JPH0834353A - Steering device for vehicle - Google Patents

Abstract

PURPOSE:To improve the operability of a steering device having a joy stick by controlling a steering mechanism so that the ratio of the actual steering angle of a steering wheel to the manipulated variable of the joy stick may become the smaller, the higher vehicle speed is. CONSTITUTION:At an electronic controller (controller) 26, the manipulated variable signal of a joy stick 24 is inputted from a steering angle sensor 30 with a right turning direction as positive, and a vehicle speed signal is inputted from a vehicle speed sensor 38, and in addition an axis power signal to act on a rack bar is inputted from an axis power sensor 40 provided at a tie-rod 18R. The controller 26 operates, on the basis of the manipulated variable signal of the inputted joy stick 24 and vehicle speed signal, the rotary angle of a steering motor 20, and outputs to the steering motor 20 a control signal in regard to the calculated rotary angle, and controls the turning angles of front wheels 12L, 12R. At this time, control is made so that the higher vehicle speed is, the ratio of the actual steering angle of a steering wheel to a joy stick manipulated variable may become the smaller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device for a vehicle such as an automobile, and more particularly to a steering device having a joystick as steering input means.

[0002]

2. Description of the Related Art A steering wheel is generally used as a steering input means in a steering device for a vehicle such as an automobile. However, as described in, for example, US Pat. No. 5,086,870, one end is a steering wheel. 2. Description of the Related Art A vehicle steering system using a joystick, which is pivotally supported by a vehicle body and is pivotally operated at the other end by a driver of a vehicle as steering input means, has been already known.

In general, the rotation angle range of the steering wheel is 360 ° or more, whereas the pivot angle range of the joystick is much smaller than this range, which corresponds to the joystick required to steer the steered wheels at the same angle. Since the steering input amount can be much smaller than in the case of a steering wheel, the joystick type steering device can significantly reduce the driver's steering operation burden and enable one-handed driving. become.

[0004]

However, in the conventional joystick type steering device as described above, the ratio of the actual steering angle of the steered wheels to the operation amount of the joystick is much larger than that of the steering wheel. Therefore, there is a problem that a driver who is accustomed to steering with the steering wheel feels uncomfortable and has poor operability, and the steering stability of the vehicle is likely to be deteriorated due to excessive cutting of the steering wheel. Further, when the joystick is provided on either the left or right side of the driver's seat as described in the above-mentioned US patent publication, the joystick cannot be held by the left and right hands, and the dominant arm cannot be used depending on the driver. Even in that respect, the operability is poor.

The present invention has been made in view of the above-described problems in the conventional joystick type steering device. The main problem to be solved by the present invention is the operability of the steering device having a joystick. Is to be improved as compared with the conventional one.

[0006]

According to the present invention, the main problems as described above are as follows. (1) A joystick that can be pivoted over a predetermined angle range, and an operation amount detection for detecting an operation amount of the joystick. In a vehicle steering system having means and a steering mechanism for steering a steered wheel in accordance with an operation amount of the joystick, a vehicle speed detection means and an actual steering of the steered wheel with respect to an operation amount of the joystick as the vehicle speed increases. A vehicle steering device (construction according to claim 1), comprising: a control means for controlling the steering mechanism so as to reduce the angular ratio, (2) a joystick and a steering wheel, and the joystick and An operation amount detecting means for detecting an operation amount of the steering wheel, and steering according to the operation amount of the joystick or the steering wheel. In a vehicle steering system having a steering mechanism for steering a vehicle, a changeover switch for selecting a joystick or a steering wheel as effective steering input means, and the operation amount of the steering input means selected by the changeover switch is substantially equal to And a switching control means for executing actual switching of the steering input means when a value corresponding to the actual steering angle of the steered wheels is reached (configuration of claim 2). (3) A vehicle having a joystick capable of pivoting over a predetermined angle range, operation amount detection means for detecting an operation amount of the joystick, and a steering mechanism for steering a steered wheel in accordance with the operation amount of the joystick. In the steering device for vehicle, a plurality of the joysticks are provided, and the joysticks are configured to interlock with each other. A vehicle steering device characterized by the above (claim 3), or (4) a joystick and a steering wheel, an operation amount detecting means for detecting an operation amount of the joystick and the steering wheel, and an operation amount of the joystick or the steering wheel. In a vehicle steering system having a steering mechanism for steering steered wheels according to the above, a switch for selecting a joystick or a steering wheel as effective steering input means, and a steering input means not selected by the switch are substantially provided. And a switching control for executing an actual switching of the steering input means when the operation amount of the steering input means which is still effective after the switching switch is operated becomes substantially zero. A vehicle steering system characterized by having means Achieved by the rudder.

[0007]

According to the above configuration (1), the higher the vehicle speed, the smaller the ratio of the actual steering angle of the steered wheels to the operation amount of the joystick. Therefore, in the low vehicle speed range, the steered wheel with respect to the operation amount of the joystick is reduced. The actual steering angle ratio is relatively high to maintain good steering sensitivity, and in high vehicle speed range, steering sensitivity is reduced to prevent over-wheeling of the steered wheels and perform delicate steering. This makes it possible to improve the operability of the steering device and the steering stability of the vehicle during high-speed traveling, as compared with the related art.

