Moisture Measurement System

Abstract

To provide a moisture content measuring system capable of accurately measuring moisture content contained in grains.SOLUTION: When a crop to be a measurement object of moisture content is set to rice or wheat, a first measuring method is selected as a measuring method measuring moisture content of grains, and operation of the moisture sensor is controlled according to a second measuring method. On the other hand, when the crop to be a measurement object of moisture content is set to barley, the second measuring method is selected as a measuring method for measuring moisture content of grains, and operation of the moisture sensor is controlled according to the second measuring method.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a moisture measurement system for measuring the moisture content of grains. [Background technology]

[0002] In a combine harvester, crops planted in a field are harvested by a harvesting device, and the harvested crops are transported from the harvesting device to a thresher, where the grains are removed from the crop stalks, sorted, and transported to a grain tank.

[0003] Some combine harvesters are provided with a moisture sensor (moisture meter) in the grain tank that measures the amount of moisture contained in grains. The moisture sensor is disposed in a position where it can receive grains discharged from the discharge section. The moisture sensor is, for example, an electrical resistance type moisture sensor, and is provided with a pair of electrode rollers. Grains received in the moisture sensor are caught between the pair of electrode rollers as the pair of rollers rotate, and are crushed between the electrode rollers. With the crushed grains sandwiched between the electrode rollers, the electrical resistance between the electrode rollers is measured, and the amount of moisture contained in the grains is determined from the electrical resistance value (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6451513 Summary of the Invention [Problem to be solved by the invention]

[0005] However, a configuration using an electrical resistance type moisture sensor has the problem that the moisture amount measurement accuracy is low.

[0006] An object of the present invention is to provide a moisture content measuring system capable of measuring the moisture content in grains with high accuracy. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a moisture measurement system according to one aspect of the present invention includes a moisture sensor that crushes grains between a pair of electrode rollers by rotating the electrode rollers and outputs a signal corresponding to the electrical resistance value between the electrode rollers when the grains are crushed, and a control device that controls the operation of the moisture sensor, receives the signal output from the moisture sensor, determines a sensor output value from the received signal, and determines the moisture content corresponding to the sensor output value from a calibration curve, and the control device switches between a plurality of control methods for controlling the operation of the moisture sensor depending on the type of grain set as the target for moisture measurement.

[0008] According to this configuration, in the moisture sensor, grains are crushed between a pair of electrode rollers by rotation of the electrode rollers. Then, with the crushed grains (crushed grains) sandwiched between the electrode rollers, the moisture sensor outputs a signal corresponding to the electrical resistance between the electrode rollers to the control device. The control device determines a sensor output value from the signal received from the moisture sensor, and determines the moisture content corresponding to the sensor output value from the calibration curve.

[0009] Depending on the type of grain, it is difficult for the grain to enter between the electrode rollers. For example, barley is more difficult to enter between the electrode rollers than rice or wheat. When a grain that is difficult to enter between the electrode rollers is set as a target for moisture content measurement, a period in which the value of the signal output from the moisture sensor is extremely small may occur during the measurement period in which the electrode rollers are rotating because the grain does not enter between the electrode rollers. Therefore, in a configuration in which a sensor output value is calculated from the value of the signal output from the moisture sensor during the measurement period and the moisture content corresponding to the sensor output value is calculated from a calibration curve, the moisture content contained in the grain cannot be measured with high accuracy.

[0010] Therefore, depending on the type of grain set as the target for moisture content measurement, a method for controlling the operation of the moisture sensor is switched among a plurality of control methods, and the operation of the moisture sensor is controlled by the control method according to the type of grain. As a result, a signal from which a sensor output value according to the type of grain can be obtained is output from the moisture sensor. Therefore, the control device can obtain a sensor output value according to the type of grain, and can obtain the moisture content corresponding to the sensor output. Therefore, the moisture content in the grain can be measured with high accuracy.

[0011] The moisture content measuring system further includes an operating device that is operated to set the information, and the type of grain may be set by operating the operating device.

[0012] In this configuration, the person operating the operation device can set the type of grain.

[0013] The system further includes a working device that performs work for harvesting grains, and the type of grain that is to be the target of work by the working device is set by operating the operating device, and the control device may switch between a plurality of control methods for controlling the operation of the moisture sensor depending on the type of grain that is set as the target of work by the working device.

[0014] In this configuration, there is no need to set the target for moisture measurement.

[0015] The working device may be a threshing device that sorts and collects the sorting objects obtained by threshing a crop.

[0016] In a threshing machine, for example, the opening degree of the chaff sieve is changed according to the type of grain to be threshed. Therefore, the threshing machine needs to set the type of grain to be threshed. By setting this as the target of moisture measurement, it becomes unnecessary to set the target of moisture measurement.

