| 摘要 |
A control apparatus (30) and method for controlling a real time process (or other controllable activity) of which the operation can be defined by a set of P logical statements of the form STATE(N) + OMI(N,N+1) = STATE(N+1) where -N may have any integral value up to P, - STATE(N),OMI(N,N+1) and STATE(N+1) are all logical variables, and -OMI(N) is the conjunctive OPERATING MODE INCREMENT that is necessary to the progress of the system from STATE(N) to STATE(N+1) and in which SET only one such STATE variable at a time can be recognised as having the value TRUE; in which apparatus and method the following steps are performed: (i) evaluating in turn each successive STATE in at least a group of said STATES in the SET on the basis of feedback data relating to current values of various relevant parameters of the process and the current TRUE STATE, by a) determining the logical value of the preceding STATE or STATES on which said STATE is dependent, b) determining the logical value of the or each OPERATING MODE INCREMENT on which said STATE is dependent, and c) evaluating the logical statement defining said STATE, using the logical values just determined for the or each preceding STATE and the associated OPERATING MODE INCREMENT to determinethe logical value of said STATE; and (ii) initiating any relevant and necessary control action on finding a STATE having the logical value TRUE. Preferably, the identity of the STATE currently having the TRUE value is stored (location 60), and step (i) (a) aboce is performed by omparing with that stored identity the identity of the or each said preceding STATE. The control of a coal-fired furnace (10) by such method and apparatus (30) is described. |
