The field testing may give the real conditions, but the uncontrolled environment may affect the results. In a soil bin, all driving conditions are controlled. Therefore a scaled soil bin was designed and established at MTC. The single wheel tester concludes the dynamic weight equal to that measured statically. Using an indoor soil bin, and measuring sensors the instantaneous wheel speed representing the theoretical speed and free wheel speed representing the actual speed were measured and recorded. Using the signals from two speed sensors, the instantaneous wheel slip is calculated. Also the dynamic sinkage due to wheel motion is measured using ultrasonic sensor. This paper presents a detailed experimental measuring of instantaneous wheel slip and dynamic sinkage on two surfaces; soft dry sand and hard surface. A theoretical control algorithm was developed and implemented. The control system using rotary valve and pressure sensor to control the tire pressure (inflation/deflation) based on the wheel slip ratio and dynamic sinkage.