JP2021050930A - Data processing device - Google Patents

Abstract

To suppress an output value having a variation of a sensor from being stored in a storage section.SOLUTION: A control device includes: an output value acquisition section 122 which sequentially acquires an output value of a quality sensor 45 arranged in an exhaust emission control system which purifies exhaust gas flowing in an exhaust passage for each first cycle; a storage control section 123 which sequentially stores a predetermined calculated value obtained from a plurality of output values acquired during a second cycle longer than the first cycle in a storage section 110; a parameter acquisition section 125 which acquires an influence parameter which affects the output of the quality sensor 45 during one second cycle; and a data processing section 125 which deletes the calculated value stored in the storage section 110 during one second cycle when the acquired influence parameter satisfies a predetermined condition which indicates the variation in the output of the quality sensor 45.SELECTED DRAWING: Figure 2

Description

The present invention relates to a data processing device that stores a sensor output value in a storage unit.

The vehicle is equipped with an exhaust purification system that injects a reducing agent into the exhaust passage through which the exhaust gas flows in order to purify NOx (nitrogen oxides) in the exhaust gas of the engine. Further, the exhaust gas purification system is provided with various sensors (for example, a sensor for detecting a reducing agent, a sensor for detecting NOx, etc.), and an output value which is a detection value of the sensor is sequentially stored in a storage unit. There is.

Japanese Unexamined Patent Publication No. 2010-223650

By the way, the output value of the sensor may vary depending on the usage condition of the vehicle, the surrounding environment, and the like. It is possible to consider a measure to interrupt the storage of the output value of the sensor in the storage unit when an abnormality is detected, but the output value having a variation before the abnormality is detected is stored in the storage unit.

Therefore, the present invention has been made in view of these points, and an object of the present invention is to prevent the output values having variations in the sensor from being stored in the storage unit.

In one aspect of the present invention, the output value acquisition unit that sequentially acquires the output value of the sensor provided in the exhaust gas purification system that purifies the exhaust gas flowing through the exhaust passage in each first cycle, and the output value acquisition unit, and the first cycle A storage control unit that sequentially stores predetermined calculated values obtained from a plurality of the output values acquired during the long second cycle in the storage unit, and the output of the sensor during the first second cycle. When the parameter acquisition unit for acquiring the influence parameter having an influence and the acquired influence parameter satisfy a predetermined condition indicating the variation in the output of the sensor, they are stored in the storage unit during the first second cycle. Provided is a data processing apparatus including a data processing unit for deleting the calculated value.

Further, the data processing unit stores the calculated value stored in the storage unit during the first second cycle in the storage unit during the second cycle immediately before the first second cycle. It may be overwritten with the calculated value.

Further, the output value acquisition unit may sequentially acquire the output value of the reducing agent sensor provided in the accommodating unit accommodating the reducing agent that purifies the exhaust gas in each of the first cycles.

Further, the parameter acquisition unit acquires the temperature of the reducing agent as the influence parameter, and the data processing unit obtains the temperature change of the acquired reducing agent when the temperature change of the acquired reducing agent is larger than a predetermined degree, the first second cycle. The calculated value stored in the storage unit may be deleted during the period.

Further, the sensor is a heat conduction type sensor, and when the data processing unit detects that the key of the vehicle equipped with the exhaust purification system is turned on, it is stored in the storage unit during the first second cycle. The stored calculated value may be deleted.

According to the present invention, it is possible to suppress the storage of various output values of the sensor in the storage unit.

It is a schematic diagram which shows the structure of the exhaust gas purification system S which concerns on one Embodiment. It is a block diagram which shows the detailed structure of the control device 100. It is a schematic diagram for demonstrating the output value of a quality sensor 45. It is a schematic diagram for demonstrating the overwriting of the calculated value.

<Structure of exhaust purification system>
The configuration of the exhaust gas purification system S according to the embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a schematic view showing a configuration of an exhaust gas purification system S according to an embodiment. As shown in FIG. 1, the exhaust purification system S includes an engine 10, an exhaust passage 20, a DPF (Diesel Particulate Filter) 30, a urea water injection device 40, and an SCR (Selective Catalytic Reduction) device 50. , The NOx sensors 60 and 65, and the control device 100. The exhaust gas purification system S is mounted on a vehicle such as a truck and purifies the exhaust gas of the engine 10. Here, the exhaust purification system S purifies the exhaust gas flowing through the exhaust passage 20 with urea water which is a reducing agent.

The engine 10 is an internal combustion engine that generates power by burning and expanding a mixture of fuel and intake air (air). The engine 10 is a 4-cylinder diesel engine here, but the engine 10 is not limited to this, and may be an engine other than the 4-cylinder engine.

