JP2998864B2 - Automatic vehicle steering control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for automatically performing a steering operation of a vehicle, and more particularly to a control for starting and canceling automatic steering.

[0002]

2. Description of the Related Art There has been proposed a technology relating to an automatic steering device for automatically performing a steering operation of a vehicle without a driver operating a steering wheel. For example, a hydraulic or electric drive system for automatic steering is connected to the steering mechanism, an image in an area equivalent to the driver's field of view is input using a television camera or the like, and the input image is processed to perform lane markings, signs, etc. If the road information of the vehicle or the like is detected, the steering amount can be adjusted so that the vehicle travels in a predetermined lane based on the information, or the traveling lane can be changed so as to avoid an obstacle by automatic steering. .

By the way, if an automatic steering is to be performed automatically by directly coupling a hydraulic mechanism or an electric mechanism to a normal steering mechanism, the steering wheel (automatic steering) can be operated according to the steering amount without any operation by the driver. Steering wheel)
Will rotate on its own. Such a phenomenon is not preferable depending on the situation, and it is preferable that the steering wheel does not rotate even during automatic steering unless the driver operates the steering wheel.

In a general steering mechanism, a pinion is provided at a tip of a steering shaft which rotates in accordance with rotation of a steering wheel, and a rack having teeth formed to engage with the pinion linearly moves in the left-right direction. The tie rods, which are steering shafts, are respectively connected to both ends of the rack, and each tie rod is connected to the turning axis of each of the left and right tires.

Accordingly, the applicant has provided a drive shaft having a shape similar to that of a rack, inserting the drive shaft between the rack and each tie rod, and adjusting the relative position between the rack and the drive shaft. There has already been proposed a steering mechanism in which the steering mechanism is configured to be able to perform automatic steering by the drive mechanism and to enable automatic steering by moving a tie rod in a state where the steering wheel does not move. Even in such a configuration, when the reaction force from the road surface during steering is large, the reaction force is transmitted to the steering shaft via the countershaft and the rack, and the steering wheel may rotate. Because there is
It has also been proposed to restrain the movement of the steering wheel during automatic steering by using an electromagnetic clutch or the like (Japanese Patent Application No. Hei.
-229926).

[0006]

By the way, even in a vehicle which can perform automatic steering on an exclusive road (highway) where driving is easy, for example, manual steering must be performed on a general road. In the device for restraining the movement of the steering wheel, when performing manual steering, in order to reduce the movement of the steering wheel,
It is desirable to release the constraint. However, when the restraining force of the steering wheel is released at once, the steering feeling (weight of the steering wheel) felt by the driver suddenly becomes lighter, so that the driver feels uneasy or uses the steering wheel. There is a possibility that the driving operation is erroneously performed due to excessive turning. However, if the restraint is not released, a large force is required to turn the steering wheel, so that it is difficult for a woman with a weak force, for example, to drive such a car.

Accordingly, the present invention releases the restraint of the steering wheel during automatic steering to facilitate driving, and provides a driver with an uncomfortable feeling or an erroneous driving operation by releasing the restraint. And to improve the safety of automatic steering.

[0008]

According to the present invention, there is provided, in accordance with the present invention, a steering input device operated by a driver to instruct a change in the traveling direction of a vehicle, and an operation of the steering input device combined with the steering input device. A first steering member that generates displacement according to the amount, a second steering member that is coupled to a support shaft of each wheel and changes the direction of each wheel with respect to the vehicle by moving the first steering member, the first steering member and the second A vehicle comprising: automatic driving means for automatically adjusting a relative positional relationship with a steering member; and restraining means for engaging at least one of the steering input means and the first steering member to restrain the movement thereof. In the automatic steering control device, a restraining force varying means for changing a restraining force of the restraining means; and when a predetermined automatic steering release condition is satisfied in the automatic steering mode, the restraining is performed. It provided; by controlling the variable means the gradual restraining force control means for reducing the restraining force over time restraint.

According to a second aspect of the present invention, there is provided a main steering angle detecting means for detecting a steering amount of the steering input means or the first steering member. Is automatically released when the main steering angle detecting means detects the steering angle. In the third invention, the magnitude of the torque applied to the steering input means or the first steering member is adjusted. The main steering torque detecting means for detecting the steering force is provided, and the restraining force control means is configured to automatically release the automatic steering when the main steering torque detecting means detects a main steering torque equal to or more than a predetermined value. According to the present invention, an acceleration detecting means for detecting the longitudinal acceleration of the vehicle is provided, and the restraining force control means is automatically operated when the acceleration detecting means detects a predetermined or more longitudinal acceleration. In the fifth aspect of the present invention, there is provided a brake detecting means for detecting the presence or absence of a braking operation on the vehicle, and the restraining force control means is provided for automatically steering when the braking operation is detected. In the sixth aspect of the present invention, a sensor abnormality detecting means for detecting the presence or absence of a failure of a sensor for detecting information necessary for automatic steering is provided, and the restraining force control means is provided at least. When a failure of one sensor is detected, the automatic steering is automatically released.

