JP7267900B2 - Particulate matter measuring device, particulate matter measuring method, and particulate matter measuring program - Google Patents

Description

The present invention relates to a particulate matter measuring device, a particulate matter measuring method, and a particulate matter measuring program.

Diesel Particulate Filter (Diesel Particulate Filter) is inserted in the middle of the exhaust pipe leading from the engine to the atmosphere in a vehicle having a diesel engine, and collects particulate matter (hereinafter referred to as PM) contained in the exhaust gas. , hereinafter referred to as DPF).

When a large amount of collected PM accumulates in the DPF, it becomes difficult for the exhaust gas to flow, the exhaust pressure of the engine increases, and the engine characteristics deteriorate. Also, if too much PM builds up on the DPF, excessive heat will be generated during DPF regeneration, possibly damaging the filter. To prevent this, it is necessary to regenerate the DPF by injecting extra fuel to raise the temperature of the DPF and burning and removing the PM trapped in the DPF before the PM builds up too much. . However, if the DPF is regenerated more than necessary, extra fuel will be consumed and the fuel efficiency will deteriorate, so it is necessary to accurately measure the amount of accumulated PM.

US Pat. No. 6,200,000 describes a method for determining the clogging of filters with a first dielectric constant using materials with different dielectric constants.

Japanese Patent Application Publication No. 2012-507660

In the future, it is expected that the material of the DPF 20 will shift from cordierite, which is a dielectric, to silicon carbide, which is a conductor. Therefore, it is necessary to measure the amount of PM deposited on filters made of conductors as well. However, in the method of Patent Literature 1, when the filter is manufactured with a conductor having a high dielectric constant, the PM deposition amount cannot be measured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a particulate matter measuring apparatus capable of measuring the amount of deposited PM even when a filter made of a conductor is used.

A particulate matter measuring device according to the present invention includes a substantially cylindrical DPF that collects particulate matter contained in exhaust gas, and a substantially cylindrical housing that houses the DPF and whose both end surfaces are covered. , a housing having openings in each of the first surface and the second surface, which are both end surfaces, and an antenna provided inside the housing, wherein the first surface and the first surface of the DPF a sine wave generator that generates a reference sine wave that is a sine wave of a reference frequency; and a frequency sweep of the reference sine wave by an integer multiple. a sweeping unit that generates a microwave that has been generated and irradiates the microwave to the DPF via the antenna; a receiving unit that receives the reflected wave reflected by the DPF via the antenna; a reflected wave synthesizing unit for synthesizing reflected waves to calculate a square wave; an impedance measuring unit for calculating impedance from the reflected wave based on the square wave; the calculated impedance; calculating the amount of impedance change, which is the difference between the impedance calculated from the reflected wave in a state in which the particulate matter is not deposited, and calculating the amount of the particulate matter deposited on the DPF based on the amount of impedance change; and a quantity calculator.

According to the particulate matter measurement device according to the present invention, a DPF (Diesel Particulate Filter) is irradiated with a microwave obtained by sweeping the frequency of a reference sine wave by an integral multiple, and the impedance calculated from the reflected wave and the particles in the DPF The amount of change in impedance, which is the difference from the impedance calculated from the reflected wave in a state where no particulate matter is deposited, is calculated, and the amount of particulate matter deposited on the DPF is calculated based on the amount of impedance change. This makes it possible to measure the amount of deposited PM even when using a filter made of a conductor, that is, a material with a high dielectric constant.

Here, a deposition location calculation unit may be provided that calculates a deposition location where the particulate matter is deposited on the surface of the DPF based on the square wave.

a deposition distribution estimation unit for estimating the deposition distribution of the particulate matter in the DPF based on the deposition amount calculated by the deposition amount calculation unit and the deposition location calculated by the deposition location calculation unit; good too.

Here, the sine wave generator may calculate the frequency and amplitude of the reference sine wave based on the natural frequency of the DPF and the shape and capacity of the housing. As a result, it is possible to obtain the accumulated amount of particulate matter with high accuracy.

