An Improved Adaptive Feedforward Cancellation for Trajectory Tracking of Fast Tool Servo Based on Fractional Calculus

In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to achieve a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using proportional–integral–derivative (PID) controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking.

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A novel hybrid control strategy for trajectory tracking of fast tool servo

2010 2nd International Conference on Mechanical and Electronics Engineering ◽

10.1109/icmee.2010.5558416 ◽

2010 ◽

Author(s):

Xiaoqin Zhou ◽

Zhiwei Zhu ◽

Shaoxin Zhao ◽

Dan Luo

Keyword(s):

Trajectory Tracking ◽

Control Strategy ◽

Hybrid Control ◽

Fast Tool Servo

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Multi-Physical Design and Resonant Controller Based Trajectory Tracking of the Electromagnetically Driven Fast Tool Servo

10.20944/preprints202003.0179.v1 ◽

2020 ◽

Author(s):

Imran Hussain ◽

Wei Xia ◽

Dongpo Zhao ◽

Peng Huang ◽

Zhiwei Zhu

Keyword(s):

Natural Frequency ◽

Trajectory Tracking ◽

Voice Coil Motor ◽

Diamond Turning ◽

Analytical Models ◽

Physical Parameters ◽

Fast Tool Servo ◽

Element Analysis ◽

Loop Control ◽

Resonant Controller

In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to have a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using PID controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking.

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Adaptive Trajectory Tracking During Motorized and FES-Induced Biceps Curls via Integral Concurrent Learning

Volume 1: Adaptive/Intelligent Sys. Control; Driver Assistance/Autonomous Tech.; Control Design Methods; Nonlinear Control; Robotics; Assistive/Rehabilitation Devices; Biomedical/Neural Systems; Building Energy Systems; Connected Vehicle Systems; Control/Estimation of Energy Systems; Control Apps.; Smart Buildings/Microgrids; Education; Human-Robot Systems; Soft Mechatronics/Robotic Components/Systems; Energy/Power Systems; Energy Storage; Estimation/Identification; Vehicle Efficiency/Emissions ◽

10.1115/dscc2020-3125 ◽

2020 ◽

Author(s):

Brendon C. Allen ◽

Kimberly J. Stubbs ◽

Warren E. Dixon

Keyword(s):

Trajectory Tracking ◽

High Gain ◽

Control Input ◽

Loop Control ◽

Concurrent Learning ◽

Control Effectiveness ◽

Uncertain Dynamics ◽

Clinically Significant ◽

Opportunistic Learning ◽

Adaptive Feedforward

Abstract A common rehabilitative technique for those with neuro-muscular disorders is functional electrical stimulation (FES) induced exercise such as FES-induced biceps curls. FES has been shown to have numerous health benefits, such as increased muscle mass and retraining of the nervous system. Closed-loop control of a motorized FES system presents numerous challenges since the system has nonlinear and uncertain dynamics and switching is required between motor and FES control, which is further complicated by the muscle having an uncertain control effectiveness. An additional complication of FES systems is that high gain feedback from traditional robust controllers can be uncomfortable to the participant. In this paper, data-based, opportunistic learning is achieved by implementing an integral concurrent learning (ICL) controller during a motorized and FES-induced biceps curl exercise. The ICL controller uses adaptive feedforward terms to augment the FES controller to reduce the required control input. A Lyapunov-based analysis is performed to ensure exponential trajectory tracking and opportunistic, exponential learning of the uncertain human and machine parameters. In addition to improved tracking performance and robustness, the potential of learning the specific dynamics of a person during a rehabilitative exercise could be clinically significant. Preliminary simulation results are provided and demonstrate an average position error of 0.14 ± 1.17 deg and an average velocity error of 0.004 ± 1.18 deg/s.

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Modeling and Compensation for Hysteresis Nonlinearity of a Piezoelectrically Actuated Fast Tool Servo Based on a Novel Linear Model

ISRN Mechanical Engineering ◽

10.5402/2012/626142 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Zhiwei Zhu ◽

Xiaoqin Zhou ◽

Jieqiong Lin ◽

Qiang Liu

Keyword(s):

Fractional Calculus ◽

Linear Model ◽

Fractional Order ◽

Analytical Description ◽

Open Loop ◽

Fast Tool Servo ◽

Compensation Strategy ◽

Hysteresis Nonlinearity ◽

Series Of Experiments ◽

Compensation Approach

In order to describe and compensate for complex hysteresis nonlinearities of piezoelectrically actuated fast tool servo (FTS), a novel Linear Fractional order Differentiation Hysteresis (LFDH) model is proposed in this paper. By means of the proposed LFDH model which is established on the fractional calculus theory, an analytical description of hysteresis behaviors of the FTS is derived. Furthermore, the LFDH model-based inverse compensation strategy is proposed to suppress the hysteresis effects of the FTS. Finally, a series of experiments are conducted to verify the effectiveness of the LFDH model and the corresponding compensation approach. The results demonstrate that the proposed LFDH model is efficient for describing hysteresis behaviors and the inverse compensation strategy can significantly suppress the inherent hysteresis of the FTS in open-loop operations.

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