Design of a high speed DDA

The objective of the company-funded task which supported this work was to develop techniques for high-speed solutions to differential equations, particularly those which are common in aerospace problems. For example, the solution requirements for reentry guidance are very time-limited and must be processed at the highest priority level. To solve this type of problem, depending on the accuracy required, the number of iterations can get unreasonably large and require an inordinate amount of computer "power." Therefore, the solution time requirements led us to investigate means other than the general purpose computer to solve these time-critical differential equations. The nature of the problem and the aerospace requirements of long term drift stability and accuracy led us to choose the digital differential analyzer (DDA) as one of the candidates for investigation. This paper, then, is concerned with the new techniques in DDA design which were developed in order to meet the solution time objectives.