Wheel Rotational Speed Research Articles

Improving Freight Train Wheel Monitoring with Smart Sensors

Onboard monitoring of freight car axleboxes enhances safety, reduces maintenance costs, and improves track conditions by preventing secondary damage. Installing wireless sensors on freight cars without a nearby power source should be cost-effective, given the large quantities involved. To address this, a new wireless smart sensor node has been deployed. The sensor automatically recognizes stable operating conditions, detects wheel rotational speed from vibrations, performs real-time condition monitoring, and transmits the results to the cloud. This study outlines the smart sensor concept and the pilot field test conducted with real freight cars. The results demonstrate the ability to estimate wheel rotational speed from vibrations and the potential for detecting wheel out-of-roundness (OOR) using a newly developed condition indicator for low-power real-time operations.

Tunable diameter of electrospun fibers using empirical scaling laws of electrospinning parameters

This study introduces a new semi-empirical power-law model for predicting electrospun fiber diameter (D), addressing key processing parameters. Polycaprolactone (PCL) fibers were produced using a solvent mixture of Trichloromethane (TCM), Dimethyl Formamide (DMF), and ethanol (EtOH). Systematic experiments validated an existing theoretical model and led to the development of a novel model: D ∼ (c1/2η1/3Q1/5X2/3)/(U2/3ω1/4I1/5). This model incorporates seven crucial parameters: viscosity (η), concentration (c), voltage (U), spinning distance (X), flow–rate (Q), current (I) and collector wheel rotation speed (ω). The model was validated through a partial factorial design experiment, proving to be a valuable and reliable tool for predicting fiber diameters and optimizing electrospinning processes. The ability to control fiber diameter is essential for tailoring electrospun fibers for various applications, including biomedicine, filtration, sensors, and lightweight materials.

Hydrodynamic Flexible Spindle (HydroFlex) Polishing of turbine blade internal cooling channels for oxide removal

Internal cooling channels are essential to turbine blades for high efficiency power generation. Effective removal of aluminum oxide build-up in turbine blade cooling channels is of critical importance to refurbishment and prolonged service life of turbine blades. Conventional internal polishing processes, including abrasive flow machining, chemical polishing, and electrical discharge machining cannot effectively remove the oxide layer within the internal cooling channels due to the complex geometry with high aspect ratio and diameter variation and the electric insulation of the oxide layer. In this case study, we investigated the application of a novel hydrodynamic flexible-spindle (HydroFlex) polishing process to remove the oxide layer within the internal cooling channels of an Inconel 738 turbine blade that was taken out of serve due to oxide build-up. For a 350 mm long cooling channel featured with an inner diameter transition from ϕ4 mm to ϕ2.5 mm, within 12 min, at the grinding wheel rotational speed of 50,000 rpm and 30,000 rpm, HydroFlex was able to completely remove the 14.31 µm thick oxide layer off from the wall of the turbine blade internal cooling channel, improve the channel circularity by 54.7 %, and decrease the channel surface roughness by up to 64.3 %. The results demonstrated the effectiveness of HydroFlex in polishing complex internal cooling channels of turbine blades for oxide removal and potential blade service life extension.

Experimental study on decarburization of fine fly ash by electric separation

ABSTRACT The effect of rotary triboelectric separation parameters on decarburization of fly ash was systematically studied to prove that the technology was an effective means to purify fly ash. The results showed that obvious mismatch of carbon particles occurs when separation voltage was greater than 25 kV, while mismatch of other mineral particles was generated when separation voltage was greater than 30kV; The decarburization effect of fly ash could be significantly reduced due to the decrease of particle surface charge density when the feed frequency was greater than 20 hz. The feed was also affected by the speed and direction of the particle feed, the closer to the middle of the feed port, the higher the probability of the particle being effectively separated; when rotation speed of the friction wheel exceeded 4000 r/min, the particle mismatch in the separation chamber becomes more and more obvious. In addition, the speed of the friction wheel also affected flow field in separation chamber, which may have an adverse effect on separation effect; Co-flow velocity affected retention time of particles in the separation chamber. 6 m/s is the best co-flow velocity for fly ash decarburization. In this case, the flow field generated by the co-flow is uniform to ensure stable transport of particles.

