Dither control for Dahl model based hysteresis compensation

Prakash

Mathematical Problems in Engineering

et al. 2015

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Piezoelectric-stack actuated platforms are very popular in the parlance of nanopositioning with myriad applications like micro/nanofactory, atomic force microscopy, scanning probe microscopy, wafer design, biological cell manipulation, and so forth. Motivated by the necessity to improve trajectory tracking in such applications, this paper addresses the problem of rate dependent hysteretic nonlinearity in piezoelectric actuators (PEA). The classical second order Dahl model for hysteresis encapsulation is introduced first, followed by the identification of parameters through particle swarm optimization. A novel inversion based feedforward mechanism in combination with a feedback compensator is proposed to achieve high-precision tracking wherein the paradoxical concept of noise as a performance enhancer is introduced in the realm of PZAs. Having observed that dither induced stochastic resonance in the presence of periodic forcing reduces tracking error, dither capability is further explored in conjunction with a novel output harmonics based adaptive control scheme. The proposed adaptive controller is then augmented with an internal model control based approach to impart robustness against parametric variations and external disturbances. The proposed control law has been employed to track multifrequency signals with consistent compensation of rate dependent hysteresis of the PEA. The results indicate a greatly improved positioning accuracy along with considerable robustness achieved with the proposed integrated approach even for dual axis tracking applications.

Section: Mathematical Problems In Engineeringmentioning

confidence: 99%

On Synergistic Integration of Adaptive Dithering Based Internal Model Control for Hysteresis Compensation in Piezoactuated Nanopositioner

Prakash

Mathematical Problems in Engineering

et al. 2015

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“…Dither inputs have been used in control systems and signal processing applications to alleviate the effects of nonlinearity, hysteresis, quantization, gear backlash, etc. Studies have shown that dithering holds amazing capabilities when it comes to linearizing the effects of hysteretic nonlinearity in piezoelectric actuators [18][19][20][21]. Injection of a suitable dose of noise stimulates the manifestation of the popular phenomenon of SR.…”

Section: B Unadaptive Dithered Nonlinear Control Paradigmmentioning

confidence: 99%

“…In fact, noise has been used as a powerful tool in the fields of control systems and signal processing to realize better levels of performance. Recent studies have investigated noise induced performance boost in the domain of piezoelectric actuators [18][19][20][21]. The noise which is used to corrupt the otherwise pure system for augmenting the system capabilities is generally called dither.…”

Section: Introductionmentioning

confidence: 99%

Adaptive linearization of hysteresis for enhanced positional accuracy of robotic arm

Prakash

2014 Annual International Conference on Emerging Research Areas: Magnetics, Machines and Drives (AICERA/iCMMD)

et al. 2014

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Precision control of multi-axis piezo actuated micro / nanopositioning stages suffers not only from the inherent nonlinearities but also from parametric variations and uncertainties. In order to effectively implement any real-time control theory to mitigate the effects of nonlinearity, an adaptive mechanism to update the control system is a prerequisite. This paper investigates the effects of hysteretic nonlinearity in a second order Dahl model based piezoelectric manipulator. The plant performance is known to improve with injection of a suitable dose of noise called "dither". The concept of dither based control is interwoven with the conventional PID controller to introduce a novel adaptive dither control strategy. A double axis piezo stage is considered for controller design and validation. The controller performance is ascertained using three specific tests-a) Tracking Error Test, b) Multi-frequency, multi-amplitude tracking test and c) Two-axis Circular Contour Tracking Test.Results show an enhanced positioning accuracy of the manipulator in the presence of proposed control scheme than without it. The proposed control transpires as an effective control to improve tracking accuracy and resist external disturbances.

“…[7][8][9][10][11][12][13]. A few researches have used inversion technique through feed-forward topology in an open loop scenario, to suppress hysteresis [14][15]. A combined feed-forward and feedback topology has been seen to reduce hysteresis primarily although simultaneously taking into consideration, vibration and creep, which are the other non-linearity exhibited by piezo-ceramics [16].…”

Section: Introductionmentioning

confidence: 99%

Dither based precise position control of piezo actuated micro-nano manipulator

IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society

Mukherjee

et al. 2013

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This paper addresses the problem of hysteresis and presents a new control scheme for hysteresis compensation of piezo-electrically actuated micro-nano manipulators. The technology employs an Inverse Dahl model based feed-forward mechanism in combination with a feedback control algorithm along with simultaneous voltage and displacement dither strategy. The actuator performance is seen to improve as a function of injected noise level into the plant -a phenomenon known as dithering. The notion of stochastic resonance for nano positioning is studied to determine the optimal dither level for efficient plant performance. The efficacy of the proposed control scheme has been confirmed through rigorous simulations in terms of two specific tests -a) tracking error test and b) hysteresis curve area test. Results show an enhanced positioning precision of the manipulator with the proposed dither control than without it. Owing to its algorithmic simplicity, the proposed control genre can be extended to the parlance of other nano-scale applications.