Automatic control system and method for rice polishing brightness value

Abstract

The invention discloses a rice polishing brightness value automatic control system which comprises a rice polishing machine, a control integrated cabinet, a quality analyzer and a sampling mechanism, a raw material feeding port is formed in the upper portion of the rice polishing machine, a discharging port is formed in the lower portion of the rice polishing machine, the discharging port is connected to a feeding port of an elevator through an articulated chute, and the discharging port of the elevator is connected with the sampling mechanism; the sampling mechanism is connected to the chute of the next process in a normally open state, and the sampling mechanism is connected to the feed port of the quality analyzer in a sampling action state. According to the invention, the rice which is uniformly placed is visually detected under a constant background light source, so that the broken rice rate and brightness value of the sampled rice can be accurately detected, unstable artificial factors and environmental factors are eliminated, and calculation and control as accurate feedback data are facilitated.

Description

Technical Field

[0001] The present invention relates to the field of food processing, and in particular to an automatic control system and method for the brightness value of polished rice. Background Art

[0002] In traditional rice polishing, an elevator drops rice into a rotating polishing cylinder through a feed pipe, and the pressure door at the outlet of the rice polishing chamber is used for adjustment and control. If the polishing pressure is high, the collision movement is intense, and there will be more broken grains after polishing; if the polishing pressure is low, the collision movement is gentle, and there will be fewer broken grains after polishing, enabling the rice to be fully rubbed in the cylinder to remove the bran on the surface. At the same time, water is evenly sprayed in a certain proportion to gelatinize the starch on the surface of the rice grains, improving the brightness and taste of the rice.

[0003] Brightness refers to the degree of brightness. The calculation of brightness comes from the CIE (International Commission on Illumination) standard spectral luminance function, which is a key concept in color science. It describes the response of the human eye to light of different wavelengths, especially brightness (or luminance). The CIE 1931 chromaticity system defines the spectral luminance function of a standard observer, which is the basis for calculating color brightness and represents the relative luminance response of a standard observer to light of different wavelengths (380 nm to 780 nm).

[0004] In process control, a PID controller (also known as a PID regulator) that controls according to the proportional (P), integral (I), and derivative (D) of the deviation is one of the most widely used automatic controllers. It has the advantages of simple principle, easy implementation, wide application range, independent control parameters, and relatively simple selection of parameters.

[0005] After traditional rice is polished, it is necessary for workers to take rice and observe the brightness with the naked eye, and adjust the discharge pressure and water intake of the rice polishing machine according to the visual perception of the naked eye. However, the brightness of polished rice is affected by various factors such as environmental light sources and visual errors of different personnel, resulting in uneven brightness of the polished rice in different scenarios and by different workers, which affects the appearance and taste.

[0006] Traditional rice polishing mainly detects whiteness. However, the essence of polishing is to change the brightness value L by gelatinizing the surface starch, making the surface of the rice look crystal clear. At the same time, the color of the rice is determined during the growth process and cannot be changed by the polishing process. Some polishing machines combine visual detection, but there is a high-power motor inside the polishing machine, which will generate a large magnetic field and vibration, affecting the camera's photo detection. At the same time, it is difficult to achieve refined detection of the stacked rice, thus calculating accurate data.

[0007] The PID algorithm is only applicable to the usage environment of single variables. At the same time, for non-linear and time-varying systems, the performance of the PID control algorithm may be poor, the overshoot phenomenon is relatively obvious, and there are relatively large oscillations and stability problems. Summary of the Invention

[0008] The present invention is to solve the deficiencies of the above-mentioned existing technologies, and proposes an automatic control system and method for the brightness value of polished rice to solve the problems such as the inability to calculate accurate data mentioned in the background technology.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] An automatic control system for the brightness value of polished rice includes a rice polishing machine, a control integrated cabinet, a quality analyzer, and a sampling mechanism. Above the rice polishing machine is a raw material inlet, and below is an outlet. The outlet is connected to the inlet of a hoist through a chute pipe. The outlet of the hoist is connected to the sampling mechanism. The sampling mechanism is normally open and connected to the chute pipe of the next process. The sampling action state of the sampling mechanism is connected to the inlet of the quality analyzer. The outlet of the quality analyzer returns the material to the hoist and discharges it to the next process. In front of the upper part of the control integrated cabinet, a touch all-in-one machine is embedded after hollowing out.

