Fuzzy Logic-Based Pressure Control System on Triaxial Test Equipment

One of the tools used to determine soil characteristics is the Triaxial test tool. The pressure of the backpressure system on the Triaxial test equipment using the CU method must be constant due to it will affect the results of the soil sample test on the Triaxial tool. The purpose of this research is to create a back-pressure control system with liquid fluid media using Sugeno type fuzzy logic. The system was tested with a variation of 5 types of pressure, namely 1 kg/cm2, 2 kg/cm2, 3 kg/cm2, 4 kg/cm2, and 5 kg/cm2. The rise time of the control system without fuzzy is faster, respectively 1.3s, 1.1s, 1.1s, 0.8s, and 0.94 s when compared to the control system using fuzzy, but the control system without fuzzy provides an oscillating response while the fuzzy control system can achieve the stable condition without oscillation. In addition, the overshoot for each tested pressure had a difference of 13%, 15.5%, 18.34%, 16.5%, and 12.8%, respectively. The percentage of fuzzy control system overshoot is less than 3% of the steady-state, while the overshoot of the fuzzy control system is in the range of 15%-20%.