An application of morphometry to artificial systems: the evolutionary study of farm tractors

Morphometry is a method for describing and analysing statistically the shape variations within and among samples of organisms as a result of growth, experimental treatments or evolution. Morphometric methods are needed whenever there is the necessity to describe and compare shapes of organisms or of particular structures of living beings as a macroscopic result of genetic effects (i.e., as an internal response) induced by a set of external stimuli (e.g., environmental variations, geographic migrations of populations). An artificial system (movable or not) is the result of the realization of an idea aimed at solving a problem or a need that, at a certain point, has emerged in human daily-life. Hence, the very concept of a system and the proposition of possible variations or improvements concerns the idea of evolutionary adaptation. The driver of this process is, once again, external (fulfilment of a need and/or a constraint); differently from biological systems, the response arrives also from the outside of the system (designers), because, at present, no technical system is capable of self-evolving (except some particular types of computer programs). Therefore, the same morphometric methods usually adopted for living beings can also be used to study the evolution of a given artificial system over a long period, by quantifying the same technical characteristics on a set of specimens/models from different years. Regarding the agricultural machinery and tractors in particular, the need to replace animal and human labourforce and, therefore, to increase the total working-capacity, led initially to the concept of the first agricultural machines. Subsequently, over the years, a number of opportunities (new technologies, new materials) and constraints (legislative, environmental) acted on the designers as stimuli to change and improve their projects. Focussing the attention on tractors, these stimuli had as a consequence the evolution of some technical characteristics, which can be investigated, for example, by extracting homologous technical data from tractors' official documents (e.g., the test reports for OECD - Organization for Economic Co-operation and Development), as done in the study presented here. The final purpose of this investigation is tracing a series of temporal trends regarding some technical features of interest, eventually highlighting the effects of the new laws on them and investigating the achievement or not of stable values. With the present document the Authors wants to illustrate the approach, showing also, as example, a possible application of it to one technical parameter concerning the relative positioning of the centre of gravity.