JP2003346272A - Sensor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor system capable of reducing the influence by the failure of a sensor, while reducing a signal transmitting time, and to set an address. <P>SOLUTION: A relay 16 is mounted between a terminal metal 11 and a terminal metal 12 of sensors 1, and the relay 16 is opened and closed on the basis of a signal from a CPU 15. The CPU 15 opens the relay 16 when it receives an address setting mode signal from a master unit 2, and closes the relay 16 when it receives a control communication mode signal. Whereby the address setting signal is successively transmitted to each sensor 1 by a bucket relay method, when the address is set, and each sensor 1 can be directly communicatable to the master unit 2 by bus connection when the control communication is performed. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a sensor system.

[0002]

2. Description of the Related Art An example of a sensor system including a plurality of optical fiber sensors is disclosed in Japanese Patent Application Laid-Open No. 2001-222788. This is because, by arranging each sensor unit adjacent to each other, the light emitting element and the light receiving element provided on the side of each sensor unit are opposed to the light emitting element and the light receiving element of the adjacent sensor unit, and further, The master unit is arranged next to the sensor unit located at one end of the sensor units arranged adjacent to each other, and the light receiving element and the light projecting element are opposed to each other. According to this, the signal from the master unit is transmitted to each sensor unit by a so-called relay method in which the signal from the master unit is sequentially transmitted to each sensor unit via the light emitting element and the light receiving element, and the signal from each sensor unit is transmitted to another sensor unit. Is returned to the master unit via the sensor unit.

As an advantage of this sensor system, since signals are transmitted by a relay method, it is possible to automatically set the address of each sensor unit. For example, when the number of sensor units is changed, the address of each sensor unit must be changed accordingly. For example, when a signal indicating an address number is transmitted from the master unit to the sensor unit, the sensor unit receiving this signal adds 1 to the number, sets this as its own address, and transmits it to the next sensor unit. I do. Thereafter, the address setting is sequentially performed in each sensor unit.

[0004] However, when the number of sensor units is increased, the longer the sensor unit is away from the master unit, the longer the signal transmission time is, and the control from the master unit may be delayed and the sensor unit may not operate reliably. . For example, in the case where the master unit monitors the received light amount of each sensor unit and transmits a signal to reset the threshold to the sensor system on condition that the received light amount has decreased to a predetermined value or less, Until the signal is transmitted, the operation of the sensor unit becomes unstable, and the possibility of erroneous detection increases. Therefore, it is desired to shorten the signal transmission time as much as possible. Also, if any sensor unit cannot transmit or receive a signal due to a failure or the like, the signal will not reach the sensor unit that is away from the sensor unit to the master unit, and it will be impossible to control the sensor unit. It is also a concern.

[0005]

Therefore, it is conceivable to connect each sensor unit to the master unit by a bus. As a result, the signal is transmitted from the master unit to each sensor unit simultaneously, so that the signal transmission time can be reduced. In addition, each sensor unit directly transmits and receives signals to and from the master unit without interpreting the other sensor units. There is also an advantage that the sensor unit is not affected.

However, in the above-mentioned sensor system, when the address of each sensor unit is automatically changed by the master unit, if the signal indicating the address number is transmitted from the master unit to each sensor unit, the sensor unit sequentially changes the address. However, in the bus connection, since each sensor unit receives the signal at the same time, there is a disadvantage that the address is not set correctly.

The present invention has been completed on the basis of the above-described circumstances, and a sensor capable of shortening a signal transmission time while reliably controlling a sensor unit and automatically setting an address. The purpose is to provide a system.

