Motion Energy Research Articles

The Mystery and Clarity of Leonardo da Vinci's Coefficient of Friction

The science of friction has been using the coefficient of friction as the main quantitative characteristic of the friction process for more than five centuries. The concept of the coefficient of friction as a characteristic of the resistance to the movement of rubbing surfaces in a hidden form was formulated by Leonardo da Vinci: "Each rubbing body exerts a friction resistance equal to one quarter of its weight, provided that the flat plane is in contact with the polished surface". Two centuries later, the coefficient of friction appeared explicitly, in the form of a formula, in the works of G. Amontons. It is clear that the coefficient of friction is a convenient friction parameter, easily determined in the experiment. However, what is the physical meaning of resistance to the movement of rubbing surfaces? Modern engineering believes that the coefficient of friction has no physical meaning. Thermodynamic analysis of the friction process is performed. The evolutionary patterns of the behavior of the friction contact are shown. A structural-energy interpretation of the logic of the coefficient of friction (resistance) is proposed: accumulation of potential energy of defects in the crystal structure of the deformable volume by friction contact. The static potential energy of the formed defects in the crystal structure of the contact is a measure of the decrease in the kinetic energy of the relative motion of the rubbing surfaces. Such a formulation of resistance to movement under friction has a deep physical and clear meaning for a scientist and engineer. The substantiation of Leonardo da Vinci's formulation of friction that the friction resistance should be equal to 0.25 is given. The interpretation of this rule is given for the case of friction in mechanisms (machines).

Rectilinear car motions taking into account the elasticity and deformability of tires

In this paper, the problem of developing a mathematical model of rectilinear motion of a car is solved, taking into account the elasticity and deformability of tires, as well as, for the same radii of the wheels of the car, and taking into account plane-parallel motion at a constant speed. The kinetic energy of the rectilinear motion of the car is found in the case of the same rotation of the front wheels around the axis of the pivots. Generalized forces are taken as sum of forces acting on the system and forces due to the deformation of the pneumatics. The forces acting on the system are found by virtual work method. The forces due to the deformation of the pneumatics are found as the generalized forces acting on the system under consideration, in the calculation of which all forces are taken into account, except for the tire deformation forces associated with angles and displacements. Using these kinetic energies and generalized force expressions, Lagrange's equations of the second type were used to obtain the differential equations of the rectilinear motion of the car. From the resulting mathematical model, it is possible to check and analyze the dynamics and stabilities of the system in various specific cases, i.e., under the influence of non-potential forces in the tire materials, and at large values of the tire kinematic parameters, and at high speed movements of the car. As a result of determining the stability field and stability borders at different values of constructive parameters, it will be possible to find the optimal parameters of the system and study its dynamics.

Solid state 1H, 7Li, and 13C NMR studies on new ionic plastic crystals of crown ether-Li-TFSA complexes.

This study provides the first evidence that a Li ion can form ionic plastic crystals using crown ether with a bis-(trifluoromethanesulphonyl) amide (TFSA) anion. 1H, 7Li, and 13C nuclear-magnetic-resonance (NMR) measurements of the 15-crown-5-Li-TFSA complex revealed that the constituents underwent isotropic reorientation in the plastic crystalline phase. The NMR data of the 12-crown-4-Li-TFSA salt showed that the complex is a rotator crystal (the complexes are denoted as [Li 15C5] and [Li 12C4] in this paper). The X-ray diffraction (XRD) reflection patterns of the [Li 15C5] crystal recorded in the highest-temperature solid phase (plastic phase) could be indexed to a cubic structure. Conversely, [Li 12C4] could be fitted to a trigonal structure. In this study, [M (3n)Cn] (M = Li, Na, K; n = 4-6) complexes were also prepared, and NMR, DSC, XRD, and electrical conductivity measurements were performed. Based on these results, we additionally revealed that the [Na 15C5] and [K (15C5)2] complexes are also new rotator crystals. Single-crystal XRD measurements also revealed that the [Na 15C5] compound has two stable sites in the crystal. Activation energies of molecular motions in the [M (3n)Cn] crystals were estimated using 1H NMR relaxation time (T1 and T2) measurements. The electrical conductivity measurements of [Li 12C4], [Li 15C5], and [Na 15C5] showed high ionic conductivities (∼10-2 S cm-1).