Further, according to the above configuration (2), the driver can select the joystick or the steering wheel as an effective steering input means by operating the changeover switch, and is not accustomed to the operation of the joystick. It is possible to avoid the driver from feeling uncomfortable and disadvantageous. Further, since the actual switching of the steering input means is executed when the operation amount of the steering input means selected by the changeover switch becomes a value substantially corresponding to the actual steering angle of the steered wheels, the steering input means is switched. It is possible to reliably prevent hunting when the steering wheel is turned and smoothly switch the steering input means.

Further, according to the above configuration (3), since a plurality of joysticks are provided and the joysticks are configured to interlock with each other, the driver operates the corresponding joysticks with both hands as necessary. It becomes possible to change or hold the left and right hands, and the driver can always use the dominant arm regardless of right-handed or left-handed, which improves the operability of the steering device compared to the past, In addition, the driver's steering fatigue is reduced.

Further, according to the above configuration (4), since the driver can select the joystick or the steering wheel as an effective steering input means by operating the changeover switch, he is not accustomed to the operation of the joystick. It is possible to avoid the driver from feeling uncomfortable and disadvantageous. Further, the steering input means not selected by the changeover switch is substantially positioned at the neutral position, and the actual changeover of the steering input means is caused by the operation amount of the steering input means which is still effective after the changeover switch is operated. Since it is executed when the steering input means is changed to 0, it is possible to reliably prevent hunting when the steering input means is switched, and to smoothly switch the steering input means. Since it is not necessary to compare the operation amount with the value corresponding to the actual steering angle of the steered wheels, that is, the operation amount of the steering input means that is still valid at present, the switching control of the steering input means becomes simple.

[0011]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing a first embodiment of a steering device according to the present invention, and FIG. 2 is a perspective view showing the joystick shown in FIG.

In FIG. 1, reference numeral 10 denotes a rack-and-pinion type steering device, and 12L and 12R respectively denote left and right front wheels as steering wheels. The steering device 10 has a generally well-known structure in the related art, and includes a rack bar housing 14 that reciprocally supports a rack bar extending in the lateral direction of the vehicle, which is not shown in the drawing, and meshes with the rack bar. And a pinion housing 16 integrally formed with the rack bar housing 14 for rotatably supporting a pinion (not shown).

Inner ends of tie rods 18L and 18R are pivotally attached to both ends of the rack bar by ball joints not shown in the figure, and outer ends of tie rods 18L and 18R are not shown in the figure. Joints are pivotally attached to the knuckle arms of the left front wheel 12L and the right front wheel 12R, respectively. The shaft 22 of the steering motor 20 is integrally connected to the pinion.
The motor 20 is controlled by the electronic control unit 26 according to the operation amount of the joystick 24 by the driver. Therefore, the stepping motor is controlled so that the rotation angle is accurately controlled according to the command signal from the electronic control unit. A motor such as

Although not shown in detail in FIG. 2, when the joystick 24 is pivoted left and right, the steering shaft 28 rotates integrally therewith, but the joystick 24 is pivoted back and forth. Is also pivotally attached to the steering shaft so that the steering shaft does not move in the front-rear direction. The steering shaft 28 is provided with a steering angle sensor 30 and a reaction force adding device 32. The steering angle sensor 30 detects the operation amount θjs of the joystick 24 by detecting the rotation angle of the steering shaft 28, and the reaction force addition device 32 is in a direction opposite to the rotation direction of the joystick 24 due to electromagnetic force or spring force and electromagnetic force. The steering reaction force torque Tjs is given to the steering shaft 28.

In the embodiment shown in the drawings, the joystick 24 has an integral stopper arm 34, and a cable connected to a throttle valve driving link is provided at the tip of the stopper arm 34, which is not shown in the figure. Are connected. Mechanical stoppers 36L and 36R are provided on both the left and right sides of the stopper arm, and the horizontal pivoting angle of the joystick is limited by the mechanical stopper to a predetermined range (θml to θmr). As will be described later, when the joystick 24 is pivoted in the left-right direction, the left front wheel 12L and the right front wheel 12R are steered in the left-turning direction and the right-turning direction, respectively, and when the joystick is pivoted in the front-rear direction, the vehicle decelerates and Acceleration is set to take place.

A signal indicating the operation amount θjs of the joystick 24 is input to the electronic control unit 26 from the steering angle sensor 30 with the right-turning direction being positive, and the vehicle speed sensor 38 outputs the vehicle speed Vjs.
Is input, and a signal indicating the axial force F acting on the rack bar is input from the axial force sensor 40 provided on the tie rod 18R. Although not shown in detail in FIG. 2, the electronic control unit 26 has a microcomputer having a CPU, a RAM, a ROM, an input / output port unit, and a drive circuit, and the ROM is the flow chart shown in FIG. Also, the maps corresponding to the graphs shown in FIGS. 4 and 5 are stored.

Next, the operation of the illustrated first embodiment will be described with reference to the flow chart shown in FIG. 3 and the graphs shown in FIGS. The control according to this flowchart is started by closing an ignition switch, which is not shown in the figure, and ended by opening the ignition switch.