[0017] A moisture measurement system according to another aspect of the present invention includes a moisture sensor that crushes grains between a pair of electrode rollers by rotating the electrode rollers and outputs a signal corresponding to the electrical resistance value between the electrode rollers when the grains are crushed, and a control device that controls the operation of the moisture sensor, receives the signal output from the moisture sensor, determines a sensor output value from the received signal, and determines the moisture content corresponding to the sensor output value from a calibration curve, and the control device switches between a plurality of control methods for controlling the operation of the moisture sensor depending on the size of the grains set as the targets for moisture measurement.

[0018] According to this configuration, in the moisture sensor, grains are crushed between a pair of electrode rollers by rotation of the electrode rollers. Then, with the crushed grains (crushed grains) sandwiched between the electrode rollers, the moisture sensor outputs a signal corresponding to the electrical resistance between the electrode rollers to the control device. The control device determines a sensor output value from the signal received from the moisture sensor, and determines the moisture content corresponding to the sensor output value from the calibration curve.

[0019] Depending on the size of the grain, it is difficult for the grain to enter between the electrode rollers. For example, large grains such as barley are more difficult to enter between the electrode rollers than small grains such as rice and wheat. When a grain that is difficult to enter between the electrode rollers is set as a target for moisture content measurement, a period in which the value of the signal output from the moisture sensor is extremely small may occur during the measurement period in which the electrode rollers are rotating because the grain does not enter between the electrode rollers. Therefore, in a configuration in which a sensor output value is calculated from the value of the signal output from the moisture sensor during the measurement period and the moisture content corresponding to the sensor output value is calculated from a calibration curve, the moisture content contained in the grain cannot be measured with high accuracy.

[0020] Therefore, the method of controlling the operation of the moisture sensor is switched among a plurality of control methods depending on the size of the grain set as the target for moisture measurement, and the operation of the moisture sensor is controlled by the control method according to the type of grain. This makes it possible to obtain a sensor output value according to the size of the grain from the output signal of the moisture sensor, and to obtain the moisture content corresponding to the sensor output. Therefore, the moisture content in the grain can be measured with high accuracy.

[0021] The multiple control methods may include a first control method that sets a relatively long long period and controls the operation of the moisture sensor so that a signal is output from the moisture sensor during that long period, and a second control method that sets relatively short short periods repeatedly with time intervals between periods and controls the operation of the moisture sensor so that a signal is output from the moisture sensor during each short period.

[0022] The moisture measurement system further includes an input device for inputting a reference moisture content of the grain to the control device, the reference moisture content being a measured value of the moisture content of the grain estimated to have the same moisture content as the grain crushed by the moisture sensor, measured by an instrument other than the control device, and the control device may obtain a value corresponding to the reference moisture content from the calibration curve, and may correct the sensor output value using the correction value, taking the deviation between the obtained value and the sensor output value as a correction value.

[0023] According to this configuration, the moisture content of the kernels can be measured with higher accuracy. Effect of the Invention

[0024] According to the present invention, the moisture content of grains can be measured with high accuracy. [Brief description of the drawings]

[0025] [Figure 1] 1 is a right side view of a combine harvester in which a moisture content measuring device according to one embodiment of the present invention is mounted. [Diagram 2] FIG. 2 is a perspective view of the upper left portion of the grain tank from the rear right, with the top plate of the grain tank removed. [Diagram 3] FIG. 2 is a front view of the grain tank. [Figure 4] FIG. 2 is a front view of the grain tank with the cover removed; [Diagram 5] FIG. 13 is a rear view of the moisture sensor. [Figure 6] FIG. 2 is a block diagram showing a main part of the electrical configuration of the combine harvester. [Figure 7] 13 is a flowchart showing the flow of a measurement method selection process. [Figure 8] FIG. 1 is a diagram showing the contents of a first measurement method. [Figure 9] FIG. 11 is a diagram showing the contents of a second measurement method. [Figure 10] 11 is a diagram for explaining a method of correcting a sensor output value. FIG. [Figure 11] FIG. 13 is a block diagram showing a modified example of the electrical configuration of the combine harvester. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0027] <Overall configuration of combine harvester> FIG. 1 is a right side view of a combine harvester 1 on which a moisture content measuring device according to one embodiment of the present invention is mounted.

[0028] The combine harvester 1 is an agricultural machine that harvests and threshes crops while traveling in a field.

[0029] The combine harvester 1 employs a pair of left and right crawler traveling devices 2 as traveling devices capable of traveling over rough ground such as farm fields. A machine body frame 3 is supported by the left and right crawler traveling devices 2, and power from an engine provided on the machine body frame 3 is transmitted to the crawler traveling devices 2 via a transmission.

[0030] In addition, a cabin 4, a threshing device 5, and a grain tank 6 are provided on the machine frame 3. In front of the crawler traveling device 2 and the machine frame 3, a reaping device 7 that harvests crops is provided.

