JPS60178373A - Detection of obstacle in moving body - Google Patents

Abstract

PURPOSE:To attain the cost reduction in the detection of an obstacle, by arranging a plurality of distance measuring instruments each using a medium such as an ultrasonic wave on a moving body such as a moving robot and performing the detection of the obstacle to impart a running control signal to the moving body. CONSTITUTION:In a moving body in a running state, under a usual state wherein no obstacle is discovered, the signal from a control apparatus operates a distance measuring apparatuses in a front monitoring mode. When the obstacle is detected, an object is tracked by one distance measuring apparatus and the scanning range of the other distance measuring apparatus is enlarged or the subsequent trend of the tracked obstacle is detected. A running control signal necessary for the moving body is outputted to allow said moving body to avoid the obstacle. By this method, the highly practicable detection of the obstacle can be performed inexpensively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fixed number of distance detection devices using ultrasonic waves, etc. when automatically detecting obstacles, etc. in a moving body without contact using a non-contact sensor. It is common to monitor the front by installing an array, but
In this case, it is difficult to accurately grasp the position and size of the obstacles, and in particular, it is very difficult to recognize whether the obstacles are such that they require avoidance. On the other hand, when detecting obstacles using a visual sensor, there is a problem that the device is expensive and lacks practicality.

The present invention constantly monitors the detection area of an object by scanning with at least one of a plurality of distance measuring devices on a moving object, preferably all of them, and when an object is detected, all but one of the distance measuring devices are scanned. Track the object with another distance measuring device, face it, and easily attach it to the moving object.
The object of the present invention is to provide a highly practical method for detecting obstacles, which is relatively accurate, can be processed at low cost, is simple, and can be processed at high speed, using a compact, simple, and inexpensive device.

To achieve this object, the obstacle detection method of the present invention includes a plurality of distance measuring devices that non-contactly measure the distance to an object using ultrasonic waves, infrared rays, or equivalent media on a moving body. In preparation, the object detection area is constantly and generally monitored by scanning by at least one of these distance measuring devices, and the presence of the object within a certain distance from the moving body is detected by this distance measuring device. At this time, the object is tracked by other rangefinder All devices, and the vicinity of the object is scanned intensively, and necessary travel control signals are output to the moving object.

The method of the present invention will be explained in more detail below with reference to the drawings.

When detecting obstacles etc. based on the present invention, first, a plurality of distance measuring devices 2a to 2C are installed on a moving body l, as illustrated in FIGS. 1A to 1C. The above-mentioned moving object l is configured, for example, as a mobile transport station, a mobile robot, a wheelchair, a forklift, a car, etc., and is located in front of, behind, or on the side of which obstacles or other objects are to be detected. A distance measuring device is installed that measures the distance to an object in a non-contact manner using ultrasonic waves, infrared rays, or a medium equivalent to these.

Of the L distance measuring devices 2a and 2b, at least the distance measuring device 2a constantly scans the detection area of the object, that is, the scanning range at an angle of 0°, and monitors the range. When the distance measuring device detects the presence of an object within a certain distance from the moving body, based on the signal, the other distance measuring device 2b tracks the object and focuses only on the vicinity of the object. Let it scan.

When the presence of the target object is not detected, the distance measuring device 2b can also scan the entire target object detection area.

FIG. 2 shows the configuration of the distance measuring devices 2a to 2C, which are equipped with an ultrasonic transducer 10 having high directivity as a non-contact sensor. This ultrasonic transducer lO is driven via a drive circuit 13 by a drive signal output from a drive signal adjustment circuit 12 at fixed time intervals based on the clock of a clock generation circuit 11. The device outputs a transmission pulse wave, receives the reflected wave from the object 9, and sends it to the signal processing circuit 14 as a received signal. Based on the synchronization signal and the reception time signal from the signal processing circuit 14, the round trip time of the ultrasound reflected by the object 9 is calculated and the distance is converted from that time.

Note that the above-mentioned distance measuring device is generally known, and for example, a device that measures the distance to an object using infrared rays is also effective.

