Solenoid valve abnormality detection device, medical automatic analysis device using the same, and solenoid valve abnormality detection method

Abstract

The solenoid valve abnormality detection device of the present invention can accurately estimate the open state of the solenoid valve based on the characteristic quantity of the drive current information of the solenoid valve. The solenoid valve abnormality detection device (30) detects solenoid valve abnormalities according to the drive current pattern accompanying the opening of the solenoid valve (10) detected by the current sensor (31), and includes: a feature quantity extraction unit (32) that obtains the feature quantity of the drive current pattern accompanying the opening of the solenoid valve during a predetermined detection period; a feature quantity correction unit (33) that estimates the solenoid valve temperature of the solenoid valve based on the saturation current value of the solenoid valve, and corrects the value of the feature quantity obtained by the feature quantity extraction unit to the value at the reference temperature based on the estimated solenoid valve temperature; and an open state estimation unit (34) that estimates the open state of the solenoid valve using the estimation model for estimating the open state of the solenoid valve based on the feature quantity of the drive current pattern accompanying the opening of the solenoid valve and the value of the feature quantity corrected by the feature quantity correction unit.

Description

Technical Field

[0001] The present invention relates to a solenoid valve abnormality detection device, a medical automatic analysis device using the same, and a solenoid valve abnormality detection method. The solenoid valve abnormality detection device is used to monitor the state of a solenoid valve that switches a flow path in a medical automatic analysis device or the like. Background Art

[0002] In recent years, with the rapid progress of medical technology, various medical automatic analysis devices for automatically measuring the concentration of specific components in body fluids have been introduced in clinical examination rooms such as hospitals and inspection centers. Among them, medical automatic analysis devices that can grasp internal organ diseases through the components in blood and urine have become essential devices in medical facilities regardless of their scale. The analysis unit of the medical automatic analysis device performs data processing in the order of sample dispensing, reagent dispensing, stirring, light measurement, cleaning of the reaction unit, concentration conversion, etc. In these series of operations, a large number of solenoid valves that stop or allow fluid to flow through the flow path by turning on / off the drive current are used, and high reliability of the switching operation and high-precision control of the fluid are required.

[0003] Solenoid valves are widely used in devices that require fluid control. Patent Document 1 discloses a method of estimating the switching state of a solenoid valve by using the drive current of the solenoid valve without newly adding sensors such as a position sensor or a vibration sensor. In addition, Patent Document 2 discloses a method of estimating the pressure in a flow path based on the drive current information of a solenoid valve.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2011-141019

[0007] Patent Document 2: Japanese Patent Laid-Open No. 2014-92068 Summary of the Invention

[0008] Technical Problem to be Solved by the Invention

[0009] Currently, medical automatic analysis devices do not have sensors and means for detecting abnormalities in the switching of solenoid valves. When a solenoid valve malfunctions, it may waste the specimens of patients until the device failure is determined from the analysis results.

[0010] Since many solenoid valves are used in a medical automatic analysis device, it is impossible to provide sensors for detecting abnormalities in these solenoid valves one by one, and it is desired to detect abnormalities based on the drive current information of the solenoid valves as in the prior art documents. On the other hand, in the conventional methods, solenoid valves with large flow rates and relatively large drive currents were considered, so the disclosed methods cannot be directly applied. For example, in the prior art documents, the states of fully open or closed valves were presumed, but the drive current waveforms of the solenoid valves used in medical automatic analysis devices are small, and various influencing factors are superimposed on the drive current waveforms, making the characteristics of the drive current waveforms not obvious. Therefore, it is difficult to presume the state of the solenoid valve from the drive current of the solenoid valve.

[0011] Technical solution for solving the technical problem

[0012] As a solenoid valve abnormality detection device according to an embodiment of the present invention, based on the drive current pattern of the solenoid valve detected by a current sensor during the opening of the solenoid valve, the abnormality of the solenoid valve is detected. The solenoid valve abnormality detection device includes: a feature quantity extraction unit that obtains the feature quantity of the drive current pattern of the solenoid valve during the opening of the solenoid valve within a predetermined detection period; a feature quantity correction unit that presumes the solenoid valve temperature of the solenoid valve based on the saturation current value of the solenoid valve, and corrects the value of the feature quantity obtained by the feature quantity extraction unit to a value at a reference temperature based on the presumed solenoid valve temperature; and an opening state presumption unit that presumes the opening state of the solenoid valve using a presumption model for presuming the opening state of the solenoid valve based on the feature quantity of the drive current pattern of the solenoid valve during the opening of the solenoid valve and the value of the feature quantity corrected by the feature quantity correction unit.

[0013] Advantages of the invention

[0014] The opening state of the solenoid valve can be accurately presumed with high precision using the feature quantity based on the drive current information of the solenoid valve.

[0015] The technical problems, structures, and effects other than those described above are further clarified by the following description of the embodiments. Description of the drawings

[0016] Figure 1 It is a block diagram of a solenoid valve control system.

[0017] Figure 2 It is a diagram showing a simplified structure of a non-diaphragm solenoid valve.

[0018] Figure 3 It is a diagram showing the change in the solenoid valve drive current when the solenoid valve is opened.

[0019] Figure 4It is a graph showing the change in the solenoid valve drive current when the solenoid valve is opened at each solenoid valve temperature T.

[0020] Figure 5 It is a graph showing the relationship between the solenoid valve temperature and the saturation current value.

[0021] Figure 6 It is a graph showing the change in the solenoid valve drive current when the solenoid valve is opened at each foreign object thickness F.