Development and experimental performance evaluation of a small-scale aquavoltaic system for microalgae production

The primary objective of this study is to develop a small aquavoltaic system and evaluate key parameters, including dissolved oxygen (DO), pH, water temperature and dead zones in an open raceway pond to improve the conditions for the production of microalgae while generating electricity. The key variable parameters examined were the rotation speed of a paddle wheel at 10, 20 and 30 rpm, water depth at 15, 25 and 35 cm and response time at 0.5, 1 and 1.5 h were evaluated during May 9–15, 2023. Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to optimize these parameters for acheiving DO levels suitable for microalgae production. The findings showed that increasing the rotation speed of a paddlewheel at the appropriate water depth significantly influences the flow rate, thereby controling DO levels. A maximum DO value of 6.94 mg/l was achieved after 1 h at a water depth of 25 cm and the paddle wheel rotation speed of 20 rpm. Increasing the rotation speed from 10 to 30 rpm resulted in DO values within the optimal range of 6–7 mg/l, reducing dead zones from 21.05 % to 9.16 %. However, with a paddle wheel spinning at 10 rpm, DO decreased below 5 mg/l with increasing water depth and minimal shading, with pH reaching a minimum of 6.8 ppm. Addiotionally, the experiments revealed no significant difference in efficiency between modules installed in open ponds and those installed on the ground over short time periods. The economic analysis indicated that spirulina production costs are 7 % higher with the non-aquavoltaic system due to non-solar electricity use. Furtehrmore, the cost of spirulina produced with the aquavoltaic system was 0.4975 USD/g at a 5 % interest rate and 0.331 USD/g at a 10 % interest rate in the fifth year. The current study underlines that aquavoltaics could have the potential to further increase the production of microalgae and thus reduce production costs. This opens up opportunities for long-term research leading to further optimization between energy production and environmental sustainability in aquaculture systems.

Analysis of Maize Planting Mode and Simulation and Optimization of Ridging and Fertilization Components in Arid Area of Northwest China

The arid area of Northwest China belongs to the rain-fed agricultural area of the Loess Plateau, and water resources have become one of the important factors limiting agricultural development in this area. This study employed the AquaCrop model to predict the yield advantages and environmental adaptability of maize in Dingxi City from 2016 to 2020 under two cultivation practices: ridge tillage (100% film coverage with double ridge-furrow planting) and flat planting (81.8% film coverage with wide-film planting). The numerical simulation of the tillage and fertilization process of the double-ridge seedbed was carried out by EDEM, and the key components were tested by the Box–Behnken center combination test design principle to obtain the optimal parameter combination. The results showed that ridge planting was more suitable for agricultural planting in rain-fed arid areas in Northwest China. The simulation analysis of ridging and fertilization showed that the forward speed of the combined machine was 0.50 m/s, the rotation speed of the trough wheel of the fertilizer discharger was 39 rmp, and the rotary tillage depth was 150 mm. The qualified rate of seedbed tillage was 93.6%, and the qualified rate of fertilization was 92.1%. The research shows that the whole-film double ridge-furrow sowing technology of maize is more suitable for the rain-fed agricultural area in the arid area of Northwest China. The simulation results of the ridging fertilization device are consistent with the field experiment results. The research results provide a certain technical reference for the optimization of the whole-film double ridge-furrow sowing technology.

Quantitative Detection of Vertical Track Irregularities under Non-Stationary Conditions with Variable Vehicle Speed.

Track irregularities directly affect the quality and safety of railway vehicle operations. Quantitative detection and real-time monitoring of track irregularities are of great importance. However, due to the frequent variable vehicle speed, vehicle operation is a typical non-stationary process. The traditional signal analysis methods are unsuitable for non-stationary processes, making the quantitative detection of the wavelength and amplitude of track irregularities difficult. To solve the above problems, this paper proposes a quantitative detection method of track irregularities under non-stationary conditions with variable vehicle speed by order tracking analysis for the first time. Firstly, a simplified wheel-rail dynamic model is established to derive the quantitative relationship between the axle-box vertical vibration and the track vertical irregularities. Secondly, the Simpson double integration method is proposed to calculate the axle-box vertical displacement based on the axle-box vertical acceleration, and the process error is optimized. Thirdly, based on the order tracking analysis theory, the angular domain resampling is performed on the axle-box vertical displacement time-domain signal in combination with the wheel rotation speed signals, and the quantitative detection of the track irregularities is achieved. Finally, the proposed method is validated based on simulation and field test analysis cases. We provide theoretical support and method reference for the quantitative detection method of track irregularities.

Investigation on the Deformation and Surface Quality of a Bearing Outer Ring during Grinding Processing.

