JP4447302B2 - Analog control system - Google Patents

Description

The present invention receives an information signal such as the temperature and pressure measured by the measuring instruments and sensors, and outputs an analog control signal to a device in which the measuring instrument or sensor is installed in accordance with the measured measurement value It relates to an analog control system.

In general, control of equipment such as air conditioners and heat treatment furnaces takes in analog signals such as temperature and pressure measured by various sensors such as temperature sensors and pressure sensors into a dedicated measurement value output device, which is used for the above temperature and pressure. Is converted into a digital signal representing the magnitude of the measured value, etc., and then sent to a monitoring device or control device equipped with a microcomputer, which is converted into an analog control signal for controlling the device. Had to control.
FIG. 6 is a diagram showing an example of this. The output of the temperature sensor 51 provided in the air conditioner 50 is input to the analog input unit 52a of the sequencer 52, and the analog signal corresponding to the measured indoor temperature is amplified. A / D conversion is performed, and the magnitude of the temperature converted into the digital signal is compressed by the fan of the indoor unit 53 and the outdoor unit 54 using a dedicated analog output card (not shown) attached to the analog output unit 52b. By converting into an analog control signal for controlling the machine and the fan motor and outputting it to the control device 55 of the air conditioner 50, the room temperature is adjusted so that the room temperature becomes the set temperature.

  Further, when monitoring a plurality of devices, such as monitoring of a heat treatment furnace in a production line, the temperature of each heat treatment furnace 60a-60n measured by the temperature sensors 61a-61n as shown in FIG. The signal converters 62a to 62n corresponding to the analog input unit 52a are converted into digital signals and then sent to the microcomputer 70 to be compared with the set temperature. The microcomputer 70 sends a digital control signal for controlling the temperature of each of the heat treatment furnaces 60a to 60n to the temperature monitoring means 80 based on the comparison result. The temperature monitoring means 80 converts the digital control signal into an analog control signal for controlling the current values of the heaters of the heat treatment furnaces 60a to 60n by a D / A converter (not shown), and converts the analog control signals to the heat treatment furnaces. The temperature is controlled by sending to 60a to 60n.

However, in the conventional apparatus, since the detected temperature level needs to be converted into a digital signal once, not only a dedicated device such as an A / D converter is necessary, but also the digital In order to output the analog control signal as described above using the information signal, a D / A converter and a dedicated analog output card are required, so that the apparatus is not only expensive but complicated. There was a problem.
Also, for applications where real-time measurement is not always necessary, such as when monitoring a heat treatment furnace in a production line, monitoring may be performed every predetermined time, and control is performed by always outputting measured values as described above. The system to do was over-spec and not efficient.

  The present invention has been made in view of the conventional problems, and with a simple configuration, takes in information signals such as temperature and pressure measured by a measuring instrument and various sensors every predetermined time, and measures the above measured values. An object of the present invention is to provide an analog control system that outputs an analog control signal for controlling the device to a device in which the measuring instrument or sensor is installed according to a value.

The invention according to claim 1 of the present application inputs a measured value of an analog signal measured by a measuring instrument or a sensor, compares the measured value with a preset setting value, and installs the device on which the measuring instrument or the sensor is installed. An analog control system that outputs an analog control signal to be controlled, comprising a measurement value output device and an analog control signal output device, wherein the measurement value output device converts a measurement value of the input analog signal to a value of the measurement value. by a time corresponding to the size, and the detection signal conversion means for converting the oN / OFF signal oN state or OFF state is continued for the duration T _w, oN for outputting the oN / OFF signals at every predetermined time T _p / and an OFF signal output unit, analog control signal output device, duration detection for detecting the duration T _w of the output ON / OFF signals from the measured value output device Stage and, the detected duration and T _w and the preset comparison means asking you to time difference or duration ratio between the duration T _n corresponding to the set value, the time difference or continuously determined by the comparing means the analog control signal for controlling the equipment the instrument or sensor is installed according to the size of the time ratio, and having a control signal output means for outputting to the device for each of the predetermined time T _p Is.
According to a second aspect of the present invention, in the analog control system according to the first aspect, the analog control signal output device includes a plurality of measured values output from a device in which a plurality of measuring instruments or sensors are installed, a plurality of measured values. Input multiple types of measurement values or multiple types of measurement values, and output analog control signals corresponding to the above multiple measurement values, multiple types of measurement values, or multiple types of multiple measurement values. According to a preset order, it is configured to output to a device in which the plurality of measuring instruments or sensors are installed.
A third aspect of the present invention is the analog control system according to the first or second aspect, wherein the measured value is one or more of temperature, pressure, and current.