[0011] As a further technical solution of the present invention: The rice polishing machine includes an atomizing nozzle, an electro-pneumatic proportional valve, a servo driver, a servo motor, and a pressure door. The control integrated cabinet includes a touch all-in-one machine and a PLC. The quality analyzer includes an analyzer host, a relay board, a background light, a vibrating feeder, a conveyor, and a vision camera. The sampling mechanism includes a solenoid valve, a cylinder, and a flap.

[0012] As a further technical solution of the present invention: The control integrated cabinet is internally equipped with a PLC. The PLC is configured with a PLC analog output module. One output of the PLC analog output module controls the output pressure of the electro-pneumatic proportional valve through analog quantity. The inlet end of the electro-pneumatic proportional valve is connected to the water inlet end of the water pipe, and the outlet end of the electro-pneumatic proportional valve is connected to the atomizing nozzle. The PLC controls the water pressure of the atomizing nozzle by adjusting the magnitude of the analog output current, thereby controlling the water volume sprayed by the atomizing nozzle. The other output of the PLC analog output module controls the discharge pressure door through a servo system. The servo driver of the servo system is set to the torque mode controlled by analog quantity current through parameter settings. The servo motor is connected and fixed to the pressure door at the outlet through a vertical shaft reducer and a coupling. The PLC controls the pressure of the pressure door by adjusting the magnitude of the analog output current.

[0013] As a further technical solution of the present invention: the PLC network port in the control integrated cabinet is connected to the network port of the analyzer host through a switch. The analyzer host controls the relay board, vibration feeder, conveyor and vision camera respectively through the 485 bus. The relay board controls the switches of the background light and the sampling mechanism solenoid valve through relays. The solenoid valve of the sampling mechanism controls the cylinder, and the air rod controls the flap action through the link mechanism. The PLC network port in the control integrated cabinet is connected to the touch all-in-one machine through a switch. The touch all-in-one machine collects PLC data through communication, collates and summarizes it through the database, and at the same time serves as a human-machine interaction interface for equipment control and parameter viewing.

[0014] As a further technical solution of the present invention: the touch all-in-one machine, as the upper computer of the PLC, is equipped with customized control software. The PLC collects the quality data detected by the quality analyzer in a cycle and the control data at the same time, and transmits them to the touch all-in-one machine in real time through the communication protocol.

[0015] As a further technical solution of the present invention: the touch all-in-one machine summarizes the data into a historical data report through the database and displays it on the touch all-in-one machine interface. The touch all-in-one machine interface is provided with a manual / automatic switching button and a switching interface for selecting manual adjustment or algorithm automatic adjustment.

[0016] As a further technical solution of the present invention: the PLC controls the quality analyzer and the rice polishing machine through communication control and switch control, and maps the control signal to the upper computer software of the touch all-in-one machine through communication.

