Rapid Prototyping of a Micromotor with an Optical Rotary Encoder

WITHDRAWN: Implementation dc motor as servomotor by using arduino and optical rotary encoder

UV imprint fabrication of polymeric scales for optical rotary encoders

Optical encoders are mainly used in modern motion servo systems for high-resolution and reliable position and velocity feedback. Pseudorandom optical rotary encoders are single-track and use a serial pseudorandom binary code to measure absolute position. The realization and analysis of such a rotary encoder with advanced code scanning and error detection techniques, as well as an improved redundancy in operation, are presented. A presented serial code reading solution uses two phase-shifted code tracks and two optical encoder modules. So, the realized encoder, hybrid in nature, provides “output on demand” and more or less reliable position information using very efficient error checking. Compared to a standard absolute encoder, this encoder requires a smaller code disc, facilitates installation, has greater flexibility in operation, and is less sensitive to external influences.

This paper introduces a new design scheme of an ultra high-speed permanent magnet synchronous motor (PMSM) that enables utilization of an open-loop control. Theoretical analyses and both simulation and experimental results validate the proposed design technique and its effectiveness. Employing permanent magnet Nd-Fe-B, a PMSM offers the advantages of high efficiency and high power density compared to other types of motors. By using slotless stator structure, the cogging torque due to the slots is eliminated, and losses caused in the rotor surface are also eliminated. However, most PMSMs are inherently unstable and correspondingly require a closed-loop control system or damper windings in the rotor to assure the synchronization of motion of the rotor with the stator frequency applied. Design of a closed-loop control system is technically very challenging since a feedback sensor such as an optical encoder or a hall sensor is not reliable at ultra highspeed of 200,000 rpm. The ultrahigh speed PMSM system achieves 90.7% efficiency at 200,000 rpm while the stability of the motor can be guaranteed over its operating speed range under the open-loop controller.

This paper presents an adaptive controller for CIRIS (Compositional InfraRed Interferometric Spectrometer) implemented on a stand-alone field programmable gate array (FPGA) architecture with emphasis on space applications in radiation environments such as Europa. CIRIS is a novel take on traditional Fourier Transform Spectrometers (FTS) and replaces linearly moving mirrors (characteristic of Michelson interferometers) with a constant-velocity rotating refractor to variably phase shift and alter the path length of incoming light. This design allows for a compact and robust device, making it ideal for spaceborne measurements in the near-IR to thermal-IR band (2–12 µm) on planetary exploration missions. The instrument's embedded microcontroller is implemented on a VIRTEX-5 FPGA and a PowerPC with the aim of sampling the instrument's detector and optical rotary encoder in order to construct an interferogram. Subsequent signal processing provides spectral immunity from the noise effects of radiation encountered during space flight to destinations such as Europa. A variety of signal processing techniques, including radiation peak removal, resampling, Fast Fourier Transform (FFT), filtering, dispersion correction, and spectral calibration processes are applied in real-time to compose the sample spectrum. The instrument's FPGA controller is demonstrated with the FTS to highlight its suitability for implementation in space systems.

图像式光电编码器的测角技术及其硬件实现

Effect of soaking temperature on concentration of rare-earth ions in the optical fiber core during solution doping process was investigated. The dopant concentration of Er<SUP>3+</SUP> and Ho<SUP>3+</SUP> in the preforms and the fibers measured by the electron probe microanalysis and the optical spectrum analyzer was found to increase with decreasing the soaking temperature. The increase in the concentration of the Er<SUP>3+</SUP> and the Ho<SUP>3+</SUP> was attributed to the precipitation of the dopants due to the decrease in the solubility by decreasing the temperature.

A novel concept for an all optical absolute position encoder whose sensing unit uses only passive elements is presented. Optical delay fiber loops are used to multiplex sensing channels. The device can be interrogated from a distant location using a single optical fiber which can be several kilometers long. Absolute position encoding is achieved by analog modulation of light intensity with well studied multiple slit patterns.

Stroke leads to serious long-term disability. Electrical epidural cortical stimulation has made significant improvements in stroke rehabilitation therapy. We developed a preliminary wireless implantable passive interface, which consists of a stimulating surface electrode, receiving coil, and single flexible passive demodulated circuit printed by flexible printed circuit (FPC) technique and output pulse voltage stimulus by inductively coupling an external circuit. The wireless implantable board was implanted in cats’ unilateral epidural space for electrical stimulation of the primary visual cortex (V1) while the evoked responses were recorded on the contralateral V1 using a needle electrode. The wireless implantable board output stable monophasic voltage stimuli. The amplitude of the monophasic voltage output could be adjusted by controlling the voltage of the transmitter circuit within a range of 5–20 V. In acute experiment, cortico-cortical evoked potential (CCEP) response was recorded on the contralateral V1. The amplitude of N2 in CCEP was modulated by adjusting the stimulation intensity of the wireless interface. These results demonstrated that a wireless interface based on a microcoil array can offer a valuable tool for researchers to explore electrical stimulation in research and the dura mater-electrode interface can effectively transmit electrical stimulation.

