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An improved force feedback control algorithm for active tendons.

Guo T, Liu Z, Cai L - Sensors (Basel) (2012)

Bottom Line: An active tendon, consisting of a displacement actuator and a co-located force sensor, has been adopted by many studies to suppress the vibration of large space flexible structures.The effectiveness of the algorithm is demonstrated on a structure similar to JPL-MPI.The results show that large damping can be achieved for the vibration control of large space structures.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering & Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China. gtn@bjut.com

ABSTRACT
An active tendon, consisting of a displacement actuator and a co-located force sensor, has been adopted by many studies to suppress the vibration of large space flexible structures. The damping, provided by the force feedback control algorithm in these studies, is small and can increase, especially for tendons with low axial stiffness. This study introduces an improved force feedback algorithm, which is based on the idea of velocity feedback. The algorithm provides a large damping ratio for space flexible structures and does not require a structure model. The effectiveness of the algorithm is demonstrated on a structure similar to JPL-MPI. The results show that large damping can be achieved for the vibration control of large space structures.

No MeSH data available.


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Guyed truss structure.
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f1-sensors-12-11360: Guyed truss structure.

Mentions: Most control schemes are based on an accurate model of the structure. However, when the model of the structure is not precisely defined or some active tendons fail, the performance of those control schemes deteriorates and can even cause instability of the control system. As a result, some studies have adopted decentralized schemes, which consist of independent controllers to activate specific tendons with only local feedback information. The decentralized schemes are useful for high dimensional large space structures, and can also be adapted to address the failure of some active tendons. Magana et al. [12] introduced a robust decentralized active control scheme based on the Lyapunov stability approach. Cao et al. [13] proposed a set of decentralized controllers that minimize the performance index of each subsystem to control the vibration of cable-stayed bridges subjected to vertical seismic excitation, Luo et al. [14] adopted a sliding mode decentralized controller to reduce structure vibrations by considering uncertainties in the parameters of stay cable geometry and unknown environmental excitation. Xu and Wu [15] proposed a decentralized non-parametric identification and control strategy with artificial neural networks for large-scale structures by using a neural network control scheme to reduce structure vibrations. Overall, these control schemes are complex and difficult to realize in practice. Preumont and colleagues [16–18] proposed an active tendon and integral force feedback algorithm to attenuate structure vibrations. The active tendon consists of a displacement actuator (piezoelectric actuator) and a co-located force sensor on the cable end. The preloaded active tendon is installed on the structure, as shown in Figure 1. By measuring the tension change T and controlling the active displacement, the vibration can be suppressed. The integral force feedback control algorithm is:(1)u=−gTswhere g is the integral feedback coefficient, u is the active displacement, and is the integral operator. Guo et al. [19] added a proportionality factor to the feedback law of Equation (1) and presented a proportional-integral (PI) algorithm to improve control effectiveness. The two control algorithms do not depend on the space structure model, and they are stable for the controlled structure. The control algorithm is simple, and the effectiveness of the algorithm is high. However, the achievable maximal damping ratio can be increased, especially for tendons with low axial stiffness.


An improved force feedback control algorithm for active tendons.

Guo T, Liu Z, Cai L - Sensors (Basel) (2012)

Guyed truss structure.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472888&req=5

f1-sensors-12-11360: Guyed truss structure.
Mentions: Most control schemes are based on an accurate model of the structure. However, when the model of the structure is not precisely defined or some active tendons fail, the performance of those control schemes deteriorates and can even cause instability of the control system. As a result, some studies have adopted decentralized schemes, which consist of independent controllers to activate specific tendons with only local feedback information. The decentralized schemes are useful for high dimensional large space structures, and can also be adapted to address the failure of some active tendons. Magana et al. [12] introduced a robust decentralized active control scheme based on the Lyapunov stability approach. Cao et al. [13] proposed a set of decentralized controllers that minimize the performance index of each subsystem to control the vibration of cable-stayed bridges subjected to vertical seismic excitation, Luo et al. [14] adopted a sliding mode decentralized controller to reduce structure vibrations by considering uncertainties in the parameters of stay cable geometry and unknown environmental excitation. Xu and Wu [15] proposed a decentralized non-parametric identification and control strategy with artificial neural networks for large-scale structures by using a neural network control scheme to reduce structure vibrations. Overall, these control schemes are complex and difficult to realize in practice. Preumont and colleagues [16–18] proposed an active tendon and integral force feedback algorithm to attenuate structure vibrations. The active tendon consists of a displacement actuator (piezoelectric actuator) and a co-located force sensor on the cable end. The preloaded active tendon is installed on the structure, as shown in Figure 1. By measuring the tension change T and controlling the active displacement, the vibration can be suppressed. The integral force feedback control algorithm is:(1)u=−gTswhere g is the integral feedback coefficient, u is the active displacement, and is the integral operator. Guo et al. [19] added a proportionality factor to the feedback law of Equation (1) and presented a proportional-integral (PI) algorithm to improve control effectiveness. The two control algorithms do not depend on the space structure model, and they are stable for the controlled structure. The control algorithm is simple, and the effectiveness of the algorithm is high. However, the achievable maximal damping ratio can be increased, especially for tendons with low axial stiffness.

Bottom Line: An active tendon, consisting of a displacement actuator and a co-located force sensor, has been adopted by many studies to suppress the vibration of large space flexible structures.The effectiveness of the algorithm is demonstrated on a structure similar to JPL-MPI.The results show that large damping can be achieved for the vibration control of large space structures.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering & Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China. gtn@bjut.com

ABSTRACT
An active tendon, consisting of a displacement actuator and a co-located force sensor, has been adopted by many studies to suppress the vibration of large space flexible structures. The damping, provided by the force feedback control algorithm in these studies, is small and can increase, especially for tendons with low axial stiffness. This study introduces an improved force feedback algorithm, which is based on the idea of velocity feedback. The algorithm provides a large damping ratio for space flexible structures and does not require a structure model. The effectiveness of the algorithm is demonstrated on a structure similar to JPL-MPI. The results show that large damping can be achieved for the vibration control of large space structures.

No MeSH data available.


Related in: MedlinePlus