JP2577436B2 - Steering control device for front and rear wheel steering vehicles - Google Patents

Steering control device for front and rear wheel steering vehicles

Info

Publication number
JP2577436B2
JP2577436B2 JP14536288A JP14536288A JP2577436B2 JP 2577436 B2 JP2577436 B2 JP 2577436B2 JP 14536288 A JP14536288 A JP 14536288A JP 14536288 A JP14536288 A JP 14536288A JP 2577436 B2 JP2577436 B2 JP 2577436B2
Authority
JP
Japan
Prior art keywords
steering
rear wheel
steering angle
wheel
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.)
Expired - Fee Related
Application number
JP14536288A
Other languages
Japanese (ja)
Other versions
JPH01314670A (en
Inventor
修 鶴宮
将隆 伊澤
賢 阿部
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Honda Motor Co Ltd
Original Assignee
Honda Motor Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Honda Motor Co Ltd filed Critical Honda Motor Co Ltd
Priority to JP14536288A priority Critical patent/JP2577436B2/en
Priority to US07/226,070 priority patent/US4939653A/en
Priority to FR8810305A priority patent/FR2620674B1/en
Priority to GB8818071A priority patent/GB2208375B/en
Priority to DE3825885A priority patent/DE3825885A1/en
Publication of JPH01314670A publication Critical patent/JPH01314670A/en
Application granted granted Critical
Publication of JP2577436B2 publication Critical patent/JP2577436B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

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
    • 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
    • B62D7/148—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 provided with safety devices
    • 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
    • B62D7/1581—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 comprising an electrical interconnecting system between the steering control means of the different axles

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)

Description

【発明の詳細な説明】 （産業上の利用分野） この発明は後輪をも転舵する前後輪操舵車両の操舵制
御装置に係り、詳しくは、後輪の操舵力を前輪の舵角の
時間的変化に応じ制御して旋回特性の向上を図る操舵制
御装置に関する。Description: BACKGROUND OF THE INVENTION The present invention relates to a steering control device for a front-rear-wheel steering vehicle that also turns a rear wheel, and more particularly, to a method of controlling the steering force of a rear wheel to the time of the steering angle of a front wheel. The present invention relates to a steering control device for controlling a turning characteristic to improve the turning characteristic.

（従来の技術） 前輪とともに後輪も転舵する前後輪操舵車両にあって
は、一般に、前後輪の舵角比および位相を車速に応じ制
御して操縦性能の向上が図られる。このような前後輪操
舵車両は、低車速域において後輪を前輪と逆方向（逆位
相）に転舵させて旋回半径の小径化（回頭性の向上）を
図り、また、高車速域において後輪を前輪と同方向（同
位相）に転舵させて安定性の向上を図る。(Prior Art) In a front-rear-wheel steering vehicle in which a rear wheel is steered as well as a front wheel, generally, a steering angle ratio and a phase of the front and rear wheels are controlled according to a vehicle speed to improve steering performance. In such a front-rear-wheel steering vehicle, the rear wheel is steered in the opposite direction (opposite phase) to the front wheel in a low vehicle speed range to reduce the turning radius (improve turning performance), and in a high vehicle speed range. The wheels are steered in the same direction (the same phase) as the front wheels to improve stability.

従来、この種の前後輪操舵車両の操舵制御装置は、特
開昭60−67272号公報に記載されたようなものが知られ
ている。この特開昭60−67272号公報に記載された操舵
制御装置は、パルスモータに操舵速度に応じたステップ
角のパルス信号を出力してパルスモータにより後輪を転
舵し、後輪を操舵速度に応じた特性でモータを応答さ
せ、モータの追従性を向上させんとする。2. Description of the Related Art Conventionally, a steering control apparatus for a front-rear-wheel steering vehicle of this type is disclosed in Japanese Patent Application Laid-Open No. 60-67272. The steering control device described in Japanese Patent Application Laid-Open No. 60-67272 outputs a pulse signal having a step angle corresponding to the steering speed to a pulse motor, turns the rear wheel by the pulse motor, and drives the rear wheel at the steering speed. The motor is made to respond with the characteristic according to the above, and the followability of the motor is improved.

（この発明が解決しようとする課題） しかしながら、上述の特開昭60−67272号公報の操舵
制御装置にあっては、ステップモータの出力トルクは一
定で、また、ステップモータの出力軸の回転角と後輪の
転舵角とが所定の比率で対応して後輪の転舵角速度もス
テップモータの出力軸の回転速度に応じ一義的に決定さ
れる。このため、このような操舵制御装置は、走行路面
の摩擦係数を考慮しておらず、後輪は常に目標角度に転
舵されて、路面状態に応じた旋回特性は得られないとい
う問題点があった。(Problems to be Solved by the Invention) However, in the steering control device disclosed in Japanese Patent Laid-Open No. 60-67272, the output torque of the step motor is constant, and the rotation angle of the output shaft of the step motor is fixed. And the steering angle of the rear wheel correspond at a predetermined ratio, and the steering angular speed of the rear wheel is also uniquely determined according to the rotation speed of the output shaft of the step motor. For this reason, such a steering control device does not consider the friction coefficient of the traveling road surface, and the rear wheels are always steered to the target angle, and the turning characteristic according to the road surface condition cannot be obtained. there were.

一方、上述のような問題点を解決するには、後輪の転
舵角速度を走行路面の摩擦係数に応じて制御することも
考えられるが、走行路面の摩擦係数を検出するセンサ等
が不可欠で製造コストの増大を招くという問題点があ
る。On the other hand, in order to solve the above problems, it is conceivable to control the turning angular velocity of the rear wheels according to the friction coefficient of the traveling road surface, but a sensor or the like for detecting the friction coefficient of the traveling road surface is indispensable. There is a problem that the manufacturing cost is increased.

この発明は、上述の問題点に鑑みてなされたもので、
センサ等を用いること無く後輪の転舵角速度が走行路面
の摩擦係数に応答する操舵制御装置を提供することを目
的とする。The present invention has been made in view of the above problems,
It is an object of the present invention to provide a steering control device in which a turning angular velocity of a rear wheel responds to a friction coefficient of a traveling road surface without using a sensor or the like.

