移る時には車体横すべり角０点位置を車
両後方側へ移すことで車両重心位置と車体横すべり角０
点位置間の距離Ｉ２３を車両重心位置移動に応じて変化
させる制御を行なうようにした為、重心位置が車両後方
へ移動する時にはアンダーステア傾向が弱められ、重心
位置が車両前方へ移動する時にはオーバステア傾向が弱
められ、車両重心位置の変化にかかわらず操舵違和感の
ないほぼ一定の操舵安定性と操舵応答性を得ることがで
きる。Also, when the vehicle center of gravity moves to the rear of the vehicle, the vehicle side slip angle O point position is moved to the front of the vehicle, and when the vehicle center of gravity moves to the front of the vehicle, the vehicle side slip angle 0 point position is moved to the rear of the vehicle. As a result, the vehicle center of gravity position and vehicle side slip angle are 0.
Since the distance I23 between the point positions is controlled to change according to the movement of the vehicle center of gravity, the understeer tendency is weakened when the center of gravity moves toward the rear of the vehicle, and the oversteer tendency occurs when the center of gravity moves toward the front of the vehicle. This makes it possible to obtain almost constant steering stability and steering response without any discomfort in steering, regardless of changes in the position of the vehicle center of gravity.
（実施例） 以下、図面について本発明の詳細な説明する。(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.
第１図は本発明の説明用平面図であり、図中１は前輪、
２は後輪、３はステアリングホイール、９は車両の重心
である。また図における各符号は次の通りである。FIG. 1 is an explanatory plan view of the present invention, and in the figure 1 is a front wheel;
2 is the rear wheel, 3 is the steering wheel, and 9 is the center of gravity of the vehicle. Further, each reference numeral in the figure is as follows.
Ｍ：車両重量
工：ヨー慣性モーメント
℃：ホイールベース
ａ：車両の重心と前輪中心間の距離
す二車両の重心と後輪中心間の距離
℃３：車体の重心と車体の横すべり角をＯとする位置間
の距離（後輪方向をプラス
とする）。M: Vehicle weight engineering: Yaw moment of inertia °C: Wheelbase a: Distance between the center of gravity of the vehicle and the center of the front wheels (2) Distance between the center of gravity of the vehicle and the center of the rear wheels °C3: The center of gravity of the vehicle body and the sideslip angle of the vehicle body as O distance between the positions (with the direction of the rear wheels as positive).
Ｆｌ：前輪横力（２輪分）
Ｆ、：後輪横力（２輪分）
Ｃ１：前輪のコーナリングパワー（２輪分）Ｃ２：後輪
のコーナリングパワー（２輪分）β１：前輪タイヤの横
すべり角
β２：後輪タイヤの模すベリ角
Ｖ二車速。Fl: Front wheel lateral force (2 wheels) F,: Rear wheel lateral force (2 wheels) C1: Front wheel cornering power (2 wheels) C2: Rear wheel cornering power (2 wheels) β1: Front wheel lateral force (2 wheels) Side slip angle β2: Belly angle imitated by rear tires V2 Vehicle speed.
Ｖ：横移動速度
ω：ヨーレイト
Ｎニステアリングギヤ比
第１図に示す線型２自由度モデルにおいて、運動方程式
をラプラス変換した形で表わすと、ここで、６１＝θ／
Ｎ （前輪操舵角）、ろ、を後輪操舵角とすると、
いま重心点後方ｆ２３の距離での横移動速度をｖ３とす
ると、
ｖ３＝ｖ−β３ω ・・・・■で表わさ
れる。V: Lateral movement speed ω: Yaw rate N Steering gear ratio In the linear two-degree-of-freedom model shown in Figure 1, the equation of motion is expressed in Laplace transformed form, where 61 = θ/
If N (front wheel steering angle) and b are the rear wheel steering angles, and if the lateral movement speed at a distance f23 behind the center of gravity is v3, it is expressed as v3=v-β3ω...■.
ここで１２３の位置で横移動速度ｖ３が０となるように
、後輪を操舵する時の後輪操舵制御関数を求める。Here, a rear wheel steering control function for steering the rear wheels is determined so that the lateral movement speed v3 becomes 0 at position 123.