Thin-walled bearings are widely used owing to the advantages of their light structure, high hardness, and strong load-carrying capacity. However, thin-walled bearings are often prone to deformation during the machining process, which can seriously affect the performance of the bearings. In addition, the machining deformation and quality of bearings are difficult to balance. To address the above issues, this paper investigates the effects of the machining parameters on the machining deformation, surface quality, and machining efficiency of a thin-walled bearing during the roughing stage. The dynamic balance between deformation inhibition and high quality in rough grinding was studied, and the optimal parameters for thin-walled bearing outer ring grinding were obtained. The deformation mechanism of thin-walled bearings caused by grinding was revealed through simulation and experimental analysis. The results show that the machining deformation and quality reach a balance when the workpiece speed is 55 r/min, the grinding wheel rotational speed is 2000 r/min, and the feed rate is 0.1 mm/min. Deformation increases with the increase in workpiece speed and grinding wheel speed. At the same time, the surface roughness increases with the increase in the workpiece speed, but the increase in the wheel speed will improve the surface roughness. As the workpiece speed increases, the surface topography shows a more pronounced stockpile of material, which is ameliorated by an increase in grinding wheel speed. As the rotational speed of the workpiece increases, the number of abrasive grains involved in the process per unit of time decreases, and the surface removal of the workpiece is less effective, while the increase in the rotational speed of the grinding wheel has the opposite effect. The grinding deformation of thin-walled bearings is mainly induced by machining heat and stress. As the rotational speed increases, the heat flux in the grinding zone increases. More heat flux flows into the surface of the workpiece, causing an increase in thermal stresses on the inner surface of the bearing collar, leading to greater deformation. The temperature in the grinding area can be reduced during machining, realizing a reduction in deformation. The research content contributes to the balance between high quality and low distortion in machining processes.

Optimum Control Wind Power Installations Being Subjected to Ice Formation on Wind Wheel Blades Within Wind Electrc Station Structure

On the basis of the analysis of wind electric unit control with preliminary installation of blades at a required angle according to an estimation of the drive pitch engine start timesubjected toice formation on wind wheel blades to minimize the wind turbine rotor angular speedtransient time, that promotes wind wheel rotation speed stability under the conditions of incomplete wind speed and the electric loadinginformation, that may change significantly with time, the criterion of access time to the of bladeposition control devicefrom the proposed and basic methods of control is established. The program module towind power automation control within thewind electric stationstructure is developed, providing relevantsystem preparation for external actions due to ice formation on blades wind wheel at different operation modes of power unit,that showedangular speed increase of a wind turbine rotor during winter time thus demanding more energy of a wind stream (14m/s) in comparison with the spring and autumn period (11.1m/s).Therefore, ice formation on wind wheel blades slows down wind wheel rotor rotation. Hence, the offered control method efficiency during winter time to avoid control delay is shown byrotation speed increase of a wind turbine rotor towards can be realizedforwind speeds exceeding 13m/s. The improved software control unit of wind power installation within the structure of wind power station based on the power unit operation modes provides: «Summer mode» - electric power generationunder favorable environment conditions; «Winter mode» - electric power generation under ice formation on blades wind wheel.

Identifying some regularities of the aerodynamics around wind turbines with a vertical axis of rotation

The design of wind turbines with a vertical axis of rotation is quite simple, which successfully increases the level of efficiency. Existing vane wind turbines have a shortage of currents in the form of negative torque, and installations operating on the Magnus effect have a low lifting force. In this regard, the development and research of installations operating at speeds from 3 m/s, with combined blades with increased work efficiency is an urgent topic. The object of the study is a wind turbine consisting of a system of rotating cylinders and fixed blades operating at low air flow speeds starting from 3 m/s. Numerical studies were carried out using the Ansys Fluent program and the implemented k-ε turbulence model. A special feature of the work is the combined use of two lifting forces: a cylinder and fixed blades, which made it possible to increase the output aerodynamic parameters. Calculations were performed for incoming flow rates of 3 m/s, 9 m/s, 15 m/s and cylinder rotation speeds of 315 rpm, 550 rpm, 720 rpm. It is determined that the period of change of the moment of forces T is 0.5 m/s, which corresponds to 2 revolutions of the wind wheel per minute. It was found that the cylinder rotation frequency in the range from 315 rpm to 720 rpm does not affect the period of change in the moment of forces, but the amplitude of the moment of forces increases with decreasing rotation frequency. The dependences of the rotation speed of the wind wheel on the velocity of the incoming flow, found by the method of sliding grids and 6DOF, are also obtained. It is determined that the installation begins to make revolutions from 3 m/s, with a positive torque of forces. The field of practical application of the numerical results will be useful for further research of wind turbines with combined blades