First, in step 10, the steering angle sensor 3
Steering angle detected by 0, that is, joystick 24
The signal indicating the operation amount θjs and the signal indicating the vehicle speed V detected by the vehicle speed sensor 38 are read, and step 2
At 0, the rotation angle δjs of the steering motor 20 is calculated from the map corresponding to the graph shown in FIG. 4, and step 3
At 0, the control signal corresponding to the rotation angle δjs is output to the steering motor 20 to drive the steering motor, whereby the left and right front wheels are controlled to a turning angle corresponding to the joystick operation amount θjs. It

At step 40, a signal indicating the axial force F acting on the rack bar detected by the axial force sensor 40 is read, and at step 50, a map corresponding to the graph shown in FIG. 5 is read. The reaction torque Tjs is calculated, and in step 60, a control signal corresponding to the reaction torque Tjs is output to the reaction force adding device 32, so that the joystick 24 responds to the reaction torque Tjs via the steering shaft 28. A reaction torque is applied.

Thus, according to the first embodiment, in step 20, the rotation angle δjs of the steering motor 20 is calculated from the map corresponding to the graph shown in FIG. 4, whereby the operation amount θjs of the joystick 24 is calculated. Since the rotation angle δjs is controlled so that the ratio of the actual steering angle of the left and right front wheels to the steering angle is reduced, good steering sensitivity is maintained in the low vehicle speed range, and good maneuverability is ensured during garage entry and lateral approach. At the same time, the sensitivity of steering in the high vehicle speed range can be reduced to prevent over-turning of the steered wheels, and delicate steering can be performed.

Further, as shown in FIG. 4, the maximum pivot angle of the joystick 24 itself is constant regardless of the vehicle speed V (θ
ml, θmr), but since the ratio of the motor rotation angle δjs to the pivot angle θjs decreases as the vehicle speed increases,
As shown in FIG. 6, the maximum actual steering angle φ of the left and right front wheels becomes smaller as the vehicle speed increases. Therefore, even if the mechanical stoppers 36L and 36R are not moved according to the vehicle speed, excessive steering at high speed is reliably prevented. It is also possible to improve the steering stability of the vehicle in the high vehicle speed range.

FIG. 7 is a schematic structural view showing a second embodiment of the steering apparatus according to the present invention, FIG. 8 is a perspective view showing the steering wheel shown in FIG. 7, and FIG. 9 shows the arrangement state of the steering wheel and the like. FIG. In addition, in FIG.
The parts corresponding to the parts shown in are given the same reference numerals as those given in FIG.

In the second embodiment, a steering wheel 42 is provided in addition to the joystick 24 as steering input means. Further, a changeover switch 44 for selecting the joystick 24 or the steering wheel 42 as the effective steering input means operated by the driver is provided. When the switch is in the OFF state, the steering wheel is selected as the effective steering input means. It is supposed to be done. As shown in FIG. 9, the steering wheel 42 is provided at a position in front of the driver's seat as in a normal vehicle, and the joystick 24
Is provided at the position of the center console 45 so that the operation of the steering wheel is not hindered.
The joystick may be provided on the right side or the left side of the steering wheel at a position spaced apart from the steering wheel.

As shown in FIG. 8, a steering angle sensor 48 and a reaction force adding motor 50 are provided on a steering shaft 46 integrally connected to the steering wheel 42. The steering angle sensor 48 detects the operation amount θsw of the steering wheel 42 by detecting the rotation angle of the steering shaft 46, and the reaction force addition motor 50 outputs the steering reaction force torque Tsw in the direction opposite to the rotation direction of the steering wheel 42. It is designed to be applied to the steering shaft 46.

Further, as shown in FIG. 9, the instrument panel 52 has a vehicle speed meter 54 and a tachometer 56.
In addition, the steering wheel lamp 58 and the joystick lamp 60 indicating that the currently effective steering input means are the steering wheel 40 and the joystick 24, respectively, and the changeover switch 44 are operated, but the actual switching of the steering input means is completed. The red lamp 62 indicating that the steering input means has been switched, the green lamp 64 indicating that the steering input means that has been switched but has not been selected is being returned to its neutral position, and the steering input means switching process. There is provided a deviation display lamp 66 which indicates the difference between the operation amount of the selected steering input means and the operation amount of the other still effective steering input means in an analog manner.

Next, the operation of the illustrated second embodiment will be described with reference to the flowcharts shown in FIGS. 10 and 11 and the graphs shown in FIGS. 4, 5, 12, and 13. The control by this flow chart is also started by closing the ignition switch, which is not shown in the figure.
It ends with the opening of the ignition switch. Further, in the flow charts shown in FIGS. 10 and 11, SW and JS mean a steering wheel and a joystick, respectively.

First, in step 100, the steering wheel lamp 58 is turned on, and in step 110, signals indicating the vehicle speed V, the operation amount θsw of the steering wheel 42, and the operation amount θjs of the joystick 24 are read. At 120, it is determined whether or not the changeover switch 44 is in the ON state, and when a positive determination is made, that is, when the driver's intention to select the joystick as an effective steering input means is displayed, step 20 is performed.
0, and when a negative determination is made, step 130
Go to.

