+++ title = "Investigation on active vibration isolation of a stewart platform with piezoelectric actuators" author = ["Dehaeze Thomas"] draft = false +++ Tags : [Stewart Platforms]({{< relref "stewart_platforms.md" >}}), [Vibration Isolation]({{< relref "vibration_isolation.md" >}}), [Flexible Joints]({{< relref "flexible_joints.md" >}}) Reference : (<a href="#citeproc_bib_item_1">Wang et al. 2016</a>) 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. <a id="figure--fig:wang16-stewart-platform"></a> {{< figure src="/ox-hugo/wang16_stewart_platform.png" caption="<span class=\"figure-number\">Figure 1: </span>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](#figure--fig:wang16-force-feedback)). - the force sensor is mounted **between the base and the strut** <a id="figure--fig:wang16-force-feedback"></a> {{< figure src="/ox-hugo/wang16_force_feedback.png" caption="<span class=\"figure-number\">Figure 2: </span>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 {#bibliography} <style>.csl-entry{text-indent: -1.5em; margin-left: 1.5em;}</style><div class="csl-bib-body"> <div class="csl-entry"><a id="citeproc_bib_item_1"></a>Wang, Chaoxin, Xiling Xie, Yanhao Chen, and Zhiyi Zhang. 2016. “Investigation on Active Vibration Isolation of a Stewart Platform with Piezoelectric Actuators.” <i>Journal of Sound and Vibration</i> 383 (November). Elsevier BV: 1–19. doi:<a href="https://doi.org/10.1016/j.jsv.2016.07.021">10.1016/j.jsv.2016.07.021</a>.</div> </div>