Abstract: This paper studies the application of model following sliding mode control (MFSMC) to a turbofan engine. Firstly, a method of state feedback is proposed for designing a reference model; so the reference model not only satisfies the matching conditions but also meets the performance specifications as well and moreover if the plant is decouplable, the reference model can be designed to be decoupled. Secondly, a method of pole assignment is put forward for designing switching surfaces of PI type. Finally, the MFSMC controller for a turbofan engine is designed using the above mentioned methods; dynamic simulation results show that the designed MFSMC system has no chattering phenomena and has strong robustness.

Key words: sliding mode contr ol, r eference model, switching surfaces, sta te feedback, tur bofan engine