Trajectory Generation for Stair Ascent Walking using Rayleigh Oscillator

This paper describes a trajectory generation technique for stair-ascent walking. The knee, hip and ankle joint trajectory during stair ascent are generated using mutually coupled, nonlinear oscillators. The parameters of the oscillators are tuned using the harmonic balance method, which converts the nonlinear differential equations to a set of algebraic equations. Fourier analysis of data generated by stair-ascent walking is performed to extract the amplitude and the phase of the dominant frequency components for each joint trajectory. The solution for the oscillator is assumed to be a sinusoidal wave and then by harmonic balance method the parameters of the oscillator are found. Each oscillator is responsible for generating a single frequency component with a specific phase and amplitude. The complete trajectory is obtained by summing the output of the oscillators that are relevant to one joint and the coupling maintains the phase relationship between the oscillators

PID Stabilization of a Position-Controlled Robot Manipulator Acting Independently of in Collaboration with Human Arm

In this paper we develop framework for PID stabilization of a robot manipulator when using an object independently or in collaboration with a human arm. In both applications, the manipulator is equipped with a wrist sensor represented by an impedance. A second order manipulator transfer function along each coordinate direction is assumed. The aim of the paper is to design a PID controller when measurement of contact force, available via wrist sensor, is used to command the position controlled manipulator to a desired position and/or force profile. Necessary and sufficient conditions for stability of the closed loop system are developed using Hermite-Biehler Theorems. The theorems have been used to analyze stability of polynomials defined over the set of real numbers. Analgorithm for synthesis ofPID controllers using linear matrix inequalities is developed. The theoretical framework presented in this paper can be easily adapted to other low order manipulator transfer functions

Causes, Effects, and Remedies in Conflict Management

While workplace conflicts have been widely studied in the literature, this researchprovides a holistic view of the causes and effects of such, and how managers or amanagement can resolve the conflicts among their teams and organization througha detailed, multidimensional framework carried out on one of the biggest textilefirms of Pakistan. With an initial sample of 145 respondents, 37 questionnaireswere dropped because of invalid and incomplete answers; therefore, the studywas carried out on 108 respondents. Conflicts are a part of human nature, butmanagement should play an important role in dealing with these issues, as therecan be enormous chances of conflicts due to a diverse workforce. Conflict alsoresults in poor work performance and low productivity; therefore, it’s suggestedto create teams or groups which may encourage a competitive culture in theorganization. Additionally, a few remedies are identified, which may resolve someissues; managers must look at those techniques for a better culture.&nbsp

Incidence of External Ear Canal Folliculitis

To analyze the incidence of ExternalEar Canal Folliculitis (EECF) in adult population ofdistrict Bannu.Methods: In this descriptive study 100 patientswith ear ache, presented in four quarters of the yearwere included. Complaints, and findings on physicalexamination including otoscopy results, diagnosiswere recorded. Inclusion criteria was adults (18+)with ear pain as a major complaint. We included thecases with another major complaint only when itwas related to the ear pain (e.g. referred pain fromsinusitis, tonsillitis).Exclusion criteria was antibiotictreatment in the last 10 days was marked asexclusion criteria. Both the rates of external ear canalfolliculitis and the rate of Non-external ear canalfolliculitis were compared. We also subdivided thedifferent diagnostics under the title "folliculitischannel of the non-outer ear." The prevalence of theexternal ear canal folliculitis diagnosis wascalculated, including subdivisionby sex and agegroups, by location in the ear canal includingposterior vs. anterior and by the quarters of the year.Results: 35% of cases represented EECF wereincluded. The ratio of male to female was observed3: 2. The condition was maximum in 2nd& 3rd quarterof the year where as it was minimal in 1st and 4thquarters. Earache in adult patients was the mostcommon principal inflammation, which is generallytermed as EECF.Conclusion: Different factors are being involvedin its prevalence including poor hygiene, overcrowding, bath in a contaminated water, hotweather, ear wax and lack of specialized care. Sincetreatment is only possible upon clinical diagnosis,doctors will likely be more reserved about oralantibiotics if EECF can be diagnosed appropriatel

Improving Inverse Dynamics Accuracy in a Planar Walking Model Based on Stable Reference Point

Physiologically and biomechanically, the human body represents a complicated system with an abundance of degrees of freedom (DOF). When developing mathematical representations of the body, a researcher has to decide on how many of those DOF to include in the model. Though accuracy can be enhanced at the cost of complexity by including more DOF, their necessity must be rigorously examined. In this study a planar seven-segment human body walking model with single DOF joints was developed. A reference point was added to the model to track the body’s global position while moving. Due to the kinematic instability of the pelvis, the top of the head was selected as the reference point, which also assimilates the vestibular sensor position. Inverse dynamics methods were used to formulate and solve the equations of motion based on Newton-Euler formulae. The torques and ground reaction forces generated by the planar model during a regular gait cycle were compared with similar results from a more complex three-dimensional OpenSim model with muscles, which resulted in correlation errors in the range of 0.9–0.98. The close comparison between the two torque outputs supports the use of planar models in gait studies

A New Technique to Improve the Operation of Prosthetic Limbs during Muscle Fatigue

Prosthetic limbs hold a promise to renew the quality of life for the amputee. Neural commands are decoded via a classifier to generate control signals for the prosthetic devices. In the literature, many challenges and limitations have been identified that affect the prosthesis operation. One such drawback is muscle fatigue which degrades the surface electromyogram (sEMG) signals, and consequently, the performance of the deployed classification algorithm declines from 90% to 50% of average accuracy. We used a new technique using the Linear Discrimination Analysis (LDA) algorithm and the muscle synergy-based task discrimination (MSD) algorithm to improve the classification accuracy. In this technique, during muscles contraction/fatigue, we used the LDA algorithms in the beginning and the MSD algorithms later. The applied technique exhibited better movement classification performance during normal and muscle fatigue conditions. However, more work needs to be done to effectively solve the muscle fatigue problem in prosthesis design