（課題を解決するための手段） この発明にかかる前後輪操舵車両の操舵制御装置は、
第１図の構成図に示すように、操向ハンドルの操舵に応
じ前輪とともに後輪を転舵する前後輪操舵車両におい
て、前輪の転舵角度を検出する前輪舵角検知手段と、後
輪の転舵角度を検出する後輪舵角検知手段と、車速を検
出する車速検知手段と、該車速検知手段により検出され
た車速および前記前輪舵角検知手段により検出された前
輪の転舵角度に応じて後輪の目標転舵角度を決定する後
輪目標舵角決定手段と、該後輪目標舵角決定手段により
決定された後輪の目標転舵角度と前記後輪舵角検知手段
により検出された後輪の転舵角度との偏差に応じて後輪
の目標操舵力を決定する後輪操舵力決定手段と、前輪の
転舵角度の時間的変化を検出する前輪操舵速度検知手段
と、該操舵速度検知手段により検出された時間的変化に
応じて前記後輪操舵力決定手段により決定された目標操
舵力を前記時間的変化が大きい場合に小さくなるように
補正する操舵力補正手段と、該操舵力補正手段により補
正された目標操舵力で後輪を目標転舵角度に転舵する駆
動手段と、を備えることが要旨である。(Means for Solving the Problems) A steering control device for a front and rear wheel steering vehicle according to the present invention includes:
As shown in the configuration diagram of FIG. 1, in a front and rear wheel steering vehicle that steers a rear wheel together with a front wheel in response to steering of a steering wheel, front wheel steering angle detecting means for detecting a steering angle of a front wheel, A rear wheel steering angle detecting means for detecting a steering angle, a vehicle speed detecting means for detecting a vehicle speed, and a vehicle speed detected by the vehicle speed detecting means and a steering angle of a front wheel detected by the front wheel steering angle detecting means. A rear wheel target steering angle determining means for determining a target steering angle of the rear wheel, a target steering angle of the rear wheel determined by the rear wheel target steering angle determining means and the rear wheel steering angle detecting means detecting the target steering angle. Rear wheel steering force determining means for determining a target steering force of the rear wheel according to a deviation from the rear wheel steering angle, front wheel steering speed detecting means for detecting a temporal change in the front wheel steering angle, and The rear wheel steering is performed according to a temporal change detected by a steering speed detecting unit. Steering force correction means for correcting the target steering force determined by the determination means so as to be smaller when the temporal change is large; and a target steering angle of the rear wheels with the target steering force corrected by the steering force correction means. And a driving means for turning the steering wheel.

（作用） この発明にかかる前後輪操舵車両の操舵制御装置によ
れば、後輪の転舵角度の時間的変化は走行路面の摩擦係
数とほぼ対応して起こり、決定された後輪の目標操舵力
を前輪の転舵角度の時間的変化に応じ該時間的変化が大
きい場合に小さくなるように補正するため、通常の操舵
速度において、安定性の向上が得られ、また操舵速度の
速い場合のヨーイングの発生を促すことができ、加えて
後輪の転舵角速度すなわち過渡的な転舵角度は走行路面
の摩擦係数が小さい場合に大きくなり、摩擦係数の低い
路面での安定性を高めることができ、後輪の転舵角に走
行路面の摩擦係数に依存した特性を付与でき、走行路面
の摩擦係数の如何にかかわらず良好な旋回特性が得られ
る。(Operation) According to the steering control apparatus for a front-rear-wheel steered vehicle according to the present invention, the temporal change in the turning angle of the rear wheel occurs substantially corresponding to the friction coefficient of the traveling road surface, and the determined target steering of the rear wheel is determined. In order to correct the force so as to be smaller when the temporal change is large according to the temporal change in the steering angle of the front wheels, stability can be improved at a normal steering speed, and when the steering speed is high, It can promote yawing, and in addition, the steering angular velocity of the rear wheels, that is, the transient steering angle, increases when the friction coefficient of the running road surface is small, and the stability on a road surface with a low friction coefficient can be improved. As a result, characteristics that depend on the friction coefficient of the traveling road surface can be given to the turning angle of the rear wheels, and good turning characteristics can be obtained regardless of the friction coefficient of the traveling road surface.

（実施例） 以下、この発明の実施例を図面を参照して説明する。Hereinafter, embodiments of the present invention will be described with reference to the drawings.

第２図から第６図はこの発明の一実施例にかかる前後
輪操舵車両の操舵制御装置を示し、第２図が全体概略
図、第３図がブロック図、第４図がフローチャートであ
る。2 to 6 show a steering control device for a front-rear-wheel steering vehicle according to an embodiment of the present invention. FIG. 2 is an overall schematic diagram, FIG. 3 is a block diagram, and FIG. 4 is a flowchart.

第２図において、11は操向ハンドルであり、操向ハン
ドル11はステアリングシャフト12を介してラックアンド
ピニオン式のステアリングギア機構13に連結されてい
る。ステアリングシャフト12には、ステアリングシャフ
ト12の回転角度を検出する舵角センサ（前輪舵角検知手
段）14およびステアリングシャフト12の回転角速度を検
出する操舵速度センサ（前輪操舵速度検知手段）15が設
けられている。舵角センサ14は、エンコーダ等から構成
され、後述するコントローラ16に結線された該コントロ
ーラ16に操舵角度（前輪舵角）を表す検知信号を出力す
る。また、操舵速度センサ15は、コントローラ16に結線
された発電機等から構成され、コントローラ16に操舵速
度（前輪舵角の時間的変化）を表す検知信号を出力す
る。なお、言うまでも無いが、操舵速度センサ15は舵角
センサ14の検知信号を微分演算する微分回路等で代替で
きる。In FIG. 2, reference numeral 11 denotes a steering handle. The steering handle 11 is connected to a rack and pinion type steering gear mechanism 13 via a steering shaft 12. The steering shaft 12 is provided with a steering angle sensor (front wheel steering angle detection means) 14 for detecting the rotation angle of the steering shaft 12 and a steering speed sensor (front wheel steering speed detection means) 15 for detecting the rotation angular velocity of the steering shaft 12. ing. The steering angle sensor 14 includes an encoder or the like, and outputs a detection signal indicating a steering angle (front wheel steering angle) to the controller 16 connected to the controller 16 described later. Further, the steering speed sensor 15 is constituted by a generator or the like connected to the controller 16, and outputs a detection signal indicating the steering speed (the temporal change of the front wheel steering angle) to the controller 16. Needless to say, the steering speed sensor 15 can be replaced with a differentiating circuit or the like for differentiating the detection signal of the steering angle sensor 14.

