Motor Arrangement Research Articles

Thermal analysis of an integrated motor drive with a switching cell array power converter

In modern electric propulsion systems the electric motor is tightly integrated with the power converter and control unit. These so called Integrated Motor Drives can allow for vast improvements in efficiency and volume reduction, due to the elimination of redundant electric components, and the shared case and cooling system between the motor and the power converter. The cooling systems used in these applications must be carefully designed as the motor and power electronics components may feature greatly different temperature limits. This work discusses the development of a thermal model for an integrated motor drive composed by a six phase permanent magnet motor with hairpin windings and a switching-cell-array-based multilevel power converter. The system is modelled by means of a lumped parameter thermal network which includes an accurate model of the motor stator and rotor, as well as the arrangement of the power switches on the converter boards. The conductive resistances are simply obtained from geometric data and material properties. Instead, the convective resistances are evaluated by means of empirical models available in the literature and a CFD model for the cooling jacket. The developed model is employed to assess the feasibility of the presented arrangement of motor and power electronics components from the thermal point of view.

Design and validation of a pediatric gait assistance exoskeleton system with fast non-singular terminal sliding mode controller

Existing exoskeletons for pediatric gait assistance have limitations in anthropometric design, structure weight, cost, user safety features, and adaptability to diverse users. Additionally, creating precise models for pediatric rehabilitation is difficult because the rapid anthropometric changes in children result in unknown model parameters. Furthermore, external disruptions, like unpredictable movements and involuntary muscle contractions, add complexity to the control schemes that need to be managed. To overcome these limitations, this study aims to develop an affordable stand-aided lower-limb exoskeleton specifically for pediatric subjects (8-12 years, 25-40 kg, 128-132 cm) in passive-assist mode. The authors modified a previously developed model (LLESv1) for improved rigidity, reduced mass, simplified motor arrangement, variable waist size, and enhanced mobility. A computer-aided design of the new exoskeleton system (LLESv2) is presented. The developed prototype of the exoskeleton appended with a pediatric subject (age: 12 years old, body mass: 40 kg, body height: 132 cm) is presented with real-time hardware architecture. Thereafter, an improved fast non-singular terminal sliding mode (IFNSTSM) control scheme is proposed, incorporating a double exponential reaching law for expedited error convergence and enhanced stability. The Lyapunov stability warrants the control system's performance despite uncertainties and disturbances. In contrast to fast non-singular terminal sliding mode (FNSTSM) control and time-scaling sliding mode (TSSM) control, experimental validation demonstrates the effectiveness of IFNSTSM control by a respective average of 5.39% and 42.1% in tracking desired joint trajectories with minimal and rapid finite time converging errors. Moreover, the exoskeleton with the proposed IFNSTSM control requires significantly lesser control efforts than the exoskeleton using contrast FNSTSM control. The Bland-Altman analysis indicates that although there is a minimal mean difference in variables when employing FNSTSM and IFNSTSM controllers, the latter exhibits significant performance variations as the mean of variables changes. This research contributes to affordable and effective pediatric gait assistance, improving rehabilitation outcomes and enhancing mobility support.

Design and Implementation of a Semantic Information Expression Device Based on Vibrotactile Coding

In recent years, research on new technologies for expressing and exchanging information through tactile vibration has been the focus of researches. In this paper, by choosing a suitable coding scheme and a vibrating motor arrangement, we designed a device to express semantic information through vibrotactile. Three types of experiments were designed to test the usability of the encoding scheme and the device. Firstly, the vibration intensity was experimented when designing the encoding scheme, and the results showed that the encoding scheme was better with Braille units of 0.2 and 0.3 vibration intensities. In addition, the learning experiment and sentence recognition accuracy experiment were carried out to verify the usability of the device. The learning experiment results show that subjects were able to memorize Braille characters with an accuracy more than 90%, and to recognize a Chinese character (consisting of two Braille cells) with an average of 90.8% accuracy. The sentence recognition accuracy test experiment results show that the average recognition rate of the three poems used for the test was 93.33%. The device can be used for semantic information expression and touch-reading of Braille, and it can realize the reading experience of paper Braille.

