Patent Description:
In recent years, with rapid progress in medical technologies, various types of automatic medical analysis apparatuses that automatically measure a concentration of a specific component in a body fluid are introduced into clinical laboratories in such as hospitals and examination centers, and among these apparatuses, an automatic medical analysis apparatus capable of grasping a visceral disease by components in blood or urine is an essential apparatus for a medical facility regardless of scale. An analysis unit of the automatic medical analysis apparatus sequentially performs sample dispensing, reagent dispensing, stirring, photometry, cleaning of a reaction cell, and data processing such as concentration conversion. In this series of operations, many solenoid valves that cause a fluid in a flow path to stop or flow by turning on or turning off a driving current are used, and high reliability of opening/closing operations and high accuracy control of the fluid passing through the flow path are required.

A solenoid valve is widely used in a device that is required to control a fluid. PTL <NUM> discloses a method for estimating an opening and closed state of a solenoid valve using a solenoid valve driving current without newly adding a sensor such as a position sensor or a vibration sensor. PTL <NUM> discloses a method for estimating a flow path internal pressure based on driving current information of a solenoid valve. Document <CIT> discloses a system that uses solenoid coil voltage and current sensing along with knowledge of coil resistance at a known temperature to derive coil temperature. The derived temperature is compared to a threshold temperature and if the derived temperature is above the threshold, the system removes power from the solenoid to protect the solenoid from overheating. When the derived temperature is below the threshold, the system uses the temperature in a solenoid control algorithm to perform solenoid drive temperature compensation. The solenoid control algorithm uses the solenoid current feedback together with the derived solenoid coil temperature to improve power efficiency.

In a current automatic medical analysis apparatus, a sensor or unit that detects an opening/closing abnormality of a solenoid valve is not mounted, and when an abnormality occurs in the solenoid valve, a sample of a patient may be wasted until an apparatus failure is found based on an analysis result.

Since many solenoid valves are used in the automatic medical analysis apparatus, a sensor that detects the abnormality cannot be provided for each of the solenoid valves, and it is desirable to detect the abnormality based on driving current information of the solenoid valves as in the prior art documents. On the other hand, in methods in the related art, a solenoid valve having a large flow rate and a considerably large solenoid valve driving current is considered as a target, and the disclosed methods cannot be applied directly. For example, although a complete valve opening or valve closed state is estimated in the prior art documents, a driving current waveform of the solenoid valve used in the automatic medical analysis apparatus is small, and various factors affecting the driving current waveform are superimposed, so that it is difficult to understand characteristics of the driving current waveform. Therefore, it is difficult to estimate the state of the solenoid valve based on the solenoid valve driving current.

A solenoid valve abnormality detection device according to an aspect of the invention as defined in claim <NUM> is a solenoid valve abnormality detection device for detecting an abnormality of a solenoid. valve based on a driving current pattern which is associated with solenoid valve opening of the solenoid valve and which is detected by a current sensor. The solenoid valve abnormality detection device includes: a feature data extraction unit configured to obtain feature data of the driving current pattern associated with the solenoid valve opening of the solenoid valve in a predetermined detection period;' a feature data correction unit configured to estimate a solenoid valve temperature of the solenoid valve based on a saturation current value of the solenoid valve, and correct a value of the feature data obtained by the feature data extraction unit to a value at a reference temperature that is based on the estimated solenoid valve temperature; and an opening state estimation unit configured to estimate an opening state of the solenoid valve using an estimation model configured to estimate the opening state of the solenoid valve based on the feature data of the driving current pattern associated with the solenoid valve opening of the solenoid valve and the value of the feature data corrected by the feature data correction unit.

It is possible to accurately estimate an opening state of a solenoid valve using feature data based on driving current information of the solenoid valve.

Problems, configurations, and effects other than those described above will be apparent from the following description of embodiments.

Embodiments of the invention will be described in detail with reference to the drawings. In the following embodiments, elements (also including element steps and the like) are not essential unless otherwise specified or considered to be obviously essential in principle. In the drawings corresponding to the embodiments, the same components are denoted by the same reference numerals, and redundant descriptions will be omitted.