ステアリングギア機構13は、周知のように、ステアリ
ングシャフト12と一体的に回転するピニオンギア13aお
よびピニオンギア13aと噛合して車幅方向に延在するラ
ック13bを備え、ラック13bの両端がそれぞれ、左右の前
輪18FL,18FRのナックルアーム19FL,19FRにタイロッド17
FL,17FR等から成るステアリングリンケージを介して連
結されている。これら前輪18FL,18FRにはそれぞれ車速
センサ20FL,20FRが設けられ、これら車速センサ20FL,20
FRがコントローラ16に結線されて車速を表す信号を出力
する。また、後述するように、後輪18RL,18RRにもそれ
ぞれ車速センサ20RL,20RRが設けられ、これら車速セン
サ20RL,20RRもコントローラ16に結線されて車速を表す
信号を出力する。なお、言うまでもないが、前述の舵角
センサ14はステアリングギア機構13のラック13bの移動
距離あるいは前輪18FL,18FRの舵角を検知するセンサで
代替できる。As is well known, the steering gear mechanism 13 includes a pinion gear 13a that rotates integrally with the steering shaft 12, and a rack 13b that meshes with the pinion gear 13a and extends in the vehicle width direction. Tie rod 17 on left and right front wheel 18FL, 18FR knuckle arm 19FL, 19FR
They are connected via a steering linkage composed of FL, 17FR, etc. These front wheels 18FL and 18FR are provided with vehicle speed sensors 20FL and 20FR, respectively.
The FR is connected to the controller 16 and outputs a signal indicating the vehicle speed. Further, as will be described later, vehicle speed sensors 20RL and 20RR are also provided on the rear wheels 18RL and 18RR, respectively, and these vehicle speed sensors 20RL and 20RR are also connected to the controller 16 and output a signal representing the vehicle speed. Needless to say, the aforementioned steering angle sensor 14 can be replaced by a sensor that detects the moving distance of the rack 13b of the steering gear mechanism 13 or the steering angle of the front wheels 18FL and 18FR.

21はコントローラ16に結線されて該コントローラ16か
ら給電される電動機であり、電動機21は出力軸が傘歯車
機構22を介してラックアンドピニオン式のステアリング
ギア機構23に連結されている。傘歯車機構22は、電動機
21の出力軸に固設された傘歯車22bおよびステアリング
ギア機構23のピニオンギヤ23aと一体的に回転する傘歯
車22aを有している。ステアリングギア機構23は、前述
のステアリングギア機構23と同様にピニオンギア23aお
よびラック23bを有し、ピニオンギア23aが電動機21に傘
歯車機構22を介し連結され、ラック23bの両端がそれぞ
れ左右の後輪18RL,18RRのナックルアーム19RL,19RRにタ
イロッド17RL,17RR等から成るステアリングリンケージ
を連結されている。ステアリングギア機構23のラック23
bには、該ラック23bの軸方向の移動距離を検出する後輪
舵角センサが24が設けられている。後輪舵角センサ24
は、差動トランス等から構成されてコントローラ16に結
線され、ラック23bの移動距離で後輪18RL,18RRの舵角を
検出して該舵角を表す信号をコントローラ16に出力す
る。この後輪舵角センサ24は、周知のように、コントロ
ーラ16から交流パルス信号が一次コイルに入力し、ラッ
ク23bとともにコアが変位して二次コイルから差動信号
を出力する。なお、この実施例では電動機21を後輪18R
L,18RRの転舵専用に設けているが、電動機21の出力を前
輪18FL,18FRとともに後輪18RL,18RRへ分配し、後輪18R
L,18RRへの操舵力の伝達系に舵角関数発生機構等を付加
したものでもこの発明が達成されることは言うまでもな
い。Reference numeral 21 denotes a motor connected to the controller 16 and supplied with power from the controller 16. The motor 21 has an output shaft connected to a rack-and-pinion type steering gear mechanism 23 via a bevel gear mechanism 22. The bevel gear mechanism 22 is an electric motor
It has a bevel gear 22b fixed to the output shaft 21 and a bevel gear 22a that rotates integrally with the pinion gear 23a of the steering gear mechanism 23. The steering gear mechanism 23 has a pinion gear 23a and a rack 23b similarly to the steering gear mechanism 23 described above. The pinion gear 23a is connected to the electric motor 21 via the bevel gear mechanism 22, and both ends of the rack 23b A steering linkage including tie rods 17RL and 17RR is connected to knuckle arms 19RL and 19RR of the wheels 18RL and 18RR. Rack 23 of steering gear mechanism 23
b is provided with a rear wheel steering angle sensor 24 for detecting the axial movement distance of the rack 23b. Rear wheel steering angle sensor 24
Is composed of a differential transformer or the like, is connected to the controller 16, detects the steering angle of the rear wheels 18RL, 18RR based on the moving distance of the rack 23b, and outputs a signal representing the steering angle to the controller 16. As is well known, the rear wheel steering angle sensor 24 receives an AC pulse signal from the controller 16 and inputs the primary coil to the primary coil, displaces the core together with the rack 23b, and outputs a differential signal from the secondary coil. In this embodiment, the electric motor 21 is connected to the rear wheel 18R.
L, 18RR is provided exclusively for steering, but the output of the motor 21 is distributed to the rear wheels 18RL, 18RR together with the front wheels 18FL, 18FR, and the rear wheels 18R.
Needless to say, the present invention can be achieved even when a steering angle function generating mechanism or the like is added to the transmission system of the steering force to L, 18RR.

コントローラ16は、第３図に示すように制御回路25お
よび駆動回路26を有し、制御回路25に前述したセンサ1
4,15,20,24とともに後述する駆動回路26の電流センサ28
が接続され、また、駆動回路26に前述の電動機21が接続
されている。The controller 16 has a control circuit 25 and a drive circuit 26 as shown in FIG.
The current sensor 28 of the drive circuit 26 described later together with 4,15,20,24
Are connected, and the electric motor 21 is connected to the drive circuit 26.