[0017] An automatic control method for the brightness value of polished rice, using the above system, the specific method is as follows: The rice raw materials enter the rice polishing machine through the feeding port, and the polished rice is conveyed to the next process by the elevator. The quality analyzer controls the sampling mechanism, causing the flap of the sampling mechanism to rotate, allowing some rice to fall into the vibrating feeder of the quality analyzer. Subsequently, the flap of the sampling mechanism resets, and the vibrating feeder evenly shakes the sampled rice onto one end of the conveyor belt of the conveyor. During the conveying process of the flat-laid rice on the conveyor belt, the vision camera takes pictures under the standard light source of the background light. The rice at the other end of the conveyor belt is sent back to the material pipe and then back to the elevator, and then discharged to the next process. The rice detected by the vision camera in the quality analyzer is converted into an image signal and transmitted to the image processing system of the analyzer host. According to the pixel distribution, brightness, and color information, it is converted into a digital signal. The image processing system performs operations on these signals to extract the size features and color features of the target. The size feature is the broken rice situation of the rice, and the image obtained for the color feature is an RGB image. Each pixel consists of three components: red, green, and blue. Then, the brightness value L is calculated through RGB color. The quality analyzer samples and detects cyclically through the sampling mechanism. The analyzer host transmits the data of the detected broken rice rate and brightness value L to the PLC through the communication protocol. The staff sets the desired brightness value and broken rice rate for the PLC through the touch all-in-one machine, and sets the upper and lower limits of automatic regulation. The PLC controls the brightness value and broken rice rate, sets the target values of brightness and broken rice rate according to the type and quality of the rice. The difference between the brightness target value and the brightness value detected by the quality analyzer is used as the e(t) parameter of the self-tuning PID algorithm. The proportional coefficient Kp, integral coefficient Ki, and differential coefficient Kd are adjusted by the self-tuning system to output the value u(t). At the same time, the difference in the broken rice rate is used as a feedforward control to adjust the weight of the pressure door. Finally, the actual values of brightness and broken rice rate are obtained. At the same time, the brightness detection feedback value continues to be used as a closed-loop feedback to control the amount of water inlet, and the broken rice rate detection feedback value is used as a feedforward control to adjust the weight of the pressure door, indirectly affecting the brightness value and broken rice rate.

[0018] As a further technical solution of the present invention: The calculation formula for the brightness value L is:

[0019] L = (2.2 times)√[(R / 255)^2.2 + (1.5G / 255)^2.2 + (0.6B / 255)^2.2] / (1 + 1.5^2.2 + 0.6^2.2)].

[0020] As a further technical solution of the present invention: The PLC uses a feedforward control algorithm based on the self-tuning PID algorithm to control the brightness value and broken rice rate. The formula for the PID algorithm is:

[0021] u(t) = Kp*e(t) + Ki*∫e(t)dt + Kd*de(t) / dt

[0022] Among them, e(t) is the difference between the feedback signal and the desired signal, that is, the difference between the set brightness target value and the brightness value detected by the quality analyzer. ∫e(t)dt is the integral of e(t), and de(t) / dt is the derivative of e(t), which is automatically adjusted by the system self-tuning algorithm. u(t) is the output value, that is, the magnitude of the water intake.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] In this application, visually detecting evenly placed rice under a constant background light source can accurately measure the broken rice rate and brightness value of the sampled rice, eliminating unstable artificial and environmental factors, which is conducive to calculating and controlling as accurate feedback data.

[0025] This application can accurately represent the polishing effect of rice through the detected brightness of the rice, and thus ensure the stability of the rice quality through algorithm control.

[0026] The feedforward PID control algorithm of this application calculates a control quantity by comparing the difference between the target value and the actual value, and then outputs it to the controlled object for control. Feedforward control can reduce the overshoot of the system, reduce the response time, and make the system more stable.

[0027] Placing the quality analyzer and the rice polishing machine separately in this application can effectively reduce the electromagnetic interference and vibration impact of the high-power motor on the quality analyzer.

[0028] The touch all-in-one machine of this application can be placed in the control room through an extended cable. As a human-machine interface, the touch all-in-one machine can facilitate the staff to operate the rice polishing machine and the quality analyzer and view real-time and historical data. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the present invention;

[0030] Figure 2 is a schematic system diagram of the present invention;

[0031] Figure 3 is an architecture diagram of the control algorithm of the present invention.

[0032] In the figure: 1 - raw material inlet, 2 - elevator, 3 - sampling mechanism, 4 - rice polishing machine, 5 - outlet, 6 - control cabinet, 7 - quality analyzer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] As Figures 1-3 shown, the present invention discloses an automatic control system for the brightness value of polished rice. The system consists of a control integrated cabinet 6, a quality analyzer 7, a rice polishing machine 4, an elevator 2, and a sampling mechanism 3. Above the rice polishing machine 4 is the raw material inlet, and below is the outlet. The outlet is connected to the inlet of the elevator 2 through a chute. The outlet of the elevator 2 is connected to the sampling mechanism 3. The sampling mechanism 3 is normally open and connected to the chute of the next process. The sampling action state of the sampling mechanism 3 is connected to the inlet of the quality analyzer 7. The outlet of the quality analyzer 7 returns the material to the elevator 2 and discharges it to the next process.