[0022] Figure 7 It shows Figure 6 the first-order differential (gradient) of the current.

[0023] Figure 8 It is a graph explaining the method for estimating the foreign object thickness.

[0024] Figure 9A It is an abnormal determination flowchart.

[0025] Figure 9B It is a graph showing an example of the relationship between the solenoid valve temperature and a characteristic quantity (explanatory variable).

[0026] Figure 10 It is a graph showing the change in the solenoid valve drive current when the solenoid valve is opened at each pressure P in the flow path.

[0027] Figure 11 It is a graph showing the relationship between the pressure in the flow path and the solenoid valve drive current at time C3 elapsed.

[0028] Figure 12A It is an abnormal determination flowchart.

[0029] Figure 12B It is a graph showing an example of the relationship between the pressure in the flow path and a characteristic quantity (explanatory variable).

[0030] Figure 13 It is a block diagram of a solenoid valve control system.

[0031] Figure 14 It is a block diagram of a solenoid valve control system.

[0032] Figure 15 It shows Figure 14 the solenoid valve abnormality detection device of the solenoid valve control system.

[0033] Figure 16 It is a schematic diagram of a medical automatic analyzer.

[0034] Figure 17 It is a graph showing another installation example of the solenoid valve control system. Detailed implementation

[0035] The embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the structural elements (including element steps, etc.) are not essential unless otherwise explicitly stated or clearly considered essential in principle. In addition, in the drawings corresponding to the respective embodiments, the same reference numerals are given to the same structures, and repeated explanations are omitted.

[0036] Figure 1 It is a block diagram of the solenoid valve control system 101. In the solenoid valve control system 101, as the main structure, it includes a plurality of solenoid valves 10 mounted on a medical automatic analyzer, a solenoid valve driving device 20, a solenoid valve abnormality detection device 30, and a current sensor 31. In addition, in the solenoid valve driving device 20, as the main structure, it includes a DC power supply 21, a plurality of relays 23 provided corresponding to the plurality of solenoid valves 10, a relay circuit 22 for opening and closing the relays 23, and a solenoid valve opening / closing control unit 24.

[0037] In response to the opening and closing of the relay 23, the current from the DC power supply 21 is supplied to or cut off from the solenoid valve 10. The relay 23 connected to the solenoid valve 10 is controlled by the solenoid valve opening / closing control unit 24 through the relay circuit 22, and the solenoid valve 10 is driven by the current from the DC power supply 21. The solenoid valve opening / closing control unit 24 includes hardware such as a CPU, a DSP, a RAM, and a ROM as a general computer, and stores a control program executed by the CPU, a microprogram executed by the DSP, and various data, etc. in the ROM.

[0038] (Description of the operation of the solenoid valve)

[0039] Diaphragm-type and non-diaphragm-type solenoid valves are installed in the medical automatic analyzer. In the diaphragm-type solenoid valve, there is a diaphragm (diaphragm) that is divided into a valve part for switching the flow path and a driving part for operating it, and it is suitable for the sampling part of the analyzer, medical instruments, or the treatment of acids, chemical agents, etc. that corrode metals. The non-diaphragm-type solenoid valve is a solenoid valve without a diaphragm inside, and is characterized in that the internal volume does not change due to switching, the pulsation in the flow path is small, and the pressure resistance is excellent. Figure 2The structure of a non-diaphragm solenoid valve is shown. When current flows through the coil 11 (voltage is applied), the pole piece 12 and the plunger (movable iron core) 13 are magnetized, and the plunger 13 is driven by the attraction force of each other. This driving method is also the same in the diaphragm solenoid valve. When the driving force is greater than the repulsive force of the spring 14, the rubber 15 provided on the plunger 13 is separated from the valve seat 16, and the fluid in the flow path flows (solenoid valve open state). The moving distance until the solenoid valve is fully opened is the stroke 17. On the other hand, when the current application on the solenoid valve coil 11 is cut off, the driving force is lost, and due to the repulsive force of the spring 14, the plunger 13 and the rubber 15 return to the valve seat 16, the flow path is closed, and the fluid in the flow path no longer flows (solenoid valve closed state).

[0040] Figure 3 The change of the solenoid valve drive current accompanying the opening of the solenoid valve is shown in FIG. The drive current supplied from the power supply to the solenoid valve rises after the current starts to be supplied, and the valve starts to open, that is, the rubber set on the plunger blocking the valve seat leaves the valve seat, and the drive current decreases at the same time. Then, when the plunger hits the pole piece and is adsorbed to the pole piece, the drive current of the solenoid valve rises again after passing the inflection point, and finally stabilizes at the specified current value (saturation state). Saturation current I s It is the value obtained by dividing the DC voltage E of the DC power supply 21 by the coil resistance R. In the figure, the plunger movement start period D a The period from when the drive current starts to be supplied to when the plunger starts to move is called the plunger movement period D. b The suction period D is the period from when the plunger starts to move to when it stops after moving the specified stroke. The suction period D is the period from when the plunger starts to move to when it stops after moving the specified stroke. a During the plunger movement D b sum.

[0041] As shown in the figure, for example, in the event of a foreign body being caught in the solenoid valve, the driving current variation pattern (dashed line pattern) when the solenoid valve is opening (rising) is different from the driving current variation pattern (solid line pattern) when the solenoid valve is opening normally. In addition, the saturation current (dashed line pattern) when the solenoid valve is overheated due to a coil short circuit or the like is lower than the saturation current (straight line pattern) when it is normal. Thus, the driving current pattern of the solenoid valve changes with the state of the solenoid valve as the solenoid valve opens, and when multiple abnormalities occur, the changes in the driving current pattern caused by each abnormality appear superimposed. Taking advantage of this, in this embodiment, the state related to the solenoid valve, specifically the solenoid valve temperature, the pressure in the flow path, and the solenoid valve opening state, is inferred based on the change in the driving current pattern of the solenoid valve accompanying the opening of the solenoid valve, and the abnormality of the solenoid valve is detected.