制御回路25は、定電圧回路30、マイクロコンピュータ
回路31および入力インターフェース回路32,33,34,35,37
等を備えている。定電圧回路30は、バッテリにフューズ
等を介し接続され、各回路に一定電圧の電力を供給す
る。入力インターフェース回路32,33,34,35,37は、それ
ぞれが対応する前述の各センサ14,15,20,24,28に接続さ
れ、また、データバスを介してマイクロコンピュータ回
路31に接続されている。舵角センサ14に接続された入力
インターフェース回路32は舵角センサ14の出力信号を処
理してマイクロコンピュータ回路31に前輪18FL,18FRの
操舵角度と方向とを表す信号を出力する。操舵速度セン
サ15が接続した入力インターフェース回路33は操舵速度
センサ15の検知信号を処理してマイクロコンピュータ回
路31に操舵速度を表すデジタル信号を出力する。また、
後輪舵角センサ24に接続されたインターフェース回路35
は、発振回路、整流回路およびローパスフィルタ等から
成り、後輪舵角センサ24の一次コイルに交流パルス信号
を出力するとともに二次コイルからの信号を整形してマ
イクロコンピュータ回路31に出力する。車速センサ20に
接続されたインターフェース回路34は、波形整形回路お
よび演算回路等から成り、各車速センサ20の出力信号を
基に車速を表す信号をマイクロコンピュータ回路31へ出
力する。電流センサ28に接続されたインターフェース回
路37は、増幅回路およびA/Dコンバータ等を備え、電流
センサ28の出力信号をデジタル信号に変換してマイクロ
コンピュータ回路31に出力する。The control circuit 25 includes a constant voltage circuit 30, a microcomputer circuit 31, and input interface circuits 32, 33, 34, 35, and 37.
Etc. are provided. The constant voltage circuit 30 is connected to the battery via a fuse or the like, and supplies a constant voltage power to each circuit. The input interface circuits 32, 33, 34, 35, and 37 are connected to the corresponding sensors 14, 15, 20, 24, and 28, respectively, and also connected to the microcomputer circuit 31 via a data bus. I have. The input interface circuit 32 connected to the steering angle sensor 14 processes the output signal of the steering angle sensor 14 and outputs a signal representing the steering angle and direction of the front wheels 18FL, 18FR to the microcomputer circuit 31. The input interface circuit 33 connected to the steering speed sensor 15 processes the detection signal of the steering speed sensor 15 and outputs a digital signal indicating the steering speed to the microcomputer circuit 31. Also,
Interface circuit 35 connected to rear wheel steering angle sensor 24
Is composed of an oscillating circuit, a rectifying circuit, a low-pass filter, etc., and outputs an AC pulse signal to the primary coil of the rear wheel steering angle sensor 24, and also shapes a signal from the secondary coil to output to the microcomputer circuit 31. The interface circuit 34 connected to the vehicle speed sensor 20 includes a waveform shaping circuit, an arithmetic circuit, and the like, and outputs a signal representing the vehicle speed to the microcomputer circuit 31 based on the output signal of each vehicle speed sensor 20. The interface circuit 37 connected to the current sensor 28 includes an amplifier circuit, an A / D converter, and the like, converts an output signal of the current sensor 28 into a digital signal, and outputs the digital signal to the microcomputer circuit 31.

マイクロコンピュータ回路31は、CPU、ROM、RAMおよ
びクロック等を備え、ROMに記憶されたプログラムに従
い各インターフェース回路32,33,34,35,を経て各センサ
から入力する信号を処理して電動機21へ通電する電流の
デューティファクタを決定し、このデューティファクタ
を表すパルス幅変調信号（PWM信号）g,h,i,jを駆動回路
26に出力する。The microcomputer circuit 31 includes a CPU, a ROM, a RAM, a clock, and the like, processes a signal input from each sensor via each interface circuit 32, 33, 34, 35 according to a program stored in the ROM, and sends the processed signal to the electric motor 21. The duty factor of the current to be supplied is determined, and a pulse width modulation signal (PWM signal) g, h, i, j representing the duty factor is supplied to the drive circuit.
Output to 26.

駆動回路26は、昇圧回路38、ゲートドライブ回路39、
電流センサ28、リレー回路41およびスイッチ回路40等を
備え、ゲートドライブ回路39がバッテリに接続され、ま
た、スイッチ回路40がリレー回路41を介しバッテリに接
続されている。スイッチ回路40は、４つの電界効果型ト
ランジスタ（FET）Q1,Q2,Q3,Q4をブリッジ状に結線して
成り、これらFETQ1,Q2,Q3,Q4のゲートがゲートドライブ
回路39に接続されている。FETQ1,Q2は、ドレインがバッ
テリに接線されてソースがFETQ3,Q4のドレインに接続さ
れ、また、FETQ3,Q4はソースが電流センサ28を介し接地
（バッテリの一端子）され、FETQ1,Q3のソース・ドレイ
ン接続部とFETQ2,Q4のソース・ドレイン接続部との間に
電動機21が接続されている。昇圧回路38はバッテリの電
圧を昇圧してゲートドライブ回路39に出力し、ゲートド
ライブ回路39はマイクロコンピュータ回路31から入力す
るPWM信号g,h,i,jに基づいてスイッチ回路40の各FETQ1,
Q2,Q3,Q4のゲートに駆動信号を出力する。電流センサ28
は電動機21に通電された電流を検出してこの電流の検知
信号を前述のインターフェース回路37に出力する。な
お、スイッチ回路40は、FETQ1のゲートにPWM信号ｇに対
応したデューティファクタの駆動信号が入力し、同様
に、FETQ2のゲートにPWM信号ｈ、FETQ3のゲートにPWM信
号ｉ、FETQ4のゲートにPWM信号ｊのデューティファクタ
の駆動信号がそれぞれ入力する。The drive circuit 26 includes a booster circuit 38, a gate drive circuit 39,
It includes a current sensor 28, a relay circuit 41, a switch circuit 40, and the like. The gate drive circuit 39 is connected to the battery, and the switch circuit 40 is connected to the battery via the relay circuit 41. The switch circuit 40 is formed by connecting four field effect transistors (FETs) Q1, Q2, Q3, and Q4 in a bridge shape, and the gates of these FETs Q1, Q2, Q3, and Q4 are connected to a gate drive circuit 39. . The drains of the FETs Q1 and Q2 are connected to the battery and the sources are connected to the drains of the FETs Q3 and Q4. The sources of the FETs Q3 and Q4 are grounded (one terminal of the battery) via the current sensor 28, and the sources of the FETs Q1 and Q3 are connected. The electric motor 21 is connected between the drain connection and the source / drain connection of the FETs Q2 and Q4. The booster circuit 38 boosts the voltage of the battery and outputs the boosted voltage to the gate drive circuit 39.The gate drive circuit 39 uses the PWM signals g, h, i, j input from the microcomputer circuit 31 to output the FETs Q1,
A drive signal is output to the gates of Q2, Q3, and Q4. Current sensor 28
Detects the current supplied to the motor 21 and outputs a detection signal of the current to the interface circuit 37 described above. The switch circuit 40 receives a drive signal having a duty factor corresponding to the PWM signal g at the gate of the FET Q1, similarly outputs a PWM signal h to the gate of the FET Q2, a PWM signal i to the gate of the FET Q3, and a PWM signal to the gate of the FET Q4. A drive signal having a duty factor of the signal j is input.

