A device and method for detecting moisture content in wood

Abstract

The application discloses a kind of detection device and method of wood moisture content, including two-channel microwave source, transmitting antenna, receiving antenna and signal processing module;Two-channel microwave source includes first signal transmitting end and second signal transmitting end, first signal transmitting end is connected with the first receiving end of signal processing module, and second signal transmitting end is connected with transmitting antenna;First signal transmitting end transmits reference signal to the first receiving end of signal processing module, and second signal transmitting end transmits test signal to transmitting antenna;Detected wood is placed between transmitting antenna and receiving antenna, and receiving antenna is connected with the second receiving end of signal processing module;Receiving antenna is used to receive the test signal that transmitting antenna transmits;And test signal is sent to the second receiving end of signal processing module;Signal processing module determines the moisture content of detected wood according to reference signal and test signal, can remove the error caused by the fluctuation of signal source, improve the accuracy of wood moisture content detection.

Description

Technical Field

[0001] This invention relates to the field of material property measurement, and more particularly to a device and method for detecting the moisture content of wood. Background Technology

[0002] Wood is one of the most important raw materials in modern industry. Due to its lightweight, ease of shaping, and impact resistance, it is widely used in production and daily life. Wood moisture content is a crucial indicator affecting wood properties. High moisture content makes wood prone to corrosion, while excessively low moisture content can lead to cracking and compromise its physical properties. Therefore, accurately measuring wood moisture content is of paramount practical value.

[0003] Current methods for detecting wood moisture content suffer from drawbacks such as long processing time, high cost, and low accuracy. In applications utilizing microwave transmission characteristics for moisture content detection, fluctuations in the microwave source can introduce errors in the detection of wood moisture content, and these errors are difficult to eliminate, resulting in low accuracy in the detection of wood moisture content. Summary of the Invention

[0004] This invention provides a device and method for detecting the moisture content of wood, so as to improve the accuracy of wood moisture content detection.

[0005] According to one aspect of the present invention, a device for detecting the moisture content of wood is provided, characterized in that it comprises: a dual-channel microwave source, a transmitting antenna, a receiving antenna, and a signal processing module;

[0006] The dual-channel microwave source includes a first signal transmitting end and a second signal transmitting end. The first signal transmitting end is communicatively connected to the first receiving end of the signal processing module, and the second signal transmitting end is communicatively connected to the transmitting antenna. The first signal transmitting end transmits a reference signal to the first receiving end of the signal processing module, and the second signal transmitting end transmits a test signal to the transmitting antenna.

[0007] The wood to be tested is placed between the transmitting antenna and the receiving antenna, and the receiving antenna is communicatively connected to the second receiving end of the signal processing module.

[0008] The receiving antenna is used to receive the test signal transmitted by the transmitting antenna; and to send the test signal to the second receiving end of the signal processing module;

[0009] The signal processing module is used to determine the moisture content of the wood being tested based on the reference signal and the test signal.

[0010] Optionally, the signal processing module includes: a first signal processing module, a second signal processing module, and a processor;

[0011] The receiving end of the first signal processing module is communicatively connected to the first signal transmitting end of the dual-channel microwave source, and the output end of the first signal processing module is electrically connected to the first input end of the processor; the first signal processing module is used to output a first processed signal to the processor according to the reference signal;

[0012] The receiving end of the second signal processing module is communicatively connected to the receiving antenna, and the output end of the second signal processing module is electrically connected to the second input end of the processor; the second signal processing module is used to output a second processed signal to the processor according to the test signal;

[0013] The processor is used to determine the moisture content of the wood being tested based on the first processing signal and the second processing signal.

[0014] Optionally, the dual-channel microwave source further includes a modulation signal receiver;

[0015] The processor's modulation signal output terminal is communicatively connected to the modulation signal receiving terminal of the dual-channel microwave source.

[0016] The processor is also configured to provide a modulation signal of a preset frequency to the dual-channel microwave source, wherein the dual-channel microwave source generates a modulation reference signal based on the reference signal and the modulation signal, and transmits the modulation reference signal to the first signal processing module through the first signal transmitting end, and generates a modulation test signal based on the test signal and the modulation signal, and transmits the modulation test signal to the transmitting antenna through the second signal transmitting end.