<FIG> is a block diagram of a solenoid valve control system <NUM>. The solenoid valve control system <NUM> includes, as a main configuration, a plurality of solenoid valves <NUM>, a solenoid valve driving device <NUM>, a solenoid valve abnormality detection device <NUM>, and a current sensor <NUM>, which are mounted on an automatic medical analysis apparatus. Further, the solenoid valve driving device <NUM> includes, as a main configuration, a DC power supply <NUM>, a plurality of relays <NUM> provided corresponding to the plurality of solenoid valves <NUM>, a relay circuit <NUM> that opens and closes the relays <NUM>, and a solenoid valve opening/closing control unit <NUM>.

In response to opening and closing of the relays <NUM>, a current from the DC power supply <NUM> is supplied to or cut off from the solenoid valves <NUM>. The relays <NUM> respectively connected to the solenoid valves <NUM> are controlled by the solenoid valve opening/closing control unit <NUM> through the relay circuit <NUM>, and the solenoid valves <NUM> are driven by the current from the DC power supply <NUM>. The solenoid valve opening/closing control unit <NUM> includes hardware as a general computer such as a CPU, a DSP, a RAM, and a ROM. The ROM stores a control program executed by the CPU, a microprogram executed by the DSP, various types of data, and the like.

A diaphragm type solenoid valve and a non-diaphragm type solenoid valve are mounted on the automatic medical analysis apparatus. The diaphragm type solenoid valve includes a film (diaphragm) divided into a valve portion that opens and closes a flow path and a driving portion that moves the valve portion, and is suitable for a sampling portion of an analysis apparatus, medical equipment, or handling of acids, chemical agents, and the like that corrode metals. The non-diaphragm type solenoid valve is a solenoid valve including no diaphragm therein, and is characterized in that there is no change in an internal volume due to opening and closing, pulsation in the flow path is small, and pressure resistance is excellent. <FIG> shows a structure of the non-diaphragm type solenoid valve. When a current flows through a coil <NUM> (voltage application), a pole piece <NUM> and a plunger (movable iron core) <NUM> are magnetized, and the plunger <NUM> is driven by a mutual attracting force. This driving method is the same for the diaphragm type solenoid valve. When a driving force is larger than a repulsive force of a spring <NUM>, a rubber <NUM> set in the plunger <NUM> is separated from a valve seat <NUM>, and a fluid in the flow path flows (solenoid valve opening state). A movement distance until the solenoid valve is fully open is a stroke <NUM>. On the other hand, by cutting off the current applied to the coil <NUM> of the solenoid valve, the driving force is lost, and the plunger <NUM> and the rubber <NUM> are returned to the valve seat <NUM> due to the repulsive force of the spring <NUM> to close the flow path, so that the fluid in the flow path does not flow (solenoid valve closed state).

<FIG> shows a change in a solenoid valve driving current associated with solenoid valve opening. The driving current supplied from the power supply to the solenoid valve increases after the current supply starts, and decreases at the same time as the valve starts to be opened, that is, the rubber set in the plunger that blocks the valve seat is separated from the valve seat. Then, when the plunger hits and is absorbed by the pole piece, the solenoid valve driving current rises again through an inflection point, and is finally stable at a predetermined current value (saturated state). A saturation current Is is a value obtained by dividing a DC voltage E of the DC power supply <NUM> by coil resistance R. In the drawing, a plunger movement start period Da is a period from when the supply of the driving current starts to when a movement of the plunger starts, a plunger movement period Dp is a period from when the movement of the plunger starts, to when the plunger is moved by a specified stroke and stops, and an attracting period D is a sum of the plunger movement start period Da and the plunger movement period Db.

As shown in the drawing, for example, when a foreign matter is sandwiched in the solenoid valve, a driving current variation pattern (broken line pattern) during a solenoid valve opening operation (rise) is different from a driving current variation pattern (solid line pattern) during a solenoid valve opening operation in a normal state. In addition, a saturation current amount (broken line pattern) when the solenoid valve is overheated due to a coil short circuit or the like is smaller than a saturation current amount (straight line pattern) in the normal state. Thus, a solenoid valve driving current pattern associated with the solenoid valve opening varies in accordance with the state of the solenoid valve, and when a plurality of abnormalities occur, the variation of the driving current pattern due to each abnormality appears in a superimposed manner. By utilizing this fact, in the present embodiment, states related to the solenoid valve, specifically, a solenoid valve temperature, a flow path internal pressure, and the solenoid valve opening state are estimated based on the change in the solenoid valve driving current pattern associated with the solenoid valve opening, and the abnormality of the solenoid valve is detected.

