Design and Implementation of Position Estimator Algorithm on Voice Coil Motor

Voice Coil Motors (VCMs) have been an inevitable element in the mechanisms that have been used for precise positioning in the applications like 3D printing., micro-stereolithography., etc. These voice coil motors translate in a linear direction and require a high accuracy position sensor that amounts for a major part in the budget. In this research work., an effort has been made to design and implement an algorithm that would predict the displacement of VCM and eliminate the need of high cost sensors. VCM was integrated with dSPACE DS1104 R&D controller via linear current amplifier (LCAM) which acts as a driver circuit for VCM. Sine input was given to VCM with various amplitude and frequency and the corresponding displacement is measured by using linear variable differential transformer (LVDT). The position estimator algorithm is also implemented at the same time on VCM and its output is compared with that of LVDT. It is observed that there is 97.8 % accuracy in between algorithm output and LVDT output. Further., PID controller is used in integration with the novel algorithm to minimize the error. The estimator algorithm is tested for various amplitudes and frequencies and it is found that it has a very good agreement of 99.2% with the actual displacement measured with the help of LVDT

Design and Experimental Validation of Voice Coil Motor for High Precision Applications

Flexural structures are extensively beneficial when differentiated with conventional inflexible body structures where point accuracy positioning is strongly required extending in the range of microns. To fulfill clear and accurate positioning requirements, we come up with the solution of voice coil motors (VCM) with position estimator algorithm. Appropriate magnet and coil assembly is designed by considering the ultimate force for the application. Voice coil motor components are fabricated on milling machine and then assembled. This VCM is incorporated with dSPACE DS1104 R&D controller with the help of linear current amplifier (LCAM) which controls VCM with respect to desired amplitude and frequency. Displacement of coil of VCM is detected with respect to fixed magnet by using linear variable differential transformer (LVDT) which generates analog voltage signal in relation with motion of coil. Static characteristic such as stiffness is determined using force-deflection plot and dynamic characteristic like damping factor and frequency response are estimated with the help of transient response obtained by providing step input to the motor. Further, PID controller is implemented on this VCM and it is error observed is less than ±0.S microns

Exploring access to HIV-related services and programmatic gaps for Men having Sex with Men (MSM) in rural India- a qualitative study.

BackgroundDespite the Link Worker Scheme to address the HIV risk and vulnerabilities in rural areas, reaching out to unreached men having sex with men (MSM) remains a challenge in rural India. This study explored issues around health care access and programmatic gaps among MSM in rural settings of India.MethodsWe conducted eight Focused Group Discussions (FGDs), 20 Key Informant Interviews (KIIs), and 20 In-Depth Interviews (IDIs) in four rural sites in Maharashtra, Odisha, Madhya Pradesh, and Uttar Pradesh between November 2018 and September 2019. The data in the local language were audio-recorded, transcribed, and translated. Data were analyzed in NVivo version 11.0 software using the grounded theory approach.ResultsPrimary barriers to health care access were lack of knowledge, myths and misconceptions, not having faith in the quality of services, program invisibility in a rural setting, and anticipated stigma at government health facilities. Government-targeted intervention services did not seem to be optimally advertised in rural areas as MSM showed a lack of information about it. Those who knew reported not accessing the available government facilities due to lack of ambient services, fear of the stigma transforming into fear of breach of confidentiality. One MSM from Odisha expressed, "…they get fear to go to the hospital because they know that hospital will not maintain confidentiality because they are local people. If society will know about them, then family life will be disturbed" [OR-R-KI-04]. Participants expressed the desire for services similar to those provided by the Accredited Social Health Activists (ASHA), frontline health workers for MSM.ConclusionProgramme invisibility emerges as the most critical issue for rural and young MSM. Adolescent and panthis emerged as Hidden MSM and they need focused attention from the programme. The need for village-level workers such as ASHA specifically for the MSM population emerged. MSM-friendly health clinics would help to improve healthcare access in rural MSMs under Sexual and Reproductive Health Care