Cargo transport properties are enhanced by cylindrical microtubule geometry and elliptical contact zone on cargo surface

Molecular motors are responsible for carrying cellular transport of various membranous vesicles or organelles along cytoskeletal tracks. Transport of cellular cargos require high forces that are generated by motors working in groups. Hence, the properties of cargo transport can be modulated by varying various parameters such as cargo size and shape, microtubule geometry, motor number and their arrangement on cargo surface. Only those motors which are present in the contact zone on cargo surface have potential to bind to microtubule. Although earlier studies revealed the importance of cargo size, total motors attached to microtubule and their arrangement on cargo transport, yet how the contact zone influences binding of motors to microtubule largely remains unexplored. Here, it has been shown that contact zone is elliptical in shape for a spherical cargo and increases with cargo size for Kinesin-1 motors. To further understand the combined effect of elliptical contact zone and microtubule geometry on cargo transport, 3D mean-field model with uniform and clustered arrangement of motors for different cargo sizes and motor number has been used. Our findings indicate that cylindrical microtubule geometry maximizes the microtubule-bound motors which enhances the runlength and velocity of cargo transport. Our results show that microtubule-bound motors decrease with cargo size for uniform arrangement of motors on cargo thus decreasing its runlength and velocity, whereas in clustered arrangement, the number of microtubule-bound motors increase with cargo size which leads to increase in runlength and velocity.

In-series vs. in-parallel: The role of cargo-motor connectivity in transport by ensembles of cytoskeletal motor proteins.

The movement of the cytoskeletal molecular motor proteins dynein and kinesin on microtubule networks facilitates the complex intracellular organization of eukaryotic cells. Ensembles of these motors are a prevalent feature of cytoskeletal transport, indicating possible synergistic effects of their use for intracellular organization. While the force output of individual motors is well studied, the mechanisms governing emergent force generated by multiple motors acting as an ensemble remains unclear. Determining the fundamental mechanisms controlling the interaction and integration of the forces produced by these motors at the nanoscale is essential to understanding the broader system of intracellular transport. Using total internal reflection fluorescence (TIRF) microscopy, we are investigating the role of the spatial arrangement of motors in an ensemble with a particular emphasis on the connectivity between motors and their cargo. Using motors purified from yeast and the nanoscale construction techniques of DNA origami, we create programmable chassis structures in which multiple cytoplasmic dyneins or Kip2 kinesins are arranged with independent, “in parallel” connections to a resistive cargo load or, in contrast, are arranged with a single, “in series” shared cargo connection. We expect the use of these chassis will allow us to determine the mechanisms behind the structural integration of the piconewton forces produced by cytoskeletal molecular motors within ensembles, ultimately providing insight on how the individual connectivity of motors to one another and their cargo affects load-sharing, force integration, and the resultant emergent motility of the motor ensemble.

Spinal premotor interneurons controlling antagonistic muscles are spatially intermingled.

Elaborate behaviours are produced by tightly controlled flexor-extensor motor neuron activation patterns. Motor neurons are regulated by a network of interneurons within the spinal cord, but the computational processes involved in motor control are not fully understood. The neuroanatomical arrangement of motor and premotor neurons into topographic patterns related to their controlled muscles is thought to facilitate how information is processed by spinal circuits. Rabies retrograde monosynaptic tracing has been used to label premotor interneurons innervating specific motor neuron pools, with previous studies reporting topographic mediolateral positional biases in flexor and extensor premotor interneurons. To more precisely define how premotor interneurons contacting specific motor pools are organized, we used multiple complementary viral-tracing approaches in mice to minimize systematic biases associated with each method. Contrary to expectations, we found that premotor interneurons contacting motor pools controlling flexion and extension of the ankle are highly intermingled rather than segregated into specific domains like motor neurons. Thus, premotor spinal neurons controlling different muscles process motor instructions in the absence of clear spatial patterns among the flexor-extensor circuit components.

Active Microphase Separation in Mixtures of Microtubules and Tip-Accumulating Molecular Motors.

