CA1315207C - Steering system for motor vehicle - Google Patents
Steering system for motor vehicleInfo
- Publication number
- CA1315207C CA1315207C CA000593563A CA593563A CA1315207C CA 1315207 C CA1315207 C CA 1315207C CA 000593563 A CA000593563 A CA 000593563A CA 593563 A CA593563 A CA 593563A CA 1315207 C CA1315207 C CA 1315207C
- Authority
- CA
- Canada
- Prior art keywords
- motor vehicle
- steering
- travel
- road wheels
- steering system
- 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
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
- B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
- B62D5/005—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup means for generating torque on steering wheel or input member, e.g. feedback
- B62D5/006—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup means for generating torque on steering wheel or input member, e.g. feedback power actuated
-
- 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
- B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
- B62D6/002—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits computing target steering angles for front or rear wheels
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Steering Control In Accordance With Driving Conditions (AREA)
- Power Steering Mechanism (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A steering system for a motor vehicle having power steering means including an actuator for turning steerable read wheels of the motor vehicle includes a con-trol mechanism for eliminating a deviation between a desired direction of travel of the motor vehicle and an actual direction of travel of the motor vehicle, based on an output signal from a direction indicating mechanism which indicates the desired direction and the actual direction, and controls the power steering mechanism to turn the steerable road wheels up to the target turning angle.
A steering system for a motor vehicle having power steering means including an actuator for turning steerable read wheels of the motor vehicle includes a con-trol mechanism for eliminating a deviation between a desired direction of travel of the motor vehicle and an actual direction of travel of the motor vehicle, based on an output signal from a direction indicating mechanism which indicates the desired direction and the actual direction, and controls the power steering mechanism to turn the steerable road wheels up to the target turning angle.
Description
STEERING SYSTEM FOR MOTOR VEHICLE
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a steering system for use in a motor vehicle.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a steering system for use in a motor vehicle.
2. Description of the Relevant Art:
Conventional steering systems for motor vehicles or the like include mechanical components such as gears, links, and the like which operatively interconnect a steering wheel and steerable road wheels. Steering action of the steering wheel is transmitted via the mechanical components to the steerable road wheels to turn the road wheels through an angle'dependent on a steering angle Os of the steering wheel. In such a s,,teering system, the steering angle ~s represents a desired amount (or a desired angle) by which the motor vehicle is to be turned from a reference direction of the motor vehicle (i.e., a straight running direction of the motor vehicle). Therefore, where the steerlng angle Qs is zero, the motor vehicle runs along a straight course without changing its direction of travel.
When a motor vehicle 200 is to change lanes as shown in FIG. 6A of the accompanying drawings, the steering angle Os varies as shown in FIG. 6B while the resultant direction R2 of travel is the same as the initial direction Rl of travel. More specifically, when the motor vehicle 200 .~ -- 1 -- .
X
-, - ~ ' ', : , .. , . ~ , .
starts changing lanes, the steering wheel thereof (not shown~ is turned in one direction (to the right in FIG. 6B) from a neutral position (~s = o). When the motor vehicle 200 goes beyond a lane separating line L, the steering wheel is turned in the opposite direction (to the left) beyond the neutral position. When the motor vehicle 200 enters the desired other lane, the steering whsel is turned again in said one direction to allow the motor vehicle 200 to run straight, and then is returned to the neutral position.
When the motor vehicle 200 makes a 90-turn along a road bend around a corner as shown in FIG. 7A, the resultant direction R3 of travel of the motor vehicle 200 is angularly shifted 90 clockwise from the original direction R1 of travel. At this time, the steering angle Os varies as shown in FIG. 7B. At the start of making the turn, the steering wheel is turned in one direction (to the right in FIG. 7s) from the neutral position. When the motor vehicle 200 com-pletes the 90-turn, the steering wheel is turned in the opposite direction (to the left) back to the neutral position.
For steering the motor vehicle equipped with the above steering system, the driver may apply, as one steering input, a steering angle ~s as a basis for producing a turn-ing angle ~ of a steerable road wheel (e.g., a front wheel turning angle 6f), to the steering system. The behavior of the motor vehicle while it is making a turn is greatly -: :
affected by lateral motion (transverse motion) and yawing.
While the motor vehicle is making a stable turn, the lateral acceleration ~ of the motor vehicle, a yaw rate (yaw angular velocity~ r, and the radius R of the turning circle are related to the turning angle 6 (here, the front wheel turn-ing angle 6f) and the vehicle speed v as ollows:
Y 1 ~ Kf V2 ~ f (1) r = 1 + Kf v2 ~ ~f (2) R = (1 + Kf V2) ~6f ~ (3) where ~: the wheelbase, and Kf: the stability factor indicative of the response of the motor vehicle.
As can be ùnderstood from the above equations (1), (2), and (3), in order to get a desired turning behavior of the motor vehicle, the driver is required to achieve an appropriate turning angle ~f by giving a steering angle 9s) in view of the vehicle speed V.
When the speed of movement of the motor vehicle is high, and the lateral slip angle of the tires is large, the cornering forces produced by the tires become nonlinear. In such a case, the stability factor Kf is also varied as it is affected by the transient characteristics. Therefore, the driver is also required to turn the steering wheel while "X' ., taking into account such a change in the stability factor Kf.
SI~MMARY OF THE INVENTION
It is an object of the present invention to provide a steering system for steering a motor vehicle in a desired direction through a relatively simple steering action.
According to the present invention, there is pro-vided a steering system for a motor vehicle having power steering means including an actuator for turning steerable road wheels of the motor vehicle, said steering system comprising: direction indicating means for indicating a desired direction of travel of the motor vehicle with respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle; and control means responsive to an output signal from said direction indicating means and an output signal from said direction detecting means for controlling said power steering means to eliminate a devia-tion between said desired direction and said actual direc-tion based on said output signals.
According to the present invention, there is also provided a steering system for a motor vehicle having power steering means including an actuator for turning steerable road wheels of the motor vehicle, said steering system comprising: direction indicating means for indicating a desired direction of travel of the motor vehicle with _ ,1, _ V
respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle with respect to said refer-ence direction; target turning angle determining means responsive to an output signal from said direction indicat-ing means and an output signal from said direction detecting means for calculating a deviation between said desired direction and said actual direction based on said output signals, and for determining a target turning angle for the steerable road wheels dependent on said deviation; and con-trol means responsive to an output signal from said target turning angle determining means for controlling said power steering means to turn said steerable road wheels up to said target turning angle.