次に、この実施例の作用を第４図を参照して説明す
る。Next, the operation of this embodiment will be described with reference to FIG.

この前後輪操舵装置の操舵制御装置は、マイクロコン
ピュータ回路31において第４図のフローチャートに示す
一連の処理を実行して電動機21を制御する。The steering control device of the front and rear wheel steering device controls the electric motor 21 by executing a series of processes shown in the flowchart of FIG.

まず、イグニッションキーが操作されてキースイッチ
がON位置に投入されると、マイクロコンピュータ回路31
等に電力が供給され、マイクロコンピュータ回路31が作
動する。そして、ステップP1では、マイクロコンピュー
タ回路31の初期化（イニシャライズ）が行なわれ、内部
のレジスタ等の記憶データの消去およびアドレス指定等
行う。続いて、ステップP2においては、他に定義されて
いるサブルーチンに従い初期故障診断が行なわれ、全て
が正常に機能している場合にのみ以下の処理を行う。First, when the ignition key is operated and the key switch is turned on, the microcomputer circuit 31 is turned on.
And the like, and the microcomputer circuit 31 operates. Then, in step P1, the microcomputer circuit 31 is initialized (initialized), and erases stored data such as internal registers and specifies addresses. Subsequently, in step P2, an initial failure diagnosis is performed in accordance with another defined subroutine, and the following processing is performed only when all are functioning normally.

ステップP3においては、各車速センサ20の出力信号か
ら車速Ｖを読み込み、続くステップP4において、車速Ｖ
をアドレスとして、第５図に示すデータテーブル１から
舵角比ｋをマップ検索する。この舵角比ｋは、第５図か
ら明らかなように、所定車速V1より小さな低車速域にお
いて急値（逆位相を表す）、所定車速V1より大きな高車
速域において正値（同位相を表す）を有する。In step P3, the vehicle speed V is read from the output signal of each vehicle speed sensor 20, and in subsequent step P4, the vehicle speed V
Is used as an address, a map search is performed for the steering angle ratio k from the data table 1 shown in FIG. As is clear from FIG. 5, the steering angle ratio k is a sharp value (representing an opposite phase) in a low vehicle speed range lower than the predetermined vehicle speed V1, and a positive value (representing the same phase) in a high vehicle speed range higher than the predetermined vehicle speed V1. ).

次に、ステップP5においては、舵角センサ14の出力信
号θ′Ｆを読み込み、ステップP6において舵角センサ14
の中立補正係数θＭにより中立位置からの舵角θＦ（θ
Ｆ＝θ′Ｆ−θＭ）を算出する。この舵角θＦはステア
リングシャフト12の回転角が前輪18FL,18FRの舵角と対
応するため前輪18FL,18FRの舵角を表す（以下、前輪舵
角と記す）。続いて、ステップP7では、前輪舵角θＦの
正負すなわち方向を判別し、前輪舵角θＦが正であれば
ステップP8でフラグF1を０に設定し、また、前輪舵角θ
Ｆが負であればステップP9で前輪舵角θＦを正値化（絶
対値化）した後にステップP10でフラグF1を１に設定す
る。そして、次のステップP11において、前輪舵角θＦ
に舵角比ｋを乗じて後輪18RL,18RRの目標舵角（後輪目
標舵角）θRTを算出する。Next, in step P5, the output signal θ′F of the steering angle sensor 14 is read, and in step P6, the steering angle sensor 14
The steering angle θF from the neutral position (θ
F = θ′F−θM). The steering angle θF represents the steering angle of the front wheels 18FL, 18FR because the rotation angle of the steering shaft 12 corresponds to the steering angle of the front wheels 18FL, 18FR (hereinafter referred to as the front wheel steering angle). Subsequently, in step P7, the sign of the front wheel steering angle θF, that is, the direction is determined. If the front wheel steering angle θF is positive, the flag F1 is set to 0 in step P8, and the front wheel steering angle θ
If F is negative, the front wheel steering angle θF is set to a positive value (absolute value) in step P9, and then the flag F1 is set to 1 in step P10. Then, in the next step P11, the front wheel steering angle θF
Is multiplied by a steering angle ratio k to calculate a target steering angle (rear wheel target steering angle) θRT of the rear wheels 18RL and 18RR.

次に、ステップP12においては、車速Ｖが所定車速V0
を超えているか否かを判断し、車速Ｖが所定車速V0を超
えていればステップP13,P14,P15の処理を行い、また、
車速Ｖが所定車速V0以下であればステップP16,P17,P18
の処理を行う。ステップP13では、フラグF1の値を判別
し、フラグF1が１であればステップP14でフラグF3を１
に設定し、また、フラグF1が０であればステップP15で
フラグF3を０に設定する。同様に、ステップP16では、
フラグF1の値を判別し、フラグF1が１であればステップ
P17でフラグF3に０を設定し、またフラグF1が０であれ
ばステップP18でフラグF3を１に設定する。Next, in step P12, the vehicle speed V becomes the predetermined vehicle speed V 0.
It is determined whether it exceeds the vehicle speed V is performs steps P13, P14, P15 if beyond a predetermined vehicle speed V 0, also,
If the vehicle speed V is equal to or less than the predetermined vehicle speed V 0 Step P16, P17, P18
Is performed. In Step P13, the value of the flag F1 is determined. If the flag F1 is 1, the flag F3 is set to 1 in Step P14.
If the flag F1 is 0, the flag F3 is set to 0 in step P15. Similarly, in step P16,
Determine the value of the flag F1, and if the flag F1 is 1, step
In P17, the flag F3 is set to 0, and if the flag F1 is 0, the flag F3 is set to 1 in Step P18.

