Low-pass filter cutoff frequency affects sacral-mounted inertial measurement unit estimations of peak vertical ground reaction force and contact time during treadmill running

2021 ◽  
Vol 119 ◽  
pp. 110323
Author(s):  
Evan M. Day ◽  
Ryan S. Alcantara ◽  
Michael A. McGeehan ◽  
Alena M. Grabowski ◽  
Michael E. Hahn
Keyword(s):  
Inertial Measurement Unit ◽  
Reaction Force ◽  
Cutoff Frequency ◽  
Treadmill Running ◽  
Measurement Unit ◽  
Vertical Ground Reaction Force ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Vertical Ground

How the Integral Operations in INS Algorithms Overshadow the Contributions of IMU Signal Denoising Using Low-Pass Filters

2013 ◽  
Vol 66 (6) ◽  
pp. 837-858 ◽  
Author(s):  
Yalong Ban ◽  
Quan Zhang ◽  
Xiaoji Niu ◽  
Wenfei Guo ◽  
Hongping Zhang ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Signal Denoising ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Static Data ◽  
Low Pass ◽  
Low Pass Filters ◽  
Navigation Accuracy

This paper has made a comprehensive investigation of the contribution of inertial measurement unit (IMU) signal denoising in terms of navigation accuracy, through theoretical analysis, simulations and real tests. Analysis shows that the integral step in the inertial navigation system (INS) algorithm is essentially equivalent to a super low-pass filter (LPF), whose filtering strength is related to the integral time of the INS. Therefore the contribution of the IMU denoising filter is almost completely overshadowed by the effect of the integral step for normal navigation cases. The theoretical analysis result was further verified by the simulations with an example of inertial angle estimation and by real tests of INS and GPS/INS systems. Results showed that the IMU signal denoising cannot bring observable improvement to INS or GPS/INS systems. This conclusion is strictly valid in the condition that the equivalent cut-off frequency of the integral step (which equals the reciprocal of the INS working alone time) is lower than the cut-off frequency of the denoising filter, which is the usual case for INS applications (except for some static data processing such as the stationary alignment of INS).

Design and Simulation of Switched Capacitor Filter for Speed Change Parameter Converter

2013 ◽  
Vol 562-565 ◽  
pp. 1132-1136
Author(s):  
Xiao Wei Liu ◽  
Jian Yang ◽  
Song Chen ◽  
Liang Liu ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Stop Band ◽  
Cutoff Frequency ◽  
Rapid Change ◽  
Pass Band ◽  
Cmos Process ◽  
Switched Capacitor ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
The Time Domain

In this paper, we design a high-order switched capacitor filter for rapid change parameter converter. This design uses a structure which consists of three biquads filter sub-units. The design is a 6th-order SC elliptic low-pass filter, and the sample frequency is 250 kHz. By the MATLAB Simulink simulation, the system can meet the design requirements in the time domain. In this paper, the 6th-order switched capacitor elliptic low-pass filter was implemented under 0.5 um CMOS process and simulated in Cadence. The final simulation results show that the pass-band cutoff frequency is 10 kHz, and the maximum pass-band ripple is about 0.106 dB. The stop-band cutoff frequency is 20 kHz, and the minimum stop-band attenuation is 74.78 dB.

Improved Stator Flux Estimation for Direct Torque Control of Induction Motor Drives

2016 ◽  
Vol 7 (4) ◽  
pp. 1049
Author(s):  
Yahya Ahmed Alamri ◽  
Nik Rumzi Nik Idris ◽  
Ibrahim Mohd. Alsofyani ◽  
Tole Sutikno
Keyword(s):  
Induction Motor ◽  
Cutoff Frequency ◽  
Direct Torque Control ◽  
Motor Drives ◽  
Torque Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Flux Estimation ◽  
Stator Flux