Ultra-short optical pulse shaping based on time-to-space conversion has been widelydemonstrated by usingfree-space optics with diffraction grating pairs and lenses. We have proposed time-to-space conversion opticalsignal processing using an arrayed-waveguide grating. The arrayed-waveguide grating system has the advantagesof a long time window, and well suites to handle subpico-to several picosecond pulses. Moreover, it iscompact, compatible with fiber optics, and can be integrated with functional photonic devices. We introduceseveral applications of this technology to terabit communication systems, such as pulse shaping, dispersioncompensation, differential processing, optical phase-shift keying detection and optical CDM encoder and decoder.

This paper proposes an enhanced Model Predictive Direct Speed Control (MPDSC) framework for Permanent Magnet Synchronous Motor (PMSM) drives, integrating duty ratio optimization and load torque disturbance compensation to significantly improve both transient and steady-state performance. Traditional finite-control-set MPC strategies, which apply a single voltage vector per sampling interval, often suffer from steady-state ripples, elevated total harmonic distortion (THD), and high computational complexity due to exhaustive switching evaluations. The proposed approach addresses these limitations through a novel dual-stage cost function structure: the first cost function optimizes dynamic response via predictive control of speed error, while the second adaptively minimizes torque ripple and harmonic distortion by adjusting the active–zero voltage vector duty ratio without the need for manual weight tuning. Robustness against time-varying disturbances is further enhanced by integrating a real-time load torque observer into the control loop. The scheme is validated through both MATLAB/Simulink R2020a simulations and real-time experimental testing on a dSPACE 1202 rapid control prototyping platform across small- and large-scale PMSM configurations. Experimental results confirm that the proposed controller achieves a transient speed deviation of just 0.004%, a steady-state ripple of 0.01 rpm, and torque ripple as low as 0.0124 Nm, with THD reduced to approximately 5.5%. The duty ratio-based predictive modulation ensures faster settling time, improved current quality, and greater immunity to load torque disturbances compared to recent duty-ratio MPC implementations. These findings highlight the proposed DR-MPDSC as a computationally efficient and experimentally validated solution for next-generation PMSM drive systems in automotive and industrial domains.

This paper presented a vector controlled drives of permanent Magnet Synchronous Motor (PMSM) by using Proportional-Integral (PI) Speed controller based dSPACE implementation. The concept of vector control is applied to PMSM to obtain linear dynamics similar to that of a DC motor. The model consist of two control loops, hysteresis current controller is used for inner loop current control and PI controller for outer loop speed control. PI speed controller selected due to simplicity compare to fuzzy, neutral etc. to make sure dSPACE DS1103 successfully implemented. The PMSM vector control algorithm for a theoretical basic has been verified by experimental results and created a rapid control prototype environment by using MATLAB/ Simulink and the DS1103 DSP of dSPACE.

High-intensity focused ultrasound (HIFU) is a promising treatment method for many common cancers, including prostate cancer. Magnetic resonance image (MRI) guidance of HIFU permits targeting and monitoring of therapy. A prototype MRI-compatible positioning device that navigates a HIFU transducer was designed, fabricated and tested. The positioning device has two PC-controlled and one manually driven stage that allow endorectal access to the prostate. The positioning device was constructed using a 3-D rapid prototype manufacturing device. Software was developed that controls the motion of the positioning device and enables activation of a HIFU transducer. In vitro testing of the system was performed in a 1.5T MRI scanner using ex vivo turkey tissue. Optical encoders were employed to enhance the accuracy of this positioning device. The positioning device was successfully tested for MRI compatibility. The movement error of the positioning device is approximately 20 [Formula: see text]m. The robot has the ability to accurately move the transducer for creation of discrete and overlapping lesions. An MRI-compatible HIFU positioning system was developed that has the ability to create thermal lesions with MRI guidance for endorectal treatment of prostate cancer.

As demand for customized specialty fibers grows, standardized production methods face challenges. This article reviews industry standards and discusses potentially disruptive techniques that enable rapid prototyping and fabrication of optical fiber devices. Furthermore, we showcase laser powder deposition's (LPD) potential for additive manufacturing (AM) of customized glass structures. In the case of, for example, fiber preforms, although the feasible size is smaller than the industry standard, utilizing laser‐based manufacturing techniques for a small batch production presents an attractive avenue for rapid prototyping and expedites material and design optimization. In the realm of AM of glass, LPD offers numerous benefits, including minimal shrinkage, high densification, and the ability to tailor glass composition to achieve desired optical properties. The article reviews the latest achievements and highlights future directions in this technology.

We produced a PbTe quantum dot core doped optical fiber with tellurite glasses intended to be used in highly nonlinear ultrafast optical devices capable to operate at the optical communication window at 1300 and 1500 nm wavelength region. Attenuation peaks of the optical fiber depends on the heat treatment time as expected for dots growth and covered the whole mid infrared region near 1500 nm. The optical fiber preform was made with the rod-in-tube method and the fiber was produced with a 4 m high Heatway drawing tower. The optical fiber core can be heavily doped because tellurite glasses solubility for PbTe quantum dots is order of magnitude higher than borosilicate and phosphate glasses, for example. In order to match all the requirements for core-clad optical fibers we studied undoped and doped tellurite glasses optical and thermophysical properties as a function of the glass composition. We also followed the growth kinetics of the quantum dots by High Resolution Transmission Electron Microscopy in the bulk glass matrix and the optical fiber.