JPH08202414A - Programmable controller - Google Patents

Abstract

PURPOSE: To shorten the bus occupation time of a fuzzy inference unit by providing a digital input and an output part in the fuzzy inference unit separately from an input and an output unit connected to a bus. CONSTITUTION: This programmable controller is equipped with a central processing unit 1 which is equipped with a microprocessor and a memory and operates according to a sequence program, the input unit 2 which inputs data from a sensor, etc., the output unit 3 which outputs a manipulated variable to a controlled system such as a heater, and the fuzzy inference unit which outputs the manipulated variable obtained through fuzzy inference using the input data. In this case, the central processing unit 1, input unit 2, output unit 3, and fuzzy inference unit are connected through the bus 5. The fuzzy inference unit is provided with input part 6 and output part 7 separately from the input unit 2 and output unit 3 and data used by the fuzzy inference unit can be inputted directly to the fuzzy inference unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller having a fuzzy inference unit.

[0002]

2. Description of the Related Art Generally, a programmable controller makes a condition judgment according to an input value from a sensor or the like in accordance with a series of sequences programmed in advance, and outputs data of an operation amount for controlling a controlled object. An appropriate amount of operation can be obtained by utilizing the knowledge of a skilled person in the above-mentioned condition judgment for the controlled object. Therefore,
It has been proposed to provide a fuzzy inference unit as a programmable controller that can utilize the knowledge of experts.

That is, as shown in FIG. 6, the programmable controller includes a central processing unit 1 including a microprocessor and a memory and operating according to a sequence program, an input unit 2 to which data from a sensor or the like is input, and a control target. An output unit 3 for outputting a manipulated variable is provided, and a fuzzy inference unit 4 for outputting a manipulated variable obtained by performing fuzzy inference using input data. The central processing unit 1, the input unit 2, the output unit and the fuzzy inference unit 4 are connected via a bus 5.

As shown in FIG. 7, the fuzzy inference unit 4 includes a control unit 11 including a microprocessor and an RO.
A program memory 12 made of M, a fuzzy inference operation unit 13 for executing fuzzy inference, and a knowledge memory 14 made of a RAM storing knowledge used for fuzzy inference. Further, the internal bus 15 of the fuzzy inference unit 4 is connected to the bus interface unit 17 via the shared memory 16, and the data transmitted / received via the bus 5 is temporarily stored in the shared memory 16 so that it is asynchronous. Data can be sent and received. The program memory 12 stores programs necessary for performing fuzzy inference and data transmission / reception, and membership functions and control rules as knowledge necessary for fuzzy inference are stored in a personal computer via a tool interface unit 18. It is written in the knowledge memory 14 by such a program support tool 9.

[0005]

In the programmable controller described above, since the central processing unit 1 and the fuzzy inference unit 4 use a common bus, the central processing unit 1 and the fuzzy inference unit 4 simultaneously operate on the bus. Cannot be used, which causes a bottleneck, resulting in a decrease in processing speed.

That is, when the central processing unit 1 outputs the manipulated variable data to the controlled object through the output unit 3 or when the input data from the sensor or the like is fetched through the input unit 2, the fuzzy logic is used. The inference unit 4 cannot perform processing such as inputting new data and updating the inference. Therefore,
The central processing unit 1 must input data one by one each time the fuzzy inference unit 4 is accessed and read out inference results one by one from the fuzzy inference unit 4, thereby inputting inference data and reading inference results. There is a problem in that it takes a considerable amount of time only for processing, and cannot be applied to a field requiring high-speed response such as motor control.

Further, various thermocouples and resistance temperature detectors are used as sensors for performing temperature control often used in process control. To take in input data from this type of sensor, the input unit 2 is used. It is necessary to connect a transducer for signal conversion or a unit dedicated to temperature input, resulting in a problem that the cost and size of the programmable controller increase.

The present invention has been made in view of the above circumstances, and an object thereof is to shorten the time for which a fuzzy inference unit occupies a bus to speed up the processing and to input data from a sensor to other sources. (EN) Provided is a programmable controller which reduces the cost without increasing the size by incorporating it in a fuzzy inference unit without using the above configuration.

[0009]

According to a first aspect of the present invention, in a programmable controller including a central processing unit, a fuzzy inference unit, an input / output unit, and a bus connecting each unit, a fuzzy inference unit is provided. , A digital input / output unit different from the input / output unit, a fuzzy inference operation unit, a bus interface unit, and an internal bus for connecting each component of the fuzzy inference unit.

