CN201100880Y - Analog Resistor Based on PC104 Bus - Google Patents

Abstract

The utility model provides an analog resistor based on the PC104 bus, which includes a standard resistor, and is characterized in that it also includes an input op-amp, a D/A converter, an output op-amp, an in-phase input terminal of the input op-amp and a standard resistor One end is connected to the input voltage, the inverting input terminal and output terminal of the input operational amplifier are connected to the reference voltage terminal of the D/A converter, the output voltage terminal of the D/A converter is connected to the non-inverting input terminal of the output operational amplifier, and the inverting terminal of the output operational amplifier is connected to the reference voltage terminal of the D/A converter. The phase input and output ends are connected to the other end of the standard resistor, and the data end of the D/A converter is connected to an external controller. The utility model has good dynamic resistance simulation ability under the control of the program, and can meet the needs of the turbofan engine control semi-physical simulation test. This method conveniently completes the automatic testing of each simulation process, thereby ensuring the realization of dynamic simulation of the hardware-in-the-loop simulation platform.

Description

Analog Resistor Based on PC104 Bus

(1) Technical field

The utility model relates to an analog resistance realization device based on the PC104 bus, which can realize the control of the resistance value of the output terminal through the PC104 bus.

(2) Background technology

At present, in the semi-physical simulation test of turbofan engine control, the control object engine adopts a mathematical model running on a portable microcomputer, the controller is a real physical component, and the sensors and actuators in the control system can be used according to the needs of the test. components or electronic simulators. There has been no good solution for the simulation of thermal resistance sensors. At present, the simulation of thermal resistance sensors controlled by turbofan engines is mainly to obtain variable resistance values by manually switching the combination of different resistors in the precision resistance box, which greatly reduces the efficiency of the test. In the semi-physical simulation test, it is difficult for this method to realize the dynamic simulation capability of the resistance, which will hinder the progress of the semi-physical simulation platform.

(3) Contents of the invention

The purpose of the utility model is to provide a programmable, high precision, simple and reasonable structure analog resistor based on the PC104 bus.

The purpose of this utility model is achieved like this: it comprises standard resistance, is characterized in that it also comprises input op-amp, D/A converter and output op-amp, the same phase input terminal of input op-amp and one end of standard resistance connect input voltage , the inverting input terminal and output terminal of the input operational amplifier are connected to the reference voltage terminal of the D/A converter, the output voltage terminal of the D/A converter is connected to the non-inverting input terminal of the output operational amplifier, and the inverting input terminal of the output operational amplifier and The output end is connected to the other end of the standard resistor, and the data end of the D/A converter is connected to an external controller.

The utility model also has some technical characteristics:

1. The data end of the D/A converter is connected to an external controller through the PC104 bus.

The utility model provides a temperature sensor in the form of electronic simulation, uses operational amplifiers and the like to form a single-port network, obtains the ratio of input voltage and current through programming, and obtains programmable linear resistance. This impedance synthesis technique results in very high precision output resistance.

The technical solution adopted by the utility model to solve its technical problems is: realize the transmission of the command signal on the PC104 bus, the command signal is processed by decoding it, and the data information for the utility model in the bus data is taken out, and passed through the DC/ After DC conversion and photoelectric isolation processing, it is passed to the high-precision D/A control part of the analog resistor, so as to achieve the purpose of obtaining a stable analog resistor. The utility model realizes the signal processing on the PC104 bus, which ensures the reliability of the control realized by the analog resistance.

The utility model applies the electronic analog resistance technology to a semi-physical simulation interface simulator on a turbofan engine semi-physical dynamic simulation platform composed of a portable microcomputer based on the PC104 bus to simulate a thermal resistance sensor. Effective solutions are proposed in terms of improving the precision of resistance synthesis, improving the anti-interference ability, isolating between multiple channels and merging with PC104 bus. The beneficial effect of the utility model is that in the turbofan engine control semi-physical simulation test, the dynamic simulation ability to the resistance can be easily realized, the efficiency of the test is increased, and it plays a key role in the turbofan engine control semi-physical simulation test. function, and the realization principle is simple.

(4) Description of drawings

Fig. 1 is the system block diagram of the utility model embodiment;

Fig. 2 is a schematic diagram of the realization of the analog resistance of the utility model.

(5) Specific implementation methods

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

According to the system design requirements of the turbofan engine half-in-the-loop dynamic simulation platform, the system block diagram of the present embodiment is shown in Fig. modules etc. The control data command of the computer on the PC104 bus, through the cooperation of the decoding controller and 8255, provides a digital control signal according to the base address set by the decoder, and the signal controls the D/A of the analog resistor through photoelectric isolation, and then Realize the control of the resistance value of the analog resistor.

Referring to FIG. 2 , the analog resistance of this embodiment is composed of an input operational amplifier D1, a D/A converter, an output operational amplifier D2 and a standard resistance R1. The input voltage value U _i applied to one end of the standard resistor is buffered, amplified, and proportionally adjusted, and then fed back to the other end of the standard resistor to control the input current and determine the input resistance value.

The operational amplifier D1 is connected in the form of a voltage follower, and the output voltage is U _i , which is used as the reference voltage of the D/A converter. The transmission coefficient K of the D/A converter is determined by the digital signal input to the D/A, for example, if a 16-bit DAC chip is used, then K=DA value/65536. Therefore, its output voltage is U _D/A =K·U _i . Since D2 works in the state of linear amplification, the potentials of the two input terminals are equal, so the voltage of the inverting terminal of D2 is also K·U _i . The input current of the simulated resistor flows to the output terminal of the operational amplifier _D2 through the standard resistor R1. In this way, the voltage applied to the standard resistor is U _i −K·U _i , and the current is I _i =(U _i −K·U _i )/R ₁ . Since the input current of the non-inverting terminal of the op amp D1 is zero, then for the input terminal, the synthesized resistance can be obtained as:

$\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; K</span>}}$

That is, the standard resistance is multiplied by 1/(1-K) times. When K=0, the resistance remains unchanged; when K=0.9, the resistance is enlarged by 10 times. Therefore, the synthetic resistance value can be changed by changing the input digital quantity of the D/A converter to adjust the K value. The standard resistance _R1 can be selected as 10Ω, 100Ω, so that continuous resistance ranges such as output 100Ω, 1kΩ, etc. can be obtained. In the circuit, the operational amplifier D1 is connected in the form of a voltage follower, D2 is close to unity gain, and connected to a correction capacitor, so a stable analog resistance can be obtained.

Claims (2)

1. An analog resistor based on the PC104 bus, which includes standard resistors, is characterized in that it also includes input operational amplifiers, D/A converters and output operational amplifiers, and the non-inverting input terminal of the input operational amplifiers and one end of the standard resistors are connected to the input Voltage, the inverting input terminal and output terminal of the input operational amplifier are connected to the reference voltage terminal of the D/A converter, the output voltage terminal of the D/A converter is connected to the non-inverting input terminal of the output operational amplifier, and the inverting input terminal of the output operational amplifier The other end of the standard resistor is connected to the output end, and the data end of the D/A converter is connected to an external controller. 2. the analog resistance based on PC104 bus according to claim 1, is characterized in that the data end of described D/A converter is connected external controller by PC104 bus.

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