In this paper a new strategy is proposed to design a fixed-structure robust controller for a flexible beam. Robust controller designed by the conventional loop‌ shaping method is not appropriate for a beam because of its high order and complicated form. Fixed-structure loop shaping control in conjunction with particle swarm optimization (PSO)algorithm is used to overcome this drawback. The performance and robust stability conditions of the loop shaping controller are formulated as the cost function in the optimization problem. PSO is adopted to optimize the parameters and cost function. The proposed control design and loop shaping method are successfully applied on the flexible beam, and results of the two approaches are compared. Simulation results show the superiorities of the proposed controller in terms of having a lower order and simple structure; besides the beam stability and robust performance are retained as well. Also in comparison to the solutions based on genetic algorithms, the use of PSO shows better efficiency in terms of computational time. Manuscript profile