| In recent years, a new type compound material of road surface appeared, it has excellent performance compared with other material. At the same time, a new problem was put forward, how to measure the caking property between two materials. A new type direct shear apparatus was designed as a basic laboratory instrument to solve this problem. After investigate the products home and abroad, the paper design the control system based on the front back control panel structure. Then the paper begins to study and discuss some key technologies in this system.In the research of loading and shear system, the paper first describes two main loading solutions applied on most of the instruments. After evaluating their merits and demerits carefully, the paper give the loading solution fit for the shear apparatus. This establishes the foundation for the study of control system.In the research of back control sub-system, this paper introduces the advanced microcontroller TMS320LF2407A.then spends a lot of pages studying and analyzing some applied technologies, memory extension and configuring, basic timing system setting and power supply designing.This paper set up a set of multi-channel time-shared data acquiring system. According to the practical need for direct shear apparatus, this paper also makes a detailed discussion about the sensor, transducer sampling circuit and data converter. Finally, the DAS is realized on the control system and its system error is calculated.In the end, the paper design the software for each module of data acquiring system and analyze the logic timing of A/D, the software program flowcharts are also given, then compile most of the horizontal loading control system and lcd display software.As the research achievements showed above, the direct shear apparatus system, based on the PC and TMS320LF2407A microcontroller, with loading and shear equipment, has a bright application future and can satisfied the requirements of new type road material.
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