Confidence-Aware Safe and Stable Control of Control-Affine Systems (2403.09067v1)
Abstract: Designing control inputs that satisfy safety requirements is crucial in safety-critical nonlinear control, and this task becomes particularly challenging when full-state measurements are unavailable. In this work, we address the problem of synthesizing safe and stable control for control-affine systems via output feedback (using an observer) while reducing the estimation error of the observer. To achieve this, we adapt control Lyapunov function (CLF) and control barrier function (CBF) techniques to the output feedback setting. Building upon the existing CLF-CBF-QP (Quadratic Program) and CBF-QP frameworks, we formulate two confidence-aware optimization problems and establish the Lipschitz continuity of the obtained solutions. To validate our approach, we conduct simulation studies on two illustrative examples. The simulation studies indicate both improvements in the observer's estimation accuracy and the fulfiLLMent of safety and control requirements.
- A. D. Ames, S. Coogan, M. Egerstedt, G. Notomista, K. Sreenath, and P. Tabuada, “Control barrier functions: Theory and applications,” in Proc. Eur. Control Conf., (Naples, Italy), June 2019, pp. 3420–3431.
- S. Wei, B. Dai, R. Khorrambakht, P. Krishnamurthy, and F. Khorrami, “Diffocclusion: Differentiable optimization based control barrier functions for occlusion-free visual servoing,” IEEE Robotics and Automation Letters, vol. 9, no. 4, pp. 3235–3242, 2024.
- B. Dai, R. Khorrambakht, P. Krishnamurthy, V. Gonçalves, A. Tzes, and F. Khorrami, “Safe navigation and obstacle avoidance using differentiable optimization based control barrier functions,” IEEE Robotics and Automation Letters, vol. 8, no. 9, pp. 5376–5383, 2023.
- B. Dai, H. Huang, P. Krishnamurthy, and F. Khorrami, “Data-efficient control barrier function refinement,” in Proc. American Control Conf., (San Diego, CA), May 2023.
- K. Reif, F. Sonnemann, and R. Unbehauen, “An EKF-based nonlinear observer with a prescribed degree of stability,” Automatica, vol. 34, no. 9, pp. 1119–1123, 1998.
- R. K. Cosner, I. D. J. Rodriguez, T. G. Molnar, W. Ubellacker, Y. Yue, A. D. Ames, and K. L. Bouman, “Self-supervised online learning for safety-critical control using stereo vision,” in Proc. International Conf. on Robotics and Automation, (Philadelphia, PA), May 2022, pp. 11 487–11 493.
- D. R. Agrawal and D. Panagou, “Safe and robust observer-controller synthesis using control barrier functions,” IEEE Control Systems Letters, vol. 7, pp. 127–132, 2022.
- Y. Wang and X. Xu, “Observer-based control barrier functions for safety critical systems,” in Proc. American Control Conf., (Atlanta, GA), June 2022, pp. 709–714.
- A. Clark, “Control barrier functions for stochastic systems,” Automatica, vol. 130, p. 109688, 2021.
- S. Wei, X. Chen, X. Zhang, and C. Qi, “Towards safe and socially compliant map-less navigation by leveraging prior demonstrations,” in International Conference on Intelligent Robotics and Applications. Springer, 2020, pp. 133–145.
- B. T. Hinson, M. K. Binder, and K. A. Morgansen, “Path planning to optimize observability in a planar uniform flow field,” in Proc. Amer. Control Conf., (Washington, DC), June 2013, pp. 1392–1399.
- P. Salaris, M. Cognetti, R. Spica, and P. R. Giordano, “Online optimal perception-aware trajectory generation,” IEEE Transactions on Robotics, vol. 35, no. 6, pp. 1307–1322, 2019.
- O. Napolitano, D. Fontanelli, L. Pallottino, and P. Salaris, “Information-aware Lyapunov-based mpc in a feedback-feedforward control strategy for autonomous robots,” IEEE Robotics and Automation Letters, vol. 7, no. 2, pp. 4765–4772, 2022.
- D. Coleman, S. D. Bopardikar, and X. Tan, “Observability-aware target tracking with range only measurement,” in Proc. American Control Conf. (New Orleans, LA), 2021, pp. 4217–4224.
- S. Bonnabel and J.-J. Slotine, “A contraction theory-based analysis of the stability of the deterministic extended Kalman filter,” IEEE Trans. on Automatic Control, vol. 60, no. 2, pp. 565–569, 2014.
- E. D. Sontag, “A ‘universal’ construction of Artstein’s theorem on nonlinear stabilization,” Systems & Control Lett., vol. 13, no. 2, pp. 117–123, 1989.
- S. Wei, P. Krishnamurthy, and F. Khorrami, “Neural Lyapunov control for nonlinear systems with unstructured uncertainties,” in Proc. American Control Conf., (San Diego, CA), May 2023.
- J. Wilkinson, “The algebraic eigenvalue problem,” in Handbook for Automatic Computation, Volume II, Linear Algebra. Springer-Verlag New York, 1971.
- M. L. Overton and R. S. Womersley, “Second derivatives for optimizing eigenvalues of symmetric matrices,” SIAM J. on Matrix Analysis and Applications, vol. 16, no. 3, pp. 697–718, 1995.
- W. W. Hager, “Lipschitz continuity for constrained processes,” SIAM J. on Control and Optimization, vol. 17, no. 3, pp. 321–338, 1979.
- M. Aicardi, G. Casalino, A. Bicchi, and A. Balestrino, “Closed loop steering of unicycle like vehicles via Lyapunov techniques,” IEEE Robotics & Automation Magazine, vol. 2, no. 1, pp. 27–35, 1995.