CN103822861A - Diesel engine exhaust particle concentration detector based on fuzzy PID (proportional-integral-derivative) control - Google Patents

Abstract

The invention discloses a diesel engine exhaust particle concentration detection device based on fuzzy PID control, comprising a gas flow rate sensor, a main control board, an electric flow valve drive circuit, an electric flow valve, a flow pump, a diesel engine exhaust particle sensor, and a diesel engine exhaust particle concentration device Adopt fuzzy PID control system: including input module, fuzzy control module and PID control module; the controller on the main control board takes the deviation e and deviation change rate △ e of the given gas flow rate value and the measured value of the gas flow sensor as the The input variables, the parameters K _p , K _i , K _d of the PID controller, are used as output quantities to control the PID regulator, so that the gas flow rate given to the diesel engine exhaust particle sensor (1) is stable. Due to the adoption of a new sensor structure and circuit The structure and the corresponding micro-controller detect the diesel engine gas flow rate fuzzy PID control algorithm, so that the corresponding concentration of diesel engine exhaust dust particles can be measured under the condition of stable flow rate.

Description

A Diesel Engine Exhaust Particle Concentration Detection Device Based on Fuzzy PID Control

technical field

The invention relates to a particle concentration detection device, in particular to a diesel engine exhaust particle concentration detection device based on fuzzy PID control.

Background technique

With the increasingly serious environmental pollution, dust pollution has attracted people's attention. There are many types of dust sensors in the market, such as "A Dust Sensor" with the patent publication number CN101598657A disclosing a dust sensor, which draws the dust air from the outside into the inside of the sensor and passes through a photoelectric conversion unit; photoelectric conversion The unit provides a light source to irradiate the passing dust-containing air, and generate scattered light, convert the scattered light into a voltage output signal, and output the voltage signal to the voltage signal unit; the signal amplification unit, and the semiconductor photodetector The processing unit is connected with the amplification processing unit, and the dust concentration is calculated based on the voltage signal output by the signal amplification unit and the pre-stored proportional relationship between the voltage signal and the dust concentration. The above-mentioned dust sensor circuit is relatively simple, and is easily disturbed by temperature and external factors, and there is no corresponding detection concentration algorithm, so the accuracy is not high and the stability is not high.

At the same time, when applying the above-mentioned dust sensor to the concentration of diesel exhaust particles, due to the different working conditions of the diesel engine and in order to increase its detection stability, and considering the nonlinearity and drastic changes in the field; it is necessary to use a controller based on fuzzy PID control algorithm to In order to achieve a stable diesel exhaust particle concentration detection, it is necessary to design a diesel engine exhaust particle concentration device and a corresponding control method.

Contents of the invention

The technical problem to be solved by the present invention is to provide a diesel engine particle concentration detection device with higher measurement accuracy and higher efficiency and a corresponding control method.

The technical solution adopted in the present invention to solve the problems of the technologies described above is:

A diesel engine exhaust particle concentration detection device based on fuzzy PID control, including a gas flow rate sensor, a main control board, an electric flow valve drive circuit, an electric flow valve, a flow pump, a diesel engine exhaust particle sensor, and the flow pump is connected to the main control board. connected, the gas flow rate sensor is installed on the gas channel, the gas flow rate sensor is connected with the first A/D module of the main control board; the diesel engine exhaust particle sensor is connected with the second A/D module on the main control board /D module is connected, the main control board is connected with the electric flow valve driving circuit through the output PWM signal circuit, and the electric flow valve is connected with the electric flow valve driving circuit; it is characterized in that: diesel engine exhaust particle concentration device Adopt fuzzy PID control system: including input module, fuzzy control module and PID control module; the corresponding input module adopts touch screen and corresponding circuit, and the actuator of PID controller adopts electric flow valve;

The controller on the main control board takes the deviation _e between the given gas flow rate value and the measured value of the gas flow rate sensor and the deviation change rate Δe as input variables, and the parameters K _p , K _i , K _d of the PID controller as outputs amount, the PID regulator is controlled, so that the gas flow rate given to the diesel engine exhaust particle sensor (1) is stabilized, and the fuzzy PID control algorithm includes the following steps:

1. Set the variable m to the controller, compare the voltage signal f of the gas flow rate sensor, and the deviation is e; the deviation change rate Δe=e(n)-e(n-1); the parameter K _p of the PID controller , K _i , K _d are used as output quantities to control the PID regulator, and the final output quantity u;

2. Fuzzify the input variable deviation e, deviation change rate △e, output K _p , K _i , K _d ; the fuzzy domain of e, △e, K _p , K _i , K _d is {NB, NM, NS, ZO, PS, PM, PB}; the fields of e and △e are {-3, -2, -2, -1, 0, 1, 2, 3}; the theory of K _i , K _p , K _d The domain is {-4.5, -3, -1.5, 0, 1, 3, 4.5};

3. The control rules of this controller are in the form of IfE and△E Then U, and the control rules adopt the fuzzy reasoning synthesis method, which are IF e and△e, Then K _p ; IF e and△e, Then K _i ; IF e and △e, Then K _d ;

4. The fuzzy set obtained by fuzzy reasoning is defuzzified by the maximum degree of membership method;

5. According to the PID parameter setting principle and experience summary, the output u can be obtained:

$\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; Kpe</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; K</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}^{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}}\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; \&Delta;\; e</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; .</span>$

The diesel engine exhaust particle sensor includes a sensor body, an optical path, a light source drive circuit, a photoelectric signal receiving circuit, a signal processing circuit, and a signal output circuit. , diaphragm, and photosensitive area, the light source driving circuit is a light source PWM pulse modulation signal sending circuit, and the photoelectric signal receiving circuit is a voltage amplifying circuit with differential amplification capability, including an amplifier, a photodiode, a capacitor and a resistor, and the The resistor and the photodiode are located at the positive input of the amplifier, and the resistor and capacitor form a differential amplifier at the negative input of the amplifier; the signal processing circuit is a frequency-selective amplifier circuit and a lock-in amplifier circuit, and the frequency-selective amplifier circuit is located at the Between the voltage amplifying circuit and the lock-in amplifier circuit, the lock-in amplifier circuit includes a phase detector, a low-pass filter and a reference signal circuit, and the two ports of the phase detector input are respectively connected to the frequency-selective amplifier The circuit is connected to the input end of the low-pass filter, the output end of the phase detector is connected to the signal output circuit, and the input end of the low-pass filter is connected to the reference signal circuit.

Compared with the prior art, the present invention has the advantages of: due to the adoption of a new sensor structure and circuit structure and a corresponding micro-controller to detect the fuzzy PID control algorithm of the gas flow rate of the diesel engine, the corresponding gas flow rate can be measured under the condition of a stable flow rate. Diesel engine exhaust dust particle concentration.

Description of drawings

Figure 1 is a schematic diagram of the circuit structure of a diesel engine exhaust particle sensor;

Fig. 2 is a diesel engine exhaust particle concentration detection device;

Fig. 3 is a fuzzy PID control system diagram;

Figure 4 is a schematic diagram of the main control board;

Fig. 5 is a diagram of the optical path structure of the diesel engine exhaust particle sensor.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The diesel engine exhaust particle concentration detection device based on fuzzy PID control as shown in Figures 1 to 5 includes a diesel engine exhaust particle sensor 1, a main control board 3, an electric flow valve 6, an electric flow valve drive circuit 4, a flow pump 7, a gas The flow rate sensor 2, the flow pump 7 is connected to the main control board 3, and the gas flow rate sensor 2 is installed on the gas channel.

The above-mentioned diesel engine exhaust particle sensor 1 includes a sensor body, an optical path, and a sensor amplifier circuit. The optical path includes a modulating light source 10, and the advancing direction of the light beam emitted by the modulating light source 10 is successively provided with a lens 8, an aperture 15, a photosensitive area 16, Scattering occurs in the photosensitive area, and the scattered light passes through the lens 8 and finally enters the photodiode 9 .