The solenoid valve abnormality detection device <NUM> includes, as a main configuration, a feature data extraction unit <NUM>, a feature data correction unit <NUM>, an opening state estimation unit <NUM>, a data storage unit <NUM> that stores data necessary for abnormality detection of the solenoid valve, and an abnormality determination unit <NUM>. Descriptions of operations and processing contents in configurations of the solenoid valve abnormality detection device <NUM> will be described later.

A method for estimating the solenoid valve temperature based on the change in the solenoid valve driving current pattern will be described. As is generally well known, a coil resistance value of the solenoid valve <NUM> varies depending on the solenoid valve temperature. Here, a predetermined temperature is determined as a reference temperature T<NUM>, and a parameter such as a resistance value at the reference temperature T<NUM> is set as a "reference value" at the reference temperature. When the temperature of the solenoid valve <NUM> rises, the resistance value of the coil of the solenoid valve increases. A relationship between a solenoid valve temperature T and a solenoid valve coil resistance value RT can be expressed by (Equation <NUM>).

Here, α<NUM> is a resistance temperature coefficient of a solenoid valve coil copper wire at the reference temperature T<NUM>, and R<NUM> is a solenoid valve coil resistance reference value, that is, a solenoid valve coil resistance value at the reference temperature T<NUM>.

According to (Equation <NUM>), for example, when a temperature rises by <NUM> with respect to the reference temperature T<NUM>, the solenoid valve coil resistance value RT is about <NUM> times the solenoid valve coil resistance reference value R<NUM>. When the coil is made of a material such as aluminum wire, the same calculation equation can also be applied.

<FIG> is a diagram showing a change in the solenoid valve driving current associated with the solenoid valve opening at each solenoid valve temperature T (T<NUM> < T<NUM> < T<NUM>). As can be seen from the drawing, as compared with the solenoid valve driving current at the reference temperature T<NUM>, the solenoid valve driving currents at the solenoid valve temperatures T<NUM> and T<NUM> higher than the reference temperature T<NUM> decrease in accordance with (Equation <NUM>).

In the present embodiment, a detection period (in this example, a detection period from C<NUM> to C<NUM>) is determined, and the solenoid valve driving current pattern associated with the solenoid valve opening is grasped as feature data of the driving current in the detection period. As the feature data, a maximum value, a minimum value, an average value, a standard deviation, a saturation current value, an inflection point value, and the like of the current or a current differential in the detection period are considered. Reasons why the detection period is determined in this manner are as follows. For example, in the example of <FIG>, there is almost no difference in current amount caused by the solenoid valve temperature during the rise of the solenoid valve driving current. When the feature data of the driving current is calculated by including the current value in such a period, features may be diluted. In addition, unlike a case where only the solenoid valve temperature changes as shown in <FIG>, when abnormalities other than the solenoid valve temperature also occur, influences of other abnormalities are also superimposed, and thus it is difficult to specify the period for calculating the feature data of the driving current based on the solenoid valve driving current pattern itself. Therefore, for each solenoid valve, a period in which an influence of the solenoid valve temperature remarkably appears in the solenoid valve driving current pattern associated with the solenoid valve opening is determined in advance as the detection period. In the present embodiment, the expression "each solenoid valve" means each solenoid valve whose solenoid valve driving current pattern associated with the solenoid valve opening is considered to be the same. For example, in a case of solenoid valves having the same model number, the same detection period can be determined.

For C<NUM> and C<NUM> which are two ends of the detection period, a period in which the influence of the solenoid valve temperature appears in the solenoid valve driving current pattern at a time of normal operation may be selected, but, the detection period from C<NUM> to C<NUM> needs to include the inflection point (an end point of the attracting period D), and it is desirable that the start point C<NUM> is set to a timing included in the plunger movement start period Da, and the end point C<NUM> is set to a timing at which a driving current amount reaches the saturation current value.

