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[IEEE 2019 IEEE International Conference on Systems, Man and Cybernetics (SMC) - Bari, Italy (2019.10.6-2019.10.9)] 2019 IEEE International Conference on Systems, Man and Cybernetics (SMC) - Human Following of Mobile Robot With a Low-cost Laser Scanner
摘要： Human-following robots can bring a lot of convenience to our lives. The function of human-following can be decomposed into three processes: human detection, tracking and following. Considering cost and adaptability. In this paper, a low-cost laser scanner is used to achieve it. And an improved method of threshold-based clustering is proposed, which can effectively solve the problem of excessive clustering when it is far away from the laser scanner. Three types of features are extracted to recognize the legs from other objects by the random forest classifier. The position in the middle of the legs is used to indicate the position of the target person, which will be tracked by the robot using a Kalman filter algorithm and nearest neighbor algorithm. After inputting the coordinates of the followed target into the controller, the linear velocity and angular velocity of the following can be obtained. Experiments show that the robot can follow the target person stably.
关键词： Adaptive clustering,low-cost laser scanner,Human following
更新于2025-09-12 10:27:22
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[IEEE TENCON 2019 - 2019 IEEE Region 10 Conference (TENCON) - Kochi, India (2019.10.17-2019.10.20)] TENCON 2019 - 2019 IEEE Region 10 Conference (TENCON) - A low cost Human Computer Interface for Disabled People based on Eye Blink detection using Brain Signal
摘要： In the society, most of the disabled people especially completely movement impaired ones live like burdens and suffer from severe depression as they have to depend on others for day-to-day activities and cannot contribute to the community. These people may not be able to move their arms or legs but they can certainly think. If their ability to think and make decisions can be utilized in decision making situations and also if they can further be included in industrial automation structure, they will no longer be burden rather they will become man-power to the society. One of the major challenges of involving these people in such processes is making a low cost device that is affordable by the mass, made with locally available components and also interprets the person’s choice accurately. As these people are physically disable, comprehending their electroencephalogram (EEG) signal for blink detection can be an effective solution for translating their choices. EEG-based controlling devices are mobile and can serve as powerful aids for severely disabled people in their daily life. In this work, a low cost EEG sensor is made with readily available components and a framework is developed to detect voluntary eye blinks. A graphical user interface (GUI) is also developed which is suitable for the impaired person. The eye blinks of the person act as bridge between a set of choices pointed in the GUI and his/her selection interest and thus help the person control home appliances, wheel chair and even computer without depending on others.
关键词： low cost,graphical user interface,EEG,automation,blink,integrated
更新于2025-09-12 10:27:22
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Performance characteristics of the low-cost plantower PMS optical sensor
摘要： Low-cost sensors have become very popular in recent years for monitoring air pollutants. Commonly, they are calibrated by correlating their signals with reference instrument measurements and using a machine learning model to account for the influence of air properties. As particle properties vary over location, such calibration models are only relevant to measurements made at the calibration location during a limited time period. For a more general operation of these sensors it is critical that their measurement performance is established using the calibration approaches commonly for research grade instruments. Without loss the generality, here we conducted an experimental study with size-classified, composition and concentration varied particles to determine the response function of a popular low-cost sensor, Plantower PMS5003. The sensor response in all the size channels is analyzed using Tikhonov regularization and quadratic programing method with the constraints of nonnegative and monotonic response with particle size. We show that the shape of the response function is closely related to the light scattering response, consistent with what might be expected for an optical sensor. The response function shows that signals in all size channels have a complex dependence on particle material and size distribution. Accurate determination of particle mass and number distributions from the sensor signals in different channels is, thus, not straightforward. The response function calculation is validated by comparing sensor measured and predicted signals using polydispersed particles. The obtained response functions provide critical insight into the operation of a popular low-cost sensor and guidance on interpretation of its results.
关键词： light scattering response,Plantower PMS5003,quadratic programing,Tikhonov regularization,low-cost sensors,air pollutants
更新于2025-09-12 10:27:22
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Modeling and design for low‐cost multijunction solar cell via light‐trapping rear texture technique: Applied in InGaP/GaAs/InGaAs triple junction
摘要： To realize high efficiency in parallel with low cost, a light‐trapping rear texture was proposed to be implemented in substrate‐free thin‐film multijunction (MJ) cells. A detailed‐balance theory was formulated taking account of the finite light absorption in thin subcells. Such presented absorption model is general and useful to optimize the subcell thickness for MJ solar cells with light‐trapping design. It is applied for InGaP/GaAs/InGaAs triple‐junction solar cells to simulate subcell photocurrents and to obtain the current‐matching (minimum requisite) subcell thicknesses combinations. Furthermore, the detailed‐balance conversion efficiency was estimated for both radiative limit and the cases with below‐unity internal radiative efficiency. For InGaP/GaAs/InGaAs MJ cells with InGaP subcell thickness less than 600 nm, adding a random‐textured rear reflector can enhance light absorption so significantly that over 90% of InGaAs‐cell thickness and even 50% of GaAs‐cell thickness would be cut without any penalty in conversion efficiency, compared with the subcell thicknesses in traditional MJ cells with flat rear reflectors. Additionally, the thickness combination, (InGaP, GaAs, and InGaAs) = (450 nm, 333 nm, and 26 nm), is recommended to achieve both high conversion efficiency and low material cost. This work provides a very important theoretical guidance for the development on low‐cost and high‐efficiency MJ devices.
