WO2013119147A1 - Système de direction assistée - Google Patents

Système de direction assistée Download PDF

Info

Publication number
WO2013119147A1
WO2013119147A1 PCT/SE2012/000014 SE2012000014W WO2013119147A1 WO 2013119147 A1 WO2013119147 A1 WO 2013119147A1 SE 2012000014 W SE2012000014 W SE 2012000014W WO 2013119147 A1 WO2013119147 A1 WO 2013119147A1
Authority
WO
WIPO (PCT)
Prior art keywords
steering
torque
turning
steering column
column
Prior art date
Application number
PCT/SE2012/000014
Other languages
English (en)
Inventor
Sten Ragnhult
Henrik LINDBĂCK
Gustav NEANDER
Original Assignee
Volvo Lastvagnar Ab
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 Volvo Lastvagnar Ab filed Critical Volvo Lastvagnar Ab
Priority to PCT/SE2012/000014 priority Critical patent/WO2013119147A1/fr
Publication of WO2013119147A1 publication Critical patent/WO2013119147A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
    • B62D5/046—Controlling the motor
    • B62D5/0472—Controlling the motor for damping vibrations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle

Definitions

  • the invention relates to a power steering system for a vehicle and the control of such a system.
  • the invention is in particular directed to a power steering system comprising a hydraulic steering gear for providing an additional steering torque to the steerable wheels in dependence on the steering torque applied to the steering column and an electrical assistance unit for providing an additional torque to the steering column in dependence of the signals from a control unit.
  • Power steering systems are today present in a lot of vehicles in order to provide an additional torque to the steering system.
  • the systems are mainly present in order to allow the driver to steer a vehicle with less torque applied to the steering wheel than if no steering aid system were present.
  • some kind of proportional aid which add a torque to the steering system proportional to the steering torque from the steering wheel.
  • the steering aid may be dependent on further parameters, e.g. the speed of the vehicle and / or the steering angle.
  • Steering aid system may also be used to control the steering feeling for the driver and thus apply a certain torque depending on specific driving conditions.
  • the invention is related to a power steering system which is used in an ordinary steering arrangement for a vehicle comprising a steering wheel which is mechanically connected to steerable wheels via a steering column.
  • the power steering system comprises a hydraulic steering gear mechanically connected to the steerable wheels.
  • This hydraulic steering gear is usually designed to influence the steered wheels or steering axle directly.
  • the hydraulic steering gear may provide a steering torque at essentially any part of the steering system and could for example influence the steering column.
  • the additional steering torque to the steerable wheels from the hydraulic steering gear is usually applied in dependence of the mechanically applied steering torque to an input shaft of the hydraulic steering gear.
  • the steering torque provided by the hydraulic steering gear is usually proportional to the torque applied to the steering column.
  • the steering system further includes an electrical assistance unit comprising an electric motor.
  • the electric motor is mechanically connected to the steering column in order to provide a turning torque to the steering column.
  • the steering system further comprises a torque sensor for sensing the applied torque to the steering column and an angle sensor for sensing the steering angle of the steering column.
  • the torque and angle sensors are connected to a control unit which receives input signals from the torque sensor and angle sensor.
  • the control unit is further connected to the electric motor used for controlling the torque applied to the steering column by the electric motor.
  • the electrical assistance unit comprising the electric motor, located such that it provides a torque on the steering column in between said hydraulic steering gear and said steering wheel, i.e. the steering column is connected to the input shaft of the steering gear at a location which is more remote from the steering wheel than where the electric motor of the assistance unit is engaged with the steering column.
  • the electric motor be arranged around said steering column such that the steering column forms part of the rotor of the electric motor.
  • the electric motor is preferably arranged such that the steering column is concentrically located around the steering column.
  • the motor may thus be influencing the steering column without the need of any gear or power transmitting connection which may cause additional delay in the providing of a torque from the electric motor to the steering column.
  • the steering system may be designed such that the hydraulic steering gear is mechanically influenced by both the turning torque applied to the steering column by the manually applied turning force to the steering wheel and the automatically applied turning force by the electrical assistance unit such that a change of torque in the steering column mechanically causes a change in the hydraulic flow.
  • the resulting steering aid from the hydraulic steering gear is the resulting force from both the manually applied steering torque from the steering wheel and the automatically applied torque from the electric motor.
  • the hydraulic steering gear may be constructed to include a torsion bar, which is influenced by the resulting turning torque of the steering column, such that a turning torque on the steering column in a first rotational direction results in an increased pressure of a hydraulic fluid in a first chamber relative a pressure of the hydraulic fluid in a second chamber such that a steering torque aid is provided in said first direction.
