JP2009159528A - Detection sensor having cpu-mounted asic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection sensor capable of flexibly coping with custom-ordered products or various specification changes and capable of executing various required signal processing at high speed. <P>SOLUTION: A photoelectric sensor 1 has a light receiving circuit 5a which outputs an electric signal at a level corresponding to presence/absence of a detection target object 4, a detection circuit 7 which detects the presence/absence of the detection target object 4 based on the electric signal, and a display unit 8 which displays the detected presence/absence of the detection target object 4. The photoelectric sensor 1 further has a CPU 2a (central processing unit) which executes various operations and a CPU-mounted ASIC 2 (Application Specific Integrated Circuit) on which a logic circuit unit 2b which executes particular operations is integrally mounted. The CPU 2a executes display processing by the display unit 8, and the logic circuit unit 2b executes operations for the electric signal output from the light receiving circuit 5a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a detection sensor, and more particularly to a detection sensor including a CPU-mounted ASIC (CPU: central processing unit, ASIC: application specific integrated circuit).

  Conventionally, as signal processing in a detection sensor such as a photoelectric sensor, detection processing for detecting a state such as the presence or absence of an object to be detected 4 such as a workpiece, display processing for displaying the detection result or the like on a predetermined display unit, and the like. is there.

In this type of photoelectric sensor, a technique is known in which the above-described detection process and display process are performed by a single CPU (control unit) (see, for example, Patent Document 1).
JP 2000-22514 A

  However, when a plurality of signal processes are executed by a single CPU (microcomputer) in this way, each signal process inevitably becomes a sequential process. In other words, for example, the display process is executed after the detection process is completed, and the detection process is executed after the display process is completed. Therefore, it is difficult to realize a high speed detection process. In this case, although the speed of each signal processing is improved to some extent by improving the performance of the CPU, there are disadvantages such as an increase in power consumption accompanying an increase in the clock frequency and an increase in the unit price of the CPU.

  In recent years, detection sensors such as photoelectric sensors have become increasingly demanding to increase the speed of display processing because the display processing has become complicated with the increase in the number of display functions.

  On the other hand, a method of speeding up the above-described display processing using a full logic circuit (full logic ASIC) and performing each signal processing at high speed is also conceivable. Formation of a simple logic circuit (change of all layers of the photomask pattern) is required, and it is not possible to flexibly cope with a change in display function specification in a custom-made product or the like.

  The present invention has been made to solve the above-described problems, and its object is to detect a custom-made product and various specification changes flexibly, and to perform various required signal processing at high speed. Is to provide.

  In order to solve the above problems, the invention according to claim 1 is characterized in that an output means for outputting an electric signal of a level corresponding to the state of the object to be detected, and the state of the object to be detected based on the electric signal. A detection sensor comprising a detection means for detecting and a display means for displaying at least the state of the detected object, a CPU (central processing unit) for executing various arithmetic processes, and a specific calculation A CPU-mounted ASIC (integrated circuit for a specific application) that is integrally mounted with a logic circuit unit that executes processing is further provided. The CPU causes the display unit to execute display processing, and the logic circuit unit includes The gist of the present invention is that the detection process of the state of the object to be detected is performed by the detection means.

  According to this configuration, the display process for displaying the state of the detected object on the display means is executed by the CPU of the CPU-equipped ASIC, and the calculation process of the electric signal output from the output means, that is, the detected object This detection process is executed by the logic circuit unit of the CPU-mounted ASIC. As a result, the detection process of the detection object and the display process for displaying the state of the detection object on the display means can be executed in parallel, and the detection process is not affected by the time required for the display process. The detection process of the detected object can be continuously executed. In addition, with the increase in the number of display functions, even if the frequency and type of display processing for displaying various information and functions on the display means increase, the CPU does not change the logic circuit (changes the photomask). It becomes possible to respond flexibly by changing the software used.

  According to a second aspect of the present invention, in the detection sensor according to the first aspect, the detection sensor further includes an operation unit that performs a setting operation of various information used for control of the detection sensor, and the CPU includes The gist is that arithmetic processing of various information set by the operation means is executed.

  According to this configuration, since the arithmetic processing of various information set by the operating means is executed by the CPU of the CPU-equipped ASIC, the arithmetic processing can be flexibly handled by changing the software used in the CPU.

  According to a third aspect of the present invention, in the detection sensor according to the first or second aspect, the detection sensor further includes a communication unit used for communication with the outside, and the logic circuit unit includes the communication. The gist of the present invention is that an electric signal calculation process is performed.

  According to this configuration, since the arithmetic processing of the electrical signal for performing communication with the outside is executed by the logic circuit unit of the CPU-equipped ASIC, the arithmetic processing can be executed at high speed by the logic circuit unit in hardware. It becomes like this.