The above and further objects, details and advan-tages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a steer-ing system for a motor vehicle according to a preferred embodiment of the present invention;
FIG. 2 is a block diagram of the steering system;
FIG. 3 is a graph showing functional characteris-tics of the steering system;
V
FIG. 4 is a graph showing steering reactive force characteristics in the steering system;
FIGS. 5A and 5B are block diagrams showing func-tional blocks of the steering system;
FIGS. 6A through 6C are diagrams illustrating how a steering amount varies when a vehicle changes lanes; and FIGS. 7A through 7C are diagrams showing how a steering amount varies when a vehicle makes a turn.
DETAILE~ DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2, a steering system 10 for a motor vehicle according to the present invention has a steering wheel 11 (direction indicating means) fixedly mounted on the upper end of a steering shaft 12 rotatably supported on a vehicle body (not shown). The steering shaft 12 is mechanically.separate from steerable road wheels (not shown)~ and an encoder 13 and a reactive force generator 14 (reactive force applying means) including an electric motor (not shown) are mounted on the lower end of the steering shaft 12. The encoder 13 and the reactive force generator 14 are electrically connected to a controller 14 ~control means) comprising a microcomputer and other electronic devices. The encoder 13 detects the angular displacement of the steering shaft 12 and applies a signal indicative of a steering angle ~s to the controller 15. The electric motor of the reactive force generator 14 is controlled by the con-troller 15, as described later on, to apply a steering reac-X, tive force T to the steering shaft 12, i.e., the steeringwheel 11 as it is turned.
When the steering wheel 11 is turned, the steering reactive force T is applied to the steering wheel 11 by the reactive force generator 14. Since the steering wheel 11 is mechanically disconnected from the steerable road wheels, as described above, a self~aligning torque generated by the steerable road wheels when they are turned is not imposed on the steering wheel 11. In addition, the steering wheel 11 is not biased to rotate in either direction. As a consequence, the steering wheel 11 tends to stay in whatever position it may have been stopped by the driver of the motor vehicle.
In the motor vehicle equipped with the steering system 10, the steering angle ~s is regarded as being zero when the steerable road wheels (e.g., front road wheels) are directed in a stralght running dlrection. A front wheel steering angle ~f, for example, is varied dependent on a change in the steering angle ~s, as described below, to con-trol the direction of travel of the motor vehicle or its angle ~i.e., yaw angle ~) so as to achieve a desired direc-t~on or angla.
To the controller 15, there are electrically con-nected a speedometer 16, a yaw rate gyroscope 17 (direction detecting means), and a power steering mechanism PS. The speedometer 16 applies a signal indicative of a vehicle X
speed V to the controller lS. The yaw rate gyroscope 17 applies a signal representing a yaw rate r (yaw angular velocity r) of the motor vehicle to the controller 15. The power steering mechanism PS has an electric motor (not shown) for producing a steering force, and a gear mechanism (not shown) disposed between the electric motor and the steerable road wheels. The controller 15 energizes the electric motor of the power steering m~chanism PS to turn the steerable road wheels. The controller 15 processes sig-nals from the encoder 13, the speedometer 16, and the yaw rate gyroscope 17 according to a predetermined program, and controls the electric motor of the reactive force generator 14 to apply the steering reactive force to the steering wheel 11 and also controls the electric motor of the power steering mechanism PS to turn the steerable road wheels.
The power steering mechanism PS is disclosed in Japanese Patent Application No. 62-331084 (331084/1987) filed ~ecember 26, 1987 by the applicant.
Operation of the steering system 10 will be described below with reference to FIGS. 2, 3, and 4.
The controller 15, in particular, of the steering system 10 has functions as shown in FIG. 2. The steering angle ~s of the steering wheel 11 is basically representa-tive of a desired direction in which the motor vehicle should run, with respect to a reference direction of travel of the motor vehicl~ (i.e., the direction in which the motor vehicle runs at the time).
First, the steering angle ~s is multiplied by a gain constant K to determine a converted indicated angle K-~s. The yaw rate r is integrated to determine the yaw angle ~ of the motor vehicle from time to time. The yaw angle ~ is multiplied by a gain constant Kn to determine a converted running angle Kn-~ of the motor vehicle with respect to the reference direction. Then, the running angle Kn-~ is subtracted from the indicated angle K-as to calcu-late a deviation ae therebetween. The deviation ~e is mul-tiplied by a gain constant Ks to determine a target turning angle Ks~e for the steerable road wheels. Since the gain constant Ks for obtaining the target turning angle Ks-~e is a function of the vehicle speed V as described later on, the gain constant Ks varies with the vehicle speed V. If the vehicle speed v is constant, then the gain constant Ks is also constant, and the target turning angle Xs 3e is propor-tional to the deviation ~e. The steerable road wheels are turned up to the target turning angle Ks-~e by the power steering mechanism PS to cause the motor vehicle to make a turn. The turning motion of the motor veh1cle varies the yaw rate r and also the converted running angle Kn-~ of the motor vehicle which has been calculated by the aforesaid integrating and multiplying process. In this manner, the steerable road wheels are turned until the running angle Kn~ reaches the indicated angle K-~s while feeding back the converted running angle Kn-~ from time to time.
X
At the same time that the steerable road wheels are turned, the steering reactive force T is applied to the steering wheel 11 by the reactive force generator 14. The steering reactive force T is basically o* such a character-istic that it increases as the deviation ~e increases. The steering reactive force T also increases as the vehicle speed V increases, as described later.
Through the above functions, the steerable road wheels are continuously turned transitionally with a charac-teristic dependent on the deviation Oe, until finally the converted running angle Xn ~ of the motor vehicle reaches the indicated angle K ~s. Even if the turning behavior of the motor vehicle is temporarily affected by a disturbance such as a lateral wind or the like, the final running angle Kn-~ of the motor v.ehicle is reliably achieved. Therefore, the running angle Kn-~ of the motor vehicle can reach the indicated angle X as simply by turning the steering wheel 11 to give the desired indicated angle K 0s. As a conse~uence, the desired vehicle running angle K 0s can be attained through relatlvely simple steering action.
More specifically, when the motor vehicle having the steering system 10 changes lanes as shown in FIG. 6A, the steering angle Os varies as illustrated in FIG. 6C.
