Sliding Mode-Based Robust Control for Piezoelectric Actuators with Inverse Dynamics Estimation

This paper presents an improved control approach to be used for piezoelectric actuators. The proposed approach is based on sliding mode control with estimation perturbation (SMCPE) techniques. Also, a proportional-integral-derivative (PID)-type sliding surface is proposed for position tracking. The proposed approach has been studied and implemented in a commercial actuator. A model for the system is introduced, which includes the Bouc-Wen (BW) model to represent the hysteresis, and it is identified by means of the System Identification Toolbox in Matlab/Simulink. Experimental data show that the proposed controller has a better performance when compared to a proportional-integral (PI) controller or a conventional SMCPE in motion tracking. Furthermore, a sub-micrometer accuracy tracking can be obtained while compensating for the hysteresis effect.This research was partially funded by the Basque Government through the project ETORTEK KK-2017/00033, and by the UPV/EHU through the projects PPGA18/04 and UFI 11/07

Building Wireless Control Applications with XBee and LabVIEW

This study analyzed the application of the XBee technology for control applications embedded in big machinery. In particular, it presented the control layout, topology, design of frames, and error control mechanisms that are required for implementing wireless control networked applications. This study was devoted to presenting experimental use cases of wireless control systems that help the scientific community to design and implement new control systems. Experimental tests were carried out over a Single Input Single Output (SISO) control application to evaluate its use in close loop applications. The results of these tests have been discussed in detail. In order to clarify the use of XBee in control applications, a high precision positioning application has been presented. It involved a piezoelectric actuator that was remotely controlled by means of a Proportional Integral (PI) controller, which was implemented in LabVIEW over a NI myRIO platform. Both the sensor and the actuators were connected with the NI myRIO by means of the XBee anthenae. The results showed that even though XBee technologies present some drawbacks, such as a lower performance when compared to wired connections and the influence of interferences, they have the potential to be used in some scenarios for non-critical control applications.Y This research was partially funded by the Basque Government, through the project ETORTEK KK-2017/00033 and ELKARTEK KK-2019/00051, by the UPV/EHU, through the projects PPGA18/04 and UFI 11/07, and by the DFA/AFA through the project CONAVAUTIN