New application of ionic liquid as a green-efficient lubricant

In the present work, it has been attempted to use ionic liquid as a green and compatible additive to base cutting fluid for the grinding process. Grinding forces in tangential and normal directions and the surface quality of the Inconel 718 superalloy were determined as a criterion for comparing the results, and the cutting parameters, such as the wheel rotation speed, workpiece speed, and cutting depth, were also selected as variable parameters in three levels. The experimental results showed that, in addition to the compatibility issue of the ionic liquids, the normal force in the case of ionic-liquid and mineral-based lubricants was declined by approximately 49.3 % than that of non-used cutting fluid technique. By increasing cutting depth from 20 to 60 μm, workpiece speed from 1000 to 3000 mm/min, and wheel speed from 10 to 30 m/s led to an increase of 168 % and 139 %, 46 % and 38 %, and 167 % and 78 % in normal and tangential forces, respectively. The results showed that the grinding forces reduced and the surface integrity of the workpiece improved when using ionic liquid as an additive compared to the mineral-based one. The reason of this superiority can be attributed to the more tendency of liquid molecules to adhere to the surface of the superalloy and form a strong lubricant layer with a lower static contact angle, compared to the mineral-based fluid, which leads to the creation of stable lubrication conditions in the high-stress grinding affected zone. The static contact angle of the DI water was approximately 62 °, while by changing the droplet type to mineral-based fluid and ionic liquid, the CA value was diminished to 51 ° and 38 °, respectively, with reducing rate of 18 %, and 39 %. In addition to experimental study, mathematical models were also developed to predict the grinding forces and surface roughness by means of response surface methodology (RSM). The result of analysis of variance (ANOVA) showed that the fitted models have high accuracy compared to the experimental results.

Optimal design and experimental research on the spiral groove wheel fertilizer apparatus

As the "core" of fertilizer machinery, the fertilizer apparatus has a significant impact on the effect of fertilization operation. At present, the straight-grooves type external groove wheel fertilizer apparatus is widely used, which has the problem that the fertilizer flow fluctuates periodically and is not conducive to precision fertilization. Therefore a kind of the spiral groove wheel fertilizer apparatus is proposed in the paper, and the designed fertilizer apparatus is experimented and optimized by using Design-Expert Software 10 and a self-made fertilizer experiment bench. Taking the fertilization amount and the variation coefficient of fertilization amount as the experiment index, the interaction effects of the groove radius, spiral rising angle, groove wheel rotation speed, and fertilizer tongue inclination of the spiral groove wheel type fertilizer wheel on the fertilization performance are analyzed. The quadratic regression models of multiple factors of the fertilization amount and the variation coefficient of fertilization amount are established. Through optimization and experiment validation, the optimal combination of parameters is determined as follows: the groove radius is 13.5 mm, the spiral rising angle is 62°, the groove wheel rotation speed is 29.4 r/min, the fertilizer tongue inclination is 5°, the fertilization amount is 17.810 g and the variation coefficient of fertilization amount is 5.60%.

Effects of the wheel rotation speed during the melt-spinning process on the structural morphology and the thermoelectric properties of Ti0.5Zr0.5NiSn alloy

Half-Heusler alloys based on (Ti, Hf, Zr)NiSn possess excellent mechanical and chemical properties as well as high thermal stability, making them promising materials for high-performance thermoelectric (TE) power generators. However, the high cost of Hf limits its use in these alloys. Therefore, Hf-free (Ti, Zr)NiSn alloys synthesised using a rapid process offer a cost-effective approach to reducing product costs. In this study, we employed the fast synthesis melt-spinning (MS) method to prepare an Hf-free Ti0.5Zr0.5NiSn alloy while systematically optimising MS conditions. We found that by varying the rotation speed of the copper wheel in the MS system from 1000 to 4000 rpm, a marked change in the structural morphology of the melt-spun ribbons occurred. Grain growth during the spark plasma sintering process significantly affected TE properties of the bulk Ti0.5Zr0.5NiSn alloy depending on the structural morphology. As a result, a maximum ZT of ~1.1 at 823 K was achieved for a wheel rotation speed of 3000 rpm, which is comparable to ZT values obtained from the (Ti, Hf, Zr)NiSn-based half-Heusler alloys prepared by other methods.

