JPS6111817A - Carrying device - Google Patents

Abstract

PURPOSE:To detect a guide mark highly accurately and rapidly by picking up an optional area including the guide mark by a two-dimensional image pickup and coding an output integrated in each main scanning line into a binary value to calculate the positional shift of a moving position from the guide mark. CONSTITUTION:In the carrying device, the two-dimensional image pickup such as an ITV camera is used as a detector for a guide mark 3 and the main scanning direction of the image pickup 10 is set so as to coincide with the moving direction of a truck. A signal AS obtained by picking up a prescribed range (a) icluding the guide mark 3 is intergrated in each main scanning line by an integrating circuit 11 and encoded into a binary value in acccordance with a prescribed signal level previousy set up by a binary-coding circut 12 and the binary value is stored in a momory 13. The binary-coded output signal CS is sampled by a sampling signal ES outputted fron a movement control circuit 14, and the storage of the sampling binary signal for one picture, the sampling binary signal is red out to detect the position of the guide mark 3 and decide its shape. The shift value is calculated from said position and shape data and a control signal is outputted to a steering driving circuit 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a conveyance device that automatically moves along guide marks.

[Technical background of the invention]

In recent years, with the automation of various processes such as assembly processes on semiconductor and electronic device manufacturing lines, automatic transport systems are used to transport parts between each process or to supply parts to each process. That is what is being attempted. This type of system is generally configured to display a belt-shaped guide mark on a conveyance path, and to move the conveyance device along the mark by detecting the guide mark. Figure 1 shows an example of the external appearance of the transport device.A manipulator 2 for transferring parts is installed on a trolley 1 that can be driven by a motor, and guidance marks are placed on the front and rear ends of the bottom of the trolley 1. A detector 4 for detecting 3 is provided. Note that 5 is a component placed on the trolley 1.

By the way, as a means for detecting the guide mark 3 of such an apparatus, conventionally, for example, a -dimensional optical sensor 6 as shown in FIG.
The sensor 6 generates a one-dimensional image across the guide mark 3 as shown at L1 in the figure as the trolley 1 moves.
``Detection at regular intervals and guide mark 3 from these detected images
A device that detects the relative position of the trolley 1 and the moving position of the trolley 1, and a two-dimensional imager 7 such as an industrial television camera <I'TV camera) as a detector as shown in FIG.
Using this two-dimensional imager 7, an arbitrary area including the guide mark 3 is imaged, the guide mark 3 is detected from the captured image by pattern recognition 11kffi, etc., and the position of the trolley 1 with respect to the guide mark 3 is determined from the detection result. A device is known in which the movement position of the trolley 1 is corrected based on the deviation.

[Problems with Background Art] However, each of these conventional devices has the following drawbacks. In other words, in general, this type of conveyance system partially narrows the width of the guide mark or cuts the mark and recognizes this as deceleration or stop information◆
However, in such a case, the one using the above-mentioned -dimensional optical sensor 6 performs signal processing on each -dimensional image individually to determine the position of the guide mark 3.

When the guide mark 3 is partially soiled or peeled off, this is often mistakenly recognized as the deceleration or stop information, resulting in low detection accuracy.

On the other hand, in the case of using the two-dimensional imager 7, the position of the guide mark 3 is detected by pattern recognition for each imaging area, so any defects in the mark such as dirt or peeling can be mistakenly interpreted as deceleration or stop information. Detection defects are unlikely to occur, and as a result, detection accuracy can be set high.

However, on the other hand, in order to recognize the guidance mark, all the imaging signals for one screen must be processed, so it takes a lot of time to obtain the position control information, and as a result, the moving speed of the trolley 1 has to be increased. could not be standardized. Further, since it is necessary to perform complex image processing such as the above-mentioned pattern recognition, and also to remove dirt, peeling, etc. by image processing, there is a drawback that the circuit configuration and control become complicated.

[Purpose of the invention]

The present invention makes it possible to detect the guidance mark with high precision (even straining force 1) at high speed without being affected by defects in the guidance mark, and to realize this with a simple configuration. The purpose is to provide a conveyance device.