In addition, a starting point of time measurement of the detection period from C<NUM> to C<NUM> is defined as a time point at which the solenoid valve driving current becomes a trigger current Io. Accordingly, the solenoid valve abnormality detection device <NUM> has advantages in that the detection period can be specified while monitoring only the solenoid valve driving current and that the feature data of the driving current in the detection period can be calculated. Of course, it is also possible to receive a control signal of the relay circuit <NUM> by the solenoid valve opening/closing control unit <NUM> and use the control signal as a trigger.

<FIG> is a diagram showing a relationship between the solenoid valve temperature and the saturation current value of the solenoid valve driving current. Since the saturation current value Is = E/RT, the DC voltage E is constant, and the solenoid valve coil resistance value RT has the relationship of (Equation <NUM>), the saturation current value Is of the solenoid valve driving current is inversely proportional to the solenoid valve temperature T (the higher the solenoid valve temperature is, the smaller the saturation current value of the solenoid valve driving current is) as expressed by (Equation <NUM>).

In (Equation <NUM>), k<NUM> is a proportional coefficient, and b<NUM> is a constant.

When the detection period from C<NUM> to C<NUM> is set as shown in <FIG>, the saturation current value of the solenoid valve driving current is the maximum value of the solenoid valve driving current. Therefore, it is possible to estimate the solenoid valve temperature based on the feature data (in this example, the maximum value) of the solenoid valve driving current in the detection period from C<NUM> to C<NUM> without adding a temperature sensor. Further, in the present embodiment, as will be described later, an objective variable (solenoid valve opening state and flow path internal pressure) other than the solenoid valve temperature is estimated based on driving current information of the solenoid valve, and by correcting the feature data correlated with the objective variable based on the estimated temperature, the influence of the solenoid valve temperature can be eliminated from the driving current information of the solenoid valve, and the objective variable can be estimated more accurately.

A method for estimating the solenoid valve opening state based on the change in the solenoid valve driving current pattern will be described. In the solenoid valve shown in <FIG>, when a foreign matter is sandwiched between the pole piece <NUM> and the plunger <NUM>, an opening degree of the solenoid valve reduces if a foreign matter thickness is large. As a result, an abnormality occurs in which a flow rate of the fluid in the flow path reduces. Therefore, the solenoid valve opening state, that is, the thickness of the sandwiched foreign matter is estimated based on the feature data of the driving current in the detection period of the solenoid valve driving current pattern.

<FIG> is a diagram showing a change in the solenoid valve driving current associated with the solenoid valve opening at each thickness F (F<NUM> < F<NUM> < F<NUM>) of the sandwiched foreign matter. In any case, the solenoid valve temperature is the same. <FIG> is a diagram showing a first-order differential (gradient) of each solenoid valve driving current of <FIG>. A position and a size of the inflection point in which the solenoid valve opening state is greatly affected appear more remarkably in the first-order differential of the solenoid valve driving current than in the solenoid valve driving current. As the foreign matter thickness increases (F<NUM> < F<NUM> < F<NUM>), the decrease in the driving current associated with the movement of the plunger is reduced, and the solenoid valve driving current reaches saturation earlier.

The solenoid valve opening state (foreign matter thickness) is estimated using an estimation model created in advance based on the feature data of the driving current in the detection period for each solenoid valve. Specifically, the estimation model is constructed for the foreign matter thickness F by a method such as multivariate analysis based on the feature data of the driving current in the detection period. Here, the estimation model is an arithmetic expression representing a correspondence relationship between the feature data and the foreign matter thickness. For example, the estimation model based on a generalized linear model can be expressed by (Equation <NUM>).

Here, Y is a foreign matter thickness (objective variable) estimated based on the estimation model, V<NUM> to Vn are feature data (explanatory variables) of the driving current in the detection period, and m<NUM> to mn are constants. The constants m<NUM> to mn have different values depending on the solenoid valve. The feature data (explanatory variable) uses feature data correlated with the foreign matter thickness (objective variable), and the number of n is freely selected, but errors of the estimation model can be reduced by constructing the estimation model with as few types of explanatory variables as possible.

