Tank Track Research Articles

Investigation of Geometric and Hardness Parameters of Tank Track Grooves Equipped on Photovoltaic Cleaning Robot

The utilization of photovoltaic (PV) cleaning robots has proven to be an effective method for maintaining the conversion efficiency of utility-scale PV power plants by mitigating the impact of dust accumulation. However, ensuring the safe operation of these robots, resembling tanks in appearance, particularly in wet working conditions, relies heavily on their adherence to PV panels. This study focuses on assessing the slip resistance of candidate materials coated on endless polyurethane timing belts, which are equipped on PV cleaning robots to enable the efficient cleaning of uneven and misaligned PV arrays. A novel apparatus is proposed to evaluate the coefficient of static friction (COSF) of slip specimens, considering factors such as outsole patterns, area density, and shore hardness. The results highlight the significant influence of shore hardness and area density on the slip resistance of the specimens. Based on the findings, it is recommended to design track grooves with hexagon or zigzag patterns and maintain a low area density (e.g., 0.44 g·mm−2) to ensure the safe operation of PV cleaning robots, irrespective of the working conditions they encounter. By addressing the slip resistance challenge, this research contributes to the overall efficiency and reliability of PV cleaning robots, enhancing their performance in maintaining clean and optimal PV panel surfaces.

High-Order Modeling, Zeroing Dynamics Control, and Perturbations Rejection for Non-Linear Double-Holding Water Tank

The double-holding water tank system is a common non-linear control system that plays a crucial role in process control in the chemical industry. It consists of two cylindrical glass containers: the preset tank and the main tank. The main challenge in controlling this system is adjusting the main control valve to ensure that the actual liquid level of the main tank tracks the desired liquid level. This paper explores the zeroing dynamics (ZD) method and its application in tracking control. A non-linear model is developed for the double-holding water tank system, and the ZD method is used to design an effective controller (called the ZD controller) for tracking control. Additionally, the robustness of the double-holding water tank system in the presence of time-varying perturbations is investigated. In order to substantiate the effectiveness and robustness of the ZD controller, simulation experiments on four different tracking trajectories corresponding to four different practical situations, as well as an extra simulation experiment considering time-varying perturbations, are conducted. Furthermore, a comparative simulation experiment based on the backstepping method is conducted. The presented results successfully illustrate the feasibility and effectiveness of the ZD method for the tracking control of double-holding water tank systems.

부싱 가공 불량 감소를 위한 내경 정밀측정 기반 인라인 가공품질 예측 시스템 개발

A single defect in the bushings of a tank track can cause track breakaway and thus it is important to evaluate the forming accuracy of the bushing during its mass production. In this research, an inline bushing measurement system, comprising of two linear variable differential transformer (LVDT) probes, precision alignment modules, and a stepping motor, was developed for an accurate inner shape prediction and measurement. In addition, an error prediction algorithm was developed for monitoring and controlling the machining quality of the bushing. The inner diameter was calculated by considering the best-fit circle obtained using the LVDT measurement data and the least squares method. The changes in the inner circle diameter were considered to be a machining error due to tool (insert) wear. The measured uncertainty of inner circle diameter was 0.015 mm. The proposed system was verified using the quality decision experimental results of the sample bushing.

H-infinity controller with graphical LMI region profile for liquid slosh suppression

This paper presents a H-infinity synthesis with pole clustering based on LMI region schemes for liquid slosh control. Using LMI approach, the regional pole placement known as LMI region combined with design objective in H-infinity controller guarantee a fast input tracking capability and very minimal liquid slosh. A graphical profile of the transient response of liquid slosh suppression system with respect to pole placement is very useful in giving more flexibility to the researcher in choosing a specific LMI region. With the purpose to confirm the design of control scheme, a liquid slosh model is considered to represent the lateral slosh movement. Supremacy of the proposed approach is shown by comparing the results with hybrid model-free fuzzy-PID controller with derivative filter. The performance of the control schemes is examined in terms of time response specifications of lateral tank tracking capability and level of liquid slosh reduction.