[0031] The cabin 4 is disposed on the front end of the aircraft frame 3. The cabin 4 provides a space for a user to board inside, and within the space, for example, a driver's seat where the user sits, operation levers operated by the user, etc. are disposed. An openable door 8 is provided on the right side of the cabin 4, and the user can enter the cabin 4 by opening the door 8.

[0032] The threshing device 5 is located to the left rear of the cabin 4. The grain tank 6 is located behind the cabin 4 and to the right of the threshing device 5. In the threshing device 5, the materials to be sorted obtained by threshing the crop are sorted and collected. The collected materials to be sorted (grains) are transported to the grain tank 6 and stored in the grain tank 6. An unloader 9 is connected to the grain tank 6, and the grains stored in the grain tank 6 can be discharged from the grain tank 6 to the outside of the machine by the unloader 9.

[0033] <Main components of the grain tank> FIG. 2 is a perspective view of the upper left portion of the inside of the grain tank 6 as seen from the right rear, with the top plate of the grain tank 6 removed.

[0034] A discharge section 12 is provided in the grain tank 6 at the center in the front-to-rear direction at the top of the left side wall 11 of the grain tank 6. Although not shown, the discharge section 12 is provided with a rotating blade that rotates about an axis that extends in the vertical direction. The grains are transported from the threshing device 5 to the discharge section 12, swept away by the rotating rotating blade, and thrown out of the discharge section 12 toward the right front.

[0035] A sensor housing portion 14 that bulges into the grain tank 6 is formed on the front wall 13 of the grain tank 6. A moisture sensor 15 is housed in the sensor housing portion 14.

[0036] 3 and 4 are front views of the grain tank 6. FIG.

[0037] 4, the sensor accommodating section 14 includes an upper inclined plate 16 inclined rearward and downward from the upper end of the front wall 13, a rear plate 17 extending downward from the rear edge of the upper inclined plate 16, a lower inclined plate 18 inclined frontward and downward from the lower edge of the rear plate 17 toward the lower end of the front wall 13, and side plates 19 provided to close the space surrounded by the upper inclined plate 16, the rear plate 17, and the lower inclined plate 18 from the left and right. The sensor accommodating section 14 provides a space partitioned by the upper inclined plate 16, the rear plate 17, the lower inclined plate 18, and the side plates 19 as a sensor accommodating space 21 in which the moisture sensor 15 is accommodated.

[0038] As shown in FIG. 3, a cover 22 is attached to the front of the front wall 13 of the grain tank 6 so as to close the sensor accommodating space 21. In FIG. 4, the cover 22 is removed from the front wall 13. The vertical dimension of the cover 22 is shorter than the vertical distance between the front edge of the upper inclined plate 16 and the front edge of the lower inclined plate 18, and gaps 23 and 24 are formed between the front edge of the upper inclined plate 16 and the upper edge of the cover 22 and between the front edge of the lower inclined plate 18 and the lower edge of the cover 22 when the cover 22 is attached to the front of the front wall 13. This allows heat to escape from the sensor accommodating space 21 through the gaps 23 and 24, and even if water enters the sensor accommodating space 21 from the outside, the water can be drained from the sensor accommodating space 21 through the gap 24. In addition, since the lower inclined plate 18 is inclined downward toward the front, water can be prevented from accumulating on the lower inclined plate 18.

[0039] However, if a gap 23 is formed between the front edge of the upper inclined plate 16 and the upper edge of the cover 22, when high-pressure water is sprayed toward the gap 23, the water may enter the sensor accommodating space 21 through the gap 23. To prevent the water that has entered the sensor accommodating space 21 from the gap 23 from splashing on the moisture sensor 15, a shield 25 is attached to the upper inclined plate 16 as shown in Fig. 4. The shield 25 integrally includes a rectangular plate-shaped contact portion 26 that contacts the upper inclined plate 16 and a rectangular plate-shaped water blocking portion 27 that extends downward from the contact portion 26. The contact portion 26 is fixed to the upper inclined plate 16 by welding.

[0040] FIG. 5 is a rear view of the moisture sensor 15.

[0041] The moisture sensor 15 includes a box-shaped sensor case 31. A receiving opening 32 for receiving grains into the sensor case 31 is formed on the rear surface of the sensor case 31. The receiving opening 32 has a symmetrical shape, and includes a V-shaped lower side 33 that opens upward, a first left side 34 that extends upward from the upper left end of the lower side 33 and inclines at a relatively small angle to the left in the up-down direction (vertical direction), a second left side 35 that extends upward from the upper end of the first left side 34 and inclines at a relatively large angle to the left in the up-down direction, a first right side 36 that extends upward from the upper right end of the lower side 33 and inclines at a relatively small angle to the right in the up-down direction, and a second right side 37 that extends upward from the upper end of the first right side 36 and inclines at a relatively large angle to the right in the up-down direction. A flat surface extends forward from each of the first left side 34, the second left side 35, the first right side 36 and the second right side 37, and these flat surfaces function as guide surfaces that guide the kernels into the sensor case 31.

