阅读说明：本技术 一种谷物含水率在线检测方法及系统 (Grain water content online detection method and system ) 是由 刘政 金诚谦 李泽峰 杨腾祥 于 2019-11-27 设计创作，主要内容包括：一种谷物含水率在线检测方法及系统,该方法包括以下步骤：设置谷物紧实度阈值Pm；采用温度传感器和谷物紧实度传感器检测极板电容器内所容纳的谷物温度T和紧实度P,并将检测信号输出至MCU处理器；当实时谷物紧实度P超过谷物紧实度阈值Pm时,启动多谐振荡器获取方波频率F,输出至MCU处理器；启动电机驱动搅龙将电容器内所容纳的谷物移除；获取实时的谷物含水率Hr。本发明提供谷物含水率在线检测方法及系统,该方法能够快速经济的完成谷物含水率的检测,同时,检测精度相较于传统电容法也大幅提升。(An online detection method and system for grain moisture content are provided, the method comprises the following steps: setting a grain compactness threshold value Pm; detecting the temperature T and the compactness P of grains contained in the polar plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting a detection signal to an MCU processor; when the real-time grain compactness P exceeds a grain compactness threshold Pm, starting a multivibrator to obtain a square wave frequency F, and outputting the square wave frequency F to an MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor; and acquiring the real-time water content Hr of the grains. The invention provides an online detection method and system for the moisture content of grains, the method can quickly and economically finish the detection of the moisture content of grains, and meanwhile, the detection precision is greatly improved compared with that of a traditional capacitance method.)

1. An online detection method for the moisture content of grains is characterized by comprising the following steps:

s1, setting a grain compactness threshold value Pm;

s2, detecting the temperature T and the compactness P of the grains contained in the plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting detection signals to an MCU processor;

s3, when the real-time grain compactness P exceeds the grain compactness threshold Pm set in the step S1, starting a multivibrator to obtain a square wave frequency F, and outputting the square wave frequency F to the MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor;

and S4, acquiring the real-time water content Hr of the grains.

2. The method for detecting the moisture content of grain according to claim 1, wherein in step S4: when the grain to be detected is rice, the water content Hr of the rice adopts the following formula:

Hr＝-513.2940+0.0014T³-0.3332T²+24.8893T+0.0001F³-0.1618F²+17.8358F+0.0041T²F+0.0038TF²-0.6164TF，

when the grain to be detected is wheat, the water content Hr' of the wheat adopts the following formula:

Hr’＝-0.68122F-0.13344T+55.41621。

3. the method as claimed in claim 1, wherein the square wave frequency F is a code value of the signal frequency integrated with 500.

4. The on-line detection method of the water content of the grains according to claim 1, wherein the plate capacitor is composed of two identical parallel copper-clad plates.

5. The on-line detection method for the water content of grains according to claim 1, wherein the effective facing area of the two copper-clad plates is 2500-3500mm²The thickness is 1.5-1.7 mm.

6. The method for on-line detection of water content of cereal as claimed in claim 5, wherein effective facing area of two copper-clad plates is 2996mm²The thickness was 1.6 mm.

7. An apparatus for on-line detecting moisture content of grain according to any one of claims 1 to 6, comprising: sensor unit, polar plate condenser, frequency detection circuit and MCU treater, the polar plate condenser is used for holding the cereal that awaits measuring, and the signal input part that frequency detection circuit was connected to the polar plate condenser links to each other, and the sensor unit includes temperature sensor and cereal degree of packing sensor for real-time temperature and the cereal degree of packing that awaits measuring that hold in the detection polar plate condenser, the frequency output of aforementioned frequency detection circuit and the signal output of sensor unit all link to each other with MCU treater's corresponding signal input part.

8. The on-line detector for the moisture content of grains as claimed in claim 7, wherein said frequency detection circuit comprises a multivibrator, a capacitor C8, and resistors R2 and R3, a pin CVolt of said multivibrator is connected to ground after being connected to a filter capacitor C8, a resistor R2 is connected between a pin R and a pin DIS of said multivibrator, a resistor R3 is connected between a pin THR and a pin DIS, and a connection point between a pin THR and a resistor R3 of said multivibrator is connected to a terminal J1, said terminal is used for being connected to one plate of a plate capacitor, and the other plate of said plate capacitor is connected to ground through a connection terminal J2.