Mixtures of filaments and molecular motors form active materials with diverse dynamical behaviors that vary based on their constituents' molecular properties. To develop a multiscale of these materials, we map the nonequilibrium phase diagram of microtubules and tip-accumulating kinesin-4 molecular motors. We find that kinesin-4 can drive either global contractions or turbulentlike extensile dynamics, depending on the concentrations of both microtubules and a bundling agent. We also observe a range of spatially heterogeneous nonequilibrium phases, including finite-sized radial asters, 1D wormlike chains, extended 2D bilayers, and system-spanning 3D active foams. Finally, we describe intricate kinetic pathways that yield microphase separated structures and arise from the inherent frustration between the orientational order of filamentous microtubules and the positional order of tip-accumulating molecular motors. Our work reveals a range of novel active states. It also shows that the form of active stresses is not solely dictated by the properties of individual motors and filaments, but is also contingent on the constituent concentrations and spatial arrangement of motors on the filaments.

Design and Fabrications of Vibrating Table for Concrete Mould

Abstract: The proposed concept in this project is to use vibrations to replace human labor of eliminating air bubbles from concrete blocks with the help of a vibrating motor arrangement. Concrete is made up of aggregate, water, and cement in a composite form. They generate a mass fluid that can be easily molded into different shapes for varied functions when combined in certain ratios. Concrete must be free of entrapped air and voids to achieve the appropriate strengths. Concrete consolidation is used to accomplish this. The process of eliminating entrapped air from a concrete mold is known as consolidation. Unbalanced eccentric assembly, stand frame, top plate as platform, springs, spring suspension system, and electric motor are the primary components. A lot of mistakes should be made when a person works by hand. It also required lots of workers and production does not come in required amount during that day so the vibrating table will save time as well as money. The removal of these spaces enhances the exterior surface of the molded concrete, allowing for the use of less water with cement, resulting in a considerably stronger finished product, and this was accomplished using a vibrating table. The goal of this project is to build a concrete vibrating table that efficiently ensures concrete consolidation for a better product. These concrete molds can be used to make concrete roof tiles and concrete paving bricks. Although there are various existing vibrating tables, our job was to develop and maybe manufacture an improved vibrating table using locally available materials

Implementation of Barrier Sensing and Avoidance System on FPGA for a Wheeled Robot

Aims: This paper is to describe the process of spotting a barrier on the path of a wheeled robot and finding an alternate way to keep away from it. Method: For path, planning, image-processing technique is used and for this barrier-sensing and avoidance system, ultrasonic sensor is used. FPGA board processes the sensor output and after processing, it gives instruction to the motor arrangement to control the speed and direction of the wheeled robot. Results: We took one digital storage oscilloscope to collect all the data from sensor board. Although the color and lumen of the reflection matters a lot in the reading, so a variety of different objects we have selected to reduce the probability of error. A Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL) block we generate for control algorithm and connect to the enable pin. Fig-8 shows the calculation block and fig-9 shows the ADC. As the FPGA board reads digital signal, hence the received signal we converted to digital with the help of an ADC of type NS ADC128S022. It is a 12-bit converter. Initially a bigger particle we kept in front of the sensor to understand and quantify the highest scope of it. DSO we used to view the response of both pulse and the analog signal. The code, which we have written for the operation of the ultrasonic sensor, has used a high logic of 10 µs width for triggering input. Program is measuring the object distance by calculating the logic high time of the ECHO pin that we have programmed as input. For servo operation, a pulse we used with 1.5ms on time and 20-millisecond time-period. To change the rotating angle different on time we have adopted. Conclusion: Wheeled robots have a no of applications. Depending on what sensor people use or what actuators or microprocessors they apply, the response time differs from one model to the other. To use it in real time applications a robot should give very fast response. In realistic approach FPGA development board is widely used in robot models recently because of its very fast response time, flexible system approach, quick generation of signals, parallel processing ability and obviously cost is pretty less when compared to other processor. References, figures, tables, chemical structures etc.