[0042] A pair of electrode rollers 41, 42 are provided in the roller accommodating space behind the receiving port 32 within the sensor case 31. The electrode rollers 41, 42 are integral with roller shafts 43, 44 that extend in the front-rear direction parallel to each other. The peripheral surfaces of the electrode rollers 41, 42 are arranged close to each other in the left-right direction. Between the peripheral surfaces of the electrode rollers 41 and 42, for example, there is a gap according to the size of rice (hulled rice), a gap slightly smaller than the width of rice (length in the direction perpendicular to the longitudinal direction). A large number of minute projections and recesses are formed on the peripheral surfaces of the electrode rollers 41, 42.

[0043] A motor 45 (see FIG. 6) is provided inside the sensor case 31, and the pair of electrode rollers 41, 42 rotate forward and backward by the power of the motor 45. When the electrode rollers 41, 42 rotate forward, the left electrode roller 41 rotates clockwise, and the right electrode roller 42 rotates counterclockwise, as viewed from inside the grain tank 6. When the electrode rollers 41, 42 rotate reversely, the left electrode roller 41 rotates counterclockwise, and the right electrode roller 42 rotates clockwise, as viewed from inside the grain tank 6.

[0044] In addition, a guide member 46 is attached to the inner surface of the front wall 13. The guide member 46 has a shape obtained by bending a flat plate into a V-shape, with the bending line positioned lower toward the front and the front end (lower end) positioned on a plane extending forward from the lower side 33 of the receiving opening 32 of the sensor case 31.

[0045] Some of the grains scattered from the discharge section 12 in the grain tank 6 reach the position of the sensor case 31 and are directly received into the sensor case 31 through the receiving port 32 of the sensor case 31. In addition, the grains that reach the guide member 46 flow on the guide member 46 towards the sensor case 31, drop from the guide member 46, and are received into the sensor case 31 through the receiving port 32. The grains received into the sensor case 31 through the receiving port 32 are accumulated on the electrode rollers 41, 42. Then, when the electrode rollers 41, 42 rotate forward, the grains are sandwiched between the electrode rollers 41, 42 and crushed.

[0046] Furthermore, when the electrode rollers 41, 42 rotate in the reverse direction, brushes (not shown) come into contact with the circumferential surfaces of the electrode rollers 41, 42, and the circumferential surfaces (surfaces) of the electrode rollers 41, 42 are cleaned.

[0047] The bottom of the roller accommodating space in which the electrode rollers 41, 42 are accommodated is open. Therefore, the grains received into the sensor case 31 from the receiving opening 32 and the crushed grains scraped off from the peripheral surfaces of the electrode rollers 41, 42 do not accumulate in the roller accommodating space except on the electrode rollers 41, 42, but are discharged from the roller accommodating space into the grain tank 6 through a return passage 47 provided below the moisture sensor 15.

[0048] <Electrical configuration of combine> FIG. 6 is a block diagram showing a main part of the electrical configuration of the combine harvester 1. As shown in FIG.

[0049] The combine harvester 1 is equipped with an ECU (Electronic Control Unit) 51. The ECU 51 includes a microcomputer (microcontroller), and the microcomputer includes, for example, a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory).

[0050] The ECU 51 has a measurement method switching unit 52, a measurement processing unit 53, a sensor output value acquisition unit 54, and a sensor output value correction unit 55 as functional processing units for measuring the moisture content of the grains stored in the grain tank 6. These functional processing units are realized in software by program processing, or by hardware such as a logic circuit, or by a combination of these.

[0051] The measurement method switching unit 52 switches and sets the measurement method for measuring the moisture content of the grain, in other words, the method for controlling the operation of the moisture sensor 15 to measure the moisture content of the grain. Specifically, two measurement methods, a first measurement method and a second measurement method, are prepared as the measurement method for measuring the moisture content of the grain. Depending on the crop (type of grain) set as the target for moisture content measurement, the measurement method switching unit 52 switches and sets the measurement method for measuring the moisture content of the crop between the first measurement method and the second measurement method.

[0052] The measurement processing unit 53 controls the motor 45 of the moisture sensor 15 in accordance with the first measurement method or the second measurement method set by the measurement method switching unit 52, switches between forward rotation, reverse rotation and stoppage of the electrode rollers 41, 42, and switches between supplying and stopping a constant voltage between the electrode rollers 41, 42.