At step 130, the red lamp 62 is turned off, and at step 140, the rotation angle δsw of the steering motor 20 is determined from the map corresponding to the graph shown in FIG.
Is calculated, and in step 150, the steering motor is driven by outputting a control signal corresponding to the rotation angle δsw to the steering motor 20, whereby the left and right front wheels become the operation amount θsw of the steering wheel 42. Controlled to the corresponding turning angle. In step 160, the axial force sensor 40
The signal indicating the axial force F acting on the rack bar detected by is read, and the reaction torque Tsw is calculated from the map corresponding to the graph shown in FIG. By outputting the control signal corresponding to Tsw, the reaction force torque corresponding to the reaction force torque Tsw is applied to the steering wheel 42.

In step 170, it is determined whether or not the absolute value of the operation amount θjs of the joystick 24 is less than a small positive constant α, that is, whether or not the joystick is substantially in the neutral position. When a negative determination is made, a control signal is output to the joystick reaction force adding device 32 in step 180, whereby the joystick is driven by a small angle toward its neutral position, and when a positive determination is made. Step 1
At 90, the green lamp 64 is turned off.

At step 200, the red lamp 62 is turned on, at step 210, the reaction force torque Tjs is calculated from the map corresponding to the graph shown in FIG. 5, and the joystick 24 is operated by the reaction force adding device 32. A reaction force torque corresponding to the reaction force torque Tjs is given to. Step 22
At 0, the rotation angles δsw and δjs of the steering motor 20 are calculated from the maps corresponding to the graphs shown in FIGS. 12 and 4, respectively, and at step 230, the control signal corresponding to the rotation angle δsw is given. The steering motor is driven by being output to the steering motor 20, whereby the left and right front wheels are controlled to a turning angle corresponding to the steering wheel operation amount θsw.

In step 240, the reaction torque Tsw is calculated from the map corresponding to the graph shown in FIG. 13, and the steering wheel 4 is driven by the reaction force addition motor 50.
2 is given a reaction torque corresponding to the reaction torque Tsw,
In step 250, the difference δjs−δsw in the motor rotation angle calculated in step 220 is calculated, and the magnitude of the difference is displayed on the deviation display lamp 66, whereby the operation amount θjs of the joystick 24 is calculated. The driver is shown how much and in what direction the joystick should be operated in order to match the operation amount θsw of the steering wheel 42.

In step 260, it is judged whether or not the absolute value of the motor rotation angle difference δjs-δsw is less than a small positive constant ε, that is, the operation amount θjs of the joystick 24 is the operation amount of the steering wheel 42. It is determined whether or not θsw is substantially the same, and if a negative determination is made, the process returns to step 110, and if an affirmative determination is made, the red lamp 62 is turned off and the green color is obtained at step 270. The lamp 64 is turned on, and the steering wheel lamp 58 is turned off and the joystick lamp 60 is turned on in step 280, thereby indicating to the driver that the effective steering input means is switched to the joystick 24, and thereafter. Go to step 290.

In step 290, signals indicating the vehicle speed V, the operation amount θsw of the steering wheel 42, and the operation amount θjs of the joystick 24 are read, and step 30
At 0, it is determined whether or not the changeover switch 44 is in the off state, and when a positive determination is made, that is, when the driver's intention to select the steering wheel as the effective steering input means is displayed, step 380 is performed. If the determination is negative, the process proceeds to step 310.

In step 310, the red lamp 62 is extinguished, in step 320, the rotation angle δjs of the steering motor 20 is calculated from the map corresponding to the graph shown in FIG. 4, and in step 330. First, a control signal corresponding to the rotation angle δjs is output to the steering motor 20 to drive the steering motor, whereby the left and right front wheels are controlled to a turning angle corresponding to the operation amount θjs of the joystick 24. In step 340, the signal indicating the axial force F acting on the rack bar detected by the axial force sensor 40 is read, and the reaction torque Tjs is calculated from the map corresponding to the graph shown in FIG. By outputting the control signal corresponding to the reaction force torque Tjs to the reaction force adding device 32, the reaction force torque corresponding to the reaction force torque Tjs is given to the joystick 24.

In step 350, it is determined whether or not the absolute value of the operation amount θsw of the steering wheel 42 is less than a small positive constant β, that is, whether or not the steering wheel is substantially in the neutral position. When a negative determination is made, a control signal is output to the steering wheel reaction force adding motor 50 in step 360, whereby the steering wheel is driven by a small angle toward the neutral position, and a positive determination is made. If so, the green lamp 64 is turned off in step 370.

At step 380, the red lamp 62 is turned on, and at step 390, the reaction torque Tsw is calculated from the map corresponding to the graph shown in FIG. A reaction force torque corresponding to the reaction force torque Tsw is given to 42. At step 400, the rotation angles δsw and δjs of the steering motor 20 are calculated from the maps corresponding to the graphs shown in FIGS. 12 and 4, respectively, and at step 410, the control signal corresponding to the rotation angle δjs. Is output to the steering motor 20 to drive the steering motor, whereby the left and right front wheels are controlled to a turning angle corresponding to the joystick operation amount θjs.