[0010]

According to the present invention, the magnitude of the restraining force of the restraining means can be adjusted by controlling the restraining force variable means. When a predetermined automatic steering release condition is satisfied in the automatic steering mode, the restraining force control means controls the restraining force variable means to gradually reduce the restraining force of the restraining means over time. Therefore, when the automatic steering is released, the weight of the steering wheel felt by the driver gradually decreases over time. For this reason, the possibility of the driver feeling uneasy due to a change in the operational feeling due to the release of the restraint of the steering wheel or the possibility of erroneous driving operation due to excessive turning of the steering wheel is extremely reduced, and safety is improved.

When emergency manual steering is required during the automatic steering operation, the driver manually turns the steering wheel or depresses the brake pedal. Further, when an abnormality occurs in various sensors used for automatic steering, it is necessary to switch to manual steering. So the second
In the third invention, the automatic steering is released when the main steering angle detecting means detects a main steering amount larger than a predetermined value, and in the third invention, the automatic steering is released when the main steering torque detecting means detects the main steering torque larger than a predetermined value. According to a fourth aspect of the present invention, the automatic steering is released when the acceleration detecting means detects a longitudinal acceleration equal to or more than a predetermined value. In a fifth aspect, the automatic steering is performed when a braking operation such as depression of a brake pedal is detected. In the sixth aspect of the invention, when a failure of the sensor is detected, the automatic steering is released, and in any case, the restraint of the steering wheel is released.

[0012]

1 and 5 show a main part of a steering mechanism of an automobile. Note that, although a part is simplified or omitted in FIG. 1, the details of the right end portion in FIG. 1 are shown in FIG. 2, and the details of the left end portion are shown in FIG. FIG. 5 shows a portion arranged inside the steering column. The upper end of the main shaft 51 is connected to a steering wheel (not shown), and the lower end of the main shaft 51 is connected to an intermediate shaft for connection (not shown). 1 is coupled to the input shaft 91 shown in FIG. When the driver turns the steering wheel, the main shaft 51 is rotated.
Rotate, and the rotational power is transmitted to the input shaft 91 in FIG. Although the steering mechanism shown in FIG. 1 is provided with a power steering mechanism, the basic configuration and operation of the mechanism are well known in the related art, and a description thereof will be omitted here.

The steering mechanism shown in FIG. 1 is basically of a rack and pinion type, and has an input shaft 9.
1 is provided with a pinion 92 at the tip thereof.
Are formed on the outer periphery of the. A shaft-shaped rack 84 is arranged so that the shaft crosses the pinion 92. Teeth are formed on a part of the outer peripheral surface of the rack 84 that faces the pinion 92, and the teeth always mesh the rack 84 and the pinion 92 to connect them.

In this embodiment, the rack 84 is formed in a hollow, that is, in a cylindrical shape, and has a lateral power inside.
A shaft 82 is provided. The lateral power shaft 82 is slidably supported on the rack 84 in the axial direction, that is, in the left-right direction. Lateral power shaft 8
A tie rod 122R is connected to the right end of the tie rod 122 via a ball joint 120R.
The direction of the right front wheel changes as R moves in the left-right direction. Similarly, on the left end of the lateral power shaft 82,
Tie rod 122L via ball joint 120L
The direction of the left front wheel changes when the tie rod 122L moves left and right. The lateral power shaft 82 and the rack 84 can move relative to each other in the axial direction, but a hydraulic actuator 130 is connected between the two, and the hydraulic actuator 130 regulates the relative movement between the two. Active steering enables automatic steering. That is, as shown in FIG. 3, a piston 134 formed on the lateral power shaft 82 is disposed in the inner space of the cylinder 132 fixed to the left end side of the rack 84. Ports 138 and 140 communicating with each of the inner spaces 133 of the cylinder 132 separated by the piston 134 are connected to a hydraulic circuit described later. If the cylinder 132 is filled with oil to block the inflow and outflow of oil from the ports 138 and 140, the movement of the piston 134 in the cylinder 132 is restricted, so that the relative movement between the lateral power shaft 82 and the rack 84 Movement is substantially eliminated, and the movement of the rack 84 is transmitted to the lateral power shaft 82 as it is. Therefore, when the steering wheel is operated in the same manner as a general steering device, the pinion is transmitted via the main shaft 51 and the intermediate shaft. 92 rotates, and the rack 84 moves in the left and right direction, and the movement is transmitted to the lateral power shaft 82 via the hydraulic actuator 130 to steer the wheels.

