Powerful Motor Research Articles

Design optimization of industrial robot arm to minimize redundant weight

In industrial robots, projected torque increases depending on the extending reach length and payload. This requires selection of powerful motors particularly on the second axis. Since arm rigidity becomes more important as the expected positioning precision increases, less flexible materials are used. Therefore, during operation conditions, 70% of motor’s energy is used for redundant weight. In this study, analyses conducted on five different robotic arms belong to different brands. Arm’s payload distribution in terms of region and amount is examined, alternative designs are analysed and compared with each other. Geometry and materials are changed in alternative designs. In this way, redundant weight is minimized (without increasing the share amount) at the same positioning precision. Results of this study demonstrated a 10% decrease in inert payloads.

Increasing the Accuracy of Measuring the Resistance of the Grounding System with an Electrodeless Method

Recently, electrodeless methods of measuring the resistance of grounding devices have appeared, with the help of special clamps. But a large methodological error limits the possibility of their use, especially when rationing low resistances. The article shows the possibility to improve the accuracy of electrodeless measurement methods using commercially available measuring instruments.In electrical installations of telecommunication networks of buildings, structures and industrial enterprises, the form of the AC voltage signal of the industrial supply network (~220V, 50/60Hz) can be differ greatly from the sinusoidal for short periods of time. The causes of distortions are usually associated with a sudden change in the network load [1], for example, when you turn on a powerful electric motor, furnace, welding machine, etc.The occurrence of impulse overvoltages and interference caused by electromagnetic effects (lightning, switching, radio frequency and others) on low-voltage networks, not only leads to failure of electrical installations, cables, switchboards, but also to damage the terminal equipment and malfunction. This is due, primarily, to the saturation of modern buildings and structures with information, telecommunications and other digital equipment, which has a very low level of protection against impulse overvoltages and interference. All this makes it necessary to carry out appropriate protective measures. To reduce interference, it is necessary to perform a separate (working) ground loop, the resistance of which must be measured and periodically monitored.There are devices that allow an electrodeless method to monitor and evaluate the resistance of the ground loop. But these devices have a greater measurement error than devices that measure the resistance of the earth electrode method.The article deals with existing instruments (CA6410, MZC-303E) which can evaluate the resistance of the earth electrode and the possibility of increasing the accuracy of the measurement with the help of special current clamps is shown. Using a predetermined value of neutral impedance, the measurement error of the calculated resistance of the earthing switch can be determined with great accuracy.

Accounting of energy consumption of passenger electric locomotives in locomotive operational depots

Energy efficiency of transportation process is constantly in the center of attention of specialists and managers of Russian Railways. Some of the new electric locomotives purchased under the investment project have shown unsatisfactory results on electric power consumption. According to the management of the JSC “Russian Railways”, electric locomotives EP20, designed for two types of current, have the highest specific energy consumption. These are modern electric locomotives with powerful asynchronous traction motors. Electric locomotives typically operate in passenger traffic. The purpose of the research was to analyze the accounting of energy consumption of passenger electric locomotives in the locomotive operating depots. The article provides results of a comparative statistical analysis of primary materials on the energy consumption of passenger electric locomotives EP20 and other series of electric locomotives such as EP2K DC and EP1M AC. According to the primary materials from the locomotive operational depots, it was found that passenger electric locomotives with trains of double-decker passenger cars have the highest specific energy consumption. Comparison of specific electric power consumption by electric locomotives with single-type passenger cars showed that with DC electric traction, the consumption level of the EP20 significantly exceeds the consumption of the electric locomotives EP2K; with an AC electric traction, the flow rate of the EP20 is almost equal to the specific electric power consumption of the EP1M electric locomotives. A comparative analysis of the load of EP20 electric locomotives during the maintenance of passenger trains allocated for it in the Moscow — Adler section showed that the electric locomotive was underloaded, which causes a decrease in its efficiency and, as a result, over-consumption of electricity. The use of high-power brake resistors will lead to energy consumption, which must be taken into account in the life cycle cost of EP20 electric locomotives.