[0017] Optionally, the first signal processing module includes: a first signal acquisition unit, a first signal amplification unit, and a first filtering unit;

[0018] The receiving end of the first signal acquisition unit is communicatively connected to the first signal transmitting end of the dual-channel microwave source; the input end of the first signal amplification unit is electrically connected to the output end of the first signal acquisition unit, the output end of the first signal amplification unit is electrically connected to the input end of the first filtering unit, and the output end of the first filtering unit is electrically connected to the first receiving end of the processor.

[0019] The second signal processing module includes: a second signal acquisition unit, a second signal amplification unit, and a second filtering unit;

[0020] The receiving end of the second signal acquisition unit is communicatively connected to the receiving antenna; the input end of the second signal amplification unit is electrically connected to the output end of the second signal acquisition unit; the output end of the second signal amplification unit is electrically connected to the input end of the second filtering unit; and the output end of the second filtering unit is electrically connected to the second receiving end of the processor.

[0021] Optionally, the wood moisture content detection device further includes: a host computer;

[0022] The host computer is communicatively connected to the dual-channel microwave source.

[0023] The host computer is used to send microwave parameters to the dual-channel microwave source; the dual-channel microwave source adjusts the frequencies of the reference signal and the test signal according to the microwave parameters.

[0024] Optionally, the host computer is also communicatively connected to the signal processing module;

[0025] The signal processing module is also used to send the moisture content of the wood to the host computer after determining the moisture content of the wood being tested.

[0026] The host computer is also used to save the moisture content and display the moisture content.

[0027] According to another aspect of the present invention, a method for detecting the moisture content of wood is provided, which is performed using the aforementioned wood moisture content detection device, comprising:

[0028] The signal processing module acquires the reference signal through the first receiving end;

[0029] The signal processing module acquires the test signal through the second receiving end;

[0030] The moisture content of the wood being tested is determined based on the reference signal and the test signal.

[0031] Optionally, the signal processing module acquires a reference signal through a first receiving end, including:

[0032] The signal processing module acquires a first reference signal emitted by the dual-channel microwave source when no wood under test is placed between the transmitting antenna and the receiving antenna through the first receiving end; and acquires a second reference signal emitted by the dual-channel microwave source when the wood under test is placed between the transmitting antenna and the receiving antenna.

[0033] The signal processing module acquires the test signal through the second receiver, including:

[0034] The signal processing module acquires the first test signal emitted by the dual-channel microwave source when no wood under test is placed between the transmitting antenna and the receiving antenna through the second receiving end; and acquires the second test signal emitted by the dual-channel microwave source when the wood under test is placed between the transmitting antenna and the receiving antenna.

[0035] Optionally, determining the moisture content of the wood being tested based on the reference signal and the test signal includes:

[0036] The signal source error is determined based on the first reference signal and the second reference signal;

[0037] A first attenuation value is determined based on the first test signal and the second test signal;

[0038] Based on a preset formula, the moisture content of the wood being tested is determined according to the signal source error and the first attenuation value.

[0039] Optionally, the preset formula is:

[0040] W = 20 * k * log 10 [(VQ) / N0]+b

[0041] Wherein, W is the actual moisture content of the wood being tested, V is the first attenuation value, Q is the signal source error, and k and b are constants.

[0042] The wood moisture content detection device provided in this invention uses a dual-channel microwave source, capable of transmitting two identical microwave signals through a first signal transmitter and a second signal transmitter. The first signal transmitter is directly connected to a signal processing module, allowing a reference signal to be directly transmitted from the first signal transmitter to the first receiver of the signal processing module. A transmitting antenna and a receiving antenna are positioned between the second signal transmitter and the second receiver of the signal processing module, allowing the test signal to be transmitted to the second receiver of the signal processing module. When the moisture content of the wood to be tested needs to be detected, the wood can be placed between the transmitting and receiving antennas to obtain the reference and test signals at this time. By combining the reference and test signals when no wood is placed between the transmitting and receiving antennas, signal source errors caused by signal source fluctuations can be eliminated, effectively improving the accuracy of wood moisture content detection.