[0008]

According to a first aspect of the present invention, a master unit includes a plurality of sensor units each having a transmitting unit and a receiving unit, and the receiving unit of one sensor unit and its sensor are provided. The transmitting unit of the sensor unit adjacent to one side of the unit, and the transmitting unit of the one sensor unit and the receiving unit of the sensor unit adjacent to the sensor unit located on the one side are opposite to the transmission path. In a sensor system in which the master unit is connected to the receiving unit of the sensor unit on one end side of the plurality of sensor units via the transmission path, the master unit is connected to the master unit via the transmission path. An address setting mode for setting addresses of the plurality of sensor units and control of the plurality of sensor units are performed. Switching means for switching between a control communication mode, a mode signal transmitting means for transmitting an address setting mode signal in the address setting mode, and transmitting a control communication mode signal in the control communication mode, and a sensor unit to be controlled. Input means for inputting the associated control content, and, when the address setting mode is set by the switching means, after the address setting mode signal is transmitted from the mode signal transmitting means, the setting as the basis of the address setting Address setting control means for transmitting an address setting signal including information; and when the control communication mode is set by the switching means, the control signal is input to the input means after the control communication mode signal is transmitted from the mode signal transmitting means. Attached to the sensor unit to be controlled. Address numbers and control signal transmitting means for transmitting a control signal comprising a control content is provided, the said sensor unit, provided between the input portion of the output section and said receiving means of said transmitting means,
Allowing transmission of signals between the input and the output,
Or, the switch means for inhibiting, when the address setting mode signal is received, the switch means is controlled to inhibit the transmission of the signal between the input unit and the output unit, and the control communication mode signal is received. Sometimes switch control means for controlling the switch means to allow transmission of a signal between the input section and the output section, and when the address setting signal is received following the address setting mode signal, the address The address setting unit sets its own address number in accordance with a predetermined procedure based on the setting information included in the setting signal, updates the setting information, and includes the updated setting information in the address setting signal to be transmitted from the transmitting unit. Executing means, when the control signal is received following the control communication mode signal, the control signal is included in the control signal. It compares the address number and its own address number on condition that they are the same, having characterized in that the control execution means for executing the control content of the control signal is provided.

According to a second aspect of the present invention, in the first aspect, the output section of the transmitting section is constituted by a light emitting element, and the input section of the receiving section is constituted by a light receiving element. Is constituted by an optical fiber, and the switch means is constituted by a liquid crystal shutter.

[0010]

<Operation and Effect of the Invention><Invention of claim 1> When an address setting mode signal is transmitted from the master unit and the switch control means of each sensor unit receives this signal,
This controls the switch means to inhibit signal transmission between the input and output. As a result, each sensor unit transmits signals from the master unit to the other sensor units in a so-called relay system, in which signals are transmitted between the sensor units. Therefore, address setting is performed in order by each sensor unit. It is. On the other hand, when the control communication mode signal is transmitted from the master unit and the switch control means of each sensor unit receives this signal, it controls the switch means to allow the signal transmission between the input unit and the output unit. . As a result, since each sensor unit is bus-connected to the master unit, a signal transmitted from the master unit is directly sent to each sensor unit.
And received simultaneously. As a result, it is possible to minimize the influence of the failure of the sensor system while greatly reducing the signal transmission time, and it is possible to automatically perform the address setting.

<Invention of Claim 2> Since the signal is transmitted by an optical signal, there is no influence by electric noise.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> One embodiment of a sensor system according to the present invention will be described with reference to FIGS. The sensor system of the present embodiment has four optical fiber sensors 1 (hereinafter, referred to as sensor 1) having the same structure.
Called. ) And a master unit 2 for controlling these optical fiber sensors 1. The sensors 1 are arranged adjacent to each other, and a master unit 2 is arranged next to the sensor 1 at one end of the sensors 1.
In particular, when any one of the sensors 1 is designated, FIG.
Are referred to as the first sensor 1, the second sensor 1, the third sensor 1, and the fourth sensor 1 from the left.

A terminal fitting 11 is provided on one side of each sensor 1.
A male connector having an output unit (corresponding to the claim) and a female connector having a terminal fitting 12 (corresponding to the input unit) are provided.
Reference numeral 2 denotes a terminal fitting 11 or a terminal fitting of an adjacent sensor 1 via a transmission cable 3 (corresponding to a transmission path described in the claims) having male and female connectors at both ends to be fitted to both connectors. 12 are electrically connected. That is, the terminal fitting 11 of one sensor 1 is connected to the terminal fitting 12 of the sensor 1 on the right side in the figure via the transmission cable 3, and the terminal fitting 12 is connected on the left side via the transmission cable 3. It is connected to the terminal fittings 11 of the sensor 1 and is connected sequentially as a whole. A male connector having a terminal fitting 21 is also provided on one side surface of the master unit 2, and is connected to the terminal fitting 12 of the female connector of the first sensor 1 via the transmission cable 3.