[0053] An output signal from a signal output circuit 56 provided in the moisture sensor 15 is input to the sensor output value acquisition unit 54. When grains are crushed between the electrode rollers 41, 42 due to the forward rotation of the electrode rollers 41, 42, a constant voltage is supplied between the electrode rollers 41, 42, and the signal output circuit 56 outputs a signal having a voltage value corresponding to the electrical resistance value between the electrode rollers 41, 42. The smaller the electrical resistance value between the electrode rollers 41, 42, the larger the value of the signal output from the signal output circuit 56. The sensor output value acquisition unit 54 performs an averaging process that averages the values ​​of the signals input from the signal output circuit 56 to obtain a sensor output value. The averaging process is performed according to the content of the crop set as the target for moisture measurement.

[0054] The sensor output value correction unit 55 corrects the sensor output value acquired by the sensor output value acquisition unit 54 .

[0055] A calibration curve 57 showing the relationship between the sensor output value and the moisture content is stored in the non-volatile memory of the ECU 51. In the ECU 51, the moisture content corresponding to the sensor output value corrected by the sensor output value correcting unit 55 is obtained from the calibration curve 57, and the obtained moisture content is regarded as the moisture content of the grains stored in the grain tank 6.

[0056] Also, in the cabin 4, a meter panel 58 is arranged at a position where a user seated in the driver's seat can see and operate it. The meter panel 58 is made of a touch panel configured by overlapping a pressure-sensitive or capacitance-type transparent film switch on a display such as a liquid crystal display. Various information, images of operation buttons, and the like are displayed on the meter panel 58. When the user touches an operation button, an instruction corresponding to the type of the operation button that was touched is received by the meter panel 58. When the instruction is received by the meter panel 58, a signal corresponding to the content of the instruction is input from the meter panel 58 to the ECU 51. Also, the user can input a numerical value by touching the meter panel 58. When a numerical value is input, a signal corresponding to the input numerical value is input from the meter panel 58 to the ECU 51.

[0057] Settings required for processing by the measurement method switching unit 52 and the sensor output value acquiring unit 54, i.e., settings of the crops to be measured for moisture content, can be made by touching the meter panel 58. Also, on the meter panel 58, settings of the crops to be worked on by the working devices mounted on the combine harvester 1, i.e., the thresher 5 and the reaper 7, can be made. The crops to be worked on by the thresher 5 and the reaper 7 and the crops to be measured for moisture content are the same, so when any of them is set, the settings are reflected in the other settings. For example, when a crop to be worked on by the thresher 5 is set, the crop to be worked on by the reaper 7 is set to the same crop, and the crop to be measured for moisture content is also set to the same crop.

[0058] Furthermore, by touching the meter panel 58, the reference moisture content required for the sensor output value correction unit 55 to correct the sensor output value can be input.

[0059] <Measurement method selection process> FIG. 7 is a flowchart showing the flow of the measurement method selection process.

[0060] For example, when the combine harvester 1 starts harvesting a crop, the measurement method switching unit 52 of the ECU 51 executes a measurement method selection process to switch the measurement method for measuring the moisture content of grains depending on the crop.

[0061] In the measurement method selection process, it is determined whether or not a target crop for the work implements (thresher 5, harvester 7) mounted on the combine 1 has been set (step S1).

[0062] If a crop has already been set for the working implement (YES in step S1), that setting is also reflected in the setting of the crop to be measured for moisture content, so that a measurement method corresponding to the set crop is selected from the first measurement method and the second measurement method (step S2), and the measurement method selection process is terminated.

[0063] When the crop to be measured for moisture content is set to rice or wheat, the first measurement method is selected as the measurement method for measuring the moisture content of the grain. On the other hand, when the crop to be measured for moisture content is set to barley, the second measurement method is selected as the measurement method for measuring the moisture content of the grain. The details of the first measurement method and the second measurement method will be described later.

[0064] If a crop has not been set for the working implement (NO in step S1), it is determined whether a crop for which moisture content is to be measured has been set (step S3).

[0065] When the crop to be measured for moisture content is set (step S3), a measurement method corresponding to the set crop is selected from two methods, the first measurement method and the second measurement method (step S2), and the measurement method selection process is terminated.

[0066] If a predetermined time has elapsed since the start of the measurement method selection process, but the crop to be measured for moisture content has not been set (NO in step S3), a default measurement method, for example, the first measurement method, is selected (step S4), and the measurement method selection process is terminated.

[0067] FIG. 8 is a diagram showing the content of the first measurement method.

[0068] As described above, when the crop to be measured for moisture content is set to rice or wheat, the first measurement method is selected as the measurement method for measuring the moisture content of the grain. In measuring the moisture content by the first measurement method, the measurement processing unit 53 controls the operation of the moisture sensor 15 according to the first measurement method.

[0069] In this control, the electrode rollers 41, 42 are kept stopped and wait for a first period of time (e.g., 90 seconds) from when the discharge of grains from the discharge section 12 into the grain tank 6 begins until grains are stored in the sensor case 31 of the moisture sensor 15.