ｖ３＝０より
Ｖ＝β３ω ・・・・■となる、こ
れを前述の■〜■に代入すると、前輪舵角δｆに応動じ
て後輪舵角δｆをδ２（Ｓ）＝Ｇ（Ｓ）・δｆ （Ｓ）
となる伝達関数Ｇ （Ｓ）によって制御を行なう場合
に、上述の式を用いてＧ （Ｓ）を求めることができ
る。From v3=0, V=β3ω...■. Substituting this into the above-mentioned ■~■, the rear wheel steering angle δf is changed in response to the front wheel steering angle δf as δ2(S)=G(S)・δf (S)
When performing control using the transfer function G (S), G (S) can be obtained using the above equation.
ω、６１でまとめ直して、 の関数式が得られる。Regroup at ω, 61, The functional formula is obtained.
左側の項（）内をそれぞれＡ、ＢとしてＧを求めると、
（ａ Ｃ，−ｂ Ｃ２Ｇ ）Ａ ＝ （Ｃ，＋Ｃ，Ｇ）
Ｂここで、
Ｇの分子＝ａ Ｃ＋Ａ −ＣＡＢ
ω １ ω
θ Ｎ δ
Ｇの分母＝ｂ Ｃ２Ａ ＋Ｃ，Ｂ
従って、
とすれば、■式は下記のようになる。If we calculate G by setting the terms () on the left as A and B, we get (a C, -b C2G) A = (C, +C, G)
BHere, numerator of G=a C+A −CAB ω 1 ω θ N δ Denominator of G=b C2A +C,B Therefore, if it is set, then the equation (2) becomes as follows.
・・・・■
ハンドル操舵角に対するヨーレイト特性は、従って本発
明においては、車速およびハンドル操舵角を検出して、
前輪舵角δｆ（Ｓ）に対して後輪舵角δｒ （Ｓ）を次
式
に基づいて制御すると共に、車両重心位置が車両後方側
へ移る時には車体横すベリ角０点位置を車両前方へ移し
、また、車両重心位置が車両前方側へ移る時には車体横
すべり角０点位置を車両後方側へ移すことで車両重心位
置と車体横すベリ角０点位置間の距離Ｉ２３を車両重心
位置移動に応じて変化させる制御がおこなわれる。...■ Therefore, in the present invention, the yaw rate characteristic with respect to the steering wheel steering angle is determined by detecting the vehicle speed and the steering wheel steering angle.
The rear wheel steering angle δr (S) is controlled with respect to the front wheel steering angle δf (S) based on the following formula, and when the vehicle center of gravity moves to the rear of the vehicle, the 0 point position of the vehicle horizontal belly angle is moved to the front of the vehicle. Also, when the vehicle center of gravity moves to the front side of the vehicle, the vehicle body side slip angle 0 point position is moved to the vehicle rear side, thereby changing the distance I23 between the vehicle center of gravity position and the vehicle body side slip angle 0 point position to move the vehicle center of gravity position. Control is performed to change it accordingly.
第２図及び第３図は本発明を実施する車両およびその制
御装置の一例を示すものである。図中＋Ｌ、ＩＲは夫々
左右前輪、２Ｌ、２Ｒは夫々左右後輪である。前輪ＩＬ
、ＩＲを夫々ステアリングホイール３によりステアリン
グギヤ４を介して転舵可能とし、前輪舵角δｆはステア
リングホイル操舵角をθ、ステアリングギヤ比をＮとす
ると、ろ、＝θ／Ｎで表わされる。トランスバースリン
ク５Ｌ、５Ｒ及びアッパアーム６Ｌ、６Ｒを含むリヤサ
スペンション装置により車体のりャサスペンションメン
バ７に懸架された後輪２Ｌ。FIGS. 2 and 3 show an example of a vehicle and its control device implementing the present invention. In the figure, +L and IR are the left and right front wheels, respectively, and 2L and 2R are the left and right rear wheels, respectively. Front wheel IL
, IR can be steered by the steering wheel 3 via the steering gear 4, and the front wheel steering angle δf is expressed as θ=θ/N, where θ is the steering wheel steering angle and N is the steering gear ratio. A rear wheel 2L is suspended on a vehicle suspension member 7 by a rear suspension device including transverse links 5L, 5R and upper arms 6L, 6R.
