In this paper, we present a new particle swarm optimization. We call it a fourth order particle swarm optimization. The original PSO has position and velocity vectors. However, the proposed algorithm has four terms: i.e. a position vector, a velocity vector, an acceleration vector and a jerk vector. From the proposed PSO, we obtain the fourth order difference equation and from the equation we obtain the convergence region for five parameters. By setting five parameters near the convergence region, with the proposed PSO algorithm we design PID coefficients for the automatic voltage regulators. We show that the proposed algorithm has better performance than the original PSO for the PID design of automatic voltage regulators.