  • a turning torque on the steering column in a second rotational direction opposite said first rotational direction, results in an increased pressure of a hydraulic fluid in the second chamber relative a pressure of the hydraulic fluid in the first chamber such that a steering torque aid is provided in said second rotational direction.
  • the hydraulic steering gear is designed to provide an additional steering force in the direction on which there is a turning torque on the steering column.
  • the hydraulic steering gear with electromechanical valves which are influenced by the turning torque applied to the steering column.
  • the steering wheel column could be provided with some kind of torque sensors, e.g. piezoelctric elements, which may indicate the steering torque.
  • the sensed torque may be used to send signals proportional to the resulting force from the manually applied turning force from the steering wheel and the automatically applied turning force by the electrical assistance unit such that a change of torque in the steering column causes the valves to change its positions such that there will be a change of steering torque aid from the hydraulic steering gear.
  • the hydraulic steering aid In such an arrangement it will be possible to adjust the hydraulic steering aid to be different for different driving situations for the same torque, e.g. in dependence of the speed, ground surface or steering angle.
  • the electrical assistance unit since there is an electrical assistance unit present in the power steering system, such adjustments may be made by the electrical assistance unit as well.
  • the torque provided by the electric motor in the electrical assistance unit may be adapted to provide a torque in dependence of the applied steering torque and steering angle.
  • the steering torque aid from the electrical assistance unit may depend on further parameters such as vehicle speed, the direction of travel, the load of the vehicle, ground surface properties, inclination, yaw rate and/or lateral acceleration for example.
  • the torque sensor for sensing the applied steering torque may be a turning torque indicating torsion bar. This sensor will thus sense the applied turning from the turning of the steering wheel.
  • This torsion bar may be a part of the steering column, i.e. the torsion bar will allow a certain play when performing a turning action such that there will be a lag in the turning action of the steerable wheels.
  • the maximum allowable play may be in the interval of 5 to 10 degrees. If there is a turning motion which should cause a torque which twists the torsion bar to the limit, there will be a fixed stop and the remaining torque will be absorbed by a stiff connection in the steering column when the steering torque is above the maximum torque limit value.
  • the turning torque indicating torsion bar may be connected to the steering column at a portion forming part of the electric assistance unit and/or at a location in between the electric assistance unit and the steering wheel.
  • the torque indicating torsion bar is in this case located at a portion of the steering column which is between the engagement of the electric motor on the steering column and the steering wheel connection to the steering column.
  • the turning torque indicating torsion bar may be designed to include and comprises an integrated angle sensor so as to form a torque angle sensing torsion bar in order to provide a compact sensor system for deciding the torque and steering angle.
  • the power steering system described herein may be used for filtering undesired steering torques, originating from deflections or vibrations of the steered wheels, from being transported to the steering wheel and cause an unpleasant feeling for the driver.
  • This may be achieved by using the electrical assistance unit to provide a counterforce which counteracts an undesired turning of the steering wheel and thus the steering column.
  • This feature will also help in keeping the vehicle right on the desired track and counteract deviations of the vehicle from the desired traveling direction.
  • the control unit In order to be able to control the electric assistance unit to counteract undesired influences from the road on the steering system is it necessary for the control unit to be able to detect if the torque on the steering system is induced by the a driver, e.g.
  • the torque sensor may be configured to sense a difference between a torque on the steering column induced by turning of the steering wheel and a torque induced by dislocation of the wheels so as to cause a turning torque on the steering column.
  • the origin of the turning force is there after decided to be the steering wheel if the upper angle sensor is turned first or most and the turning force is decided to originate from dislocation of the wheels if the lower angle sensor is turned first or most.
  • the origin of the turning torque could also be decided based on the turning frequency, e.g. very quick and oscillating turns is most likely originating from the wheels (e.g. driving on a cobble stone road) or a very quick, strong steering impulse turning could be the result of a turning force from hitting a stone by the wheels.
  • control unit may be connected to said torque sensor and angle sensor in order to receive input signals which may be used for indicating the magnitude and origin of the turning force.
  • This input could be used by the control unit if it is programmed to interpret the signals to send a control signal to said electrical assistance unit to provide a counter force which counteracts the initial turning force by providing a turning force in the opposite direction of the same magnitude as the initial force if it is decided the initial force is originating from a dislocation of the turning wheels.