２日も転舵可能とし、この目的のため、後輪のナックル
アーム８ｍ、ＢＲ間をアクチュータ９およびその両端に
おけるサイドロッド＋ＯＬ、４０Ｒにより相互に連結す
る。It is possible to steer the vehicle even on two days, and for this purpose, the rear wheel knuckle arm 8m and BR are interconnected by an actuator 9 and side rods +OL and 40R at both ends thereof.
アクチュエータ９はスプリングセンタ式復動液圧シリン
ダとし、その２室を夫々管路１１Ｌ、１１Ｒにより電磁
比例式圧力制御弁１２に接続する。この制御弁１２には
更にポンプ１３及びリザーバタンク１４を含む液圧源の
液圧管路１５及びドレン管路１６を夫々接続する。制御
弁１２はスプリングセンタ式３位置弁とし、両ソレノイ
ド１２Ｌ、１２ＲのＯＦＦ時管路１１Ｌ、１１Ｒを無圧
状態にし、ソレノイド１２ＬのＯＮＮ連通電量比例した
圧力を管路１１Ｌに供給し、ソレノイド１２ＲのＯＮＮ
連通電量比例した圧力を管路１１Ｒに供給するものとす
る。The actuator 9 is a spring center double-acting hydraulic cylinder, and its two chambers are connected to an electromagnetic proportional pressure control valve 12 through pipes 11L and 11R, respectively. The control valve 12 is further connected to a hydraulic pressure line 15 and a drain line 16 of a hydraulic pressure source including a pump 13 and a reservoir tank 14, respectively. The control valve 12 is a spring center type 3-position valve, and when both solenoids 12L and 12R are OFF, the pipes 11L and 11R are in a pressureless state, and a pressure proportional to the ON/N energization amount of the solenoid 12L is supplied to the pipe 11L, and the solenoid 12R is turned off. ONN of
It is assumed that a pressure proportional to the amount of communication current is supplied to the conduit 11R.
ソレノイド１２Ｌ、１２ＲのＯＮ、 ＯＦＦ及び通電量
はコントローラ１アにより電子制御し、このコントロー
ラ１７は第３図に示す如くデジタル演算回路１７ａと、
デジタル入力検出回路１７ｂと、記憶回路１７ｃと、Ｄ
／Ａ変換器１７ｄと、駆動回路１７ｅと、Ａ／Ｄ変換器
１７ｆとで構成する。The ON/OFF and energization amounts of the solenoids 12L and 12R are electronically controlled by a controller 1a, and this controller 17 has a digital calculation circuit 17a as shown in FIG.
Digital input detection circuit 17b, storage circuit 17c, and D
It is composed of an /A converter 17d, a drive circuit 17e, and an A/D converter 17f.
前記コントローラ１７には、ステアリングホイール３の
操舵角θを検出する操舵角センサ１８からの信号と、車
速を検出する車速センサ１９からの信号とを夫々デジタ
ル入力検出回路１７ｂを経て入力すると共に、各輪ＩＬ
、ＩＲ，２Ｌ、２Ｒのサスペンションに設けられた輪荷
重センサ２０（例えば、圧電タイプ）からのアナログ信
号をＡ／Ｄ変換器１７ｆを経て入力する。A signal from a steering angle sensor 18 that detects the steering angle θ of the steering wheel 3 and a signal from a vehicle speed sensor 19 that detects the vehicle speed are input to the controller 17 via a digital input detection circuit 17b, respectively. Ring IL
, IR, 2L, and 2R suspensions are input with analog signals from wheel load sensors 20 (for example, piezoelectric type) through an A/D converter 17f.