According to the present invention, continues for input instrument or only the time corresponding to the magnitude of the measured measurement values by sensor O N state or OFF state duration T _w, such as temperature and pressure in the heat treatment furnace A measured value output device that outputs an ON / OFF signal to be output at every predetermined time T _p , and a duration Tw of the ON / OFF signal output from the measured value output device is detected, and the detected duration Tw is previously detected. Rutotomoni obtains the set time difference or duration ratio between the duration Tn corresponding to the set value, depending on the magnitude of the time difference or duration ratio obtained by the comparing means, the instrument or sensor is installed An analog control signal output device for outputting an analog control signal for controlling the device to the device at the predetermined time T _p , and an analog control signal corresponding to the magnitude of the input measurement value. Since the control signal is output to the device, the device can be controlled with a simple configuration to accurately adjust the room temperature, the pressure in the heat treatment furnace, and the like.

Hereinafter, the best mode of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an analog control system according to the best mode. In FIG. 1, reference numeral 10 denotes a temperature sensor 61 (61a to 61n) provided in a heat treatment furnace 60 (60a to 60n) to be controlled. Is a measurement value output device that inputs an output (measurement value) from each of them and outputs an ON / OFF signal in which the ON state or the OFF state continues for a time corresponding to the magnitude of the measurement value. An analog control signal output device 30 that outputs an analog control signal corresponding to the time during which the ON / OFF signal sent from the device 10 is ON or OFF continues, and 30 outputs the output from the analog control signal output device 20 in advance. Output signal switching means for outputting to each of the heat treatment furnaces 60a to 60n in a predetermined order set.
The measured value output device 10 amplifies the output of the temperature sensor 61 to detect the temperature magnitude T in the heat treatment furnace 60, and sets the detected temperature magnitude (analog signal) to a time interval ( Continuation time) ON / OFF signal output means for sequentially outputting an ON / OFF signal for which the ON state or the OFF state continues for the time interval T _w at every predetermined time T _p , and a detection signal conversion unit 11 that converts it into T _w 12 and the output level is switched from the OFF state to the ON state every predetermined time T _p , and after the continuation time T _w corresponding to the temperature calculated by the detection signal conversion unit 11 has elapsed, The output is returned from the ON state to the OFF state. Thereby, as shown in FIG. 2, for example, when the temperature in the heat treatment furnace 60 changes to 85 ° C., 87 ° C., and 83 ° C., the measured value output device 10 continues for every predetermined time T _p. An ON / OFF signal (pulse signal) having a (pulse width) of 2.5 sec, 2.7 sec, and 2.3 sec can be output to the analog control signal output device 20.

The analog control signal output device 20 compares the duration detection unit 21 that detects the duration of the ON / OFF signal, and the comparison that compares the duration T _w with the duration T _n corresponding to a preset temperature. And a control signal output unit 23 that outputs an analog control signal for controlling the heat treatment furnace 60 based on the comparison result, and corresponds to the duration T _w detected by the duration detection unit 21. An analog control signal output, specifically, an analog control signal output corresponding to the time difference from the durations T _w and T _n or the magnitude of the duration ratio is output. At this time, as the analog control signal, an instrument standard signal which is a current value of 4 to 20 mA or an analog signal of 1 to 5 V is used. Thus, from the measured value output unit 10, as shown in FIG. 2, the duration (pulse width) T _w is 2.5sec, 2.7sec, ON / OFF signal is 2.3Sec (pulse signal) is output If the reference analog control signal sent to the heat treatment furnaces 60a to 60n when the set temperature is 85 ° C. is 10 mA, the analog control signal output device 20 sends a predetermined time T as shown in FIG. Analog control signals of 10 mA, 8 mA, and 12 mA (or analog control signals of 2.5 V, 2.3 V, and 2.7 V) are sequentially output to the output signal switching means 30 for each _p .
Each of the heat treatment furnaces 60a to 60n receives the analog control signal output from the output signal switching means 30, and controls the energization current to a heater (not shown) so that the temperature in each of the heat treatment furnaces 60a to 60n becomes the set temperature. Adjust so that

Thus, according to this best mode, the temperature of each of the heat treatment furnaces 60a to 60n is measured by the temperature sensors 61a to 61n, and the measured value output device 10 measures the magnitude of the temperature (analog signal). was transformed into the time interval (duration) T _w, at every predetermined time T _p, with sequentially outputs oN / OFF signals by the time interval oN state or OFF state is continued, by an analog control signal output device 20 analog to detect the duration T _w of the oN / OFF signal, is compared with the duration T _n corresponding to a preset temperature and the duration T _w, controls the heat treatment furnace 60a~60n Since the control signal is output, the temperature of each of the heat treatment furnaces 60a to 60n is controlled without using an A / D converter, a D / A converter, or a dedicated analog output card. An analog control system can be constructed.
Further, since the analog control signal is output every predetermined time T _p , it is possible to monitor and control the heat treatment furnace of the production line without performing complicated sequence control.