Dual-Side Independent Switched Capacitor Control for Wireless Power Transfer with Coplanar Coils

The transfer coils of traditional Magnetic Coupling Resonant Wireless Power Transfer (MCR-WPT) systems are generally arranged coaxially. Coplanar coils can be an alternative scheme that can save more space in some applications, such as mobile phone wireless charging. However, the inductances of coplanar coils are sensitive to foreign objects, which leads to a reduction in transfer efficiency and output power. A MCR-WPT system with coplanar coils and its control strategy are proposed in this paper. First, the characteristic of the mutual inductance and the magnetic field distribution between the coplanar coils are analyzed. A formula to calculate mutual inductance between the coplanar coils is proposed in this part. Secondly, the effect of inductance offset and frequency detuning on transfer efficiency and output power are analyzed. Then, the control strategy to eliminate frequency detuning is proposed. The proposed method implements switched capacitor to take place of constant compensation capacitor. The equivalent capacitance of switched capacitor is adjusted when the frequency detuning occurred. Thus, the inherent frequency of the resonant tank tracks the source frequency all the time. Since the switched capacitor of each side is controlled based on the quantity of their own, the control process is independent and does not require wireless communication. The complexity and the cost of the system are reduced. At the end of the article, the veracity of mutual inductance formula and the effectiveness of the proposed control strategy are verified by experiments. The experimental coils are placed in in an environment full of interference. The inductances of the coils are reduced from 224 μH to about 214 μH. The transfer efficiency and output power of MCR-WPT system with closed-loop control are higher than the one without control. At a distance of 5 cm from edge to edge, the transfer efficiency is 76.37% under the proposed control and 72.21% under no control. The output power is 285.66 W under the proposed control and 271.37 W under no control.

Automatic fuel tank monitoring, tracking and theft detection system

Automatic fuel tank monitoring, tracking and theft detection system

Unit Cell Synthesis for Design of Materials With Targeted Nonlinear Deformation Response

A systematic unit cell synthesis approach is presented for designing metamaterials from a unit cell level, which are made out of linearly elastic constitutive materials to achieve tunable nonlinear deformation characteristics. This method is expected to serve as an alternative to classical Topology Optimization methods (solid isotropic material with penalization or homogenization) in specific cases by carrying out unit cell synthesis and subsequent size optimization (SO). The unit cells are developed by synthesizing elemental components with simple geometries that display geometric nonlinearity under deformation. The idea is to replace the physical nonlinear behavior of the target material by adding geometric nonlinearities associated with the deforming entities and thus, achieve large overall deformations with small linear strains in each deformed entity. A case study is presented, which uses the proposed method to design a metamaterial that mimics the nonlinear deformation behavior of a military tank track rubber pad under compression. Two unit cell concepts that successfully match the nonlinear target rubber compression curve are evaluated. Conclusions and scope for future work to develop the method are discussed.

“The army and the people are one hand!” Fraternization and the 25th January Egyptian Revolution

AbstractOn 28 January 2011 the Egyptian army was deployed onto Cairo's streets following three days of escalating protests. Upon entering Midan al-Tahrir, a column of newly arriving army tanks and APCs was attacked by protestors. Throwing stones and dousing the vehicles in petrol before setting them alight, protestors pulled soldiers out of their vehicles and beat them. Seizing ammunition and supplies, protestors even commandeered a tank. Minutes later those same protestors were chanting pro-army slogans, posing for photographs with soldiers and sharing food. How protestors respond to the deployment of security forces assumed loyal to a regime determined to end protest is often summed-up in the dyad of “fight or flight.” In this paper, I consider a third option: fraternization. Through a social interactionist lens, I explore the prevalence of pro-army chants, graffiti, the mounting of military vehicles, physical embraces, sleeping in tank tracks and posing for photographs with soldiers in and around Midan al-Tahrir during the 25th January Egyptian Revolution. I draw on the contentious politics literature, as well as micro-sociologies of violence and ritual, to suggest that fraternizing protestors developed a repertoire of contention that made immediate, emotional claims on the loyalty of regime troops. From initial techniques of micro-conflict avoidance, protestors and their micro-interactions with soldiers forged a precarious “internal frontier” that bifurcated governance from sovereignty through the performance of the army and the people as one hand in opposition to the Mubarak regime.