コントローラ１７のデジタル演算回路１７ａはこれら入
力情報及び記憶回路１７ｃの格納定数を基に前記０式を
演算し、演算結果に対応した後輪舵角δｆに関するデジ
タル信号をＤ／Ａ変換器１７ｄによりアナログ信号に変
換する。このアナログ信号は駆動回路１７ｅにより後輪
舵角ろ、に対応した電流ｉに変換され、制御弁１２に供
給される。The digital calculation circuit 17a of the controller 17 calculates the above equation 0 based on the input information and the storage constant of the storage circuit 17c, and converts the digital signal related to the rear wheel steering angle δf corresponding to the calculation result into an analog signal using the D/A converter 17d. Convert to signal. This analog signal is converted by the drive circuit 17e into a current i corresponding to the rear wheel steering angle, and is supplied to the control valve 12.
この際コントローラ１７は制御弁１２のいずれのソレノ
イド＋２Ｌ又は＋２Ｒに電流ｉを供給すべきかを操舵角
θから決定し、対応する管路ＭＬ又は＋ＩＲ１，：電流
ｉ（演算後輪舵角δｆ）に応じだ液圧を発生させる。ア
クチュエータ９はこの液圧に応じた方向へ又この液圧に
応じた距離だけストロークし、サイドロッドＩＯＬ及び
＋ＯＲを介し後輪２Ｌ及び２日を対応方向へ演算結果に
応じた角度だけ転舵することができる。At this time, the controller 17 determines which solenoid +2L or +2R of the control valve 12 should be supplied with the current i from the steering angle θ, and applies the current i (calculated rear wheel steering angle δf) to the corresponding conduit ML or +IR1. Generates corresponding hydraulic pressure. The actuator 9 strokes in a direction according to this hydraulic pressure and by a distance according to this hydraulic pressure, and steers the rear wheels 2L and 2 in the corresponding direction by an angle according to the calculation result via the side rods IOL and +OR. be able to.
次に作用を説明する。Next, the action will be explained.
まず、コントローラ］Ｙの演算回路１７ａでは、輪荷重
センサ２０からの信号により車速毎の制御定数に、 Ｔ
Ｉ、 Ｔ２を演算し、これを記憶回路１７Ｃの中にマツ
プ化して入れておく。そして、操舵角と車速の両センサ
１８，１９からの信号により後輪舵角６．を演算し、後
輪舵角δｆに応じた電流ｉを駆動回路１７ｅを通じて圧
力制御弁１２に送る。First, in the arithmetic circuit 17a of the controller Y, the control constant for each vehicle speed is determined by the signal from the wheel load sensor 20.
I and T2 are calculated and stored as a map in the memory circuit 17C. Then, based on the signals from both the steering angle and vehicle speed sensors 18 and 19, the rear wheel steering angle 6. is calculated, and a current i corresponding to the rear wheel steering angle δf is sent to the pressure control valve 12 through the drive circuit 17e.
この制御作動流れを第４図及び第５図のフローチャート
図に示す。The flow of this control operation is shown in the flow charts of FIGS. 4 and 5.
即ち、第４図のサブルーチンの流れに示すように、制御
定数の演算処理は、車両が停止状態のとき、イグニッシ
ョンスイッチをＯＮとすると、輪荷重センサ２０からの
情報を取り込み、制御定数に、 ＴＩ、 Ｔ２に必要な
車両諸元値の演算及び車速毎（例えば、車両総元値の演
算の及び車両毎（例えば、２〜４ ｋｍ／ｈピッチ）の
制御定数に、 ＴＩ、 Ｔ２を演算してその結果を記憶
する。That is, as shown in the flow of the subroutine in FIG. 4, the control constant calculation process is such that when the ignition switch is turned on when the vehicle is stopped, information from the wheel load sensor 20 is taken in, and the control constant is set to TI. , Calculate TI and T2 for the calculation of vehicle specification values required for T2 and the control constants for each vehicle speed (for example, calculation of the total vehicle original value and for each vehicle (for example, 2 to 4 km/h pitch)) Memorize the result.
そして、車両が動き始めると、第５図のメインルーチン
の流れに示すように操舵角センサ１７及び車速センサ１
８からの信号を受けて所定時間毎に後輪舵角６．が演算
され、その後輪舵角ろ、に応じた制御電流ｉが駆動回路
１７ｅを通じて圧力制御弁１２に送られる。When the vehicle starts moving, the steering angle sensor 17 and the vehicle speed sensor 1 are
The rear wheel steering angle is adjusted every predetermined time in response to the signal from 6. is calculated, and a control current i corresponding to the rear wheel steering angle is sent to the pressure control valve 12 through the drive circuit 17e.