[0043] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of a wood moisture content detection device provided in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of another wood moisture content detection device provided in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the structure of another wood moisture content detection device provided in an embodiment of the present invention;

[0048] Figure 4 This is a flowchart of a method for detecting the moisture content of wood provided in an embodiment of the present invention;

[0049] Figure 5 This is a flowchart of another method for detecting the moisture content of wood provided in an embodiment of the present invention. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a series of steps or units, not necessarily limited to those explicitly listed, and may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0052] Figure 1 This is a schematic diagram of a wood moisture content detection device provided in an embodiment of the present invention, as shown below. Figure 1As shown, the wood moisture content detection device includes: a dual-channel microwave source 10, a transmitting antenna 20, a receiving antenna 30, and a signal processing module 40; the dual-channel microwave source 10 includes a first signal transmitting end SO1 and a second signal transmitting end SO2. The first signal transmitting end SO1 is communicatively connected to the first receiving end IN1 of the signal processing module 40, and the second signal transmitting end SO2 is communicatively connected to the transmitting antenna 20; the first signal transmitting end SO1 transmits a reference signal to the first receiving end IN1 of the signal processing module 40, and the second signal transmitting end SO2 transmits a test signal to the transmitting antenna 20; the wood to be tested 00 is placed between the transmitting antenna 20 and the receiving antenna 30, and the receiving antenna 30 is communicatively connected to the second receiving end IN2 of the signal processing module 40; the receiving antenna 30 is used to receive the test signal transmitted by the transmitting antenna 20 and send the test signal to the second receiving end IN2 of the signal processing module 40; the signal processing module 40 is used to determine the moisture content of the wood to be tested 00 based on the reference signal and the test signal.

[0053] Specifically, the dual-channel microwave source 10 can emit two identical microwave signals, namely, the reference signal emitted by its first signal transmitter SO1 and the test signal emitted by its second signal transmitter SO2 are the same. No detection device or object is placed between the first signal transmitter SO1 and the first receiver IN1 of the signal processing module 40; that is, the dual-channel microwave source 10 directly transmits the reference signal to the first receiver IN1 of the signal processing module 40 through the first signal transmitter SO1. Furthermore, an antenna module, namely a transmitting antenna 20 and a receiving antenna 30, is placed between the second signal transmitter SO2 and the second receiver IN2 of the signal processing module 40. The transmitting antenna 20 can receive the test signal emitted by the second signal transmitter SO2, and the transmitting antenna 20 can radiate the test signal to the receiving antenna 30, which then transmits it to the second receiver IN2 of the signal processing module 40. This allows the signal processing module 40 to determine the moisture content of the wood being tested based on the attenuation difference between the received reference signal and the test signal. The transmitting antenna 20 and the receiving antenna 30 are arranged with their horn openings facing each other, and the transmitting antenna 20 and the receiving antenna 30 can be placed on a base (not shown in the figure). The base has a scale that can adjust the distance between the transmitting antenna 20 and the receiving antenna 30, and make the centers of the transmitting antenna 20 and the receiving antenna 30 lie on a horizontal line.

[0054] For example, when detecting the moisture content of the wood 00 being tested, the first reference signal M0 and the first test signal N0 can be acquired first when the antenna module is unloaded. That is, the reference signal and test signal acquired by the signal processing module 40 when the wood 00 being tested is not placed between the transmitting antenna 20 and the receiving antenna 30. Then, the wood 00 being tested is placed between the transmitting antenna 20 and the receiving antenna 30, and the signal processing module 40 acquires the reference signal and test signal at this time again, that is, the second reference signal M1 and the second test signal N1. Then, the difference Q = M0 - M1 between the first reference signal M0 and the second reference signal M1 is the result of the two tests. The error between the received reference signals, i.e. the signal source error under load and no load, is the difference V = N1 - N0 between the first test signal N0 and the second test signal N1. This difference includes the attenuation caused by the wood being tested 00 itself, the attenuation caused by the moisture content in the wood being tested 00, and the signal source error Q. Therefore, subtracting the signal source error Q (VQ) from the difference V between the first test signal N0 and the second test signal N1 can eliminate the signal source error Q. In this way, the moisture content of the wood being tested 00 can be further determined based on the attenuation value (VQ) after eliminating the signal source error Q, which effectively improves the accuracy of detecting the moisture content of the wood being tested 00.

[0055] The wood moisture content detection device provided in this invention uses a dual-channel microwave source, capable of transmitting two identical microwave signals through a first signal transmitter and a second signal transmitter. The first signal transmitter is directly connected to the first receiver of the signal processing module, allowing a reference signal to be directly transmitted from the first signal transmitter to the first receiver. A transmitting antenna and a receiving antenna are positioned between the second signal transmitter and the second receiver of the signal processing module, allowing the test signal to be transmitted to the second receiver. When the moisture content of the wood to be tested needs to be detected, the wood can be placed between the transmitting and receiving antennas to obtain the reference and test signals. By combining the reference and test signals obtained without placing the wood between the transmitting and receiving antennas, signal source errors caused by signal source fluctuations can be eliminated, effectively improving the accuracy of wood moisture content detection.