Hereinafter, the electrical configuration of the sensor system will be described. The housing of the master unit 2 has a changeover switch 22 (corresponding to a switching means described in the claims), an operation unit 23 (corresponding to the input means described in the claims), a display unit 2
4 are provided. The changeover switch 22 can be switched between the “address setting” side and the “control communication” side, and this switching state is taken into the CPU 25. The operation unit 24 sets a control command for the sensor 1, and sets an address number set for the sensor 1 to be controlled and a control command for the sensor 1, and performs a determination operation to determine the address. The settings are loaded into the CPU 25. The display unit 24 displays information from the CPU 25. Further, the CPU 25 is connected with a transmitting unit 26 for transmitting a signal from the CPU 25 to the transmission cable 3 and a receiving unit 27 for passing a signal from the transmission cable 3 to the CPU 25. The transmitting unit 26 and the receiving unit 27 It is connected to the terminal fitting 21.

Here, when the changeover switch 22 is switched to the “address setting” side, the CPU 25 switches to the address setting mode, outputs an address setting mode signal to the transmitting unit 26, and transmits this signal to the transmission cable 3 from the transmitting unit 26. Is sent. Thereafter, an address setting signal including a predetermined address number (corresponding to the setting information described in the claims) is transmitted. On the other hand, when switching to the “control communication” side, C
The PU 25 switches to the control communication mode, transmits a control communication mode signal to the transmission unit 26, and the transmission unit 26 transmits this signal to each sensor 1. Thereafter, a control signal including an address number set by the operation unit 23 and a control command indicating control contents is output. Therefore, the CPU 25 and the transmission unit 26 may include:
It functions as address setting control means and control signal transmission means.

A transmitting portion 13 (corresponding to the transmitting means in the claims) is provided on the terminal fitting 11 of the male connector of the sensor 1.
Is connected to the terminal fitting 12 of the female connector.
4 (corresponding to the receiving means described in the claims), and the transmitting unit 13 and the receiving unit 14 are connected to the CPU 15. A relay 16 is provided between the terminal fittings 11 and 12.
(Corresponding to a switch means described in the claims), and the relay 16 is opened and closed based on a signal from the CPU 15.

When the CPU 15 receives the address setting mode signal via the receiving unit 14 (No in step S1 and Yes in step S7), the relay 16 is opened on condition that a predetermined time has elapsed. Thereafter, when the address setting signal is received (Yes in step S8), the address number "N" included in the address setting signal is read (step S9), and "1" is added to the address number "N". (Step S10) “N + 1” is set as its own address (Step S11). Then, the address number “N” is updated to “N + 1”, and this is
3 to the second sensor 1 (step S1).
2). When each sensor 1 receives the control communication mode signal (Yes in step S1), the relay 16 is closed after transmitting this signal to the second sensor 1. Then, upon receiving the control signal (Yes in step S2), if the address number included in this signal matches its own address number (Yes in step S3), the control command is read and the operation corresponding to the control command is performed. After that, a response signal is transmitted (steps S4, S5, S6) (see FIG. 3). Further, the CPU 15 is connected to the light projecting unit 17 and the light receiving unit 18, and the CPU 15 is connected to the detection area via the light projecting optical fiber from the light projecting unit 16, for example, during periods other than when the above operation is performed. And the light from the detection area is received by the light receiving unit 17 through the optical fiber for light reception, and the presence or absence of the detected object in the detection area is determined based on the amount of received light and a threshold value set inside. The light emitting and receiving operation is performed. Hereinafter, the second, third, and fourth sensors 1 have the same configuration as the first sensor 1. The CPU 15 also functions as a switch control unit, an address setting execution unit, and a control execution unit described in the claims.