次に、−船内な乗用車の車両諸元を用いてに。Next, - using the vehicle specifications of a passenger car on board.
ＴＩ、 Ｔ２を計算すると第６図のようになる。この図
表では、車体の横すベリ角０の位置を、後輪位置（β３
＝ｂ）、車両重心点位置（β、＝Ｏ）、前輪位置（β３
＝ａ）とした時のそれぞれのに、■＋、Ｔ２の曲線を示
している。Calculating TI and T2 results in the results shown in Figure 6. In this diagram, the position of the vehicle body's lateral belly angle of 0 is defined as the rear wheel position (β3
=b), vehicle center of gravity position (β, =O), front wheel position (β3
The curves of ■+ and T2 are shown for each case when =a).
又ハンドル操舵角に対する車両のヨーレイト周波数特性
を求めると第７図のようになる。この図から制御なしの
２ＷＳ車に比べて本発明に係る４ＷＳ車はヨーレイトゲ
インの静動比が小さく、ヨーのダンピングかよいことが
判る。The yaw rate frequency characteristic of the vehicle with respect to the steering angle is determined as shown in FIG. 7. From this figure, it can be seen that the 4WS vehicle according to the present invention has a smaller static-dynamic ratio of yaw rate gain and better yaw damping than the 2WS vehicle without control.
前記［相］式でも明らかなように、ヨーレイト／ハンド
ル角の伝達関数は１次遅れ形となり、通常２ＷＳのよう
に１次進み＋２次振動形を構成しない。As is clear from the above [phase] equation, the transfer function of yaw rate/steering wheel angle is a first-order lag type, and does not usually constitute a first-order lead + second-order vibration type like the 2WS.
すなわち、車線変更等でハンドルを戻した直後に車のヨ
ーレイトがオーバーシュートすることがない。In other words, the yaw rate of the vehicle will not overshoot immediately after the steering wheel is turned back to change lanes or the like.
さらにヨーレイトの位相遅れが小さく、高周波数域まで
ゲイン、位相遅れ共低下が少ないことから、ハンドル操
舵に対して車両の応答性も良いことがわかる。Furthermore, the yaw rate phase lag is small, and both gain and phase lag decrease little in the high frequency range, indicating that the vehicle has good responsiveness to steering wheel steering.
また、β３を変えることにより、車両の運動性能を変え
ることができ、ρ３を後輪位置近傍にすると、安定性の
高い車両特性となり、前輪近傍とすると特に低速時にお
ける機敏性が増す車両特性となる。このことは車両の性
格に応じて自由に車両特性を変えられる設計的自由度を
持つことを意味する。In addition, by changing β3, the dynamic performance of the vehicle can be changed. Setting ρ3 near the rear wheels will result in vehicle characteristics with high stability, while setting ρ3 near the front wheels will result in vehicle characteristics that increase agility, especially at low speeds. Become. This means that there is a degree of design freedom in which vehicle characteristics can be changed freely according to the characteristics of the vehicle.
但し、β、＞ｂとすると、安定性が過大となると共に、
機敏性かなくなり、Ｉ３〈−ａとすると、その逆の結果
となる。従って２３は−ａ〈、Ｑ ３＜ｂの範囲で決定
することが必要である。However, if β>b, the stability becomes excessive and
If the agility is lost and I3<-a, the opposite result will occur. Therefore, it is necessary to determine 23 within the range of -a<, Q3<b.
また第８図は、本発明の６．（Ｓ）／δｆ （Ｓ）の周
波数応答特性を示すものである。FIG. 8 also shows 6. of the present invention. It shows the frequency response characteristic of (S)/δf (S).
第９図は、定常ヨーレイトゲインの車速依存性を示すも
のである。FIG. 9 shows the dependence of steady yaw rate gain on vehicle speed.