Experimental investigation on the mechanical properties of resistance seam welding of thin sheet

In the presents research an experimental investigation was conducted on the resistance seam welding of thin sheets of thickness 0.2 mm for packaging application. The most difficult issues in such sectors are reducing product weight without compromising weld strength. The machines used in such industries are of certain specifications. Major modifications in the machine are very costly. Thus, the industrial need is to regulate the machine in the given specification for better productivity and high quality of the product. Twenty sets of experiments were conducted on the industrial grade resistance seam welding machine in order to investigate the versatility of the machine and possible effect on the mechanical and microstructural properties of the resistance seam welded joint. The experiments were conducted in two parts. In the first part only current was varied (i.e. single factor experiment) keeping other parameters such as electrode wheel speed and welding voltage unchanged. In the second set of experiments, both current and electrode wheel speed were changed keeping voltage constant. Mechanical properties such as tensile strength, yield strength, breaking load, elongation at breaking were studied as the function of current and wheel rotational speed. The yield strength firstly increases up to 84 A and then decreases with increase in the welding current keeping other parameters fixed. The elongation at break also decreases with increasing current value. Microstructural properties were also analysed for the proper understanding of the process and potential effect on the various mechanical properties.

Theoretical analysis and experiment of seed-picking mechanism of belt high-speed seed-guiding device for corn

Under the condition of high-speed sowing (12-16 km/h), due to the high rotational speeds of the seed disk, the seeds leave the disk at an excessively high speed, which challenges the seed-picking capacity of the belt-type high-speed seed guide device. In this paper, the theory of seed-picking mech-anism is analyzed, and performance optimization tests are completed to further improve the operation effect of the seeder. The mechanical model of seed picking was established through the force analysis of seeds. The influence of vacuum degree, feeder wheel rotation speed, and seed picking angle on seed picking quality and the parameter range of each factor were obtained by single factor test. A three-factor five-level quadratic orthogonal rotation combination test was performed, and the test re-sults were refined and evaluated. The test factors used were vacuum degree, feeder wheel rotation speed, and seed picking angle. The test indexes used were the seed picking rate, re- picking rate, and miss- picking rate. According to the results, the seed picking rate was 99.89%, the re-picking rate was 0, and the miss-picking rate was 0.11% when the vacuum degree was 6.89KPa, the feeder wheel rota-tion speed was 568.95rpm, and the seed picking angle was 7.6°.

Experimental Investigation of the Calcified Plaque Material Removal Rate in Coronary Rotational Atherectomy

Abstract Rotational atherectomy (RA) is a minimally invasive procedure to remove the calcified atherosclerotic plaque from arteries to restore blood flow. It uses a high-speed, metal-bonded diamond abrasive grinding wheel to pulverize the calcified plaque into absorbable debris via a catheter through the artery. Although RA has been clinically used for over two decades, procedural complications persist and there remains a lack of consensus on the optimal device parameters. This study aims to investigate the material removal rate (MRR) in coronary RA with respect to grinding wheel sizes and rotational speeds based on a tissue-mimicking phantom. Three grinding wheel sizes, 1.25, 1.5, and 1.75 mm in diameter, and three rotational speeds, 1,20,000, 1,50,000, and 1,80,000 rpm, were investigated. The RA MRR was presented as the luminal area gain and measured by microscopy and image processing. The results show the increase in the grinding wheel size or rotational speed leads to a higher MRR and luminal gain in RA. With a 1.75 mm diameter grinding wheel rotating at 1,80,000 rpm in a 2 mm initial diameter lumen, the max MRR and the luminal gain are 2.49 mm2/three passes and 5.09 mm2, respectively. The MRR decreases as the number of grinding passes increases during RA with the same grinding wheel rotating at a constant speed. This study provides a thorough understanding of the wheel size and speed effects on coronary RA MRR for potential improvements in RA devices and clinical operational guidelines.