An Efficient Method for Underwater Video Summarization and Object Detection Using YoLoV3

Currently, worldwide industries and communities are concerned with building, expanding, and exploring the assets and resources found in the oceans and seas. More precisely, to analyze a stock, archaeology, and surveillance, several cameras are installed underseas to collect videos. However, on the other hand, these large size videos require a lot of time and memory for their processing to extract relevant information. Hence, to automate this manual procedure of video assessment, an accurate and efficient automated system is a greater necessity. From this perspective, we intend to present a complete framework solution for the task of video summarization and object detection in underwater videos. We employed a perceived motion energy (PME) method to first extract the keyframes followed by an object detection model approach namely YoloV3 to perform object detection in underwater videos. The issues of blurriness and low contrast in underwater images are also taken into account in the presented approach by applying the image enhancement method. Furthermore, the suggested framework of underwater video summarization and object detection has been evaluated on a publicly available brackish dataset. It is observed that the proposed framework shows good performance and hence ultimately assists several marine researchers or scientists related to the field of underwater archaeology, stock assessment, and surveillance.

A PET/Graphite‐Based Triboelectric Nanogenerator for Monitoring the Health of Leg Muscles in Football

Recently, self‐powered flexible sensors have shown important application value in sports training. Thus, we design a triboelectric nanogenerator based on PET/Graphite composite film (PG‐TENG) to harvest human motion energy and monitor football player leg muscle health. The polytetrafluoroethylene (PTFE) film and PET/graphite composite film serve as the triboelectric pairs; meanwhile, the PET/Graphite composite film also plays the role of conductive electrode. Moreover, the PET/graphite composite film can be prepared by a simple reverse molding process. According to the results, the instantaneous power density of PG‐TENG can arrive at 5.94 mW/m2 at 130 MΩ. The PG‐TENG can serve as the motion player to monitor the health of football players’ leg muscles and various football sports postures, including the posture of bouncing and dribbling. This research will promote the application of self‐driving sensors in sports monitoring.

Fractal structured charge-excitation triboelectric nanogenerators for powering portable electronic devices.

Effective power management on the outputs of triboelectric nanogenerators (TENGs) is critical for their practical applications due to the large impedance and unbalanced load matching. Recently proposed voltage multiplying circuits for external-charge excitation and self-charge excitation are usually unstable and require reversal for device restarting and common switched-capacitor-converters usually cause large switching losses. In this work, we fabricated a fractal structured charge-excitation circuit for TENGs using diodes and capacitors. The fractal switched-capacitor-converter coupled with voltage regulator diodes can greatly boost the output charge and current of the TENG without reverse starting. The managed output performance of the TENG can be controlled by the electronic component parameters and external operating frequency. Through the component and condition optimization, the fractal structured charge-excitation TENG (FSC-TENG) can achieve nearly 5.8 times charge boosting and almost 16.8 times power boosting in the pulsed mode. Furthermore, the FSC-TENG successfully drove a hygrothermograph and was integrated into a yoga mat for harvesting human-body motion energy to power an electronic watch and a pedometer. The FSC-TENG with good charge accumulation properties and stability is a promising candidate for practical self-powered applications.