Design of an Innovative Accelerant Detector

Today, canines are still used effectively in acceleration detection situation. However, this method is becoming impractical in modern age and a new automated replacement to the canine is required. This paper reports the design of an innovative accelerant detector. Designing an accelerant detector is a long process as is any design process; therefore, a solution to the need for a mobile, effective accelerant detector is hereby presented. The device is simple and efficient to ensure that any accelerant detection can be conducted quickly and easily. The design utilizes Ultra Violet (UV) light to detect the accelerant. When the UV light shines on an accelerant, the hydrocarbons in the accelerant emit florescence. The advantages of using the UV light to detect accelerant are also outlined in this paper. The mobility of the device is achieved by using a Direct Current (DC) motor to run tank tracks. Tank tracks were chosen as to ensure that the device will be mobile in the rough terrain of a fire site. The materials selected for the various parts are also presented. A Solid Works Simulation was also conducted on the stresses in the shafts and the results are presented. This design is an innovative solution which offers a user friendly interface. The design is also environmentally friendly, ecologically sound and safe to use. Keywords—Accelerant detector, Canines, Gas Chromatography- Mass Spectrometry (GC-MS), Ultra Violet light.

Effects of tank tracking on range grasses

The Department of Defense (DoD) must constantly balance its military mission and its commitment to stewardship on large tracks of federal land. These military training lands are some of the most intensely used land in the United States, and training requires that vegetation, primarily grasses, be as resilient as possible. The objectives of this study were to evaluate (i) plant establishment and (ii) the effect of light to heavy tank traffic that ranged from zero to four passes on range grasses at the Yakima Training Center, Yakima, Washington. Characteristics measured include the number of 10-cm gaps without plant materials in seeded rows of the target (sown) species, the biomass of the target species, and the percentages of bluegrass colonization, bare ground, and cheatgrass encroachment in tracked and untracked areas. Both stand establishment and the ability to produce rhizomes are associated with the ability to recover after training. The wildryes did not establish well and subsequently had more 10-cm gaps and lower yields than the other introduced species tested. Among the natives, Snake River wheatgrass and western wheatgrass exhibited the most resilience across the different tracking intensities. The largest decline in percentage target species was observed between the two- and four-pass treatments. After five years, cheatgrass was not able to encroach on Snake River wheatgrass, Siberian wheatgrass, and bluebunch wheatgrass plots. Tracking generally reduced the stand of the target species and increased the amount of bare ground.

Overwinter changes to near-surface bulk density, penetration resistance and infiltration rates in compacted soil

Previous studies at Yakima Training Center (YTC), in Washington State, suggest freeze-thaw (FT) cycles can ameliorate soil compacted by tracked military vehicles [J. Terramechanics 38 (2001) 133]. However, we know little about the short-term effects of soil freezing over a single winter. We measured bulk density (BD), soil penetration resistance (SPR), and steady-state runoff rates in soil newly tracked by an Abrams tank and in uncompacted soil, before and after a single winter at YTC. We similarly measured BD, SPR and saturated hydraulic conductivity ( k fs) in simulated tank tracks at another site near Lind Washington. Average BD was significantly greater in tank ruts at YTC and in simulated tracks at the Lind site than in uncompacted soil soon after tracking and did not change significantly during the winter of 1997–1998. Measurements of SPR were strongly influenced by soil moisture. When soil was moist or tracks were newly formed, SPR was significantly higher in tank ruts than in uncompacted soil from the surface to a depth of about 10–15 cm. The greatest average SPR in compacted soil was observed between 4 and 6 cm depth. We observed less difference in SPR between tank ruts and uncompacted soil near-surface at YTC as the time after trafficking increased. We observed highest SPR ratios (compacted rut:undisturbed) in fresh tracks near the surface, with lower ratios associated with increasing track age or soil depth, indicating that some recovery had occurred at YTC near-surface. However, we did not observe a similar over-winter change in SPR profiles at the Lind site. Rainfall simulator data from YTC showed higher steady-state runoff rates in tank ruts than over uncompacted soil both before and after winter. However, more time was required to reach steady-state flow in tank ruts and the proportion of runoff was slightly lower in May 1998 than in August 1997. At the Lind site, k fs was lower in newly compacted soil than in one-year old compacted soil or uncompacted soil. Our data suggest that indices of water infiltration such as steady-state runoff rates or k fs, are more sensitive indicators of soil recovery after compaction than are BD or SPR.