关键词： detailed‐balance limit,low cost,multijunction solar cell,texture surface,light trapping
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Nanoarchitectures as Photoanodes
摘要： Photovoltaic (PV) devices are the proficient way to obtain electrical energy from solar energy to meet the ever-increasing global energy demand. Silicon (Si)-based PV cells have reached an efficiency of 24.7% though at the cost of sophisticated technologies and expensive techniques [1], hampering low-cost production and limiting their widespread utilization [2]. Some of the drawbacks of the Si-PV devices were overcome by second-generation thin-film PV devices that are lightweight, flexible, and low-cost but are less efficient. The thin-film PV devices suffer from complex deposition process, difficulty in controlling stoichiometry and the presence of structural defects that adversely affects their performance [3]. The third-generation PV technology including organic photovoltaics (OPVs), dye-sensitized solar cells (DSSCs), quantum-dot dye-sensitized solar cells (QD-DSSCs), and perovskite solar cells have fulfilled the condition of low-cost simple fabrication process, and the research focuses is on enhancing the efficiency, performance, and stability [2]. OPVs possess low efficiency but consist of toxic materials, while perovskite solar cells suffer from moisture instability and poor reproducibility. DSSCs offer a lot of advantages such as excellent stability, low toxicity, good conversion efficiency [4], simple device design, and low-cost fabrication process that supports large-scale production [2]. Even though the highest certified conversion efficiency of DSSCs (11–13%) [4] is half of the advanced thin film or crystalline (26.4%, 27.6%, respectively), their unique functionalities make them attractive for research [5].
关键词： Dye-sensitized solar cells,Photovoltaic devices,Quantum-dot dye-sensitized solar cells,Silicon-based PV cells,Thin-film PV devices,Low-cost fabrication,Conversion efficiency,Perovskite solar cells
更新于2025-09-12 10:27:22
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Interfacial growth of the optimal BiVO4 nanoparticles onto self-assembled WO3 nanoplates for efficient photoelectrochemical water splitting
摘要： Photoelectrochemical water splitting is the most efficient green engineering approach to convert the sun light into hydrogen energy. The formation of high surface area core-shell heterojunction with enhanced light-harvesting efficiency, elevated charge separation, and transport are key parameters in achieving the ideal water splitting performance of the photoanode. Herein, we demonstrate a first green engineering interfacial growth of the BiVO4 nanoparticles onto self-assembled WO3 nanoplates forming WO3/BiVO4 core-shell heterojunction for efficient PEC water splitting performance. The three different WO3 nanostructures (nanoplates, nanobricks, and stacked nanosheets) were self-assembled on fluorine doped tin oxide glass substrates via hydrothermal route at various pH (0.8–1.2) of the solutions. In comparison to nanobricks and stacked nanosheets, WO3 nanoplates displayed considerably elevated photocurrent density. Moreover, a simple and low cost green approach of modified chemical bath deposition technique was established for the optimal decoration of a BiVO4 nanoparticles on vertically aligned WO3 nanoplates. The boosted photoelectrochemical current density of 1.7 mA cm?2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination was achieved for the WO3/BiVO4 heterojunction which can be attributed to a suitable band alignment for the efficient charge transfer from BiVO4 to WO3, increased light harvesting capability of outer BiVO4 layer, and high charge transfer efficiency of WO3 nanoplates.
关键词： Green hydrogen,Photoelectrochemical water oxidation,WO3/BiVO4 heterojunction,Low cost,Core-shell
更新于2025-09-12 10:27:22
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Achieving Fast Charge Separation and Low Nonradiative Recombination Loss by Rational Fluorination for High‐Efficiency Polymer Solar Cells
摘要： Four low-cost copolymer donors of poly(thiophene-quinoxaline) (PTQ) derivatives are demonstrated with different fluorine substitution forms to investigate the effect of fluorination forms on charge separation and voltage loss (Vloss) of the polymer solar cells (PSCs) with the PTQ derivatives as donor and a A–DA’D–A-structured molecule Y6 as acceptor. The four PTQ derivatives are PTQ7 without fluorination, PTQ8 with bifluorine substituents on its thiophene D-unit, PTQ9, and PTQ10 with monofluorine and bifluorine substituents on their quinoxaline A-unit respectively. The PTQ8- based PSC demonstrates a low power conversion efficiency (PCE) of 0.90% due to the mismatch in the highest occupied molecular orbital (HOMO) energy levels alignment between the donor and acceptor. In contrast, the devices based on PTQ9 and PTQ10 show enhanced charge-separation behavior and gradually reduced Vloss, due to the gradually reduced nonradiative recombination loss in comparison with the PTQ7-based device. As a result, the PTQ10-based PSC demonstrates an impressive PCE of 16.21% with high open-circuit voltage and large short-circuit current density simultaneously, and its Vloss is reduced to 0.549 V. The results indicate that rational fluorination of the polymer donors is a feasible method to achieve fast charge separation and low Vloss simultaneously in the PSCs.