Rotatable cam-based variable-ratio lever compliant actuator for wearable devices

This paper presents a novel variable stiffness mechanism based on the combination of a rotatable cam and a variable-ratio lever principle. The proposed configuration results in i) a pseudo-linear torque/deflection characteristics, where ii) the stiffness is varied rotationally and perpendicularly to the external load. The first is convenient for easier mechanism dimensioning and offers a more conventional control design. The second allows for a more energy efficient stiffness variation, thereby enabling the use of a less powerful stiffness variation motor and a reduction of the overall actuator weight and size. The presented mathematical model derivation and theoretical evaluation support both desired mechanism characteristics. Practical use of the mechanism is evaluated through the application of the developed prototype in a fully sensorized variable stiffness actuator intended for a wearable application. The results of the experiments and a comparison to other variable stiffness mechanisms show that the mechanism geometry is convenient for light and compact design.

Assessment of different biomass feeding strategies for improving the enzymatic hydrolysis of sugarcane straw

This work describes improvements in the enzymatic hydrolysis of hydrothermally pretreated sugarcane straw. The experiments were performed in batch and fed-batch operation modes (50 mL and 3 L working volumes) with final solid loadings of 10, 20, and 30% (w/v) and enzyme dosage of 10 FPU/gsubstrate. The fed-batch assays showed the most promising results in terms of glucose production and cellulose-to-glucose conversion. In the experiments using a 3 L working volume, analysis of cellulose-to-glucose conversion, power consumption, and apparent viscosity showed that the best assays were those with smoother feed delivery (substrate plus enzyme) throughout the enzymatic hydrolysis. This strategy resulted in 108.8 g/L of glucose and cellulose-to-glucose conversion of 59.7%, corresponding to a final theoretical ethanol content of 55.6 g/L. The power consumption per unit volume and the apparent viscosity were less than 5 kW/m3 and 35 mPa s, respectively, throughout the hydrolysis. Thus, a more concentrated liquor and a less powerful motor to deliver power during the hydrolysis process were obtained in fed-batch strategy reducing the process energy costs.

An entirely enclosed scanning tunnelling microscope capable of being fully immersed in liquid helium.

We present an ultrahigh-vacuum (UHV)-sealed high-stability scanning tunnelling microscope (STM) that can be entirely immersed in liquid helium and readily used in a commercial Dewar or superconducting magnet. The STM head features a horizontal microscanner that can become standalone and ultrastable when the coarse approach inertial motor retracts. Low voltage is enough to operate the STM even at low temperature owing to the powerful motor. It is housed in a tubular chamber of 49 mm outer diameter, which can be pumped via a detachable valve (DV), UHV-sealed and remain sealed after the DV is removed. The entire so-sealed chamber can then be inserted into liquid helium, where in situ sample cleavage is done via vacuum bellow. This allows sample cleavage and STM measurements to take place in better UHV with higher cooling power. Quality atomic resolution images of graphite and charge density wave on 1T-TiSe2 taken in ambient and 14 K conditions, respectively, are presented.

Trends in hydraulic actuators and components in legged and tough robots: a review

Hydraulics is an old technology which is being applied in many applications including large machinery, heavy industries, and early robotics. The traditional features of hydraulics that possess a high power to weight ratio compared to other power transmission system make it suitable to work in a tough and robust environment. However, the trend of hydraulic system has decreased since the introduction and mass usage of the powerful brushless motor and rare earth magnetic motor in industrial sector since the 1980s. Recently, hydraulic systems have shown incremental demand where the innovation of hydraulic actuators and components was actively conducted aimed at compactness, lightweight with higher energy-efficiency, clean and friendly features for many applications in both mobile and industrial hydraulics. This review shows the hydraulic trends in tough robotics applications which focus on legged robots such as humanoid, search and rescue robot and large machinery. New innovations of hydraulic components such as actuators, pump, and other accessories and trends are discussed for future hydraulics in tough robotics applications.

Micro Geared Ultrasonic Motor

We propose a micro geared ultrasonic motor, the smallest set of a micro ultrasonic motor and micro planetary gear. Our micro ultrasonic motor is one of the most powerful motors in one-millimeter-scale motors. The use of a micro planetary gear amplifies the motor torque to several tens of times and the geared motor enables a high torque density that was unachievable by existing miniature motors. The goal of this paper is to analyze the dynamic characteristic of the micro geared ultrasonic motor with a mathematical model and confirm the torque amplification experimentally using a micro planetary gear prototype. To build the microgear components, we employ a micro-injection molding process using metallic glass, a relatively new material, with a low melting temperature. The micro planetary gear assembly with a diameter of 2 mm, a length of 5.9 mm, and a gear ratio of 256 is built and connected to the micro ultrasonic motor. The micro geared ultrasonic motor demonstrates a continuous torque of 0.4 mN $\cdot$ m and a peak torque of 1 mN $\cdot$ m in the load lifting experiments.