<FIG> is a diagram showing a method for estimating the foreign matter thickness using a generalized linear model method. A horizontal axis represents measurement values of foreign matter thicknesses, and a vertical axis represents foreign matter thicknesses Y estimated based on the estimation model. True foreign matter thicknesses (measurement values) are distributed in the vicinity of an estimation line <NUM> when accuracy is <NUM>% (without estimation error or variation). A limit value M<NUM> of the foreign matter thickness (inversely proportional to an opening degree of the flow path) in an actual operation is determined by liquid feeding accuracy, a liquid feeding amount, and the like. When there is no estimation error or variation, an upper limit of the estimated foreign matter thickness Y can be set to Y<NUM> on the estimation line <NUM> corresponding to M<NUM>, but the estimation error and the variation cannot be ignored in practice, so that the upper limit of the estimated foreign matter thickness is set to Y<NUM>. That is, it is assumed that, when the estimated foreign matter thickness Y exceeds the upper limit Y<NUM>, the amount of fluid passing through the solenoid valve is smaller than required liquid feeding accuracy, and liquid feeding insufficiency may occur.

Here, the generalized linear model method is described as an example of an estimation model construction method, but a model method other than the generalized linear model method, such as a model using a statistical method, may be used as long as the model construction method indicates the relationship between the foreign matter thickness and the feature data extracted from the driving current. As described above, the explanatory variables V<NUM> to Vn used in the estimation model use values corrected based on an estimated temperature. Accordingly, it is possible to estimate the foreign matter thickness (objective variable) with higher accuracy.

<FIG> is an abnormality determination flowchart executed by the solenoid valve abnormality detection device <NUM>. An abnormality determination routine is executed at a predetermined sampling period during an operation of the automatic medical analysis apparatus in which the solenoid valve is operated. Accordingly, even when an abnormality occurs in the solenoid valve during the operation of the automatic medical analysis apparatus, an alarm is output without delay, and an influence of the abnormality in the solenoid valve can be minimized.

In <FIG>, a solenoid valve abnormality detection routine is started (START), and a solenoid valve driving current measurement is executed (step S2). Specifically, the feature data extraction unit <NUM> of the solenoid valve abnormality detection device <NUM> (see <FIG>) receives input of a solenoid valve driving current value I from the current sensor <NUM>, starts counting by a timer from a time point when the current value I is the trigger current I<NUM>, and acquires the solenoid valve driving current value I in a predetermined detection period from C<NUM> to C<NUM>.

The feature data extraction unit <NUM> performs processing such as noise removal and differentiation processing on the acquired solenoid valve driving current value I in the detection period from C<NUM> to C<NUM> (step S3), and calculates the feature data such as the maximum value, the minimum value, the average value, the standard deviation, and the inflection point value of the current and the current differential in the predetermined detection period (step S4). The feature data exemplified here are examples, and only the feature data used for subsequent estimation of the solenoid valve temperature or an estimation of the solenoid valve opening state (foreign matter thickness) may be calculated.

Next, the feature data correction unit <NUM> estimates the solenoid valve temperature using the feature data correlated with the calculated solenoid valve temperature, specifically, the maximum value of the solenoid valve driving current value I in the detection period from C<NUM> to C<NUM> (step S5), and when the estimated temperature is higher than a set limit temperature, the abnormality determination unit <NUM> outputs a solenoid valve overheated alarm signal to the outside (step S6). The set limit temperature is stored in the data storage unit <NUM>. When the estimated temperature is within an allowable range, temperature correction is performed on the feature data used for estimating the foreign matter thickness (step S7).

In the data storage unit <NUM>, information on a change amount of feature data (explanatory variable) Vi depending on the solenoid valve temperature is stored in advance for each solenoid valve and each piece of feature data (explanatory variable) Vi. For example, as shown in <FIG>, it is assumed that the change amount of the feature data (explanatory variable) Vi depending on the solenoid valve temperature is stored as a relationship expressed by (Equation <NUM>).

At this time, when it is assumed that an estimated value of the solenoid valve temperature is Te and a measured value of the feature data (explanatory variable) Vi is Vie, Vic which is the feature data (explanatory variable) Vi corrected to an equivalent value at the reference temperature T<NUM> is calculated by (Equation <NUM>).

The above is merely an example, and the correction method is not limited thereto. In advance, for each solenoid valve, in a normal operation state, the solenoid valve temperature is changed, a change in the feature data of the solenoid valve driving current in the predetermined detection section is obtained by actual measurement or simulation, a relationship between the solenoid valve temperature and the feature data of the solenoid valve driving current is stored in the data storageunit <NUM> as a relational expression or a table, and temperature correction is performed by a method corresponding to the relational expression or the table.