Even when the steering wheel is not operated, the cylinder 132 is operated by operating the hydraulic circuit.
By moving the position of the piston 134 within, the lateral power shaft 82 moves relative to the rack 84 and the direction of the wheels changes. In other words, by driving the hydraulic actuator 130, it is possible to perform compensatory assist steering for the operation of the steering wheel, or to perform completely automatic steering.

By the way, when performing complete automatic steering, the driver releases his / her hand from the steering wheel. Therefore, when the reaction force from the road surface to the steering force is large, the force is applied to the lateral power shaft. 82, hydraulic actuator 130, rack 84, main shaft 51
And the like, the steering wheel is rotated by itself, and as a result, the steering amount becomes smaller than the target value. In order to eliminate such inconvenience, in this embodiment, a mechanism for restraining the movement of the steering wheel in the case of automatic steering is provided.

The restraining mechanism will be described with reference to FIG. The plate-shaped stay 56 is fixed to a fixed member 62 of the steering column by a screw 63, and rotatably supports the main shaft 51 via a bearing 57. The rotor 53 formed in a disk shape has a spacer 5
5 keeps a predetermined distance from the stay 56, and is fixed to the main shaft 51 by a key 52. An annular movable plate 58 is arranged on the outer periphery of the small diameter portion of the rotor 53, and the movable plate 58 is connected to the rotor 53 via a leaf spring 60. The leaf spring 60 includes the rotor 5
3 and the movable plate 58 are fixed to each of the rivets by caulking. The frame 6 fixed to the lower surface of the stay 56
An electric coil 61 is mounted inside the frame 4, and a friction material 59 formed in an annular shape is mounted on a surface of the frame 64 facing the movable plate 58. 54 is an electric coil 61
It is a lead wire drawn from the above.

When the electric coil 61 is not energized, the movable plate 58 is brought closer to the large diameter portion (lower side) of the rotor 53 by the force of the leaf spring 60, and the movable plate 58 and the friction material 59 are separated. . Therefore, in that state, the main shaft 51 can move freely. When the electric coil 61 is energized, the movable plate 58 made of a magnetic material receives a force attracted to the electric coil 61, moves upward, abuts against the surface of the friction material 59, and is held in that state. Therefore, in that state, the frictional force between the fixed friction material 59 and the movable plate 58 causes
The movement of the movable plate 58 in the turning direction is restricted. Therefore, the rotation of the rotor 53 and the main shaft 51 is also restricted.
However, since this binding force is due to frictional force, the force is not so large, and the movement of the main shaft 51 can be reliably stopped against a reaction force from the road surface, but with a relatively large force in an emergency or the like. When the steering wheel is operated, even when the electric coil 61 is energized, the movable plate 58 can move relative to the friction material 59 and steering by the driver is possible.

A mechanism is provided near the right end of the lateral power shaft 82 for automatically returning the relative position between the lateral power shaft 82 and the rack 84 to the neutral position in the event of a failure of the hydraulic actuator 130 or the like. Have been. That is, as shown in FIG. 2, a compression coil spring 175 and a cylindrical stopper 173 having a flange formed in contact with both ends of the compression coil spring 175 inside the housing members 171 and 172 fixed to the right end of the rack 82.
And 174 are provided. Stoppers 173 and 17
4 is slidable on a lateral power shaft 82,
From the neutral position, the lateral power shaft 82
When moving in the direction of arrow AR with respect to
The movement of 74 is regulated by the housing member 172,
The stopper 173 is pushed by the lateral power shaft 82 and moves in the direction of the arrow AR together therewith.
Compress 5 Therefore, the spring 175 is connected to the stopper 1
73 is pressed in the direction of arrow AL, and the lateral power shaft 82 engaged with the stopper 173 receives a force to return to the neutral position. Conversely, when the lateral power shaft 82 moves in the direction of the arrow AL with respect to the rack 84 from the neutral position, the movement of the stopper 173 is restricted by the housing member 171, and the stopper 174 is pushed by the lateral power shaft 82 and the arrow AL is moved therewith. Move in the direction
The spring 175 is compressed. Therefore, the spring 175
Presses the stopper 174 in the AR direction,
Lateral power shaft 82 engaging with 4 is forced to return to the neutral position.

