- 标题
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- 实验方案
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Robot Operating System (ROS) Compatible Low Cost Rotating Light Detection and Ranging (Lidar) Design
摘要： Robot Operating system (ROS) is collection of software frameworks for robot software development. Researchers that work with ROS will have an opportunity to use or to be exact to reuse any software framework from another researcher as long as they use a similar robot platform, or similar device that has been include in the ROS. This paper present a design for a low cost rotating Lidar that compatible with ROS. As all we know distance measurement is the basic for building an autonomous capability for robots. Rotating lidar is among one the most popular device used to acquire this kind of information. However most of them are not suitable for low budget project because of their high cost. The design presented here tries to build a low cost rotating lidar based on Lidar Lite device with the compatibility with the ROS. The design incorporate a control board based on a microcontroller.
关键词： rotating,distance measurement,low cost,ROS,Lidar
更新于2025-09-09 09:28:46
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Point of care sensing and biosensing using ambient light sensor of smartphone: Critical review
摘要： In the present review article, the ubiquitous application of ambient light sensor (ALS) of a smartphone towards development of light weight, field-portable and low-cost devices have been summarized. Compared to the computational imaging based technique using phone’s camera for detection of target analyte, there are certain advantages of utilizing ALS of smartphone in terms of low sample volume, ease in device fabrication and simplicity in optical design. Parallel to CMOS image sensor of the smartphone camera, the ALS of a smartphone can emerge as a potential in-built sensor for detection and analysis of different types of analytes that can open new opportunities towards development of low cost sensing devices.
关键词： Point of care sensing,Smartphone,Biosensing,Low-cost devices,Ambient Light Sensor
更新于2025-09-09 09:28:46
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Boosting the efficiency of carbon-based planar CsPbBr3 perovskite solar cells by a modified multistep spin-coating technique and interface engineering
摘要： All-inorganic CsPbBr3 perovskite solar cells (PSCs) have attracted tremendous attentions in the photovoltaic field these days in view of their outstanding stability, especially thermal stability. However, the bromide-rich perovskite, such as CsPbBr3, always suffer from a low phase-purity and poor morphology synthesized by traditional two-step deposition route. Herein, we demonstrate a facile multistep spin-coating strategy to fabricate high-quality CsPbBr3 films on the low-temperature processed compact TiO2 (c-TiO2) electron transport layer (ETL) of the carbon-based PSCs. As-prepared films exhibit more homogeneous with higher CsPbBr3-phase purity and larger average grain sizes up to 1 μm, compared to those prepared through traditional two-step deposition process. The champion power conversion efficiency (PCE) of the planar CsPbBr3 PSC is boosted from 7.05% to 8.12%, getting an increase by 15.2%, due to the increased crystallinity and light-harvesting ability as well as reduced trap states of the CsPbBr3 film. To further enhance the device performance, a SnO2 thin layer with much higher carrier mobility than TiO2 is introduced to passivate the c-TiO2 ETL. It is found that the SnO2 layer can not only improve the surface morphology of the ETL, but also reduce the current shunting pathways in the c-TiO2. The TiO2/SnO2 bilayered ETL possesses a superior electron extraction capability, beneficial to the charge transport and suppression of the interfacial trap-assisted recombination. The best-performing TiO2/SnO2-based CsPbBr3 PSC delivers an excellent fill factor of 0.817 and a high PCE of 8.79%, which is the highest efficiency for planar CsPbBr3 PSCs reported to date. More importantly, the unencapsulated all-inorganic PSCs show a promising humidity and thermal stability with no decline in efficiency when stored in ambient air at room temperature (25 oC) for over 1000 h and 60 oC for one month, respectively. Our work pave the ways for practical applications of cost-effective, highly efficient and stable all-inorganic PSCs.