[0035] In the upper front of the control integrated cabinet 6, a touch all-in-one machine is embedded with a hollowed-out area. Inside the control integrated cabinet 6, there is a PLC. The PLC is configured with a PLC analog output module. One output of the PLC analog output module controls the output pressure of the electric proportional valve through an analog quantity. The inlet end of the electric proportional valve is connected to the water inlet end of the water pipe, and the outlet end of the electric proportional valve is connected to the atomizing nozzle. The PLC controls the water pressure of the atomizing nozzle by adjusting the magnitude of the analog output current, thereby controlling the water volume sprayed by the atomizing nozzle. Another output of the PLC analog output module controls the discharge pressure door through a servo system. The servo driver of the servo system is set to the torque mode controlled by an analog current through parameters. The servo motor is connected and fixed to the pressure door at the outlet through a vertical shaft reducer and a coupling. The PLC controls the pressure of the pressure door by adjusting the magnitude of the analog output current.

[0036] The PLC network port in the control integrated cabinet 6 is connected to the network port of the analyzer host through a switch. The analyzer host controls a relay board, a vibrating feeder, a conveyor, and a vision camera respectively through a 485 bus. The relay board controls the on / off of the background light and the sampling mechanism solenoid valve through a relay. The solenoid valve of the sampling mechanism controls the cylinder, and the air rod controls the flap action through a linkage mechanism.

[0037] The PLC network port in the control integrated cabinet 6 is connected to the touch all-in-one machine through a switch. The touch all-in-one machine collects PLC data through communication, collates and summarizes it through a database, and at the same time serves as a human-machine interface to facilitate the staff to control the equipment and view parameters.

[0038] The working principle is as follows:

[0039] During the production process, rice raw materials enter the rice polisher through the feed inlet. After polishing, the rice is conveyed to the next process by the elevator. The quality analyzer controls the sampling mechanism, causing the flap of the sampling mechanism to rotate, allowing some rice to fall into the vibrating feeder of the quality analyzer, and then the flap of the sampling mechanism resets. The vibrating feeder evenly shakes the sampled rice onto one end of the conveyor belt of the conveyor. During the conveying process of the evenly spread rice on the conveyor belt, the vision camera takes pictures under the standard light source of the background light. The rice at the other end of the conveyor belt is sent back to the feed pipe and then back to the elevator, and then discharged to the next process.

[0040] In the quality analyzer, the rice detected by the vision camera is converted into an image signal and transmitted to the image processing system of the analyzer host. According to information such as pixel distribution, brightness, and color, it is converted into a digital signal. The image processing system performs operations on these signals to extract the size features and color features of the target. The size feature is the broken rice situation of the rice, and the image obtained for the color feature is an RGB image. Each pixel consists of three components: red (R), green (G), and blue (B). Then, the brightness L is calculated through RGB color.

[0041] RGB brightness L calculation formula:

[0042] L = (2.2nd root) √[(R / 255)^2.2+(1.5G / 255)^2.2+(0.6B / 255)^2.2] / (1 + 1.5^2.2+0.6^2.2)

[0043] The quality analyzer samples and detects cyclically through the sampling mechanism. The analyzer host transmits the data of the detected broken rice rate and brightness value L to the PLC through the communication protocol. The staff sets the desired brightness value and broken rice rate to the PLC through the touch all-in-one machine, and sets the upper and lower limits of automatic regulation. The PLC uses a feedforward control algorithm based on the self-tuning PID algorithm to control the brightness value and broken rice rate.

[0044] PID algorithm formula: u(t) = Kp*e(t)+Ki*∫e(t)dt+Kd*de(t) / dt

[0045] Among them, e(t) is the difference between the feedback signal and the desired signal, that is, the difference between the set brightness target value and the brightness value detected by the quality analyzer.

[0046] ∫e(t)dt is the integral of e(t).

[0047] de(t) / dt is the differential of e(t).

[0048] Kp, Ki, and Kd are the proportional, integral, and differential coefficients, which are automatically adjusted by the system self-tuning algorithm.

[0049] u(t) is the output value, i.e., the magnitude of the water inflow.