With the steering system 10, the lanes can be changed only by a steering action effected on one side of a temporary neutral position, and hence it is not necessary to effect a X
,~, ..~, ,, . : .
13~5207 steering action on both sides of the neutral position as with the conventional steering system as shown in FIG. 6s.
When the motor vehicle having the steering system lO makes a 90-turn as shown in FIG. 7A, the steering angle 0s varies as shown in FIG. 7C. With the steering system lO, when the turn is completed, the steering wheel 11 is kept in the position to which it has been turned, and does not need to be returned to the neutral position as with the conven-tional steering system as shown in FIG. 7B.
FIGS. 5A and 5B illustrate functional blocks of the steering system lO.
According to the functions shown in FIG. 2, the deviation 0e is determined as follows:
~ e = K-0s - Kn-~ --(4) The targe~ turning angle Ks-~e is determined on the basis of the deviation 0e.
All of the gain constants K, Kn, Ks, and Kp are functions of the vehicle speed V, and vary with the vehicle speed V.
By dividing both sides of the equation (4) by 0 the following equation is obtained:
0e/0s = K - Kn-~/~s --(4l) Inasmuch as the gain constants K, Kn are constant lf the vehicle speed V is constant, the lefthand side ~ei~s~ of the equation (4') indicates a normalized devia-tion or normalized input Nd, whereas the term ~/0s on the X
, `
righthand side indicates a normalized output No. From another standpoint, the lefthand side (-9e/~s) of the e~ua-tion (4') represents the sensitivity of the deviation ~e to the steering angle ~s, and the term ~/~s on the righthand side represents the sensitivity of the yaw angle ~ to the steering angle ~s.
For example, if the gain constants K, Kn in the equation (4l) are set so as to vary as described below, then characteristic curve groups Ga, Gb, and Gc indicated by the solid lines, the dot-and-dash lines, and the broken lines in FIG. 3 are obtained. It is assumed, however, that the vehi-cle speed V increases in increments.
Group Ga:
The gain constant K for the steering angle os: X =
1, i.e., it is cons~tant regardless of the vehicle speed v;
The gain constant Kn for the yaw angle ~: this increases in proportion to the vehicle speed V.
In the group Ga, the gain Kn for the yaw angle ~
increases in proportion to the vehicle speed V. Therefore, the higher the vehicle speed V, the higher the sensitivity with which the yaw angle ~ is detected. As a result, the rate of final change of the yaw angle ~ with respect to a unit steering angle is smaller as the vehicle speed V is higher.
With a characteristic curve LO achieved when K = 1 and Kn = O, since the gain constant Kn for the yaw angle . . ~ . .
is zero, the yaw angle ~ ls not fed back. Therefore, i~ the steering function is performed along the characteristic curve LO, the functional characteristics of the steering system lO are equivalent to those of the conventional steer-ing system in which the steering wheel and the steerable road wheels are mechanically interlinked.
Group Gb:
The gain constants K, Kn: soth decreas0 in inverse proportion to the vehicle speed V.
In the group Gb, the higher the vehicle speed V, the lower the sensitivity with which the steering angle ~s is applied and the sensitivity with which the yaw angle ~ is detected.
Group ~c:
The gain constant K: this decreases in inverse pro-portion to the vehicle spe~d V;
The gain constant Kn: K = 1, i.e., it is constant irrespective of the vehicle speed V.
In the group Gc, the gain K for the steering angle ~s increases in proportion to the vehicle speed V.
Consequently, the higher the vehicle speed V, the lower the sensitivity with which the steering angle ~s is applied. As a result, the rate of final change of the yaw angle ~ with respect to a unit steering angle is smaller as the vehicle speed V is higher.
As described above, the steering reactive force T
basically increases as the deviation ~e increases and also X
as the vehicle speed V increases. The steering reactive force T and the gain constant Kp are represented by func-tions T = Kp-f(~e) and Kp = g(V), respectively, where V
indicates the vehicle speed. The latter function has such a characteristic that the ~ain constant Kp increases as the vehicle speed V goes higher. Therefore, when the vehicle speed V is in a low range, a medium range, and a high range, the steering reactive force T increases respectively along characteristic curves Lt~, Ltm, Lth, shown in FIG. 4 as the deviation ~e increases. Since an adequate reactive force is applied to the steering wheel 11 dependent on the deviation ~e and the vehicle speed V, the steering action of the steering wheel 11 is stabilized, giving the driver a good steering feeling.
In the aboYe embodiment, the gain constants K, Kn, Kp are basically functions of the vehicle speed v only.
However, they may be functions of (i~ a steering amount such as a steering speed of the steering wheel 11, the deviation ~e, etc., or ~ii) a vehicle running condition such as the speed of a lateral wind applied to the motor vehicle, etc., or their combination. The present invention is applicable also to a steering system for a motor vehicle having steer-able front and rear road wheels.
A geomagnetism sensor may be employed in~tead of the yaw rate sensor 17 as means for detecting the actual direction of travel of the motor vehicle. Where such a geo-X
:. . . .
. .
, ~3152~7 magnetism sensor is used, the northward direction is used as an absolute reference direction.
Although there has been described what is at pre-sent considered to be the preferred embodiment of the pre-sent invention, it will be understood that the invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodi-ment is therefore to be considered in all aspects as illustrative, and not restrictive. The scope of the inven-tion is indicated by the appended claims rather than by the foregoing description.
~`
Conventional steering systems for motor vehicles or the like include mechanical components such as gears, links, and the like which operatively interconnect a steering wheel and steerable road wheels. Steering action of the steering wheel is transmitted via the mechanical components to the steerable road wheels to turn the road wheels through an angle'dependent on a steering angle Os of the steering wheel. In such a s,,teering system, the steering angle ~s represents a desired amount (or a desired angle) by which the motor vehicle is to be turned from a reference direction of the motor vehicle (i.e., a straight running direction of the motor vehicle). Therefore, where the steerlng angle Qs is zero, the motor vehicle runs along a straight course without changing its direction of travel.
When a motor vehicle 200 is to change lanes as shown in FIG. 6A of the accompanying drawings, the steering angle Os varies as shown in FIG. 6B while the resultant direction R2 of travel is the same as the initial direction Rl of travel. More specifically, when the motor vehicle 200 .~ -- 1 -- .