続くステップP19においては、後輪舵角センサ24の出
力信号θR1,θR2を読み込み、ステップP20で他に定義さ
れているサブルーチンに従い後輪舵角センサ24の故障診
断を行う。このステップP20では、後輪舵角センサ24が
正常に機能していると診断された場合にのみ以下の処理
を実行する。そして、ステップP21において、後輪舵角
センサ24の出力信号θR1,θR2を減算処理して後輪舵角
θＲを算出する。続いて、ステップ22において、後輪舵
角θＲの正負を判別し、後輪舵角θＲが正であればステ
ップP23でフラグF2を０に設定し、また、後輪舵角θＲ
が負であればステップP24で後輪舵角θＲを正値化（絶
対値化）した後ステップP25でフラグF2を１に設定す
る。次のステップP26においては、フラグF2とフラグF3
との値を判別し、フラグF2,F3の値が異なればステップP
27の処理を行い、また、フラグF2,F3が同値であればス
テップP28からステップP33までの処理を行う。ステップ
P27では、後輪目標舵角θRTと後輪舵角θＲとを加算し
て偏差ΔθＲを算出する。また、ステップP28では後輪
目標舵角θRTから後輪舵角θＲを減じて偏差ΔθＲを算
出し、この後、ステップP29で偏差ΔθＲの正負を判別
する。このステップP29では、偏差ΔθＲが質であると
判別されると、ステップP30で偏差ΔθＲを正値化した
後にステップP31,P32,P33でフラグF3の値を置換する。
すなわち、ステップP31でフラグF3の値を判別し、フラ
グF3が０であればステップP32でフラグF3を１に置換
し、また、フラグF3が１であればステップP33でフラグF
3を０に置換する。In the following step P19, the output signals θR1 and θR2 of the rear wheel steering angle sensor 24 are read, and failure diagnosis of the rear wheel steering angle sensor 24 is performed in accordance with a subroutine defined elsewhere in step P20. In this step P20, the following processing is executed only when it is determined that the rear wheel steering angle sensor 24 is functioning normally. Then, in step P21, the rear wheel steering angle θR is calculated by subtracting the output signals θR1 and θR2 of the rear wheel steering angle sensor 24. Subsequently, in step 22, it is determined whether the rear wheel steering angle θR is positive or negative. If the rear wheel steering angle θR is positive, the flag F2 is set to 0 in step P23, and the rear wheel steering angle θR
Is negative, the rear wheel steering angle θR is converted to a positive value (absolute value) in step P24, and the flag F2 is set to 1 in step P25. In the next step P26, the flag F2 and the flag F3
Is determined, and if the values of the flags F2 and F3 are different, step P
27. If the flags F2 and F3 have the same value, the process from step P28 to step P33 is performed. Steps
In P27, the deviation ΔθR is calculated by adding the rear wheel target steering angle θRT and the rear wheel steering angle θR. In step P28, the deviation ΔθR is calculated by subtracting the rear wheel steering angle θR from the rear wheel target steering angle θRT, and thereafter, in step P29, the sign of the deviation ΔθR is determined. In this step P29, if the deviation ΔθR is determined to be quality, the value of the flag F3 is replaced in steps P31, P32, and P33 after the deviation ΔθR is made positive in step P30.
That is, the value of the flag F3 is determined in step P31. If the flag F3 is 0, the flag F3 is replaced with 1 in step P32. If the flag F3 is 1, the flag F3 is changed in step P33.
Replace 3 with 0.

続くステップP34においては操舵速度センサ15の検知
信号から操舵速度Ｆを読み込み、ステップP35におい
て、第６図に示すデータテーブル２から操舵速度θＦを
アドレスとして補正係数αをマップ検索する。そして、
ステップP36において、上述の偏差ΔθＲに補正係数α
を乗じて偏差ΔθＲを補正する。上記第６図から明らか
なように、補正係数αは操舵速度Ｆが低い領域で概略
１、操舵速度Ｆが高い領域において漸減して零になる
ため、この補正係数αで補正された偏差ΔθＲは操舵速
度Ｆが高い領域で小さくなる。In a succeeding step P34, the steering speed F is read from the detection signal of the steering speed sensor 15, and in a step P35, a map search for the correction coefficient α is performed using the steering speed θF as an address from the data table 2 shown in FIG. And
In step P36, the correction coefficient α
To correct the deviation ΔθR. As is apparent from FIG. 6, the correction coefficient α is approximately 1 in a low steering speed F region, and gradually decreases to zero in a high steering speed F region, so that the deviation ΔθR corrected by the correction coefficient α is It becomes smaller in a region where the steering speed F is high.

次に、ステップP37において、第７図に示すデータテ
ーブル３から偏差ΔθＲをアドレスとして後輪操舵力Ｄ
をマップ検索する。この後輪操舵力Ｄは、電動機21に通
電する電流のデューティファクタすなわち電流値を表
し、０に近い低偏差域では０の不感帯を有し、偏差の増
加に従い増加して高偏差域で一定値をとる。Next, in step P37, the rear wheel steering force D is determined from the data table 3 shown in FIG.
Search by map. The rear wheel steering force D represents a duty factor of a current supplied to the electric motor 21, that is, a current value. The rear wheel steering force D has a dead zone of 0 in a low deviation region close to 0, and increases as the deviation increases and becomes a constant value in a high deviation region. Take.

このステップP37では、上述のように偏差ΔθＲは操
舵速度Ｆに基づき補正されて操舵速度θＦが大きい領
域で前述のステップP27,P28で算出された偏差よりも小
さくなるため、操舵力Ｄも操舵速度Ｆが小さい領域よ
りも大きい領域で小さくなる。In this step P37, the deviation ΔθR is corrected based on the steering speed F as described above, and becomes smaller than the deviation calculated in steps P27 and P28 in the region where the steering speed θF is large. It becomes smaller in a region where F is larger than a region where F is small.