The CPU 25 of the master unit 2 is provided with a response period for receiving a response from each sensor 1 after transmitting a control signal. Specifically, after the control signal is transmitted, the signal received by the receiving unit 27 at predetermined intervals is validated.
First, the signal received by the receiving unit 27 during the first activation period is regarded as a response from the sensor 1 having the smallest address number, and the signal received by the receiving unit 27 during the second activation period is regarded as 2. This is regarded as a response from the sensor 1 having the lowest address number. In addition, the sensors 1 of other address numbers are sequentially waited for a response. In each sensor 1, a period for transmitting a response signal to the master unit 2 is defined, and the response signal is transmitted when a specific predetermined period has elapsed since the control signal was received. That is, the sensor 1 having the lowest address number transmits a signal within the first activation period of the master unit 2, and the sensor 1 having the second lowest address number transmits a signal within the second activation period. Send. The signals of the sensors 1 having other address numbers are sequentially returned in synchronization with the activation period of the master unit 2.

Hereinafter, the operation of the sensor system according to the above configuration will be described. <Address setting> First, to set the address of each sensor 1, the changeover switch 22 of the master unit 2 is switched to the "address setting" side. Then, each sensor 1 receives the address setting mode signal. Then, the relays 16 of all the sensors 1 are opened, and each sensor 1 is connected to the master unit 2.
(See FIG. 1). Then, after a predetermined time has passed, the master unit 2 sends the address number “0”.
Is transmitted and received by the first sensor 1. The other sensors 1 are in a standby state until receiving the address setting signal. The first sensor 1 reads the address number “0”, sets the number “1” obtained by adding 1 to the address number as its own address number, updates the address number “0” to “1”, and updates the second sensor 1 After sending to
This address number "1" is displayed on a display unit (not shown). The second sensor 1 to the fourth sensor 1 have their own address numbers set in the same procedure, and the numbers are displayed on the display unit. That is, “2” is displayed on the second sensor 1, “3” is displayed on the third sensor 1, and “4” is displayed on the display unit 4. When the number of sensors 1 is changed after the address is set, the address can be set for each sensor 1 by performing the above-described address setting again.

<Control communication> If, for example, it is desired to know the amount of light received by the light receiving sections of the second sensor 1 and the third sensor 1, first, the changeover switch 22 is set to "control communication".
Switch to the side. Then, a control communication mode signal is sent from the master unit 2 to the first sensor 1. Upon receiving this signal, the first sensor 1 closes the relay 16. Thereafter, the second sensor 1 to the fourth sensor 1 also receive this signal sequentially and close the relay 16, whereby each sensor 1 is connected to the master unit by a bus (see FIG. 2). After this, master unit 2
When the operation unit 23 is operated to set the address number “2” of the second sensor 1, the address number “3” of the third sensor 1, and the command for returning the amount of received light, the address numbers “2” and “3” are received. The command of the quantity reply is transmitted as a control signal, and all the sensors 1 receive this control signal simultaneously. At this time, in the first sensor 1 and the fourth sensor 1, since the address numbers included in the control signal are “2” and “3”,
Judge that the address is not its own address number and do not execute the control instruction. Since the second sensor 1 and the third sensor 1 match their own address numbers, the master unit receives the received light amount as a response signal after a lapse of a predetermined time after receiving this control signal according to the received light amount return command. 2
Send to Then, these response signals are received by the master unit 2 and the amount of received light is displayed on the display unit 24.

The operator checks the light receiving amounts of the second and third sensors 1 displayed on the display unit. Here, the third sensor 1
If it is determined that the light receiving amount of the image data has decreased, the operation unit is operated to set the address number “3” and the instruction of resetting the threshold value, and then perform the determination operation. Then, the third sensor 1 receiving the control signal transmitted from the master unit 2 resets the threshold.

According to the sensor system of the present embodiment, when setting an address, each sensor 1 performs signal transmission by a relay system in which a signal from the master unit 2 is sequentially passed to an adjacent sensor 1. The address setting of each sensor 1 can be performed automatically. When performing control communication, each sensor 1 is connected to the master unit 2.
Are connected to a bus and signal transmission is performed directly with master unit 2. This allows each sensor 1 to receive the control signal directly and simultaneously from the master unit 2, so that the signal transmission time is shortened and the control failure of another sensor 1 due to the failure of the sensor 1 is avoided.