Electrical resistivity of additively manufactured AlSi10Mg for use in electric motors

Additive manufacturing (AM) opens up a design freedom beyond the limits of traditional manufacturing techniques. Electrical windings created through AM could lead to more powerful and compact electric motors, but only if the electrical properties of the AM printed part can be shown to be similar to conventionally manufactured systems. Until now, no study has reported on the suitability of AM parts for electrical applications as there are few appropriate materials available to AM for this purpose. AlSi10Mg is a relatively good electrical conductor that does not have the same reported issues associated with processing pure aluminium or copper via selective laser melting (SLM). Here, experiments were conducted to test the effects of geometry and heat treatments on the resistivity of AlSi10Mg processed by SLM. It was found that post heat treatments resulted in a resistivity that was 33% lower than the as-built material. The heat treatment also eliminated variance in the resistivity of as-built parts due to initial build orientation. By conducting these tests, it was found that, with this material, there is no penalty in terms of higher resistivity for using AM in electrical applications, thus allowing more design freedom in future electrical applications.

Bacteriophage N4 large terminase: expression, purification and X-ray crystallographic analysis.

Genome packaging is a critical step in the assembly of dsDNA bacteriophages and is carried out by a powerful molecular motor known as the large terminase. To date, wild-type structures of only two large terminase proteins are available, and more structural information is needed to understand the genome-packaging mechanism. Towards this goal, the large and small terminase proteins from bacteriophage N4, which infects the Escherichia coli K12 strain, have been cloned, expressed and purified. The purified putative large terminase protein hydrolyzes ATP, and this is enhanced in the presence of the small terminase. The large terminase protein was crystallized using the sitting-drop vapour-diffusion method and the crystal diffracted to 2.8 Å resolution using a home X-ray source. Analysis of the X-ray diffraction data showed that the crystal belonged to space group P212121, with unit-cell parameters a = 53.7, b = 93.6, c = 124.9 Å, α = β = γ = 90°. The crystal had a solvent content of 50.2% and contained one molecule in the asymmetric unit.

New design for inertial piezoelectric motors

We have designed, implemented, and tested a novel inertial piezoelectric motor (IPM) that is the first IPM to have controllable total friction force, which means that it sticks with large total friction forces and slips with severely reduced total friction forces. This allows the IPM to work with greater robustness and produce a larger output force at a lower threshold voltage while also providing higher rigidity. This is a new IPM design that means that the total friction force can be dramatically reduced or even canceled where necessary by pushing the clamping points at the ends of a piezoelectric tube that contains the sliding shaft inside it in the opposite directions during piezoelectric deformation. Therefore, when the shaft is propelled forward by another exterior piezoelectric tube, the inner piezoelectric tube can deform to reduce the total friction force acting on the shaft instantly and cause more effective stepping movement of the shaft. While our new IPM requires the addition of another piezoelectric tube, which leads to an increase in volume of 120% when compared with traditional IPMs, the average step size has increased by more than 400% and the threshold voltage has decreased by more than 50 V. The improvement in performance is far more significant than the increase in volume. This enhanced performance will allow the proposed IPM to work under large load conditions where a simple and powerful piezoelectric motor is needed.

RNA End Fluctuations out of a Virus: A Parasite's Fishing ROD for Maximizing Amplification

