ALGORITHMS AND A MICROCONTROLLER FOR STRUCTURED IMPLEMENTATION OF A TRUTH-TABLE/COMPARATOR AND OTHER GENERAL CONTROL FUNCTIONS-

PASSIVE SOLAR COMMERCIAL BUILDINGS TYPICALLY REQUIRE A HIGHER LEVEL OF SOPHISTICATION IN THE CONTROL OF MECHANICAL SYSTEMS TO ACHIEVE EFFICIENT OPERATION. THE INTEGRATED RESPONSE OF HEATING, VENTILATING, AND AIR CONDITIONING SUBSYSTEMS THAT IS CRUCIAL TO EFFICIENT THERMAL PERFORMANCE IS DIFFICULT TO IMPLEMENT WITH CONVENTIONAL SINGLE INPUT/SINGLE OUTPUT CONTROLLERS. THE APPLICATION OF ADVANCE CONTROL STRATEGIES IN SMALLER COMMERCIAL BUILDINGS, HOWEVER, IS LIMITED BY THE AVAILABILITY OF COST-EFFECTIVE HARDWARE AND SOFT- WARE. THE TRADITIONAL CONSERVATIVE APPROACH IS TO IMPLEMENT THE CONTROL LOGIC WITH RELAYS DRIVEN BY THERMOSTATS AND TIME CLOCKS. THIS APPROACH QUICKLY TENDS TO BECOME UNSATISFACTORY AS THE COMPLEXITY OF THE CONTROL STRATEGIES REQUIRES EXCESSIVE HARDWARE. ANOTHER APPROACH IS TO USE A COMPUTER SYSTEM THAT IS FULLY PROGRAMMABLE IN HIGHER LEVEL LANGUAGES TO ACHIEVE GREAT FLEXIBILITY AND INTERACTION OF CONTROL FUNCTIONS. THE SHORTCOMING OF THE FULL COMPUTER APPROACH IN SMALLER BUILDINGS IS THAT THE COST OF BOTH THE HARDWARE AND THE PROGRAMMING AND DOCUMENTATION CAN BE VERY HIGH. A POTENTIAL RESOLUTION TO THE PROBLEM OF IMPLEMENTING SOPHISTICATED CONTROL IN SMALL COMMERCIAL BUILDINGS IS DEVELOPING ALGORITHMS TO IMPLEMENT CONTROL LOGIC THAT IS CONCISELY DEFINED IN A TABULAR FORMAT. THE REPRE- SENTATION OF LOGIC IN A TRUTH TABLE WAS DEVELOPED IN THE FIELDS OF COMPUTER SCIENCE AND INFORMATION THEORY AND HAS BEEN APPLIED TO A LIMITED EXTENT FOR CONTROLS. THIS PROJECT WILL DEVELOP THE HARDWARE AND SOFTWARE NECESSARY FOR IMPLEMENTING TABLE-BASED DEFINITION OF STANDARD FUNCTIONS OF WHICH THE TRUTH TABLE IS BUT ONE EXAMPLE. THE PLANNED CONTROLLER WILL PROVIDE SOPHISTI- CATED CAPABILITIES TO UNSOPHISTICATED USERS AT MODERATE COST.