JPH046967B2 - - Google Patents

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 conveyance systems are used to transport products or parts between each process or to supply parts to each process. Attempts are being made to do this using 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 the guide mark 3 detecting means of such a device, a one-dimensional optical sensor 6 is conventionally used, for example, as shown in FIG. Therefore, as shown in L1 in the figure, there is a method that detects at regular intervals and detects the relative position of the guide mark 3 and the trolley 1 from these detected images to control the moving position of the trolley 1, or as shown in FIG. A two-dimensional imager 7 such as an industrial television camera (ITV camera) is used as a detector, and the two-dimensional imager 7 images an arbitrary area including the guide mark 3, and the guide mark 3 is patterned from the captured image. Detected by recognition method etc.
It is known that the positional deviation of the cart 1 with respect to the guide mark 3 is determined from this detection result and the moving position of the cart 1 is corrected.

[Problems with background technology]

However, each of these conventional devices has the following drawbacks. That is, in general, in this type of conveyance system, the width of the guide mark is partially narrowed or the mark is cut to recognize this as deceleration or stop information, but in such a case, the one-dimensional optical sensor 6 uses signal processing for each one-dimensional image individually to determine the position of the guide mark 3. Therefore, for example, if the guide mark 3 is partially dirty or peeled off, the deceleration Otherwise, it was often mistakenly recognized as stop information, resulting in low detection accuracy.

On the other hand, the one that uses the two-dimensional imager 7 performs pattern recognition for each imaging area to detect the position of the guide mark 3, so defects in the mark such as dirt or peeling are 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. I was unable to convert it into a 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 provides a conveying device that is capable of detecting guidance marks with high precision and high speed without being affected by defects in the guidance marks, and that can be realized with a simple configuration. The purpose is to provide.

[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 images an arbitrary area including the guide mark. The obtained imaging signal is integrated for each main scanning line, the integrated output is binarized, these binarized outputs are stored in a memory circuit, and the positional deviation of the movement position with respect to the guide mark is calculated from these binarized outputs. is calculated and the movement position is controlled.

[Embodiments of the invention]

FIG. 4 shows the 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 a guide mark 3 detector, and the main scanning direction of the two-dimensional imager 10 is aligned with the moving direction (arrow A) of the cart 1 as shown in the figure. It is installed in 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 11.
The integration circuit 11 integrates each main scanning line, and then the integrated output BS is sent to the binarization circuit 12.
The signal is binarized according to a predetermined signal level SL set in advance, and this binarized output CS is introduced into the memory 13. This memory 13 is composed of a serial input/parallel output type shift register having, for example, the number of bits for the main scanning line, and generates the binarized output signal CS from the binarization circuit 12 from a movement control circuit 14 to be described later. The sampling signal ES is sampled at the rear end of each main scan, and the sampling value DS is sequentially shifted and input. Movement control circuit 14
has a microprocessor as the main control unit, and outputs the sampling signal ES to the memory 13 at the rear end of each main scan, and also stores the sampling binary signal DS for one screen in the memory 13. When stored, these sampling binary signals DS are read out to detect the position of the guide mark 3 and determine the shape of the guide mark. Then, from the position detection results, calculate the shift amount of the movement position of the trolley 1 with respect to the guide mark 3,
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 the steering drive circuit 15 Output to.

With this configuration, while the trolley 1 is moving,
The guide mark 3 is imaged by a two-dimensional imager 10 with the moving direction of the cart 1 as the main scanning direction, and the image signal AS is integrated for each main scanning line by an integrating circuit 11 as shown in FIG. At this time, in the image pickup signal AS, the signal that images the guide mark 3 has a high level as shown by X in the figure, and the signal that has imaged the other parts has a low level as shown by Y. Therefore, the final level of the integral output BS is high when the imaged signal of the guide mark 3 is integrated, and is at a constant level when other parts are imaged. The integral output BS thus obtained is supplied to the binarization circuit 12 and binarized there. At this time, the binarization level
As shown in FIG. 5, SL is set so as to be able to detect all integral outputs of the imaging signal Y except for those obtained in areas other than the guide mark 3. Therefore, the image signal of the guide mark 3 can be reliably detected by the above-mentioned binarization, and even if there is a signal missing in the image signal due to dirt or peeling of the guide mark 3, for example, as shown in Z in FIG. However, 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. Therefore, the above-mentioned integration processing and binarization processing prevent erroneous detection due to a defect in the guide mark 3. Note that the regular guide mark for deceleration control has a cutout portion 3a that is set to be long enough to occupy approximately the entire imaging area as shown in FIG. 6, for example. The integrated output level of the imaged signal is approximately equal to the integrated output level of the signal obtained by imaging the portion other than the guide mark 3, and therefore, when binarized, it is detected that there is no guide mark. That is, even if the integral processing is performed, the regular deceleration control guide marks are reliably detected without any detection omissions.

The binarized signal CS 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 detects the position of the guide mark 3 in the image capture screen from the sampled binary signal DS as described above, determines the form of the guide mark 3, and uses these detection results and judgment results to A position control signal for correcting the moving position of the trolley 1 and a movement control signal for controlling the moving operation of the trolley 1 are generated and supplied to the steering drive circuit 15, respectively. As a result, the steering drive circuit 15 outputs a drive signal to the steering mechanism (not shown) of the bogie 1, and also outputs a speed control signal to the motor drive circuit (not shown), and as a result, the bogie 1
The movement position is corrected and movement operations such as constant speed, deceleration, or stop are controlled.

As described above, according to this embodiment, the guidance 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 is integrated by the integrating circuit 11 for each main scanning line. By later converting it into a binary value and using it to detect 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. be able to. Furthermore, the movement control circuit 14 can detect the position and form of the guide mark 3 by simply determining the signal level of the sampling binary signal DS of each main scanning line, so the signal The time required for processing is significantly shortened, thereby shortening the detection time and making it possible to increase the moving speed of the trolley 1. Further, 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 binarization circuit 12 are used as the preceding stage signal processing circuit. Since it is only necessary to provide this, it is possible to provide a device 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 binary 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 point in time when the guide mark 3 is detected, inputting the sampling binary signal 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 stored in a memory circuit, and the position of the movement position with respect to the guide mark is determined from these binarized outputs. By calculating the 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. It is possible to provide a conveyance device that can be realized with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the 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 in 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 used to explain the operation of the device. FIG. 5 is a signal waveform diagram of each part of the device, and FIG. FIG. 3 is a schematic diagram showing a guide mark and an imaging 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.

Claims (1)

[Claims] 1. 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 moving direction. a two-dimensional imager that 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 integrated output obtained by this integrating circuit to a predetermined signal level. Therefore, there is a binarization circuit that binarizes, a storage circuit that stores the binarized signal for each main scan obtained by this binarization circuit, and a binarization circuit that stores the binarized signal stored in this storage circuit. 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.