Modelling and Control System Design for Electro Magnetic Suspension System

when any vehicle runs on the road, it is subjected to bump and potholes which result in vibration that affects the passenger comfort and vehicle handling. The suspension system is an assembly of tires, springs, shock absorbers and linkages that connect a vehicle to its wheels and is used to absorb and damp out the road shocks. In designing of suspension, it is characterized by the suspension which has low spring stiffness, low damping rate which results in large suspension travel, while suspension having high damping rate is good for better handling that results in small suspension travel. These two contradictory needs the requirement of suspension with varying damping rate. This paper describes the design and simulation of a magnetic suspension system for the quarter car. Here in the designed suspension system, the damping value can be varied by changing the electric current supply in the electromagnet. Basically, this system works on Levitation technology, in which pre-defined air gap is maintained due to magnetic repulsion. Here two types of the controller are designed that is look-up table and fuzzy rules to maintain the predefined air gap. Here, when the bump comes, the air-gap fluctuation is sensed by the air sensor and this changed value of gap send to the controller and with respect to this air-gap value the current value from the look-up table or from fuzzy is decided by the controller and sends to voltage amplifier. Voltage amplifier should send that much current toward the electromagnet to vary the repulsion force which results in maintaining the predefined required air gap. Both Look-up tables and fuzzy rules are compared and validate the results.