Electric field-directed cell motility involves up-regulated expression and asymmetric redistribution of the epidermal growth factor receptors and is enhanced by fibronectin and laminin.

Wounding corneal epithelium establishes a laterally oriented, DC electric field (EF). Corneal epithelial cells (CECs) cultured in similar physiological EFs migrate cathodally, but this requires serum growth factors. Migration depends also on the substrate. On fibronectin (FN) or laminin (LAM) substrates in EF, cells migrated faster and more directly cathodally. This also was serum dependent. Epidermal growth factor (EGF) restored cathodal-directed migration in serum-free medium. Therefore, the hypothesis that EGF is a serum constituent underlying both field-directed migration and enhanced migration on ECM molecules was tested. We used immunofluorescence, flow cytometry, and confocal microscopy and report that 1) EF exposure up-regulated the EGF receptor (EGFR); so also did growing cells on substrates of FN or LAM; and 2) EGFRs and actin accumulated in the cathodal-directed half of CECs, within 10 min in EF. The cathodal asymmetry of EGFR and actin staining was correlated, being most marked at the cell-substrate interface and showing similar patterns of asymmetry at various levels through a cell. At the cell-substrate interface, EGFRs and actin frequently colocalized as interdigitated, punctate spots resembling tank tracks. Cathodal accumulation of EGFR and actin did not occur in the absence of serum but were restored by adding ligand to serum-free medium. Inhibition of MAPK, one second messenger engaged by EGF, significantly reduced EF-directed cell migration. Transforming growth factor beta and fibroblast growth factor also restored cathodal-directed cell migration in serum-free medium. However, longer EF exposure was needed to show clear asymmetric distribution of the receptors for transforming growth factor beta and fibroblast growth factor. We propose that up-regulated expression and redistribution of EGFRs underlie cathodal-directed migration of CECs and directed migration induced by EF on FN and LAM.

Short-Term Influence of Tank Tracks on Vegetation and Microphytic Crusts in Shrubsteppe Habitat

/ I examined vegetation and microphytic crust cover on two sites in burned and two sites in unburned big sagebrush (Artemisia tridentata Nutt.) habitat within the Idaho Army National Guard Orchard Training Area in southwestern Idaho. The purpose of this study was to determine the short-term (1-2 years) influence of tank tracks on vegetation and microphytic crusts in shrubsteppe habitat. The two types of tank tracks studied were divots (area where one track has been stopped or slowed to make a sharp turn) and straight-line tracks. Divots generally had a stronger influence on vegetation and microphytic crusts than did straight-line tracks. Tank tracks increased cover of bare ground, litter, and exotic annuals, and reduced cover of vegetation, perennial native grasses, sagebrush, and microphytic crusts. Increased bare ground and reduced cover of vegetation and microphytic crusts caused by tank tracks increase the potential for soil erosion and may reduce ecosystem productivity. Reduced sagebrush cover caused by tank tracks may reduce habitat quality for rodents. Tank tracks may also facilitate the invasion of exotic annuals into sagebrush habitat, increasing the potential for wildfire and subsequent habitat degradation. Thus, creation of divots and movement through sagebrush habitat by tanks should be minimized.KEY WORDS: Divots; Fire history; Idaho; Military; Sagebrush; Straight-line tracks

