| Title |
Disturbance Observer Design for a Non-minimum Phase System That Is Stabilizable via PID Control |
| Authors |
손영익(Son, Young-Ik) ; 김성종(Kim, Sung-Jong) ; 정구종(Jeong, Goo-Jong) ; 심형보(Shim, Hyung-Bo) |
| Keywords |
Disturbance observer ; Non-minimum phase system ; Parallel connection ; LMI ; PID control |
| Abstract |
Since most disturbance observer (DOB) approaches have been limited to minimum-phase systems (or systems having no zero dynamics), we propose a new DOB structure that can be applied to non-minimum phase systems. The new structure features an additional system, which is called as V-filter, whose role is to yield a minimum phase system when connected with the plant in parallel. In order to design the V-filter systematically we first consider a class of linear systems that can be stabilized via PID controller. By inverting the controller's transfer function, we can simply construct the filter. A convenient way of designing V-filter is presented by using an iterative linear matrix inequality (LMI) algorithm. With an illustrative example the simulation result shows that substantial improvement in the performance has been achieved compared with the control system without the DOB. |