[0042] <Structure of electromagnetic valve abnormality detection device>

[0043] In the solenoid valve abnormality detection device 30, as the main structure, it includes a feature quantity extraction unit 32, a feature quantity correction unit 33, an open state estimation unit 34, a data storage unit 35 that stores data required for the abnormality detection of the solenoid valve, and an abnormality determination unit 36. The operations and processing contents in each structure of the solenoid valve abnormality detection device 30 will be described below.

[0044] <Solenoid Valve Temperature Estimation Method>

[0045] A method for estimating the solenoid valve temperature based on the change in the solenoid valve drive current mode will be described. As is well known, the coil resistance value of the solenoid valve 10 varies with the solenoid valve temperature. Here, a specified temperature is determined as the reference temperature T0, and parameters such as the resistance value at the reference temperature T0 are set as its "reference value". When the temperature rises in the solenoid valve 10, the resistance value of the solenoid valve coil becomes larger. The relationship between the solenoid valve temperature T and the solenoid valve coil resistance value R T is expressed by (Equation 1).

[0046] R T = R0×(1 + α0(T - T0))…(Equation 1)

[0047] Here, α0 is the temperature coefficient of resistance of the solenoid valve coil copper wire at the reference temperature T0, and R0 is the solenoid valve coil resistance reference value, that is, the solenoid valve coil resistance value at the reference temperature T0.

[0048] According to (Equation 1), for example, when the temperature rises by 40°C relative to the reference temperature T0, the solenoid valve coil resistance value R T is approximately 1.15 times the solenoid valve coil resistance reference value R0. In addition, even if the coil material is aluminum wire or the like, the same calculation formula can be applied.

[0049] Figure 4 is a graph showing the change in the solenoid valve drive current at each solenoid valve temperature T (T0 < T1 < T2) as the solenoid valve opens. It can be seen from the graph that compared with the solenoid valve drive current at the reference temperature T0, the solenoid valve drive currents at the higher solenoid valve temperatures T1 and T2 decrease according to (Equation 1).

[0050] In this embodiment, the detection period (in this example, the detection period C1 - C2) is determined, and the solenoid valve drive current mode accompanying the opening of the solenoid valve is grasped as a feature quantity of the drive current within the detection period. As the feature quantity, the maximum value, minimum value, average value, standard deviation, saturation current value, inflection point value, etc. of the current or current differential within the detection period can be considered. Such a determination of the detection period is due to the following reasons. For example, in Figure 4In the example, when the driving current of the solenoid valve rises, there is almost no difference in the current amount due to the temperature of the solenoid valve. If the current values during the above period are included in the calculation of the characteristic quantity of the driving current, the characteristics may be diluted. In addition, if abnormalities occur other than the temperature of the solenoid valve, unlike the case where only the temperature of the solenoid valve changes as in Figure 4 it is difficult to determine the period for calculating the characteristic quantity of the driving current based on the solenoid valve driving current pattern itself because the effects of other abnormalities are also superimposed. Therefore, for each solenoid valve, a period during which the influence of the solenoid valve temperature is significantly manifested in the solenoid valve driving current pattern accompanying the opening of the solenoid valve is determined in advance as the detection period. In addition, in the present embodiment, "each solenoid valve" means each solenoid valve for which the solenoid valve driving current pattern accompanying the opening of the solenoid valve is regarded as the same. For example, as long as the solenoid valves are of the same model, the same detection period can be determined.

[0051] For both ends C1 and C2 of the detection period, in the solenoid valve driving current pattern during normal operation, it is only necessary to select the period in which the influence of the solenoid valve temperature is manifested. However, the detection period C1 - C2 needs to include the inflection point (the end point of the attracting period D), and it is desirable to set the starting point C1 to the timing included in the plunger movement start period D a and set the end point C2 to the timing when the driving current amount reaches the saturation current value.

[0052] In addition, the starting point of the time measurement of the detection period C1 - C2 is defined as the time point when the driving current of the solenoid valve becomes the trigger current I0. Thus, the advantage of the solenoid valve abnormality detection device 30 is that it can determine the detection period and calculate the characteristic quantity of the driving current within the detection period while only monitoring the solenoid valve driving current. Of course, it is also possible to receive the control signal of the relay circuit 22 generated by the solenoid valve opening / closing control unit 24 as a trigger.

[0053] Figure 5 is a graph showing the relationship between the solenoid valve temperature and the saturation current value of the solenoid valve driving current. The saturation current value I s = E / R T , with the DC voltage E being constant and the solenoid valve coil resistance value R T having the relationship of (Equation 1), so the saturation current value I s of the solenoid valve driving current has an inverse proportional relationship with the solenoid valve temperature T as shown in (Equation 2) (the higher the solenoid valve temperature, the smaller the saturation current value of the solenoid valve driving current).

[0054] I s = k1T + b1 ··· (Equation 2)

[0055] In (Equation 2), k1 is the proportionality coefficient and b1 is the constant.