Effect of ageing on strength and wear of tank track pad compounds

The effect of ageing on the strength and wear of natural rubber (NR), styrene-butadiene rubber (SBR), NR-SBR blends and hydrogenated nitrile rubber (HNBR) based tank track pad compounds has been investigated over a range of ageing temperatures and times. HNBR compounds show a stable ageing resistance at all the ageing temperatures (75–125 °C); the other compounds lose about 60%–90% of their original strength, indicating their unserviceability above 75 °C. The HNBR compound shows excellent abrasion resistance even after ageing at 125 °C for 72 h, and its abrasion resistance is about six to seven times higher than that of the other compounds. The results are explained on the basis of relative thermo-oxidative degradation resistance. Microscopic investigation of the abraded surface of HNBR shows only scratch marks, indicating abrasive wear as the principal mechanism of wear, while the other compounds undergo wear by a pattern abrasion mechanism. Abradability is related to the reciprocal of breaking energy.

The effect of crosslink density, curing system, filler and resin on the decomposition of hydrogenated nitrile rubber and its blends

The decomposition behaviour and kinetics of oxidative decomposition of hydrogenated nitrile rubber (HNBR), zinc-poly(methyl methacrylate) resin (ZSC-2295) and the tank track pad compositions developed from their blends have been studied by thermogravimetry in air and compared with those of natural rubber (NR) and styrene-butadiene rubber (SBR) based compositions. The effect of crosslink density, curing system and carbon black on the degradation characteristics of HNBR have also been investigated. HNBR undergoes first order and ZSC-2295 undergoes second order degradation with an activation energy (Δ E a) of 330 ± 10 and 400 ± 10 kJ mol −1 respectively. The degradation characteristics and kinetics are not influenced by the crosslink density, the curing system or the carbon black loading. The (Δ E a), of the degradation reaction of HNBR based compositions increases slightly on the addition of the resin ZSC-2295. Degradative stability in terms of onset and peak temperature of degradation and (Δ E a) of degradation of the tank track pad compositions follow the order HNBR > SBR > NR.

Wear of Tank Track Pad Rubber Vulcanizates by Various Rocks

Abstract Wear of tank track pad compounds against various rocks at different normal loads and frictional work has been investigated. The track pads have been based on natural rubber (NR) and hydrogenated nitrile rubber (HNBR). The rocks have various hardness and chemical compositions. Wear, V, increases with normal load, N, and frictional work, F, and is related by V=KFn, where k and n are constants. The value of n is lower for filled compounds and abrasion against soft rock. At any normal load, the rate of wear of HNBR is much lower than that of NR, though the temperature developed is higher for HNBR compounds. All the results could be explained with the help of dynamic coefficient of friction, frictional work, and structural changes during abrasion. Ridges are found on the abraded surface of NR, and the surface is tarry. A dry and particulate wear is observed in HNBR compounds, and the size of debris increases with frictional work.

Pattern Abrasion and Other Mechanisms of Wear of Tank Track Pads

Abstract Wear of tank track pads has been studied under different conditions. With T142 pads tested on an M-60 tank, the mode of failure was found to depend on the test conditions. Among eighteen experimental compounds tested, improved wear (vs. the standard compound) under one test condition was generally at the expense of poorer wear under one or both of the other test conditions. However, in agreement with previous results, an HNBR/Zn-methacrylate/peroxide compound gave improved wear rate under all three test conditions. Wear of the T142 pads on a hilly cross-country course and on a combination course was generally by massive chunking. On a paved road course, most compounds wore by pattern abrasion. A few compounds worn on this course formed deep pockets parallel to the surface, resulting in the eventual loss of the large flaps between the pocket and the surface. Pattern abrasion was also found on T156 pads of four different compounds, tested on an M-1 tank on the paved road course. The abrasion patterns of both types of pads had a shingled appearance, with the ridges pitched so as to bite into the road surface. The abrasion patterns were characterized quantitatively by profilometry, using standard parameters calculated for surface roughness of metals and other materials. The ridge height and its ratio to ridge spacing correlated positively with wear rate on the paved road; whereas there was no correlation of ridge spacing with wear rate. The compounds which gave the lowest wear rate on the paved road, including the HNBR compounds, gave shallow ridges with little or no pattern.