そこで、本実施例では、車両積載荷重等の変化による車
両重心位置の移動に応じて最適な車両運動性能が得られ
るように２３を変化させるようにしている。Therefore, in this embodiment, 23 is changed so as to obtain the optimum vehicle motion performance in accordance with the movement of the vehicle center of gravity position due to changes in the vehicle carrying load, etc.
即ち、輪荷重センサ２０からの検出信号に基づいて車両
重心位置を判断し、第１０図の特性に示すように、例え
ば、重心位置が後方に下がるとアンダーステア傾向が強
くなるために、これを弱めるべくＩ３を前方向（−）に
とるような制御を行なう。重心位置が前方にくる時には
、オーバステア傾向が強くなるために、これを弱めるべ
くＩ２３を後方向（＋）にとるような制御を行なう。That is, the position of the center of gravity of the vehicle is determined based on the detection signal from the wheel load sensor 20, and as shown in the characteristics of FIG. Control is performed to move I3 in the forward direction (-) as much as possible. When the center of gravity is located forward, the oversteer tendency becomes strong, so control is performed to move I23 backward (+) in order to weaken this tendency.
従って、中積状態から定積状態とする場合等で車両重心
位置が後方に下がった場合には、Ｉ２３が前方向（−）
にとられるために、第６図〜第９図に示すように、応答
性（機敏性）が増し、車両重心位置が後方に下がること
による応答性の低下が２３の変更により抑えられ、最適
の応答性を得ることができる。Therefore, if the center of gravity of the vehicle drops to the rear, such as when changing from a middle load state to a constant load state, I23 will move forward (-).
As shown in Figures 6 to 9, the responsiveness (agility) increases, and the decrease in responsiveness due to the vehicle's center of gravity moving backwards is suppressed by changing 23, resulting in the optimal You can get responsiveness.
また、中積状態から空車状態とする場合等で車両重心位
置が前方にくる場合には、β３が後方向（＋）にとられ
るために、第６図〜第９図に示すように、安定性が増し
、車両重心位置が前方にくることによる安定性の低下か
Ｉ３の変更により抑えられ、最適の安定性を得ることが
できる即ち、車両重心位置の変化による応答性及び安定
性の変化をＩ３の変更により抑えられることになり、車
両重心位置の変化にかかわらず、操舵違和感のないほぼ
一定の応答性及び安定性を得ることができる。In addition, when the center of gravity of the vehicle moves to the front, such as when changing from a partially loaded state to an empty state, β3 is taken toward the rear (+), resulting in stability, as shown in Figures 6 to 9. The decrease in stability due to the vehicle's center of gravity moving forward can be suppressed by changing I3, and optimal stability can be obtained.In other words, changes in responsiveness and stability due to changes in the vehicle's center of gravity can be suppressed. This can be suppressed by changing I3, and it is possible to obtain almost constant responsiveness and stability without any discomfort in steering, regardless of changes in the position of the center of gravity of the vehicle.
以上、本発明の実施例を図面により説明してきたが、具
体的な構成等は実施例に限られるものではなく、例えば
、車両重心位置検出手段として、輪荷重センサの例を示
したが、乗員数や積載量等でドライバー等が重心位置を
スイッチ操作で設定する手段や、重心位置の変化により
影響する車両運動の監視により重心位置を推定する手段
等を用いても良い。Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration etc. are not limited to the embodiments. It is also possible to use a method in which the driver or the like sets the center of gravity position by operating a switch based on the number or load, or a means to estimate the center of gravity position by monitoring vehicle motion that is affected by changes in the center of gravity position.
（発明の効果）
以上説明してきたように、本発明の後輪舵角制御装置に
よれば、ろ、 ＜Ｓ）／ろｆ（Ｓ）の伝達関数を１次／
１次の形として、車体の横すべり角が０となる位置を初
期位置に設定して後輪制御を行なうようにしたため、ハ
ンドル操舵に対する車両の応答性を向上させることがで
きる。(Effects of the Invention) As explained above, according to the rear wheel steering angle control device of the present invention, the transfer function of f(S)
As a first order form, the rear wheel control is performed by setting the position where the sideslip angle of the vehicle body is 0 as the initial position, so that the responsiveness of the vehicle to steering wheel steering can be improved.