[0056] Optional, Figure 2 This is a schematic diagram of another wood moisture content detection device provided in an embodiment of the present invention, as shown below. Figure 2As shown, the signal processing module 40 includes: a first signal processing module 41, a second signal processing module 42, and a processor 43; the receiving end of the first signal processing module 41 is communicatively connected to the first signal transmitting end SO1 of the dual-channel microwave source 10, and the output end of the first signal processing module 41 is electrically connected to the first input end IN3 of the processor 43; the first signal processing module 41 is used to output a first processed signal to the processor 43 according to a reference signal; the receiving end of the second signal processing module 42 is communicatively connected to the receiving antenna 30, and the output end of the second signal processing module 42 is electrically connected to the second input end IN4 of the processor 43; the second signal processing module 42 is used to output a second processed signal to the processor 43 according to a test signal; the processor 43 is used to determine the moisture content of the tested wood 00 according to the first processed signal and the second processed signal.

[0057] Specifically, corresponding signal processing modules can be set up for the reference signal and the test signal respectively. That is, a first signal processing module 41 is set up for the reference signal and a second signal processing module 42 is set up for the test signal. The first signal processing module 41 can be connected to the first signal transmitting end SO1 of the dual-channel microwave source 10 via a cable. After receiving the reference signal, it processes the reference signal and generates a first processed signal that can be effectively recognized by the processor 43, and sends it to the processor 43. Similarly, the second signal processing module 42 can be connected to the receiving antenna 30 via a cable. After receiving the test signal, it processes the test signal and generates a second processed signal that can be effectively recognized by the processor 43, and sends the second processed signal to the processor 43. This allows the processor 43 to calculate the moisture content of the wood being tested based on the processed reference signal and the test signal (i.e., the first processed signal and the second processed signal).

[0058] Optional, see reference Figure 2 The dual-channel microwave source 10 also includes a modulation signal receiving terminal SIN; the modulation signal output terminal PO of the processor is communicatively connected to the modulation signal receiving terminal SIN of the dual-channel microwave source; the processor 43 is also used to provide a modulation signal of a preset frequency to the dual-channel microwave source 10. The dual-channel microwave source 10 generates a modulation reference signal based on the reference signal and the modulation signal, and transmits the modulation reference signal to the first signal processing module 41 through the first signal transmitting terminal SO1, and generates a modulation test signal based on the test signal and the modulation signal, and transmits the modulation test signal to the transmitting antenna 20 through the second signal transmitting terminal SO2.

[0059] Specifically, since the microwave signal emitted by the dual-channel microwave source 10 has a high frequency, and such a high frequency microwave signal cannot be transmitted by the antenna module and received by the signal processing module 40, the high-frequency microwave signal can be modulated into a lower-frequency carrier signal. The microwave signal is then transmitted to the signal processing module 40 via the carrier signal. Therefore, the processor 43 can send a modulated signal of a specific frequency to the dual-channel microwave source 10 as a carrier signal. The dual-channel microwave source 10 modulates the microwave signal into the carrier signal, thereby enabling the modulated microwave signal to be effectively transmitted and received. In other words, the reference signal is modulated into the carrier signal to generate a modulated reference signal, which can be transmitted to the first signal processing module 41. Similarly, the test signal is modulated into the carrier signal to generate a modulated test signal, which can be transmitted to the second signal processing module 42.

[0060] Optional, Figure 3 This is a schematic diagram of the structure of another wood moisture content detection device provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the first signal processing module 41 includes: a first signal acquisition unit 411, a first signal amplification unit 412, and a first filtering unit 413; the receiving end of the first signal acquisition unit 411 is communicatively connected to the first signal transmitting end SO1 of the dual-channel microwave source 10; the input end of the first signal amplification unit 412 is electrically connected to the output end of the first signal acquisition unit 411, the output end of the first signal amplification unit 412 is electrically connected to the input end of the first filtering unit 413, and the output end of the first filtering unit 413 is electrically connected to the first receiving end IN3 of the processor 43; the second signal processing module 42 includes: a second signal acquisition unit 421, a second signal amplification unit 422, and a second filtering unit 423; the receiving end of the second signal acquisition unit 421 is communicatively connected to the receiving antenna 30; the input end of the second signal amplification unit 422 is electrically connected to the output end of the second signal acquisition unit 421, the output end of the second signal amplification unit 422 is electrically connected to the input end of the second filtering unit 423, and the output end of the second filtering unit 423 is electrically connected to the second receiving end IN4 of the processor 43.

