A Method for Selecting Velocity Filter Cut-Off Frequency for Maximizing Impedance Width Performance in Haptic Interfaces

This paper analyzes the effect of velocity filtering cut-off frequency on the Z-width performance of haptic interfaces. Finite difference method (FDM) cascaded with a low pass filter is the most commonly used technique for estimating velocity from position data in haptic interfaces. So far, there is no prescribed method for obtaining the FDM + filter cut-off frequency that will maximize Z-width performance. We present a simulation based method to demonstrate that there exists such an ideal FDM + filter cut-off frequency, and that it can be predicted by numerical simulation based on an identified model of a haptic interface. Experiments are conducted on a single degree-of-freedom (DOF) linear haptic interface to validate the simulation results.

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A Method for Selecting Velocity Filter Cutoff Frequency for Maximizing Impedance Width Performance in Haptic Interfaces

Volume 2: Control, Monitoring, and Energy Harvesting of Vibratory Systems; Cooperative and Networked Control; Delay Systems; Dynamical Modeling and Diagnostics in Biomedical Systems; Estimation and Id of Energy Systems; Fault Detection; Flow and Thermal Systems; Haptics and Hand Motion; Human Assistive Systems and Wearable Robots; Instrumentation and Characterization in Bio-Systems; Intelligent Transportation Systems; Linear Systems and Robust Control; Marine Vehicles; Nonholonomic Systems ◽

10.1115/dscc2013-3701 ◽

2013 ◽

Author(s):

Vinay Chawda ◽

Ozkan Celik ◽

Marcia K. O’Malley

Keyword(s):

Cutoff Frequency ◽

Haptic Interface ◽

Haptic Interfaces ◽

Simulation Experiments ◽

Single Degree Of Freedom ◽

Single Degree ◽

Simulation Based ◽

Position Data ◽

Simulation Results ◽

Velocity Filtering

This paper analyzes the effect of velocity filtering cut-off frequency on the Z-width performance in haptic interfaces. Finite Difference Method (FDM) cascaded with a lowpass filter is the most commonly used technique for estimating velocity from position data in haptic interfaces. So far, there is no prescribed method for obtaining the FDM+filter cut-off frequency that will maximize the Z-width performance. We present a simulation based method to demonstrate that there exists such an ideal FDM+filter cut-off frequency, and that it can be predicted by numerical simulation. Experiments are conducted on a single degree-of-freedom linear haptic interface to validate the simulation results.

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Stabilization of Magnetic Suspension System by Using Only a First-Order Reset Element without a Derivative Element

Actuators ◽

10.3390/act8010024 ◽

2019 ◽

Vol 8 (1) ◽

pp. 24 ◽

Cited By ~ 1

Author(s):

Yuji Ishino ◽

Takeshi Mizuno ◽

Masaya Takasaki ◽

Daisuke Yamaguchi

Keyword(s):

Suspension System ◽

Magnetic Suspension ◽

Pass Filter ◽

Low Pass Filter ◽

Single Degree Of Freedom ◽

Transient Characteristics ◽

First Order ◽

Single Degree ◽

Low Pass ◽

Magnetic Suspension System

The stabilization of a magnetic suspension system is achieved by using a low-pass filter (LPF) with a nonlinear integrator without any other element. A proportional-derivative (PD) control is commonly used as the simplest method of stabilizing a magnetic suspension system. Meanwhile, a first-order reset element (FORE) was applied to improve transient characteristics. The original FORE was a first-order LPF with a nonlinear reset integrator element. A magnetic suspension system cannot be stabilized by a linear LPF, nor the original FORE. In this work, the reset conditions of the FORE were modified for magnetic suspension. This modified FORE succeeded in stabilizing a magnetic suspension system. The efficacy of the modified FORE was demonstrated by simulations and experiments. A single degree of freedom magnetic suspension system was used in the experiment.

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Robust Sliding Mode Control of a Unipolar Power Inverter

Energies ◽

10.3390/en14175405 ◽

2021 ◽

Vol 14 (17) ◽

pp. 5405

Author(s):

Muhammad Awais ◽

Abdul Rehman Yasin ◽

Mudassar Riaz ◽

Bilal Saqib ◽

Saba Zia ◽

...

Keyword(s):

Electromagnetic Interference ◽

Sliding Mode ◽

Practical Implementation ◽

Switching Frequency ◽

Sigmoid Function ◽

Pass Filter ◽

Low Pass Filter ◽

Pulse Width Modulated ◽

Simulation Based ◽

Low Pass

The key issue in the practical implementation of the sliding mode (SM) control–based power inverter is the variable switching frequency. This variable switching frequency not only induces electromagnetic interference (EMI) noise, but also reduces the efficiency of the inverter, as the size of the inductor and capacitor does not alter in tandem with this variable frequency. In this context, fixed switching frequency–based SM control techniques are proposed; however, some of them are too complex, while others compromise the inherent properties of SM control. In this research, a fixed frequency SM controller is proposed, which is based on the novel low-pass filter extraction of the discontinuous control signal. This allows the technique to be implemented with fewer hardware components, thus reducing the complications of implementation, while maintaining the robustness and parametric invariance of SM control. A simulation-based comparison with an existing pulse width modulated (PWM) SM controller is presented as the benchmark. In comparison with the sigmoid function SM controller, an improvement of 50% in the settling time along with zero steady-state errors and a further 37% and 42% improvement in the undershoot and overshoot, respectively, is reported in the simulation. A hardware setup is established to validate the proposed technique, which substantiates the simulation results and its disturbance rejection properties.

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