[Summary of the invention]

In order to achieve the above object, the present invention installs a two-dimensional imager so that the main scanning direction is in the same direction as the conveyance movement direction, and thereby images an arbitrary area including the guide mark,
The image signal obtained by this is integrated for each main scanning line, and the integrated output is converted into a binary value (hi).These binary outputs are selectively stored in a storage circuit and output from these binary outputs. Calculate the displacement of the movement position with respect to the guide mark and set the movement position i
It was designed to be controlled.

(Embodiment of the Invention) FIG. 4 shows a main part configuration of a conveying device in an embodiment of the present invention. This device uses a two-dimensional imager 10 such as an ITV camera as the guide mark 3 detector, and as shown in the figure, the main scanning direction of the two-dimensional imager 1o coincides with the moving direction (arrow A) of the cart 1. It is set up like this. Then, the two-dimensional imager 10 images a predetermined range A including the guide mark 3, and the image signal As is sent to the integrating circuit 1.
1, the integration circuit 11 integrates each main scanning line, and then the integrated output BS is binarized according to a predetermined signal level 8m set in advance by the binarization circuit 12, and this binarized output C8 is introduced into the memory 13. This memory 13 is composed of a serial input/parallel output type shift register that stores the number of bits for the main scanning line, for example, and transfers the binarized output signal O8 from the binarization circuit 12 to a movement control circuit 14 (to be described later).
The sampling value DS is obtained by sampling at the rear end of each main scan according to the sampling signal ES generated from the
Shift input sequentially. The movement control circuit 14 has a microprocessor as a main control unit, and outputs a sampling signal ES to the memory 13 at the rear end of each main scan, and also outputs a sampling signal ES for one screen to the memory 13, and converts the sampling signal for one screen into binary data to the memory 13. At the time when the signal DS is stored, these sampling binary signals DS are read out to detect the position of the guide mark 3, to detect the position of the guide mark 3, and to determine the form of the guide mark. Then, the deviation amount of the moving position of the trolley 1 with respect to the guide mark 3 is calculated from the above-mentioned device detection result, and a position control signal set to make this deviation amount zero is output to the steering drive circuit 15. Further, the movement control circuit 14 generates a movement control signal for controlling movement operations of the trolley 1 such as constant speed movement, deceleration movement, or stopping according to the determination result of the form of the guide mark 3, and outputs it to the steering drive circuit 15. do.

With this configuration, while the cart 1 is moving, the guide mark 3 is imaged by the two-dimensional imager 10 with the moving direction of the cart 1 as the main scanning direction, and the image signal As is as shown in FIG. The integration circuit 11 integrates each main scanning line. At this time, the image signal As obtained by imaging the guide mark 3 becomes a high level as shown by X in the figure, and the other parts,
The signal obtained by capturing the image will be at a low level like Y. For this reason, the final level of the integral ratio 88 is also high when the image signal of the guide mark 3 is integrated, and is at a constant level when the other parts are imaged. The integral output B obtained in this way
S is supplied to the binarization circuit 12 and binarized there. At this time, the binarization level SL is set so that all the integral outputs except for the integral output of the image pickup signal Y obtained at a portion other than the guide mark 3 can be detected as shown in FIG. Therefore, the image signal of the guide mark 3 can be reliably detected by the above-mentioned binarization, and even if the guide mark 3 is dirty or peeled off, the image signal may have signal loss as shown in 2 in Fig. 5, for example. Even so, this signal loss is eventually erased by the above-mentioned integration processing and binarization, and is detected as a guide mark representing constant speed movement. Thus, the above-mentioned integration processing and binarization processing prevent erroneous detection due to defects in the guide mark 3. Note that the regular guide mark for deceleration control has a notch 3a that is set to be long enough to occupy almost the entire imaging area as shown in FIG. The integrated output level of the imaged signal is approximately equal to the integrated output level of Nobuaki obtained by imaging the portion other than the guide mark 3, and therefore, when binarized, it is detected that there is no guide mark. In other words, even if the integral processing is performed, the regular guide marks for deceleration control can be reliably detected without any detection omissions.