Результаты кинетостатического исследования дорожной энергетической установки с ползунно-коромысловым преобразователем

The base factor of accidents with pedestrians is zero visibility as revealed by Russian auto statistic. Drivers have a poor view of pedestrians and crosswalk at twilight and night against road sign. Currently autonomous wind turbines and solar panels are used for improve of road safety. From another angle practice possibility of equipment type as road energy harvesting system is studying scientific collaboration. Operation of the systems is based on car motion energy conversion to electrical energy. The research goal is force determination acting in mechanism of road energy harvesting system. As a result of force study of road energy harvesting system, the forces in mechanical energy converter to electrical energy are determined when a car pass. On generator shaft torque is created equal 393 N∙m when typical car passes with 1600 kg mass by way road energy harvesting system from the performed calculations. Moreover, in generator resistive torque produces with value depending speed of moving car: at speed of 20 km/h the resistive torque is 115 N∙m; at speed of 30 km/h resistive torque is 260 N∙m; at speed of 40 km/h resistive torque is 390 N∙m. The energy amount saved by flywheel is directly proportional to speed and has values: at speed of 20 km/h energy is 47 J; at speed of 30 km/h energy is 105 J; at speed of 40 km/h energy is 165 J. The calculation data show that road energy harvesting system is operable with given parameters of construction elements.

Preparation of a high-performance chitosan-based triboelectric nanogenerator by regulating the surface microstructure and dielectric constant

High-performance chitosan-based triboelectric nanogenerator was prepared by film casting method for collecting human motion energy.

Acid and alkali-resistant fabric-based triboelectric nanogenerator for self-powered intelligent monitoring of protective clothing in highly corrosive environments.

The corrosion of materials severely limits the application scenarios of triboelectric nanogenerators (TENGs), especially in laboratories, chemical plants and other fields where leakage of chemically corrosive solutions is common. Here, we demonstrate a chemical-resistant triboelectric nanogenerator (CR-TENG) based on polysulfonamide (PSA) and polytetrafluoroethylene (PTFE) non-woven fabrics. The CR-TENG can stably harvest biological motion energy and perform intelligent safety protection monitoring in a strong corrosive environment. After treatment with strong acid and alkali solution for 7 days, the fabric morphology, diameter, tensile properties and output of CR-TENG are not affected, showing high reliability. CR-TENG integrated into protective equipment can detect the working status of protective equipment in real time, monitor whether it is damaged, and provide protection for wearers working in high-risk situations. In addition, the nonwoven-based CR-TENG has better wearing comfort and is promising for self-powered sensing in harsh environments.

Совершенствование методики расчета скорости движения транспортного средства по полученным деформациям при контакте с объектом малой массы при дорожно-транспортном происшествии

One of the promising directions of road traffic accident examination related to the calculating of vehicle’s driving speed is the speed calculation based on the efforts of motional energy for the deformation of vehicle bodies. The currently used technique of calculating vehicles’ road speed based on the vehicle`s deformations is considered. There is substantiated lack of possibility for applying this technique in the absence of traces of objects` movement in case of a collision with a small-sized object with a mass much less than the mass of the vehicle. The authors offer using the Galileo's principle of relativity when looking for the solution of this problem. The proposed solution was tested on the example of a real road traffic accident.

Experimental Analysis of Pneumatic Motion Control Application with Piezo Technology

Piezo technology is used in a large number of sectors thanks to the possibility of switching between electrical energy and motion energy. In particular, Piezo technology provides an important advantage in pneumatic applications with its features such as low energy consumption, accuracy, quiet operation, compact structure, fast switching possibility, quiet operation and lightness. Directional control, proportional pressure control, proportional flow control, positioning, soft-stop and similar basic applications are being transformed into controlled and digitalized Pneumatic System applications. In this paper, piezovalves developed using piezoceramic material are compared with solenoid valves in pneumatic applications. The working methods and advantages of piezo technology in pneumatic applications such as pressure control, flow control, motion control are presented. The experimental test device with a pneumatic cylinder working with piezo valves and position sensors was installed and motion control application was performed. In the experimental results of the application, the system characteristics can be observed graphically and the results can be analyzed.