また、車両重心位置が車両後方側へ移る時には車体横す
べり角０点位置を車両前方へ移し、また、車両重心位置
が車両前方側へ移る時には車体横すベリ角０点位置を車
両後方側へ移すことで車両重心位置と車体横すべり角Ｏ
点位置間の距離β、を車両重心位置移動に応じて変化さ
せるようにしたため、車両重心位置の変化にかかわらず
操舵違和感のないほぼ一定の操舵安定性と操舵応答性を
得ることができる。Also, when the center of gravity of the vehicle moves to the rear of the vehicle, the zero point position of the vehicle side slip angle is moved to the front of the vehicle, and when the center of gravity of the vehicle moves to the front of the vehicle, the zero point position of the vehicle side slip angle is moved to the rear of the vehicle. Therefore, the position of the vehicle center of gravity and the vehicle sideslip angle O
Since the distance β between the point positions is changed in accordance with the movement of the center of gravity of the vehicle, it is possible to obtain substantially constant steering stability and steering response without causing any discomfort in steering, regardless of changes in the position of the center of gravity of the vehicle.
第１図は本発明の説明用平面図、第２図は本発明を適用
する車両の制御装置図、第３図はその制御装置のブロッ
ク線図、第４図及び第５図は実施例装置のコントローラ
での制御処理作動の流れを示すフローチャート図、第６
図〜第９図は本発明の説明用の各種特性図、第１０図は
車両重心位置の変化にに対するβ１位置の設定特性図で
ある。
１、 ＋Ｌ、 ＩＦ＋・・・前輪 ２．２ Ｌ、２Ｒ・
・・後輪３・・・ステアリングホイール
４・・・ステアリングギヤ
５Ｌ、５Ｒ・・−トランスバースリンク６Ｌ、６Ｒ・・
・アッパアーム
７・・・リャサスペンションメンバ
９・・・アクチュエータ
２・・・電磁比例式圧力制御弁
７・・・コントローラ
８・・・操舵角センサ
９・・・車速センサ
０・・・輪荷重センサFIG. 1 is a plan view for explaining the present invention, FIG. 2 is a diagram of a control device of a vehicle to which the present invention is applied, FIG. 3 is a block diagram of the control device, and FIGS. 4 and 5 are an embodiment of the device. Flowchart diagram showing the flow of control processing operation in the controller, No. 6
9 to 9 are various characteristic diagrams for explaining the present invention, and FIG. 10 is a setting characteristic diagram of the β1 position with respect to changes in the position of the center of gravity of the vehicle. 1, +L, IF+...Front wheel 2.2 L, 2R・
... Rear wheel 3 ... Steering wheel 4 ... Steering gear 5L, 5R ... - Transverse link 6L, 6R ...
- Upper arm 7... Rear suspension member 9... Actuator 2... Electromagnetic proportional pressure control valve 7... Controller 8... Steering angle sensor 9... Vehicle speed sensor 0... Wheel load sensor
Claims (1)
速およびハンドル操舵角を検出して、前輪舵角δ＿ｆ（
Ｓ）に対して後輪舵角δ＿ｒ（Ｓ）を次式δ＿ｒ（Ｓ）
／δ＿ｆ（Ｓ）＝（Ｋ＋Ｔ１・Ｓ）／（１＋Ｔ２・Ｓ）
但し、 Ｓ：ラプラス演算子 Ｋ、Ｔ１、Ｔ２：制御定数 Ｋ＝Ｃ＿１｛ａＭＶ＾２＋Ｃ＿２ｌ（ｌ＿３−ｂ）｝／
Ｃ＿２｛ｂＭＶ＾２＋Ｃ＿１ｌ（ｌ＿３−ａ）｝Ｔ１＝
Ｃ＿１Ｖ（ａＭｌ＿３−Ｉ）／Ｃ＿２｛ｂＭＶ＾２＋Ｃ
＿１ｌ（ｌ＿３−ａ）｝Ｔ２＝Ｖ（ｂＭｌ＿３＋Ｉ）／
｛ｂＭＶ＾２＋Ｃ＿１ｌ（ｌ＿３＋ａ）｝ Ｍ：車両重量 Ｉ：ヨー慣性モーメント ｌ：ホィールベース ａ：車両の重心と前輪中心間の距離 ｂ：車両の重心と後輪中心間の距離 ｌ＿３：車体の重心と車体の横すべり角を０とする位置
間の距離（後輪方向をプラス とする）。 Ｃ＿１：前輪のコーナリングパワー（２輪分） Ｃ＿２：後輪のコーナリングパワー（２輪分） Ｖ：車速。 に基づいて制御する制御手段を設けると共に、前記制御
手段には、車両重心位置検出手段からの検出信号に基づ
いて、車両重心位置が車両後方側へ移る時には車体横す
べり角０点位置を車両前方へ移し、また、車両重心位置
が車両前方側へ移る時には車体横すべり角０点位置を車
両後方側へ移すことで車両重心位置と車体横すべり角０
点位置間の距離ｌ＿３を車両重心位置移動に応じて変化
させるｌ＿３修正部を有することを特徴とする後輪舵角
制御装置。 ２）前記車両重心位置検出手段が、前後輪の輪荷重検出
センサである請求項１記載の後輪舵角制御装置。[Claims] 1) The vehicle speed and the steering wheel steering angle are detected by the vehicle speed detecting means and the steering wheel steering angle detecting means, and the front wheel steering angle δ_f(
