JPH03105207A - Position detecting apparatus for moving object - Google Patents

Abstract

PURPOSE:To detect and measure the position and an angle of attitude of a moving object in a simple structure by placing a light reflecting means along a predetermined path, scanning the light reflecting means, and calculating the position and angle of attitude of the moving object from the scanning angle when the reflecting light is detected. CONSTITUTION:A light beam projected from a light beam generating means 11 is reflected by a reflecting means 12 which is reciprocated within a predetermined distance. Light beam scanning means 1, 2 are provided with the means 11, a motor 13 equipped with an encoder, a mounting plate 12 and a reflecting light detecting means 14. These means 1, 2 are placed in front of and in the rear of a moving object, respectively. A light reflecting means 3 is provided at every predetermined distance over a path of the moving object. Scanning information from the front light beam scanning means 1 and rear light beam scanning means 2, that is, alphaf and alphar are input to an operating means 4. These scanning informations alphaf and alphar are comprised of scanning angle information and reflecting light detecting signals. The distance df or dr between the means 3 and 1 or 2, distance (d) between the path and the center of the moving object and angle of attitude are obtained by the operations in the means 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a device for measuring the position and attitude angle of a mobile object that moves by autonomous guidance along a predetermined route. [Prior Art] Various methods have been proposed for moving a moving object such as an automatic guided vehicle along a predetermined route.

For example, there is a method shown in FIG. This involves protruding a screen A from the floor F at an arbitrary position along a predetermined travel path of the moving object C, arranging a mark M on the inner surface of this screen 8, and installing an optical displacement sensor B on the moving object C side. A position/azimuth calculation device D is installed to detect the position and orientation of the signal from the optical displacement sensor B. On the side of the moving body C, optical sensors B. B is installed, and the screens are also paired so that these two optical displacement sensors face each other at the same time, and the distance L between the two optical displacement sensors is made equal to the distance L between the two screens. The distance between the reference position of the travel path and the mark is appropriately determined so that the side surface of the traveling moving object does not come into contact with the screen and so that measurement can be performed reliably using the optical displacement sensor.

[Problem to be solved by the invention]

Therefore, measuring the distance to a position mark using an optical displacement sensor can provide the accuracy necessary to correct the deviation from the route due to autonomous driving, but it is also possible to measure the distance with a position mark using an optical displacement sensor. Walls or screens installed along the travel route. In addition, since the detection distance of the optical displacement sensor is short, it is necessary to provide a wall at a position approximately 100+w from the side of the moving body. For this reason, if there is no wall on the running floor surface, or if there is a wall but it is far away from the path of the moving object, it is necessary to install a mark pasting screen on the floor close to the moving object moving along the path. be. In addition, such a screen results in a protrusion on the floor surface, which obstructs the passage of other moving objects and people, and furthermore, it has drawbacks such as the risk of collision with moving objects. The conventional method of moving along a route stored in memory using guidance using autonomous position measurement had the disadvantage that if the error in autonomous position measurement became large, the actual route of travel would deviate from the set route. In order to prevent this and improve the accuracy of position measurement, expensive equipment such as a gyro is required.

Or, another position measurement device is required to correct the error. The present invention has a simple structure, and aims to measure the position and attitude angle of a moving object with respect to a route, and to accurately travel along the route. [Means for Solving the Problems] The present invention has been made to achieve the above object, and includes a light reflection means installed on a path and reflecting light in the incident direction, and a light beam generating means provided on the moving body side. means, a light beam scanning means for scanning the light beam in a plane orthogonal to the center line of the moving body, a reflected light detection means provided in connection therewith, and detecting the scanning angle of the light beam when the reflected light is detected. The present invention is characterized in that it has a plurality of sets of means for detecting reflected light, and a calculation means for calculating the position and attitude angle of the moving body from the scanning angle at the time of detecting the reflected light of each set. [Function] Two light reflecting means that reflect light in the incident direction are installed as one sheath at a certain interval along a predetermined path, and two light beams are set at the center of the moving body side. By the scanning means,
The position and attitude angle of the moving body with respect to the path are measured by scanning each light reflecting means and from the scanning angle of each light beam scanning means when the reflected light can be scanned. [Example] The present invention will be explained below based on the illustrated example. In the figure, C is a moving object such as an automatic guided vehicle, which autonomously travels along a predetermined path on the floor F using a drive device and running wheels mounted on the moving object, and also runs along the center line of the moving object. Light beam scanning means 1.2 are provided at two positions, front and rear.
The light beam scanning means 1 and 2 are located at the center O in the longitudinal direction of the moving body.
Equal distance from a. Position it above a. The light beam scanning means 1.2 scans the light beam on a plane that intersects the line OL passing through the center of the moving body at a known angle β.

