JPH1138140A - Method for adjusting center axis of radar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely make the optical axis of radar agree with the advancing direction of a vehicle. SOLUTION: In a plant, VSC(vehicle attitude stabilizing device) inspections S101, suspension adjustment S102, toe adjustment S103, head lamp adjustment S104, etc., are carried out on a vehicle after the vehicle is assembled, but optical adjustment is performed during the toe adjustment S103 for making the optical axis of laser radar agree with the body center of the vehicle immediately after the advancing direction of the vehicle agrees with the body center. The optical axis adjustment is performed by visualizing the center beam of scan laser radar by only making the center beam brighter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adjusting the optical axis of a radar, and more particularly to a method of aligning the optical axis of a laser beam emitted from a radar during vehicle inspection with the traveling direction of a vehicle.

[0002]

2. Description of the Related Art When a preceding vehicle or the like is detected by using a laser radar, it is necessary to correctly adjust the optical axis of the laser radar as a precondition. For example, JP-A-4-242899
Japanese Patent Application Laid-Open Publication No. H11-157, discloses a technique for adjusting the optical axis by emitting a laser beam whose power has been reduced when the vehicle is stopped.

[0003]

However, even if the adjustment is made so that the optical axis of the laser radar coincides with the center axis of the body (body), if the body center axis does not coincide with the vehicle traveling direction, the vehicle travels. Sometimes it is not possible to correctly detect a preceding vehicle.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a method for easily and surely making the optical axis of a laser radar coincide with the traveling direction of a vehicle. is there.

[0005]

According to a first aspect of the present invention, there is provided a method of adjusting an irradiation center axis of an on-vehicle radar, the method comprising the steps of: The center axis of the radar and the vehicle traveling direction are matched.

In a second aspect based on the first aspect, the center optical axis of the radar is the center optical axis of the laser scanned by using a polygon mirror, and is aligned with the center position of the polygon mirror surface. The laser beam is emitted to adjust the center optical axis of the radar.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the relationship between the vehicle advancing axis and the vehicle body (body) center axis. Normally, these axes must coincide, but it is possible that both axes may not coincide. On the other hand, when the laser radar 10 is mounted, the laser radar 10 is assembled based on the center axis of the body.
If the vehicle traveling axis does not coincide with the body center axis, the traveling direction of the vehicle does not coincide with the optical axis of the laser radar 10, and as described above, a deviation occurs in the detection of the preceding vehicle during actual traveling. Will be. The purpose of this embodiment is
The purpose is to make the optical axis of the laser radar 10 correctly coincide with the traveling direction of the vehicle.

FIG. 2 shows a part of an inspection process performed on a vehicle at the time of shipment from a factory. VSC on vehicle
When the (vehicle attitude stabilizing device) is mounted, the operation of this VSC is checked first (S101). VS
Specifically, when the vehicle has a strong tendency to oversteer or understeer, the engine output is reduced and a braking force is applied to the front wheels or the rear wheels to secure the stability of the turning motion of the vehicle. Then, suspension adjustment is performed (S102), and the process proceeds to a toe adjustment step of adjusting a toe angle which is an angle between the direction of the front wheels of the vehicle and the center line of the vehicle (S103). In this toe adjustment step, the wheel alignment of the assembled vehicle is adjusted. Specifically, the toe-in, camber angle, caster angle, and kingpin tilt angle are adjusted to make the vehicle traveling direction coincide with the body center axis.

After that, the process proceeds to headlamp adjustment (S104). In the present embodiment, in this toe adjustment step,
Execute the radar optical axis adjustment.

FIG. 3 shows a system configuration for adjusting the optical axis of the laser radar 10 after the toe angle adjustment is completed in the toe adjustment step. The vehicle is supported by a toe angle adjusting tote tester 214, and a CCD camera 216 including a CCD sensor is arranged in front of the laser radar 10 at the same height as the laser radar 10. The CCD camera 216 is provided so as to be slidable on a rail 218, and can be stopped particularly at a position A near the vehicle and at a position B far from the vehicle. The rail 218 is a totester 2
4 is provided along the traveling direction of the vehicle adjusted by 4, that is, along the center line of the vehicle. In addition, the rail 218 is
One or a plurality may be used, and various shapes may be employed.

