Sliding mode control

Sliding mode control

error 모델링

오차의 기울기가 음으로 변해야 한다.

sgn 함수는 오차의 부호를 이용. 출력은 -1 0 1

의외로 간단하다.

http://en.wikipedia.org/wiki/Sliding_mode_control

In control theory , sliding mode control , or SMC , is a nonlinear control method that alters the dynamics of a nonlinear system by application of a discontinuous control signal that forces the system to "slide" along a cross-section of the system's normal behavior. The state - feedback control law is not a continuous function of time. Instead, it can switch from one continuous structure to another based on the current position in the state space. Hence, sliding mode control is a variable structure control method. The multiple control structures are designed so that trajectories always move toward an adjacent region with a different control structure, and so the ultimate trajectory will not exist entirely within one control structure. Instead, it will slide along the boundaries of the control structures. The motion of the system as it slides along these boundaries is called a sliding mode ^[ 1 ] and the geometrical locus consisting of the boundaries is called the sliding (hyper)surface . In the context of modern control theory, any variable structure system , like a system under SMC, may be viewed as a special case of a hybrid dynamical system as the system both flows through a continuous state space but also moves through different discrete control modes.

See also

• Variable structure control
• Variable structure system
• Hybrid system
• Nonlinear control
• Robust control
• Optimal control
• Bang–bang control – Sliding mode control is often implemented as a bang–bang control. In some cases, such control is necessary for optimality .
• H-bridge – A topology that combines four switches forming the four legs of an "H". Can be used to drive a motor (or other electrical device) forward or backward when only a single supply is available. Often used in actuator in sliding-mode controlled systems.
• Switching amplifier – Uses switching-mode control to drive continuous outputs
• Delta-sigma modulation – Another (feedback) method of encoding a continuous range of values in a signal that rapidly switches between two states (ie, a kind of specialized sliding-mode control)
• Pulse density modulation – A generalized form of delta-sigma modulation.
• Pulse-width modulation – Another modulation scheme that produces continuous motion through discontinuous switching.

[ edit ]Notes

1. ^ Other pulse-type modulation techniques include delta-sigma modulation .

[ edit ]References

1. ^ ^a b Zinober, ASI , ed. (1990). Deterministic control of uncertain systems . London: Peter Peregrinus Press. ISBN 978-0-86341-170-0 .
2. ^ Utkin, Vadim I. (1993). "Sliding Mode Control Design Principles and Applications to Electric Drives". IEEE Transactions on Industrial Electronics (IEEE) 40 (1): 23–36. doi : 10.1109/41.184818 .
3. ^ ^a b c d Khalil, HK (2002). Nonlinear Systems (3rd ed.). Upper Saddle River, NJ: Prentice Hall . ISBN 0-13-067389-7 .
4. ^ Filippov, AF (1988). Differential Equations with Discontinuous Right-hand Sides . Kluwer. ISBN 978-90-277-2699-5 .
5. ^ Perruquetti, W.; Barbot, JP (2002). Sliding Mode Control in Engineering . Marcel Dekker Hardcover. ISBN 0-8247-0671-4 .
6. ^ Utkin, Vadim; Guldner, Jürgen; Shi, Jingxin (1999). Sliding Mode Control in Electromechanical Systems . Philadelphia, PA: Taylor & Francis, Inc.. ISBN 0-7484-0116-4 .
7. ^ ^a b Drakunov, SV (1983). "An adaptive quasioptimal filter with discontinuous parameters". Automation and Remote Control 44 (9): 1167–1175.
8. ^ Drakunov, SV (1992). Sliding-Mode Observers Based on Equivalent Control Method . pp.

[ edit ]Further reading

• Acary, V.; Brogliato, B. (2008). Numerical Methods for Nonsmooth Dynamical Systems. Applications in Mechanics and Electronics . Heidelberg: Springer-Verlag, LNACM 35. ISBN 978-3-540-75391-9 .
• Edwards, Cristopher; Fossas Colet, Enric; Fridman, Leonid, eds. (2006). Advances in Variable Structure and Sliding Mode Control . Lecture Notes in Control and Information Sciences. vol 334 . Berlin: Springer-Verlag. ISBN978-3-540-32800-1 .
• Edwards, C.; Spurgeon, S. (1998). Sliding Mode Control: Theory and Applications . London: Taylor and Francis. ISBN 0-7484-0601-8 .
• Utkin, VI (1992). Sliding Modes in Control and Optimization . Springer-Verlag. ISBN 978-0-387-53516-6 .
• Zinober, Alan SI, ed. (1994). Variable Structure and Lyapunov Control . London: Springer-Verlag. doi : 10.1007/BFb0033675 . ISBN 978-3-540-19869-7 .