<p>Stator flux estimation using voltage model is basically the integration of the induced stator back electromotive force (emf) signal. In practical implementation the pure integration is replaced by a low pass filter to avoid the DC drift and saturation problems at the integrator output because of the initial condition error and the inevitable DC components in the back emf signal. However, the low pass filter introduces errors in the estimated stator flux which are significant at frequencies near or lower than the cutoff frequency. Also the DC components in the back emf signal are amplified at the low pass filter output by a factor equals to . Therefore, different integration algorithms have been proposed to improve the stator flux estimation at steady state and transient conditions. In this paper a new algorithm for stator flux estimation is proposed for direct torque control (DTC) of induction motor drives. The proposed algorithm is composed of a second order high pass filter and an integrator which can effectively eliminates the effect of the error initial condition and the DC components. The amplitude and phase errors compensation algorithm is selected such that the steady state frequency response amplitude and phase angle are equivalent to that of the pure integrator and the multiplication and division by stator frequency are avoided. Also the cutoff frequency selection is improved; even small value can filter out the DC components in the back emf signal. The simulation results show the improved performance of the induction motor direct torque control drive with the proposed stator flux estimation algorithm. The simulation results are verified by the experimental results.</p>

scholarly journals A CMOS Low Pass Filter for SoC Lock-in-Based Measurement Devices

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5173 ◽  
Author(s):  
Jorge Pérez-Bailón ◽  
Belén Calvo ◽  
Nicolás Medrano
Keyword(s):  
Dynamic Range ◽  
Current Trend ◽  
Cutoff Frequency ◽  
Oxide Semiconductor ◽  
Constant Current ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Compact Size ◽  
Low Pass ◽  
Lock In

This paper presents a fully integrated Gm–C low pass filter (LPF) based on a current steering Gm reduction-tuning technique, specifically designed to operate as the output stage of a SoC lock-in amplifier. To validate this proposal, a first-order and a second-order single-ended topology were integrated into a 1.8 V to 0.18 µm CMOS (Complementary Metal-Oxide-Semiconductor) process, showing experimentally a tuneable cutoff frequency that spanned five orders of magnitude, from tens of mHz to kHz, with a constant current consumption (below 3 µA/pole), compact size (<0.0140 mm2/pole), and a dynamic range better than 70 dB. Compared to state-of-the-art solutions, the proposed approach exhibited very competitive performances while simultaneously fully satisfying the demanding requirements of on-chip portable measurement systems in terms of highly efficient area and power. This is of special relevance, taking into account the current trend towards multichannel instruments to process sensor arrays, as the total area and power consumption will be proportional to the number of channels.

The Design of Gm-C Low-Pass Filter for Micromachined Gyroscope

2014 ◽  
Vol 609-610 ◽  
pp. 1072-1076
Author(s):  
Qiu Ye Lv ◽  
Chong He ◽  
Wen Jie Fan ◽  
Yu Feng Zhang ◽  
Xiao Wei Liu
Keyword(s):  
Process Model ◽  
Stop Band ◽  
Cutoff Frequency ◽  
Harmonic Distortion ◽  
Cmos Process ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Simulation Results ◽  
Micromachined Gyroscope

In this Paper, a 4th-Order Low-Pass Gm-C Filter is Presented. for the Design of Operational Tranconductance Amplifier(OTA), it Adopts the Techniques of Current Division and Current Cancellation. these Techniques can Help to Achieve a Low Transconductance Value. for the Architecture of the 4th-Order Gm-C Filter, it Consists of Two Biquads. the Two Biquads are Cascade Connected. the Gm-C Low-Pass Filter has been Implemented under 0.5 μm CMOS Process Model. the Final Simulation Results Show the Cutoff Frequency of the Filter is 100Hz and the Stop-Band Attenuation is Larger than 60dB. the Power Consumption is Lower than 1mW and the Total Harmonic Distortion(THD) is -55dB.