The auxiliary steering angle sensor 150 is mounted outside the housing member 171. The sensor 150 is a potentiometer having a slider that slides in the axial direction, and the slider is engaged with an arm 176 fixed to the ball joint 120R. When the lateral power shaft 82 moves with respect to the rack 84, the arm 176 moves in the axial direction with respect to the housing member 171, and
The slider of the auxiliary steering angle sensor 150 moves. Accordingly, the auxiliary steering angle sensor 150 detects the lateral power with respect to the rack 84.
The relative position of the shaft 82 is detected.

Reference numerals 180 shown in FIG. 2 and 191 and 192 shown in FIG. 3 are boots for preventing dust from entering the mechanism. Although the boots 191 and 192 shown in FIG. 3 have a general structure, the boot 180 shown in FIG.
Has a special twist. That is, a general boot is composed of one part formed by blow molding. As shown in FIG. 3, the center position of each opening formed at both ends coincides with the center axis of the boot. Limited to positions where However, as shown in FIG. 2, in this example, the auxiliary steering angle sensor 150 is arranged so as to protrude above the housing member 171.
Since the boot inclusion is not arranged symmetrically with respect to the center axis of the boot, the opening formed at the position of the tie rod 122R covers the entire part with the boot arranged on the center axis. Requires large boots and wasteful space. Further, if the boot is constituted by one component, the openings at both ends are small, so that the assembly and removal must be performed in a predetermined order, and the boot is mounted after the mechanical components are assembled. Can not do. It is desirable that the boot can be mounted after the mechanical parts are assembled.

Therefore, in this embodiment, as shown in FIGS. 2 and 4, a boot is constructed by combining a plurality of parts, and the opening of the boot is formed at a position shifted from the center axis. is there. Referring to FIG. 4, the boot comprises a bellows-shaped boot main body 181, side covers -182 and 183 mounted on both ends thereof, and ring-shaped brackets 184 and 185. Both ends of the boot main body 181 have relatively large openings, and side covers -182 and 183 are mounted so as to cover these openings.
Side covers -182 and 183 have relatively small openings 182a corresponding to the shape of the mechanism for mounting the boots.
And 183a, respectively, and these openings 182a and 183a are formed at positions offset from the center axis of the boot.

When assembling the boot 180 on a steering mechanism as shown in FIG.
3 only on the steering gear housing 90,
Next, the stoppers 173 and 174, the compression coil spring 175, the housing members 171 and 172, the auxiliary steering angle sensor 150 and the like are assembled, and the boot body 181 is mounted so as to cover them, and the side cover is attached to the boot body 181. 18
Fit 3 Since the opening of the boot main body 181 is large, other mechanical parts do not interfere with the boot when the boot is mounted, and the assembling is easy.

FIG. 8 shows the configuration of an electric circuit and a hydraulic circuit for controlling the above-described steering mechanism. First, the hydraulic circuit will be described with reference to FIG. 11 is a pump, 12 is an accumulator, 13 is a three-position switching solenoid valve, and 14 is a reservoir. When the three-position switching solenoid valve 13 is set to the first state, the high-pressure oil from the pump 11 is supplied to the right chamber of the cylinder 132 and the oil in the left chamber of the cylinder 132 flows to the reservoir 14 at the same time. The piston 134 moves to the left. Similarly, when the three-position switching solenoid valve 13 is set to the second state, high-pressure oil from the pump 11
32, and at the same time, oil in the right chamber of the cylinder 132 flows to the reservoir 14, so that the piston 1
34 moves to the right. When the three-position switching solenoid valve 13 is set to the third state, the inflow and outflow of oil from each port of the cylinder 132 is shut off, and the amount of oil in each chamber does not change, so that the position of the piston 134 is fixed. . Piston 13
The relative positional relationship between the rack 84 and the lateral power shaft 82 according to the position of No. 4 is detected by the auxiliary steering angle sensor 150.

Next, the electric circuit will be described. This embodiment is provided with an automatic steering mode capable of automatically traveling in a predetermined traveling lane (lane) without operating a steering wheel on a highway or the like. In this automatic steering mode, the television camera 21 repeatedly inputs an image in front of the vehicle which substantially corresponds to the driver's field of view. The input image is processed by the image processing & lane detection unit 22, and the current positional relationship between the vehicle and the lane and the direction of the lane ahead are detected as information necessary for steering. This is done by, for example, using a laser radar to sense several markers in front of the vehicle embedded on the road in advance and calculating the distance and azimuth between the own vehicle and the sensed markers. , Road conditions ahead (straight or curved)
May be detected. The electronic control unit ECU
The direction to be steered and the steering amount are determined based on the information output from the image processing & lane detection unit 22 and the information output from various other sensors, and the linear pressure control of the hydraulic circuit is performed according to the steering amount. Valve 15 and 3-position switching solenoid valve 13
And automatically control the steering system. In addition, automatic steering mode
In the mode, the electromagnetic clutch 25 (restriction mechanism in FIG. 5) is controlled to restrict the rotation of the steering wheel. The electromagnetic clutch 25 is controlled via the driver 24.