[0056] When Figure 4 When the detection period C1-C2 is set as shown, the saturation current value of the solenoid valve drive current must be the maximum value of the solenoid valve drive current. Therefore, the solenoid valve temperature can be estimated based on the characteristic value (maximum value in this example) of the solenoid valve drive current in the detection period C1-C2 without adding a temperature sensor. In addition, in this embodiment, as described below, the target variables (solenoid valve opening state, pressure in the flow path) other than the solenoid valve temperature are estimated based on the solenoid valve drive current information. However, by correcting the characteristic value related to the target variable based on the estimated temperature, the influence of the solenoid valve temperature can be eliminated from the solenoid valve drive current information, so that the target variable can be estimated more accurately. .

[0057] <Estimation of Solenoid Valve Open State>

[0058] The following describes a method for estimating the solenoid valve opening state based on changes in the solenoid valve driving current pattern. Figure 2 In the solenoid valve shown, when a foreign object is sandwiched between the pole piece 12 and the plunger 13, if the thickness of the foreign object is large, the opening of the solenoid valve becomes smaller, resulting in an abnormal decrease in the flow rate of the fluid in the flow path. Therefore, the opening state of the solenoid valve, that is, the thickness of the sandwiched foreign object, is estimated based on the characteristic amount of the drive current during the detection period of the solenoid valve drive current pattern.

[0059] Figure 6 1 is a graph showing changes in the solenoid valve drive current accompanying the opening of the solenoid valve for each thickness F (F0<F1<F2) of the sandwiched foreign matter. The solenoid valve temperature is the same in any case. Figure 7 It is shown Figure 6 The first order differential (gradient) of the solenoid valve drive current is shown in Figure 1. The position and size of the inflection point, which is greatly affected by the opening state of the solenoid valve, are more obvious in the first order differential of the solenoid valve drive current than in the solenoid valve drive current. As the thickness of the foreign matter increases (F0<F1<F2), the drive current decreases with the movement of the plunger, so that the solenoid valve drive current reaches saturation faster.

[0060] The estimation of the opening state of the solenoid valve (foreign matter thickness) uses an estimation model pre-generated for each solenoid valve based on the characteristic quantity of the driving current during the detection period. Specifically, an estimation model is constructed by multivariate analysis and other methods based on the characteristic quantity of the driving current during the detection period for the foreign matter thickness F. Here, the estimation model is an operation formula that represents the corresponding relationship between the characteristic quantity and the foreign matter thickness. For example, the estimation model of the general linear model can be expressed as (Equation 3).

[0061] Y=m0+m1V1+m2V2+···+m n V n ···(Formula 3)

[0062] Here, Y is the thickness of the foreign object (target variable) estimated from the estimation model, and V1 to V n are characteristic quantities (explanatory variables) of the drive current during the detection period, and m0 to m n are constants. For each solenoid valve, the constants m0 to m n are different values. Additionally, as the characteristic quantities (explanatory variables), those having a correlation with the thickness of the foreign object (target variable) are used. The number of n is also arbitrary, but constructing the estimation model with as few types of explanatory variables as possible can reduce the error of the estimation model.

[0063] Figure 8 This is a diagram illustrating a method for estimating the thickness of a foreign object using the general linear model method. The horizontal axis represents the measured value of the thickness of the foreign object, and the vertical axis represents the thickness of the foreign object Y estimated from the estimation model. The true thickness of the foreign object (measured value) is distributed near the estimation line 801 when the accuracy is 100% (when there is no estimation error or deviation). The limit value M1 of the thickness of the foreign object in actual application (inversely proportional to the flow path opening degree) is determined by the liquid feeding accuracy, liquid feeding volume, etc. If there is no estimation error or deviation, the upper limit of the estimated thickness of the foreign object Y can be set to Y1 on the estimation line 801 corresponding to M1. However, since it is actually impossible to ignore the estimation error or deviation, the upper limit of the estimated thickness of the foreign object is set to Y2. That is, when the estimated thickness of the foreign object Y exceeds the upper limit Y2, the fluid volume passing through the solenoid valve is lower than the required liquid feeding accuracy, and there may be insufficient liquid feeding.

[0064] Here, the general linear model method has been described as an example of the method for constructing the estimation model. However, as long as it is a model construction method representing the relationship between the thickness of the foreign object and the characteristic quantities extracted from the drive current, model methods other than the general linear model method, such as models using statistical methods, can be used. As described above, the explanatory variables V1 to V n use the corrected values based on the estimated temperature. Thereby, the thickness of the foreign object (target variable) can be estimated with higher accuracy.

[0065] Example 1

[0066] Figure 9A This is a flowchart of the abnormality determination executed by the solenoid valve abnormality detection device 30. During the operation of the medical automatic analysis device in which the solenoid valve operates, this abnormality determination routine is executed every predetermined sampling period. Thereby, even when an abnormality occurs in the solenoid valve during the operation of the medical automatic analysis device, an alarm can be output without delay, and the influence caused by the solenoid valve abnormality can be minimized.

[0067] At Figure 9AIn this process, the solenoid valve abnormality detection routine (start) is initiated, and the solenoid valve drive current measurement is performed (step S2). Specifically, the feature quantity extraction unit 32 of the solenoid valve abnormality detection device 30 (refer to Figure 1 ) receives the input of the solenoid valve drive current value I from the current sensor 31, and starts counting the timer from the time point when the current value I changes to the trigger current I0, and obtains the solenoid valve drive current value I within the preset detection period C1 - C2.