Next, based on the estimation model described above, the opening state estimation unit <NUM> calculates the foreign matter thickness by performing a calculation of (Equation <NUM>) using the feature data of the solenoid valve driving current which is subjected to the temperature correction and acquired from the feature data extraction unit <NUM> and the constants of the estimation model (step S8). The estimation model is stored in the data storage unit <NUM>.

Next, the abnormality determination unit <NUM> compares the foreign matter thickness estimated by the estimation model with reference value data stored in the data storage unit <NUM>. When it is determined that the estimated foreign matter thickness Y is larger than the upper limit value Y<NUM> that is the reference value data (YES in step S8), the abnormality determination unit <NUM> outputs, to the outside, a foreign matter sandwiched alarm signal indicating that a foreign matter exceeding the allowable range is sandwiched in the solenoid valve (step S9).

When it is determined that no abnormality occurs (step S6 or NO in step S8), the processing of this routine ends (END).

As described above, the solenoid valve temperature can be estimated using the feature data of the solenoid valve driving current value, and the solenoid valve opening state can be accurately estimated. In addition, by visualizing states related to the solenoid valve, it is possible to specify a failed solenoid valve and save labor in solenoid valve maintenance. Even in a configuration in which different types of solenoid valves are mixed, it is possible to perform accurate determination since information necessary for abnormality determination is stored for each solenoid valve.

The solenoid valve abnormality detection device may be mounted on a board of the solenoid valve driving device <NUM> or may be configured as an external device of the solenoid valve driving device <NUM>. In addition, in the feature data calculation in the detection period, a sampling frequency or a calculation amount may be adjusted as necessary. Accordingly, the amount of data can be greatly reduced by the objective variable, and analysis and diagnosis work also is facilitated. Further, machine learning or the like can be introduced into stored data, and accuracy of the estimation model for the foreign matter thickness can be increased.

In a second embodiment, in addition to a solenoid valve temperature, a flow path internal pressure of a flow path in which a solenoid valve is disposed is calculated based on a solenoid valve driving current, and a solenoid valve opening state is estimated using feature data of a solenoid valve driving current value corrected based on the calculated flow path internal pressure in a predetermined detection period. In the following description, portions corresponding to those of the first embodiment described above are denoted by the same reference numerals, detailed descriptions thereof are omitted, and different contents will be mainly described.

<FIG> is a diagram showing a change in the solenoid valve driving current associated with solenoid valve opening for each flow path internal pressure (P-<NUM> < P<NUM> < P<NUM>). In any case, the solenoid valve temperature is the same. Here, a driving current amount at a certain elapsed time C<NUM> before the solenoid valve driving current reaches a saturation current value from an inflection point (an end point of the attracting period D) is focused on. Although a solenoid valve driving current pattern greatly changes in the vicinity of the inflection point (the end point of the attracting period D) depending on the flow path internal pressure, an influence of a deviation at a time point of reaching the inflection point is gradually reduced during a period from the inflection point to a convergence to the same saturation current value, and a difference in the driving current is dominated by a difference in the flow path internal pressure.

<FIG> is a diagram showing a relationship between the flow path internal pressure and the solenoid valve driving current at the elapsed time C<NUM> shown in <FIG>. As shown in the drawing, the solenoid valve driving current IC3 at the elapsed time C<NUM> is inversely proportional to the flow path internal pressure P (the higher the flow path internal pressure is, the smaller the solenoid valve driving current at the elapsed time C<NUM> is) as indicated in (Equation <NUM>).

In (Equation <NUM>), k<NUM> is a proportional coefficient, and b<NUM> is a constant. In the second embodiment, the solenoid valve driving current IC3 at the elapsed time C<NUM> is extracted as the feature data of the solenoid valve driving current value in the detection section from C<NUM> to C<NUM>. Then, in estimating of the solenoid valve opening state, the feature data used in an estimation model is set to a value obtained by correcting the flow path internal pressure to a value at a reference pressure P<NUM>. Accordingly, it is possible to eliminate an influence of the flow path internal pressure and estimate states related to the solenoid valve with higher accuracy.