At step 420, the reaction torque Tjs is calculated from the map corresponding to the graph shown in FIG.
A reaction force torque corresponding to the reaction force torque Tjs is given to the joystick 24 by the reaction force addition device 32, and step 4
At 30, the motor rotation angle difference δsw−δjs calculated at step 400 is calculated, and the magnitude of the difference is displayed on the deviation display lamp 66, whereby the operation amount θjs of the steering wheel 42 is calculated. Joystick 24
The driver is instructed how much the steering wheel should be operated in which direction in order to match the operation amount θsw.

In step 440, it is judged whether or not the absolute value of the motor rotation angle difference δsw-δjs is less than a small positive constant ε, that is, the operation amount θsw of the steering wheel 42.
Is determined to be substantially the same as the operation amount θjs of the joystick 24, and if a negative determination is made, the process returns to step 290, and if an affirmative determination is made, the red lamp 62 at step 450. Is turned off and the green lamp 64 is turned on, and in step 460, the joystick lamp 60 is turned off and the steering wheel lamp 58 is turned on, whereby the effective steering input means is switched to the steering wheel 42. Person, and then returns to step 110.

Thus, according to the second embodiment, the driver operates the changeover switch 44 as required to selectively select either the steering wheel 42 or the joystick 24 as effective steering input means. Therefore, even a driver who is not accustomed to operating the joystick can drive the vehicle without feeling inconvenience or inconvenience of the steering device, and a driver who is accustomed to operating the joystick can The steering input means can be selectively used according to the degree of fatigue and the running condition of the vehicle.

Even if the driver operates the changeover switch 44 and a positive determination is made in step 120 or 300, steps 220 to 260 or steps 400 to 44 are performed.
Since 0 is executed, the actual steering input means is not switched until the operation amount of the selected steering input means substantially coincides with the operation amount of the other steering input means which is still effective. Steering hunting due to switching of the steering input means can be reliably prevented, and thus it is possible to reliably prevent the vehicle from exhibiting an unnatural behavior when the steering input means is switched.

Further, according to this embodiment, since the steering input means which has been effective until then is gradually returned to the neutral position after the switching of the steering input means is completed, the invalid steering input means is suddenly moved to the neutral position. It is possible to reliably prevent the driver from being hindered by being returned, and even if the invalid steering input means is inadvertently operated, the operation is reflected in the actual steering of the steered wheels. Therefore, it is possible to improve the traveling safety of the vehicle as compared with the case of the steering device in which both the joystick and the steering wheel are effective.

The determination in steps 260 and 440 of the second embodiment, that is, whether or not the operation amount θjs of the joystick 24 and the operation amount θsw of the steering wheel 42 are substantially the same is determined. The reference value ε is a positive constant, but when the steering input means is switched, the operation amount θjs
Since the unnatural behavior of the vehicle due to the difference between .theta. And .theta.sw increases as the vehicle speed increases, the reference value .epsilon. Is set to decrease as the vehicle speed V increases. Driving safety may be further improved.

14 and 15 are schematic configuration diagrams showing the third and fourth embodiments of the steering apparatus according to the present invention, respectively. In these figures, the parts corresponding to the parts shown in FIG. 1 have the same signs as the signs given in FIG. 1 and the signs having left and right signs L and R. It is attached.

In the third embodiment shown in FIG. 14,
A backrest 72 of the driver's seat 70 is pivotally supported by a pair of left and right armrests 74L and 74R, and a pair of left and right joysticks 24L and 24R are provided at the front ends of these armrests. Further, in the fourth embodiment shown in FIG. 15, a joystick support member 78 having a substantially T shape is fixed to the dashboard 76 below the instrument panel 52, and the support member 78 is A pair of left and right joysticks 24L and 24R are provided at the tip of the arm portion extending in the left-right direction.

Further, in the third embodiment, as shown in FIGS. 16 and 17, the joysticks 24L and 24R are pivotally supported by a ball joint type, and the push-pull cable 80 for steering and the acceleration / deceleration are used. Push-pull cable 82 is wound around a plurality of pulleys 84 and 86, respectively, which are armrests 74L and 74R.
And in the backrest 72. The push-pull cables 80 and 82 extend in a double U-shape with a front opening, and are attached to the tips of the stopper arms 34L and 34R of the joysticks 24L and 24R at the portions of the front end of the push-pull cable 80 that extend in the left-right direction. And a portion extending in the front-rear direction inside the push-pull cable 82 is connected to the tips of the stopper arms 34L and 34R.
As a result, the joysticks 24L and 24L are interlocked with each other with respect to pivoting in the left-right direction and the front-rear direction.

The push-pull cable 80 includes an operation amount detection sensor 86 such as a sliderac for detecting the lateral operation amount θjs of the joysticks 24L and 24R by detecting the reciprocating distance thereof. A reaction force adding device 88 for applying a reaction force in the direction opposite to the reciprocating direction by an electromagnetic force or a spring force and an electromagnetic force is provided. Similarly, the push-pull cable 82 has an operation amount detection sensor 90 that detects the pivoting operation amount Ajs in the front-rear direction of the pair of joysticks by detecting the reciprocating distance thereof, and the push-pull cable 82 has a reciprocating direction. Reaction force adding device 92 for applying a reaction force in the opposite direction
Are provided.