According to a second aspect of the present invention, there is provided a central processing unit,
In a programmable controller including a fuzzy inference unit, an input / output unit, and a bus connecting each unit, in the fuzzy inference unit, an analog input / output unit different from the I / O unit, a fuzzy inference operation unit, and a bus The fuzzy inference unit has an internal bus for connecting each component of the fuzzy inference unit, and the analog input / output unit of the fuzzy inference unit has an A / D conversion circuit built in the input unit and an output unit of the input / output unit. Has a built-in D / A conversion circuit.

According to a third aspect of the present invention, the fuzzy inference unit has an analog input / output section, the input section of the analog input / output section has a built-in A / D conversion circuit, and the output section of the input / output section has an output section. It is characterized in that a D / A conversion circuit is incorporated therein. According to a fourth aspect of the present invention, in a programmable controller including a central processing unit, a fuzzy inference unit, an input / output unit, and a bus connecting each unit, in the fuzzy inference unit, an analog different from the input / output unit is provided. It has an input / output unit, a fuzzy inference operation unit, a bus interface unit, and an internal bus that connects each component of the fuzzy inference unit, and an analog output of the analog input / output unit in the fuzzy inference unit The sensor interface unit for connecting the sensor and the A / D conversion circuit are built-in, and the output unit of the input / output unit has the D / A conversion circuit and the output interface unit for outputting the manipulated variable. The interface section is mounted on a detachable circuit board.

The invention of claim 5 is characterized in that a digital input / output unit is provided in the fuzzy inference unit.

[0013]

According to the structure of the invention of claim 1, the digital input / output unit is provided in the fuzzy inference unit in addition to the input / output unit connected to the bus, so that the digital quantity is directly taken into the fuzzy inference unit. Inference can be performed, and passing of data to and from the central processing unit is not required, and the bus usage time can be reduced. That is, it is possible to shorten the data transfer time and perform high-speed processing as a whole.

According to the second aspect of the present invention, the analog input / output unit is provided in the fuzzy inference unit in addition to the I / O unit connected to the bus. Inference can be performed, and passing of data to and from the central processing unit is not required, and the bus usage time can be reduced. That is, it is possible to shorten the data transfer time and perform high-speed processing as a whole.

According to the configuration of the third aspect of the invention, since the digital input / output unit and the analog input / output unit are provided in the fuzzy inference unit, both the digital amount and the analog amount can be directly taken into the fuzzy inference unit. By doing so, the bus is not occupied to input data, and as a result, high-speed processing becomes possible. According to the configuration of the invention of claim 4, the sensor interface portion for connecting the sensor and the output interface portion for outputting the manipulated variable are provided on the detachable circuit board, so that it is required depending on the input or output. The interface unit of can be selected and provided.
Moreover, the sensor interface unit can be connected to an analog output sensor, and since it is converted into a digital amount by the A / D conversion circuit, a dedicated transducer for sensor input is not required and can be provided at low cost. ,
In addition, it is possible to prevent an increase in size.

According to the fifth aspect of the present invention, since the analog output sensor can be output to the fuzzy inference unit and the digital input / output section is provided so that the digital amount can be taken in, the input from the bus is eliminated. In addition to enabling fuzzy inference, both analog input and digital input can be captured, increasing versatility.

[0017]

【Example】

(Embodiment 1) As shown in FIG. 1, a programmable controller includes a microprocessor and a memory (system memory, program memory, data memory, etc.), a central processing unit 1 that operates according to a sequence program, and data from sensors and the like. An input unit 2 to be input, an output unit 3 for outputting a manipulated variable to a controlled object such as a heater, and a fuzzy inference unit for outputting a manipulated variable obtained by performing fuzzy inference using input data. 4 and. Although the input unit 2 and the output unit 3 are separately provided here, they may be integrally provided as an input / output unit. In this case, the input section of the input / output unit has the same function as the input unit 2,
The output section has the same function as the output unit 3. The central processing unit 1, the input unit 2, the output unit 3, and the fuzzy inference unit 4 are connected via a bus 5. Further, the fuzzy inference unit 4 is provided with an input unit 6 and an output unit 7 in addition to the input unit 2 and the output unit 3 so that the data used for the fuzzy inference can be directly input to the fuzzy inference unit 4. The input unit 2 and the output unit 3 exchange data that does not perform fuzzy inference and exchange data that may perform fuzzy inference at low speed.

As shown in FIG. 2, the fuzzy inference unit 4 includes a control unit 11 including a microprocessor and an RO.
A program memory 12 made of M, a fuzzy inference operation unit 13 for executing fuzzy inference, and a knowledge memory 14 made of a RAM storing knowledge used for fuzzy inference. Further, the internal bus 15 of the fuzzy inference unit 4 is connected to the bus interface unit 17 via the shared memory 16, and the data transmitted / received via the bus 5 is temporarily stored in the shared memory 16 so that it is asynchronous. Data can be sent and received.