<FIG> is an abnormality determination flowchart executed by the solenoid valve abnormality detection device <NUM>. This abnormality determination routine is executed at a predetermined sampling period during an operation of an automatic medical analysis apparatus in which the solenoid valve is operated.

In <FIG>, temperature correction (step S7) from a start of the abnormality determination routine is the same as a flow of <FIG>. However, the feature data extraction (step S4) includes extraction of the feature data necessary for estimating the flow path internal pressure, specifically, extraction of the solenoid valve driving current IC3 at the elapsed time C<NUM>, and the temperature correction (step S7) also includes correction of the solenoid valve driving current IC3 based on an estimated temperature.

The feature data correction unit <NUM> estimates the flow path internal pressure using the feature data correlated with the extracted flow path internal pressure, specifically, the solenoid valve driving current IC3 at the elapsed time C<NUM> which is subjected to the temperature correction (step S10). When the estimated flow path internal pressure is higher or lower than a set limit pressure, the abnormality determination unit <NUM> outputs a flow path internal pressure alarm signal to the outside (step S12). A set flow path internal pressure is stored in the data storage unit <NUM>. When the estimated flow path internal pressure is within an allowable range, pressure correction is performed on the feature data - (after temperature correction) used for estimating the foreign matter thickness to obtain a value at the reference pressure P<NUM> (step S11).

In the data storage unit <NUM>, information on a change amount in the feature data (explanatory variable) Vi depending on the flow path internal pressure is stored in advance for each solenoid valve and each piece of feature data (explanatory variable) Vi. For example, as shown in <FIG>, it is assumed that the change amount of the feature data (explanatory variable) Vi depending on the flow path internal pressure is stored as a relationship of (Equation <NUM>). This correlation is obtained when the solenoid valve temperature is equal to or lower than the reference temperature T<NUM>.

At this time, when it is assumed that an estimated value of the flow path internal pressure is Pe and a measured value of the feature data (explanatory variable) Vi is Vie, Vic which is the feature data (explanatory variable) Vi corrected to an equivalent value at the reference flow path internal pressure P<NUM> is calculated by (Equation <NUM>).

The above is merely an example, and the correction method is not limited thereto. In advance, for each solenoid valve, in a normal operation state under the reference temperature T<NUM>, the flow path internal pressure is changed, a change in the feature data of the solenoid valve driving current in a predetermined detection section is obtained by actual measurement or simulation, a relationship between the flow path internal pressure and the feature data of the solenoid valve driving current is stored in the data storage unit <NUM> as a relational expression or a table, and pressure correction is performed by a method corresponding to the relational expression or the table.

Hereinafter, the processing from the calculation of the foreign matter thickness (step S8) to an end of the abnormality determination routine is the same as the flow of <FIG>. However, in the calculation of the foreign matter thickness (step S8), the feature data of the solenoid valve driving current which is subjected to the temperature correction and the pressure correction and which is acquired from the feature data extraction unit <NUM> is used.

As described above, in the second embodiment, the flow path internal pressure can be estimated using the feature data of the solenoid valve driving current value, and the solenoid valve opening state can further be accurately estimated.

Hereinafter, modifications of the solenoid valve control system shown as the first embodiment or the second embodiment will be described.

In a solenoid valve control system <NUM> shown in <FIG>, the solenoid valve abnormality detection device <NUM> supplies an alarm signal to the solenoid valve opening/closing control unit <NUM>. In response to the supplied alarm signal, the solenoid valve opening/closing control unit <NUM> executes a recovery operation for a corresponding solenoid valve. For example, when a solenoid valve overheated alarm is received, a solenoid valve overheated failure can be prevented by delay in a time to a next operation. In addition, when a foreign matter sandwiched alarm is received, the solenoid valve is repeatedly opened and closed, so that a temporarily sandwiched foreign matter can be caused to flow into a flow path. In this manner, in order to prevent an analysis apparatus from being stopped due to a failure of the solenoid valve, the solenoid valve control system <NUM> automatically executes an operation of solving a detected failure of the solenoid valve.

