+++ title = "Investigation on active vibration isolation of a stewart platform with piezoelectric actuators" author = ["Thomas Dehaeze"] draft = false +++ Tags : [Stewart Platforms]({{< relref "stewart_platforms" >}}), [Vibration Isolation]({{< relref "vibration_isolation" >}}), [Flexible Joints]({{< relref "flexible_joints" >}}) Reference : (Wang {\it et al.}, 2016) Author(s) : Wang, C., Xie, X., Chen, Y., & Zhang, Z. Year : 2016 **Model of the Stewart platform**: - Struts are treated as flexible beams - Payload and the base are treated as flexible plates - The FRF synthesis method permits to derive FRFs of the Stewart platform The model is compared with a Finite Element model and is shown to give the same results. The proposed model is thus effective. {{< figure src="/ox-hugo/wang16_stewart_platform.png" caption="Figure 1: Stewart Platform" >}} **Control**: Combines: - the FxLMS-based adaptive inverse control => suppress transmission of periodic vibrations - direct feedback of integrated forces => dampen vibration of inherent modes and thus reduce random vibrations Force Feedback (Figure [2](#org55d173d)). - the force sensor is mounted **between the base and the strut** {{< figure src="/ox-hugo/wang16_force_feedback.png" caption="Figure 2: Feedback of integrated forces in the platform" >}} Sorts of HAC-LAC control: - LAC: Decentralized integral force feedback - HAC: Inertial control using accelerometers. Use of the Jacobian to decouple the motion and then Fx-LMS based adaptive control is used **Experimental validation**: - All 6 transfer function from actuator force to force sensors are almost the same (gain offset) - Effectiveness of control methods are shown # Bibliography Wang, C., Xie, X., Chen, Y., & Zhang, Z., *Investigation on active vibration isolation of a stewart platform with piezoelectric actuators*, Journal of Sound and Vibration, *383()*, 1–19 (2016). http://dx.doi.org/10.1016/j.jsv.2016.07.021 [↩](#db95fac7cd46c14e2b4f38e8ca4158fe)