Although not shown in the figure, a signal indicating the lateral operation amount θjs of the joystick 24L or 24R detected by the operation amount detection sensor 86 is output to a steering electronic control unit similar to the electronic control unit 26. As a result, the left and right front wheels are steered according to the operation amount θjs. Further, a signal indicating the operation amount Ajs detected by the operation amount detection sensor 90 is output to the engine control device, whereby the output of the engine is increased or decreased according to the operation amount Ajs to accelerate or decelerate the vehicle. .

Although not shown in the drawing, in the fourth embodiment, the push-pull cables 80 and 82 have a substantially rectangular shape in the arm portion extending in the left-right direction of the joystick support member 78. Except that it is arranged
The configuration is similar to that of the third embodiment, whereby the pair of left and right joysticks 24L and 24R interlock with each other.

According to these third and fourth embodiments, the driver's seat is provided with a pair of left and right joysticks 24L and 24R, and the two joysticks interlock with each other. If necessary, you can operate the corresponding joystick with both hands, you can easily change the left and right hands when driving with one hand, and you can always use your skillful hand when driving with one hand.

The interlocking of the joysticks 24L and 24R in the above embodiment is achieved by the push-pull cables 80 and 82, but may be achieved by a link mechanism or a gear train. Also, three or more joysticks may be provided.

18 and 19 are flow charts showing a part and the rest of the control flow of the fifth embodiment of the steering apparatus according to the present invention which is constructed as a modification of the second embodiment described above. . 18 and 19, steps corresponding to the steps shown in FIGS. 10 and 11 are given the same step numbers as those shown in FIGS. 10 and 11. Although not shown in the figure, the configuration of the steering system of this embodiment is shown in FIG.
Except that the deviation indicator lamp 66 shown in FIG.
The configuration is the same as that of the second embodiment.

In step 220 of this embodiment, the rotation angle δjs is not calculated, but only the rotation angle δsw of the steering motor 20 is calculated from the map corresponding to the graph shown in FIG. Further, in step 255, it is judged whether or not the absolute value of the operation amount θsw of the steering wheel 42 is less than the reference value θs1 (a minute positive constant), that is, whether or not the steering wheel is substantially in the neutral position. If a positive determination is made, step 255
In this case, for example, the steering speed θswd of the steering wheel is calculated by differentiating the operation amount θsw of the steering wheel 42, and whether the absolute value of the steering speed θswd is less than the reference value θs2 (a minute positive constant). It is determined whether or not the steering wheel 42 is substantially not operated, and when the determination is affirmative, the process proceeds to step 270. If a negative determination is made in step 255 or 265, step 11
Return to 0.

Similarly, in step 400 of this embodiment, the rotation angle δsw is not calculated, but only the rotation angle δjs of the steering motor 20 is calculated from the map corresponding to the graph shown in FIG. Further, in step 435, it is judged whether or not the absolute value of the operation amount θjs of the joystick 24 is less than the reference value θj1 (a minute positive constant), that is, whether or not the joystick is substantially in the neutral position. When the determination is made and the affirmative determination is made, in step 445, for example, the operation amount θjs of the joystick 24 is differentiated to calculate the steering speed θjsd of the joystick and the absolute value of the steering speed θjsd is set to the reference value. θj2
It is determined whether or not it is less than (a minute positive constant), that is, whether or not the joystick 24 is substantially operated, and when a positive determination is made, step 4
Go to 50. If a negative determination is made in step 435 or 445, the process returns to step 290.

Thus, according to the fifth embodiment, similarly to the second embodiment, the driver can change the switch 44 as necessary.
By operating, the steering wheel 42 and the joystick 24 can be selectively selected as effective steering input means. Therefore, even a driver who is not accustomed to operating the joystick may have poor operability of the steering device. It is possible to drive the vehicle without feeling any disadvantage, and a driver who is accustomed to operating the joystick can freely use the steering input means according to his / her fatigue level or the traveling condition of the vehicle.

According to the fifth embodiment, after the driver operates the changeover switch 44, the steering input means, which is still effective, is positioned substantially in the neutral position and the vehicle is in a straight traveling state. Since the steering input means is automatically switched, it is not necessary to match the operation amount of the selected steering input means with the operation amount of the steering input means which is still effective as in the second embodiment. As compared with the case of the second embodiment, it is possible to easily switch the steering input means during traveling of the vehicle.

For steering input means not selected, steps 170 to 190 or steps 350 to 370.
Is executed, the unselected steering input means is controlled to the substantially neutral position, and the driver operates the changeover switch 44 to perform step 120 or 30.
Even if an affirmative determination is made in step 0, steps 220 to 26 are executed.
5 or steps 400 to 445 are executed, the actual steering input means is not switched until the steering input means which is still valid is substantially positioned at the neutral position. Therefore, the steering input means is switched. Steering hunting caused by the steering can be surely prevented, so that the vehicle can be surely prevented from exhibiting an unnatural behavior when the steering input means is switched, and the steering wheel 42 and the joystick 24 are switched by the steering input means being switched.
It is possible to prevent the neutral position of the vehicle from being displaced.