The CCD camera 216 is connected to the rail 21.
While being slidably mounted on the carriage 8, the movement can be adjusted in the height direction and in a direction perpendicular to the vehicle (vehicle width direction). Therefore, on rail 218, CC
By adjusting the position of the D camera 216, the CCD camera 216 can be adjusted so as to be located in front of the laser radar 10. Note that the CCD camera 216 only needs to move in two axes, X and Y, in a plane perpendicular to the vehicle, and various types of moving mechanisms can be employed. Also, by the CCD camera 216 sliding on the rail 218,
The vehicle moves in front of the laser radar 10 in the traveling direction of the vehicle while maintaining a constant height. Furthermore, CCD camera 2
A personal computer 220 is connected to the PC 16, and imaging data obtained by the CCD camera 216 is transferred to the personal computer 220.
, Where the image is processed. A display 222 is connected to the personal computer 220.
The image processed at 20 is displayed here. That is,
Laser radar 10 obtained by CCD camera 216
Is displayed on the display monitor 222.

In such a device, in order to adjust the optical axis of the laser radar 10 attached to the vehicle, after adjusting the wheel alignment, the control device of the vehicle is put into a factory optical axis adjustment mode by a special operation. FIG. 4 shows an example of a block diagram of the entire configuration of the vehicle. Specifically, the cruise control switch 18 and the brake are simultaneously operated to light the headway control ECU (electronic control unit) 12 and the engine ECU 14. Set to axis adjustment mode. At this time, the content indicating that the optical axis adjustment mode has been set is displayed on the display 40, and the alarm buzzer 32 is driven to check the operation of the alarm buzzer 32. Next, only the center beam of the laser radar 10 that scans a predetermined range is emitted. FIG. 5 schematically shows a scan range 100 of the laser radar 10 in the present embodiment. As described above, the laser radar 10 is provided at a front portion (for example, a bumper portion) of the vehicle, and emits a laser beam forward. Specifically, the pulsed laser light emitted from the light emitting unit in the radar 10 is reflected by the rotating polygon mirror and transmitted to the front of the vehicle. Scanning is performed in the left and right direction by reflecting on a rotating surface among the six surfaces of the polygon mirror, and scanning is performed in the vertical direction by reflecting on another surface having a different inclination angle. When adjusting the optical axis of the laser radar 10, the center beam of the scan range 100 may be made to coincide with the traveling direction of the vehicle, so that the laser beam is emitted in accordance with the center position of the polygon mirror surface. Generates a center beam.

Next, at the position A, the CCD camera 216
Of the laser radar 10 by adjusting the position of the
Is adjusted so that the light receiving spot of the center laser beam from the display monitor 222 is located substantially at the center position. After this adjustment, the personal computer 220 stores the light receiving spot position of the laser beam on the CCD camera 216. Note that the rail 218 itself may be movable. And CC
The D camera 216 is slid on the rail 218 and moved to the position B away from the vehicle. The distance L between the A position and the B position is set to, for example, 400 mm. Then, the personal computer 220 stores the light receiving spot position of the laser beam at the position B.

When the optical axis of the laser radar 10 is set correctly, the spot position at the position A and the spot position at the position B become the same. However, if the installation position of the laser radar 10 is shifted, the two light receiving spots will be shifted. For example, if the optical axis of the laser radar 10 is shifted by θ, the difference between the light receiving spot position at the position A and the light receiving spot position at the position B is δ = θ · L, and the position of the light receiving spot is δ.
Just shift. Therefore, if the shift δ is measured, the shift θ of the optical axis can be calculated by θ = tan ⁻¹ (δ / L). Therefore,
With the light receiving spot at the point A and the current light receiving position at the point B displayed on the display monitor 222, the respective bolts for the vertical and horizontal adjustments of the laser radar 10 are adjusted to change the current light receiving spot position at the point A to the light receiving position. The optical axis can be adjusted by matching the spot position.

If the displacement of the laser radar 10 is large, the light receiving spot at the position B may be off the display monitor 222 in some cases. In such a case, the movement of the CCD camera 216 on the rail 218 is stopped before reaching the position B (the position where the light-receiving spot position is displayed), where temporary adjustment is performed, and then the position is moved to the position B. It is preferable to perform the adjustment again. Even if the CCD camera 216 does not move on the rail 218, a condensing lens is disposed between the CCD 216 and the light source of the laser radar 10 to monitor the shift amount of the point condensed on the CCD. Optical axis adjustment may be performed.