In a solenoid valve control system <NUM> shown in <FIG>, the current sensor <NUM> is provided for each solenoid valve. That is, a current sensor <NUM>-i detects a current value Ii flowing through a solenoid valve <NUM>-i (i = <NUM> to N). Meanwhile, as shown in <FIG>, a solenoid valve abnormality detection device <NUM> is configured to detect, for each solenoid valve, an abnormality based on a driving current Ii, and detects an abnormality of a solenoid valve i by the abnormality detection method described in the first embodiment or the second embodiment. According to this configuration, even when a plurality of solenoid valves are simultaneously opened and closed, it is possible to estimate abnormalities of the solenoid valves based on driving current information of the respective solenoid valves.

<FIG> is a schematic diagram of an automatic medical analysis apparatus incorporating the solenoid valve control system of the present embodiment. An automatic medical analysis apparatus <NUM> incorporates the solenoid valve control system capable of detecting an abnormality of a solenoid valve incorporated in a liquid feeding unit <NUM> including a flow path and the solenoid valve disposed in the flow path. Here, the solenoid valve control system is shown to have the configuration of the first embodiment or the second embodiment, and may also be a modification or a combination of the embodiments and the modifications.

In response to an alarm signal from the solenoid valve abnormality detection device <NUM>, an alarm or a warning message is displayed on a control operation screen (panel) of the automatic medical analysis apparatus <NUM>. By estimating an abnormal state of the solenoid valve based on current information on the solenoid valve of the automatic medical analysis apparatus, it is possible to optimize a replacement period of each solenoid valve and save labor in maintenance more efficiently.

Another implementation example of the solenoid valve control system of the present embodiment will be described with reference to <FIG>. An industrial controller <NUM> cooperates with automatic medical analysis apparatuses <NUM> connected by a network, and achieves control on each apparatus, collection of data from various sensors, and seamless vertical integration with a host information system <NUM>. In addition, functions of an industrial computer and an open integrated development environment of a programmable logic controller (PLC) are integrated into one. Not only the automatic medical analysis apparatuses <NUM> are controlled individually, but also an entire clinical laboratory in which an examination is performed using a plurality of automatic medical analysis apparatuses <NUM> is optimized by collecting and analyzing information from each apparatus.

In an environment in which such vertical integration is achieved, the industrial controller <NUM> includes an information collection unit <NUM> and a solenoid valve abnormality detection unit <NUM>. Each of the automatic medical analysis apparatuses <NUM> includes solenoid valves <NUM>-<NUM> to <NUM>-N. The information collection unit <NUM> of the industrial controller <NUM> collects the solenoid valve driving current value I from the solenoid valve driving device <NUM> of each automatic medical analysis apparatus <NUM>. The solenoid valve abnormality detection unit <NUM> of the industrial controller <NUM> has the same configuration as that of the solenoid valve abnormality detection device described in the embodiments or the modifications, and detects an abnormality of the solenoid valve.

In this manner, for the plurality of automatic medical analysis apparatuses connected to the network, the industrial controller can estimate an abnormal state of each of the plurality of solenoid valves provided in each automatic medical analysis apparatus. Therefore, it is possible to optimize a replacement period of each solenoid valve in each automatic medical analysis apparatus and save labor in maintenance more efficiently.

The invention is not limited to the embodiments and modifications described above, and various modifications are possible as long as they fall within the scope of the claims. The embodiments and the modifications described above are examples for easy understanding of the invention, and the invention is not necessarily limited to those including all the configurations described above.

A part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. In addition, a part of the configuration of each embodiment can be deleted, or another configuration can be added or replaced.

Claim 1:
A solenoid valve abnormality detection device for detecting an abnormality of a solenoid valve (<NUM>) based on a driving current pattern which is associated with solenoid valve opening of the solenoid valve and which is detected by a current sensor (<NUM>), the solenoid valve abnormality detection device comprising:
a feature data extraction unit (<NUM>) configured to obtain feature data of the driving current pattern associated with the solenoid valve opening of the solenoid valve in a predetermined detection period;
a feature data correction unit (<NUM>) configured to estimate a solenoid valve temperature of the solenoid valve based on a saturation current value of the solenoid valve, and correct a value of the feature data obtained by the feature data extraction unit to a value at a reference temperature that is based on the estimated solenoid valve temperature; and
an opening state estimation unit (<NUM>) configured to estimate an opening state of the solenoid valve using an estimation model configured to estimate the opening state of the solenoid valve based on the feature data of the driving current pattern associated with the solenoid valve opening of the solenoid valve and the value of the feature data corrected by the feature data correction unit.