Suppressing Residual Vibrations in Comb-drive Electrostatic Actuators: A Command Shaping Technique Adapted to Nomadic Applications

The conventional unity magnitude zero vibration (UM-ZV) command shaping technique is an effective means for eliminating vibration in linear mechanical systems with on-off actuators. This paper discusses how the UM-ZV command shaping technique is affected by a common nonlinearity: nonsymmetrical accelerating and braking dynamics. Two approaches for creating new types of UM-ZV shaped commands are presented: a closed-form analytic solution and a numerical optimization approach. Both methods reduce residual vibration of the nonlinear system more effectively than the conventional UM-ZV shaped commands. Simulations and experiments on a bridge crane confirm the effectiveness of the new commands.

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Anti-Sway Control Schemes of a Boom Crane Using Command Shaping Techniques

Jurnal Teknologi ◽

10.11113/jt.v67.2842 ◽

2014 ◽

Vol 67 (5) ◽

Author(s):

M. H. I. Ishak ◽

Z. Mohamed ◽

R. Mamat

Keyword(s):

Dynamic Characteristics ◽

Comparative Assessment ◽

Input Shaping ◽

Command Shaping ◽

Control Techniques ◽

Shaping Technique ◽

Control Schemes ◽

Frequency Domains ◽

And Performance ◽

Boom Crane

This paper presents investigations into the applications and performance of command shaping techniques for control of payload sway of a boom crane based on filtering and the input shaping technique. The mathematical dynamic model describing the motion of the boom crane is developed using the Lagrange-Euler's equation. The dynamic characteristics of the system are studied and analysed using the Matlab Simulink in time and frequency domains. Command shaping techniques based on filtering and the input shaping techniques are then developed and used to control the payload sway of the boom crane. The performance of the control techniques are studied in terms of the level of sway reduction, time response and robustness. Finally, a comparative assessment of the effectiveness of the control schemes for sway control of a boom crane is presented and discussed.

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A Smooth Wave-Form Command Shaping Control

Volume 8: 22nd Reliability, Stress Analysis, and Failure Prevention Conference; 25th Conference on Mechanical Vibration and Noise ◽

10.1115/detc2013-12768 ◽

2013 ◽

Cited By ~ 3

Author(s):

Khaled A. Alhazza ◽

Ziyad N. Masoud ◽

Nehal Alotaibi

Keyword(s):

Experimental Results ◽

Harmonic Oscillators ◽

Wave Form ◽

Overhead Crane ◽

Scaled Model ◽

Smoothing Techniques ◽

Command Shaping ◽

Shaping Technique ◽

Multi Mode ◽

Smooth Acceleration

To avoid excitation of higher modes of flexible and multi-mode systems, it is important to eliminate sudden and jerky inputs. To achieve this goal, researchers tend to use different smoothing techniques to reduce the effect of the command roughness. In this work, a new smooth command-shaping technique for oscillation reduction of simple harmonic oscillators is proposed. A continuous smooth wave-form acceleration command-shaper is proposed. The shaper parameters are tuned to eliminate residual vibrations in rest-to-rest maneuvers. The performance of the proposed shaper is determined analytically, simulated numerically, and validated experimentally on a scaled model of an overhead crane. Results obtained show that the proposed smooth wave-form shaper is capable of eliminating travel and residual oscillations. Furthermore, unlike traditional step command shapers, the proposed command profiles have completely smooth acceleration, velocity, and displacement profiles. Experimental results demonstrate the ability of our proposed smooth wave-form commands to eliminate residual vibrations at the end of rest-to-rest maneuvers.

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Output-based command shaping technique for an effective payload sway control of a 3D crane with hoisting

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331216640871 ◽

2016 ◽

Vol 39 (10) ◽

pp. 1443-1453 ◽

Cited By ~ 13

Author(s):

Auwalu M Abdullahi ◽

Z Mohamed ◽

MS Zainal Abidin ◽

S Buyamin ◽

Amir A Bature

Keyword(s):