Planning and analysis of safety-optimal lunar sun-synchronous spatiotemporal routes

Lunar sun-synchronous roving is an affordable and promising manner of acquiring continuous power supply and warmth in robotic polar exploration. Sun-synchronous route planning is challenging to meet the spatiotemporal constraints of lunar topography and time-varying illumination. Moreover, in pursuit of spaceflight feasibility and safety, the safety-optimal planning method adapting to spatiotemporal maps remains to be addressed. This paper takes the first step to investigate this issue, in which the distribution of roving speed is considered a critical factor. Three-dimensional lunar spatiotemporal maps are constructed based on topography and illumination analysis. A spatiotemporal planning algorithm named MSST-A* is proposed, which takes a multi-speed node expansion mechanism, thus supporting speed distribution optimization. Afterward, route evaluation functions involving motion, energy, and integrated risk, together with the optimal heuristic function, are designed for safety-optimal planning. Two comparative tests are conducted, and results indicate that the proposed approach is practical and superior in terms of motion safety and energy reliability. Besides, an integrated-risk-minimal route circumnavigating the Shackleton Crater at the south pole in three lunar days is solved, demonstrating the existence of long-term lunar sun-synchronous routes with good engineering significance.

NIR light-induced rapid self-healing hydrogel toward multifunctional applications in sensing

Flexible conductive hydrogels with self-healing ability have attracted great attention in the fields of wearable devices and healthcare monitoring due to their recoverability and sustainability. Herein, the application of inorganic antimony sulfide (Sb2S3) as photothermal agent is extended to the field of self-healing hydrogel for the first time. A near-infrared (NIR) light-induced rapid self-healing double-network conductive hydrogel (SPOH gel) via on-demand irradiation was fabricated by incorporating dopamine (DA)-modified polypyrrole (PPy) coated Sb2S3 nanorod (Sb2S3 @PPy-DA) into the polymer matrix of polyvinyl alcohol (PVA)/poly(N-(2-hydroxyethyl)acrylamide) (pHEAA) in a water-glycerol dispersion medium. The SPOH gel with adhesive and anti-freezing properties exhibited robust tensile strength (1.25 MPa), large elongation (620%), high interfacial toughness (251 J/m2), and outstanding sensitivity (GF = 4.97). The incorporation of Sb2S3 @PPy-DA for SPOH gel endowed high conductivity (2.26 S/m) and promoted rapid self-healing process under NIR light irradiation (within 90 s). Moreover, SPOH gel could be widely applied to various applications, including monitoring various human motions as strain sensor, detecting electrocardiogram signals as biopotential electrodes, and harvesting energy as self-powered device. The multifunctional SPOH gel with the integrated attractive capabilities of rapid self-reparability and real-time physiological signal detection, providing a promising route to develop wearable smart devices in motion monitoring, healthcare management, and energy harvesting applications.

Motion energy perspective of tracked locomotion system of autonomous tractor-trailer robot

In realm of researches involved in autonomous tractor-trailer robot, novel purpose of this applied research has been dedicated to motion energy perspective of tracked locomotion system of the robot. Hence, motion energy indicators including motion energy consumption, motion energy dissipation, and drawbar pull energy of the robot were ascertained as affected by operational variables of robot forward speed (0.17, 0.33 and 0.5 m/s) and payload weight (1, 2, 3, 4 and 5 kN). Analytical results clarified that meaningful contribution of robot forward speed to the motion energy indicators was marginal (<10–35 times) in comparison with that of payload weight. Modeling results described that combinatorial effect of robot forward speed and payload weight on the motion energy indicators was synergetic. This disclosed linear increasing dependency of motion energy consumption (154.02–831.38 J/m2), motion energy dissipation (20.60–165.70 J/m2), and drawbar pull energy (135.96–800.4 J/m2) on concurrent proliferation of robot forward speed and payload weight. The aforementioned amplitudes divulge that 7.20–22.01% of motion energy consumption was dissipated by tracked locomotion system. Overall, these results are profitable for energy-efficient design and performance optimization of tractor-trailer robot with tracked locomotion system in order to proliferate autonomous transportation capacity of payloads, especially for indoor and outdoor shipping and warehouse of factories and industrial environments.