In this embodiment, the auxiliary steering angle sensor 1 is used as a sensor for detecting information necessary for controlling automatic steering.
50, main steering angle sensor 160, vehicle speed sensor 71, front and rear G
A sensor 72, a steering torque sensor 73, and a yaw sensor 74 are provided. Further, in order to enhance the reliability of the system, an abnormality detection circuit 75 for detecting whether or not each of the above sensors is functioning normally is provided. SW is a changeover switch for turning on / off the automatic steering mode, and BK is a brake switch for turning on / off according to whether or not the brake pedal is depressed.

The main steering angle sensor 160 detects the steering angle of the steering input shaft which changes according to the operation of the steering wheel by the driver. In this embodiment, as shown in FIG. Installed in part. Specifically, the main steering angle sensor 160 is a potentiometer and detects the rotation angle of the pinion 92. The front-rear G sensor 72 detects the magnitude of the acceleration applied in the front-rear direction of the vehicle body. The steering torque sensor 73 is
The magnitude of the torque applied to the steering input shaft, which is changed by the operation of the steering wheel by the driver, is detected. The yaw rate sensor 74 is disposed near the position of the center of gravity of the vehicle body, and detects an angular velocity in a rotational direction about a vertical axis passing therethrough, that is, a yaw angular velocity.

In this embodiment, the driver 24 for controlling the energization of the electromagnetic clutch 25 is configured as shown in FIG. This will be described with reference to FIG. The target value is output from the electromagnetic control unit ECU as a voltage. The voltage-duty converter 31 generates a pulse signal having a constant cycle, and changes the on / off duty of the pulse signal according to the magnitude of the input signal voltage. Voltage-duty converter 3
The output of 1 is applied to the electric coil 61 of the electromagnetic clutch through the current amplifier 32. Therefore, the average value of the current flowing through the electric coil 61 changes in proportion to the duty of the pulse output from the voltage-duty converter 31. A voltage proportional to the current value of the electric coil 61 appears between the terminals of the resistor R connected in series with the electric coil 61. This voltage is amplified by the amplifier 33, smoothed by the smoothing circuit 34, and fed back to the input of the voltage-duty converter 31.

Therefore, when the average value of the current flowing through the electric coil 61 is smaller than the target value, the pulse duty is updated in a direction of increasing the current, the energizing current increases, and the average value of the current flowing through the electric coil 61 becomes the target value. When it is larger, the pulse duty is updated in a direction to decrease, and the energizing current is reduced, and the energizing current is constantly controlled so as to approach the target value. Therefore, even if the electric coil 61 generates heat and its resistance value changes, the restraining torque does not change. As will be described later, in this embodiment, when releasing the restriction, the ECU changes the target value so as to gradually reduce the restriction torque.

FIG. 9 shows an outline of the processing of the electronic control unit ECU. This will be described with reference to FIG. In Step 1,
A predetermined mode determination process is executed, and in the next step 2, it is determined whether or not the automatic steering mode is set by referring to the state of an automatic steering flag described later. Step 3 in the automatic steering mode
Otherwise, to step 13. In the automatic steering mode, first, in step 3, the electric coil 61 of the electromagnetic clutch 25 is energized to restrict the rotation of the steering wheel. In step 4, information is input from various sensors necessary for automatic steering. In step 5, the driving lane information is input from the image processing & lane detection unit 22, and in the next step 6,
A signal output from the position sensor 150 is read to input an actual steering position. In the next step 7, a target steering amount is calculated by PID control or the like based on the target steering position and the actual steering position.

In step 8, the three-position switching solenoid valve 13 is controlled to adjust the position of the piston 134, thereby adjusting the steering position. If an unadjustable state is detected such that the auxiliary steering angle does not change even if the adjustment is performed, step 21 is executed.
To release the restraint of the steering wheel, and prohibit the subsequent automatic steering.

