Papers on optimization techniques
In Gordon’s executive routine the priority of a task is calculated as a simple, usually linear, function of the time elapsed since the task was last called, with the initial priority of each task preassigned.
Abstract
In Gordon’s executive routine the priority of a task is calculated as a simple, usually linear, function of the time elapsed since the task was last called, with the initial priority of each task preassigned. Gordon mentioned some of the troubles which can occur within such a set of priorities. For example, a relatively nonessential task, such as data-logging, can accumulate such a high priority after a while that it can squelch the response to an emergency. Gordon solved this problem by putting an upper limit on the priority of nonessential tasks. However, it is then possible for some tasks never to be performed. Another problem is that some tasks might be performed too often. For example, control actions performed too often upon a pro,cess containing a long delay could lead to unstable control. This can be prevented by imposing a minimum allowable repetition period. Conversely, control actions can be so infrequent that process variables can go out of bounds. So, a rather sophisticated scheme is required. Gordon, therefore, sounded off against manufacturers who provide as many