The sensor amplifying circuit includes a light source driving circuit 1.1, a photoelectric signal receiving circuit, a signal processing circuit, and a signal output circuit 1.9, where the light source driving circuit 1.1 is a light source PWM pulse modulation signal sending circuit, and the photoelectric signal receiving circuit has The voltage amplifying circuit 1.2 of the differential amplification capability includes an amplifier, a photodiode, a capacitor and a resistor, the resistor and the photodiode are located at the positive input of the amplifier, and the resistor and capacitor form a differential amplifier at the negative input of the amplifier; The signal processing circuit is a frequency-selective amplifier circuit 1.3 and a lock-in amplifier circuit 1.4, and the frequency-selective amplifier circuit 1.3 is located between the voltage amplifier circuit 1.2 and the lock-in amplifier circuit 1.4, and the lock-in amplifier circuit 1.4 includes a phase detector device 1.5, low-pass filter 1.6 and reference signal circuit 1.7, the two ports of the input of the phase detector 1.5 are respectively connected with the input terminals of the frequency-selective amplifier circuit 1.3 and the low-pass filter 1.6, and the phase detector The output terminal of 1.5 is connected with the signal output circuit 1.9, and the input terminal of the low-pass filter 1.6 is connected with the reference signal circuit 1.7.

The PWM pulse modulation wave used to modulate the light source is a modulation signal of 60-800Hz, and the duty ratio is 0.3-0.4.

The gas flow rate sensor 2 is connected to the first A/D module 3.1 of the controller 3.3; the diesel exhaust particle sensor is connected to the second A/D module 3.2 on the main control board, and the main control board 3 is connected with the electric flow valve drive circuit 4 by outputting a PWM signal; the electric flow valve 6 is connected with the electric flow valve drive circuit 4 . The main control board 3 outputs another PWM wave to control the flow pump 7;

The fuzzy PID control system of the diesel particle detection system: includes an input module 11, a fuzzy control module 12, and a PID control module 13; the corresponding input module adopts a touch screen 5 and corresponding circuits, and the PID controller actuator adopts an electric flow valve 6; fuzzy- The PID controller writes the corresponding control program in STM32;

The main operating parameters: dust concentration mg/m ³ , gas flow rate m ³ /s, input the given gas flow rate value f to the controller 3.3 through the touch screen, the controller will use the given gas flow rate m value and the field measured value The deviation e and the deviation change rate △e are used as input variables, and the parameters K _p , K _i , K _d of the PID controller are used as output quantities to control the PID regulator so that the gas flow rate given to the dust sensor is stabilized. The fuzzy PID control The algorithm includes the following steps:

1. Set the variable m to the controller 3.3, and compare the gas flow sensor voltage signal f with a deviation of e; the deviation change rate Δe=e(n)-e(n-1); the parameter K of the PID controller _p , K _i , and K _d are used as output quantities to control the PID regulator, and the final output quantity u;

2. Fuzzify the input variable deviation e, deviation change rate △e, output K _p , K _i , K _d , and the fuzzy subsets of e, △e, K _p , K _i , K _d are {NB, NM , NS, ZO, PS, PM, PB}; the domain of e and △e is {-3, -2, -2, -1, 0, 1, 2, 3}; K _i , K _p , K _d The domain of is {-4.5, -3, -1.5, 0, 1, 3, 4.5}; e, △e, K _p , Ki, K _d membership function adopts triangular membership function;

K _p fuzzy response table:

The fuzzy response table of K _i :

Fuzzy response table for K _d :

3. The control rule form of this controller is If e and △ e Then u, and the control rule adopts fuzzy reasoning method, which are IF e and △ e, Then K _p ; IF e and △ e, Then K _i ; IF e and△e, Then K _d ;

4. The fuzzy set obtained by fuzzy reasoning is defuzzified by the maximum degree of membership method;

5 According to the PID parameter setting principle and experience summary, the output u can be obtained:

$\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; Kpe</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; K</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}^{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}}\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; \&Delta;\; e</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; .</span>$

Claims (2)

