A Piezoelectric Actuator-Based Direct-Drive Valve for Fast Motion Control at High Operating Temperatures

This paper experimentally investigates the control performances of a piezostack actuator direct-drive valve (PADDV) operating at high temperatures. In this study, the PADDV system is designed based on special specifications featuring a high operating temperature (150 °C) and wide control bandwidth (200 Hz). After manufacturing the PADDV with design limitations such as size and maximum input voltage to the piezostack actuator, the displacement of a spool located inside the valve system, which is directly related to the flow rate, is controlled at several different temperatures and motion frequencies. In order to undertake this, the PADDV system is installed inside a heat chamber equipped with air vessels and pneumatic–hydraulic cylinders. The piezoelectric actuator is partially insulated using an aerogel to prevent permanent damage due to high temperatures above 120 °C, which is higher than the Curie temperature. To control the valve system, a PID (proportional–integral–derivative) controller is realized in which control gains are properly tuned using fuzzy logic according to the change of temperature and frequency. It is shown from the experimental results that the proposed PADDV with thermal insulation can provide the target dynamic motion of 200 Hz at 150 °C by implementing the fuzzy-based PID controller.

The Reverse Task of Discrete Mechatronic Vibration Systems With Negative Stiffness and Capacitance Elements

By the use of different distribution methods of dynamical characteristics in the form of slowness function, mechatronic discrete systems have been synthesized. Each model consists of mechanical discrete part and a piezostack actuator connected to LxRxCx external network that has to comply with dynamical requirements in the form of poles and zeros. External network can work within different configurations. In this paper, one investigates the influence of negative parameters of stiffness in mechanical replacement models and capacitance in final mechatronic structures, after dimensionless transformations and retransformations

Frequency Dependent Vibration Attenuation of a Suspended Handle Using Piezostack Actuator

This paper investigates the effectiveness of piezostack actuator in attenuating the frequency dependent excited vibration of a suspended handle. A shaker is used to produce a base excitation to the suspended handle and a piezostack actuator is used to generate the vibration cancellation for the handle. The investigation covers vibration operating frequency from 50 to 500 Hz. This study also looked at the initial performance of piezostack actuator for the AVC system. A PID controller is design to generate the counter voltage for the piezostack actuator to attenuate the vibration of the handle. The results show that the highest vibration attenuation of the suspended handle occurred at operating frequency of 450 Hz with 90 % of vibration attenuation and the lowest at 50 Hz with 2.4 % of vibration attenuation.