[0050] Based on the type and quality of rice, the target values of brightness and broken rice rate are set. The difference between the target value of brightness and the brightness value detected by the quality analyzer is used as the e(t) parameter of the self-tuning PID algorithm. Kp, Ki, and Kd adjust the output value u(t) through the self-tuning system. At the same time, the difference in broken rice rate is used as feedforward control to adjust the weight of the pressure door. Finally, the actual values of brightness and broken rice rate are obtained. Meanwhile, the brightness detection feedback value continues to be used as closed-loop feedback control for the magnitude of the water inflow, and the broken rice rate detection feedback value is used as feedforward control for the weight of the pressure door, indirectly affecting the brightness value and the broken rice rate.

[0051] The touch all-in-one computer, as the upper computer of the PLC, is equipped with customized control software. The PLC collects the quality data cyclically detected by the quality analyzer and the control data at the same time, and transmits them to the touch all-in-one computer in real time through the communication protocol. The touch all-in-one computer summarizes them into a historical data report through the database and displays it on the interface of the touch all-in-one computer. There are manual-automatic switching buttons and switching interfaces on the interface of the touch all-in-one computer for selecting manual adjustment or algorithm automatic adjustment.

[0052] The PLC controls the quality analyzer and the rice polishing machine through communication control and switch control, and maps the control signals to the upper computer software of the touch all-in-one computer through communication. Staff can operate the quality analyzer and the rice polishing machine through the touch all-in-one computer.

[0053] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0054] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only includes an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A rice polishing brightness value automatic control system, comprising a rice polishing machine, a control integrated cabinet, a quality analyzer and a sampling mechanism, characterized in that: The rice polisher has a raw material feed port at the top and a discharge port at the bottom. The discharge port is connected to the feed port of the elevator through a slide pipe. The discharge port of the elevator is connected to a sampling mechanism. The sampling mechanism is connected to the slide pipe of the next process in a normally open state. The sampling mechanism is connected to the feed port of the quality analyzer in a sampling action state. The discharge port of the quality analyzer returns the material to the elevator and discharges the material to the next process. The top front of the control integrated cabinet is hollowed out to embed a touch integrated machine.

2. A rice polishing lightness value automatic control system according to claim 1, characterized in that, The rice polisher includes an atomizing nozzle, an electric proportional valve, a servo driver, a servo motor and a pressure door; the control integrated cabinet includes a touch integrated machine and a PLC; the quality analyzer includes an analyzer host, a relay board, a background light, a vibration feeder, a conveyor and a visual camera; and the sampling mechanism includes an electromagnetic valve, a cylinder and a flap.

3. A rice polishing lightness value automatic control system according to claim 2, characterized in that, The control integrated cabinet is equipped with a PLC, and the PLC is equipped with a PLC analog output module. One output of the PLC analog output module controls the output pressure of the electrical proportional valve through analog quantity. The inlet end of the electrical proportional valve is connected to the water inlet end of the water pipe, and the outlet end of the electrical proportional valve is connected to the atomizing nozzle. The PLC controls the water pressure of the electrical proportional valve by adjusting the size of the analog output current, thereby controlling the amount of water sprayed by the atomizing nozzle. Another output of the PLC analog output module controls the discharge pressure gate through the servo system. The servo driver of the servo system is set to a torque mode controlled by analog current through parameters. The servo motor is connected to the pressure gate fixed to the discharge port through a vertical axis reducer and a coupling. The PLC controls the pressure of the pressure gate by adjusting the size of the analog output current.

4. A rice polishing lightness value automatic control system according to claim 3, characterized in that, The PLC network port in the control cabinet is connected to the network port of the analyzer host through the switch. The analyzer host controls the relay board, the vibrating feeder, the conveyor and the visual camera respectively through the 485 bus. The relay board controls the switch of the background light and the solenoid valve of the sampling mechanism through the relay. The solenoid valve of the sampling mechanism controls the cylinder. The gas rod controls the flip plate action through the connecting rod mechanism. The PLC network port in the control cabinet is connected to the touch all-in-one machine through the switch. The touch all-in-one machine collects PLC data through communication, organizes and summarizes it through the database, and serves as a human-computer interaction interface for equipment control and parameter viewing.