[0068] The feature quantity extraction unit 32 performs processes such as noise removal and differential processing on the obtained solenoid valve drive current value I during the detection period C1 - C2 (step S3), and calculates feature quantities such as the maximum value, minimum value, average value, standard deviation, and inflection point value of the current and current differential within the specified detection period (step S4). Additionally, the feature quantities listed here are exemplary, and only the subsequent feature quantities used to estimate the solenoid valve temperature or the open state (foreign object thickness) of the solenoid valve need to be calculated.

[0069] Next, the feature quantity correction unit 33 estimates the solenoid valve temperature using the feature quantity related to the calculated solenoid valve temperature, specifically, the maximum value of the solenoid valve drive current value I during the detection period C1 - C2 (step S5). When the estimated temperature is higher than the set limit temperature, the abnormality determination unit 36 outputs a solenoid valve heating alarm signal to the outside (step S6). The set limit temperature is stored in the data storage unit 35. If the estimated temperature is within the allowable range, the feature quantity for foreign object thickness estimation is temperature - corrected (step S7).

[0070] In the data storage unit 35, for each solenoid valve and each feature quantity (explanatory variable) V i stores information on the change amount of the feature quantity (explanatory variable) V i depending on the solenoid valve temperature. For example, as Figure 9B shown, the change amount of the feature quantity (explanatory variable) V i depending on the solenoid valve temperature is stored as a relationship of (Equation 4).

[0071] V i = k2T + b2 ··· (Equation 4)

[0072] In (Equation 4), k2 is the proportionality coefficient and b2 is the constant.

[0073] At this time, if the estimated value of the solenoid valve temperature is set as T e , and the measured value of the feature quantity (explanatory variable) V i is set as V ie , then the feature quantity (explanatory variable) V i corrected to the corresponding value at the reference temperature T0 is calculated according to (Equation 5), that is, V ic .

[0074] V ic = V ie + k2(T e − T0)···(Equation 5)

[0075] The above is an example and does not limit the calibration method. For each solenoid valve in advance, the temperature of the solenoid valve is changed in the normal operating state, and the change in the characteristic quantity of the solenoid valve drive current within a specified detection range is obtained through actual measurement or simulation. The relationship between the solenoid valve temperature and the characteristic quantity of the solenoid valve drive current is stored in the data storage unit 35 as a relational expression or a table, and temperature calibration is performed by a method corresponding to the relational expression or the table.

[0076] Next, the open state estimation unit 34 executes the operation of (Equation 3) based on the above-mentioned estimation model, using the characteristic quantity of the solenoid valve drive current that has been temperature-calibrated obtained from the characteristic quantity extraction unit 32 and the constants of the estimation model, and calculates the foreign object thickness (step S8). The estimation model is stored in the data storage unit 35.

[0077] Next, the abnormality determination unit 36 compares the foreign object thickness estimated by the estimation model with the reference value data stored in the data storage unit 35. When it is determined that the estimated foreign object thickness Y is greater than the upper limit value Y2 of the reference value data (Yes in step S8), the abnormality determination unit 36 outputs an external foreign object clamping alarm signal indicating that a foreign object exceeding the allowable range is clamped in the solenoid valve (step S9).

[0078] When it is not determined to be abnormal (No in step S6 or step S8), the processing of this routine is ended (end).

[0079] <Effect of Embodiment 1>

[0080] As described above, using the characteristic quantity based on the drive current value of the solenoid valve to estimate the solenoid valve temperature can accurately estimate the open state of the solenoid valve. In addition, by visualizing the state related to the solenoid valve, it is possible to identify a faulty solenoid valve and simplify the solenoid valve maintenance. Even in a structure where the same type of solenoid valves are mixed, since the information required for abnormality determination is stored for each solenoid valve, the determination can be made correctly.

[0081] The solenoid valve abnormality detection device can be mounted on the board of the solenoid valve drive device 20 or configured as an external device of the solenoid valve drive device 20. In addition, for the calculation of the characteristic quantity during the detection period, the sampling frequency or the amount of calculation can be adjusted as needed. As a result, the data volume can be greatly reduced according to the target variable, and the analysis and diagnosis operations become easier. In addition, machine learning or the like can be introduced into the stored data to improve the accuracy of the foreign object thickness estimation model.

[0082] Embodiment 2

[0083] In Embodiment 2, in addition to the solenoid valve temperature, the pressure inside the flow path of the flow path equipped with the solenoid valve is calculated based on the solenoid valve drive current, and the open state of the solenoid valve is estimated using a characteristic quantity of the solenoid valve drive current value during a specified detection period corrected according to the calculated pressure inside the flow path. In the following description, parts corresponding to the above-described Embodiment 1 are denoted by the same reference numerals, and their detailed description is omitted, and the description will be centered on different contents.

[0084] Figure 10 is a diagram showing the change in the solenoid valve drive current accompanying the opening of the solenoid valve under each pressure inside the flow path (P -1 <P0<P1). The solenoid valve temperature is the same in any case. Here, attention is paid to the drive current amount at a certain elapsed time C3 from the inflection point (the end of the attraction period D) until the saturation current value is reached. Although it depends on the pressure inside the flow path and the solenoid valve drive current pattern changes greatly near the inflection point (the end of the attraction period D), during the period from the inflection point to convergence to the same saturation current value, the influence of the time point deviation at the inflection point gradually decreases, and the difference in the drive current is dominated by the difference in the pressure inside the flow path.

[0085] Figure 11 is a diagram showing the relationship between the pressure inside the flow path and Figure 10 the solenoid valve drive current at the elapsed time C3 shown. As shown in the figure, the solenoid valve drive current I at the elapsed time C3 C3 has a relationship inversely proportional to the pressure P inside the flow path as shown in (Equation 6) (the higher the pressure inside the flow path, the smaller the solenoid valve drive current at the elapsed time C3).

