Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering


Throughout the history of agriculture man has sought improved methods of tilling soil. Technological developments in recent years have enabled man to apply large amounts of mechanical energy to soil tillage. But, as the energy limitations of the world begin to be realized, the development of more efficient means of soil tillage will become increasingly important. In tillage machine design, as in other engineering design fields, the designer has three basic methods of predicting the performance of a system. Murphy (12) states these methods as (i) application of existing laws and formulas, (ii) observations on the actual systems, and (iii) use of model systems, or similitude. The first method has not been successfully applied to tillage, while the second method has been and still is widely used in evaluating the performance of tillage machines. However, it is expensive, time consuming, and restrictive. Within the last 20 years, the third method which uses modeling and similitude theory has been applied to tillage studies. Some of the advantage of studying modeled tillage systems are: I, better control of the environment, ii. Better control over soil conditions, iii. Better application of instrumentation technology, iv. Less expense with model construction, and v. easy alteration of models. This research was conducted to further the application of modeling and similitude theory to soil-machine systems. The goal was to investigate and expand the application of an analog prediction technique which was proposed by Schafer (20).

Library of Congress Subject Headings


Analog computers



Number of Pages



South Dakota State University