An Approach to the Development of an Integrated Real-Time Engine Test System for Agricultural Machines: Conceiving, Implementation, Set-up and First Tests

Two crucial points in the development of an experimental-test system concern specifically the instrument-management subsystem and are: (1) coordinating the acquisitions from the connected instruments and (2) making the data easily usable by the users through a rational interface. Regarding the first point, an expost synchronization of the readings previously gathered during the tests can be computationally heavy (due to: different file-formats and sampling frequencies of instruments; sometimes also non-synchronized internal clocks). Rather, a properly said instruments synchronization during the experimentation and a unique recipient for all gatherings is certainly more effective, allowing the users to have, at the end of a test session, ready-made data for any subsequent processing phase. However, its implementation requires a lot of work concerning: the set-up/creation of hardware interfaces, the writing of a software program and the implementation of a simple and reliable user interface, but it is always preferable. This approach has been followed to propose an integrated test-system for agricultural machines and all its logical steps are illustrated here as general guidelines for any future acquisition system. The management subsystem (“TRA-LOG”) of this experimental-test system is LabVIEW-based and has a graphical user-interface, developed according to modern ergonomic design concepts. TRA-LOG is able to: (1) simultaneously acquire data from a PTO-dyno, a fuel-consumption meter, an exhaust-gas analyser, many thermocouples, (2) display in real time the value of the acquisitions, (3) plot in real time the motor-performance graphs (torque, power) and other time-dependant graphs, (4) save the data in a spreadsheet-compatible format. After illustrating the development procedure and main features of this test system, we presented also its successful validation in the test of a New Holland T4020V farm tractor.