Feasibility of Bluetooth Low Energy for motion capturing with Inertial Measurement Units

Wireless Inertial Measurement Units provide motion capture data with a low hardware cost while offering a lot of mobility for the user. The current solutions rely on Wi-Fi or custom radio protocols, which are usually access point-centre having all the traffic routed through a single access point, limiting direct interaction capabilities with the surrounding devices. Bluetooth Low Energy (BLE) forms point-to-point networks directly between two devices without additional networking, thus, a BLE based motion capture suit could enable seamless direct cooperation between two robots or a human and a robot.In this paper, the feasibility of BLE 5 for motion capturing is investigated by designing and testing an implementation of such a motion capture system using existing commercial hardware. More specifically, a mobile phone was utilized as the receiver device for real-time visualization, whereas BLE sensors were used in order to test the feasibility of the technology for actual use and to identify the bottlenecks in the system for future optimizations. The designed prototype system achieved similar or better performance for the static accuracy and delays in the system when compared to the currently existing commercial suits, while providing a feasible throughput for real-time motion capturing.

Improving soil liquefaction prediction through an extensive database and innovative ground motion characterization: A case study of Port Island liquefied site

Liquefaction is a phenomenon in which soils lose their strength and stiffness significantly during earthquake shakings. It is very important to accurately predict the liquefaction triggering and permanent displacement of liquefied sites under different seismic conditions. This study systematically investigates the effect of ground motion characteristics on the evolution of important physical quantities during the liquefaction process, while the relative capacity of various ground motion intensity measures (IMs) in predicting the pore-pressure generation and the permanent deformation in liquefiable soils are studied. An extensive database containing 501 three-component ground motion records is established to improve soil liquefaction prediction under different earthquake scenarios. A significant number of fully nonlinear dynamic analyses are performed for the Port Island liquefied site, where advanced constitutive models are used to realistically characterize the nonlinear soil behaviors. Results from numerical simulations demonstrate that the energy-related IMs such as CAV5 have a superior predictive capacity than the peak ground acceleration in predicting the liquefaction initiation and permanent displacement, but the predictions based on scalar IMs are not sufficient because residuals are strongly depended on earthquake magnitude and rupture distance. On the other hand, vector IMs that incorporate both energy and peak value characteristics of ground motions can improve the predictive capabilities regarding pore pressure generation and permanent deformation in liquefiable soils. The study helps lay down the basis towards an improved procedure for liquefaction hazard evaluation and mitigation.

Seismic Response Of Multi-storey Building Using Artificial Neural Network

The different parameters like base shear, drift, and top storey displacement of G+7 building is evaluated by using time history analysis and response spectrum analysis for the purpose of comparative study of both the analyses using MATLAB and an artificial neural network (ANN). The main objective of present work is to analyse earthquake of different locations like Bhuj, Kobe, Victoria and Elecentro, for time history analysis building is not connected with actuator and it is analysed during seismic motion of building using a MATLAB software. Base shear, drift and top storey displacement is evaluated during this analysis. For response spectrum analysis, first building relates to actuator at top floor. And during seismic motion of building different parameters like base shear, drift and top floor displacement are evaluated using MATLAB software and for evaluation of control force of a design actuator artificial neural network (ANN) is used. From time history analysis, response spectrum analysis test results and graphs for G+7 building it is clear that, when actuator is not connected with building it does not dissipate the energy of seismic motion and base shear of building , drift , and top floor displacement is very high, and in second case when building is connected with actuator at optimal place it gives considerable response during seismic motion of building and base shear of building, drift, and top floor displacement are can considerably reduce using control actuator system.