[0086] I C3 = k3P + b3 ··· (Equation 6)

[0087] In (Equation 6), k3 is a proportionality coefficient and b3 is a constant. In Embodiment 2, the solenoid valve drive current I at the elapsed time C3 is C3 extracted as a characteristic quantity of the solenoid valve drive current value in the detection interval C1 - C2. Then, when estimating the open state of the solenoid valve, the value of the characteristic quantity used for the estimation model is set to the value corrected to the reference pressure P0 for the pressure inside the flow path. Thereby, the influence of the pressure inside the flow path can be excluded, and the state related to the solenoid valve can be estimated with higher accuracy.

[0088] Figure 12A is an abnormal determination flowchart executed by the solenoid valve abnormality detection device 30. During the operation of the medical automatic analysis device in which the solenoid valve operates, this abnormal determination routine is executed every predetermined sampling period.

[0089] InFigure 12A In this case, the process from the start of the abnormality determination routine to the temperature correction (step S7) is the same as Figure 9A However, in the feature quantity extraction (step S4), the feature quantities required for estimating the pressure in the presumed flow path are extracted. Specifically, the solenoid valve drive current I at the elapsed time C3 C3 In the temperature correction (step S7), the solenoid valve drive current I is also corrected based on the presumed temperature C3 .

[0090] The feature quantity correction unit 33 uses the extracted feature quantities related to the pressure in the flow path. Specifically, the solenoid valve drive current I at the elapsed time C3 after temperature correction C3 is used to estimate the pressure in the flow path (step S10). When the estimated pressure in the flow path is higher or lower than the set limit pressure, the abnormality determination unit 36 outputs a flow path pressure alarm signal to the outside (step S12). The set pressure in the flow path is stored in the data storage unit 35. If the estimated pressure in the flow path is within the allowable range, the feature quantity (after temperature correction) used for estimating the foreign matter thickness is pressure-corrected to the value at the reference pressure P0 (step S11).

[0091] In the data storage unit 35, information on the change amount of the feature quantity (explanatory variable) V depending on the pressure in the flow path is stored in advance for each solenoid valve and each feature quantity (explanatory variable) V i . For example, as i shown, the change amount of the feature quantity (explanatory variable) V depending on the pressure in the flow path is stored as the relationship of (Equation 7). In addition, this correlation is obtained when the solenoid valve temperature is at the reference temperature T0. Figure 12B V i = k4P + b4 ··· (Equation 7)

[0092] In (Equation 7), k4 is the proportionality coefficient and b4 is the constant. i

[0093] At this time, if the estimated value of the pressure in the flow path is set to P

[0094] , the measured value of the feature quantity (explanatory variable) V e is set to V i , then the feature quantity (explanatory variable) V ie corrected to the corresponding value of the reference pressure P0 in the flow path is calculated according to (Equation 8), that is, V i ic .

[0095] V ic = V ie + k4(P e - P0) ··· (Equation 8)

[0096] ​​The above is an example and does not limit the correction method. The pressure in the flow path is changed in advance for each solenoid valve in a normal operating state at the reference temperature T0, and the change in the characteristic quantity of the solenoid valve drive current within the specified detection interval is obtained by actual measurement or simulation, and the relationship between the pressure in the flow path and the characteristic quantity of the solenoid valve drive current is stored in the data storage unit 35 as a relational expression or table, and the pressure correction is performed by a method corresponding to the relational expression or table.

[0097] Next, from the calculation of the foreign matter thickness (step S8) to the end of the abnormality determination routine and Figure 9A However, in the calculation of the foreign matter thickness (step S8), the characteristic amount of the electromagnetic valve driving current after temperature correction and pressure correction acquired from the characteristic amount extraction unit 32 is used.

[0098] <Effects of Example 2>

[0099] As described above, in the second embodiment, the pressure in the flow path is estimated using the characteristic amount based on the driving current value of the electromagnetic valve, and the open state of the electromagnetic valve can be estimated with higher accuracy.

[0100] Hereinafter, a modification of the solenoid valve control system described as the first embodiment or the second embodiment will be described.

[0101] exist Figure 13 In the solenoid valve control system 102 shown in , the solenoid valve abnormality detection device 30 provides an alarm signal to the solenoid valve opening and closing control unit 24. According to the alarm signal provided, the solenoid valve opening and closing control unit 24 performs a recovery action on the corresponding solenoid valve. For example, when an alarm of solenoid valve overheating is received, the solenoid valve overheating failure can be prevented by postponing the time until the next operation. In addition, when a foreign body clamping alarm is received, by repeatedly opening and closing the solenoid valve, the temporarily clamped foreign body can flow into the flow path. Thus, in order to prevent the analysis device from stopping due to a solenoid valve failure, the solenoid valve control system 102 automatically performs an action for eliminating the detected solenoid valve failure.

[0102] exist Figure 14 In the solenoid valve control system 103 shown in FIG. 1 , a current sensor 31 is provided for each solenoid valve. That is, the current sensor 31 - i detects the current value I flowing through the solenoid valve 10 - i (i=1 to N). i On the other hand, if Figure 15 As shown, the electromagnetic valve abnormality detection device 301 is configured to detect the abnormality of each electromagnetic valve based on the driving current I i Detecting abnormality, the abnormality of the electromagnetic valve i is detected by the abnormality detection method described in Embodiment 1 or Embodiment 2. With this structure, even when a plurality of electromagnetic valves are opened and closed simultaneously, the abnormality of the electromagnetic valve can be estimated from the driving current information of each electromagnetic valve.