The binarized signal C8 for each main scan output from the binarization circuit 12 is sampled and then shifted into the memory 13 in order, and when one screen's worth is stored, it is input into the movement control circuit 14. Ru. As a result, the movement control circuit 14
As described above, the position of the guide mark 3 in the image capture screen is detected from the sampling binary signal DS, the form of the guide mark 3 is determined, and the movement position of the trolley 1 is corrected based on these detection results and determination results. A position control signal for controlling the movement of the truck 1 and a movement control signal for controlling the movement of the truck 1 are generated and supplied to the steering drive circuit 15. As a result, the steering drive circuit 15 outputs a drive signal to the steering mechanism (not shown) of the truck 1, and also outputs a speed control signal to the motor drive circuit (not shown), and as a result, the truck 1 corrects the movement position. Also, control of movement operations such as constant speed, deceleration, or stopping is performed.

As described above, according to the present embodiment: the guide mark 3 was imaged by the two-dimensional imager 10 with the moving direction of the cart 1 as the main scanning direction, and the image signal was integrated by the integrating circuit 11 for each main scanning line. By later converting it into a binary value and using it for detecting the guide mark 3, even if the guide mark 3 has defects such as dirt or peeling, the guide mark 3 can be detected with high precision without being affected by this. I can do it. Moreover, in the movement control circuit 14, the sampling binary signal D of each main scanning line is
Since the position and form of the guide mark 3 can be detected simply by determining the signal level of S, the time required for signal processing is significantly reduced compared to the case of performing conventional pattern recognition processing, thereby reducing the detection time. This makes it possible to increase the moving speed of the truck 1.・Furthermore, since complicated processing such as pattern recognition processing is not performed, the configuration and control of the movement control circuit 14 can be greatly simplified, and the integration circuit 11 and the second stage signal processing circuit are used as the preceding stage signal processing circuit. Since it is only necessary to provide the value converting circuit 12, it is possible to provide an apparatus with an extremely simple circuit configuration as a whole.

Note that the present invention is not limited to the above embodiments ((.

For example, in the embodiment described above, all main scanning sampling digitized signals for one screen are stored in the memory 13 and then read out and supplied to the movement control circuit 14. Each time a bit shift is input, the stored signal is input to the movement control circuit 14, thereby detecting the guide mark 3, and at the moment the guide mark 3 is detected, inputting the sampling binary signal i to the memory 13 is stopped. You can do it like this. In this way, the amount of information of the binary signal input to the memory 13 can be further reduced, and the processing speed can be improved accordingly. In addition, the configurations of the storage circuit, control circuit, two-dimensional imager, etc. can be modified in various ways without departing from the spirit of the present invention.

〔Effect of the invention〕

As described in detail above, according to the present invention, a two-dimensional imager is installed so that the main scanning direction is the same as the conveyance movement direction, and thereby an arbitrary area including the guide mark is imaged. The obtained imaging signal is integrated for each main scanning line, the integrated output is binarized, these binarized outputs are selectively stored in a storage circuit, and movement from these binarized outputs to the guide mark is performed. By calculating the positional deviation and controlling the movement position, the guide mark can be detected with high precision and at high speed without being affected by any defects in the guide mark. Moreover, it is possible to provide a conveying device that can realize this with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the external appearance of a conveyance device, FIGS. 2 and 3 are perspective views of essential parts for explaining different conventional conveyance devices, and FIG. 4 is a conveyance device according to an embodiment of the present invention. 5 and 6 are circuit block diagrams showing the configuration of the main parts of the device, and are for use in explaining the operation of the device.
The figure is a signal waveform diagram of each part of the device, and FIG. 6 is a schematic diagram showing guide marks for deceleration control and an image carrying range of a two-dimensional imager. DESCRIPTION OF SYMBOLS 1... Trolley, 2... Manipulator, 3... Guidance mark, 10... Two-dimensional imager, 11... Integrating circuit,
12... Binarization circuit, 13... Memory, 14...
Movement control circuit, 15... steering drive circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a conveyance device that detects a belt-shaped guide mark displayed on a conveyance path and moves along the guide mark while controlling the movement position according to the detection result, an arbitrary area including the guide mark is moved in the direction of movement. A two-dimensional imager captures an image in the main scanning direction, an integrating circuit that integrates the imaging signal obtained by this imager for each main scanning line, and an integral output obtained by this integrating circuit that divides the integral output according to a predetermined signal level. A binarization circuit that converts into values, a storage circuit that selectively stores the binarized signal for each main scan obtained by this binarization circuit, and 1. A conveying device comprising: a control circuit that calculates a displacement amount of a movement position with respect to a mark and controls the movement position so as to bring this displacement amount close to zero.