A particulate matter measuring method according to the present invention includes a substantially rod-shaped DPF that collects particulate matter contained in exhaust gas, and a substantially cylindrical housing that houses the DPF and whose end faces are covered, A housing having openings on each of the first surface and the second surface, which are both end surfaces, and an antenna provided inside the housing, wherein the first surface and the first surface of the DPF are provided. A particulate matter measuring method in which a particulate matter measuring device including a first end face that is an opposing end face and an antenna provided between a reference and a a step of generating a reference sine wave that is a sine wave of a frequency equal to the above; a step of generating a microwave obtained by sweeping the frequency of the reference sine wave by an integral multiple; and a step of irradiating the DPF with the microwave through the antenna a step of receiving a reflected wave reflected by the DPF via the antenna; a step of synthesizing the received reflected waves to calculate a square wave; calculating an impedance, and calculating an impedance change amount that is a difference between the calculated impedance and an impedance calculated from a reflected wave in a state where the particulate matter is not deposited on the DPF; and the impedance change. and calculating a deposition amount of the particulate matter deposited on the DPF based on the amount.

A particulate matter measurement program according to the present invention includes a substantially rod-shaped DPF that collects particulate matter contained in exhaust gas, and a substantially cylindrical housing that houses the DPF and whose end faces are covered, A housing having openings on each of the first surface and the second surface, which are both end surfaces, and an antenna provided inside the housing, wherein the first surface and the first surface of the DPF are provided. A particulate matter measurement program for controlling a particulate matter measurement device comprising: a first end face, which is an opposing end face; A sine wave generator that generates a certain reference sine wave, a sweeper that generates a microwave obtained by sweeping the frequency of the reference sine wave by an integral multiple, irradiates the microwave to the DPF via the antenna, and is reflected by the DPF a receiving unit for receiving the reflected wave through the antenna; a reflected wave synthesizing unit for synthesizing the received reflected waves to calculate a square wave; and calculating an impedance from the reflected wave based on the square wave. an impedance measuring unit for calculating an impedance change amount that is a difference between the calculated impedance and an impedance calculated from a reflected wave in a state where the particulate matter is not deposited on the DPF; and a deposition amount calculation unit that calculates the deposition amount of the particulate matter deposited on the DPF based on the DPF.

According to the present invention, the amount of deposited PM can be measured even when a filter made of a conductor is used.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the outline of the particulate matter measuring device 1 which concerns on this invention. 2 is a functional block diagram of the particulate matter measuring device 1; FIG. FIG. 4 is a diagram for explaining the processing of the reflected wave synthesizing unit 44 and the impedance measuring unit 45, (a) showing an example of a power spectrum showing the relationship between the frequency and signal strength of the microwave irradiated to the DPF 20, and (b) shows an example of a square wave generated from a reflected wave, and (c) shows an example of impedance obtained from the square wave. Fig. 2 is a graph showing the relationship between the PM deposition amount or deposition location and the square wave; (a) and (b) show the relationship between the PM deposition amount and the waveform; Show relationship between distance and waveform 4 is a flow chart showing a mechanism by which the particulate matter measuring device 1 calculates the deposition distribution of PM. 1 is a cross-sectional view showing an outline of a conventional particulate matter measuring device 100. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a particulate matter measuring device, a particulate matter measuring method, and a particulate matter measuring program according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an outline of a particulate matter measuring device 1 according to the present invention. The particulate matter measuring device 1 mainly includes a housing 10 , a diesel particulate filter 20 (hereinafter referred to as DPF 20 ), an antenna 30 and a computing section 40 .

The housing 10 is a substantially cylindrical housing with both end surfaces covered, and accommodates the DPF 20 therein. In a vehicle having a diesel engine, for example, the housing 10 constitutes part of an exhaust pipe leading from the engine to the atmosphere. The housing 10 has a first opening 13 and a second opening 14 on each of a first surface 11 and a second surface 12, which are both end surfaces. For example, the first opening 13 is connected with the engine and the second opening 14 is open to the atmosphere.

The DPF 20 is a filter that collects particulate matter contained in the exhaust gas, and has a substantially cylindrical shape. The DPF 20 is accommodated substantially in the longitudinal center of the housing 10 . The DPF 20 is mainly made of ceramic, for example, but in the present embodiment, the DPF 20 uses silicon carbide (SiC), which has high thermal conductivity, high strength, and high thermal shock resistance. Silicon carbide is a conductor. The DPF 20 is a honeycomb porous filter in which adjacent air holes are alternately closed, and the honeycomb pores trap PM contained in the exhaust gas.