关键词： voltage loss,nonradiative recombination,low-cost copolymer donors,fluorination,charge separation
更新于2025-09-12 10:27:22
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Long-term stable perovskite solar cells with room temperature processed metal oxide carrier transporters
摘要： A hydrophobic electron transporter is introduced to enhance the moisture stability of perovskite solar cells. The device retains 76.8% of the initial efficiency after half a year's storage. Physical vapour deposition that is compatible with flexible substrates is used to fabricate charge transporters. This scheme contributes to achieving stable perovskite devices with low time and energy inputs.
关键词： physical vapour deposition,low-cost,moisture stability,perovskite solar cells,hydrophobic electron transporter
更新于2025-09-11 14:15:04
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NRLI-UAV: Non-rigid registration of sequential raw laser scans and images for low-cost UAV LiDAR point cloud quality improvement
摘要： Accurate registration of light detection and ranging (LiDAR) point clouds and images is a prerequisite for integrating the spectral and geometrical information collected by low-cost unmanned aerial vehicle (UAV) systems. Most registration approaches take the directly georeferenced LiDAR point cloud as a rigid body, based on the assumption that the high-precision positioning and orientation system (POS) in the LiDAR system provides sufficient precision, and that the POS errors are negligible. However, due to the large errors of the low-precision POSs commonly used in the low-cost UAV LiDAR systems (ULSs), dramatic deformation may exist in the directly georeferenced ULS point cloud, resulting in non-rigid transformation between the images and the deformed ULS point cloud. As a result, registration may fail when using a rigid transformation between the images and the directly georeferenced LiDAR point clouds. To address this problem, we proposed NRLI-UAV, which is a non-rigid registration method for registration of sequential raw laser scans and images collected by low-cost UAV systems. NRLI-UAV is a two-step registration method that exploits trajectory correction and discrepancy minimization between the depths derived from structure from motion (SfM) and the raw laser scans to achieve LiDAR point cloud quality improvement. Firstly, the coarse registration procedure utilizes global navigation satellite system (GNSS) and inertial measurement unit (IMU)-aided SfM to obtain accurate image orientation and corrects the errors of the low-precision POS. Secondly, the fine registration procedure transforms the original 2D-3D registration to 3D-3D registration. This is performed by setting the oriented images as the reference, and iteratively minimizing the discrepancy between the depth maps derived from SfM and the raw laser scans, resulting in accurate registration between the images and the LiDAR point clouds. In addition, an improved LiDAR point cloud is generated in the mapping frame. Experiments were conducted with data collected by a low-cost UAV system in three challenging scenes to evaluate NRLI-UAV. The final registration errors of the images and the LiDAR point cloud are less than one pixel in image space and less than 0.13 m in object space. The LiDAR point cloud quality was also evaluated by plane fitting, and the results show that the LiDAR point cloud quality is improved by 8.8 times from 0.45 m (root-mean-square error [RMSE] of plane fitting) to 0.05 m (RMSE of plane fitting) using NRLI-UAV, demonstrating a high level of automation, robustness, and accuracy.
关键词： Low-cost,Light detection and ranging (LiDAR),Unmanned aerial vehicle (UAV),Image sequence,Non-rigid registration
更新于2025-09-11 14:15:04
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[American Society of Agricultural and Biological Engineers 2018 Detroit, Michigan July 29 - August 1, 2018 - ()] 2018 Detroit, Michigan July 29 - August 1, 2018 - <i>RPi Macro Camera: An Inexpensive and Handheld Camera Based on the Raspberry Pi Computer for Plant Phenotype Studies</i>
摘要： The technological and scientific advancement in the field of agriculture has opened a new era for design and development of modern devices for plant phenotype studies. To take advantage of recent advances in mobile technology, we built a low-cost point-and-shoot prototype camera called RPi Macro Camera, RMC, using for photographing macro images of plant. RMC consists of a Raspberry Pi computer equipped with adjustable CMOS camera modules easily to removed and replaced, as well as a lithium battery, and a 5-inch touchscreen liquid crystal display. The package size of the RMC measured about 130 x 100 x 100 mm3 and it weighed less than 600 grams. The total cost of the components was less than USD 150. The inexpensive camera, RMC, was tested on serial sections of wheat straw in different growth stages dyed with safranin O-fast green supported over microslides. Our prototype camera was direct photography with samples in conventional environment with power supplied from battery. The camera was able to obtain good-quality images for statistical analysis on red and green intensity associated with simple programming including image segmentation and color calibration. With modest improvements and further image processing algorithm, RMC is expected to be useful for a variety of plant phenotype studies
关键词： plant phenotype,color calibration,RMC (RPi Macro Camera),low cost photography,image segmentation
更新于2025-09-10 09:29:36