9. The apparatus as claimed in claim 8, wherein the multivibrator includes an RS trigger and a discharge switch.

10. The utility model provides a cereal moisture content on-line measuring system which characterized in that, this system includes:

the threshold setting module is used for setting a grain compactness threshold Pm;

a parameter acquisition module: detecting the temperature T and the compactness P of grains contained in the polar plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting a detection signal to an MCU processor;

a frequency acquisition module: when the real-time grain compactness P exceeds the grain compactness threshold Pm set in the step S1, starting a multivibrator to obtain square wave frequency F, and outputting the square wave frequency F to an MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor;

the water content obtaining module: and acquiring the real-time water content Hr of the grains.

Technical Field

The invention relates to the field of intelligent agriculture, in particular to a method for detecting the moisture content of grains harvested by a harvester, and more particularly relates to an online detection device and a sampling mechanism for the moisture content of grains of a combine harvester.

Background

At present, the detection methods of the water content of the grains are various, and mainly include a capacitance method, a resistance method, a Karfeihui method, a nuclear magnetic resonance method, a microwave method, an acoustic method, an infrared ray method, an electric oven method and the like. At present, in real-time detection of grain moisture, a capacitance method and a resistance method are most widely applied but detection precision is generally low, an electric oven method is mainly used for laboratory grain drying and moisture content calibration, and other methods are less applied due to complex structure or high price.

Disclosure of Invention

In order to solve the problems of low precision and low accuracy of measuring the moisture content of the grains by a capacitance method, the invention provides the online detection method and the online detection system for the moisture content of the grains.

The technical scheme of the invention is as follows:

the invention provides an online detection method for grain water content, which comprises the following steps: s1, setting a grain compactness threshold value Pm;

s2, detecting the temperature T and the compactness P of the grains contained in the plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting detection signals to an MCU processor;

s3, when the real-time grain compactness P exceeds the grain compactness threshold Pm set in the step S1, starting a multivibrator to obtain a square wave frequency F, and outputting the square wave frequency F to the MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor;

and S4, acquiring the real-time water content Hr of the grains.

Further, in step S4:

when the grain to be detected is rice, the water content Hr of the rice adopts the following formula:

Hr＝-513.2940+0.0014T³-0.3332T²+24.8893T+0.0001F³-0.1618F²+

17.8358F+0.0041T²F+0.0038TF²-0.6164TF，

when the grain to be detected is wheat, the water content Hr' of the wheat adopts the following formula:

Hr’＝-0.68122F-0.13344T+55.41621。

further, the square wave frequency F is the encoded value of the signal frequency rounded to 500.

Further, the plate capacitor is composed of two identical parallel copper clad plates.

Further, the effective facing area of the two copper-clad plates is 2500-3500mm²The thickness is 1.5-1.7 mm.

Further, the effective facing area of the two copper-clad plates is 2996mm²The thickness was 1.6 mm.

A device adopted by an online grain water content detection method comprises the following steps: sensor unit, polar plate condenser, frequency detection circuit and MCU treater, the polar plate condenser is used for holding the cereal that awaits measuring, and the signal input part that frequency detection circuit was connected to the polar plate condenser links to each other, and the sensor unit includes temperature sensor and cereal degree of packing sensor for real-time temperature and the cereal degree of packing that awaits measuring that hold in the detection polar plate condenser, the frequency output of aforementioned frequency detection circuit and the signal output of sensor unit all link to each other with MCU treater's corresponding signal input part.

Furthermore, the frequency detection circuit comprises a multivibrator, a capacitor C8, and resistors R2 and R3, wherein a pin CVolt of the multivibrator is grounded after being connected with a filter capacitor C8, a resistor R2 is connected between the pin R and the pin DIS of the multivibrator in parallel, a resistor R3 is connected between the pin THR and the pin DIS in parallel, a connection point between the pin THR and the resistor R3 of the multivibrator is connected with a terminal J1, the terminal is used for being connected with one plate of a plate capacitor, and the other plate of the plate capacitor is grounded through a connection terminal J2.

Further, the multivibrator includes an RS flip-flop and a discharge switch.