  ADVANTAGE OF THE INVENTION According to this invention, the detection sensor which can respond flexibly to a custom-made product and various specification changes, and can perform the various signal processing requested | required at high speed can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
As shown in FIG. 1, in this embodiment, the photoelectric sensor 1 as a detection sensor is a so-called reflection type photoelectric sensor, and irradiates light to a detected object 4 such as a workpiece conveyed by a conveyor of a production line. And a light receiving means 5 for receiving the light incident on and reflected by the detected object 4, and a CPU-mounted ASIC 2 (CPU: CPU) as a control means for controlling the operations of the light projecting means 3 and the light receiving means 5. A central processing unit, ASIC (application specific integrated circuit).

  The light projecting means 3 is a light projecting circuit 3a and a light projecting element that is electrically connected to the light projecting circuit 3a, converts an electric signal output from the light projecting circuit 3a into light, and emits the light. 3b and a light projecting lens 3c that adjusts the optical path of the light emitted from the light projecting element 3b and irradiates the detected object 4 with the light projecting lens 3c.

  The light receiving means 5 is a light receiving element 5b that converts input light into a predetermined electric signal, and a light receiving device that guides the light emitted from the light projecting element 3b and reflected by the detected object 4 to the light receiving element 5b. A lens 5c and a light receiving circuit 5a electrically connected to the light receiving element 5b and to which the electric signal is input from the light receiving element 5b. In the present embodiment, the light receiving circuit 5a constitutes an output means. In the light receiving circuit 5a, a predetermined amplification factor is set so that the input electric signal has a level corresponding to the presence or absence of the detected object 4. Is amplified and output.

  A driving circuit 6 for driving the light projecting circuit 3a is connected to the light projecting circuit 3a, and the light projecting circuit 3a is configured based on a control signal output from the drive circuit 6. An electric signal is output to the light projecting element 3b to adjust the light projection amount and the emission timing of the light emitted from the light projecting element 3b. The drive circuit 6 is also a constituent element of the photoelectric sensor 1 of the present embodiment.

  Connected to the light receiving circuit 5a is a detection circuit 7 as a detecting means for detecting the state of the detected object 4 whose reflected light is received by the light receiving element 5b. Specifically, in the detection circuit 7, the level (light reception amount) of the electric signal output from the light receiving circuit 5 a when the detected object 4 does not exist in a predetermined detection area, and the detected object 4 A threshold value is set based on the level (light reception amount) of the electrical signal output from the light receiving circuit 5a when present in the detection area and setting information (determination condition) described later. Then, the threshold value and the level (light receiving amount) of the electric signal at that time are compared using a comparator, the presence or absence of the detection object 4 is determined based on the comparison result, and the determination result is a detection signal (electric signal). ) Is output.

  The CPU-mounted ASIC 2 is integrally mounted with a CPU 2a that executes various arithmetic processes and a logic circuit unit 2b that executes specific arithmetic processes. The CPU 2a stores (stores) various control programs and includes a memory 2c for storing various data necessary for the control programs.

  The CPU 2a is connected to the drive circuit 6 so as to be controllable by a control signal output from the CPU 2a, and the detection circuit 7 is connected to be able to output the detection signal (electric signal). ing. The detection circuit 7 is connected to the drive circuit 6 so as to be controllable by the CPU 2a via the drive circuit 6.

  Further, the CPU 2a includes an operation unit 8 as an operation unit for performing setting operation or setting operation of setting information (function) such as a determination condition related to determination of the presence or absence of the detection object 4 by the detection circuit 7, As display means for displaying the presence / absence of the detection object 4 detected by the detection circuit 7 (the state of the detection object 4) and the setting information set or changed via the operation unit 8 using an LED or the like. The display unit 9 is connected. Specifically, the setting information is grouped into a hierarchical structure of three layers, an upper layer (upper layer), a middle layer (middle layer), and a lower layer (lower layer). In response to the operation (switching operation), the setting information of each layer is switched and displayed on the display unit 9 and can be changed. Basic setting information with high versatility is classified into the upper layer, which is the highest layer, and advanced setting information is classified into the lower layer, which is the lowest layer.

  Further, the CPU 2a includes a communication light projecting element 21a and a communication light receiving element 22a as communication means capable of communicating with the external communication apparatus 101 and the external communication apparatus 102 by light (optical communication). And a receiving circuit 22. The communication light projecting element 21a and the communication light receiving element 22a are also constituent elements of the photoelectric sensor 1 of the present embodiment.

  In the present embodiment, the photoelectric sensors 1 are collectively controlled by an external control unit, and can communicate with each other so that the setting information having the hierarchical structure is sequentially displayed on the display unit 9 for each hierarchy. In the state, it is adjacent to another photoelectric sensor 1. A sensor system is configured by the plurality of photoelectric sensors 1,... Arranged adjacent to each other and the control unit.