<Second Embodiment> A second embodiment of the sensor system according to the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, the signal is transmitted between the sensors 1 using light as a signal transmission medium. In the sensor 1, the light projecting element 41 (output unit) for projecting light, the light projecting element 41
Light transmitting circuit 42 (which constitutes transmitting means), a light receiving element 43 (input unit) for receiving light, and a light receiving circuit 44 for receiving a signal from the light receiving element 43
(A receiving means is constituted by both 43 and 44), an optical fiber 5 (transmission path) and a liquid crystal shutter 45 (switch means). In the master unit 2, a light emitting element 61, a light emitting circuit 62, a light receiving element 63 and a light receiving circuit 64. Here, the light emitting element 41 and the light receiving element 43 of the adjacent sensor 1
Are connected via the optical fiber 5, and the light projecting element 61 of the master unit 2 is connected to the light receiving element 43 of the first sensor 1 via the optical fiber 5. CPU2
5. The light projecting element 61 and the light projecting circuit 62 function as a mode signal transmitting means, an address setting control means, and a control signal transmitting means.

The two open ends of the optical fiber 5 are respectively inserted into fiber insertion holes provided in the housing of the sensor 1 so that light from the light emitting element of the sensor 1 is received by the light receiving element 43 of the adjacent sensor 1. It is designed to receive light. Similarly, a fiber insertion hole is also provided in the master unit 2, and light from the light projecting element 61 is transmitted through the optical fiber 5 to the first sensor 1.
Are guided to the light receiving element 43. Further, an optical fiber 5 having a liquid crystal shutter 45 interposed therebetween is provided in the center of each sensor 1, and one opening end of the optical fiber 5 can mutually enter and exit with the opening end of the optical fiber 5 and the light receiving element 43. The other opening end face is also arranged so that light can enter and exit with the opening end of the optical fiber 5 and the light projecting element 41 mutually.

When an address setting mode signal is transmitted from the CPU 25 and the CPU 15 of each sensor 1 receives this signal, the application of the voltage to the liquid crystal shutter 45 is stopped after a lapse of a predetermined time to inhibit the transmission of light. Thereby, as shown in FIG. 5, each sensor 1 is equivalent to a configuration in which a signal is transmitted by a so-called relay method in which a signal from the master unit 2 is sequentially passed to an adjacent sensor 1. On the other hand, when the control communication mode signal is transmitted and received by the CPU 15 of each sensor 1, this signal is transmitted to the adjacent sensor 1, and a voltage is applied to the liquid crystal shutter 45 to allow the passage of light. Thereby, as shown in FIG. 6, each sensor 1 is equivalent to a configuration in which the sensor unit 1 is connected to the master unit 2 via a bus.

According to the present embodiment, since light is used as a signal transmission medium, there is no influence by electric noise.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition, various changes can be made without departing from the scope of the invention. (1) In the first embodiment, the relay 16 which is a mechanical switch is used as the switch means.
An electric switch such as an ET or a bipolar transistor may be used. (2) In the above embodiment, the control command for each sensor is not limited to the received light amount return, and may be, for example, a command for switching the mode of the light emitting / receiving operation or setting a timer. (3) Further, the sensor system is not limited to the configuration of the four sensors 1, but may be configured of, for example, five or more or three or less sensors 1. (4) In the above embodiment, when the address of each sensor 1 is set, a number obtained by adding 1 to the address number included in the address setting signal is set as its own address. However, the present invention is not limited to this. For example, one or more predetermined numbers may be added. Further, a method of subtracting, multiplying, or dividing a predetermined number from the initial value may be used. (5) Further, for example, a plurality of address storage areas are prepared in the CPU 15 of each sensor 1, an address number is stored in advance in the address storage area, and address setting is performed based on an address setting signal from the master unit 2. You may do it. Specifically, first, the address setting signal transmitted from the master unit 2 includes the address of the address setting area,
This is transmitted to each sensor 1. Then, each sensor 1 adds a predetermined number to the address included in the received address setting signal, and sets the address contained in the same address as the address after addition in its own address storage area as its own address. The latter address is included in the address setting signal and transmitted to the adjacent sensor 1. (6) In the above embodiment, the sensor 1 to be controlled by inputting the address number of the sensor 1 from the operation unit 23
Is specified, but the sensor 1 to be controlled by another method may be specified. For example, when the setting of the address numbers of the sensors 1 is completed in the master unit 2, the address numbers of the sensors 1 and the code numbers corresponding to these address numbers are stored in advance. When controlling each sensor 1, a code number may be input to control the sensor 1 having an address number corresponding to the code number. (7) In the above embodiment, the operator inputs the address number of the sensor 1 controlled by operating the operation unit 23 and the control command. For example, the operator inputs the address number to the display unit 24 of the master unit 2. Is displayed, and the display of the address numbers is sequentially switched by operating the operation unit 23. When the address number of the sensor 1 to be controlled is displayed,
The control command for the sensor 1 may be input.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electrical configuration of a sensor system according to a first embodiment.