The DPF 20 has a first end face 21 and a second end face 22, which are both end faces, the first end face 21 facing the first face 11 and the first opening 13, and the second end face 22 facing the second face 12 and the second end face 22. It faces the opening 14 . Exhaust gas that has flowed into the housing 10 through the first opening 13 enters the DPF 20 through the first end surface 21, where particulate matter (PM) is removed, passes through the second end surface 22, and enters the atmosphere through the second opening 14. released.

The antenna 30 is provided inside the housing 10 . Antenna 30 is arranged between first surface 11 and first end surface 21 . The antenna 30 converts an electric signal from the sweeping unit 42 (detailed later) into a microwave (detailed later), irradiates the microwave toward the DPF 20, and reflects the microwave from the DPF 20. The generated reflected wave (detailed later) is received, the reflected wave is converted into an electric signal, and transmitted to the receiving section 43 (detailed later).

In addition, the arrangement position of the antenna 30 is arbitrary, and the shape of the housing 10 is not limited to this. Moreover, the directivity of the antenna 30 is arbitrary, and may be, for example, omnidirectional, unidirectional, bidirectional, or the like. As will be described later, the particulate matter measurement device 1 obtains the amount of PM accumulated in the DPF 20 based on the change due to PM in the reflected wave received by the antenna 30, so it is sufficient if the state of change can be measured. .

FIG. 2 is a functional block diagram of the particulate matter measuring device 1. As shown in FIG. Antenna 30 is connected to arithmetic unit 40 via directional coupler 35 . The directional coupler 35 is a member that separates the microwave irradiated to the DPF 20 from the reflected wave. Therefore, one antenna 30 can be shared by the sweeping unit 42 and the receiving unit 43 . Note that the directional coupler 35 may be included in the antenna 30 .

The calculation unit 40 is connected to the antenna 30 and includes a calculation device such as a CPU (Central Processing Unit) for executing information processing, and a storage device such as a RAM (Random Access Memory) and a ROM (Read Only Memory). . The arithmetic device operates according to a program stored in the storage device. The program can be provided by downloading via a network, or can be provided by being recorded on various computer-readable recording media.

The calculation unit 40 mainly includes, as software resources, a sine wave generation unit 41, a sweep unit 42, a reception unit 43, a reflected wave synthesis unit 44, an impedance measurement unit 45, a PM accumulation amount calculation unit 46, a PM accumulation location calculation unit 47, and a PM deposition distribution estimating unit 48 .

The sine wave generator 41 generates a sine wave of a reference frequency (hereinafter referred to as a reference sine wave). Although the frequency band of the reference sine wave is not limited, it may be, for example, the 2.5 MHz band. Also, the amplitude of the reference sine wave is arbitrary.

However, the sine wave generator 41 preferably calculates the frequency and amplitude of the reference sine wave based on the natural frequency of the DPF 20 and the shape and capacity of the housing 10 in order to improve accuracy. For example, the frequency and amplitude of the reference sine wave can be calculated from the natural frequency of the DPF 20 and the shape and capacity of the housing 10 using three-dimensional electromagnetic field analysis. Various known methods can be used for the three-dimensional electromagnetic field analysis.

The sweep unit 42 generates microwaves obtained by sweeping the frequency of the reference sine wave by integral multiples. The frequency of the sine wave emitted by the sweeping unit 42 is, for example, twice, eight times, or sixteen times the reference frequency, but is not limited thereto. The greater the number of types of frequencies to be swept, the higher the measurement accuracy, but the higher the processing load. The most efficient value can be calculated using three-dimensional electromagnetic field analysis.

Also, the sweep unit 42 irradiates the generated microwave to the DPF 20 via the directional coupler 35 and the antenna 30 . The irradiated microwave is reflected by the DPF 20 .

The receiving unit 43 receives the reflected wave reflected by the DPF 20 via the antenna 30 . Since the directional coupler 35 is provided, the reflected wave is separated from the microwave irradiated to the DPF 20 and received by the receiving section 43 . The reflected wave has a waveform that is attenuated or delayed by the DPF 20 and PM compared to the irradiated microwave (detailed later).