X
-, - ~ ' ', : , .. , . ~ , .
starts changing lanes, the steering wheel thereof (not shown~ is turned in one direction (to the right in FIG. 6B) from a neutral position (~s = o). When the motor vehicle 200 goes beyond a lane separating line L, the steering wheel is turned in the opposite direction (to the left) beyond the neutral position. When the motor vehicle 200 enters the desired other lane, the steering whsel is turned again in said one direction to allow the motor vehicle 200 to run straight, and then is returned to the neutral position.
When the motor vehicle 200 makes a 90-turn along a road bend around a corner as shown in FIG. 7A, the resultant direction R3 of travel of the motor vehicle 200 is angularly shifted 90 clockwise from the original direction R1 of travel. At this time, the steering angle Os varies as shown in FIG. 7B. At the start of making the turn, the steering wheel is turned in one direction (to the right in FIG. 7s) from the neutral position. When the motor vehicle 200 com-pletes the 90-turn, the steering wheel is turned in the opposite direction (to the left) back to the neutral position.
For steering the motor vehicle equipped with the above steering system, the driver may apply, as one steering input, a steering angle ~s as a basis for producing a turn-ing angle ~ of a steerable road wheel (e.g., a front wheel turning angle 6f), to the steering system. The behavior of the motor vehicle while it is making a turn is greatly -: :
affected by lateral motion (transverse motion) and yawing.
While the motor vehicle is making a stable turn, the lateral acceleration ~ of the motor vehicle, a yaw rate (yaw angular velocity~ r, and the radius R of the turning circle are related to the turning angle 6 (here, the front wheel turn-ing angle 6f) and the vehicle speed v as ollows:
Y 1 ~ Kf V2 ~ f (1) r = 1 + Kf v2 ~ ~f (2) R = (1 + Kf V2) ~6f ~ (3) where ~: the wheelbase, and Kf: the stability factor indicative of the response of the motor vehicle.
As can be ùnderstood from the above equations (1), (2), and (3), in order to get a desired turning behavior of the motor vehicle, the driver is required to achieve an appropriate turning angle ~f by giving a steering angle 9s) in view of the vehicle speed V.
When the speed of movement of the motor vehicle is high, and the lateral slip angle of the tires is large, the cornering forces produced by the tires become nonlinear. In such a case, the stability factor Kf is also varied as it is affected by the transient characteristics. Therefore, the driver is also required to turn the steering wheel while "X' ., taking into account such a change in the stability factor Kf.
SI~MMARY OF THE INVENTION
It is an object of the present invention to provide a steering system for steering a motor vehicle in a desired direction through a relatively simple steering action.
According to the present invention, there is pro-vided a steering system for a motor vehicle having power steering means including an actuator for turning steerable road wheels of the motor vehicle, said steering system comprising: direction indicating means for indicating a desired direction of travel of the motor vehicle with respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle; and control means responsive to an output signal from said direction indicating means and an output signal from said direction detecting means for controlling said power steering means to eliminate a devia-tion between said desired direction and said actual direc-tion based on said output signals.
According to the present invention, there is also provided a steering system for a motor vehicle having power steering means including an actuator for turning steerable road wheels of the motor vehicle, said steering system comprising: direction indicating means for indicating a desired direction of travel of the motor vehicle with _ ,1, _ V
respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle with respect to said refer-ence direction; target turning angle determining means responsive to an output signal from said direction indicat-ing means and an output signal from said direction detecting means for calculating a deviation between said desired direction and said actual direction based on said output signals, and for determining a target turning angle for the steerable road wheels dependent on said deviation; and con-trol means responsive to an output signal from said target turning angle determining means for controlling said power steering means to turn said steerable road wheels up to said target turning angle.
The above and further objects, details and advan-tages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a steer-ing system for a motor vehicle according to a preferred embodiment of the present invention;
FIG. 2 is a block diagram of the steering system;
FIG. 3 is a graph showing functional characteris-tics of the steering system;
V
FIG. 4 is a graph showing steering reactive force characteristics in the steering system;
FIGS. 5A and 5B are block diagrams showing func-tional blocks of the steering system;
FIGS. 6A through 6C are diagrams illustrating how a steering amount varies when a vehicle changes lanes; and FIGS. 7A through 7C are diagrams showing how a steering amount varies when a vehicle makes a turn.
DETAILE~ DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2, a steering system 10 for a motor vehicle according to the present invention has a steering wheel 11 (direction indicating means) fixedly mounted on the upper end of a steering shaft 12 rotatably supported on a vehicle body (not shown). The steering shaft 12 is mechanically.separate from steerable road wheels (not shown)~ and an encoder 13 and a reactive force generator 14 (reactive force applying means) including an electric motor (not shown) are mounted on the lower end of the steering shaft 12. The encoder 13 and the reactive force generator 14 are electrically connected to a controller 14 ~control means) comprising a microcomputer and other electronic devices. The encoder 13 detects the angular displacement of the steering shaft 12 and applies a signal indicative of a steering angle ~s to the controller 15. The electric motor of the reactive force generator 14 is controlled by the con-troller 15, as described later on, to apply a steering reac-X, tive force T to the steering shaft 12, i.e., the steeringwheel 11 as it is turned.
When the steering wheel 11 is turned, the steering reactive force T is applied to the steering wheel 11 by the reactive force generator 14. Since the steering wheel 11 is mechanically disconnected from the steerable road wheels, as described above, a self~aligning torque generated by the steerable road wheels when they are turned is not imposed on the steering wheel 11. In addition, the steering wheel 11 is not biased to rotate in either direction. As a consequence, the steering wheel 11 tends to stay in whatever position it may have been stopped by the driver of the motor vehicle.
In the motor vehicle equipped with the steering system 10, the steering angle ~s is regarded as being zero when the steerable road wheels (e.g., front road wheels) are directed in a stralght running dlrection. A front wheel steering angle ~f, for example, is varied dependent on a change in the steering angle ~s, as described below, to con-trol the direction of travel of the motor vehicle or its angle ~i.e., yaw angle ~) so as to achieve a desired direc-t~on or angla.