5. A rice polishing lightness value automatic control system according to claim 4, characterized in that, The touch-control integrated machine is installed with customized control software as the upper computer of the PLC. The PLC collects the quality data detected cyclically by the quality analyzer and the control data at the same time, and transmits them to the touch-control integrated machine in real time through the communication protocol.

6. A rice polishing lightness value automatic control system according to claim 5, characterized in that, The touch-screen integrated machine summarizes the historical data through the database into a report form and displays it on the touch-screen integrated machine interface. The touch-screen integrated machine interface is provided with a manual-automatic switching button and a switching interface for selecting manual adjustment or automatic adjustment by algorithm.

7. A rice polishing lightness value automatic control system according to claim 6, characterized in that: The PLC controls the quality analyzer and the rice polisher through communication control and switches, and maps the control signal to the upper computer software of the touch-control integrated machine through communication.

8. A rice polishing brightness value automatic control method, characterized in that: The system described in any one of claims 1 to 7 is adopted, and the specific method is as follows: the rice raw material enters the rice polishing machine from the feed inlet, and the polished rice is transported to the next process by the elevator. The quality analyzer controls the sampling mechanism to rotate the flap of the sampling mechanism to allow part of the rice to fall into the vibrating feeder of the quality analyzer. Then the flap of the sampling mechanism is reset, and the vibrating feeder evenly shakes the sampled rice to one end of the conveyor belt of the conveyor. During the conveying process of the flat rice by the conveyor belt, the visual camera takes pictures under the standard light source of the background lamp, and the other end of the conveyor belt returns the rice to the material pipe and returns to the elevator, and then discharges it to the next process. The rice detected by the visual camera in the quality analyzer is converted into an image signal and transmitted to the image processing system of the analyzer host. According to the pixel distribution, brightness and color information, it is converted into a digital signal. The image processing system calculates these signals to extract the size characteristics and color characteristics of the target. The size characteristic is the broken rice situation of the rice, and the image obtained by the color characteristic is an RGB image. Each image The color element is composed of three components: red, green and blue. The lightness value L is calculated through RGB color. The quality analyzer samples and detects cyclically through the sampling mechanism. The analyzer host transmits the detected broken rice rate and lightness value L data to the PLC through the communication protocol. The staff sets the desired lightness value and broken rice rate to the PLC through the touch all-in-one machine, and sets the upper and lower limits of automatic control. The PLC controls the lightness value and broken rice rate. The lightness and broken rice rate target values ​​are set according to the type and quality of rice. The difference between the lightness target value and the lightness value detected by the quality analyzer is used as the e(t) parameter of the self-tuning PID algorithm. The proportional coefficient Kp, the integral coefficient Ki and the differential coefficient Kd are used to adjust the output value u(t) through the self-tuning system. At the same time, the difference in the broken rice rate is used as a feedforward control to adjust the weight of the pressure gate, and finally the actual values ​​of the lightness and broken rice rate are obtained. At the same time, the lightness detection feedback value continues to be used as a closed-loop feedback to control the amount of water inlet, and the broken rice rate detection feedback value is used as a feedforward to control the weight of the pressure gate, which indirectly affects the lightness value and broken rice rate.

9. A rice polishing lightness value automatic control method according to claim 8, characterized in that, The calculation formula of the lightness value L is: L = (2.2 times)√[(R / 255)^2.2+(1.5G / 255)^2.2+(0.6B / 255)^2.2] / (1+1.5^2.2+0.6^2.2)].

10. A rice polishing brightness value automatic control method according to claim 8, characterized in that: The PLC uses a feedforward control algorithm based on a self-tuning PID algorithm to control the brightness value and broken rice rate. The formula of the PID algorithm is: u(t)=Kp*e(t)+Ki*∫e(t)dt+Kd*de(t) / dt Among them, e(t) is the difference between the feedback signal and the expected signal, that is, the difference between the set brightness target value and the brightness value detected by the quality analyzer, ∫e(t)dt is the integral of e(t), de(t) / dt is the differential of e(t), which is automatically adjusted by the system self-tuning algorithm, and u(t) is the output value, that is, the amount of water inlet.

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