When the automatic steering is released, the energization of the electric coil 61 of the electromagnetic clutch 25 is terminated in step 10 to release the steering wheel, and in step 11, the target steering position is set to 0 (center). The processing of steps 12, 13, 14, and 15 is repeated until the steering position reaches the target steering position.
Is set to a state in which the flow path between the control pressure of the linear pressure control valve 15 and the cylinder 132 is shut off, and the position of the piston 134 is fixed.

FIG. 1 shows the contents of the mode judgment processing in step 1.
0 is shown. This will be described with reference to FIG. In the first step 31, the state of the automatic steering flag is checked, and the automatic steering mode is checked.
It is determined whether the vehicle is in the automatic steering mode or not.
Then, the process proceeds to step 39 if the automatic steering is released. In a step 32, it is determined whether or not the changeover switch SW is off. In a step 33, it is determined whether or not the actual main steering angle detected by the main steering angle sensor 160 is out of a predetermined range A. In a step 34, the front and rear G sensor 72 is determined. In step 35, it is determined whether the actual acceleration detected by the steering torque sensor 73 is out of the predetermined range E, and in step 36, the brake switch is determined. It is determined whether or not this state is a brake-on state. In step 37, it is determined whether or not the abnormality detection circuit 75 has detected an abnormality in any of the sensors.

In step 39, the changeover switch SW
Is determined to be ON, in step 40, it is determined whether the actual main steering angle detected by the main steering angle sensor 160 is within a predetermined range B, and in step 41, the vehicle speed detected by the vehicle speed sensor 71 is determined to be within a predetermined range V. It is determined in step 42 whether or not all sensors are normal with reference to the output of the abnormality detection circuit 75. In step 43, the front and rear G sensors 72
It is determined whether or not the detected actual acceleration is within a predetermined range D.

Each range A, B, C, D, E of the above judgment conditions
And V are set in the state shown in FIG. That is,
The range B of the main steering angle indicates a state in which the input shaft operated by the driver exists near the neutral steering position, the range A indicates a slightly larger steering range, and the range D of the front and rear G is the front and rear direction. The acceleration is close to 0 and indicates a range in which the vehicle can be considered to be running at a substantially constant speed, the range C indicates a slightly wider acceleration range, and the range E of the steering torque indicates that a large force is applied to the steering input shaft. The vehicle speed range V indicates a range between a certain minimum vehicle speed (for example, 70 Km / h) and a maximum vehicle speed (for example, 100 Km / h).

In the case of the automatic steering mode, the changeover switch SW
Is ON (automatic steering ON designation), the actual main steering angle is within a predetermined range A, the actual acceleration before and after is within a predetermined range C, and the actual steering torque is a small value within a predetermined range E;
If the brake switch BK is off (non-braking state) and all sensors are operating normally, step 3
This process is completed through 2, 33, 34, 35, 36 and 37, and the automatic steering mode is continued. However, when the changeover switch SW is off (automatic steering off designation), when the actual main steering angle deviates from the predetermined range A, when the actual acceleration before and after deviates from the predetermined range C, and when the actual steering torque deviates from the predetermined range E, If the brake switch BK is ON (braking state) or if any abnormality has occurred in any of the sensors, the routine proceeds to step 38, where the automatic steering flag is cleared (into the automatic steering release state).

When the automatic steering is released, when the changeover switch SW is turned off, when the actual main steering angle is out of the predetermined range B, when the vehicle speed is out of the predetermined range V, any of the sensors is used. In the case where an abnormality occurs, or when the front and rear G is out of the range D, the state at that time is maintained,
If the changeover switch SW is turned on, the actual main steering angle is within the range B, the actual vehicle speed is within the range V, all the sensors function normally, and the front and rear G is within the range D, step 3
The program proceeds to step 44 through 9, 40, 41, 42 and 43, and sets the automatic steering flag (automatic steering ON state).
I do.

That is, even if the driver turns on the changeover switch SW to set the automatic steering mode, the steering wheel is being operated, the vehicle speed is too low or too high, or the sensor is abnormal. If the vehicle is accelerating or decelerating or decelerating, the vehicle does not immediately enter the automatic steering mode, and steps 40, 41, 42 and 43 are not performed.
When all the conditions are satisfied, the automatic steering mode is entered.
At this time, since the steering wheel is restrained in step 3 of FIG. 9, when the automatic steering is started, the main steering angle is always close to 0 (neutral state) and is controlled in the automatic steering mode. The auxiliary steering angle substantially coincides with the turning angle of the wheel.

Also, when the vehicle is running in the automatic steering mode, some dangerous condition may occur, and the driver may turn the steering wheel.
When the main steering angle deviates from the range A or the steering torque deviates from the range E, or when the depression of the brake pedal or sudden deceleration (or sudden acceleration) is detected. The automatic steering mode is automatically released, and the restraint of the steering wheel is released in step 10 of FIG.