The New Europe: Yesterday's Ghosts

LAST YEAR was not a good year for Europe, and the disease was renationalization?on cats' feet in the West and on tank tracks in the East. History, it turned out, had not ended with the champagne party atop the breached Berlin Wall in November 1989, the reunification of Germany in October 1990 or the dissolution of the Soviet Union in December 1991. History in fact came back with a vengeance, and nowhere more fiercely than where it had been most suppressed: in the Soviet empire and in the artificial nation-state of Yugoslavia. Nor was the return of history a mere accident. For 600 years European history has been written by states forming and reforming around the idea of the nation-state. In 1945 that saga suddenly ended. Two empires shouldered aside the notion of the nation-state?one formed voluntarily under American tutelage in the West, another held together in the Soviet grip in the East. But on December 25, 1991, the Red Flag was hauled down from the Kremlin, and the Soviet empire was no more. In the East, where nationality had been suppressed by an authoritarian regime and an alien universal ist ideology, the end of the empire spelled the immediate rebirth of nation-states: Russia, Belarus, Ukraine, Estonia, Latvia and Lithuania. Farther south, in the Balkans, a multi national construction called Yugoslavia disintegrated loudly into a war that might yet spread to the entire region. In the West the process was more subtle. To begin with, there had never really been an empire under an American flag; it was an American-sponsored community under U.S. protection whose members retained their sovereignty and much of their autonomy. But the community's original and most powerful raison d'?tre?the Soviet threat?faded in 1990

The Direction of Membrane Lipid Flow in Locomoting Polymorphonuclear Leukocytes

The objective of this study was to determine the direction of membrane lipid flow in locomoting cells. The plasma membrane of human polymorphonuclear leukocytes was stained with a fluorescent lipid analog dihexadecanoyl indocarbocyanine. A line was photobleached on the cell surface perpendicular to the direction of cell motion. Low-light-level fluorescence microscopy and digital image-processing techniques were used to analyze a series of images taken at short intervals after photobleaching. The bleached line remained visible for about 5 seconds before being erased by diffusional recovery. Examination of fluorescence intensity profiles allowed a comparison to be made between the velocities of line and cell movement. Results indicate that the bleached line moves forward with the same velocity as the cell during locomotion, refuting the retrograde lipid flow model of locomotion. Instead, the plasma membrane lipid appears to move forward according to either the unit movement of membrane or the tank track model of locomotion.

Persisting effects of armored military maneuvers on some soils of the Mojave Desert

Soil compaction and substrate modification produced during large-scale armored military maneuvers in the early 1940s were examined in 1981 at seven sites in California’s eastern Mojave Desert Recording penetrometer measurements show that tracks left by a single pass of an M3 “medium” tank have average soil resistance values that are 50% greater than those of the surrounding untracked soil in the upper 20 cm At one site, measurements made along short segments of track that have been visually eliminated by erosion and deposition processes show a 73% increase in penetrometer resistance over adjacent, undisturbed soils Dirt roadways at three former base camp locations could not be penetrated below 5–10 cm because of extreme compaction Soil bulk density was not as sensitive an indicator of soil compaction as was penetrometer resistance Density values in the upper 10 cm of soil are not significantly different between tank tracks and undisturbed soils at most sites, and roadways at two base camps show an average increase in bulk density of only 12% over adjacent soils. Trench excavations across tank tracks show that physical modifications of the substrate can extend vertically beneath a track to a depth of 25 cm and outward from a track’s edge to 50 cm These soil disturbances are probably major factors that encourage accelerated soil erosion throughout the manuever area and also retard or prevent the return of vegetation to pre-disturbance conditions