Experimental investigation on the mechanical and damping properties of rubber-sand-concrete prepared with recycled waste tires for aseismic isolation layer

Waste tires pose a serious potential threat to environment. Recycling and reusing of waste tires are becoming more important and prevalent. Meanwhile, the aseismic design of underground tunnels requires a material with a low strength able of dissipating the ground motion energy. Therefore, a new type of rubber-sand-concrete (RSC), which is composed of a specific formula of rubber particles, sand, and cement, is proposed. The ingredients proportions in the RSC formula were investigated considering the seismic design demand for underground tunnels. The effects of rubber content (RM), cement content (CM), and rubber particle size (RPS) on the mechanical and damping properties such as density, Poisson's ratio, elastic modulus, compressive and tensile strengths, energy dissipation ability, dynamic shear modulus as well as the damping ratio were discussed. Based on current research, the RM and CM have a notable influence on the mechanical and damping properties, while the influence of RPS is insignificant within a specific range of 0.075–2 mm. When the RM is higher than 30%, or the CM lower than 50%, or the RPS lower than 1 mm in the selected formula scheme, the phase for which the RSC can withstand more deformation before failure is observed. The elastic modulus, compressive and tensile strengths decay exponentially with the RM increase. In addition, the RSC morphological characteristics and energy dissipation performance with different formula schemes subjected to dynamic impacts are presented. The dynamic shear modulus and damping ratio correlation are detailed. Based on the SEM analysis, the influential mechanisms of different ingredients proportions on the RSC properties are discussed.

Energy Harvesting in the Crane-Hoisting Mechanism

The subject of the model research contained in this paper is an application of a motion energy–harvesting device on a crane-hoisting mechanism to power independent measurement devices. Numerical experiments focused on the selected motion energy–harvesting device (M-EHS) and its configuration properties in the context of energy-harvesting efficiency in the case of using it on a crane. The results of the computer simulations were limited to the initial specified conditions for the harvester and the movement of the conditions of the crane-hoisting mechanism. The article compares the energy efficiency for the selected construction and parameters of the harvester for specific hoisting speed and the arm length of the motion conversion system. For this purpose, the initial conditions for the crane and the configuration of parameters of the energy harvester were assumed. The results are visualized on the diagram of RMS voltage induced on piezoelectric elements, showing the impact of individual solutions of the proposed motion energy–harvesting device on the efficiency of energy harvesting. The results of the efficiency of the simulations show that the motion harvester ranges from 0.44 V to 14.22 V, depending on the speed of the crane-hoisting mechanism and the length of the arm of the motion conversion system. Still, the design allows for an adjustment to the given conditions by tuning up the M-EHS to a specified excitation frequency and working conditions.

ANALISIS EFISIENSI SIKLUS RANKINE PEMBANGKIT TENAGA UAP DI PT. PG RAJAWALI II UNIT JATITUJUH

Rankine cycle efficiency and rankine cycle work process at PT. PG Rajawali II Jati Tujuh Unit Adding knowledge to students about Rankine cycle in steam power generation system. To determine efficiency based on operational data. To know and understand the process of the Rankine cycle. It can be a reference and input for PT, PG Rajawali II Unit Jati Tujuh to see its efficiency. Before going into the field, we must prepare our theory according to the title such as boiler, turbine, condenser, pump example. This is a direct observation of the conditions at PT. PG Rajawali II Unit Jati Tujuh. This step is carried out to find out information about the conditions in the field and the situation where the practical work is carried out. Fractional pressure will not occur in the boiler and condenser, if the working fluid flows through the various components of a simple steam power cycle without irreversibility, and the working fluid will flow through the components at constant pressure. Dry water vapor from the boiler enters the turbine and undergoes a process isentropic expansion of the energy stored in the water vapor is converted into motion energy in the turbine. The water vapor is converted into liquid again so that it can be reused in the cycle process, PT. PG Rajawali II Unit Jati Tujuh on October 11, 2020 had the highest efficiency of 25.20%. October 22, 2020 has the lowest efficiency, which is 22.99%. Before going to the work process of the Rankine cycle, we must really understand the components related to the Rankine cycle, starting from the boiler, turbine, condenser, and pump so that we can understand and understand what the Rankine cycle is. In processing data using a help system, namely with Microsoft Excel with engineering applications, we have to ask those who know better so that in processing data with Microsoft Excel it can be actually clear in calculating it to get the values ​​of pressure and temperature and their efficiency.