[0061] Specifically, the receiving end of the first signal acquisition unit 411 can be connected to the first signal transmitting end SO1 of the dual-channel microwave source 10 via a cable to acquire the modulation reference signal transmitted by the first signal transmitting end SO1. The first amplification unit 412 and the first filtering unit 413 amplify and filter the modulation reference signal in sequence and output it to the first receiving end IN3 of the processor 43. The receiving end of the second signal acquisition unit 421 can be connected to the receiving antenna 30 via a cable to acquire the modulation test signal at the receiving antenna 30. The second signal amplification unit 422 and the second filtering unit 423 amplify and filter the modulation test signal in sequence and output it to the second receiving end IN4 of the processor 43. Thus, the processor 43 can determine the moisture content of the wood 00 being tested based on the signals received by its first receiving end IN3 and second receiving end IN4.

[0062] Optional, see reference Figure 3 The wood moisture content detection device also includes a host computer 50; the host computer 50 is communicatively connected to the dual-channel microwave source 10; the host computer 50 is used to send microwave parameters to the dual-channel microwave source 10; the dual-channel microwave source 10 adjusts the frequency of the reference signal and the test signal according to the microwave parameters.

[0063] Specifically, the host computer 50 can communicate with the dual-channel microwave source 10 via a cable, so that the user can set the frequency of the microwave signal through the host computer 50.

[0064] Optional, continue to refer to Figure 3 The host computer 50 is also connected to the signal processing module 40; the signal processing module 40 is also used to send the moisture content to the host computer 50 after determining the moisture content of the wood being tested; the host computer 50 is also used to save the moisture content and display the moisture content.

[0065] Specifically, the host computer 50 can also communicate with the processor 43 in the signal processing module 40. After the processor 43 determines the moisture content of the wood 00 being tested based on the received reference signal and test signal, it can further send the calculated moisture content to the host computer 50. The host computer 50 can save the moisture content of the wood 00 being tested for later retrieval of the record, and can also display the current moisture content 00 so that the user can obtain the data in a timely manner.

[0066] In other embodiments of the present invention, the wood moisture content detection device may further include an isolating switch and a detector, each corresponding to a reference signal and a test signal, such as... Figure 3As shown, the wood moisture content detection device also includes a first isolating switch 61, a second isolating switch 62, a first detector 71, and a second detector 72. The first isolating switch 61 and the first detector 71 can be sequentially arranged between the first signal transmitting end SO1 of the dual-channel microwave source 10 and the receiving end of the first signal acquisition unit 411. The first isolating switch 61 is used to unidirectionally transmit the reference signal emitted by the dual-channel microwave source 10 to the subsequent circuit. The first detector 71 can demodulate the reference signal emitted by the dual-channel microwave source 10 to obtain the effective signal, so that the signal processing module 40 can directly process the demodulated effective signal. The second isolating switch 62 is located between the second signal transmitting end SO2 of the dual-channel microwave source 10 and the transmitting antenna 20; the second detector 72 can be located between the receiving antenna 30 and the receiving end of the second signal acquisition unit 421. The second isolating switch 62 is used to unidirectionally transmit the test signal emitted by the dual-channel microwave source 10 to the subsequent circuit. The second detector 72 can demodulate the received test signal to obtain the effective signal, so that the signal processing module 40 can directly process and calculate the demodulated effective signal, which can also improve the data processing efficiency.

[0067] Based on the same inventive concept, this invention also provides a method for detecting the moisture content of wood, which is executed using the wood moisture content detection device provided in any embodiment of this invention. Therefore, the wood moisture content detection method provided in this invention includes the technical features of the wood moisture content detection device provided in any embodiment of this invention, and can achieve the beneficial effects of the wood moisture content detection device provided in any embodiment of this invention. The similarities can be referred to the above description of the wood moisture content detection device provided in this invention, and will not be repeated here.