続く、ステップP38においては、後輪操舵力Ｄが０か
否かを判別し、後輪操舵力Ｄが０であればステップP39
でPWM信号g,h,i,jにそれぞれ0,0,1,1を設定し、また、
後輪駆動力Ｄが０でなければステップP40でフラグF3の
値を判別する。このステップP40では、フラグF3が０で
あると判断されるとステップP41でPWM信号g,h,i,jにそ
れぞれ1,0,0,Dを設定し、また、フラグF3が１と判断さ
れるとステップP42でPWM信号g,h,i,jにそれぞれ0,1,D,0
を設定する。そして、ステップP43でPWM信号g,h,i,jを
出力する。したがって、電動機21は、後輪18RL,18RRの
転舵方向に応じデューティファクタＤの電流が通電され
て該電流に応じた操舵力で後輪18RL,18RRを目標舵角ま
で転舵し、また、非通電時には巻線が短絡されて電気制
動を行い後輪舵角を目標舵角に保持する。この後、ステ
ップP44で他に定義されたサブルーチンに従い電動機21
およびスイッチ回路40等の駆動系の故障診断を行い、再
度、ステップP2からの一連の処理を繰り返す。In a succeeding step P38, it is determined whether or not the rear wheel steering force D is 0. If the rear wheel steering force D is 0, a step P39 is executed.
Set 0,0,1,1 to the PWM signals g, h, i, j respectively,
If the rear wheel driving force D is not 0, the value of the flag F3 is determined in step P40. In this step P40, when it is determined that the flag F3 is 0, in step P41, the PWM signals g, h, i, j are set to 1, 0, 0, D, respectively, and the flag F3 is determined to be 1. Then, in step P42, the PWM signals g, h, i, j are 0, 1, D, 0, respectively.
Set. Then, in step P43, the PWM signals g, h, i, j are output. Accordingly, the electric motor 21 is supplied with a current having a duty factor D according to the steering direction of the rear wheels 18RL, 18RR, and steers the rear wheels 18RL, 18RR to a target steering angle with a steering force corresponding to the current. When the power is not supplied, the winding is short-circuited to perform electric braking, and the rear wheel steering angle is maintained at the target steering angle. Thereafter, in step P44, the motor 21
Then, a failure diagnosis of the drive system such as the switch circuit 40 is performed, and a series of processes from Step P2 is repeated again.

上述のように、この実施例の操舵制御装置にあって
は、後輪18RL,18RRの実舵角θＲと車速等に応じ決定さ
れる目標舵角θRTとの偏差ΔθＲに応じた電流を電動機
21に通電し、後輪18RL,18RRを電動機21によって偏差を
減少すべく転舵する。そして、検出された後輪舵角θＲ
と目標舵角θRTとの偏差ΔθＲは操舵速度Ｆが大きい
場合すなわち走行路面の摩擦係数が小さい場合に減少補
正されて後輪の操舵力Ｄが小さくなるため、後輪の転舵
角速度すなわち過渡的な転舵角に走行路面の摩擦係数に
依存した特性を付与でき、走行路面の摩擦係数の如何に
かかわらず良好な旋回性能が得られる。As described above, in the steering control device of the present embodiment, the electric motor according to the deviation ΔθR between the actual steering angle θR of the rear wheels 18RL, 18RR and the target steering angle θRT determined according to the vehicle speed, etc.
The power is supplied to the motor 21 and the rear wheels 18RL and 18RR are steered by the electric motor 21 to reduce the deviation. Then, the detected rear wheel steering angle θR
The deviation ΔθR between the target steering angle θRT and the target steering angle θRT is corrected to be reduced when the steering speed F is high, that is, when the friction coefficient of the traveling road surface is small, and the steering force D of the rear wheel is reduced. A characteristic that depends on the friction coefficient of the traveling road surface can be given to a large turning angle, and good turning performance can be obtained regardless of the friction coefficient of the traveling road surface.

第８図には、この発明の他の実施例にかかる前後輪操
舵車両の操舵制御装置を示す。なお、同図中、ステップ
P1からステップP33、ステップP34、ステップP35、ステ
ップP38からステップP44は、それぞれ前述の第４図中の
ステップP1からステップP33、ステップP37、ステップP3
4、ステップP38からステップP44と同一であり説明を省
略する。FIG. 8 shows a steering control device for a front and rear wheel steering vehicle according to another embodiment of the present invention. Note that in FIG.
P1 to step P33, step P34, step P35, and step P38 to step P44 correspond to step P1 to step P33, step P37, and step P3 in FIG.
4. Steps P38 to P44 are the same as those described above and will not be described.

この実施例では、ステップP36において、第９図に示
すデータテーブル４から操舵速度Ｆをアドレスとして
補正操舵力Dsをマップ検索し、続くステップP37で操舵
力Ｄから補正操舵力Dsを減算して操舵力Dsを補正する。
補正操舵力Dsは、第９図に明らかなように、操舵速度
Ｆが高い領域で０から漸増して所定値になる特性を有す
るため、この補正操舵力Dsを減算された操舵力Ｄは操舵
速度Ｆが高い領域で小さくなる。したがって、この実
施例においても、後輪の操舵速度に走行路面の摩擦係数
に依存した特性を付与でき、走行路面の摩擦係数の如何
にかかわらず良好な旋回特性を得られる。In this embodiment, in step P36, the map is searched for the corrected steering force Ds using the steering speed F as an address from the data table 4 shown in FIG. 9, and in the subsequent step P37, the corrected steering force Ds is subtracted from the steering force D to perform steering. Correct the force Ds.
As apparent from FIG. 9, the corrected steering force Ds has a characteristic that gradually increases from 0 to a predetermined value in a region where the steering speed F is high, so that the steering force D obtained by subtracting the corrected steering force Ds is the steering force. It becomes smaller in a region where the speed F is high. Therefore, also in this embodiment, a characteristic that depends on the friction coefficient of the traveling road surface can be given to the steering speed of the rear wheel, and good turning characteristics can be obtained regardless of the friction coefficient of the traveling road surface.

なお、上述した各実施例では、電動機21により後輪18
RL,18RRを転舵するが、油圧アクチュエータ等によって
も本発明が達成されることは言うまでもない。In each of the above-described embodiments, the electric motor 21 controls the rear wheel 18.
Although the RL and 18RR are steered, it is needless to say that the present invention can be achieved by a hydraulic actuator or the like.

（発明の効果） 以上説明したように、この発明にかかる前後輪操舵車
両の操舵制御装置によれば、後輪の操舵力を前輪の転舵
角の時間的変化に応じ調整するため、後輪の転舵角に走
行路面の摩擦係数に依存した特性を付与でき、後輪の転
舵角が走行路面の摩擦係数によって受ける影響を排除し
て走行路面の摩擦係数の如何にかかわらず良好な旋回性
能が得られる。(Effects of the Invention) As described above, according to the steering control device for a front-rear-wheel steered vehicle according to the present invention, the rear-wheel steering force is adjusted according to the temporal change of the front-wheel turning angle. A characteristic that depends on the friction coefficient of the running road surface can be given to the turning angle of the vehicle, and the turning angle of the rear wheels can be removed regardless of the friction coefficient of the running road surface by eliminating the influence of the friction coefficient of the running road surface. Performance is obtained.