3D printed protein-based robotic structures actuated by molecular motor assemblies

Upscaling motor protein activity to perform work in man-made devices has long been an ambitious goal in bionanotechnology. The use of hierarchical motor assemblies, as realized in sarcomeres, has so far been complicated by the challenges of arranging sufficiently high numbers of motor proteins with nanoscopic precision. Here, we describe an alternative approach based on actomyosin cortex-like force production, allowing low complexity motor arrangements in a contractile meshwork that can be coated onto soft objects and locally activated by ATP. The design is reminiscent of a motorized exoskeleton actuating protein-based robotic structures from the outside. It readily supports the connection and assembly of micro-three-dimensional printed modules into larger structures, thereby scaling up mechanical work. We provide an analytical model of force production in these systems and demonstrate the design flexibility by three-dimensional printed units performing complex mechanical tasks, such as microhands and microarms that can grasp and wave following light activation.

Development and actuation analysis of shape memory alloy reinforced composite fin for aerodynamic application

In this investigation, a shape memory alloy (SMA) based aerodynamic composite Fin has been developed. In general, the missile fins play a crucial role in changing the direction of a conventional missile using motor arrangement. Therefore, SMA-based composite Fin might be a promising alternative to control the direction without using the motor. The composite Fin is made of laminated fiber polymer and SMA wire. Initially, rectangular composite structures have been developed with different wire prestraining percentages, lengths, diameters, and configurations to understand their electrical actuation behavior. Based on the experiments, optimized parameters have been derived and applied to the composite fin. Adaptive composite actuation was performed via selective joule heating on the composite fin. Under optimized conditions, SMA-based composite structure shows maximum displacement of 65 mm with a maximum angle of 60 degrees before failure, where the diameter of 5 % pre-strained SMA wire was 0.5 mm at 6 % of SMA to Composite ratio (volume of SMA/volume of composite). Maximum displacement and failure analysis of the composite structure has been analyzed at optimized parameters.

Performance of cylindrical parabolic solar collector with the tracking system

A parabolic solar collector collects the radiant energy emitted from the sun and focuses on a point. Parabolic trough collectors are the low-cost implementation of concentrated solar power technology that focuses incident sunlight onto a tube filled with a heat transfer fluid. However, the fundamental problem with the cylindrical parabolic collector without tracking was that the solar collector does not move with the sun's orientation. The development of an automatic tracking system for cylindrical parabolic collectors will increase solar collection and the efficiency of devices. The present study of this project work presents an experimental platform based on the design, development, and performance characteristic of water heating by tracking solar cylindrical parabolic concentrating system. The tracking mechanism is to be made by stepper motor arrangement to receive the maximum possible energy of solar radiation as it tracks the sun's path. The performance of the parabolic trough collectors is experimentally investigated with the water circulated as heat transfer fluid. The collector efficiency is calculated.

Effects of Jet Flow Pulsation on Diffusion Flame Performance

he objective of the current research is the experimental investigation of the pulsating flow effects on the combustion performance in terms of the flame temperature distribution, the heat transfer rate, the combustion efficiency and the exhaust gas analysis. The flow pulsation provided through a rotary ball valve in accordance with a variable speed motor arrangement increased the flame temperature fluctuation and the magnitude of heat release. The flow pulsation provides a highly turbulent flame wherein the vortices are enlarged. Increasing Strouhal number [St] of the LPG fuel and air flow increases the time-averaged flame temperature of the pulsating flame up to a saturation level that is dictated by the heat transfer rate enhancement. The maximum average flame temperature is 1263oC at St= 0.041, r= 0 mm and 100 mm from the burner inlet. In addition, increasing the pulsating flow amplitude increases the convection and radiation heat fluxes from the pulsating flame. While increasing the pulsation decreases the exhaust UHC due to increasing the turbulent kinetic energy across the pulsating flame, the exhaust NOx slightly increases due to increasing the heat release rate and the flame temperatures. Pulsation thus enhances the combustion efficiency inside the industrial combustors.

