PDF《Based Framework LPS》

6 which consists of the model in the LPS framework, which we describe below. 2.1 LPS Framework for Modeling Cutter Suction Dredging The LPS model of dredging involves basic dredging data, dynamic dredging state data, dredging processes, and dredging operation monitoring and fault detection. The LPS language consists of: a) A (deductive) Database, DB b) Process definitions, Levents c) Reactive Rules, R d) A Domain Theory, D A detailed description of the language can be found in [7]. Here we summarize the language to the extent that is sufficient to describe a schema that can be used to engi- neer the dredging application. The database DB allows representation of static (non-changing) and dynamic (changing) data, as well as definitions of concepts. The static and dynamic parts of the database incorporate basic and dynamic dredging state data, respectively. Basic dredging data involves type of the dredging area, type of soil and optimal ranges of parameters of CSD. For example, the following specify the optimal ranges of some parameters for the cutter head, given in Table 1: \* range(part, param, soil type, low, high, unit) */ range(cutterHead, load, sand, 11.07, 13.81, MPa). range(cutterHead, rotation_speed, sand, 25, 30, r/m). range(cutterHead, swing_speed, sand, 9.62, 10.61, m/min). Dynamic dredging state data involves the changing operational state of the dredging, for example indicated by the monitors and sensors, indicating production, cutter head load, slurry density and speed in various locations along the networks of pipes. For example: even(cutter_load). indicates that currently cutter load is even. This may change during the operation if the teeth of the cutter head are damaged, for example. In the simulation the monitor readings are also considered part of the dynamic part of the knowledge base. For ex- ample: \* reading(part, param, value) */ reading(cutterHead, load, 12). stating that the current monitor reading for cutter head load is 12, and reading(dischargePipe, production, 1.4). stating that the current monitor reading for production at the discharge pipe is 1.4. The concept definitions in DB allow representation of concepts and parameters that depend on other concepts and parameters. For example the following states that the value of an operational parameter, Param, for equipment part, Part, is low if for the given soil type, S, the read value of the parameter lies below the lower bound of the parameter's optimal range. low(Part, Param) :- soil_type(S), range(Part, Param, S, L, H, Unit), reading(Part, Param, V), V