[0070] After the first time period has elapsed, the motor 45 is driven in the forward direction to rotate the electrode rollers 41, 42 in the forward direction. When the electrode rollers 41, 42 rotate in the forward direction, grains are sandwiched between the electrode rollers 41, 42 and crushed. While the electrode rollers 41, 42 are rotating in the forward direction, a constant voltage is applied between the electrode rollers 41, 42, and a signal having a voltage value corresponding to the electrical resistance value between the electrode rollers 41, 42 is output from the signal output circuit 56. The forward rotation of the electrode rollers 41, 42 and the application of the constant voltage between the electrode rollers 41, 42 continue for a second time period (e.g., 10 seconds).

[0071] When a second time has elapsed since the electrode rollers 41, 42 started to rotate in the forward direction and a voltage was applied between the electrode rollers 41, 42, the motor 45 is stopped once and then driven in the reverse direction. The reverse driving of the motor 45 rotates the electrode rollers 41, 42 in the reverse direction, cleaning the peripheral surfaces of the electrode rollers 41, 42. When the reverse driving of the motor 45 continues for a third time, the motor 45 is stopped and control of the operation of the moisture sensor 15 according to the first measurement method for measuring the moisture content of grain is terminated.

[0072] Since a gap is provided between the peripheral surfaces of the electrode rollers 41 and 42 according to the size of the rice, small grains such as rice or wheat can easily get between the electrode rollers 41 and 42. Therefore, when the electrode rollers 41 and 42 rotate in the forward direction, the grains on the electrode rollers 41 and 42 are continuously caught between the electrode rollers 41 and 42 and crushed. Therefore, there is little fluctuation in the value of the signal output from the signal output circuit 56 of the moisture sensor 15 from when the value rises until the grains disappear from the electrode rollers 41 and 42.

[0073] Taking these characteristics into consideration, in the averaging process when the crop set as the target for moisture content measurement is rice or wheat and the operation of the moisture sensor 15 is controlled according to the first measurement method, the sensor output value acquisition unit 54 samples the signal values ​​input from the signal output circuit 56 to the sensor output value acquisition unit 54 at a predetermined sampling period during a predetermined period during the forward rotation of the electrode rollers 41, 42. Then, an average value and standard deviation are calculated from the sampled values, and the standard deviation is multiplied by a constant and the value is added to the average value to calculate an average value of the signal values ​​output from the signal output circuit 56, and this value is used as the sensor output value.

[0074] FIG. 9 is a diagram showing the content of the second measurement method.

[0075] When the crop to be measured for moisture content is set to barley, the second measurement method is selected as the method for measuring the moisture content of the grain. In measuring the moisture content by the second measurement method, the measurement processing unit 53 controls the operation of the moisture sensor 15 in accordance with the second measurement method.

[0076] In this control, the electrode rollers 41, 42 are kept stopped and wait for a fourth hour (for example, 40 to 50 seconds) from when the discharge of grains from the discharge section 12 into the grain tank 6 begins until grains are stored in the sensor case 31 of the moisture sensor 15.

[0077] When the fourth time has elapsed, the motor 45 is driven in the forward direction to rotate the electrode rollers 41, 42 in the forward direction. When the electrode rollers 41, 42 rotate in the forward direction, grains are sandwiched between the electrode rollers 41, 42 and crushed. While the electrode rollers 41, 42 are rotating in the forward direction, a constant voltage is applied between the electrode rollers 41, 42, and a signal having a voltage value corresponding to the electrical resistance value between the electrode rollers 41, 42 is output from the signal output circuit 56. The forward rotation of the electrode rollers 41, 42 and the application of the constant voltage between the electrode rollers 41, 42 continue for a fifth time (e.g., 3 seconds) that is shorter than the second time.

[0078] When a fifth time has elapsed since the electrode rollers 41, 42 started to rotate forward and a voltage was applied between the electrode rollers 41, 42, the motor 45 is stopped once and then driven in the reverse direction. The reverse driving of the motor 45 rotates the electrode rollers 41, 42 in the reverse direction, and the peripheral surfaces of the electrode rollers 41, 42 are cleaned. When the reverse driving of the motor 45 continues for a sixth time (e.g., 3 seconds), the motor 45 is stopped once and then driven in the forward direction. The forward driving of the motor 45 rotates the electrode rollers 41, 42 forward. At this time, no voltage is applied between the electrode rollers 41, 42. When the forward driving of the motor 45 continues for a seventh time (e.g., 2 seconds), the motor 45 is stopped.

[0079] When the motor 45 stops, the electrode rollers 41, 42 stop, and the grains are stored in the sensor case 31. When an eighth time (for example, seven seconds) has elapsed since the motor 45 stopped, the following cycle is repeated eight times (looped): forward driving of the motor 45 (forward rotation of the electrode rollers 41, 42) and application of a voltage between the electrode rollers 41, 42 for a fifth time, reverse driving of the motor 45 for a sixth time, forward driving of the motor 45 for a seventh time, and stopping of the motor 45 for an eighth time.