[0068] Optional, Figure 4 This is a flowchart of a method for detecting the moisture content of wood provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the method for detecting the moisture content of this wood includes:

[0069] S110, the signal processing module obtains the reference signal through the first receiving end.

[0070] S120, the signal processing module acquires the test signal through the second receiving end.

[0071] S130. Determine the moisture content of the wood being tested based on the reference signal and the test signal.

[0072] For details, please refer to Figure 1The first receiving terminal IN1 of the signal processing module 40 is communicatively connected to the first signal transmitting terminal SO1 of the dual-channel microwave source 10, thereby enabling it to receive the reference signal transmitted by the first signal transmitting terminal SO1 through the first receiving terminal IN1. The second signal transmitting terminal SO2 of the dual-channel microwave source 10 is communicatively connected to the transmitting antenna 20, which is positioned opposite to the receiving antenna 30, allowing the transmitting antenna 20 to radiate microwave signals to the receiving antenna 30. The receiving antenna 30 is communicatively connected to the second receiving terminal IN2 of the signal processing module 40, allowing the signal processing module 40 to acquire the test signal from the receiving antenna 30 through the second receiving terminal IN2. When the wood block 00 to be tested is placed between the transmitting antenna 20 and the receiving antenna 30, the signal radiated from the transmitting antenna 20 to the receiving antenna 30 is attenuated to a certain extent due to passing through the wood block 00, thereby enabling the detection of moisture content. The signal processing module can acquire multiple sets of reference signals and test signals, and can determine the microwave source error based on the multiple sets of reference signals, thereby eliminating the signal source error when calculating the moisture content and effectively improving the accuracy of wood moisture content detection.

[0073] The wood moisture content detection method provided in this invention embodiment, based on the wood moisture content detection device provided in this invention embodiment, employs a dual-channel microwave source to transmit two identical microwave signals. One microwave signal is used as a reference signal, and the other as a test signal. The reference signal and the test signal are set to be the same. When the wood to be tested is placed between the transmitting antenna and the receiving antenna, the signal radiated from the transmitting antenna to the receiving antenna is attenuated to a certain extent due to passing through the wood block being tested, thereby enabling the moisture content detection function. The signal processing module can acquire multiple sets of reference signals and test signals. Based on the multiple sets of reference signals, the microwave source error can be determined, thereby eliminating the signal source error when calculating the moisture content, effectively improving the accuracy of wood moisture content detection.

[0074] Optional, Figure 5 This is a flowchart of another method for detecting the moisture content of wood provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the method for detecting the moisture content of this wood includes:

[0075] S210, the signal processing module acquires the first reference signal emitted by the dual-channel microwave source when no wood under test is placed between the transmitting antenna and the receiving antenna through the first receiving end; and acquires the second reference signal emitted by the dual-channel microwave source when the wood under test is placed between the transmitting antenna and the receiving antenna.

[0076] S220: The signal processing module acquires the first test signal emitted by the dual-channel microwave source when no wood under test is placed between the transmitting antenna and the receiving antenna through the second receiving end; and acquires the second test signal emitted by the dual-channel microwave source when the wood under test is placed between the transmitting antenna and the receiving antenna.

[0077] S230. Determine the signal source error based on the first reference signal and the second reference signal.

[0078] S240. Determine the first attenuation value based on the first test signal and the second test signal.

[0079] S250. Based on a preset formula, the moisture content of the wood being tested is determined according to the signal source error and the first attenuation value.

[0080] Specifically, when detecting the moisture content of the wood 00 being tested, the signal processing module 40 first acquires the first reference signal M0 and the first test signal N0 when the antenna module is unloaded, i.e., when no wood 00 is placed between the transmitting antenna 20 and the receiving antenna 30. Then, the wood 00 is placed between the transmitting antenna 20 and the receiving antenna 30, and the signal processing module 40 acquires the reference signal and test signal at this time, i.e., the second reference signal M1 and the second test signal N1. The difference Q = M0 - M1 between the first reference signal M0 and the second reference signal M1 is then the error between the two received reference signals. The difference refers to the signal source error under load and no load. The first attenuation value V is the difference N1-N0 between the first test signal N0 and the second test signal N1. This includes the attenuation caused by the wood being tested, the attenuation caused by the moisture content in the wood being tested, and the signal source error Q. Therefore, subtracting the signal source error Q (VQ) from the difference V between the first test signal N0 and the second test signal N1 can eliminate the signal source error Q. Based on this, the moisture content of the wood being tested can be determined by combining the signal source error Q and the first attenuation value V with a preset formula. This eliminates the error caused by signal source fluctuations on the moisture content result and effectively improves the accuracy of wood moisture content detection.