The program memory 12 stores programs necessary for performing fuzzy inference and data transmission / reception, and membership functions and control rules as knowledge necessary for fuzzy inference are passed through the tool interface unit 18. It is written in the knowledge memory 14 by the program support tool 9 such as a personal computer. When an appropriate input is made from the input unit 6 or the bus 5 in this state, the fuzzy inference operation unit 13 executes the fuzzy operation using the fuzzy inference algorithm, and the operation amount is output to the output unit 7 or the bus 5. Is done.

By the way, the input section 6 and the output section 7 in the fuzzy inference unit 4 are a digital input section 6a and a digital output section 7a, respectively, and when a digital amount from the outside is inputted through the digital input section 6a, the fuzzy logic is inputted. The digital output unit 7a is configured to output a digital amount, which is the result of the inference operation, as an operation amount.
Further, when high speed is not required for the fuzzy inference operation, the data fetched from the input unit 2 is input to the fuzzy inference unit 4 via the bus 5, and the manipulated variable is output from the fuzzy inference unit 4 to the outside through the output unit 3. .

Second Embodiment In the first embodiment, the fuzzy inference unit 4 uses the input / output unit 6a and the output unit 6a for transmitting / receiving the digital amount so that the digital amount can be input / output. As shown in FIG. 3, the example has a configuration in which an A / D conversion circuit 6b is used as the input section 6 and a D / A conversion circuit 7b is used as the output section 7. The rest of the configuration is the same as that of the first embodiment, and is different from the first embodiment only in the format of the data directly transmitted / received by the fuzzy inference unit 4.

As described above, the A / D conversion circuit 6b provided in the fuzzy inference unit 4 in the fuzzy inference operation.
Since the data is input and the manipulated variable is output using the D / A conversion circuit 7b, the bus 5 is not occupied for fuzzy inference, and as a result, the manipulated variable for the input is quickly determined. It can be output as a high speed response. That is, as is clear from a comparison between FIG. 4 and FIG. 8 showing the flow of processing, in the configuration of this embodiment, data is input to the fuzzy inference unit 4 and the A / D conversion in the A / D conversion circuit 6b is performed. After the conversion, the data transfer in the fuzzy inference unit 4 is performed, and thereafter,
When the manipulated variable is obtained by fuzzy inference, it is given to the controlled object as an analog output after D / A conversion in the D / A conversion circuit 7b.

On the other hand, in the processing procedure of the conventional configuration shown in FIG. 8, the data fetched from the input unit 2 is A / D-converted and then transferred to the central processing unit 1 and further transferred to the fuzzy inference unit 4 to be fuzzy. Inference operations will be performed. The result obtained by the fuzzy inference unit 4 is again transferred to the central processing unit 1 and sent to the output unit 3 where it is D / A converted and then output to the controlled object.

As is clear from the above description, in the configuration of this embodiment, the data of the input and output of the fuzzy inference is transferred without passing through the central processing unit 1, so that the processing is performed for the time passing through the bus 5. The time is shortened, and as a result, the processing time can be greatly shortened. (Embodiment 3) In this embodiment, a configuration of a fuzzy inference unit 4 which is particularly suitable for temperature control among analog controls will be illustrated. That is, the fuzzy inference unit 4 of this embodiment
As shown in FIG. 5, a sensor interface unit (for temperature correction and amplification) 6c for taking in an input from a temperature sensor such as a thermocouple or a resistance temperature detector and an A / D conversion circuit 6b are provided as an input unit. D / A conversion circuit 7b
Also, an output interface section 7c for giving an operation amount to a controlled object such as a heater is provided as the output section 7. The sensor interface unit 6c and the output interface unit 7c are mounted on separate circuit boards, and these circuit boards are detachable from the fuzzy inference unit 4. Therefore, the sensor interface unit 6c
The output interface unit 7c can be exchanged as necessary. For example, if various interface parts for general-purpose temperature sensors are easily provided, they can be applied to various temperature controls. Moreover, the temperature data is a fuzzy inference unit 4
Since it is directly input to, the time required for fuzzy inference operation is short and high-speed processing is possible. Other configurations and operations are the same as those of the first embodiment.