As shown in FIG. 13, the main steering angle range A, which is a condition for releasing the automatic steering, is sufficiently wider than the main steering angle range B, which is a condition for entering the automatic steering mode. The acceleration range C, which is a condition for canceling the automatic steering, is sufficiently wider than the longitudinal acceleration range D, which is a condition for entering the automatic steering mode, so that the main steering angle and the longitudinal acceleration are slightly smaller. Automatic steering mode on / off in response to changes
There is no possibility that a hunting phenomenon such as repeated turning off occurs.

FIG. 11 shows the contents of the "steering wheel release" processing in step 10 of FIG. This will be described with reference to FIG. In step 51, the content of the register LV holding the value corresponding to the constraint torque of the electromagnetic clutch 25 is subtracted by a small value ΔL. In step 53, the value of the register LV is output to a D / A converter (not shown). This D / A converter applies an analog voltage corresponding to the value of LV to the driver 24 (see FIG. 6) as a target value. In step 54, the process waits for a predetermined time ΔT,
Proceed to step 51 again. This operation is repeated while the value of LV is positive. When the value of LV becomes negative, the process proceeds from step 52 to 53, where 0 is stored in LV and the value of LV is set to D / A.
Output to the converter.

Therefore, as shown in FIG. 12, when the restraint of the steering wheel is released, the value of LV decreases by .DELTA.L every predetermined time .DELTA.T, and the restraining force of the steering wheel gradually increases with time. To decrease. This control is performed in order to prevent the driver from feeling uneasy or disturbing the driver's senses. That is, in this embodiment, for example, when the driver operates the steering wheel, the automatic steering is released, and at the same time, the restraining of the steering wheel is automatically released.
When the restraint of the steering wheel is released instantaneously, the steering feeling (weight of the steering wheel) felt by the driver suddenly becomes lighter, and the driver feels unnecessary or drives the steering wheel too much. Operation may be incorrect. However, in this embodiment, when the automatic steering is released, the restraining force of the steering wheel is gradually reduced, so that the driver is less likely to have anxiety or make a mistake in the driving operation. The steering wheel can be operated. Therefore, for example, even when a weak woman drives an automobile, if a dangerous state occurs during automatic steering, the operation can be switched to manual operation and driving can be continued safely.

In the above embodiment, when the automatic steering is started, the restraining force of the steering wheel is instantaneously switched from 0 to the maximum (L1). At the same time, it may be changed so that the binding force gradually increases. In the above embodiment, the main steering angle is detected at the tip of the steering input shaft (near the pinion). However, the steering angle of the steering input shaft may be detected at a position close to the steering wheel. Since the steering input shaft is usually provided with a torsion bar, the detected steering angle differs between the tip of the input shaft and the vicinity of the steering wheel.

[0044]

As described above, according to the present invention, by controlling the restraining force varying means (24), the restraining means (2) is controlled.
5) The magnitude of the restraining force can be adjusted, and the restraining force control means (ECU) controls the restraining force variable means when a predetermined automatic steering release condition is satisfied in the automatic steering mode. Since the restraining force of the restraining means is gradually reduced over time, when the automatic steering is released, the weight of the steering wheel felt by the driver gradually decreases over time. For this reason, the possibility of the driver feeling uneasy due to a change in the operational feeling due to the release of the restraint of the steering wheel or the possibility of erroneous driving operation due to excessive turning of the steering wheel is extremely reduced, and safety is improved.

In the second invention, the automatic steering is canceled when the main steering angle detecting means detects a main steering amount equal to or larger than a predetermined value.
In the third invention, the automatic steering is released when the main steering torque detecting means detects a main steering torque equal to or more than a predetermined value, and in the fourth invention, the automatic steering is released when the acceleration detection means detects the longitudinal acceleration exceeding a predetermined value. In the fifth invention, automatic steering is released when a braking operation such as depression of a brake pedal is detected, and in the sixth invention, automatic steering is released when a sensor failure is detected. Also, if manual steering is urgently required during the automatic steering operation, the operation can be automatically shifted to manual steering, and the safety can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a steering mechanism of an automobile according to an embodiment.

FIG. 2 is a partial sectional view showing a right end portion of the mechanism of FIG. 1 in detail.

FIG. 3 is a partial sectional view showing a left end portion of the mechanism of FIG. 1 in detail.