An on-line detection system for the moisture content of grains, which comprises:

the threshold setting module is used for setting a grain compactness threshold Pm;

a parameter acquisition module: detecting the temperature T and the compactness P of grains contained in the polar plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting a detection signal to an MCU processor;

a frequency acquisition module: when the real-time grain compactness P exceeds the grain compactness threshold Pm set in the step S1, starting a multivibrator to obtain square wave frequency F, and outputting the square wave frequency F to an MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor;

the water content obtaining module: and acquiring the real-time water content Hr of the grains.

The invention has the beneficial effects that:

the invention provides an enhanced capacitive grain water content detection method, which aims to solve the problems of low precision and low accuracy of grain water content measurement by a capacitance method. The method is an online detection method for the moisture content of the grains based on frequency characteristic response, can quickly and economically finish detection of the moisture content of the grains, and meanwhile, compared with a traditional capacitance method, the detection precision is greatly improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.

Fig. 1 shows a schematic block diagram of the present invention.

Fig. 2 shows a schematic diagram of a frequency detection circuit.

FIG. 3 shows a water cut fit effect graph.

Fig. 4 shows a water cut detection verification effect diagram.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein.

The invention provides an online detection method for grain water content, which comprises the following steps: s1, setting a grain compactness threshold value Pm;

s2, detecting the temperature T and the compactness P of the grains contained in the plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting detection signals to an MCU processor;

s3, when the real-time grain compactness P exceeds the grain compactness threshold Pm set in the step S1, starting a multivibrator to obtain a square wave frequency F, and outputting the square wave frequency F to the MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor;

s4, acquiring the real-time water content Hr of the grains;

when the grain to be detected is rice, the water content Hr of the rice adopts the following formula:

Hr＝-513.2940+0.0014T³-0.3332T²+24.8893T+0.0001F³-0.1618F²+

17.8358F+0.0041T²F+0.0038TF²-0.6164TF，

when the grain to be detected is wheat, the water content Hr' of the wheat adopts the following formula:

Hr’＝-0.68122F-0.13344T+55.41621。

the square wave frequency F is the code value of the signal frequency rounded by 500.

Further, the plate capacitor is composed of two identical parallel copper-clad plates; effective facing area of two copper-clad plates is 2500-²Preferably 2996mm²(ii) a The thickness is 1.5-1.7mm, preferably 1.6 mm.

As shown in fig. 1, a device adopted by an online grain moisture content detection method comprises: sensor unit, polar plate condenser, frequency detection circuit and MCU treater, the polar plate condenser is used for holding the cereal that awaits measuring, and the signal input part that frequency detection circuit was connected to the polar plate condenser links to each other, and the sensor unit includes temperature sensor and cereal degree of packing sensor for real-time temperature and the cereal degree of packing that awaits measuring that hold in the detection polar plate condenser, the frequency output of aforementioned frequency detection circuit and the signal output of sensor unit all link to each other with MCU treater's corresponding signal input part.

Furthermore, the frequency detection circuit comprises a multivibrator, a capacitor C8, and resistors R2 and R3, wherein a pin CVolt of the multivibrator is grounded after being connected with a filter capacitor C8, a resistor R2 is connected between the pin R and the pin DIS of the multivibrator in parallel, a resistor R3 is connected between the pin THR and the pin DIS in parallel, a connection point between the pin THR and the resistor R3 of the multivibrator is connected with a terminal J1, the terminal is used for being connected with one plate of a plate capacitor, and the other plate of the plate capacitor is grounded through a connection terminal J2; the multivibrator includes an RS flip-flop and a discharge switch.

An on-line detection system for the moisture content of grains, which comprises:

the threshold setting module is used for setting a grain compactness threshold Pm;

a parameter acquisition module: detecting the temperature T and the compactness P of grains contained in the polar plate capacitor by adopting a temperature sensor and a grain compactness sensor, and outputting a detection signal to an MCU processor;

a frequency acquisition module: when the real-time grain compactness P exceeds the grain compactness threshold Pm set in the step S1, starting a multivibrator to obtain square wave frequency F, and outputting the square wave frequency F to an MCU processor; starting a motor to drive an auger to remove the grains contained in the capacitor;

the water content obtaining module: and acquiring the real-time water content Hr of the grains.