The steering wheel 42 is discriminated in step 265 in addition to the discrimination in step 255, and the joystick 24 is discriminated in step 43.
By executing the determination of step 445 in addition to the determination of 5, the steering input means can be switched not only when the steering wheel and the joystick are in the neutral position but also when the steering speed thereof is substantially zero. Therefore, compared to the case where the steering input means is switched if the steering wheel or joystick is in the neutral position, the steering wheel and joystick may be displaced from each other by the switching of the steering input means. It can be further reduced.

Further, in the fifth embodiment as well, after the completion of the switching of the steering input means, the steering input means which has been effective until then is gradually returned to the neutral position, so that the invalid steering input means is suddenly changed. It is possible to reliably prevent the driver from being hindered by being returned to the neutral position, and even if the ineffective steering input means is inadvertently operated, the operation is Since it is not reflected in the steering, the driving safety of the vehicle can be improved as compared with the case of the steering device in which both the joystick and the steering wheel are effective.

Also in this fifth embodiment, step 2
The reference values .theta.s1 and .theta.s2 used in the determinations 55 and 265, that is, the determination whether the steering wheel 42 is substantially in the straight traveling position of the vehicle, are small positive constants, and in steps 435 and 445. The reference values θj1 and θj2 for the determination, that is, whether the joystick 24 is substantially in the straight traveling position of the vehicle are positive constants, but the operation amounts θjs and θsw are different when the steering input means is switched. Since the unnatural behavior of the vehicle due to the vehicle speed increases as the vehicle speed increases, these reference values are set to decrease as the vehicle speed V increases, thereby ensuring the safety of the vehicle when the steering input means is switched. May be further improved.

Although the present invention has been described above in detail with reference to specific embodiments, the present invention is not limited to these embodiments, and various other embodiments within the scope of the present invention. It will be apparent to those skilled in the art that

For example, in each of the above-mentioned embodiments, the accelerator operation can be performed in addition to the steering operation by operating the joystick. For example, the joystick can be operated by providing the joystick with a braking lever or a braking knob. Alternatively, the joystick may be configured to be pivotable only in the left-right direction of the vehicle so that only the steering operation can be performed. In particular, in the second to fifth embodiments, if the joystick is configured to be able to perform braking by its operation, even if the driver is incapable of driving for some reason, another occupant will be in the auxiliary seat side. Alternatively, by operating the joystick from the rear seat side, it is possible to reliably take evacuation action in an emergency.

In the second and fifth embodiments described above, the steering wheel 42 is automatically selected as an effective steering input means at the start of traveling of the vehicle. The automatically selected steering input means may be the joystick 24, or the steering input means automatically selected at the start of traveling of the vehicle may be selected by a switch operated by the driver. Good.

[0064]

As is apparent from the above description, according to the structure of claim 1, the higher the vehicle speed, the smaller the ratio of the actual steering angle of the steered wheels to the operation amount of the joystick, so that in the low vehicle speed range. The steering sensitivity in the high vehicle speed range can be reduced while maintaining good steering sensitivity to prevent over-wheeling of the steered wheels and delicate steering can be performed. It is possible to improve operability and steering stability of the vehicle when traveling at high speed.

Although the maximum pivot angle of the joystick itself is constant regardless of the vehicle speed, the ratio of the actual steering angle of the steered wheels to the operation amount of the joystick becomes smaller as the vehicle speed becomes higher, and the maximum actual steering angle of the steered wheels becomes Since it decreases as the vehicle speed increases, it is possible to reliably prevent excessive steering at high speeds without changing the pivotable angular range of the joystick according to the vehicle speed. The steering stability of the vehicle can be improved.

According to the second and fourth aspects, the driver can selectively select either the joystick or the steering wheel as effective steering input means by operating the changeover switch. It is possible to reliably avoid a driver who is not accustomed to operating the joystick from feeling inconvenience or inconvenience.

According to the second aspect of the present invention, in actual switching of the steering input means, the operation amount of the steering input means selected by the changeover switch becomes a value substantially corresponding to the actual steering angle of the steered wheels. Since it is executed at the time, the hunting when the steering input means is switched can be reliably prevented, and the steering input means can be switched smoothly. As a result, the maneuverability is deteriorated due to the switching of the steering input means. Can be reliably prevented.

Further, the actual switching of the steering input means is executed when the operation amount of the selected steering input means substantially reaches a value corresponding to the actual steering angle of the steered wheels. The steering input means can be optionally switched as compared with the case of the structure in which the actual switching is performed only when the vehicle is substantially traveling straight ahead.

According to the third aspect of the invention, since a plurality of joysticks are provided and the joysticks are configured to interlock with each other, the driver can operate the corresponding joysticks with both hands as necessary. You can change your left and right hands, and you can always use your right-handed arm regardless of right-handed or left-handed, which improves the operability of the steering device compared to the past and reduces fatigue caused by steering by the driver. However, it is possible to reliably prevent deterioration of maneuverability associated with holding the left and right hands.