The exhaust passage 20 is an exhaust pipe connected to the engine 10 and exhausts the exhaust gas of the engine 10 to the outside of the vehicle. The exhaust passage 20 through which the exhaust gas flows is provided with a DPF 30, a urea water injection device 40, and an SCR device 50.

The DPF 30 is a filter that collects particulate matter (PM) contained in the exhaust gas. The DPF 30 is made of, for example, a honeycomb body made of metal or ceramics.

The urea water injection device 40 is provided between the DPF 30 and the SCR device 50, and injects urea water into the exhaust passage 20. The urea water injected by the urea water injection device 40 is hydrolyzed by the heat of the exhaust gas flowing through the exhaust passage 20 to generate ammonia. Ammonia is used to cause a reduction reaction of NOx in the exhaust gas. As shown in FIG. 1, the urea water injection device 40 includes an injection unit 41, a tank 42, a supply pipe 43, a pump 44, and a quality sensor 45.

The injection unit 41 injects urea water into the exhaust passage 20. The tank 42 is an accommodating portion for accommodating urea water. The supply pipe 43 is a pipe connecting the tank 42 and the injection unit 41, and is a flow path through which urea water flows. The pump 44 is a delivery unit that sends out urea water from the tank 42 toward the injection unit 41. The pump 44 is provided in the middle of the supply pipe 43.

The quality sensor 45 is a sensor for determining whether or not there is an abnormality in the quality of the urea water in the tank 42. The quality sensor 45 is provided in the tank 42 and detects, for example, the concentration of urea water. When the concentration is lower than the predetermined value, it can be determined that the tank 42 contains water or the like and the quality is abnormal. In addition to the quality sensor 45, a sensor for detecting the temperature and water level of urea water is provided in the tank 42.

The SCR device 50 is a device that converts NOx in the exhaust gas into harmless nitrogen by a reduction reaction. The SCR device 50 has a reduction catalyst 52 that promotes a reduction reaction between ammonia and NOx. Ammonia generated from urea water is adsorbed on the reduction catalyst 52. The reduction catalyst 52 reduces NOx to nitrogen and water by adsorbed ammonia, and reduces NOx emissions.

The NOx sensors 60 and 65 detect the concentration of NOx in the exhaust gas. The NOx sensor 60 is provided on the upstream side of the SCR device 50 in the exhaust passage 20, and the NOx sensor 65 is provided on the downstream side of the SCR device 50.

The control device 100 controls the operation of the exhaust gas purification system S. In the present embodiment, the control device 100 has a function of a data processing device that stores the output values of the output sensors (quality sensors 45, NOx sensors 60, 65, etc.) of the exhaust gas purification system S in the storage unit. Although the details will be described later, the control device 100 acquires the influence parameter during the detection of the output sensor and controls so that the output value having a variation of the output sensor is not stored in the storage unit.

<Detailed configuration of control device>
An example of the detailed configuration of the control device 100 will be described with reference to FIG.
FIG. 2 is a block diagram showing a detailed configuration of the control device 100. The control device 100 has a storage unit 110 and a control unit 120.

The storage unit 110 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 110 stores programs and various data for execution by the control unit 120. For example, the storage unit 110 stores the output value of the output sensor.

The control unit 120 is, for example, a CPU (Central Processing Unit). The control unit 120 controls the operation of the exhaust gas purification system S by executing the program stored in the storage unit 110. In the present embodiment, the control unit 120 functions as an output value acquisition unit 122, a storage control unit 123, a parameter acquisition unit 124, and a data processing unit 125.

The output value acquisition unit 122 acquires the output value of the output sensor provided in the exhaust gas purification system S. Hereinafter, as the output sensor, the quality sensor 45 of the urea water injection device 40 will be described as an example. The output value acquisition unit 122 acquires the output value of the quality sensor 45 during the operation of the exhaust gas purification system S.

FIG. 3 is a schematic diagram for explaining the output value of the quality sensor 45. As shown in FIG. 3, the output value acquisition unit 122 sequentially acquires the output values A1, A2, ..., An of the quality sensor 45 for each first cycle T1. For example, the interval between the time t1 at which the output value A1 is acquired and the time t2 at which the output value A2 is acquired is the first period T1.

The storage control unit 123 controls the storage of the output value of the quality sensor 45 in the storage unit 110. Here, the storage control unit 123 obtains a predetermined calculated value from a plurality of output values acquired during the second cycle T2, which is longer than the first cycle T1, and sequentially stores the obtained calculated value in the storage unit 110. .. The second cycle T2 indicates a time longer than twice the time of the first cycle T1. For example, the storage control unit 123 stores the average value of a plurality of output values in the storage unit 110 as a calculated value. In the above, the average value of the output values is stored in the storage unit 110, but the present invention is not limited to this, and for example, the storage control unit 123 may store the output value in the storage unit 110 as it is.