关键词： carbon-based,TiO2/SnO2,low cost,CsPbBr3,multistep spin-coating,high efficiency and stability
更新于2025-09-09 09:28:46
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A NOVEL POLARIZATION INDEPENDENT CHIPLESS RFID TAG USING MULTIPLE RESONATORS
摘要： A novel polarization independent RFID tag employing multiple resonators is proposed. The prototype of the tag is fabricated on a low-cost substrate of dielectric constant 4.4 and loss tangent 0.02. Designing a reader for chipless RFID is a hard task since both the polarization and operating frequency agility have to be implemented. The new tag design proposed in this paper is polarization independent, making the design of the reader easier. A prototype of a 3 bit data encoded tag is demonstrated using single structure which can be extended to any order by cascading. This new design is experimentally validated in the frequency domain using monostatic measurement with magnitude response to decode the information.
关键词： polarization independent,multiple resonators,low-cost substrate,chipless RFID tag,frequency domain
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Low-Cost High-Efficiency Single-Stage Solid-State Transformer for Lighting Applications
摘要： This paper presents a low-cost high-efficiency single-stage 480 Vrms to 264 Vrms solid-state transformer (SST) for lighting applications. The proposed SST is based on center-point-clamped (CPC) ac-ac buck converter topology. A comprehensive cost and efficiency optimization methodology is developed to help identify the most appropriate SST design across a design space comprising various switch structures, a range of operating frequencies, and different inductance values. For the selected implementation, a novel switching scheme is introduced that ensures smooth inductor current commutation during switching transitions, and also reduces zero-crossing distortion in the input current. Furthermore, an active voltage balancing scheme is developed to compensate for any imbalances between the two stacked input capacitors to ensure robust converter operation. A prototype 600-W solid-state transformer based on the proposed optimization, designed to operate at an input voltage of 480 Vrms and an output voltage of 264 Vrms is built and tested. The prototyped converter achieves a peak efficiency of 96%, maintains an efficiency of above 92% across a 3:1 output power range, and has a power density of 40 W/in3.
关键词： efficiency optimization,center-point-clamped converter,low cost converter design,ac-ac converter,active voltage balancing,cost optimization
更新于2025-09-04 15:30:14
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Low-cost, readily available 3D microscopy imaging system with variable focus spinner
摘要： A large open aperture in an optical system can capture high-resolution images but yields a shallow depth of ?eld. To overcome this issue, we investigated a low-cost, readily available method for retro?tting microscopy imaging systems to achieve 3D focus scanning in this study. Speci?cally, a procedure for fabricating variable focus spinners with dissimilar plates was introduced, and a sequence of 12 images was captured in di?erent focal planes. The image scale and phase were corrected, and the in-focus pixels were abstracted by employing the Laplacian operator. Finally, an all-in-focus sharp image was generated, and a depth map was obtained.
关键词： low-cost,image processing,depth of field,variable focus,3D microscopy
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - An Extremely Low-Cost Multi-Panel PV Emulator for Research and Education
摘要： Photovoltaic (PV) emulators are necessary tools for teaching research and development when actual PV panels cannot be used. Emulation can be used when design parameters such as size and quantity of PV resources required exceed the capacity of laboratories. Emulation schemes available today use expensive hardware and/or require software licenses. This paper presents a new PV emulator using the extremely low-cost real-time digital controller platform “Workbench”. The proposed scheme uses low-cost hardware built around a single DSP and a DC bench power supply to emulate PV panels which can be used to test other equipment such as grid-tied inverters, and/or MPPT controllers. The proposed scheme is modular, in that multiple such emulators can be externally series/parallel connected. Each emulator can also be con?gured to emulate a combination of series/parallel connected PVs.