The rear wheel steering angle δ_r(S) for S) is calculated using the following formula δ_r(S)
/δ_f(S)=(K+T1・S)/(1+T2・S)
However, S: Laplace operator K, T1, T2: control constant K=C_1{aMV^2+C_2l(l_3-b)}/
C_2{bMV^2+C_1l(l_3-a)}T1=
C_1V(aMl_3-I)/C_2{bMV^2+C
_1l(l_3-a)}T2=V(bMl_3+I)/
{bMV＾2+C_1l(l_3+a)} M: Vehicle weight I: Yaw moment of inertia l: Wheelbase a: Distance between the center of gravity of the vehicle and the center of the front wheels b: Distance between the center of gravity of the vehicle and the center of the rear wheels l_3: Between the center of gravity of the vehicle body Distance between positions where the side slip angle of the vehicle body is 0 (rear wheel direction is positive). C_1: Front wheel cornering power (2 wheels) C_2: Rear wheel cornering power (2 wheels) V: Vehicle speed. The control means is provided with a control means for controlling based on the detection signal from the vehicle center of gravity position detection means, and the control means is configured to move the vehicle body sideslip angle 0 point position toward the front of the vehicle when the vehicle center of gravity position moves to the rear side of the vehicle. Also, when the vehicle center of gravity moves to the front of the vehicle, the vehicle body sideslip angle 0 point position is moved to the rear of the vehicle, thereby changing the vehicle center of gravity and vehicle sideslip angle 0.
A rear wheel steering angle control device comprising an l_3 correction section that changes a distance l_3 between point positions in accordance with movement of the vehicle center of gravity. 2) The rear wheel steering angle control device according to claim 1, wherein the vehicle center of gravity position detection means is a wheel load detection sensor for the front and rear wheels.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22688588A JPH0274471A (en) | 1988-09-10 | 1988-09-10 | Rear wheel steering angle control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22688588A JPH0274471A (en) | 1988-09-10 | 1988-09-10 | Rear wheel steering angle control device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0274471A true JPH0274471A (en) | 1990-03-14 |
Family
ID=16852107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22688588A Pending JPH0274471A (en) | 1988-09-10 | 1988-09-10 | Rear wheel steering angle control device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0274471A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003048565A (en) * | 2001-08-07 | 2003-02-18 | Koyo Seiko Co Ltd | Vehicular steering system |
| JP2006335171A (en) * | 2005-06-01 | 2006-12-14 | Toyota Motor Corp | Driving/braking force control device for vehicle |
-
1988
- 1988-09-10 JP JP22688588A patent/JPH0274471A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003048565A (en) * | 2001-08-07 | 2003-02-18 | Koyo Seiko Co Ltd | Vehicular steering system |
| JP2006335171A (en) * | 2005-06-01 | 2006-12-14 | Toyota Motor Corp | Driving/braking force control device for vehicle |
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