Comparison between Frequency Response of Pulsating Partially Premixed and Diffusion Flame

The objective of the current research is investigation of the pulsating flow effect on the size of partially premixed and diffusion flame, experimentally. The pulsation provided through a rotary ball valve in accordance with a variable speed motor arrangement increased the flame temperature and thus more heat is released. The used S-type thermocouple can measure the flame temperature at strouhal number [St] is 0 and 0.005 for the flow, the flame temperature has been measured at five planes as each plane has five radii. Fast Fourier Transform (FFT) has been used to determine the dominant frequency response of the pulsating flame temperatures. Increasing strouhal number of the mixture (LPG fuel and air) flow increases the turbulence intensity and thus the dominant frequency response of the pulsating flame increases. The dominant frequency at St=0 is larger than the dominant frequency at St= 0.005 for all the planes of the combustion chamber. Increasing strouhal number reduces the size of the pulsating partially premixed and diffusion flame by a maximum of 40 and 35 %, respectively. The pulsation process will optimize design of the burners.

Molecular Nano-Patterning Reveals Different Coordination of Kinesin-1 and Kinesin-14 Motors

Kinesin is a motor protein that is necessary for various cellular processes including intracellular transport, cell division, and flagellar motility. In vivo, multiple kinesin motors are bound to a cargo and work as a team to produce larger forces or faster speed than a single kinesin motor. However, the coordination of motors remains poorly understood because of the experimental difficulty in controlling the number and arrangement of motors, which are considered to affect their coordination. Here we develop a nano-patterning method of kinesin motors that enables to control the number and spacing of kinesin motors transporting a single microtubule filament. Using this method, we show that both the number and spacing significantly influence the velocity of microtubules driven by non-processive kinesin-14, whereas neither the number nor the spacing changes the velocity in the case of highly processive kinesin-1. In detail, the velocity decreased with an increase in the number of kinesin-14 motors in the range of 3-10 motors. This result implies that kinesin-14 motors hinder each other's movement during collective transport. We also obtained the unexpected dependence of velocity on spacing; the velocity increased with an increase in the spacing of kinesin-14 motors in the range of 0.2-0.6 µm spacing. This result indicates that, although kinesin-14 motors interfere with each other, the interaction was weakened with increasing spacing of kinesin-14 motors. Our results reveal new insight into different coordination of kinesin-1 and kinesin-14 motor proteins, and interaction between kinesin motors during collective transport. As the proposed method is applicable for various motor species such as kinesin-5 and kinesin-7, it can be a powerful assay platform to study the coordination of motors.

Collective motility of dynein linear arrays built on DNA nanotubes

Dynein motor proteins usually work as a group in vesicle transport, mitosis, and ciliary/flagellar beating inside cells. Despite the obvious importance of the functions of dynein, the effect of inter-dynein interactions on collective motility remains poorly understood due to the difficulty in building large dynein ensembles with defined geometry. Here, we describe a method to build dynein ensembles to investigate the collective motility of dynein on microtubules. Using electron microscopy, we show that tens to hundreds of cytoplasmic dynein monomers were anchored along a 4- or 10-helix DNA nanotube with an average periodicity of 19 or 44 nm (a programmed periodicity of 14 or 28 nm, respectively). They drove the sliding movement of DNA nanotubes along microtubules at a velocity of 170–620 nm/s. Reducing the stiffness of DNA nanotubes made the nanotube movement discontinuous and considerably slower. Decreasing the spacing between motors simply slowed down the nanotube movement. This slowdown was independent of the number of motors involved but heavily dependent on motor–motor distance. This suggests that steric hindrance or mechanical coupling between dynein molecules was responsible for the slowdown. Furthermore, we observed cyclical buckling of DNA nanotubes on microtubules, reminiscent of ciliary/flagellar beating. These results highlight the importance of the geometric arrangement of dynein motors on their collective motility.

