I did fuzzy damping rule base that emulates an optimal control approach with great results. See reference. Cohen, K., Weller, T., and Ben-Asher, J., “Control of Linear Second-Order Systems by a Fuzzy Logic Based Algorithm”, Journal of Guidance, Control, and Dynamics, Vol. 24, No. 3, June 2001, pp. 494-501
Article Control of Linear Second-Order Systems by Fuzzy Logic-Based Algorithm