Experimental evaluation of metal–organic framework desiccant wheel combined with heat pump

Reducing the consumption of high-grade energy on the regeneration side is crucial to decreasing the energy consumption of the desiccant wheel system. Metal-organic framework desiccants exhibit superior moisture absorption performance. However, there has been no research on the application of metal–organic framework materials in desiccant wheel systems for low-grade heat source regeneration. To address this research gap, this study applied a composite adsorbent of the metal–organic framework in a heat pump-desiccant wheel system and experimentally evaluated the performance of the heat pump-metal–organic framework desiccant wheel system using low-grade heat sources under different operating conditions. A comparison was made with electrically heated desiccant wheel systems and heat pump-desiccant wheel systems using traditional silica gel adsorbents. The results showed that the optimal desiccant wheel rotational speed was 8.63 r·h−1, and the optimal airflow was 300 m3·h−1. The energy consumption of the heat pump-metal–organic framework desiccant wheel system was only 42.77% of that of the electrically heated desiccant wheel system, and its dehumidification energy factor was 2.07, which is higher than that of the heat pump-silica gel desiccant wheel system. This demonstrates the feasibility and efficiency of utilizing low-grade heat sources for regeneration using metal–organic framework desiccants in practical applications.

Design of a Large-Format Low-Light Imaging System Based on the RGB Filter Wheel

In order to capture true-color information of distant targets under extremely low light, a large-format low-light imaging system is designed based on an RGB filter wheel. By decomposing the system indicators, this study proposes a method for acquiring low-light true-color images using a large-aperture, low-distortion optical lens combined with an RGB filter wheel capable of multi-line sequential exposure. The optical field segmentation is achieved using a four-panel optical reflective prism, and the images from four high-sensitivity SCOMS detectors are stitched together to form a composite image. The working principle of the system is explained, and the low-light imaging capability is thoroughly evaluated. The dimensions and rotation speed of the filter wheel are then calculated in detail, ensuring accurate synchronization of the filter wheel’s speed and exposure time. The calculation method for the parameters of the four-panel reflective prism structure is investigated, mathematical expressions for the geometric parameters of the prism assembly are provided, and a prism assembly suitable for four-way spectral separation is designed. Based on the research and design results, a large-swath-width, low-light true-color imaging system is developed that is suitable for an environmental illuminance of 0.01 lux. The system achieves a ground pixel resolution of 0.5 m (at an altitude of 5 km) and an effective image resolution of 4 K × 4 K, and is capable of accurately reproducing target color information. Laboratory and field flight tests verified that the large-swath-width images obtained by the imaging system are clear, with high contrast and resolution. After image fusion and spectral registration, the color images exhibit full saturation and high fidelity, meeting the requirements of low-light true-color imaging under airborne conditions. The design methodology of this low-light imaging system can serve as a reference for the development of airborne low-light imaging equipment.

Experimental and Modeling Study of Abrasive Wear of Tungsten Carbide Drilling Bit in Wet and Dry Conditions

The results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by using ANSYS12.1 program for dry and wet abrasive wear rates. The general trend for all the results of wet tests is that an increase in the applied load as well as wheel rotational speed produces an increase in wear rate, while at the dry tests the behavior shows an increase and fluctuating in wear rate due to the transition in wear mechanism. As compared to the dry tests, the volume losses in wet tests have much higher values, that is because the presence of water which causes high adhesion between sand particles and specimen surface as well as wear-corrosion interaction which accelerate the wear rates. The percentage errors between theoretical and experimental results are more stable with the wet than dry tests due to the stability in wear rates.

Evaluation method of rowing performance and its optimization for UAV-based shot seeding device on rice sowing

In recent years, unmanned aerial vehicle (UAV) has been widely used in the agricultural production. Combined with the promotion of rice direct seeding technology, UAV rice seeding has become an important planting method. In order to quickly obtain the rowing performance on rice sowing, this study proposes an evaluation method based on image recognition technology. In the process of image recognition, a binary method of dynamic threshold based on mean filter difference (BD-MFD) was adopted, and obtained the position coordinates of the seeds. According to the evaluation method, the key structural parameters and operational parameters of the UAV-based shot seeding device are optimized. In the bench test, the size parameters of guide tube were optimized, and the best seeding effect was obtained when the length and diameter of the guide tube were 100 mm and 17 mm, respectively. Experiments were carried out on the seeding effect under different seed discharge rate levels, and the reasonable range of the seed metering wheel rotational speed was 16–24 rpm. In the field seeding test, the appropriate friction wheel rotation speed at different working heights was obtained. In the two-factor comprehensive test of flying speed and seed metering wheel rotational speed, when the flying speed was 1.0–2.0 m/s and the seed metering rotational wheel speed was 22–26 rpm, it has better seeding uniformity. In the five-row seeding experiment, the average width of seed row (Bd) ranged from 66.17 mm to 75.34 mm, and the C.V. (coefficient of variation) of seeding uniformity was between 18.44 % and 27.04 %. The study provided a new idea for UAV rice seeding, and optimized the structural parameters and operation parameters through experiments.