[0103] Figure 16 The figure shows a schematic diagram of a medical automatic analysis device assembled with a solenoid valve control system. The medical automatic analysis device 110 is assembled with a solenoid valve control system, which can detect abnormalities of solenoid valves assembled in the liquid delivery unit 111. The liquid delivery unit 111 includes a flow path and solenoid valves arranged in the flow path. The solenoid valve control system shows the structure of Embodiment 1 or Embodiment 2 here, but it can be a modified example or a combination of an embodiment and a modified example.

[0104] According to an alarm signal from the solenoid valve abnormality detection device 30, an alarm or warning message is displayed on the control operation screen (panel) of the automatic analysis device 110. Based on the current information of the solenoid valves of the medical automatic analysis device, the abnormal state of the solenoid valves is estimated, so that the optimization of the replacement time of each solenoid valve and the labor-saving of maintenance can be more effectively achieved.

[0105] Use Figure 17 Another installation example of the solenoid valve control system of this embodiment is described. The industrial controller 130 cooperates with the medical automatic analysis device 120 coupled through a network to achieve the control of each device, the collection of data from various sensors, and the seamless vertical integration with the upper-level information system 150. In addition, the functions of an industrial computer and the open integration development environment of a PLC (Programmable Logic Controller) are concentrated on one unit. In addition to individually controlling the medical automatic analysis device 120, the entire clinical examination room where multiple medical automatic analysis devices 120 are used for examinations is optimized by collecting and analyzing information from each device.

[0106] In such a vertically integrated environment, the industrial controller 130 includes an information collection unit 131 and a solenoid valve abnormality detection unit 132. The medical automatic analysis devices 120 each include solenoid valves 10-1 to N. The information collection unit 131 of the industrial controller 130 collects the solenoid valve drive current value I from the solenoid valve drive devices 20 of each automatic analysis device 120. The solenoid valve abnormality detection unit 132 of the industrial controller 130 has the same structure as the solenoid valve abnormality detection device described as an embodiment or a modified example, and detects abnormalities of the solenoid valves.

[0107] Thus, for multiple medical automatic analysis devices connected to the network, since the abnormal states of the multiple solenoid valves each medical automatic analysis device has can be estimated in the industrial controller, the optimization of the replacement time of each solenoid valve of each medical analysis device and the labor-saving of maintenance can be more effectively achieved.

[0108] The present invention is not limited to the above-described embodiments and variations, and various modifications can be made. The above embodiments or variations are exemplified for the purpose of easily understanding the present invention and are not limited to having all the structures described.

[0109] In addition, a part of the structure of a certain embodiment can be replaced with the structure of another embodiment, and the structure of another embodiment can also be added to the structure of a certain embodiment. Further, a part of the structure of each embodiment can be deleted or other structures can be added / replaced.

[0110] In addition, the control lines and information lines shown in the figures are considered necessary for the purpose of explanation and are not limited to showing all the necessary control lines and information lines on the product. In fact, it can be considered that almost all structures are interconnected.

[0111] Reference Numeral Explanation

[0112] 10: Solenoid valve, 11: Coil, 12: Pole piece, 13: Plunger (movable iron core), 14: Spring, 15: Rubber, 16: Valve seat, 17: Stroke, 20: Solenoid valve drive device, 21: DC power supply, 22: Relay circuit, 23: Relay, 24: Solenoid valve switch control unit, 30: Solenoid valve abnormality detection device, 31: Current sensor, 32: Feature quantity extraction unit, 33: Feature quantity correction unit, 34: Open state estimation unit, 35: Data storage unit, 36: Abnormality determination unit, 101 - 103: Solenoid valve control system, 110, 120: Medical automatic analyzer, 111: Liquid feeding unit, 130: Industrial controller, 131: Information collection unit, 132: Solenoid valve abnormality detection unit, 150: Cloud upper system, 301: Solenoid valve abnormality detection device.

Claims

1. An abnormal detection device for a solenoid valve, which detects an abnormality of the solenoid valve according to a drive current pattern of the solenoid valve accompanying the opening of the solenoid valve detected by a current sensor. The abnormal detection device for the solenoid valve is characterized by comprising: A feature quantity extraction unit that obtains a feature quantity of the drive current pattern of the solenoid valve accompanying the opening of the solenoid valve within a preset detection period; A feature quantity correction unit that estimates the solenoid valve temperature of the solenoid valve according to the saturation current value of the solenoid valve, and corrects the value of the feature quantity obtained by the feature quantity extraction unit to a value at a reference temperature based on the estimated solenoid valve temperature; and An opening state estimation unit that uses an estimation model for estimating the opening state of the solenoid valve based on the feature quantity of the drive current pattern of the solenoid valve accompanying the opening of the solenoid valve, and the value of the feature quantity corrected by the feature quantity correction unit to estimate the opening state of the solenoid valve.

2. The abnormal detection device for a solenoid valve according to claim 1, wherein The feature quantity extraction unit extracts the current value at a specified elapsed time within the detection period as one of the feature quantities of the drive current pattern of the solenoid valve accompanying the opening of the solenoid valve, The feature quantity correction unit estimates the pressure in the flow path where the solenoid valve is disposed according to the current value at the specified detection time that has been corrected to a value at the reference temperature, and corrects the value of the feature quantity that has been corrected to a value at the reference temperature to a value at the reference pressure based on the estimated pressure in the flow path.