[0081] For example, the default formula is: W = 20 * k * log 10 [(VQ) / N0]+b; where W is the actual moisture content of the wood being tested, V is the first attenuation value, Q is the signal source error, and k and b are constants.

[0082] Specifically, the above-mentioned preset formula can be derived from fitting multiple sets of test data. When conducting the test, the wood sample can be tested multiple times. The wood sample block can be placed in a vacuum drying oven to dry. The drying oven is adjusted to a suitable temperature to dry the wood. As its moisture content decreases, the temperature of the drying oven is gradually increased until the mass does not change significantly after several weighings. It can be determined that the wood sample has reached an absolutely dry state. The weight of the wood at this time can be used as the absolute dry value to calculate the actual moisture content W of the subsequent wood sample, so as to verify the moisture content measured by the wood moisture content detection device. When acquiring fitting data, the absolutely dry wood sample can be soaked in deionized water for a certain period of time. The actual moisture content W1 of the wood sample at this time is calculated by weighing. Then, it is placed between the transmitting antenna 20 and the receiving antenna 30 to obtain a set of reference signal M1 and test signal N1. Combined with the reference signal M0 and test signal N0 when the transmitting antenna 20 and the receiving antenna 30 are unloaded, the signal source error Q1 and the first attenuation value V1 are calculated. At this time, V1-Q1 can be regarded as the final attenuation value to eliminate the signal source error, and it is recorded as the first set of data. When acquiring the second set of data, the wood sample can be dried in a vacuum drying oven for a certain period of time. The actual moisture content W2 and the final attenuation value V2-Q2 are obtained in the same way. The above operation is repeated to obtain n sets of data, that is, to obtain multiple sets of (Wn, Vn-Qn) as natural numbers. Then, the actual moisture content W is used as the vertical axis and log[(VQ) / N0] is used as the horizontal axis to fit the test data. The fitting formula can be obtained as W=20*k*log 10 [(VQ) / N0]+b. Verification has shown that the logarithmic calculation method for the change in the test signal results in extremely small moisture content detection error and high measurement accuracy. Furthermore, the dual-channel microwave source detection device, which eliminates the error caused by signal source fluctuations in moisture content detection, further improves the accuracy of wood moisture content detection.

[0083] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0084] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A device for detecting the moisture content of wood, characterized in that, include: Dual-channel microwave source, transmitting antenna, receiving antenna, and signal processing module; The dual-channel microwave source includes a first signal transmitting end and a second signal transmitting end. The first signal transmitting end is communicatively connected to the first receiving end of the signal processing module, and the second signal transmitting end is communicatively connected to the transmitting antenna. The first signal transmitting end transmits a reference signal to the first receiving end of the signal processing module, and the second signal transmitting end transmits a test signal to the transmitting antenna. The wood to be tested is placed between the transmitting antenna and the receiving antenna, and the receiving antenna is communicatively connected to the second receiving end of the signal processing module. The receiving antenna is used to receive the test signal transmitted by the transmitting antenna; and to send the test signal to the second receiving end of the signal processing module; The signal processing module is used to determine the moisture content of the wood being tested based on the reference signal and the test signal; The reference signal includes a first reference signal when no wood under test is placed between the transmitting antenna and the receiving antenna, and a second reference signal when the wood under test is placed between the transmitting antenna and the receiving antenna; the test signal includes a first test signal when no wood under test is placed between the transmitting antenna and the receiving antenna, and a second test signal when the wood under test is placed between the transmitting antenna and the receiving antenna. The signal processing module is further configured to determine a signal source error based on the first reference signal and the second reference signal; determine a first attenuation value based on the first test signal and the second test signal; and determine the moisture content of the wood being tested based on a preset formula, the first attenuation value, and the signal source error; wherein the signal source error is the difference between the first reference signal and the second reference signal. The preset formula is: W=20*k*log 10 [(V-Q) / N0]+b Wherein, W is the actual moisture content of the wood being tested, V is the first attenuation value, Q is the signal source error, and k and b are constants.

