Development of a combined fuzzy / PID controller for determining the required force for tractor stability in side slopes

The movement of the tractor on the side or lateral slopes causes overturning and, consequently, its damage and, in most cases, may also the driver’s death. More than 50% of accidents are related to overturning. In general, tractor overturning can be in the form of lateral and backward overturning, caused by various factors, one of which is the Sharp and uneven side slopes. In this paper, two controllers are designed as a hybrid unit, the first controller is a fuzzy controller, and the second controller is a Proportional Integral Derivative controller (PID). Simultaneously employing these two controllers, the necessary force for the stability and balance of the tractor on side slopes is determined. The performance of the integrated controller was investigated using the Simulink MATLAB environment. Combining these two controllers creates a combinatory control system that can monitor the tractor’s balance on the go on the side slope to prevent overturning phenomena. The fuzzy controller determines the required force for the tractor’s stability, and the PID controller corrects the amount of this force by considering the existing errors. The information obtained from these controllers, which is in the form of determining the force required for the tractor’s stability, is transferred to a hydraulic actuator to apply this force to the tractor body during overturning conditions on side slopes.