Viruses are some of the simplest known biological entities and yet their parasitic life cycles offer many intriguing elements for study into how complex biological systems work. A current challenge in biology is to determine how the dynamics of a system can be deduced, and virus disassembly certainly has many challenging dynamics to capture to fully understand its developmental process. There are two main disparate virus genome release strategies. Most double stranded DNA viruses use a pressure-based mechanism to release the genome in a spontaneous fashion, but the process of packaging the DNA into the tight confines of a preformed icosahedral capsid shell requires immense cellular energy and powerful molecular motors. Single-stranded RNA viruses, however, must have work done on them to release their genome, while in contrast to double-stranded DNA viruses, the process of forming single-stranded RNA viruses, via co-self-assembly of its coat protein and RNA genome, is spontaneous. How does a stable self-assembled virus particle release its genome to its host to prime the process of viral replication? Our experiments show that RNA from inside virus like particles formed in vitro can make its 5’ end of the RNA available to probes that cannot enter the virus capsid. Our probing data lends to the hypothesis that RNA viruses like brome mosaic virus may minimally release only an end of its genome to engage the ribosomal machinery of its host cell while the rest of the genome remains protected inside the intact virus capsid. In addition, we posit that the ribosomal machinery is responsible for pulling RNA out of the intact capsid, and use single-molecule methods to measure the force necessary to pull RNA out of an intact capsid.

Lightweight, powerful motor

Lightweight, powerful motor

Altering the speed of a DNA packaging motor from bacteriophage T4.

The speed at which a molecular motor operates is critically important for the survival of a virus or an organism but very little is known about the underlying mechanisms. Tailed bacteriophage T4 employs one of the fastest and most powerful packaging motors, a pentamer of gp17 that translocates DNA at a rate of up to ∼2000-bp/s. We hypothesize, guided by structural and genetic analyses, that a unique hydrophobic environment in the catalytic space of gp17-adenosine triphosphatase (ATPase) determines the rate at which the ‘lytic water’ molecule is activated and OH− nucleophile is generated, in turn determining the speed of the motor. We tested this hypothesis by identifying two hydrophobic amino acids, M195 and F259, in the catalytic space of gp17-ATPase that are in a position to modulate motor speed. Combinatorial mutagenesis demonstrated that hydrophobic substitutions were tolerated but polar or charged substitutions resulted in null or cold-sensitive/small-plaque phenotypes. Quantitative biochemical and single-molecule analyses showed that the mutant motors exhibited 1.8- to 2.5-fold lower rate of ATP hydrolysis, 2.5- to 4.5-fold lower DNA packaging velocity, and required an activator protein, gp16 for rapid firing of ATPases. These studies uncover a speed control mechanism that might allow selection of motors with optimal performance for organisms’ survival.

Real-Time Control Algorithms for a Hybrid Electric Race Car Using a Two-Level Model Predictive Control Scheme

Since 2014, the Formula 1 power unit has consisted of an internal combustion engine equipped with an electrified turbocharger and a powerful electric motor with regenerative braking and boosting capabilities. This hybrid electric powertrain is controlled by a dedicated energy management system, whose decisions significantly influence the achievable lap time, as well as the fuel and electric energy consumption. Therefore, feedback control algorithms must be designed in order to follow lap time optimal strategies and properly react to disturbances. In this paper, we propose a real-time control algorithm based on a two-level model predictive control (MPC) scheme. A high-level controller, based on a convex model of the system, is used to periodically update the optimal strategies, whereas a zone MPC scheme is designed as a linear program to follow these trajectories in an optimal way. Each iteration of the low-level MPC can be calculated within few milliseconds, thus allowing for a suitable update frequency. The optimality of the presented controller is verified using a benchmark simulator, and its performance is finally tested on a third-party high-fidelity nonlinear simulator of the race car.

Simulating the transients in a load node with a triple-wound transformer at different voltage levels

The transient processes in the load node of a power system, which contains powerful induction motors and triple-wound transformers, are simulated. A technique for transient calculation using direct-current synthetic schemes of electric circuits (Dommel’s algorithm) is presented. A dynamic model of an induction motor in the phase domain and a model of a triple-wound transformer based on inductively coupled branches are used taking into account the transformation of voltage levels. It is shown that the mutual influence of different voltage levels in the circuits can be investigated in the phase domain, within one model, and in the course of one simulation process. As an example, we consider a 110/35/10-kV load node that contains an induction motor, a static load, and a reactive power-compensation device in the form of a capacitor on the low-voltage side, as well as power-transmission lines on the medium-voltage side. Dommel’s algorithm makes it possible to investigate various types of nonlinear elements in the system and does not impose any restrictions on the waveform and harmonic composition of signals in the model. The algorithm also allows one to change the parameters and configuration of the timing constraints, which increases the range of the modes considered. When simulating the load node in this domain, various types of asymmetry and complex faults can be considered. The model of the induction motor is highly flexible and yields good results when calculating the dynamic modes.

