Active control of a flexible hub-beam system using optimal tracking control method

Active control and experiment study of a flexible hub-beam system

“…To be able to apply a linear controller, the nonlinear dynamic model must be linearized first to obtain a linearized model, and then the controller may be designed then by using linear control theory. Subsequently, the controller designed is applied to the original nonlinear dynamic model to verify its validity [11,12,17]. Below we linearize the FOAC model and use the optimal tracking control theory to design a controller.…”

“…Below we linearize the FOAC model and use the optimal tracking control theory to design a controller. In classical linearization for the flexible hub-beam system, small angular velocity of rotational motion is often assumed and the related terms and their higher order terms are neglected [11,12,17]. Increment of rotary inertia of the beam caused by its elastic deformation is also small resulting in the omission of term related to q in Eq.…”

“…Increment of rotary inertia of the beam caused by its elastic deformation is also small resulting in the omission of term related to q in Eq. (2) [11,12,17]. So the linearized model of hub-beam system is written as [11,12,17] …”

“…To achieve this goal, various control methods in automatic control field are introduced to the control of hub-beam systems. For example, Yigit [10] studied control design of a two-link rigid-flexible manipulator using the PD control strategy; Cai and Lim [11,12] investigated control design of a flexible hubbeam system using the optimal tracking control method and a time-delay controller was proposed in Ref. [12]; Li and Kang [13] presented a trajectory tracking study of multi-link flexible manipulator using the variable structure control method; Choi and Shin [14] adopted robust control strategy to study position/force control of a flexible-joint robot; Moallem et al [15,16] and Teng [17] presented experimental studies using piezoelectric (PZT) actuator as an secondary controller for a flexible manipulator.…”

“…Furthermore, few effect was ever done on experimental study of control design using the FOAC model. Since the ZOAC model fails to describe the dynamics of the system when the system is in high rotation speed, the reality of control design using the ZOAC model is suspectable even if numerical result is convergent [9,11,18]. Cai et al [9] recently investigated the dynamics and control of a hub-beam system using these two models and the research results showed that the ZOAC model may result in incorrect solution even when the system is in low speed rotation.…”