Aspects concerning the influence of the design of flameproof electric motors on maximum explosion pressures

The research carried out in the specialized Laboratory of the National Institute for Research and Development in Mine Safety and Explosion Protection INSEMEX Petrosani has identified as causes for the occurrence of high pressure peaks in the case of electric motor enclosures, the internal volume, the geometrical shape of motor enclosures and the very intricate and complex internal arrangement of such motor enclosures (especially in the case of large motor enclosures), having in mind the tendency of motor manufacturers for chemical and petrochemical industry to manufacture motors having more complex geometrical shapes.

Flap system power drive unit (PDU) architecture optimisation

Conventional flap and slat high-lift surfaces actuation systems in a commercial aircraft consist of actuators mechanically connected via a transmission system across the wingspan, driven from a centralised power drive unit comprising of a hydraulic, electric, or hybrid hydraulic/electric motor arrangement. The permanent coupling to the shafts makes the entire flap system move in unison, as do the slats. This paper will investigate and discuss different potential system architecture, and present the benefits associated with such architecture. It will also present the advantage that can be linked to a full electric flap configuration.

Late Endosomal Membrane-Lipid Composition Imparts Change in Oxysterol-Binding Protein-Related Protein 1L's (ORP1L) Nano-Scale Organization Which Effects Organelle Motility

Intracellular organelle transport along microtubules (MTs) is highly regulated spatiotemporally and is orchestrated by motor proteins dynein and kinesins. The directionality and uninterrupted long-range motion of the organelles are achieved by multilevel regulatory mechanisms including motor recruitment and motor activation by adapter and accessory proteins. Recently, the motor organization on organelle membranes, in particular motor clustering, has been suggested to play an important role in transport regulation and processes including organelle biogenesis and maturation. While the lipid composition of the organelle membrane, specifically the cholesterol content, has been suggested to play a role in regulating the molecular arrangement or clustered organization of motors, the exact mechanisms are not clear. We hypothesized that clustering/molecular organization of the motor protein dynein is mediated by the nanoscale organization of Oxysterol-Binding Protein-Related Protein 1L (ORP1L), which is the main cholesterol sensing protein present on late endosomal, lysosomal and phagosomal compartments. To determine the dependence of motor and ORP1L nano-organization on cholesterol levels, we have been using Stochastic Optical Reconstruction Microscopy (STORM). We found that motor proteins like dynein and ORP1L indeed form nano-clusters on late endosomal membranes. By coupling super-resolution imaging with drug treatments that modulate the cholesterol content of organelle membranes, we observed ORP1L nano-organization is sensitive to cholesterol content of the late endosomal membrane. Using quantitative analysis, we showed that ORP1L is more clustered on late endosomal membranes under high cholesterol conditions compared to low cholesterol conditions. Further, high cholesterol led to a redistribution and repositioning of late endosomes at the peri-nuclear region, suggesting that dynein activity and dynein mediated motility are sensitive to cholesterol levels. Overall using high resolution microscopy we are dissecting the link between organelle membrane nano-organization and organelle motility/positioning.

Transport of microtubules according to the number and spacing of kinesin motors on gold nano-pillars.

Motor proteins function in in vivo ensembles to achieve cargo transport, flagellum motion, and mitotic cell division. Although the cooperativity of multiple motors is indispensable for physiological function, reconstituting the arrangement of motors in vitro is challenging, so detailed analysis of the functions of motor ensembles has not yet been achieved. Here, we developed an assay platform to study the motility of microtubules driven by a defined number of kinesin motors spaced in a definite manner. Gold (Au) nano-pillar arrays were fabricated on a silicon/silicon dioxide (Si/SiO2) substrate with spacings of 100 nm to 500 nm. The thiol-polyethylene glycol (PEG)-biotin self-assembled monolayer (SAM) and silane-PEG-CH3 SAM were then selectively formed on the pillars and SiO2 surface, respectively. This allowed for both immobilization of kinesin molecules on Au nano-pillars in a precise manner and repulsion of kinesins from the SiO2 surface. Using arrayed kinesin motors, we report that motor number and spacing do not influence the motility of microtubules driven by kinesin-1 motors. This assay platform is applicable to all kinds of biotinylated motors, allows the study of the effects of motor number and spacing, and is expected to reveal novel behaviors of motor proteins.