The algorithms provided in the AIFAC Toolbox are based on the methods of Prof. Gang Tao of the University of Virginia and his collaborators, including Barron Associates.  Importantly, the Simulink Toolbox implementations are compatible with MathWorks real-time rapid prototyping tools, such as Real-Time Workshop.  This compatibility allows users to generate code and efficiently produce prototype and production systems that include adaptive inverse algorithms for the accommodation of uncertain nonlinear actuator dynamics. 

Adaptive Control via the Adaptive Inverse Technique

As shown below, the key features of the adaptive inverse approach are the adaptive compensator for the unknown actuator nonlinearity and the feedback adaptation for updating the compensator parameters. The essence of this adaptive approach is that, upon an adaptation transient, the compensator cancels the effects of the unknown nonlinear actuator characteristic so that a significant improvement of accuracy and performance is achieved. In other words, the adaptation of the controller is able to remove the unknown component nonlinearity so that a desired behavior of the system is realized. Note that the adaptive inverse compensator is integrated with the existing nominal guidance and control system for the plant. The nominal control system can be designed using any adaptive or non-adaptive feedback technique without considering the actuator nonlinearity.  Importantly, adaptive inverse control laws are computationally efficient and readily implementable in low-cost computing hardware. 

Recent Applications and Customers

Barron Associates, with its research partners at the University of Wyoming and the University of Virginia, has recently conducted extensive research in the areas of adaptive inverse control of synthetic jet actuators for active flow control (funded by the U.S. Air Force Office of Scientific Research and NASA Dryden Flight Research Center) and for adaptive control of flight control surfaces with actuator free-play (funded U.S Air Force Research Lab at Wright-Patterson Air Force Base).  Please contact Barron Associates for information on obtaining the AIFAC Toolbox. 

Publications 

Deb, D., G. Tao, J. Burkholder, and D. Smith, “Adaptive compensation control of synthetic jet actuator arrays for airfoil virtual shaping,” AIAA Journal of Aircraft, Vol. 44, No. 2, March-April 2007.

Deb, D., G. Tao, and J. Burkholder, “Adaptive synthetic jet actuator compensation for a nonlinear aircraft model at low angles of attack," IEEE Transactions on Control Systems Technology, Vol. 16, No. 5, September 2008.

Deb, D., G. Tao, J. Burkholder, and D. Smith, “An adaptive inverse control scheme for a synthetic jet actuator model,” Proc. of the 2005 ACC, June 2005.

Deb, D., G. Tao, J. Burkholder, and D. Smith, “An adaptive inverse control scheme for synthetic jet actuator arrays,” AIAA Infotech@Aerospace, Paper No. AIAA-2005-7170, Sept. 2005.

Deb, D., G. Tao, J. Burkholder, and D. Smith, “Adaptive compensation of nonlinearities in synthetic jet actuators for nonlinear aircraft dynamics,” Proc. of the 2006 ACC, June 2006.

Deb, D., G. Tao, J. Burkholder, and D. Smith, “Adaptive compensation of nonlinearities in synthetic jet actuators on nonlinear tailless aircraft,” Proc. of the AIAA Guidance, Navigation, and Control Conf., August 2006.

Deb, D., G. Tao, J. Burkholder, and D. Smith, “Adaptive approximation-based compensation of synthetic jet actuator nonlinearities for aircraft control,” Proc. of the 2007 AIAA Guidance, Navigation, and Control Conf., August 2007.

Shea, P. R. and Smith, D. R., “Aerodynamic control of a wing at low angles of attack using a synthetic jet and a gurney flap”, AIAA Paper 2008-0601, 46th AIAA Aerospace Sciences Meeting, Reno, NV, 2008.

Contact Info

Jason Burkholder:  burkholder@barron-associates.com