FIG. 2 is a diagram showing an electrical configuration of the sensor system.

FIG. 3 is a flowchart showing the operation of the sensor system.

FIG. 4 is a diagram showing an electrical configuration of a sensor system according to a second embodiment.

FIG. 5 is a diagram showing an electrical configuration of the sensor system.

FIG. 6 is a diagram showing an electrical configuration of the sensor system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical fiber sensor (sensor unit) 2 ... Master unit 3 ... Transmission cable (transmission path) 11 ... Terminal fitting (output part) 12 ... Terminal fitting (input part) 13 ... Transmission part (transmission means) 14 ... Receiving part ( 15: CPU (switch control means, address setting execution means, control execution means) 16: relay (switch means) 22: changeover switch 23: operation unit (input means) 25: CPU

Claims (2)

[Claims] 1. A sensor unit comprising: a plurality of sensor units each including a transmitting unit and a receiving unit; and a master unit, wherein the receiving unit of one sensor unit and the sensor unit adjacent to one side of the sensor unit. Between the transmitting means, and the transmitting means of the one sensor unit and the sensor unit located on the one side opposite to the adjacent but oppositely connected by the receiving means connected via a transmission path, In the sensor system, wherein the master unit is connected to the receiving unit of the sensor unit on one end of the plurality of sensor units via the transmission path, the master unit sets addresses of the plurality of sensor units. Switch between address setting mode and control communication mode for controlling these multiple sensor units Switching means, mode signal transmitting means for transmitting an address setting mode signal in the address setting mode, and transmitting a control communication mode signal in the control communication mode, and control contents associated with a sensor unit to be controlled. Input means for inputting an address, and when the address setting mode is set by the switching means, after an address setting mode signal is transmitted from the mode signal transmitting means, an address including setting information serving as an address setting base is included. Address setting control means for transmitting a setting signal; and when the control communication mode is set by the switching means, the control input to the input means should be performed after the control communication mode signal is transmitted from the mode signal transmission means. Address number assigned to the sensor unit and control contents Control signal transmitting means for transmitting a control signal, wherein the sensor unit is provided between an output part of the transmitting means and an input part of the receiving means, and is provided between the input part and the output part. Switch means for permitting or prohibiting transmission of a signal between the input section and the output section, when the address setting mode signal is received, controlling the switch means to prohibit signal transmission between the input section and the output section. Switch control means for controlling the switch means so as to allow transmission of a signal between the input section and the output section when the control communication mode signal is received, and the address following the address setting mode signal. When a setting signal is received, its own address number is set in accordance with a predetermined procedure based on the setting information included in the address setting signal. Address setting execution means for transmitting the setting information after being updated and including the updated setting information in the address setting signal from the transmission means; and when the control signal is received following the control communication mode signal, the address setting execution means is included in the control signal. A sensor system comprising: a control execution unit that compares an address number with its own address number, and executes control content of the control signal on condition that they match. 2. The output unit of the transmission unit is configured by a light emitting element; the input unit of the reception unit is configured by a light receiving element; the transmission path is configured by an optical fiber; and the switch unit is a liquid crystal shutter. The sensor system according to claim 1, wherein: