Design of Nonlinear Active Disturbance Rejection Controller Based on the Adaptive Particle Swarm Optimization Algorithm for the Maglev Train Traction Control System

Table 2

Main symbols and their meanings.

Symbols	Meanings
	Traction force
	Braking force
	Basic resistance
	Additional resistance
	The maglev train’s displacement
	The maglev train’s speed
	The maglev train’s acceleration
	Resultant force
	The maglev train’s total mass
	The acceleration of gravity
	Air resistance
	Electromagnetic resistance
	Ramp resistance
	Curve resistance
	The angle of the ramp
	The radius of the curve
, , and	The system gains of NLESO
	The compensation factor
and	The system gains of NLSEF
	Actual tracking speed
	Target speed
and	Learning factors
	Inertial weight values
	The individual optimum value
	The global optimum value
	The observer bandwidth