Quantum chemical design of rotary molecular motors

AbstractThis tutorial review describes how recent quantum chemical calculations and non‐adiabatic molecular dynamics simulations have provided valuable guidelines and insights for the design of more powerful synthetic rotary molecular motors. Following a brief overview of the various types of rotary motors synthesized to date, we present computationally identified steric and electronic approaches to significantly reduce the free‐energy barriers of the critical thermal isomerization steps of chiral overcrowded alkenes, a main class of motors whose potential for many different kinds of applications is well documented. Furthermore, we describe how computational research in this field has provided new motor designs that differ from overcrowded alkenes by either (1) completing a full 360° rotation through fewer steps, (2) exhibiting more efficient photochemical steps, or (3) requiring fewer chiral features for their function, including a design that even in the absence of a stereocenter achieves unidirectional rotary motion from two Z/E photoisomerizations alone.

Resource-saving protection of powerful electric motors

Resource-saving protection of powerful electric motors

THE STRUCTURAL BASIS FOR POLYPEPTIDE TRANSLOCATION BY THE HSP104 DISAGGREGASE

Heat shock protein (Hsp) 104, found in yeast, is a member of the Hsp100 class of molecular chaperones that contain highly conserved AAA+ (ATPases Associated with diverse cellular Activities) domains and serve critical roles in thermotolerance and protein quality control. Hsp104, and the bacterial homolog ClpB, form large hexameric‐ring structures that cooperate with the Hsp70 system to unfold and rescue aggregated protein states by active translocation of polypeptide substrates through a central channel. Hsp104 controls prion inheritance in yeast by recognizing and remodeling cross‐β structures of amyloid fibrils, such as those found in Sup35 prions. This function has led to studies identifying potentiated Hsp104 variants that reduce the toxicity of proteins linked to neurodegenerative diseases. Despite fundamental roles in protein quality control and promising therapeutic activity in rescuing amyloidogenic states, how Hsp104 and its family members function as powerful molecular motors to solubilize proteins is not fully understood. Furthermore, obtaining high‐resolution views of active complexes has been a significant challenge, thus a definitive structural mechanism for disaggregation has remained elusive. Here we have determined the cryo‐EM structure of wild type Hsp104 in the ATP state to 5.6 Å resolution. This work reveals an unprecedented two‐turn spiral architecture for the hexamer, identifying how the twelve AAA+ domains are coordinated for substrate translocation. The N‐terminal, C‐terminal and middle domains are observed in distinct conformations that explain functions in substrate engagement and ATP hydrolysis control. Remarkably, density for the substrate‐binding pore loops is identified to line the channel in a continuous arrangement that appears optimized for substrate transfer across the AAA+ domains, establishing a directional path for polypeptide translocation.Support or Funding InformationThis work was supported by National Institutes of Health (NIH) grant R01GM099836 (to J.S.). A.L.Y. is supported by an American Heart Association Predoctoral fellowship; M.E.J. is supported by a Target ALS Springboard Fellowship. J.S. is supported by a Muscular Dystrophy Association Research Award (MDA277268), the Life Extension Foundation, the Packard Center for ALS Research at Johns Hopkins University, and Target ALS. D.R.S. is supported by NIH grants R01GM109896, R01GM077430 and R01GM110001A.

Miniature preload mechanisms for a micro ultrasonic motor

We propose the smallest preload generation mechanisms that provide force between the rotor and the one cubic millimeter stator in a micro ultrasonic motor. Miniaturizing the preload mechanism is key for implementation of a micro ultrasonic motor with the best performance into micro devices. In this paper, we evaluate two kinds of preloads that exert in the axial and radial directions: an axial preload mechanism and a radial preload mechanism. The experiments clarify how both preload mechanisms improve motor performance measures such as angular velocity, torque, and efficiency. The micro ultrasonic motors with both preload mechanisms generated torque over 10μNm at the experimentally optimized preload of approximately 6g. By designing the miniature preload mechanisms using a micro coil spring, the preload mechanisms are miniaturized with similar motor performance. At present, they represent the smallest and most powerful ultrasonic motors with preload mechanisms.