3. The abnormal detection device for a solenoid valve according to claim 2, wherein The specified elapsed time is set as the time from when the plunger of the solenoid valve stops moving until the drive current of the solenoid valve reaches the saturation current value.

4. The abnormal detection device for a solenoid valve according to claim 1, wherein The detection period is defined by the timing when the current value detected by the current sensor becomes a specified value.

5. The abnormal detection device for a solenoid valve according to claim 1, wherein It has a data storage unit that stores the relationship between the solenoid valve temperature for estimating the solenoid valve temperature of the solenoid valve and the saturation current value of the drive current of the solenoid valve, and the relationship between the solenoid valve temperature and the feature quantity for correcting the value of the feature quantity obtained by the feature quantity extraction unit to a value at the reference temperature.

6. The abnormal detection device for a solenoid valve according to claim 2, wherein It has a data storage unit that stores the relationship between the solenoid valve temperature for estimating the solenoid valve temperature of the solenoid valve and the saturation current value of the drive current of the solenoid valve, the relationship between the pressure inside the flow path of the flow path in which the solenoid valve is arranged and the current value at the specified elapsed time at the reference temperature for estimating the pressure inside the flow path, the relationship between the solenoid valve temperature and the characteristic quantity for correcting the value of the characteristic quantity obtained by the characteristic quantity extraction unit to the value at the reference temperature, and the relationship between the pressure inside the flow path and the characteristic quantity for correcting the value of the characteristic quantity at the reference temperature to the value at the reference pressure.

7. The solenoid valve abnormality detection device according to claim 1 or 2, characterized in that it has an abnormality determination unit that outputs an alarm signal based on the state related to the solenoid valve estimated by the characteristic quantity correction unit and the open state estimation unit.

8. A medical automatic analysis device having a liquid feeding unit that includes a flow path and the solenoid valve arranged in the flow path, the medical automatic analysis device is characterized by including: a solenoid valve drive circuit for driving the solenoid valve; and the solenoid valve abnormality detection device according to claim 7, when the solenoid valve abnormality detection device outputs the alarm signal, an alarm or warning message is displayed on the operation screen.

9. The medical automatic analysis device according to claim 8, characterized in that the solenoid valve drive circuit receives the alarm signal from the solenoid valve abnormality detection device and performs a recovery operation of the solenoid valve.

10. The medical automatic analysis device according to claim 9, characterized in that the recovery operation is different depending on the state related to the solenoid valve that outputs the alarm signal.

11. The medical automatic analysis device according to claim 8, characterized in that the liquid feeding unit includes a plurality of the solenoid valves, the solenoid valve drive circuit includes: a DC power supply; a plurality of relays that are provided corresponding to the plurality of solenoid valves and control the supply of the drive current from the DC power supply to the solenoid valve; and a relay circuit that opens and closes the plurality of relays.

12. The medical automatic analysis device according to claim 11, characterized in that the current sensor detects the current value flowing between the DC power supply and the plurality of relays.

13. The medical automatic analysis device according to claim 11, characterized in that the current sensor detects the current value flowing between any one of the plurality of relays and the solenoid valve connected to the relay.

14. A solenoid valve abnormality detection method for detecting an abnormality of a solenoid valve in a medical automatic analysis device, the medical automatic analysis device having a liquid feeding unit that includes a flow path and the solenoid valve arranged in the flow path, the solenoid valve abnormality detection method is characterized in that a characteristic quantity of the drive current pattern accompanying the opening of the solenoid valve of the solenoid valve is obtained during a predetermined detection period. Estimate the solenoid valve temperature of the solenoid valve based on the saturation current value of the solenoid valve, and correct the value of the characteristic quantity to the value at the reference temperature based on the estimated solenoid valve temperature of the solenoid valve. Use the estimation model of the opening state of the solenoid valve with the characteristic quantity of the drive current mode accompanying the opening of the solenoid valve of the solenoid valve, and the value of the characteristic quantity corrected to the value at the reference temperature to estimate the opening state of the solenoid valve. When it is determined to be abnormal based on the estimated solenoid valve temperature or the opening state of the solenoid valve, output an alarm signal.

15. A method for detecting an abnormality of a solenoid valve, which detects an abnormality of a solenoid valve in a medical automatic analyzer, the medical automatic analyzer having a liquid feeding unit, the liquid feeding unit including a flow path and the solenoid valve disposed in the flow path, wherein the method for detecting an abnormality of the solenoid valve is characterized in that Obtain the characteristic quantity of the drive current mode accompanying the opening of the solenoid valve of the solenoid valve within a predetermined detection period. Extract the current value at a specified elapsed time within the detection period as one of the characteristic quantities of the drive current mode accompanying the opening of the solenoid valve of the solenoid valve. Estimate the solenoid valve temperature of the solenoid valve based on the saturation current value of the solenoid valve, and correct the value of the characteristic quantity to the value at the reference temperature based on the estimated solenoid valve temperature of the solenoid valve. Estimate the in-flow path pressure of the flow path in which the solenoid valve is disposed based on the current value at the specified elapsed time corrected to the value at the reference temperature, and correct the value of the characteristic quantity corrected to the value at the reference temperature to the value at the reference pressure based on the estimated in-flow path pressure. Use the estimation model of the opening state of the solenoid valve with the characteristic quantity of the drive current mode accompanying the opening of the solenoid valve of the solenoid valve, and the value of the characteristic quantity corrected to the values at the reference temperature and the reference pressure to estimate the opening state of the solenoid valve. When it is determined to be abnormal based on the estimated solenoid valve temperature, the in-flow path pressure or the opening state of the solenoid valve, output an alarm signal.

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