Method and apparatus for diagnosing plant anomaly
First Claim
1. A method for diagnosing a plant anomaly corresponding to measured data supplied from the plant, the method comprising the steps of:
- sampling the measured data;
deciding from the sampled measured data whether a state of each function of the plant is normal; and
inferring an origin of the plant anomaly from a plant model in an abstract function level, the plant model being composed of model elements, by determining whether a state of each of the model elements is normal starting downward from the top of a hierarchy of the plant model corresponding to information obtained in the deciding step, the plant model having a goal and a flow structure, the goal representing a purpose to be accomplished by a lower flow structure and a condition for supporting a higher flow structure, and the flow structure being represented by flow of either of mass or energy through a flow function; and
detecting a failure propagation network having each model element which has not been determined as a normal element in the model element determining step.
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Abstract
Determined results of which measured data of a plant is normal/abnormal are mapped to a plant model in an abstract function level hierarchically represented with flow structures of mass/energy and goals to be accomplished by the respective flow structures so as to detect a failure propagation network. In the failure propagation network, a flow structure at the lowest hierarchical level of a network with a top goal of the highest priority is selected as an object to be diagnosed first. In other words, flow structures that are functionally important and close to the origin of anomaly are preferentially diagnosed. The diagnosis for flow structures detects abnormal elements through hypothesis and test. The abnormal element are evaluated with respective mass/energy balances or the like. With respect to the evaluated result, the origin of failure is inferred based on the rule of experience. When the abnormal element has a detailed flow structure, it is diagnosed. Thus, an abnormal position can be detected in more detail.
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Citations
28 Claims
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1. A method for diagnosing a plant anomaly corresponding to measured data supplied from the plant, the method comprising the steps of:
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sampling the measured data; deciding from the sampled measured data whether a state of each function of the plant is normal; and inferring an origin of the plant anomaly from a plant model in an abstract function level, the plant model being composed of model elements, by determining whether a state of each of the model elements is normal starting downward from the top of a hierarchy of the plant model corresponding to information obtained in the deciding step, the plant model having a goal and a flow structure, the goal representing a purpose to be accomplished by a lower flow structure and a condition for supporting a higher flow structure, and the flow structure being represented by flow of either of mass or energy through a flow function; and detecting a failure propagation network having each model element which has not been determined as a normal element in the model element determining step. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for diagnosing a plant anomaly corresponding to measured data supplied from the plant, the method comprising the steps of:
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sampling the measured data; deciding from the sampled measured data whether a state of each function of the plant is normal; and inferring an origin of the plant anomaly with a plant model in an abstract function level corresponding to information obtained in the measured data deciding step, the plant model having a flow structure represented by flow of mass or energy through a flow function, wherein the inferring step includes the steps of a first hypothesis step of assuming that each flow function on each path linked between flow functions determined as abnormal with measured data not through a flow function determined as normal with the measured data is abnormal in the flow structure; estimating a state amount related to each flow function assumed as abnormal in the first hypothesis step; evaluating whether each flow function determined as abnormal by the first hypothesis step is abnormal with the estimated state amount based on a deviation from a normal value, a balance of input and output of the flow function, and a restriction corresponding to a type of the flow function; and detecting an origin of failure of the flow structure based on a rule of experience corresponding to an evaluated result. - View Dependent Claims (13, 14, 15)
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16. An apparatus for diagnosing an anomaly of a plant corresponding to measured data supplied from the plant, comprising:
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means for storing a plant model hierarchically representing function of the plant in an abstract function level, the plant model having a flow structure and a goal as a model element, the flow structure being represented by flow of either of mass or energy through a flow function, and the goal representing a purpose to be accomplished by a lower flow structure and a condition for supporting a higher flow structure; measured amount deciding means for obtaining a state amount related to the plant model corresponding to the measured data and comparing the state amount with a threshold thereof so as to decide whether or not the state amount is normal; means for inferring an origin of the anomaly of the plant using the plant model corresponding to information supplied from said measured amount determining means; and a display unit for displaying an inference process and result supplied from said inferring means, wherein said inferring means includes means for determining whether a functional state of each model element is normal downward from the top in a hierarchy of the plant model based on the information supplied from the measured amount determining means; and means for detecting a failure propagation network having each model element which has not been determined as normal by said model element determining means. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. An apparatus for diagnosing an anomaly of a plant corresponding to measured data supplied from the plant, comprising:
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means for storing a plant model in an abstract function level, the plant model having a flow structure represented by flow of mass or energy through a flow function; measured amount deciding means for obtaining a state amount related to the plant model corresponding to the measured data and comparing the state amount with a threshold thereof so as to decide whether or not the state amount is normal; means for inferring an origin of the anomaly of the plant using the plant model corresponding to information supplied from said measured amount determining means; and a display unit for displaying an inference process and result supplied from said inferring means, wherein said inferring means includes; first hypothesis means for assuming that each flow function on each path linked between flow functions determined as abnormal by said measured amount determining means not through a flow function determined as normal by said measured amount determining means is abnormal in the plant model; means for estimating a state amount related to each flow function assumed as abnormal by said first hypothesis means; means for evaluating whether or not each flow function determined as abnormal by said first hypothesis means is abnormal with the estimated state amount based on a deviation from a normal value, a balance of input and output of the flow function, and a restriction corresponding to a type of the flow function; and first detecting means for detecting an origin of failure of the flow function based on a rule of experience corresponding to an evaluated result. - View Dependent Claims (26, 27, 28)
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Specification