[0080] Then, when the motor 45 is stopped for the ninth time for eight hours, the motor 45 is driven in the forward direction to rotate the electrode rollers 41, 42 in the forward direction and to apply a voltage between the electrode rollers 41, 42 for the fifth hour. After that, when the motor 45 is driven in the reverse direction for a sixth hour, the motor 45 is stopped once and then driven in the forward direction. At this time, no voltage is applied between the electrode rollers 41, 42. When the motor 45 is driven in the forward direction for a seventh hour, the motor 45 is stopped and the control of the operation of the moisture sensor 15 by the second measurement method for measuring the moisture content of grain is terminated.

[0081] Compared to rice, wheat, etc., barley is less likely to enter between the electrode rollers 41, 42. When a grain that is less likely to enter between the electrode rollers 41, 42 is set as the target for moisture content measurement, there is a risk that a period in which the value of the signal output from the moisture sensor is extremely small will occur and that this period will continue for a long time because the grain does not enter between the electrode rollers 41, 42 while the electrode rollers 41, 42 are rotating in the forward direction.

[0082] Therefore, when the crop set as the subject for moisture content measurement is barley, a measurement period (fifth time) is set that is shorter than the measurement period (second time) during which the electrode rollers 41, 42 are rotated in the forward direction and a constant voltage is applied between the electrode rollers 41, 42 by the first measurement method, and the sensor output value is determined from the value of the signal input from the signal output circuit 56 to the sensor output value acquisition unit 54 during that measurement period.

[0083] That is, in the averaging process when the operation of the moisture sensor 15 is controlled according to the second measurement method, the peak values ​​of the signal input from the signal output circuit 56 to the sensor output value acquisition unit 54 during a total of 10 measurement periods are acquired by the sensor output value acquisition unit 54. Then, the average value of the acquired 10 peak values ​​is calculated, and this average value is used as the sensor output value.

[0084] <Sensor output correction> In order for the sensor output value correcting unit 55 to correct the sensor output value acquired by the sensor output value acquiring unit 54, it is necessary to input the reference moisture content. The reference moisture content is a value measured by an apparatus other than the combine harvester 1 of the moisture content of grains that are estimated to contain the same moisture content as the grains crushed by the moisture sensor 15 when the sensor output value is acquired. For example, grains harvested from a field in the same section as the grains crushed by the moisture sensor 15 can be cited as an example of grains that are estimated to contain the same moisture content as the grains crushed by the moisture sensor 15. The moisture content of grains harvested from a field in the same section as the grains crushed by the moisture sensor 15 can be measured by a moisture meter or a dryer for drying grains owned by the user, and the measured moisture content can be used as the reference moisture content. In this embodiment, the reference moisture content can be input by touching the meter panel 58.

[0085] FIG. 10 is a diagram for explaining a method for correcting the sensor output value.

[0086] When a reference moisture content for the sensor output value (combine measurement value) acquired by the sensor output value acquisition unit 54 is input, the sensor output value correction unit 55 determines a sensor output value corresponding to the reference moisture content using a calibration curve 57 stored in the non-volatile memory of the ECU 51. Then, the deviation between the sensor output value corresponding to the reference moisture content and the sensor output value acquired by the sensor output value acquisition unit 54 is determined as a correction value, and the correction value is held in the volatile memory of the ECU 51.

[0087] Thereafter, when a sensor output value is acquired by the sensor output value acquisition unit 54, the sensor output value is corrected using the correction value, and the moisture content corresponding to the corrected sensor output value is found from the calibration curve 57.

[0088] The sensor output values ​​may be corrected each time the sensor output values ​​are acquired, or the sensor output values ​​may be temporarily stored in a non-volatile memory and then corrected all at once later.

[0089] <Action and effect> As described above, when the crop to be measured for moisture content is set to rice or wheat, the first measurement method is selected as the measurement method for measuring the moisture content of the grain, and the operation of the moisture sensor 15 is controlled according to the second measurement method. On the other hand, when the crop to be measured for moisture content is set to barley, the second measurement method is selected as the measurement method for measuring the moisture content of the grain, and the operation of the moisture sensor 15 is controlled according to the second measurement method. This makes it possible to determine a sensor output value according to the size of the grain from the output signal of the moisture sensor 15, and to determine the moisture content corresponding to the sensor output. Therefore, the moisture content in the grain can be measured with high accuracy.