To the controller 15, there are electrically con-nected a speedometer 16, a yaw rate gyroscope 17 (direction detecting means), and a power steering mechanism PS. The speedometer 16 applies a signal indicative of a vehicle X
speed V to the controller lS. The yaw rate gyroscope 17 applies a signal representing a yaw rate r (yaw angular velocity r) of the motor vehicle to the controller 15. The power steering mechanism PS has an electric motor (not shown) for producing a steering force, and a gear mechanism (not shown) disposed between the electric motor and the steerable road wheels. The controller 15 energizes the electric motor of the power steering m~chanism PS to turn the steerable road wheels. The controller 15 processes sig-nals from the encoder 13, the speedometer 16, and the yaw rate gyroscope 17 according to a predetermined program, and controls the electric motor of the reactive force generator 14 to apply the steering reactive force to the steering wheel 11 and also controls the electric motor of the power steering mechanism PS to turn the steerable road wheels.
The power steering mechanism PS is disclosed in Japanese Patent Application No. 62-331084 (331084/1987) filed ~ecember 26, 1987 by the applicant.
Operation of the steering system 10 will be described below with reference to FIGS. 2, 3, and 4.
The controller 15, in particular, of the steering system 10 has functions as shown in FIG. 2. The steering angle ~s of the steering wheel 11 is basically representa-tive of a desired direction in which the motor vehicle should run, with respect to a reference direction of travel of the motor vehicl~ (i.e., the direction in which the motor vehicle runs at the time).
First, the steering angle ~s is multiplied by a gain constant K to determine a converted indicated angle K-~s. The yaw rate r is integrated to determine the yaw angle ~ of the motor vehicle from time to time. The yaw angle ~ is multiplied by a gain constant Kn to determine a converted running angle Kn-~ of the motor vehicle with respect to the reference direction. Then, the running angle Kn-~ is subtracted from the indicated angle K-as to calcu-late a deviation ae therebetween. The deviation ~e is mul-tiplied by a gain constant Ks to determine a target turning angle Ks~e for the steerable road wheels. Since the gain constant Ks for obtaining the target turning angle Ks-~e is a function of the vehicle speed V as described later on, the gain constant Ks varies with the vehicle speed V. If the vehicle speed v is constant, then the gain constant Ks is also constant, and the target turning angle Xs 3e is propor-tional to the deviation ~e. The steerable road wheels are turned up to the target turning angle Ks-~e by the power steering mechanism PS to cause the motor vehicle to make a turn. The turning motion of the motor veh1cle varies the yaw rate r and also the converted running angle Kn-~ of the motor vehicle which has been calculated by the aforesaid integrating and multiplying process. In this manner, the steerable road wheels are turned until the running angle Kn~ reaches the indicated angle K-~s while feeding back the converted running angle Kn-~ from time to time.
X
At the same time that the steerable road wheels are turned, the steering reactive force T is applied to the steering wheel 11 by the reactive force generator 14. The steering reactive force T is basically o* such a character-istic that it increases as the deviation ~e increases. The steering reactive force T also increases as the vehicle speed V increases, as described later.
Through the above functions, the steerable road wheels are continuously turned transitionally with a charac-teristic dependent on the deviation Oe, until finally the converted running angle Xn ~ of the motor vehicle reaches the indicated angle K ~s. Even if the turning behavior of the motor vehicle is temporarily affected by a disturbance such as a lateral wind or the like, the final running angle Kn-~ of the motor v.ehicle is reliably achieved. Therefore, the running angle Kn-~ of the motor vehicle can reach the indicated angle X as simply by turning the steering wheel 11 to give the desired indicated angle K 0s. As a conse~uence, the desired vehicle running angle K 0s can be attained through relatlvely simple steering action.
More specifically, when the motor vehicle having the steering system 10 changes lanes as shown in FIG. 6A, the steering angle Os varies as illustrated in FIG. 6C.
With the steering system 10, the lanes can be changed only by a steering action effected on one side of a temporary neutral position, and hence it is not necessary to effect a X
,~, ..~, ,, . : .
13~5207 steering action on both sides of the neutral position as with the conventional steering system as shown in FIG. 6s.
When the motor vehicle having the steering system lO makes a 90-turn as shown in FIG. 7A, the steering angle 0s varies as shown in FIG. 7C. With the steering system lO, when the turn is completed, the steering wheel 11 is kept in the position to which it has been turned, and does not need to be returned to the neutral position as with the conven-tional steering system as shown in FIG. 7B.
FIGS. 5A and 5B illustrate functional blocks of the steering system lO.
According to the functions shown in FIG. 2, the deviation 0e is determined as follows:
~ e = K-0s - Kn-~ --(4) The targe~ turning angle Ks-~e is determined on the basis of the deviation 0e.
All of the gain constants K, Kn, Ks, and Kp are functions of the vehicle speed V, and vary with the vehicle speed V.
By dividing both sides of the equation (4) by 0 the following equation is obtained:
0e/0s = K - Kn-~/~s --(4l) Inasmuch as the gain constants K, Kn are constant lf the vehicle speed V is constant, the lefthand side ~ei~s~ of the equation (4') indicates a normalized devia-tion or normalized input Nd, whereas the term ~/0s on the X
, `
righthand side indicates a normalized output No. From another standpoint, the lefthand side (-9e/~s) of the e~ua-tion (4') represents the sensitivity of the deviation ~e to the steering angle ~s, and the term ~/~s on the righthand side represents the sensitivity of the yaw angle ~ to the steering angle ~s.
For example, if the gain constants K, Kn in the equation (4l) are set so as to vary as described below, then characteristic curve groups Ga, Gb, and Gc indicated by the solid lines, the dot-and-dash lines, and the broken lines in FIG. 3 are obtained. It is assumed, however, that the vehi-cle speed V increases in increments.
Group Ga:
The gain constant K for the steering angle os: X =
1, i.e., it is cons~tant regardless of the vehicle speed v;
The gain constant Kn for the yaw angle ~: this increases in proportion to the vehicle speed V.
In the group Ga, the gain Kn for the yaw angle ~
increases in proportion to the vehicle speed V. Therefore, the higher the vehicle speed V, the higher the sensitivity with which the yaw angle ~ is detected. As a result, the rate of final change of the yaw angle ~ with respect to a unit steering angle is smaller as the vehicle speed V is higher.
With a characteristic curve LO achieved when K = 1 and Kn = O, since the gain constant Kn for the yaw angle . . ~ . .
is zero, the yaw angle ~ ls not fed back. Therefore, i~ the steering function is performed along the characteristic curve LO, the functional characteristics of the steering system lO are equivalent to those of the conventional steer-ing system in which the steering wheel and the steerable road wheels are mechanically interlinked.