【図面の簡単な説明】[Brief description of the drawings]

第１図はこの発明の操舵制御装置の概念図である。第２
図から第７図はこの発明の一実施例にかかる操舵制御装
置を示し、第２図が全体概略図、第３図がブロック図、
第４図がフローチャート、第５図、第６図および第７図
が制御処理に用いるデータテーブルである。第８図およ
び第９図はこの発明の他の実施例にかかる操舵制御装置
を示し、第８図がフローチャート、第９図が制御処理の
データテーブルである。 11……操向ハンドル 14……舵角センサ（前輪舵角検知手段） 15……操舵速度センサ（前輪操舵速度検知手段） 16……コントローラ 18FL,18FR……前輪 18RL,18RR……後輪 20……車速センサ（車速検知手段） 21……電動機（駆動手段） 24……後輪舵角センサ 25……制御回路 26……駆動回路 31……マイクロコンピュータ回路 （後輪目標舵角決定手段、後輪操舵力決定手段、操舵力
補正手段）FIG. 1 is a conceptual diagram of a steering control device according to the present invention. Second
FIG. 7 to FIG. 7 show a steering control device according to an embodiment of the present invention, FIG. 2 is an overall schematic diagram, FIG.
FIG. 4 is a flowchart, and FIGS. 5, 6, and 7 are data tables used for control processing. 8 and 9 show a steering control device according to another embodiment of the present invention. FIG. 8 is a flowchart, and FIG. 9 is a data table of control processing. 11 Steering handle 14 Steering angle sensor (front wheel steering angle detecting means) 15 Steering speed sensor (front wheel steering speed detecting means) 16 Controller 18FL, 18FR Front wheel 18RL, 18RR Rear wheel 20 …… Vehicle speed sensor (vehicle speed detection means) 21 …… Electric motor (drive means) 24 …… Rear wheel steering angle sensor 25 …… Control circuit 26 …… Drive circuit 31 …… Microcomputer circuit (rear wheel target steering angle determination means, Rear wheel steering force determination means, steering force correction means)

フロントページの続き (56)参考文献 特開 昭62−149561（ＪＰ，Ａ) 特開 昭61−247576（ＪＰ，Ａ) 特開 昭62−18367（ＪＰ，Ａ) 特開 昭62−39369（ＪＰ，Ａ)Continuation of the front page (56) References JP-A-62-149561 (JP, A) JP-A-61-247576 (JP, A) JP-A-62-18367 (JP, A) JP-A-62-39369 (JP) , A)

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】操向ハンドルの操舵に応じ前輪とともに後
輪を転舵する前後輪操舵車両において、 前輪の転舵角度を検出する前輪舵角検知手段と、 後輪の転舵角度を検出する後輪舵角検知手段と、 車速を検出する車速検知手段と、 該車速検知手段により検出された車速および前記前輪舵
角検知手段により検出された前輪の転舵角度に応じて後
輪の目標転舵角度を決定する後輪目標舵角決定手段と、 該後輪目標舵角決定手段により決定された後輪の目標転
舵角度と前記後輪舵角検知手段により検出された後輪の
転舵角度との偏差に応じて後輪の目標操舵力を決定する
後輪操舵力決定手段と、 前輪の転舵角度の時間的変化を検出する前輪操舵速度検
知手段と、 該操舵速度検知手段により検出された時間的変化に応じ
て前記後輪操舵力決定手段により決定された目標操舵力
を前記時間的変化が大きい場合に小さくなるように補正
する操舵力補正手段と、 該操舵力補正手段により補正された目標操舵力で後輪を
目標転舵角度に転舵する駆動手段と、 を備えることを特徴とする前後輪操舵車両の操舵制御装
置。1. A front-wheel steering vehicle that steers a rear wheel together with a front wheel in response to steering of a steering wheel, a front-wheel steering angle detecting means for detecting a steering angle of a front wheel, and detecting a steering angle of a rear wheel. Rear wheel steering angle detecting means; vehicle speed detecting means for detecting vehicle speed; target turning of rear wheels according to the vehicle speed detected by the vehicle speed detecting means and the turning angle of the front wheels detected by the front wheel steering angle detecting means. Rear wheel target steering angle determining means for determining a steering angle; a rear wheel target steering angle determined by the rear wheel target steering angle determining means; and a rear wheel steering detected by the rear wheel steering angle detecting means. Rear wheel steering force determining means for determining a target steering force of the rear wheel in accordance with a deviation from the angle; front wheel steering speed detecting means for detecting a temporal change in the steering angle of the front wheel; and detecting by the steering speed detecting means. The rear wheel steering force determining means in accordance with the temporal change Steering force correction means for correcting the determined target steering force so as to become smaller when the temporal change is large; and turning the rear wheels to the target steering angle with the target steering force corrected by the steering force correction means. A steering control device for a front-rear-wheel steering vehicle, comprising: a driving means for steering.
JP14536288A 1987-07-29 1988-06-13 Steering control device for front and rear wheel steering vehicles Expired - Fee Related JP2577436B2 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP14536288A JP2577436B2 (en) 1988-06-13 1988-06-13 Steering control device for front and rear wheel steering vehicles
US07/226,070 US4939653A (en) 1987-07-29 1988-07-29 Method of and apparatus for controlling steering operation of a motor vehicle with steerable front and rear wheels
FR8810305A FR2620674B1 (en) 1987-07-29 1988-07-29 METHOD AND APPARATUS FOR CONTROLLING THE STEERING OPERATION OF A MOTOR VEHICLE WITH STEERING FRONT AND REAR WHEELS
GB8818071A GB2208375B (en) 1987-07-29 1988-07-29 Method of and apparatus for controlling steering operation of a motor vehicle with steerable front and rear wheels
DE3825885A DE3825885A1 (en) 1987-07-29 1988-07-29 METHOD AND DEVICE FOR CONTROLLING THE STEERING PROCESS OF A MOTOR VEHICLE WITH STEERING FRONT AND REAR WHEELS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14536288A JP2577436B2 (en) 1988-06-13 1988-06-13 Steering control device for front and rear wheel steering vehicles

Publications (2)

Publication Number Publication Date
JPH01314670A JPH01314670A (en) 1989-12-19
JP2577436B2 true JP2577436B2 (en) 1997-01-29

Family

ID=15383451

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14536288A Expired - Fee Related JP2577436B2 (en) 1987-07-29 1988-06-13 Steering control device for front and rear wheel steering vehicles

Country Status (1)

Country Link
JP (1) JP2577436B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2537303B2 (en) * 1990-11-30 1996-09-25 本田技研工業株式会社 Front and rear wheel steering system

Also Published As

Publication number Publication date
JPH01314670A (en) 1989-12-19

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