FIG. 3 is a diagram for explaining the configuration of an apparatus for detecting obstacles and the like based on the present invention. Note that in this device, only a single ultrasonic transducer is shown, and the others are omitted. In addition, although the distance A11ll device is shown for the case where the device performs general scanning of the target object detection area and tracking of the target object, if the distance measuring device has only one of these functions, unnecessary parts may be removed. Of course, it can be omitted.

To explain this diagram, the ultrasonic transducer lO, which together with the distance detection circuit 31 constitutes the distance measuring device shown in FIG. The rotary shaft 23 is connected to the motor 21 through a gear train 24, etc. for detecting angles.As the motor 21, a small servo motor, pulse motor, etc. The rotation angle of the motor 21 is controlled by detecting the rotation angle of the transducer 10 in the motor 21 with the potentiometer 25 and feeding it back to the motor drive circuit 32 mainly composed of a servo amplifier.

The sensor scanning device 33 receives a signal of the rotation angle of the transducer 10 as feedback from the potentiometer 25, and
A control signal from the control device 34 causes the necessary oscillation of the transducer 1o in the monitoring mode, that is, the motor 21, to a certain angle range 40 corresponding to the detection area of the object. For example, when this obstacle detection device is used to monitor the front of a moving body, the scanning angle signal for reciprocating the moving body is output to the motor drive circuit 32. A scanning angle signal in a normal forward monitoring mode that uniformly scans the area is output. This sensor scanning device 33 is connected to a distance measuring device that scans the entire detection area of the object, and does not need to be attached to a distance measuring device that only tracks the object.

Further, the object tracking device 35 receives a signal of the rotation angle of the transducer 10 as feedback from the potentiometer 25, further receives a signal of the distance to the object from the distance detection circuit 31, and receives a signal from the control device 34 or the object. The motor drive circuit 32 is configured so that when the presence of the object is confirmed by the control signal from the object movement vector calculation device 36, the transducer 1O focuses on scanning the vicinity of the object while tracking the object. In contrast, the scanning angle signal of the tracking mote is output. This object tracking device 35 does not need to be installed in any number of stages compared to a distance measuring device that only has the function of constantly and generally monitoring the detection area of the object.

An obstacle existence detection device 37 connected to a distance detection circuit 31 of a distance measurement device that monitors the object detection area in general,
The distance signal sent from the distance detection circuit 31 to the obstacle is constantly monitored, and when the distance signal becomes higher than a certain value, or a sudden change in the distance, especially a rapid decrease, is detected. It has a function of detecting the approach of an object, and when the presence of an obstacle is detected, the control device 3 operates a distance measuring device that tracks the object.
A control signal is output to an object tracking device 35 connected to the distance measuring device via the distance measuring device 4.

In addition, when the object position and dimension detection device 38 receives the detection signal from the obstacle existence detection device 37, the object position and dimension detection device 38 detects a distance to track the object (the distance to the obstacle obtained from the measuring device and the distance recorded). The position and size of the object are detected by data on the angle range of obstacle detection obtained from the output of the measuring device and the potentiometer 25.

1. The object movement vector calculation device 36, which is connected as necessary to the object position and dimension detection device 38, calculates the distance to the obstacle and the obstacle detection output from the J method detection device 38 at the above position. The moving direction and speed of the obstacle in absolute coordinates are calculated from the variation in the angular range, and the calculated values are output to the control device 34 and the object tracking device 35.

In addition, the control device 34 controls the operations of the devices described above, and further controls the sensor scanning device 33 based on the appearance of the obstacle existence detection device 37, the object position and dimension detection device 38, etc.
It also controls the operation of the object tracking device 34.

Detection of obstacles etc. by a device with such a configuration is as follows:
This is done under the conditions described below.

When a moving object is running and no obstacles are found, the control device 34 sends a signal to the sensor scanning device 3.
A control signal is sent to the rangefinder Jll device (Fig. 1A) that monitors the object detection area in general.
2a, 2b in -C) (7) Motor drive circuit 3
2 is operated in forward monitoring mode, and the ultrasonic transducer 1o is moved within a certain angle range θ by the motor 21. It will rotate back and forth.