[0025]

According to the first aspect of the present invention, since the digital input / output unit is provided in the fuzzy inference unit in addition to the input / output unit connected to the bus, the digital amount is directly taken into the fuzzy inference unit to perform the fuzzy inference. It can be executed, and the passing of data to and from the central processing unit becomes unnecessary, and the use time of the bus can be reduced. That is, there is an advantage that the data transfer time is shortened and high-speed processing as a whole becomes possible.

According to the second aspect of the present invention, the analog input / output unit is provided in the fuzzy inference unit in addition to the I / O unit connected to the bus, so that the analog quantity is directly taken into the fuzzy inference unit to execute the fuzzy inference. Therefore, it is not necessary to transfer data to and from the central processing unit, and the use time of the bus can be reduced. That is, there is an advantage that the data transfer time can be shortened and high-speed processing can be performed as a whole.

According to the third aspect of the invention, since the digital input / output unit and the analog input / output unit are provided in the fuzzy inference unit, data input can be performed by directly fetching both the digital amount and the analog amount into the fuzzy inference unit. There is an advantage that high-speed processing is possible without occupying the bus. According to the invention of claim 4, the sensor interface portion for connecting the sensor and the output interface portion for outputting the manipulated variable are provided on the detachable circuit board, so that a required interface portion can be provided according to the input or the output. It can be selected and provided. Moreover, the sensor interface unit can be connected to an analog output sensor, and since it is converted into a digital amount by the A / D conversion circuit, a dedicated transducer for sensor input is not required and can be provided at low cost. In addition, there is an advantage that it is possible to prevent an increase in size.

According to the fifth aspect of the present invention, the analog output sensor can be output to the fuzzy inference unit, and the digital input / output unit is provided so that the digital amount can be captured. Therefore, the fuzzy inference can be performed without input from the bus. In addition, there is an advantage that both the analog input and the digital input can be taken in and the versatility is enhanced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a first embodiment.

FIG. 2 is a block diagram showing a fuzzy inference unit used in the first embodiment.

FIG. 3 is a block diagram showing a fuzzy inference unit used in a second embodiment.

FIG. 4 is an operation explanatory view showing the processing procedure of the second embodiment.

FIG. 5 is a block diagram showing a fuzzy inference unit used in a third embodiment.

FIG. 6 is a block diagram showing an overall configuration of a conventional example.

FIG. 7 is a block diagram showing a fuzzy inference unit used in a conventional example.

FIG. 8 is an operation explanatory diagram showing a processing procedure of a conventional example.

[Explanation of symbols]

 1 central processing unit 2 input unit 3 output unit 4 fuzzy inference unit 5 bus 6 output section 6a digital input section 6b A / D conversion circuit 6c sensor interface section 7 input section 7a digital output section 7b D / A conversion circuit 7c output interface Section 13 Fuzzy inference operation section 15 Internal bus 17 Bus interface

Claims (5)

[Claims] 1. A programmable controller having a central processing unit, a fuzzy inference unit, an input / output unit, and a bus connecting each unit, wherein a digital input / output different from the input / output unit is provided in the fuzzy inference unit. A programmable controller comprising: a unit, a fuzzy inference operation unit, a bus interface unit, and an internal bus connecting each component of the fuzzy inference unit. 2. A programmable controller having a central processing unit, a fuzzy inference unit, an input / output unit, and a bus connecting each unit, wherein an analog input / output different from the input / output unit is provided in the fuzzy inference unit. Unit, a fuzzy inference operation unit, a bus interface unit, and an internal bus connecting each component of the fuzzy inference unit, and an A / D conversion circuit in an input unit of an analog input / output unit in the fuzzy inference unit. And a D / A conversion circuit is built in the output section of the input / output section. 3. A fuzzy inference unit has an analog input / output section, an input section of the analog input / output section has an A / D conversion circuit built in, and an output section of the input / output section has a D / A conversion circuit. The programmable controller according to claim 1, wherein the programmable controller is incorporated. 4. A programmable controller having a central processing unit, a fuzzy inference unit, an input / output unit, and a bus connecting each unit, wherein an analog input / output different from the input / output unit is provided in the fuzzy inference unit. Section, a fuzzy inference operation section, a bus interface section, and an internal bus that connects each component of the fuzzy inference unit, and an analog output sensor is provided at the input section of the analog input / output section in the fuzzy inference unit. The sensor interface unit to be connected and the A / D conversion circuit are built-in. The output unit of the input / output unit has the D / A conversion circuit and the output interface unit for outputting the manipulated variable, and the sensor interface unit and the output interface unit. Is a programmable controller that is mounted on a detachable circuit board. 5. The programmable controller according to claim 4, further comprising a digital input / output unit in the fuzzy inference unit.