  • a reliable recognition of the origin of the steering force could be established by frequency analysis or turning torque patterns could it be possible to use only the torsion bar for deciding the origin of the turning torque.
  • the electric motor comprised in the electrical assistance unit need not to be very powerful. If the motor is used for efficiently counteract small and quick oscillating turning torques from the wheels, these forces are rather small and the need for a strong assistance from the electric motor is not needed. In the cases there is a desire for a stronger force to be active, the turning torque from the electric motor will get assisted by the steering gear such that there will be an amplification of the turning torque in order to achieve the desired total counteracting torque. Since a smaller motor is easier to fit in the steering system and a rather low steering force is needed in general in order to provide enough torque, the maximum power of the electric motor may be lower than 50 Nm, e.g. within the range 15 - 50 Nm.
  • FIG. 1 Discloses a schematic view of a power steering system
  • FIG. 2 Discloses a schematic view of an electrical assistance unit
  • FIG 1 is schematically described a power steering system 1 according to the invention.
  • the power steering system 1 comprises a steering wheel 2 mechanically connected to a steering column 3.
  • an electrical assistance unit 4 which is mechanically connected to the steering column 3.
  • the electrical assistance unit 4 is connected to a control unit 5 in order to recive control input through an output wire 6 from the control unit 5 and to send input signals from various sensors (not shown in this figure) through an input wire 7 to the control unit to be used for deciding the control output to the electrical assistance unit.
  • the inputs to the control unit 5 is shown to be only incoming from the electrical assistance unit but there may be several other inputs from various relevant sensors in the steering system 1 or other sensors indicating driving or ambient conditions in order to control the electrical assistance unit.
  • the steering column 3 is connected at its end to an input shaft 8 of a hydraulic steering gear 9.
  • a hydraulic liquid pressure reservoir 10 in a first chamber 11 or second chamber 12.
  • the steering torque is transmitted from the steering gear 9 by a drop arm 13 to a steering arm 14 connected to a first steerable wheel 15 such that the first wheel 15 turns.
  • the first wheel 15 is mechanically connected to a link arrangement 16 such that the steering force is transmitted to a second steerable wheel 17 located on the same axle 18.
  • the invention is directed to the inclusion of an electrical assistance unit 4 in a power steering system comprising a hydraulic steering gear 9 and how this electrical assistance unit 4 is integrated in the power steering system 1 to cooperate with the hydraulic steering gear 4.
  • the electrical assistance unit 4 is located on the steering wheel column 3 in between the steering wheel 2 and the input shaft 8 of the steering gear 9.
  • FIG 2 is shown an enlarged view of the part of the steering column 3 comprising the electrical assistance unit 4.
  • the electrical assistance unit 4 enclosing the steering column 3.
  • the electrical assistance 4 includes an electric motor 19 having a rotor 20 and a stator 21.
  • the steering column 3 is divided in an upper part 22 which is fixedly connected to the steering wheel 2 (see figure 1) and a lower part 23 which is fixedly connected to the input shaft 8 of the steering gear 9 (see figure 1).
  • a torsion bar 24 located in between the upper part 22 and lower part 23 of the steering column 3 is a torsion bar 24 located.
  • the torsion bar 24 is further provided with a first angle sensor 25 close to its upper end, i.e.
  • the force should thus be decided to origin from the side which has the highest angular acceleration or velocity, i.e the force is decided to originate from the wheels if the angular acceleration or velocity is indicated higher from the second, lower angle sensor 26 than from the first, upper sensor 25 and if the first, upper sensor 25 indicates a higher angular speed or velocity than the second, lower sensor 26 is the turning force decided to originate from the steering wheel. If the magnitude, turning direction and origin of the torque is decided, an appropriate control signal may be sent to the electrical assistance unit 4.
  • the electrical assistance unit 4 may thus be helpful in both preventing or decreasing a torque from the wheels sensed in the steering wheel as well as providing an additional steering torque to the steering column in order to help in a steering action or creating a desired steering wheel feeling when turning.
  • angle sensors may be located at other locations, e.g one angle sensor at the steering wheel and another in the steering gear or at the steered wheels. It is neither important the kind of sensors used for this power steering system and other sensors for detecting the magnitude and direction of the torque and/or the steering angle may be used. Likewise, any kind of sensors or sensor system which may detect the origin of the force may be used instead of the sensor system described herein.
  • the above location of the electric motor provides a compact system which may be used without the feature of adapting the system to be able to counteract undesired turning forces from the wheels.
  • the electrical assistance unit could thus be suitable as an amplifier of the steering force from the steering wheel and be used art low velocities when ranging or parking a vehicle provided with the system or serve as a backup steering aid system which is active in case the hydraulic gear stop functioning.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Steering Control In Accordance With Driving Conditions (AREA)