FIG. 4 is a longitudinal sectional view showing the boot 180 of FIG. 2;

5 is a longitudinal sectional view showing a main shaft connected to the input shaft of FIG. 1 and a restraining mechanism thereof.

6 is a block diagram illustrating a configuration of a driver 24 in FIG.

FIG. 7 is a graph showing a relationship between a restraining torque and a current of the restraining mechanism of FIG.

FIG. 8 is a block diagram illustrating a configuration of the automatic steering device according to the embodiment.

FIG. 9 is a flowchart showing an outline of processing of the ECU of FIG. 8;

FIG. 10 is a flowchart showing the contents of step 1 in FIG. 9;

FIG. 11 is a flowchart showing the contents of step 13 in FIG. 9;

FIG. 12 is a time chart showing a change in steering restraint force.

FIG. 13 is a map showing a range of each determination condition.

[Description of Signs] 13: 3-position switching solenoid valve 21: TV camera 22: Image processing & lane detection unit 24: Driver (restraining force varying means) 25: Electromagnetic clutch 51: Main shaft 5
2: Key 53: Rotor 54: Lead wire 5
5: Spacer 56: Stay 57: Bearing 5
8: movable plate 59: friction material 60: leaf spring 6
1: electric coil 62: fixing member 63: screw 6
4: frame 71: vehicle speed sensor 72: longitudinal G sensor (acceleration detecting means) 73: steering torque sensor (main steering torque detecting means) 74: yaw rate sensor 75: abnormality detecting circuit (sensor abnormality detecting means) 82 : Lateral power shaft 8
4: Rack 91: Input shaft 92: Pinion 120R, 120L: Ball joint 122R, 122L: Tie rod 130: Hydraulic actuator 13
2: Cylinder 134: Piston 138, 140: Port 150: Sub steering angle sensor 160: Main steering angle sensor (main steering angle detecting means) 171, 172: Housing member 175: Compression coil spring 173, 174: Stopper 176: Arms 180, 191, 192: Boots 181: Boots main bodies 182, 183: Side covers 182a, 18
3a: Opening 184, 185: Hardware ECU: Electronic control unit (restraining force control means) SW: Changeover switch BK: Brake switch (braking detection means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI B62D 113: 00 119: 00 137: 00 (72) Inventor Hideki Kusunoki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation Examiner Kazumi Kawamukai (58) Field surveyed (Int. Cl. ⁷ , DB name) B62D 6/00 B62D 1/16

Claims (6)

(57) [Claims] 1. A steering input device which is operated by a driver to instruct a change in a traveling direction of a vehicle, a first steering member coupled to the steering input device to generate a displacement according to an operation amount of the device, and support of each wheel. A second steering member coupled to the shaft and changing the direction of each wheel with respect to the vehicle by moving the shaft, and an automatic drive for automatically adjusting a relative positional relationship between the first steering member and the second steering member. means,
And restraining means for engaging at least one of the steering input means and the first steering member to restrain the movement thereof;
An automatic steering control device for a vehicle, comprising: a restricting force varying means for changing the restricting force of the restricting means; and controlling the restricting force variable means when a predetermined automatic steering release condition is satisfied in the automatic steering mode. And a restraining force control means for gradually reducing the restraining force of the restraining means over time. 2. A main steering angle detecting means for detecting a steering amount of the steering input means or the first steering member, wherein the restraining force control means detects a main steering amount equal to or more than a predetermined value by the main steering angle detecting means. 2. The automatic steering control device for a vehicle according to claim 1, wherein the automatic steering is automatically released when is detected. 3. A main steering torque detecting means for detecting a magnitude of a torque applied to the steering input means or the first steering member, wherein the restraining force control means comprises:
2. The automatic steering control device for a vehicle according to claim 1, wherein the automatic steering is automatically released when the main steering torque detecting means detects a main steering torque equal to or more than a predetermined value. 4. An acceleration detecting means for detecting a longitudinal acceleration of the vehicle, wherein the restraining force control means automatically cancels the automatic steering when the acceleration detecting means detects a predetermined or more longitudinal acceleration. 2. The automatic steering control device for a vehicle according to claim 1, wherein 5. The vehicle according to claim 1, further comprising: a braking detection unit configured to detect presence or absence of a braking operation on the vehicle, wherein the restraining force control unit automatically releases the automatic steering when the braking operation is detected. Automatic steering control device for vehicles. 6. A sensor abnormality detecting means for detecting presence or absence of a failure of a sensor for detecting information necessary for automatic steering, wherein said restraining force control means automatically detects a failure of at least one sensor. The automatic steering control device for a vehicle according to claim 1, wherein the automatic steering control is automatically canceled.