关键词： Re-programmable,recon?gurable,real-time,modular,photovoltaic,low-cost
更新于2025-09-04 15:30:14
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Baking soda: an ultra-cheap and air stable electron injection layer for organic electronic devices
摘要： To realize high performance printed organic optoelectronic devices, the development of air-stable, cheap, and solution-processable electron injection layers (EILs) is urgently required to avoid the use of a low work-function metal electrode with poor air stability. We report sodium bicarbonate (baking soda, NaHCO3) as an efficient, low-cost, air-stable, and environmentally friendly EIL material in various printed organic electronic devices including organic solar cells (OSCs), organic light-emitting diodes (OLEDs), organic photodiodes (OPDs) and n-channel organic thin film transistors (OFETs). UV photoelectron spectroscopy results indicated that the work-function of various common electrodes used for organic devices such as ITO, Au, Al and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) decreased significantly by more than 1 eV following deposition of a thin NaHCO3 film. The performance and stability of these organic devices improved by around 15% overall with ultra-cheap, air stable EILs. In particular, high performance OSCs based on PTB7:PC71BM with a power conversion efficiency of 8.40% and solution processed OLEDs based on PVK:PBD:Ir(ppy)3 with light emitting efficiencies of 68.5 cd A?1 and 20 lm A?1 were achieved by applying a NaHCO3 interlayer.
关键词： air-stable,sodium bicarbonate,organic electronic devices,electron injection layers,baking soda,low-cost,solution-processable
更新于2025-09-04 15:30:14
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Visual servoing for low-cost SCARA robots using an RGB-D camera as the only sensor
摘要： Visual servoing with a simple, two-step hand–eye calibration for robot arms in Selective Compliance Assembly Robot Arm configuration, along with the method for simple vision-based grasp planning, is proposed. The proposed approach is designed for low-cost, vision-guided robots, where tool positioning is achieved by visual servoing using marker tracking and depth information provided by an RGB-D camera, without encoders or any other sensors. The calibration is based on identification of the dominant horizontal plane in the camera field of view, and an assumption that all robot axes are perpendicular to the identified plane. Along with the plane parameters, one rotational movement of the shoulder joint provides sufficient information for visual servoing. The grasp planning is based on bounding boxes of simple objects detected in the RGB-D image, which provide sufficient information for robot tool positioning, gripper orientation and opening width. The developed methods are experimentally tested using a real robot arm. The accuracy of the proposed approach is analysed by measuring the positioning accuracy as well as by performing grasping experiments.
关键词： Visual servoing,grasp planning,SCARA,low-cost robot arm,hand–eye calibration
更新于2025-09-04 15:30:14
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Accuracy of a Smartphone-based Autorefractor Compared with Criterion-standard Refraction
摘要： SIGNIFICANCE: Uncorrected refractive error is a prevalent problem throughout the world especially among the low-income population who have limited access to professional eye care and cannot afford eyeglasses. PURPOSE: The purpose of this study was to evaluate the accuracy and usability of a low-cost, portable, smartphone-based autorefractor (Netra, EyeNetra Inc., Somerville, MA) in adults. METHODS: A cross-sectional study was conducted to compare the portable refractor with subjective (manifest and cycloplegic) refraction for sequential adult participants with best-corrected visual acuity of 20/40 or greater. For each method of refraction, the spherical equivalent was calculated. Differences between methods were tested with linear mixed regression models. A validated usability questionnaire was administered regarding ease of use (100-point scale, higher scores better) for the portable autorefractor. RESULTS: Eighty-seven subjects (152 eyes) were studied (age range, 20 to 90 years; mean ± standard deviation, 51.9 ± 18.3 years). Mean spherical equivalent by the portable device was ?2.76 D (range, ?14.75 to 3.63 D) compared with ?2.49 D (range, ?15.25 to 4.25 D) by manifest refraction. The mean relative difference in spherical equivalent between methods was ?0.27 D (P = .001, significantly different than 0 D). The mean absolute difference between methods was 0.69 D (P < .001, significantly different than 0.5-D absolute difference). Similar results were found when comparing spherical equivalent between Netra and cycloplegic refraction methods. Subjects reported average ease of use for the Netra of 75.4 ± 19.8. CONCLUSIONS: The portable autorefractor had small but clinically significant differences from subjective refraction. The device's scores on the usability scale indicate good overall patient acceptance. The device may be valuable for use where there is limited access to a trained refractionist.
关键词： autorefractor,portable,smartphone-based,low-cost,refractive error
更新于2025-09-04 15:30:14