2. The wood moisture content detection device according to claim 1, characterized in that, The signal processing module includes: a first signal processing module, a second signal processing module, and a processor; The receiving end of the first signal processing module is communicatively connected to the first signal transmitting end of the dual-channel microwave source, and the output end of the first signal processing module is electrically connected to the first input end of the processor; the first signal processing module is used to output a first processed signal to the processor according to the reference signal; The receiving end of the second signal processing module is communicatively connected to the receiving antenna, and the output end of the second signal processing module is electrically connected to the second input end of the processor; the second signal processing module is used to output a second processed signal to the processor according to the test signal; The processor is used to determine the moisture content of the wood being tested based on the first processing signal and the second processing signal.

3. The wood moisture content detection device according to claim 2, characterized in that, The dual-channel microwave source also includes a modulation signal receiver; The processor's communication connection is as follows: the modulation signal output terminal is electrically connected to the modulation signal receiving terminal of the dual-channel microwave source. The processor is also configured to provide a modulation signal of a preset frequency to the dual-channel microwave source, wherein the dual-channel microwave source generates a modulation reference signal based on the reference signal and the modulation signal, and transmits the modulation reference signal to the first signal processing module through the first signal transmitting end, and generates a modulation test signal based on the test signal and the modulation signal, and transmits the modulation test signal to the transmitting antenna through the second signal transmitting end.

4. The wood moisture content detection device according to claim 2, characterized in that, The first signal processing module includes: a first signal acquisition unit, a first signal amplification unit, and a first filtering unit; The receiving end of the first signal acquisition unit is communicatively connected to the first signal transmitting end of the dual-channel microwave source; the input end of the first signal amplification unit is electrically connected to the output end of the first signal acquisition unit, the output end of the first signal amplification unit is electrically connected to the input end of the first filtering unit, and the output end of the first filtering unit is electrically connected to the first receiving end of the processor. The second signal processing module includes: a second signal acquisition unit, a second signal amplification unit, and a second filtering unit; The receiving end of the second signal acquisition unit is communicatively connected to the receiving antenna; the input end of the second signal amplification unit is electrically connected to the output end of the second signal acquisition unit; the output end of the second signal amplification unit is electrically connected to the input end of the second filtering unit; and the output end of the second filtering unit is electrically connected to the second receiving end of the processor.

5. The wood moisture content detection device according to claim 1, characterized in that, Also includes: Host computer; The host computer is communicatively connected to the dual-channel microwave source. The host computer is used to send microwave parameters to the dual-channel microwave source; The dual-channel microwave source adjusts the frequencies of the reference signal and the test signal according to the microwave parameters.

6. The wood moisture content detection device according to claim 5, characterized in that, The host computer is also communicatively connected to the signal processing module; The signal processing module is also used to send the moisture content of the wood to the host computer after determining the moisture content of the wood being tested. The host computer is also used to save the moisture content and display the moisture content.

7. A method for detecting the moisture content of wood, performed using the wood moisture content detection device according to any one of claims 1 to 6, characterized in that, include: The signal processing module acquires the reference signal through the first receiving end; The signal processing module acquires the test signal through the second receiving end; The moisture content of the wood being tested is determined based on the reference signal and the test signal. The signal processing module acquires a reference signal through the first receiving end, including: acquiring a first reference signal emitted by the dual-channel microwave source when no wood to be tested is placed between the transmitting antenna and the receiving antenna; and acquiring a second reference signal emitted by the dual-channel microwave source when the wood to be tested is placed between the transmitting antenna and the receiving antenna. The signal processing module acquires test signals through the second receiving end, including: the signal processing module acquires a first test signal emitted by the dual-channel microwave source when no wood under test is placed between the transmitting antenna and the receiving antenna; and acquires a second test signal emitted by the dual-channel microwave source when wood under test is placed between the transmitting antenna and the receiving antenna. Determining the moisture content of the wood to be tested based on the reference signal and the test signal includes: determining a signal source error based on the first reference signal and the second reference signal; determining a first attenuation value based on the first test signal and the second test signal; and determining the moisture content of the wood to be tested based on a preset formula, the signal source error, and the first attenuation value; wherein the signal source error is the difference between the first reference signal and the second reference signal. The preset formula is: W=20*k*log 10 [(V-Q) / N0]+b Wherein, W is the actual moisture content of the wood being tested, V is the first attenuation value, Q is the signal source error, and k and b are constants.

Images