Group Gb:
The gain constants K, Kn: soth decreas0 in inverse proportion to the vehicle speed V.
In the group Gb, the higher the vehicle speed V, the lower the sensitivity with which the steering angle ~s is applied and the sensitivity with which the yaw angle ~ is detected.
Group ~c:
The gain constant K: this decreases in inverse pro-portion to the vehicle spe~d V;
The gain constant Kn: K = 1, i.e., it is constant irrespective of the vehicle speed V.
In the group Gc, the gain K for the steering angle ~s increases in proportion to the vehicle speed V.
Consequently, the higher the vehicle speed V, the lower the sensitivity with which the steering angle ~s is applied. As a result, the rate of final change of the yaw angle ~ with respect to a unit steering angle is smaller as the vehicle speed V is higher.
As described above, the steering reactive force T
basically increases as the deviation ~e increases and also X
as the vehicle speed V increases. The steering reactive force T and the gain constant Kp are represented by func-tions T = Kp-f(~e) and Kp = g(V), respectively, where V
indicates the vehicle speed. The latter function has such a characteristic that the ~ain constant Kp increases as the vehicle speed V goes higher. Therefore, when the vehicle speed V is in a low range, a medium range, and a high range, the steering reactive force T increases respectively along characteristic curves Lt~, Ltm, Lth, shown in FIG. 4 as the deviation ~e increases. Since an adequate reactive force is applied to the steering wheel 11 dependent on the deviation ~e and the vehicle speed V, the steering action of the steering wheel 11 is stabilized, giving the driver a good steering feeling.
In the aboYe embodiment, the gain constants K, Kn, Kp are basically functions of the vehicle speed v only.
However, they may be functions of (i~ a steering amount such as a steering speed of the steering wheel 11, the deviation ~e, etc., or ~ii) a vehicle running condition such as the speed of a lateral wind applied to the motor vehicle, etc., or their combination. The present invention is applicable also to a steering system for a motor vehicle having steer-able front and rear road wheels.
A geomagnetism sensor may be employed in~tead of the yaw rate sensor 17 as means for detecting the actual direction of travel of the motor vehicle. Where such a geo-X
:. . . .
. .
, ~3152~7 magnetism sensor is used, the northward direction is used as an absolute reference direction.
Although there has been described what is at pre-sent considered to be the preferred embodiment of the pre-sent invention, it will be understood that the invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodi-ment is therefore to be considered in all aspects as illustrative, and not restrictive. The scope of the inven-tion is indicated by the appended claims rather than by the foregoing description.
~`
Claims (9)
1. A steering system for a motor vehicle having power steering means including an actuator for turning steerable road wheels of the motor vehicle, said steering system comprising:
direction indicating means for indicating a desired direction of travel of the motor vehicle with respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle; and control means responsive to an output signal from said direction indicating means and an output signal from said direction detecting means for controlling said power steering means to eliminate a deviation between said desired direction and said actual direction based on said output signals;
said direction indicating means including a steering wheel mechanically separate from said steerable road wheels and which is not biased to rotate in either direction so the steering wheel remains in a position to which it has been moved by an operator after turn of the vehicle has been completed and the wheels have returned to a neutral position; and said direction indicating means being operable to indicate a desired absolute direction in which said motor vehicle is to travel.
direction indicating means for indicating a desired direction of travel of the motor vehicle with respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle; and control means responsive to an output signal from said direction indicating means and an output signal from said direction detecting means for controlling said power steering means to eliminate a deviation between said desired direction and said actual direction based on said output signals;
said direction indicating means including a steering wheel mechanically separate from said steerable road wheels and which is not biased to rotate in either direction so the steering wheel remains in a position to which it has been moved by an operator after turn of the vehicle has been completed and the wheels have returned to a neutral position; and said direction indicating means being operable to indicate a desired absolute direction in which said motor vehicle is to travel.
2. A steering system according to claim 1, further comprising indicated direction gain control means for varying a gain of the output signal from said direction indicating means.
3. A steering system according to claim 2, wherein said indicated direction gain control means comprises means for controlling said gain so as to reduce the gain in inverse proportion to a speed of travel of the motor vehicle.
4. A steering system according to claim 1, further comprising detection gain control means for varying a gain of the output signal from said direction detecting means.
5. A steering system according to claim 4, wherein said detection gain control means comprises means for controlling said gain so as to increase the gain in proportion to a speed of travel of the motor vehicle.
6. A steering system according to claim 1 further comprising:
resistive force applying means for applying a steering resistive force to said direction indicating means; and resistive force control means for controlling said resistive force applying means to apply the steering resistive force which increases in proportion to said deviation between said desired direction and said actual direction.
resistive force applying means for applying a steering resistive force to said direction indicating means; and resistive force control means for controlling said resistive force applying means to apply the steering resistive force which increases in proportion to said deviation between said desired direction and said actual direction.
7. A steering system according to claim 6, wherein said resistive fore control means comprises means for controlling said resistive force applying means to increase a rate of change of said steering resistive force with respect to said deviation in proportion to a speed of travel of the motor vehicle.
8. A steering system for a motor vehicle having power steering means including an actuator for turning steerable road wheels of the motor vehicle, said steering system comprising:
direction indicating means for indicating a desired direction of travel of the motor vehicle with respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle with respect to said reference direction;
target turning angle determining means responsive to an output signal from said direction indicating means and an output signal from said direction detecting means for calculating a deviation between said desired direction and said actual direction based on said output signals, and for determining a target turning angle for the steerable road wheels dependent on said deviation; and control means responsive to an output signal from said target turning angle determining means for controlling said power steering means to turn said steerable road wheels up to said target turning angle;
said direction indicating means including a steering wheel mechanically separate from said steerable road wheels and which is not biased to rotate in either direction so the steering wheel remains in a position to which it has been moved by an operator after turn of the vehicle has been completed and the wheels have returned to a neutral position; and said direction indicating means being operable to indicate a desired absolute direction in which said motor vehicle is to travel.
direction indicating means for indicating a desired direction of travel of the motor vehicle with respect to a reference direction of the motor vehicle;
direction detecting means for detecting an actual direction of travel of the motor vehicle with respect to said reference direction;
target turning angle determining means responsive to an output signal from said direction indicating means and an output signal from said direction detecting means for calculating a deviation between said desired direction and said actual direction based on said output signals, and for determining a target turning angle for the steerable road wheels dependent on said deviation; and control means responsive to an output signal from said target turning angle determining means for controlling said power steering means to turn said steerable road wheels up to said target turning angle;
said direction indicating means including a steering wheel mechanically separate from said steerable road wheels and which is not biased to rotate in either direction so the steering wheel remains in a position to which it has been moved by an operator after turn of the vehicle has been completed and the wheels have returned to a neutral position; and said direction indicating means being operable to indicate a desired absolute direction in which said motor vehicle is to travel.