FIG. 6 is a schematic diagram showing the case where the optical axis is actually adjusted at a factory. The operator enters the work space and adjusts the optical axis of the laser radar 10 while watching the display monitor 222.

When the optical axis adjustment mode is set, there is an effect that all input / output and communication of the elements constituting the system shown in FIG. 4 can be checked.
For example, the engine ECU 14 that has received the cruise control switch 18 and the brake operation input determines that the mode is the optical axis adjustment mode, and transmits a function code representing the mode to the following distance control ECU 12, and as a result, the function of the laser radar 10 from the following distance control ECU 12 also functions A code is sent, instructing that only the center beam be emitted. The engine ECU 1
4 at the same time as giving an instruction to display the display 40 via the multiplex communication 34, the VSC-ECU 2
8 is also instructed to sound an alarm. As described above, in order to enter the optical axis adjustment mode, input / output and communication of each element must be normal, so that a system check can be easily performed.

The above description is for the case where the optical axis is adjusted in a factory equipped with facilities, but it may be necessary to adjust the optical axis with a dealer without the facilities. In this case, since the toe adjustment is impossible, it is necessary to simply extract the vehicle center line by some method and match the vehicle center line with the center beam of the laser radar 10. At this time, it goes without saying that the wheel alignment is adjusted before the adjustment of the optical axis.

FIG. 7 shows a front portion (A) and a rear portion (B) of the vehicle. Generally, a vehicle is provided with marks (emblems) 11a and 11b at the center of a front portion and the center of a rear portion, respectively. Therefore, the vehicle is placed on a horizontal surface, and the marks 11a on the front and rear portions are provided.
Threads with suspended weights are respectively drawn vertically from 11b and 11b, and the floor is marked. By connecting these marks formed on the front and rear floors, the vehicle center line can be easily extracted.

After extracting the vehicle center line in this way,
The target is placed at the same height position as the laser radar 12 (xm), which is an extension of the vehicle center line and about 20 m ahead of the vehicle. FIG. 8 shows an example of the target used, and FIG. 9 shows a plan view when the target is arranged at a position 20 m ahead of the vehicle. With respect to this target, all the beams of the laser radar 10 are made to emit light to detect the position of the target, and the shift amount of the optical axis is calculated. As shown in FIG. 10, the dedicated diagnostic tool 300 is connected to the vehicle via a connector, and the diagnostic tool 300 is connected.
The shift amount is displayed in real time, and the operator adjusts the optical axis of the laser radar 10 so that the displayed shift amount becomes zero. Accordingly, even at a dealer, the optical axis of the laser radar 10 can be easily and reliably aligned with the vehicle center line. It should be noted that a personal computer other than the diagnostic tool 300 may be appropriately used to monitor the amount of deviation.

[0022]

As described above, according to the present invention,
The optical axis of the sensor can be simply and reliably aligned with the traveling direction of the vehicle.

[Brief description of the drawings]

FIG. 1 is a plan view showing a relationship between a vehicle traveling axis and a body center axis.

FIG. 2 is a processing flowchart according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of a factory optical axis adjustment system of the embodiment.

FIG. 4 is a configuration block diagram of a vehicle according to the embodiment.

FIG. 5 is an explanatory diagram of a scan range of the laser radar according to the embodiment.

FIG. 6 is a work explanatory diagram at the time of factory optical axis adjustment of the embodiment.

FIG. 7 is an external view of a front portion and a rear portion of the vehicle.

FIG. 8 is an external view of a target.

FIG. 9 is a plan view showing a target arrangement position.

FIG. 10 is an explanatory diagram showing an example of using a dedicated diagnostic tool.

[Explanation of symbols]

10 laser radar, 12 inter-vehicle control ECU, 14 engine ECU, 40 display, 220, personal computer,
222 display monitor.

Claims (2)

[Claims] 1. A method for adjusting an irradiation center axis of an on-vehicle radar, wherein in a toe angle adjustment step of a vehicle, the center axis of the radar coincides with a traveling direction of the vehicle after the toe angle adjustment. Center axis adjustment method. 2. A central optical axis of the radar is a central optical axis of the laser scanning by using a polygon mirror,
2. The method according to claim 1, wherein a laser beam is emitted in accordance with a center position of the polygon mirror surface to adjust a center optical axis of the radar.