The reflected wave synthesizing unit 44 synthesizes the reflected waves received by the receiving unit 43 to calculate a square wave. Specifically, the reflected wave synthesizing unit 44 calculates a square wave by inverse Fourier transforming the power spectrum of the microwaves received in a predetermined time range.

The impedance measurement unit 45 calculates impedance from the reflected wave based on the square wave.

3A and 3B are diagrams for explaining the processing of the reflected wave synthesizing unit 44 and the impedance measuring unit 45. FIG. 3A shows an example of the power spectrum showing the relationship between the frequency of the microwave irradiated to the DPF 20 and the signal strength. , (b) shows an example of a square wave generated from a reflected wave, and (c) shows an example of impedance obtained from the square wave.

As shown in FIG. 3(a), the DPF 20 is irradiated with a reference frequency f and a microwave having a frequency that is an integral multiple of the reference frequency f. The signal of the reference frequency f is larger, and the signal becomes smaller as the microwave frequency increases.

When the reflected wave is subjected to inverse Fourier transform, a square wave shown in FIG. 3(b) is calculated. The square wave is deformed according to the amount of deposited PM and the like (detailed later).

Impedance analysis of the square wave shown in FIG. 3(b) yields the impedance graph shown in FIG. 3(c). Impedance analysis can use various known methods.

Returning to the description of FIG. The impedance measurement unit 45 can observe the change in impedance according to the distance from the antenna 30 by calculating the square wave. Since the distance from the predetermined measurement point on the first end surface 21 to the antenna 30 is known in advance, the impedance measurement unit 45 measures the reflected wave reflected at the measurement point on the first end surface 21 among all the reflected waves. can only be extracted. Then, the impedance measurement unit 45 calculates the change in impedance from the reflected wave reflected at the measurement point on the first end face 21, thereby excluding the influence of the unintended reflected wave inside the housing 10. .

The PM deposition amount calculation unit 46 calculates an impedance change amount, which is the difference between the impedance measured by the impedance measurement unit 45 and the impedance calculated from the reflected wave of the DPF 20 on which PM is not deposited, and calculates the calculated impedance The amount of PM deposited on the DPF 20 is calculated based on the amount of change.

The PM deposition amount calculator 46 holds the impedance when PM is not deposited (hereinafter referred to as initial impedance). As for the initial impedance, the sine wave generator 41 generates a reference sine wave, the sweeper 42 generates a microwave obtained by sweeping the frequency of the reference sine wave by an integral multiple, and irradiates the DPF 20 on which PM is not deposited. The reception unit 43 receives the reflected wave reflected by the DPF 20 that is not deposited, the reflected wave synthesizing unit 44 synthesizes the reflected waves received by the reception unit 43 to calculate a square wave, and the impedance measurement unit 45 It is obtained by calculating the impedance from the wave.

Then, the PM deposition amount calculation unit 46 calculates the difference between the impedance measured by the impedance measurement unit 45 and the initial impedance as an impedance change amount.

In addition, the PM deposition amount calculator 46 calculates the deposition amount of PM deposited on the DPF 20 (hereinafter referred to as PM deposition amount) based on the impedance change amount. The PM deposition amount calculator 46 holds information indicating the relationship between the impedance change amount and the PM deposition amount. There is a proportional relationship (linear distribution) between the amount of change in impedance and the amount of deposited PM, and the greater the impedance, the greater the amount of deposited PM. The PM deposition amount calculation unit 46 stores in advance a relational expression between the impedance change amount and the PM deposition amount, and calculates the PM deposition amount on the surface of the DPF 20 from the impedance change amount by performing calculation using the relational expression. calculate.

The PM deposition location calculator 47 calculates the deposition location where PM is deposited on the surface of the DPF 20 based on the square wave generated by the reflected wave synthesis unit 44 .

FIG. 4 is a graph showing the relationship between the PM deposition amount or deposition location and the square wave. It shows the relationship between the distance from the antenna 30 and the waveform. A rectangular wave s1 in FIGS. 4A to 4C is an ideal rectangular wave generated based on the reflected wave of the DPF 20 when PM is not deposited.