Abstract

La présente invention concerne un système de direction assistée (1) comprenant un volant de direction (2) mécaniquement connecté à des roues directrices (15, 17) à travers une colonne directrice (3). Ledit système de direction assistée (1) comporte plus encore un mécanisme de direction hydraulique (9) adapté pour assurer un couple de direction supplémentaire aux roues directrices (15, 17) en dépendance de l'application du couple de direction à un arbre d'entrée (8) du mécanisme de direction hydraulique (9). Le système de direction assistée comporte également une unité d'assistance électrique (4) afin de fournir un couple de retournement à la colonne directrice (3). L'unité d'assistance électrique est commandée par une unité de commande (5) en dépendance des signaux d'entrée en provenance d'un détecteur de couple et d'un capteur d'angle. Afin d'assurer la contrôlabilité souhaitée du système de direction assistée, l'unité d'assistance électrique (4) est positionnée de façon à fournir un couple sur la colonne directrice (3) entre ledit mécanisme de direction hydraulique (9) et ledit volant de direction (2). Ladite disposition est particulièrement adaptée si le système de direction assistée (1) est prévu pour exercer des contre-forces de rotation sur la colonne directrice (3), et donc sur le volant de direction (2) connecté à celle-ci, qui résultent d'une rotation des roues indésirable en raison d'irrégularités sur la surface de la route.
PCT/SE2012/000014 2012-02-07 2012-02-07 Système de direction assistée WO2013119147A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/SE2012/000014 WO2013119147A1 (fr) 2012-02-07 2012-02-07 Système de direction assistée

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/SE2012/000014 WO2013119147A1 (fr) 2012-02-07 2012-02-07 Système de direction assistée

Publications (1)

Publication Number Publication Date
WO2013119147A1 true WO2013119147A1 (fr) 2013-08-15

Family

ID=48947816

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE2012/000014 WO2013119147A1 (fr) 2012-02-07 2012-02-07 Système de direction assistée

Country Status (1)

Country Link
WO (1) WO2013119147A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10005488B2 (en) 2015-12-18 2018-06-26 Ford Global Technologies, Llc Electrically controlled steering assistance actuator
EP3925859A1 (fr) * 2020-05-22 2021-12-22 Jtekt Corporation Dispositif de commande de moteur et système de direction
US11987299B2 (en) 2018-07-04 2024-05-21 Volvo Truck Corporation Steering gear assembly with multiple input shafts, remanufacturing kit, and remanufacturing methods

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6364869A (ja) * 1986-09-04 1988-03-23 Mazda Motor Corp 電動パワ−ステアリング装置
US5080186A (en) * 1988-06-15 1992-01-14 Zahnradfabrik Friedrichshafen, Ag. Servo-assisted steering system for motor vechicles
DE10320846A1 (de) * 2003-05-09 2004-12-02 Daimlerchrysler Ag Lenkungsvorrichtung für Kraftfahrzeuge
EP1637435A2 (fr) * 2004-09-17 2006-03-22 Delphi Technologies, Inc. Contrôle de position et de force pour direction avant active
EP1650106A2 (fr) * 2004-10-21 2006-04-26 Bayerische Motoren Werke Aktiengesellschaft Dispositif pour la réduction des vibrations en rotation d'un volant de direction dans un véhicule à moteur et son procédé de fonctionnement
US20070193817A1 (en) * 2006-01-31 2007-08-23 Walter Kogel Hydraulic power steering
DE102006051990A1 (de) * 2006-11-03 2008-05-08 Trw Automotive U.S. Llc, Livonia Closed-Center Lenksystem
EP1982896A2 (fr) * 2007-04-20 2008-10-22 Jtekt Corporation Appareil de direction assistée électrique
EP2070804A1 (fr) * 2006-10-03 2009-06-17 JTEKT Corporation Dispositif de direction de vehicule
WO2011148240A1 (fr) * 2010-05-24 2011-12-01 Toyota Jidosha Kabushiki Kaisha Système de direction et appareil de commande de direction