Here, it will be described with reference to FIG. Since the second cycle T2 is four times as long as the first cycle T1 here, four output values are acquired during the second cycle T2. Then, the storage control unit 123 stores the average value of the acquired four output values in the storage unit 110. For example, the storage control unit 123 stores the average value B1 of the output values A1, A2, A3, and A4, the average value B2 of the output values A5, A6, A7, and A8 in the storage unit 110. The storage control unit 123 may store the average value of the output values A2, A3, A4, and A5 in the storage unit 110 next to the average value B1. That is, the storage control unit 123 may store the moving average value of the output value in the storage unit 110.

The parameter acquisition unit 124 acquires influence parameters that affect the output of the quality sensor 45 during the second cycle T2. The parameter acquisition unit 124 acquires the influence parameter from the detection result of the detector group 70.

The parameter acquisition unit 124 acquires the temperature of urea water as an influence parameter. That is, the parameter acquisition unit 124 acquires the temperature of the urea water in the tank 42. The temperature of the urea water in the tank 42 is detected by a temperature sensor provided in the tank 42.

The data processing unit 125 performs various processes related to the exhaust gas purification system S based on the data stored in the storage unit 110 (for example, the calculated value described above). Further, the data processing unit 125 performs processing related to the data stored in the storage unit 110. In the present embodiment, when the influence parameter acquired during the first second cycle T2 satisfies a predetermined condition indicating the variation in the output of the sensor, the data processing unit 125 during the first second cycle T2. The calculated value stored in the storage unit 110 is deleted. For example, the data processing unit 125 averages the output values A1 to A4 when the influence parameters acquired during the acquisition of the output values A1 to A4 shown in FIG. 3 satisfy a predetermined condition indicating the variation in the output of the sensor. Delete the value B1.

The detection accuracy of the quality sensor 45 is usually better when the temperature of the urea water in the tank 42 is constant. In particular, when the quality sensor 45 is of the heat conduction type, the above characteristics are likely to be exhibited. Therefore, if the temperature of the urea water changes during detection, the detection accuracy of the quality sensor 45 will vary. The reason why the temperature of the urea water in the tank 42 changes is that when the tank 42 is replenished with urea water, when a part of the urea water supplied to the injection unit 41 returns to the tank 42 without being injected, it is outside. For example, when the temperature changes.

Therefore, in the present embodiment, if there is a temperature change of the urea water when the quality sensor 45 outputs the output value to the storage unit 110, the output value output during the temperature change is deleted. Specifically, when the temperature change of the urea water acquired during the first second cycle T2 is larger than a predetermined degree, the data processing unit 125 sends the storage unit 110 during the first second cycle T2. Delete the stored calculated value (for example, the average value of the output values). As a result, the calculated value calculated from the variable output value can be deleted from the storage unit 110.

Further, when the quality sensor 45 is of the heat conduction type, the cycle of heating in the heating section and detecting heat transfer in the heat receiving section is repeated due to its characteristics. Therefore, if the key (ignition key of the vehicle) is turned off and the key is turned on in the middle of this cycle, the following problems occur. That is, the heating by the heating part is interrupted by the key-off, and by the key-on immediately after that, the heat receiving part detects the heat transfer from the state where the heat in the middle of heating remains to the state where it is further heated, and the detection accuracy is greatly improved. Decreases to. Therefore, when the key on is detected, the data processing unit 125 calculates the calculated value stored in the storage unit 110 immediately after the key is turned on (that is, the average value of the output values of the quality sensor 45 immediately after the key is turned on). It may be deleted from the storage unit 110.

In the above description, the case where the quality sensor 45 is of the heat conduction type has been described, but the present invention is not limited to this, and for example, the quality sensor 45 may be of the ultrasonic type. In the case of the ultrasonic quality sensor 45, if bubbles are generated in the urea water in the tank 42, the detection accuracy of the quality sensor 45 drops. As a factor for generating bubbles, when the temperature of the urea water is in the temperature range in which bubbles are likely to be generated, a part of the urea water supplied to the injection unit 41 is not injected and returns to the tank 42. .. Therefore, when the data processing unit 125 tends to generate bubbles in the urea water, the data processing unit 125 similarly deletes the calculated value stored in the storage unit 110.

The data processing unit 125 uses the calculated value stored in the storage unit 110 during the first second cycle T2 as the calculated value stored in the storage unit 110 during the second cycle immediately before the first second cycle. Overwrite. As a result, the storage unit 110 stores the calculated value obtained from the output value without variation.