  Each of the photoelectric sensors 1 uses the communication light projecting element 21a and the communication light receiving element 22a, and uses the external communication device 101 and the external communication device 102 (the communication light projecting element 21a of the control unit or other photoelectric sensor 1). Optical communication is performed with the communication light receiving element 22a). That is, the receiving circuit 22 converts an optical signal (pulse optical signal or the like) transmitted from the external communication device 102 and received via the communication light receiving element 22a into an electric signal (digital signal) and inputs it to the CPU 2a. To do. The transmission circuit 21 converts an electrical signal (digital signal) output from the CPU 2a into an optical signal, and transmits the optical signal to the external communication device 101 via the communication light projecting element 21a.

  In the present embodiment, the CPU 2a is various information set or changed by the operation unit 8 to be used for controlling the photoelectric sensor 1 based on the control program, and is to be detected by the detection circuit 7. In addition to executing calculation processing of setting information such as determination conditions relating to the determination of the presence / absence of 4, display processing for displaying the setting information and the presence / absence of the detected object 4 on the display unit 9 is executed. As described above, the CPU 2a of this embodiment functions as a display control unit of the display unit 9 and a setting control unit of the operation unit 8.

  On the other hand, in the present embodiment, the detection circuit 7, the transmission circuit 21, and the reception circuit 22 are formed in the logic circuit unit 2b. Then, the logic circuit unit 2b uses a logic circuit designed to execute a specific calculation process to detect the state of the detected object 4 (determination of the presence or absence of the detected object 4 in the detection circuit 7). Logic processing for electrical signals) and electrical signal computation processing for communication with the external communication devices 101 and 102 (logic conversion between optical signals and electrical signals in the transmission circuit 21 and the reception circuit 22) Are configured to be executed in parallel by parallel arithmetic processing.

The photoelectric sensor 1 (a plurality of photoelectric sensors 1,...) Of the present embodiment is configured as described above and operates as follows.
That is, as shown in FIG. 1, in each photoelectric sensor 1, a control signal is output from the driving circuit 6, and in the light projecting means 3, the light projecting circuit 3a is operated, and a predetermined light projecting amount from the light projecting element 3b. E light is emitted toward the detection object 4 at a predetermined emission timing. The light irradiated to the detected object 4 is reflected by the detected object 4 and received by the light receiving element 5 b of the light receiving means 5. And it is converted into an electric signal in the light receiving element 5b.

  This electric signal is further input to the light receiving circuit 5a, amplified to an electric signal of a level corresponding to the presence or absence of the detected object 4, and input to the detection circuit 7 formed in the logic circuit portion 2b. In the detection circuit 7, an electric signal logic calculation process for determining the presence or absence of the detected object 4 is performed. That is, the level of the input electric signal (light reception amount) is compared with the threshold value, and if it is equal to or higher than the threshold value, it is determined that the detected object 4 is present. It is determined that there is no detected object 4. Further, the determination result is output as a detection signal to the CPU 2a, and the presence or absence of the detected object 4 is displayed on the display unit 9 of each photoelectric sensor 1 through the display process by the control program in the CPU 2a. Furthermore, on the display unit 9 of each photoelectric sensor 1, setting information having a hierarchical structure transmitted from the other photoelectric sensor 1 is changed from an optical signal in the receiving circuit 22 formed in the logic circuit unit 2b to an electrical signal. After being subjected to the logic conversion process and the display process by the control program, they are displayed in order on the display unit 9 for each layer.

According to the photoelectric sensor 1 of the present embodiment, the following actions and effects can be obtained.
(1) A calculation process of setting information such as a determination condition relating to the determination of the presence / absence of the detected object 4, a display process for displaying the setting information on the display unit 9, and a display process for displaying the presence / absence of the detected object 4 It is executed by the CPU 2a (control program) mounted on the CPU-mounted ASIC 2, and also performs detection processing of the detected object 4 and calculation processing of electrical signals for communication with the external communication devices 101 and 102 (hereinafter referred to as “communication”). Process ") is executed by parallel logic processing by the logic circuit 2b of the CPU-mounted ASIC 2. As a result, the detection process of the detected object 4, the communication process, and the display process for displaying various information and functions on the display unit 9 can be executed in parallel, which depends on the time required for the display process and the communication process. Therefore, the detection process of the detection object 4 can be continuously executed. In addition, the logic circuit unit 2b can perform high-speed processing in hardware using a logic circuit designed to execute specific arithmetic processing, so that the detection processing of the detected object 4 can be further accelerated. Can also respond.

  (2) With the increase in the number of display functions, even if the frequency and type of display processing for displaying various types of information and various functions on the display unit 9 increase, formation of a new logic circuit (change of all layers of the photomask pattern) ), It is possible to flexibly cope with the change of the control program of the CPU 2a.