When the presence of an obstacle is detected by the obstacle detection device 37, a control signal from the control device 34 is connected to a distance measuring device (2b in 11'a A-C) that tracks the object. The signal is sent to the object tracking device 35, which drives the motor 21 to cause the transducer 10 to track the object, and scans the vicinity of the object intensively to determine the object position = The J method detection device 38 recognizes the position, size, etc. of the object.

Therefore, when an obstacle or the like is detected according to the two consecutive steps, necessary travel control information is output to the moving object.

When detecting obstacles etc. in this way, for example, when two distance measuring devices 2a and 2b are provided as shown in FIG. 1A, one distance #1 measuring device 2b detects obstacles etc. When tracking is performed, the scanning range of the other distance measuring device 2a can be expanded as shown in FIG.

Furthermore, as shown in FIG. 1C, if the distance measuring device M2C is installed on the side of the moving body 1, it can of course be used to detect obstacles on the side, but as shown in FIG. As you can see,
It can also be used to detect the subsequent movement of an obstacle tracked by the distance measuring device 2b.

, As shown in FIGS. 1B and C, when three or more distance measuring devices are arranged facing the object detection area, two or more of the distance measuring devices, that is, the distance measuring device When an object is tracked by the devices 2b and 2b, the position and size of the object can be accurately detected, but when separate obstacles are discovered one after another, the It is also possible to use a single distance measuring device (see FIG. 5), which allows the moving object to drive safely while avoiding many obstacles.

Further, as shown in FIG. 6, a pair of distance measuring devices 2b and 2c provided at the front and rear sides of the moving body 1 are used to determine the distance between the moving body 1 and the side wall 40 of the passage and the relationship with the side wall 40. In this case, if the existence of intersections in the passage, irregularities on the side wall 40, etc. and their positions are stored as a map in the storage device on the mobile body, the posture of the vehicle can be detected while the vehicle is moving. The position of the moving body can be confirmed by comparing the unevenness of the side wall with the map, and the front and rear range finder mill devices 2b and 2c can check the position of the moving body while controlling the distance to the station etc. to be the same. By approaching that station,
Tonking of the mobile to the station can be performed.

Further, as shown in FIG. 7, a moving object as shown in FIG. 1C can be caused to follow another moving object 1a by using the moving object 1a as an object to be detected. In this case, in the moving body 1, the presence of the moving body 1a in front is confirmed by the distance measuring device 2a, and the left and right distance M i (between the moving body 1a in front and detected by the measuring devices 2b, 2b) is determined. The moving object 1 in front travels while keeping approximately the same distance and is detected by the left and right distance measuring devices 2b, 2b.
The curve is detected by the change in the distance between the moving body 1 and the side wall 4.
Detect the corner of o.

As detailed above, according to the detection method of the present invention, it is possible to detect obstacles with relatively high accuracy using a small, simple, and inexpensive device that can be easily attached to a moving object. .

[Brief explanation of the drawing]

1A to 1C are schematic configuration diagrams of a moving body that detects objects based on the present invention, FIG. 2 is a block configuration diagram of a distance measuring device, and FIG. FIGS. 4 to 7 are diagrams illustrating the detection pattern t of obstacles, etc. on a moving body. 1...moving object, 2a-2c...5 to distance measuring device 6
1 Figure A B 'C 7, r, a 2 Figure 6 x″iJ ?, 'E: 7 II

Claims (1)

[Claims] 1. Equipped with a plurality of distance measuring devices on a moving body that non-contactly measures the distance to an object using ultrasonic waves, infrared rays, or a medium equivalent to these, and using at least one of these distance measuring devices. When the object detection area is constantly and generally monitored by scanning, and the presence of the object within a certain distance from the moving body is detected by this distance measuring device,
A method for detecting obstacles, etc. in a moving body, characterized by scanning the vicinity of the object in an east-point manner while tracking the object with another distance measuring device, and outputting a necessary travel control signal to the moving object.