Closed Loop ◽

Reference Model ◽

Damping Ratio ◽

Time Varying ◽

Actual System ◽

Command Shaping ◽

Shaping Technique ◽

Non Linear ◽

Length Changes ◽

Travel Length

This paper presents an output-based command shaping (OCS) technique for an effective payload sway control of a 3D crane with hoisting. A crane is a challenging and time-varying system, as the cable length changes during the operation. The OCS technique is designed based on output signals of an actual system and reference model, does not require the natural frequency and damping ratio of the system, and thus can be utilized to minimize the hoisting effects on the payload sway. The shaper was designed by using the derived non-linear model of a 3D crane. To test the effectiveness of the controller, simulations using a non-linear 3D crane model and experiments on a lab-scale 3D crane were performed and compared with a zero vibration derivative (ZVD) shaper and a ZVD shaper designed using an average travel length (ATL) technique. In both the simulations and the experiments, the OCS technique was shown to be superior in reducing the payload sway with reductions of more than 56% and 33% in both of the transient and residual sways that were achieved when compared with both the ZVD and the ATL shapers, respectively. In addition, the OCS technique provided the fastest time response during the hoisting. It is envisaged that the method can be very useful in reducing the complexity of closed-loop controllers for both tracking and sway control.

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Design and Analysis of a Comb-Drive Actuator for Large Displacement

Advances in Electronic Packaging, Parts A, B, and C ◽

10.1115/ipack2005-73327 ◽

2005 ◽

Cited By ~ 1

Author(s):

C. L. Ku ◽

R. Chen ◽

Y. C. Chen

Keyword(s):

Large Displacement ◽

Electrostatic Forces ◽

Electrode Structure ◽

Comb Drive ◽

Electrostatic Actuators ◽

Drive Voltage ◽

Scanning Mirror ◽

Simulation Results ◽

Asymmetric Electrodes ◽

Novel Design

Comb-drive electrostatic actuators have been widely applied to steer a gripper, an acceleratometer, a scanning mirror, and a xy-stage because their output forces are easily controlled and capacitively sensed. To obtain large displacement with low drive voltage, a comb-drive actuator has to be designed with narrower gap and larger overlapping area between two electrodes. As a result, it will induce the instability or side sticking during operation; that is, the stationary and the moving electrodes will stick together and the actuator fails to operate. Furthermore, due to the asymmetric electrodes caused by inevitably imperfect fabrication of the actuator, the comb-drive actuator may be unstable for a large displacement, resulting from the unbalanced electrostatic forces between two electrodes. We report a novel design, which utilizes a set of extra electrode structure to compensate the unbalanced electrostatic forces. Simulation results demonstrated that the larger displacement is achieved while the size of the comb-drive actuator keeps the same. For better performance, the design of electrode structure and the number of electrodes are discussed in this report.

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Residual vibration control of underwater systems moving underwater using command shaping technique

Proceedings of the 33rd Chinese Control Conference ◽

10.1109/chicc.2014.6896966 ◽

2014 ◽

Cited By ~ 1

Author(s):

Mingxu Piao ◽

Umer Hameed Shah ◽

Jae Young Jeon ◽

Keum-Shik Hong

Keyword(s):

Vibration Control ◽

Residual Vibration ◽

Command Shaping ◽

Shaping Technique

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Demonstrating the Potential of a Novel Model to Improve Open-Loop Control of Electrostatic Comb-Drive Actuators in Electrolytes

Volume 10: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2017-71092 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ohiremen Dibua ◽

Vikram Mukundan ◽

Beth Pruitt ◽

Ali Mani ◽

Gianluca Iaccarino

Keyword(s):

Open Loop ◽

Ion Concentration ◽

Native Oxide ◽

Open Loop Control ◽

Comb Drive ◽

Electrostatic Actuators ◽

Loop Control ◽

Biological Structures ◽

Potential Applications ◽

Novel Model

Electrostatic comb-drive actuators in electrolytes have many potential applications, including characterizing biological structures. Maximizing the utility of these devices for such applications requires a model capable of accurately predicting their behavior over both micron and submicron scales of displacement. Classic circuit models of these systems assume that the native oxide is a pure dielectric, and that the ion concentration of the bulk electrolyte is constant. We propose augmented models that separately address these assumptions, and analyze their ability to predict the displacement of the electrostatic actuators in electrolytic solutions. We find that the model which removes the assumption that the native oxide is a pure dielectric most accurately predicts comb-drive actuator behavior in electrolytes.

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