Further, when the mobile object C autonomously moves along a predetermined route, it may be placed along the route along the route, for example, on the ceiling surface. Light reflecting means 3 are arranged at predetermined intervals. The light reflecting means 3 is used to reflect the light emitted from the light beam scanning means 1.2, that is, to reflect the light in the direction of the incident light. The light beam scanning means, as shown in FIG. 4, reflects the light beam emitted from the light beam generating means l1 on a reflecting plate 12 which is repeatedly rotated by a motor l3 at fixed intervals using an encoder. The light beam emitted from the light beam generating means l1 is reflected by this reflecting plate l2. At this time, since the reflector is repeatedly rotated through a certain angle, the light beam is scanned in a direction perpendicular to the longitudinal axis of the reflector mounting shaft. Light beam scanning means 1. 2 includes a light beam generating means 1;
1. In addition to a motor l3 with an encoder and a mounting plate 12, a reflected light detection means 14 is provided, and this means is connected to a moving object C.
are installed at the front and rear of the At this time, when the light beam reflecting means 3 is provided on the ceiling surface, the light beam scanning means 1.
2 is also installed on the top surface of the moving body and in a position where the light beam is not blocked by other equipment on the moving body. The moving body C is equipped with a calculation means 4, and the calculation means 4 manually inputs the front scanning information αf from the front light beam scanning means 1 and the rear scanning information αr from the rear light beam scanning means 2. Ru. This scanning information αf, αr is transmitted to the encoder 1 provided on the motor.
5 and a reflected light detection signal detected by reflected light detection means 14.

When the scanning information αf, αr is input to the calculating means 4 in this way, the front distance calculating circuit 4l and the rear distance calculating circuit 42 calculate the distance between the light reflecting means 3 and the light beam scanning means l or 2. Hdf. dr is calculated. This is light reflecting means 3
It is obtained from the equation df = h tanaf from the height difference h of the light beam scanning means 1 and the scanning angle αf when the reflected light is detected.

Similarly, the distance fidr between the rear light beam scanning stage 2 and the light reflecting means 3 is determined from dr = h tanar.

This distance df. The method for determining dr is shown in FIG.

Further, the distance d between the path and the center of the moving body and the attitude angle θ are determined by the formula shown in FIG.

Therefore, when the moving body C travels along a predetermined path, when the front and rear light beam scanning means 1 and 2 scan the light beam, the scanning means and the light beam reflection means control the forward scanning angle αf. Then, the backward scanning angle αr is detected. This is always performed while the moving body C is moving, and the position and attitude angle are calculated by the calculation means 4 using the detection signals, respectively, and the running direction and position of the moving body are detected. Note that the position coordinate calculation is performed using Xv=X. +d.

As a result, the movable body C detects errors in the running direction and position route, corrects the running direction, and moves accurately along the route.

Although a right angle is simple as the above-mentioned known angle, any angle can also be measured by geometric calculation.

〔Effect of the invention〕

In the present invention, two light reflection means for reflecting light in the incident direction are installed at a certain interval along a predetermined path, and two light beams are provided at the center of the moving object. The scanning means scans each light reflecting means, and the position and attitude angle of the moving body with respect to the path are measured from the scanning angle of each light beam scanning means when the reflected light can be scanned. By placing a pair of light reflecting means along the path, the position and attitude angle can be measured, and if the position measurement error is corrected using this, deviation from the path can be prevented even with a simple and inexpensive autonomous position measurement method. It has the advantage of being able to prevent

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a moving body moving along a path, v. 2
The figure is an explanatory diagram for calculating the distance between the light reflection means and the light beam scanning means, Fig. 3 is an explanatory diagram for calculating the distance and angle, Fig. 4 is an explanatory diagram for the light beam scanning means, and Fig. 5 is an explanatory diagram for calculating position coordinates. FIG. 6 is an explanatory diagram of the calculation flow, and FIG. 7 is an explanatory diagram of a known example. C is a moving body, 1.2 is a light beam scanning means, 3 is a light beam reflection means, and 4 is a calculation means.

Claims (1)

[Claims] (1) In a mobile object that autonomously moves along a preset path, a light reflecting means is installed on the path and reflects light in the incident direction, and a light beam generating means is provided on the mobile object side. a light beam scanning means for scanning the light beam in a plane intersecting at a known angle with respect to the center line of the moving object; a reflected light detection means provided in connection therewith; and a light beam scanning means for scanning the light beam when detecting the reflected light. 1. A position measuring device for a moving object, comprising a plurality of sets of means for detecting angles, and calculating means for calculating the position and attitude angle of the moving object from the scanning angle at the time of detecting reflected light of each set.