In the above-described best mode, the case where the analog control system is applied to the temperature control of the heat treatment furnaces 60a to 60n has been described. However, the present invention is not limited to this, and the present invention includes a differential transformer, a pressure sensor, a temperature sensor, and the like. The present invention can also be applied to a control system that controls a device in which various sensors are installed. In addition, the target measurement value is not limited to one type, and a plurality of types of measurement values such as temperature and pressure, or analog control signals corresponding to a plurality of types of measurement values are set in a preset order. It is also possible to configure to output to the device according to
Further, in the above example, after comparing the duration T _n corresponding to the ON / OFF signal of the ON signal or OFF signal preset temperature it detects the duration T _w of the duration T An analog control signal output corresponding to the time difference between _w and T _n or the duration ratio is output, but an analog signal corresponding to the duration T _w is output first, and this is set in advance. The analog control signal may be output in comparison with a reference voltage corresponding to the set temperature.
Further, as shown in FIG. 4, a duration detection unit 41 that detects an ON signal of the input ON / OFF signal or a duration T _w of the OFF signal, and an analog signal corresponding to the duration T _w are output. By configuring the analog signal output device 40 including the analog signal output unit 42, it corresponds to the magnitude of the measurement value similar to the output from the measurement value output device 10 as shown in FIG. A device that reversely converts an ON / OFF signal having a continuous time _Tw into an instrumentation standard signal corresponding to the magnitude of the measurement value as shown in FIG. 5B can be obtained.

  As described above, according to the present invention, an analog control signal corresponding to the magnitude of a measured value such as temperature and pressure can be output to a device such as a heat treatment furnace with a simple configuration, so that it is designed at a low cost. -An analog control system that is easy to manufacture can be realized.

It is a figure which shows the analog control system which concerns on the best form of this invention. It is a figure which shows an example of the ON / OFF signal which concerns on this best form. It is a figure which shows an example of the analog control signal which concerns on this best form. It is a figure which shows the structure of the analog output device by this invention. It is a figure which shows operation | movement of the analog output device by this invention. It is a figure which shows the structure of the conventional analog control system. It is a figure which shows the other structure of the conventional analog control system.

Explanation of symbols

10 measurement value output device, 11 detection signal converter, 12 ON / OFF signal output means,
20 analog control signal output device, 21 duration detection unit, 22 comparison unit,
23 control signal output unit, 30 output signal switching means.

Claims (3)

An analog control system that inputs an analog signal measurement value measured by a measuring instrument or sensor, compares it with a preset setting value, and outputs an analog control signal for controlling the device on which the measuring instrument or sensor is installed Because
A measurement value output device and an analog control signal output device are provided,
The measured value output device
The measured value of the input analog signal by a time corresponding to the magnitude of the measurement value, a detection signal conversion means for converting the ON / OFF signal ON state or OFF state is continued for the duration T _w,
ON / OFF signal output means for outputting the ON / OFF signal every predetermined time T _p ,
Analog control signal output device
A continuation time detection means for detecting a duration T _w of the output ON / OFF signals from the measurement value output device,
Comparing means asking you to time difference or duration ratio between the duration T _n corresponding to the detected duration T _w and the preset value,
Control signal to output an analog control signal for controlling the equipment the instrument or sensor is installed according to the size of the determined time difference or duration ratio the comparing means, to the device for each of the predetermined time T _p And an analog control system.   The analog control signal output device inputs a plurality of measurement values, a plurality of types of measurement values, or a plurality of types of measurement values output from a device in which a plurality of measuring instruments or sensors are installed, Outputs multiple measurement values, multiple types of measurement values, or analog control signals corresponding to multiple types of multiple measurement values to a device equipped with the multiple measuring devices or sensors according to a preset order. The analog control system according to claim 1, wherein:   The analog control system according to claim 1, wherein the measured value is one or more of temperature, pressure, and current.

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