Model-Based Feedforward-Feedback Actuator Control for Real-Time Hybrid Simulation

2013 ◽  
Vol 139 (7) ◽  
pp. 1205-1214 ◽  
Author(s):  
Brian M. Phillips ◽  
Billie F. Spencer
2013 ◽  
Vol 139 (2) ◽  
pp. 219-228 ◽  
Author(s):  
Brian M. Phillips ◽  
Billie F. Spencer

Author(s):  
Cheng Chen ◽  
James M. Ricles

A Magneto-Rheological (MR) fluid damper is a semi-active device for vibration control of engineering structures subjected to dynamic loading. The characteristics of MR dampers vary under different current inputs to achieve optimized vibration control of structural systems. Experimental evaluation of MR dampers under different control laws is necessary before the device can be accepted by the practical design community. Real-time hybrid simulation provides an economical and efficient dynamic testing technique by accounting for the damper rate-dependency and the damper-structure interaction. A successful real-time hybrid simulation requires accurate actuator control to achieve reliable experiment results. A servo-hydraulic actuator usually introduces a time delay due to servo-hydraulic dynamics. The variable current inputs induced by semi-active control laws would pose additional challenges for actuator control by introducing variable delay in a real-time hybrid simulation. In this paper an adaptive compensation technique is experimentally evaluated for real-time hybrid simulation involving an MR damper under variable current inputs. Predefined band-limited white noise is used as the displacement command for the servo-hydraulic actuator and current command for the MR damper. The adaptive compensation scheme is demonstrated to achieve accurate actuator control and therefore shows great potential for real-time hybrid simulation of structural systems with semi-active energy dissipation devices.


2020 ◽  
pp. 107754632096162
Author(s):  
Zihao Zhou ◽  
Ning Li

Time delay is a critical and unavoidable problem in real-time hybrid simulation. An accurate and effective compensation method for time delay is necessary for the safety of real-time hybrid simulation and the reliability of test results. Generally, a model-based compensation method can be adopted, which is derived from the identified transfer function by assuming the latter can accurately represent the real plant. However, there must be some differences between the transfer function and the real plant. To facilitate the development of real-time hybrid simulation, we proposed a two-stage feedforward compensation method considering the error between the transfer function identified and the real plant. The compensation strategy proposed in this study was not only based on the transfer function but also introduced an error model as a second-stage compensation into a compensator to realize the synchronization of command and measurement. To verify the efficiency of the proposed method, comparisons in time domain and frequency domain with the feedforward compensator in a model-based feedforward–feedback control method were carried out. Compared with the feedforward compensator, the two-stage method achieved better tracking performance, especially in the high-frequency bandwidth. The test results verified that for a band-limited white noise of 0–30 Hz, the phase lag of the actuation system can be limited to ±5°. Finally, the two-stage method was applied to a real-time hybrid simulation of a two-story frame to illustrate its compensation effect on time delay.


2020 ◽  
Vol 219 ◽  
pp. 110868
Author(s):  
Amirali Najafi ◽  
Gaston A. Fermandois ◽  
Billie F. Spencer

2014 ◽  
Vol 13 (6) ◽  
pp. 1633-1653 ◽  
Author(s):  
Pei-Ching Chen ◽  
Chia-Ming Chang ◽  
Billie F. Spencer ◽  
Keh-Chyuan Tsai

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