1. the Fractions of Diesel Engine Exhaust Particulates concentration detection apparatus based on fuzzy control, comprise air flow rate sensor (2), master control borad (3), electric flow valve-driving circuit (4), electric flow valve (6), flow pump (7), Fractions of Diesel Engine Exhaust Particulates sensor (1), described flow pump (7) is connected with master control borad (3), described air flow rate sensor (2) is installed on gas channels, and described air flow rate sensor (2) is connected with an A/D module (3.1) of described master control borad; Described Fractions of Diesel Engine Exhaust Particulates sensor (1) is connected with the 2nd A/D module (3.2) on master control borad, described master control borad (3) is connected with described electric flow valve-driving circuit (4) by output pwm signal circuit, and described electric flow valve (6) is connected with electric flow valve-driving circuit (4); It is characterized in that: Fractions of Diesel Engine Exhaust Particulates concentration device adopts Fuzzy PID Control System: comprise load module (11), fuzzy control model (12), pid control module (13); Corresponding load module (11) adopts touch-screen (5) and related circuit, and PID controller topworks adopts electric flow valve (6);

Controller (3.3) on described master control borad is using the deviation e of given gas flow rate value and air flow rate sensor measured value and deviation variation rate △ e as input variable, parameter K p, the Ki of PID controller, Kd are as output quantity, PID regulator is controlled, thereby the gas flow rate that gives Fractions of Diesel Engine Exhaust Particulates sensor (1) is stablized, and this Fuzzy PID comprises the steps:

1), set variable m to controller (3.3), described air flow rate sensor voltage signal f compares, and deviation is e; Deviation variation rate △ e=e (n)-e (n-1); Parameter K p, the Ki of PID controller, Kd, as output quantity, control PID regulator, final output quantity u;

2), by input variable deviation e, deviation variation rate △ e, output quantity Kp, Ki, Kd carries out obfuscation; E, △ e, Kp, Ki, the fuzzy field of Kd is { NB, NM, NS, ZO, PS, PM, PB}; The territory of e, △ e be 3 ,-2 ,-2 ,-1,0,1,2,3}; Ki, Kp, the domain of Kd be 4.5 ,-3 ,-1.5,0,1,3,4.5};

3), the control law form of this controller is IfE and △ E Then U, control law adopts fuzzy reasoning method, is respectively IF e and △ e, Then Kp; IF e and △ e, Then Ki; IF e and △ e, Then Kd;

4), obtain by fuzzy reasoning for fuzzy set, adopt maximum membership degree method to carry out reverse gelatinization;

5), according to pid parameter setting principle and summary of experience, can obtain output quantity u:

$u=\mathrm{Kpe}\left(n\right)+K{i}^{\underset{i=0}{\overset{i=n}{\mathrm{\&Sigma;}}}e\left(i\right)}+\mathrm{Kd}\left[\mathrm{\&Delta;e}\left(i\right)\right].$

2. a kind of Fractions of Diesel Engine Exhaust Particulates concentration detection apparatus based on fuzzy control according to claim 1, it is characterized in that: described Fractions of Diesel Engine Exhaust Particulates sensor (1), comprise sensor body, light path, light source driving circuit (1.1), photo-electric signal receiving circuit, signal processing circuit, signal output apparatus (1.9), described light path comprises modulated light source (10), the working direction that described modulated light source (10) is sent light beam is provided with lens (8) successively, diaphragm (15), photosensitive area (16), described light source driving circuit (1.1) is light source pwm pulse modulation signal transtation mission circuit, described photo-electric signal receiving circuit is the voltage amplification type circuit (1.2) with differential amplifying power, comprise amplifier and photodiode and electric capacity and resistance, described resistance and photodiode are positioned at the normal phase input end of amplifier, described resistance capacitance is at amplifier negative input composition differentiating amplifier, described signal processing circuit is selective frequency amplifier circuit (1.3) and phase-locked amplifying circuit (1.4), described selective frequency amplifier circuit (1.3) is positioned between described voltage amplification type circuit (1.2) and phase-locked amplifying circuit (1.4), described phase-locked amplifying circuit (1.4) comprises phase detector (1.5), low-pass filter (1.6) and reference signal circuit (1.7), two ports of described phase detector (1.5) input are connected with low-pass filter (1.6) input end with described selective frequency amplifier circuit (1.3) respectively, the output terminal of described phase detector (1.5) is connected with described signal output apparatus (1.9), described low-pass filter (1.6) input end is connected with reference signal circuit (1.7).

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