The New Triaxial Testing System

As a typical application of mechtronic technology in soil testing, triaxial instrument is the important laboratorial apparatus in the region of civil construction.In order to develop a set of advanced measure & control system equipped in triaxial instrument, this paper makes a overall analysis of function requirement for the modern triaxial instrument and then puts forward a system solution based on the front & back control panel structure.Starting from this solution, the paper begins to study and discuss the three key technologies in this system.In the research of axial loading system, this paper first describes two main loading solutions applied on all of the triaxial instruments.After evaluating their merits and demerits carefully, the loading frame is adopted.In the following pages, three technologies, step motor, motion transformation and speed reduction, are discussed in detail.In the research of back measure & control sub-system, In order to provide a strong support for measure & control system, this paper introduces the advanced microcontroller TMS320LF2407A.and spends a lot of pages studying four applied technologies, memory extension and configuring, I/O space extension, basic timing system setting and power supply designing.All the achievements of the study create a convenient road to embedded real-time operation system.In the research of data acquiring system (DAS), this paper analyses the structure of DAS and set up a set of multi-channel time-shared DAS.According to the practical need for measuring and controlling, this paper also makes a detailed discussion about the sensor, transducer sampling circuit and data converter.Finally, the DAS is realized on the measure & control system with the application of SPI interface of TMS320LF2407A and its system error is calculated.As the research achievements showed above, the measuring & controlling system, based on the PC and TMS320LF2407A microcontroller, of triaxial instrument has a bright application future and can fulfilled the need of modern triaxial testing.