The Method on Acceleration Extraction from Strapdown Airborne Scalar Gravimeter Based on Flight Dynamics

2012 ◽  
Vol 591-593 ◽  
pp. 2152-2156 ◽  
Author(s):  
Shao Kun Cai ◽  
Kai Dong Zhang ◽  
Mei Ping Wu ◽  
Yang Ming Huang
Keyword(s):  
Measurement Errors ◽  
Cutoff Frequency ◽  
Flight Dynamics ◽  
Error Model ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

Combining with the error model of strapdown airborne scalar gravimetry, the paper analyses the natural motions of the aircraft, and then discusses how those natural motions of the aircraft influence the airborne scalar gravimetry. The spectra characteristic of measurement errors of the strapdown airborne scalar gravimetry can be obtained, and its relation with natural motions of the aircraft is demonstrated. As a result, we can determine the cutoff frequency of low-pass filter through the characteristic of the natural motions of the aircraft, the cutoff frequency is very important for acceleration extraction from the strapdown airborne scalar gravimeter.

scholarly journals A Compact Planar Low-Pass Filter Based on SRR-Metamateria

2018 ◽  
Vol 8 (6) ◽  
pp. 4972
Author(s):  
Badr Nasiri ◽  
Ahmed Errkik ◽  
Jamal Zbitou ◽  
Abdelali Tajmouati ◽  
Larbi El Abdellaoui ◽  
...  
Keyword(s):  
Cutoff Frequency ◽  
Total Surface Area ◽  
Ring Resonators ◽  
Split Ring ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Attenuation Level ◽  
Low Pass ◽  
Novel Design ◽  
Good Agreement

In this work, a novel design of a Microstrip Low-pass filter based on metamaterial square split ring resonators (SRRs) is proposed. The SRRs has been added to obtain a reduced size and high performances. The filter is designed on an FR-4 substrate having a thickness of 1.6mm, a dielectric constant of 4.4 and loss tangent of 0.025. The proposed low-pass filter is characterized by a cutoff frequency of 2.4 GHz and an attenuation level below than -20dB in the stopband. The LPF is designed, simulated and optimized by using two electromagnetic solvers CST microwave studio and ADS. The computed results obtained by both solvers are in good agreement. The total surface area of the proposed circuit is 18x18mm2 excluding the feed line, its size is miniaturized by 40% compared to the conventional filter. The experimental results illustrate that the filter achieves very good electrical performances in the passband with a low insertion loss of 0.2 dB. Moreover, a suppression level can reach more than 35 dB in the rejected band.

scholarly journals Low insertion loss of surface mount device low pass filter at 700 MHz

2019 ◽  
Vol 8 (2) ◽  
pp. 382-388
Author(s):  
Khairil Anuar Khairi ◽  
Mohd Faizal Jamlos ◽  
Surentiran Padmanathan ◽  
Mohd Aminudin Jamlos ◽  
Muammar Mohamad Isa
Keyword(s):  
Transition Region ◽  
Insertion Loss ◽  
Power Supply ◽  
Cutoff Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Surface Mount ◽  
Low Pass ◽  
Low Insertion Loss ◽  
Image Frequency

The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surface Mount Device (SMD) LPF with cutoff frequency at 700 MHz. Fabricated LPF is consisted of four PCB layers which components of SMD are soldered on the top layer. Another three layers is for grounding and shielding, power supply and grounding void. The four layers is crucial to avoid interference between components. The research has find out that the momentum simulation is definitely required to improve the signals response compared to a normal simulation by ADS software. The comparison between momentum simulated versus measured and normal simulated versus measured is 0.2 dB and 29 dB correspondingly. Such huge difference leads to conclusion that momentum simulation is saving time without having much struggles and efforts to get optimum readings. The Proposed SMD LPF has a very low insertion loss of 0.965dB with a transition region of 195 MHz which is good steepness to avoid any image frequency.

Sign in / Sign up

Export Citation Format

Share Document