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6364869A (ja) * 1986-09-04 1988-03-23 Mazda Motor Corp 電動パワ−ステアリング装置
US5080186A (en) * 1988-06-15 1992-01-14 Zahnradfabrik Friedrichshafen, Ag. Servo-assisted steering system for motor vechicles
DE10320846A1 (de) * 2003-05-09 2004-12-02 Daimlerchrysler Ag Lenkungsvorrichtung für Kraftfahrzeuge
EP1637435A2 (fr) * 2004-09-17 2006-03-22 Delphi Technologies, Inc. Contrôle de position et de force pour direction avant active
EP1650106A2 (fr) * 2004-10-21 2006-04-26 Bayerische Motoren Werke Aktiengesellschaft Dispositif pour la réduction des vibrations en rotation d'un volant de direction dans un véhicule à moteur et son procédé de fonctionnement
US20070193817A1 (en) * 2006-01-31 2007-08-23 Walter Kogel Hydraulic power steering
EP2070804A1 (fr) * 2006-10-03 2009-06-17 JTEKT Corporation Dispositif de direction de vehicule
DE102006051990A1 (de) * 2006-11-03 2008-05-08 Trw Automotive U.S. Llc, Livonia Closed-Center Lenksystem
EP1982896A2 (fr) * 2007-04-20 2008-10-22 Jtekt Corporation Appareil de direction assistée électrique
WO2011148240A1 (fr) * 2010-05-24 2011-12-01 Toyota Jidosha Kabushiki Kaisha Système de direction et appareil de commande de direction

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10005488B2 (en) 2015-12-18 2018-06-26 Ford Global Technologies, Llc Electrically controlled steering assistance actuator
US11987299B2 (en) 2018-07-04 2024-05-21 Volvo Truck Corporation Steering gear assembly with multiple input shafts, remanufacturing kit, and remanufacturing methods
EP3925859A1 (fr) * 2020-05-22 2021-12-22 Jtekt Corporation Dispositif de commande de moteur et système de direction

Similar Documents

Publication Publication Date Title
EP2448805B1 (fr) Procédé et système pour assister un conducteur de véhicule pendant la conduite
US20190118853A1 (en) Feedback actuator for a steer-by-wire steering mechanism
US8818633B2 (en) Steering apparatus, and kickback determination apparatus
US8930082B2 (en) Steering method and steering system for an industrial truck
CN109415086B (zh) 进出弯道时具有不同阻尼的线控转向系统
WO2014102562A1 (fr) Procédé de commande d'un système de direction assistée pour un véhicule possédant deux essieux directeurs
WO2013119147A1 (fr) Système de direction assistée
JP2007516896A (ja) 動力操縦システム
US9545948B2 (en) Hydraulically assisted power steering system
US7508148B2 (en) Vehicle steering apparatus
EP1375299A1 (fr) Système de direction pour véhicules; procédé et dispositif pour commander la sensation de direction
US8838339B2 (en) Method for determining a torque on a steering train
US8509995B2 (en) Power steering device
JP2008074386A (ja) 自動車のステアリング特性改変方法
JP4506475B2 (ja) 車両用操舵制御装置
JP4349092B2 (ja) 車両のパワーステアリング制御装置
JP2009047542A (ja) トルク検出装置および操舵装置
WO2013132807A1 (fr) Dispositif de commande de direction de véhicule et procédé de commande de direction de véhicule
KR20230080553A (ko) Sbw 시스템의 조향 제어 장치
JP5310084B2 (ja) 車両用操舵装置、車両用操舵方法、車両用操舵装置付き車両
KR20110062119A (ko) 스티어 바이 와이어 시스템의 제어장치 및 방법
KR101903966B1 (ko) 차량자세제어를 위한 페일 세이프 제어 방법 및 장치
JP4575131B2 (ja) 車両操舵装置
US8005593B2 (en) Method for determining a torque on a steering train of a vehicle with dynamic drive system
KR101020538B1 (ko) 차량용 조타 토크 저감장치

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12868137

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12868137

Country of ref document: EP

Kind code of ref document: A1