[0090] Further, a sensor output value corresponding to a reference moisture content input by touching meter panel 58 is obtained using calibration curve 57 stored in non-volatile memory of ECU 51. Then, the deviation between the sensor output value corresponding to the reference moisture content and the sensor output value acquired by sensor output value acquisition unit 54 is obtained as a correction value. The deviation between the sensor output value corresponding to the reference moisture content obtained from calibration curve 57 and the sensor output value acquired by sensor output value acquisition unit 54 is an error caused by the characteristics of moisture sensor 15, and the sensor output value is corrected using the deviation as a correction value, thereby eliminating the error from the sensor output value. As a result, the moisture content corresponding to the corrected sensor output value can be obtained from calibration curve 57, thereby making it possible to measure the moisture content in the grain with higher accuracy.

[0091] <Modification> Although one embodiment of the present invention has been described above, the present invention can be embodied in other forms.

[0092] 11, a communication unit 61 is provided that communicatively connects the ECU 51 and an external device, and the settings of the crops to be subjected to moisture content measurement may be transmitted to the ECU 51 from an external device, such as a server 62 or a terminal 63. Also, a reference moisture content may be transmitted from the server 62 or the terminal 63 to the ECU 51. When the operation of a dryer 64 that dries grains is managed by the server 62, the moisture content of the grains measured by the dryer 64 is transmitted from the dryer 64 to the server 62, and therefore the moisture content of the grains measured by the dryer 64 may be transmitted from the server 62 to the ECU 51 as the reference moisture content.

[0093] In the above embodiment, when the crop to be measured for moisture content is set to rice or wheat, the first measurement method is selected as the measurement method for measuring the moisture content of the grain, and when the crop to be measured for moisture content is set to barley, the second measurement method is selected as the measurement method for measuring the moisture content of the grain. However, without being limited to this, when the crop to be measured for moisture content is set to small grains such as rice or wheat, the first measurement method may be selected as the measurement method for measuring the moisture content of the grain, and when the crop to be measured for moisture content is set to large grains such as barley, the second measurement method may be selected as the measurement method for measuring the moisture content of the grain.

[0094] In addition, various design modifications can be made to the above-described configuration within the scope of the claims. [Explanation of symbols]

[0095] 5: Threshing equipment (work equipment) 7: Reaping device (work device) 15: Moisture sensor 41: Electrode roller 42: Electrode roller 51: ECU (control unit) 57: Calibration curve 58: Meter panel (operating device, input device) 62: Server (input device) 63: Terminal (input device)

Claims

1. a moisture sensor that crushes grains between a pair of electrode rollers by rotation of the electrode rollers and outputs a signal corresponding to an electrical resistance value between the electrode rollers when the grains are being crushed; a control device that controls the operation of the moisture sensor, receives a signal output from the moisture sensor, calculates a sensor output value from the received signal, and calculates the moisture content corresponding to the sensor output value from a calibration curve; The control device switches a method for controlling the operation of the moisture sensor among a plurality of control methods depending on the type of grain set as a target for moisture content measurement, The plurality of control methods include: a first control method for setting a relatively long period of time and controlling an operation of the moisture sensor so that a signal is output from the moisture sensor during the relatively long period of time; and a second control method for repeatedly setting relatively short periods of time at time intervals and controlling the operation of the moisture sensor so that a signal is output from the moisture sensor during each of the short periods.

2. An operating device that is operated to set the information, The moisture content measuring system according to claim 1 , wherein the type of grain is set by operating the operating device.

3. a working device for performing work for harvesting grains; The type of grain to be subjected to the work by the working device is set by operating the operating device, The moisture amount measuring system according to claim 2 , wherein the control device switches between a method of controlling the operation of the moisture sensor among a plurality of control methods depending on a type of grain set as a target of the work performed by the work device.

4. The moisture amount measuring system according to claim 3 , wherein the operating device is a threshing device that sorts and collects sorting objects obtained by threshing a crop.

5. a moisture sensor that crushes grains between a pair of electrode rollers by rotating the electrode rollers and outputs a signal corresponding to an electrical resistance value between the electrode rollers when the grains are being crushed; a control device that controls the operation of the moisture sensor, receives a signal output from the moisture sensor, calculates a sensor output value from the received signal, and calculates the moisture content corresponding to the sensor output value from a calibration curve; The control device switches a method for controlling the operation of the moisture sensor among a plurality of control methods depending on the size of the grain set as the target for moisture content measurement; The plurality of control methods include: a first control method for setting a relatively long period of time and controlling an operation of the moisture sensor so that a signal is output from the moisture sensor during the relatively long period of time; and a second control method for repeatedly setting relatively short periods of time at time intervals and controlling the operation of the moisture sensor so that a signal is output from the moisture sensor during each of the short periods.

6. An input device for inputting a reference moisture content of grain to the control device, The reference moisture content is a measured value of the moisture content of grains estimated to contain the same moisture content as the grains crushed by the moisture sensor, measured by an instrument other than the control device; The moisture content measurement system according to claim 1 or 5, wherein the control device determines a value corresponding to the reference moisture content from the calibration curve, and corrects the sensor output value using a deviation between the determined value and the sensor output value as a correction value.

Images