9. A steering system for a motor vehicle having steerable road wheels, comprising:
direction detecting means for detecting an actual direction of travel of the motor vehicle and producing a detected signal indicating said actual direction;
steering means mechanically separate from said steerable road wheels for producing an indication signal indicating a desired absolute direction of travel in which said motor vehicle is to travel, said steering means including a steering wheel which is turned by an operator to produce said indication signal, said steering wheel not being biased in either direction so that it remains in a position to which it has been turned after turn of the vehicle has been completed and the road wheels have returned to a neutral position; and control means responsive to said detected signal from said direction detecting means and said indication signal from said steering means for transitionally turning said steerable road wheels to bring the resultant actual direction of travel of the motor vehicle into agreement with said desired direction based on said detected and indication signals.
direction detecting means for detecting an actual direction of travel of the motor vehicle and producing a detected signal indicating said actual direction;
steering means mechanically separate from said steerable road wheels for producing an indication signal indicating a desired absolute direction of travel in which said motor vehicle is to travel, said steering means including a steering wheel which is turned by an operator to produce said indication signal, said steering wheel not being biased in either direction so that it remains in a position to which it has been turned after turn of the vehicle has been completed and the road wheels have returned to a neutral position; and control means responsive to said detected signal from said direction detecting means and said indication signal from said steering means for transitionally turning said steerable road wheels to bring the resultant actual direction of travel of the motor vehicle into agreement with said desired direction based on said detected and indication signals.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63-61670 | 1988-03-14 | ||
| JP63061670A JPH0686222B2 (en) | 1988-03-14 | 1988-03-14 | Steering device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1315207C true CA1315207C (en) | 1993-03-30 |
Family
ID=13177904
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000593563A Expired - Fee Related CA1315207C (en) | 1988-03-14 | 1989-03-14 | Steering system for motor vehicle |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4984646A (en) |
| EP (1) | EP0333108B1 (en) |
| JP (1) | JPH0686222B2 (en) |
| AT (1) | ATE114563T1 (en) |
| CA (1) | CA1315207C (en) |
| DE (1) | DE68919491T2 (en) |
Families Citing this family (36)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4009400A1 (en) * | 1990-03-23 | 1991-09-26 | Porsche Ag | ACTUATOR FOR A CYBERNETIC STEERING |
| US5067576A (en) * | 1990-08-15 | 1991-11-26 | Ford Motor Company | Variable effort steering system |
| FR2678884B1 (en) * | 1991-07-12 | 1996-08-14 | Sextant Avionique | ROTARY ACTUATOR CAPABLE OF GENERATING ON THE HANDWHEEL OF A CONTROL SYSTEM, A VARIABLE RESISTANT TORQUE ACCORDING TO ADAPTIVE LAW. |
| JPH05105100A (en) * | 1991-09-27 | 1993-04-27 | Honda Motor Co Ltd | Vehicle steering system |
| DE4202699A1 (en) * | 1992-01-31 | 1993-08-05 | Bosch Gmbh Robert | DEVICE FOR CONTROLLING THE STEERING ANGLE |
| JP3098124B2 (en) * | 1992-11-05 | 2000-10-16 | 本田技研工業株式会社 | Control method of rear wheel steering device |
| DE4304664C2 (en) * | 1993-02-16 | 2000-04-06 | Daimler Chrysler Ag | Control device, in particular steering for motor vehicles |
| JP3229074B2 (en) * | 1993-06-04 | 2001-11-12 | 本田技研工業株式会社 | Vehicle steering system |
| JP3172333B2 (en) * | 1993-06-04 | 2001-06-04 | 本田技研工業株式会社 | Vehicle steering system |
| JP3229077B2 (en) * | 1993-06-29 | 2001-11-12 | 本田技研工業株式会社 | Vehicle steering system |
| US5668721A (en) * | 1995-10-02 | 1997-09-16 | General Motors Corporation | Electric power steering motor control |
| US5719766A (en) * | 1995-10-02 | 1998-02-17 | General Motors Corporation | Electric power steering control |
| US5704446A (en) * | 1995-10-02 | 1998-01-06 | General Motors Corporation | Electric power steering control |
| US5668722A (en) * | 1995-10-02 | 1997-09-16 | General Motors Corporation | Electric power steering control |
| DE19546943C1 (en) * | 1995-12-15 | 1997-06-19 | Daimler Benz Ag | Steering for non-track-bound vehicles |
| DE19600139C1 (en) * | 1996-01-04 | 1997-05-07 | Daimler Benz Ag | Control element arrangement for controlling the steering angle of a motor vehicle |
| DE19625503C1 (en) * | 1996-06-26 | 1997-10-09 | Daimler Benz Ag | Electric power-assisted steering device for motor vehicle |
| JPH10203393A (en) * | 1997-01-21 | 1998-08-04 | Koyo Seiko Co Ltd | Vehicular steering device |
| DE19702313C1 (en) * | 1997-01-23 | 1998-04-02 | Daimler Benz Ag | Control device for controlling steering angle of motor vehicle |
| JP3493568B2 (en) * | 1997-02-12 | 2004-02-03 | 光洋精工株式会社 | Car steering system |
| US6141605A (en) * | 1999-06-25 | 2000-10-31 | Ford Global Technologies, Inc. | Determining the direction of travel of an automotive vehicle from yaw rate and relative steering wheel angle |
| EP1125826A3 (en) * | 2000-02-11 | 2003-01-08 | Delphi Technologies, Inc. | Control of independent steering actuators to improve vehicle stability and stopping |
| US6581966B2 (en) * | 2001-01-05 | 2003-06-24 | Ford Global Technologies, Inc. | Twin axis steering wheel system |