  (3) Since the arithmetic processing of various information set by the operation unit 8 is executed by the CPU 2a of the CPU-equipped ASIC 2, the arithmetic processing can be flexibly handled by changing the control program used by the CPU 2a.

  (4) Since arithmetic processing of electric signals for performing communication with the external communication devices 101 and 102 is executed by the logic circuit unit 2b of the CPU-mounted ASIC 2, the arithmetic processing is performed by the logic circuit unit 2b in hardware. It can be executed at high speed.

The above embodiment may be modified as follows.
In the above-described embodiment, the photoelectric sensors 1 can communicate with each other so that the setting information having the hierarchical structure is displayed on the display unit 9 one by one for each hierarchy in a batch control by an external control unit. In the state, the sensor system was constituted by the other photoelectric sensors 1 and the plurality of photoelectric sensors 1,... However, the technical idea of the present invention is not limited to this, and as shown in FIG. 2, a CPU 12a that is configured independently and executes various arithmetic processes and a logic circuit unit 12b that executes specific arithmetic processes are integrated. The CPU 12a includes a memory 12c for storing (storing) a control program and various data necessary for the control program. The CPU 12a is detected by the detection circuit 7. The photoelectric sensor 10 to which the display unit 9 for displaying the presence or absence of the detected object 4 is connected (the light projecting means 3, the light receiving means 5, the drive circuit 6, and the detection circuit 7 are the same as the photoelectric sensor 1 of the above embodiment. It is also possible to apply to the above.

  In the above embodiment, the operation unit 8 for setting or changing the setting information (function) such as the determination condition related to the determination of the presence / absence of the detected object 4 by the detection circuit 7 is connected to the CPU 2a, and the CPU 2a ( The calculation process of the setting information set or changed (input) by the operation unit 8 is executed by the control program. However, the technical idea of the present invention is not limited to this, and as shown in FIG. 2, a CPU that integrally includes a CPU 12 a that executes various arithmetic processes and a logic circuit unit 12 b that executes specific arithmetic processes. In addition to the on-board ASIC 12, the CPU 12 a is connected to an operation unit 8 for setting or changing setting information (function) such as determination conditions related to determination of the presence / absence of the detection object 4 by the detection circuit 7. And a photoelectric sensor 10 (light projecting means 3, light receiving means 5, drive circuit 6 and detection circuit) connected to a display unit 9 for displaying the presence or absence of the detected object 4 detected by the detection circuit 7. The circuit 7 is configured similarly to the photoelectric sensor 1 of the above embodiment.

  In the case of the photoelectric sensor 10 configured as described above, as in the photoelectric sensor 1 shown in FIG. 1, the detection process of the detection object 4 and the display process for displaying various information on the display unit 9 are respectively performed by the CPU-mounted ASIC 2. The logic circuit unit 2b and the CPU 2a (control program) can execute them in parallel. Thereby, the detection process of the detection object 4 can be continuously executed without being influenced by the time required for the display process. In addition, the logic circuit unit 2b can perform high-speed processing in hardware using a logic circuit designed to execute specific arithmetic processing, so that the detection processing of the detected object 4 can be further accelerated. Can also respond.

  In the above embodiment, the technical idea of the present invention is embodied in the reflective photoelectric sensor 1, but is not limited thereto, and is embodied in other detection sensors such as a transmission photoelectric sensor, a fiber sensor, and a laser sensor. May be used.

1 is a circuit block diagram showing an electrical configuration of a photoelectric sensor according to an embodiment of the present invention. The circuit block diagram which shows the electric constitution of the photoelectric sensor which concerns on the modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,10 ... Photoelectric sensor (detection sensor), 2,12 ... CPU mounting ASIC, 2a, 12a ... CPU, 2b, 12b ... Logic circuit part, 3 ... Light projecting means, 4 ... Detected object, 5 ... Light receiving means.

Claims (3)

An output means for outputting an electric signal at a level corresponding to the state of the detected object, a detecting means for detecting the state of the detected object based on the electric signal, and at least the detected state of the detected object is displayed. A detection sensor comprising display means for
A CPU-equipped ASIC (integrated circuit for specific applications) that integrally mounts a CPU (central processing unit) that executes various types of arithmetic processing and a logic circuit unit that executes specific arithmetic processing,
The CPU is caused to execute display processing by the display means,
A detection sensor, wherein the logic circuit unit is caused to execute a detection process of the state of the detection object by the detection means. The detection sensor according to claim 1,
The detection sensor further includes operation means for performing an operation for setting various information used for control of the detection sensor,
A detection sensor characterized in that the CPU is caused to execute arithmetic processing of various information set by the operation means. In the detection sensor according to claim 1 or 2,
The detection sensor further includes communication means used for communication with the outside,
A detection sensor, wherein the logic circuit unit is configured to execute a calculation process of an electric signal for performing the communication.

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