The shape of the square wave received by the receiver 43 varies depending on the PM deposition distribution on the DPF 20 . As shown by the square waves r1 and r2 in FIG. 4A, when PM accumulates, the rise of the square wave becomes dull (the rise becomes gentle). Also, when PM accumulates, the peak voltage of the square wave increases or decreases, as shown by the square waves r1 and r2 in FIG. 4(a). For example, if the impedance of the deposited PM is greater than the impedance of the DPF 20 in its initial state, the peak voltage of the square wave increases. Also, for example, when the impedance of the deposited PM is smaller than the impedance of the DPF 20 in the initial state, the peak voltage of the square wave decreases.

In addition, as the PM accumulates on the surface of the DPF 20, the distance from the antenna 30 to the accumulation position of PM becomes shorter. Therefore, as shown by the square wave r3 in FIG. 4B, the rise of the square wave advances.

Further, when the distance between the antenna 30 and the DPF 20 is different, the phase of the square wave is shifted. Further, when the distance from the antenna 30 to the deposition position of PM increases, the rise of the square wave is delayed as shown by the square wave r4 in FIG. 4(c). In practice, changes in the waveforms schematically shown in FIGS. 4(a) to 4(c) occur in a complex manner.

Returning to the description of FIG. In addition, the PM deposition location calculation unit 47 creates a model in advance, and in a state where PM is not deposited on the DPF 20, for each irradiation frequency, each measurement point on the first end surface 21 by the method described above. The impedance is calculated from the reflected wave from and stored as a reference value. The PM deposition location calculator 47 can identify each measurement point based on the difference in distance from the antenna 30 . In addition, because the shape inside the housing 10 is non-uniform, the transmission paths of the irradiated waves and the reflected waves are different. The measurement point can be identified from the difference in At this time, by sweeping and irradiating a plurality of frequencies, it becomes easier to determine the measurement point.

The PM deposition distribution estimation unit 48 estimates the PM deposition distribution in the DPF 20 based on the deposition amount calculated by the PM deposition amount calculation unit 46 and the deposition location calculated by the PM deposition location calculation unit 47 .

It should be noted that the deposition amount inside the DPF 20 cannot be measured directly. However, the shape of the DPF 20 is uniform, and the deposition amount and its position on the surface of the DPF 20 can be calculated as already described. Therefore, the PM deposition distribution estimator 48 can estimate the PM deposition distribution inside the DPF 20 , that is, the entire DPF 20 from the deposition distribution on the surface of the DPF 20 .

It should be noted that the configuration of the computing unit 40 shown in FIG. 2 has been described as the main configuration in describing the features of the present embodiment, and does not exclude, for example, the configuration provided in a general information processing apparatus. The components of the computing unit 40 may be classified into more components depending on the processing content, or one component may perform the processing of a plurality of components.

FIG. 5 is a flow chart showing a mechanism by which the particulate matter measurement device 1 calculates the deposition distribution of PM.

First, the sine wave generator 41 generates a sine wave (reference sine wave) of a reference frequency f (step S1). Then, the sweep unit 42 sweeps the frequency of the reference frequency f by an integral multiple (step S2). Further, the sweep unit 42 irradiates the DPF 20 from the antenna 30 with the reference frequency f and a sine wave having a frequency that is an integral multiple of the reference frequency f via the directional coupler 35 (step S2).

Next, the receiver 43 receives a reflected wave of the microwave emitted from the antenna 30 to the DPF 20 and reflected by the DPF 20 via the antenna 30 and the directional coupler 35 (step S3).

Next, the reflected wave synthesizing unit 44 generates a square wave by synthesizing the reflected waves and performing inverse Fourier transform (step S4). The impedance measurement unit 45 performs impedance analysis on the square wave generated in step S4 and measures the impedance calculated from the reflected wave (step S5).

The PM accumulation amount calculator 46 calculates the difference between the impedance calculated in step S5 and the initial impedance as the impedance change amount, and calculates the PM accumulation amount in the DPF 20 based on the impedance change amount (step S6). In addition, the PM deposition location calculator 47 calculates the PM deposition location on the surface of the DPF 20 based on the amount of impedance change (step S6). The calculation of the amount of deposited PM and the calculation of the deposition location of PM may be performed in order (in no particular order) or may be performed simultaneously.

Next, the PM deposition distribution estimator 48 estimates the deposition distribution of the entire PM on the DPF 20 based on the PM deposition amount and deposition location calculated in step S6 (step S7).

The calculation unit 40 determines whether or not an instruction to end the process has been input (step S8). An instruction to end the process may be input to the calculation unit 40 from an input device (not shown) or the like, or may be calculated from a control unit (not shown) that controls the internal combustion engine at the same time that the internal combustion engine is stopped. It may be input to section 40 .

If an instruction to end the process has not been input (NO in step S8), the calculation unit 40 returns the process to step S1. If an instruction to end the process has been input (YES in step S8), the calculation unit 40 ends the series of processes. That is, the calculation unit 40 continuously performs the processing shown in FIG. By continuously measuring the change in impedance in this manner, the change in the amount of PM accumulated in the DPF 20 can be measured. As a result, the deposition distribution of PM can be accurately estimated.

According to the present embodiment, since the amount of deposited PM is calculated using the reflected wave, the amount of deposited PM and the deposition distribution of PM can be obtained even when a filter made of a conductor is used.

For example, in the method that utilizes the transmission characteristics of microwaves, the deposition amount of PM cannot be calculated in the case of the DPF 20 made of a conductor such as silicon carbide that is difficult to transmit microwaves, that is, a material with a high dielectric constant. .

On the other hand, in the present embodiment, since the reflected wave from the DPF 20 is used, even if the DPF 20 is made of a conductor that reflects microwaves, that is, a substance with a high dielectric constant, the deposition amount of PM can be accurately estimated. be able to. In particular, since silicon carbide is excellent in thermal conductivity, by using the DPF 20 made of silicon carbide, both thermal conductivity and highly accurate PM deposition distribution estimation can be achieved.

Further, according to the present embodiment, since the reflected wave is used to calculate the PM deposition amount, only one antenna 30 is required, and the PM deposition amount can be measured with a simple configuration.

FIG. 6 is a cross-sectional view showing an outline of a conventional particulate matter measuring device 100. As shown in FIG. In the particulate matter measuring device 100, a transmitting antenna 130a is arranged on the first end face 21 side of the DPF 20, and a receiving antenna 130b is arranged on the second end face 22 side. That is, the microwave transmitted from the antenna 130a and transmitted through the DPF 20 is received by the antenna 130b, and the calculation device 140 analyzes the received microwave to estimate the deposition amount of PM.

However, since the particulate matter measuring apparatus 100 obtains the amount of deposited PM from the transmission characteristics of microwaves, two antennas 130a and 130b are required before and after the DPF 20, and in consideration of the transmission characteristics of microwaves, Antennas 130a, 130b must be placed in the appropriate locations.

In addition, in the particulate matter measurement device 100, in order to measure the bias of PM deposition in the DPF 20, the directivity of the antennas 130a and 130b is increased, and then the antennas 130a and 130b are made movable, or a plurality of antennas 130a, 130b must be installed.

On the other hand, in the present embodiment, since the amount of accumulated PM is obtained based on the amount of change in impedance calculated from the reflected wave, only one antenna 30 is required, and there are no restrictions on the placement and directivity of the antenna. Further, in the present embodiment, the PM deposition distribution of the entire DPF 20 can be estimated by one-time microwave irradiation without spatially dividing the lateral region.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes and the like are also included within the scope of the gist of the present invention. .

Reference Signs List 1: particulate matter measuring device 10: housing 11: first surface 12: second surface 13: first opening 14: second opening 20: DPF (diesel particulate filter)
21 : first end surface 22 : second end surface 30 : antenna 35 : directional coupler 40 : calculation unit 41 : sine wave generation unit 42 : sweep unit 43 : reception unit 44 : reflected wave synthesis unit 45 : impedance measurement unit 46 : PM deposition amount calculation unit 47: PM deposition location calculation unit 48: PM deposition distribution estimation unit 100: Particulate matter measuring devices 130a and 130b: Antenna 140: Arithmetic device

Claims (6)

a substantially cylindrical DPF that collects particulate matter contained in exhaust gas;
a substantially cylindrical housing having both end faces covered for housing the DPF, the housing having openings in each of the first and second faces, which are the end faces;
an antenna provided inside the housing, the antenna disposed between the first surface and a first end surface of the DPF that is an end surface facing the first surface;
a sine wave generator that generates a reference sine wave that is a sine wave of a reference frequency;
a sweeping unit that generates a microwave obtained by sweeping the frequency of the reference sine wave by an integral multiple, and irradiates the DPF with the microwave through the antenna;
a receiving unit that receives the reflected wave reflected by the DPF via the antenna;
a reflected wave synthesizing unit that performs an inverse Fourier transform on the power spectrum of the received reflected wave;
an impedance measuring unit that calculates impedance based on the result of calculation by the reflected wave synthesizing unit ;
calculating an impedance change amount that is a difference between the calculated impedance and an impedance calculated from a reflected wave in a state in which the particulate matter is not deposited on the DPF; a deposition amount calculation unit that calculates the deposition amount of the deposited particulate matter;
A particulate matter measuring device comprising: 2. The particulate matter according to claim 1, further comprising a deposition location calculator that calculates a deposition location where the particulate matter is deposited on the surface of the DPF based on the result of the inverse Fourier transform. measuring device. A deposition distribution estimation unit for estimating the deposition distribution of the particulate matter in the DPF based on the deposition amount calculated by the deposition amount calculation unit and the deposition location calculated by the deposition location calculation unit. The particulate matter measuring device according to claim 2. 4. The sine wave generator according to any one of claims 1 to 3, wherein the sine wave generator calculates the frequency and amplitude of the reference sine wave based on the natural frequency of the DPF and the shape and capacitance of the housing. The particulate matter measurement device according to any one of items. a substantially rod-shaped DPF that collects particulate matter contained in the exhaust gas;
a substantially cylindrical housing having both end surfaces covered for accommodating the DPF, the housing having openings in each of the first and second surfaces, which are the both end surfaces;
an antenna provided inside the housing, the antenna provided between the first surface and a first end surface of the DPF that is an end surface facing the first surface ;
A particulate matter measuring method in which a particulate matter measuring device comprising a
generating a reference sine wave that is a sine wave at a reference frequency;
generating microwaves obtained by sweeping the frequency of the reference sine wave by integer multiples;
irradiating the DPF with the microwave through the antenna;
a step of receiving a reflected wave reflected by the DPF via the antenna;
inverse Fourier transforming the power spectrum of the received reflected wave;
Impedance is calculated based on the result of the inverse Fourier transform , and the impedance change is the difference between the calculated impedance and the impedance calculated from the reflected wave in a state where the particulate matter is not deposited on the DPF. calculating the amount;
calculating a deposition amount of the particulate matter deposited on the DPF based on the impedance change amount;
A particulate matter measuring method, comprising: a substantially rod-shaped DPF that collects particulate matter contained in the exhaust gas;
a substantially cylindrical housing having both end surfaces covered for accommodating the DPF, the housing having openings in each of the first and second surfaces, which are the both end surfaces;
an antenna provided inside the housing, the antenna provided between the first surface and a first end surface of the DPF that is an end surface facing the first surface ;
A particulate matter measurement program for controlling a particulate matter measurement device comprising
the computer,
a sine wave generator that generates a reference sine wave that is a sine wave with a reference frequency;
a sweeping unit that generates a microwave obtained by sweeping the frequency of the reference sine wave by an integral multiple, and irradiates the DPF with the microwave through the antenna;
a receiving unit that receives the reflected wave reflected by the DPF via the antenna;
a reflected wave synthesizing unit that performs an inverse Fourier transform on the power spectrum of the received reflected wave;
Impedance is calculated based on the calculation result by the reflected wave synthesizing unit , and the difference between the calculated impedance and the impedance calculated from the reflected wave in a state where the particulate matter is not deposited on the DPF. an impedance measurement unit that calculates the amount of impedance change;
a deposition amount calculation unit that calculates a deposition amount of particulate matter deposited on the DPF based on the impedance change amount;
A particulate matter measurement program characterized by functioning as

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