Further, according to the structure of claim 4, the steering input means not selected by the changeover switch is substantially positioned at the neutral position, and the actual changeover of the steering input means is still present after the changeover switch is operated. Since it is executed when the effective operation amount of the steering input means becomes substantially zero, hunting when the steering input means is switched can be reliably prevented, and the steering input means can be switched smoothly. For example, as in the case of the structure of claim 2, it is necessary to compare the operation amount of the steering input means selected by the changeover switch with a value corresponding to the actual steering angle of the steered wheels, that is, the operation amount of the steering input means which is still effective at present. Therefore, the switching control of the steering input means can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a steering device according to the present invention.

FIG. 2 is a perspective view showing the joystick shown in FIG.

FIG. 3 is a flowchart showing a control flow of the first embodiment.

FIG. 4 is a graph showing an example of the relationship between the operation amount θjs of the joystick and the corresponding rotation angle δjs of the steering motor.

FIG. 5 is a graph showing an example of a relationship between an axial force F and a steering reaction force torque Tjs with respect to a joystick.

FIG. 6 is a graph showing the relationship between the vehicle speed V and the absolute value of the maximum actual steering angle φ of the left and right front wheels.

FIG. 7 is a schematic configuration diagram showing a second embodiment of the steering device according to the present invention.

8 is a perspective view showing the steering wheel shown in FIG. 1. FIG.

FIG. 9 is an explanatory diagram showing an arrangement state of a steering wheel and the like.

FIG. 10 is a flowchart showing a part of a control flow of the second embodiment.

FIG. 11 is a flowchart showing the remaining part of the control flow of the second embodiment.

FIG. 12 is a graph showing an example of the relationship between the steering wheel operation amount θsw and the corresponding rotation angle δsw of the steering motor.

FIG. 13 is a graph showing an example of a relationship between an axial force F and a steering reaction force torque Tsw with respect to a steering wheel.

FIG. 14 is a schematic configuration diagram showing a third embodiment of the steering device according to the present invention.

FIG. 15 is a schematic configuration diagram showing a fourth embodiment of the steering device according to the present invention.

FIG. 16 is a schematic configuration diagram showing an interlocking mechanism for steering operations of the left and right joysticks in the third and fourth embodiments.

FIG. 17 is a schematic configuration diagram showing an interlocking mechanism for acceleration / deceleration operations of the left and right joysticks in the third and fourth embodiments.

FIG. 18 is a flowchart showing a part of a control flow of a fifth embodiment of the steering system according to the present invention.

FIG. 19 is a flowchart showing the remaining part of the control flow of the fifth embodiment.

[Explanation of symbols]

 10 ... Rack and pinion type steering device 20 ... Steering motors 24, 24L, 24R ... Joystick 26 ... Electronic control device 30 ... Steering angle sensor 32 ... Reaction force adding device 38 ... Vehicle speed sensor 42 ... Steering wheel 44 ... Changeover switch 48 ... Steering angle sensor 50 ... Reaction force addition motor 86, 90 ... Operation amount detection sensor 88, 92 ... Reaction force addition device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B62D 121: 00

Claims (4)

[Claims] 1. A joystick capable of pivoting over a predetermined angle range, an operation amount detection means for detecting an operation amount of the joystick, and a steering mechanism for steering a steered wheel in accordance with the operation amount of the joystick. The vehicle steering system has a vehicle speed detection means and a control means for controlling the steering mechanism such that the higher the vehicle speed, the smaller the ratio of the actual steering angle of the steered wheels to the operation amount of the joystick. A vehicle steering system characterized by the above. 2. A vehicle having a joystick and a steering wheel, an operation amount detecting means for detecting an operation amount of the joystick and the steering wheel, and a steering mechanism for steering a steered wheel according to an operation amount of the joystick or the steering wheel. In the steering system,
A changeover switch for selecting a joystick or a steering wheel as effective steering input means, and when the operation amount of the steering input means selected by the changeover switch becomes a value substantially corresponding to the actual steering angle of the steered wheels, A steering apparatus for a vehicle, comprising: a switching control means for executing an actual switching of the steering input means. 3. A joystick capable of pivoting over a predetermined angle range, an operation amount detecting means for detecting an operation amount of the joystick, and a steering mechanism for steering a steered wheel in accordance with the operation amount of the joystick. In a vehicle steering system, a plurality of joysticks are provided, and each joystick is configured to interlock with each other. 4. A vehicle having a joystick and a steering wheel, an operation amount detecting means for detecting an operation amount of the joystick and the steering wheel, and a steering mechanism for steering a steered wheel according to an operation amount of the joystick or the steering wheel. In the steering system,
A changeover switch for selecting a joystick or a steering wheel as an effective steering input means, a means for substantially positioning the steering input means not selected by the changeover switch to a neutral position, and the present switch after the changeover switch is operated. A vehicle steering system comprising: a switching control means for executing an actual switching of the steering input means when an effective operation amount of the steering input means becomes substantially zero.