FIG. 4 is a schematic diagram for explaining overwriting of the calculated value. As shown in FIG. 4A, it is assumed that the calculated values B1, B2, B3, and B4 obtained for each second cycle T2 are sequentially stored in the storage unit 110. Here, it is assumed that there is no variation in the output values for calculating the calculated values B1 to B3, and that there is a variation in the output values for calculating the calculated values B4. Therefore, as shown in FIG. 4B, the data processing unit 125 overwrites the calculated value B4 with the immediately preceding calculated value B3.

In the above description, the storage control unit 123 stores the average value of the output values of the quality sensor 45 in the storage unit 110 as a calculated value, but the present invention is not limited to this. For example, the storage control unit 123 may store a coefficient and a limiter correction value when performing a specific process (for example, a digital filter process) on the output value of the quality sensor 45. The above coefficient is obtained from, for example, the sampling period and the cutoff frequency in a low-pass filter in order to remove electrical noise and the like. The limiter correction value is, for example, the maximum concentration change amount when water is replenished in the tank 42, which is obtained from the remaining amount of urea water in the tank 42 and the capacity of the tank 42. When the output of the quality sensor 45 varies, the data processing unit 125 deletes the above-mentioned coefficient and limiter correction value stored in the storage unit 110.

Further, in the above description, the quality sensor 45 has been described as an example of the output sensor, but the NOx sensor 65 may be used, for example. The NOx sensor 65 usually detects oxygen decomposed from NOx internally. On the other hand, if the temperature in the exhaust passage 20 rises and cannot be completely purified by the reduction catalyst 52, the ammonia separated from the reduction catalyst 52 may be detected by the NOx sensor 65, resulting in variations in output. is there.

Further, in the above, when the influence parameter satisfies a predetermined condition indicating the variation of the output of the sensor, the data processing unit 125 deletes the calculated value stored in the storage unit 110 during the first second cycle T2. However, it is not limited to this. For example, the data processing unit 125 may perform processing using the calculated value stored in the storage unit 110 during the second cycle immediately before the first second cycle without deleting the calculated value.

<Effect in this embodiment>
The control device 100 of the above-described embodiment affects the output of the quality sensor 45 when acquiring the output value of the output sensor (for example, the quality sensor 45) for calculating the calculated value stored in the storage unit 110. Get the impact parameters. Then, when the acquired influence parameter satisfies a predetermined condition indicating the variation in the output of the quality sensor 45, the control device 100 deletes the calculated value stored in the storage unit 110.
As a result, the variation in the output value is reflected by deleting the calculated value (for example, the average value) calculated from the output value acquired when the output variation of the quality sensor 45 occurs from the storage unit 110. It is possible to suppress that the calculated value is stored in the storage unit 110. As a result, a highly accurate calculated value is stored in the storage unit 110.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes can be made within the scope of the gist thereof. is there. For example, all or a part of the device can be functionally or physically distributed / integrated in any unit. Also included in the embodiments of the present invention are new embodiments resulting from any combination of the plurality of embodiments. The effect of the new embodiment produced by the combination also has the effect of the original embodiment.

20 Exhaust passage 45 Quality sensor 100 Control device 110 Storage unit 122 Output value acquisition unit 123 Storage control unit 124 Parameter acquisition unit 125 Data processing unit S Exhaust purification system

Claims (5)

An output value acquisition unit that sequentially acquires the output value of the sensor provided in the exhaust gas purification system that purifies the exhaust gas flowing through the exhaust passage every first cycle, and
A storage control unit that sequentially stores predetermined calculated values obtained from a plurality of the output values acquired during the second cycle, which is longer than the first cycle, in the storage unit.
A parameter acquisition unit that acquires an influence parameter that affects the output of the sensor during the second cycle.
When the acquired influence parameter satisfies a predetermined condition indicating variation in the output of the sensor, a data processing unit that deletes the calculated value stored in the storage unit during the first second cycle, and a data processing unit.
A data processing device. The data processing unit stores the calculated value stored in the storage unit during the first second cycle in the storage unit during the second cycle immediately before the first second cycle. Overwrite with calculated value,
The data processing device according to claim 1. The output value acquisition unit sequentially acquires the output value of the reducing agent sensor provided in the accommodating unit accommodating the reducing agent that purifies the exhaust gas in each of the first cycles.
The data processing apparatus according to claim 1 or 2. The parameter acquisition unit acquires the temperature of the reducing agent as the influence parameter, and obtains the temperature of the reducing agent.
When the temperature change of the acquired reducing agent is larger than a predetermined degree, the data processing unit deletes the calculated value stored in the storage unit during the first second cycle.
The data processing device according to claim 3. The sensor is a heat conduction type sensor.
When the data processing unit detects that the key of the vehicle equipped with the exhaust gas purification system is turned on, the data processing unit deletes the calculated value stored in the storage unit during the first second cycle.
The data processing device according to any one of claims 1 to 3.

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