| US20020180608A1 (en) | 2001-05-04 | 2002-12-05 | Sphericon Ltd. | Driver alertness monitoring system |
| US7083025B2 (en) * | 2002-06-03 | 2006-08-01 | Delphi Technologies, Inc. | Method for implementing vehicle stability enhancement reference models for active steer systems |
| JP4147836B2 (en) | 2002-06-21 | 2008-09-10 | 株式会社ジェイテクト | Vehicle steering system |
| JP4205442B2 (en) | 2003-01-16 | 2009-01-07 | 本田技研工業株式会社 | Steering device |
| JP4398300B2 (en) * | 2004-05-19 | 2010-01-13 | 本田技研工業株式会社 | Vehicle steering device |
| JP4881631B2 (en) * | 2006-02-28 | 2012-02-22 | 本田技研工業株式会社 | Vehicle steering device |
| US7599774B2 (en) * | 2006-03-10 | 2009-10-06 | Gm Global Technology Operations, Inc. | Method and system for adaptively compensating closed-loop front-wheel steering control |
| US7933701B2 (en) * | 2006-12-28 | 2011-04-26 | Caterpillar Inc. | Closed-loop motion-control system using error to modify gain |
| US8131424B2 (en) * | 2008-01-16 | 2012-03-06 | GM Global Technology Operations LLC | Methods and systems for calculating yaw gain for use in controlling a vehicle |
| JP4486158B1 (en) * | 2009-10-14 | 2010-06-23 | 株式会社近藤鐵工所 | Steering device |
| JP5800194B2 (en) * | 2011-11-08 | 2015-10-28 | 株式会社ジェイテクト | Vehicle steering system and cargo handling vehicle |
| KR20170057313A (en) | 2014-09-09 | 2017-05-24 | 토르벡 인코포레이티드 | Methods and apparatus for monitoring alertness of an individual utilizing a wearable device and providing notification |
| CA3014812A1 (en) | 2016-02-18 | 2017-08-24 | Curaegis Technologies, Inc. | Alertness prediction system and method |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3011579A (en) * | 1959-01-08 | 1961-12-05 | Gen Motors Corp | Steering system |
| GB2090675B (en) * | 1978-01-19 | 1982-12-15 | Lely Nv C Van Der | A land vehicle having automatic steering control |
| JPS59111508A (en) * | 1982-12-16 | 1984-06-27 | Agency Of Ind Science & Technol | Automatic car guiding method using point follow-up system |
| US4557342A (en) * | 1983-05-20 | 1985-12-10 | Trw Inc. | Hydraulic apparatus |
| JPS6067264A (en) * | 1983-09-24 | 1985-04-17 | Jidosha Kiki Co Ltd | Power steering apparatus |
| JPS60161255A (en) * | 1984-01-31 | 1985-08-22 | Nissan Motor Co Ltd | Auxiliary steering apparatus for car |
| JPH0615340B2 (en) * | 1985-12-27 | 1994-03-02 | 日産自動車株式会社 | Steering reaction force control device |
| JPH0667738B2 (en) * | 1986-12-09 | 1994-08-31 | 東海テイ−ア−ルダブリユ−株式会社 | Electric power steering device with electric motor braking function |
| JPS63180563A (en) * | 1987-01-22 | 1988-07-25 | Honda Motor Co Ltd | Electromotive power steering device |
| US4860844A (en) * | 1988-04-29 | 1989-08-29 | Eaton Corporation | Power steering system |
| US4865144A (en) * | 1988-04-29 | 1989-09-12 | Eaton Corporation | Power steering system having simulated torque sensor |
-
1988
- 1988-03-14 JP JP63061670A patent/JPH0686222B2/en not_active Expired - Fee Related
-
1989
- 1989-03-13 AT AT89104435T patent/ATE114563T1/en not_active IP Right Cessation
- 1989-03-13 EP EP89104435A patent/EP0333108B1/en not_active Expired - Lifetime
- 1989-03-13 DE DE68919491T patent/DE68919491T2/en not_active Expired - Fee Related
- 1989-03-14 US US07/323,496 patent/US4984646A/en not_active Expired - Fee Related
- 1989-03-14 CA CA000593563A patent/CA1315207C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE68919491D1 (en) | 1995-01-12 |
| US4984646A (en) | 1991-01-15 |
| DE68919491T2 (en) | 1995-04-06 |
| EP0333108A2 (en) | 1989-09-20 |
| JPH0686222B2 (en) | 1994-11-02 |
| ATE114563T1 (en) | 1994-12-15 |
| EP0333108B1 (en) | 1994-11-30 |
| EP0333108A3 (en) | 1992-09-23 |
| JPH01233170A (en) | 1989-09-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1315207C (en) | Steering system for motor vehicle | |
| CN111108035B (en) | Method and system for controlling lane keeping of a vehicle | |
| US4794539A (en) | Propulsion control using steering angle and vehicle speed to determine tolerance range | |
| US7957867B2 (en) | Steering system of vehicle | |
| US4703822A (en) | Front and rear wheel steering device for a vehicle | |
| US5018594A (en) | Rear-wheel steering system for four-wheel steering vehicle | |
| EP1800994B1 (en) | Controller of electric power steering device of vehicle in which steered wheels are driven | |
| JP5170496B2 (en) | Electric power steering device | |
| US6112845A (en) | Reactive steering control system | |
| KR101413854B1 (en) | Vehicle steering control system comprising no mechanical linkage between the steering wheel and the steered wheels | |
| US20040016294A1 (en) | Apparatus for determining linearity of tire characteristic | |
| GB2259892A (en) | Motor vehicle steering system | |
| US7315772B2 (en) | Motion control apparatus and method for automotive vehicle | |
| US6345218B1 (en) | Vehicle steering control system based on vehicle body side slip angle | |
| US6148951A (en) | Reactive steering control system | |
| US6637543B2 (en) | Oversteer control for a motor vehicle | |
| US20160129932A1 (en) | Steering system for wheeled land vehicle | |
| US4971173A (en) | Rear-wheel steering system of a motor vehicle | |
| JP2717676B2 (en) | Rear wheel steering control device for vehicle | |
| JP3487980B2 (en) | Control method of front and rear wheel steering vehicle | |
| JP3013640B2 (en) | Electric motor driven four-wheel steering system | |
| JP2598787B2 (en) | Rear wheel steering system for vehicles | |
| JP2619658B2 (en) | Control method of four-wheel steering device for automobile | |
| JPH0220476A (en) | Steering device for rear wheel of vehicle | |
| JPH06156301A (en) | Rear wheel steering angle control device for four wheel steering vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |