High-torque Motor Research Articles

Molecular model of a bacterial flagellar motor in situ reveals a "parts-list" of protein adaptations to increase torque.

One hurdle to understanding how molecular machines work, and how they evolve, is our inability to see their structures in situ . Here we describe a minicell system that enables in situ cryogenic electron microscopy imaging and single particle analysis to investigate the structure of an iconic molecular machine, the bacterial flagellar motor, which spins a helical propeller for propulsion. We determine the structure of the high-torque Campylobacter jejuni motor in situ, including the subnanometre-resolution structure of the periplasmic scaffold, an adaptation essential to high torque. Our structure enables identification of new proteins, and interpretation with molecular models highlights origins of new components, reveals modifications of the conserved motor core, and explain how these structures both template a wider ring of motor proteins, and buttress the motor during swimming reversals. We also acquire insights into universal principles of flagellar torque generation. This approach is broadly applicable to other membrane-residing bacterial molecular machines complexes.

Research on efficient design method of high torque motor with dual airgap hybrid rotor for aircraft engines

AbstractHigh torque density and high reliability motors have a wide application prospect in aerospace field, so a hybrid rotor and dual stator motor is studied in this paper. Firstly, to address the problem that the difference in power density between the inner and outer unit motor is so large that it is not suitable for electromagnetic design using the power splitting method, a main dimensioning calculation method based on the equal‐power volume transformation is proposed. The influence of thermal load on the output performance of the inner and outer unit motors is taken into account comprehensively. The main dimensioning expressions for such motors are derived. Secondly, the output performance consistency between the inner and outer unit motors is theoretically analysed, and the optimal angle between the d‐axis of the permanent magnet rotor and the d‐axis of the reluctance rotor is obtained when the motor is operated in the maximum torque per ampere control mode. Finally, a prototype with a rated power of 46.7 kW was developed and load experiments were conducted on it, and the experimental results verified the correctness and feasibility of the theoretical analysis method.

An Investigation into the Pole–Slot Ratio and Optimization of a Low-Speed and High-Torque Permanent Magnet Motor

At present, low-speed high-torque permanent magnet motors are widely used in the sampling industry, manufacturing industry and energy industry. However, the research on low-speed high-torque permanent magnet motors is far from enough. The primary difficulty in the initial design of low-speed high-torque permanent magnet motors is the selection of pole–slot ratio. The pole–slot ratio has a great influence on the electromagnetic performance such as torque ripple and the maximum output torque of low-speed motors. Choosing the appropriate pole–slot ratio scheme can make the design of a low-speed motor more efficient. In addition, the optimization design of the motor is also a necessary process. At present, there are many studies on optimization algorithms. However, the research on sample point sampling and surrogate model fitting is not enough. Choosing the appropriate sample point sampling method and surrogate model fitting method can help one obtain a more accurate surrogate model, which lays a foundation for the optimization of the motor. Based on the above analysis, this paper first selects four representative pole–slot ratio schemes for comprehensive comparison of their electromagnetic performances. Secondly, two sample point sampling methods and three surrogate model fitting methods are combined to obtain six surrogate models, and the accuracy of the six surrogate models is compared and analyzed. Finally, a 37kW,160rpm prototype is made, and the comparison of the surrogate model optimization prediction results, the finite element simulation calculation results and the measured results is carried out to further prove the accuracy of the selected surrogate model. The work performed in this paper provides a certain reference value for the initial design and optimization experiment design of low-speed high-torque permanent magnet motor.

ANALYSIS OF THE POSSIBILITY OF APPLICATION OF HYDRAULIC MOTOR-WHEELS IN TRANSMISSIONS HIGH-SPEED TRACTORS

Goal. The purpose of the article is to assess the possibility of developing a hydraulic fluid power in accordance with the standard traction-speed characteristics of the KhTZ-17021 wheeled tractor with the of using gearless drives of the driving wheels. For this purpose, the calculation of the hydraulic fluid power of the wheeled tractor was performed when using the latest radial piston multi-cycle hydraulic motor-wheels with a wide range of rotation frequency and adjustment of the working volume. Research methodology. An analysis of the traction-speed characteristics of the KhTZ- 17021 wheeled tractor and, based on it, a review of modern high-torque radial-piston multi-cycle hydraulic motors from the point of view of meeting the characteristics of torque and rotation frequency with power limitations relative to the serial model in the full speed range of the tractor. The maximum values of the working volumes of the 4 driving hydraulic motor-wheels and the power supply pump of these hydraulic motors, the torque and pressure drop in the hydraulic drive are calculated, and the modes in which it is necessary to change the working volume of the hydraulic motors from the maximum to the minimum values to work out the traction-speed characteristics. A comparative analysis of radial-piston multi-cycle hydraulic motors was carried out, and for the hydromotor-wheel model MHP27 of the "Poclain Hydraulics" company, which was chosen for the study, the hydraulic principle diagrams were considered with the use of a hydraulic regulation system of four stages of the working volume in hydraulic motors, the use of combined parking and service brakes, as well as an anti-skid system using means of proportional electro-hydraulic automation. The results. High-torque hydraulic motor-wheels of the radial piston type were selected, which make it possible to ensure the operation of the tractor transmission without intermediate gearboxes between the hydraulic motors and wheel hubs, and the calculated value of the working volume of the axial piston pump, which ensures the operation of the tractor transmission in the full speed range. Based on the results of the calculations, it was established that the pressure in the hydraulic drive does not exceed 35 MPa, while values from 40 MPa to 50 MPa are achieved in modern pumps and hydraulic motors. The possibility of increasing the speed of the tractor from standard 35 km/h to promising 50 km/h is shown.

Open continuum robotics-one actuation module to create them all.

Experiments on physical continuum robot are the gold standard for evaluations. Currently, as no commercial continuum robot platform is available, a large variety of early-stage prototypes exists. These prototypes are developed by individual research groups and are often used for a single publication. Thus, a significant amount of time is devoted to creating proprietary hardware and software hindering the development of a common platform, and shifting away scarce time and efforts from the main research challenges. We address this problem by proposing an open-source actuation module, which can be used to build different types of continuum robots. It consists of a high-torque brushless electric motor, a high resolution optical encoder, and a low-gear-ratio transmission. For this article, we create three different types of continuum robots. In addition, we illustrate, for the first time, that continuum robots built with our actuation module can proprioceptively detect external forces. Consequently, our approach opens untapped and under-investigated research directions related to the dynamics and advanced control of continuum robots, where sensing the generalized flow and effort is mandatory. Besides that, we democratize continuum robots research by providing open-source software and hardware with our initiative called the Open Continuum Robotics Project, to increase the accessibility and reproducibility of advanced methods.

A resistance torque compensation algorithm based on Luenberger observer for minimally invasive surgical robot

PurposeThe patient-side manipulator (PSM) achieves high torque capability by combining harmonic servo system with high reduction ratio and low torque motor. However, high reduction ratio can increase inertia and decrease compliance of the manipulator. To enhance the backdrivability of the minimally invasive surgical robot, this paper aims to propose a resistance torque compensation algorithm.Design/methodology/approachA resistance torque compensation algorithm based on dynamics and Luenberger observer is proposed. The dynamics are established, considering joint flexibility and an improved Stribeck friction model. The dynamic parameters are experimentally identified by using the least squares method. With the advantages of clear structure, simple implementation and fast solution speed, the Luenberger observer is selected to estimate the unmeasured dynamic information of PSM and realize the resistance torque compensation.FindingsFor low-speed surgical robots, the centrifugal force term in the dynamic model can be simplified to reduce computational complexity. Joint flexibility and an improved Stribeck friction model can be considered to improve the accuracy of the dynamic model. Experiment results show that parameter identification and estimated results of the Luenberger observer are accurate. The backdrivability of the PSM is enhanced in ease and smoothness.Originality/valueThis algorithm provides potential application prospects for surgical robots to maintain high torque while remaining compliant. Meanwhile, the enhanced backdrivability of the manipulator helps to improve the safety of the preoperative manual adjustment.

Vibration and Noise Analysis of Low-speed High-torque Permanent Magnet Motor for Forging Equipment Based on PSO

Vibration and Noise Analysis of Low-speed High-torque Permanent Magnet Motor for Forging Equipment Based on PSO

MODELLING AND DESIGNING OF E BIKE USING SOLAR PANLES

The rider of an E-bike has the option to rely solely on the motor, pedal while using the motor simultaneously, or pedal only, akin to a conventional bicycle. It's essential that the installation of photovoltaic (P.V.) panels on the electric bicycle does not compromise riding comfort. The idea behind solar energy integration is to equip the bicycle with a high-torque motor powered by solar energy absorbed through portable solar panels. This energy can directly power the motor if it meets requirements; otherwise, a battery serves as backup. During periods of inactivity, such as daytime, the solar panel charges the battery, enhancing the bike's efficiency. This is where electric bicycles shine, offering a green, health-conscious, and swift mode of transportation. Beyond these benefits, electric bicycles can even generate electric power through regenerative pedal power mode. The versatility of an Electric Bicycle extends to various uses. Our goal is to create an Electric Bicycle available at the most affordable rate compared to market prices.

Evolution of friction couples in volume hydraulic machines due to achievements in material science and technology

The article analyses modern achievements in the field of volumetric axial and radial piston hydraulic machines for the mobile sector of application in terms of using the latest design solutions, friction pair materials and technologies. Goal. The aim is to acquaint specialists with directions for creating hydraulic machines of a modern technical level due to increased pressure and rotation frequency. Methodology. The evolution of constructive decisions regarding the selection of pairs of rolling and sliding friction and their change depending on the achievements in materials science, tribology and increasing the accuracy of machines for the finishing of friction surfaces are consistently considered. Results. It is shown that in axial-piston hydraulic machines with an inclined disk, the transition to hydrostatic piston pairs with heel pads was made, which made it possible to increase the pressure up to 52 MPa. In radial-piston high-torque multi-cycle hydraulic motors, almost all manufacturers have replaced the rolling friction piston pairs with sliding pairs due to the latest anti-friction materials and precision processing. Thus, the ratio of mass to power decreased almost 6 times. For radial-piston hydraulic transmissions with ball-pistons, a failure analysis was performed, respectively, regarding the materials used, quality and control of heat treatment. Originality and practical value. For promising high-speed hydraulic transmissions with ball-pistons, recommendations have been developed for the selection of steels and control of their manufacture on the basis of taking into account materials science tools. The work in the production of piston balls from ceramic materials are offered. The given informative and practical research results are planned to be taught to master's students in the discipline of "Design and Testing of Hydraulic Drives of Construction and Road Vehicles" at KhNAHU.

Novel Magnetic Field Modeling Method for a Low-Speed, High-Torque External-Rotor Permanent-Magnet Synchronous Motor

In view of the unstable electromagnetic performance of the air gap magnetic field caused by the torque ripple and harmonic interference of a multi-slot and multi-pole low-speed, high-torque permanent magnet synchronous motor, we propose a simplified model of double-layer permanent magnets. The model is divided into an upper and a lower subdomain, with the upper subdomain being an ideal circular ring and the lower subdomain being a segmented sector ring. Moreover, we develop an exact analytical model of the motor that predicts the magnetic field distribution based on Laplace’s and Poisson’s equations, which is solved using the method of separating variables. Taking a 40p168s low-speed, high-torque permanent magnet synchronous motor as an example, the accuracy of the model is verified by comparison with an ideal circular ring model, a segmented sector ring model, and the finite element method. Based on the proposed simplified model, three combined permanent magnets considering both edge-cutting and polar arc cutting structures are proposed, which are chamfered, rounded, and rectangular combinations. Under the premise of a consistent edge-cutting amount, the electromagnetic characteristics of the three combination types of permanent magnets are compared using the finite element method. The results show that the electromagnetic characteristics of the chamfered combination PM are superior to those of the other two combinations. Finally, a prototype is manufactured and tested to validate the theoretical analysis.

Realization of combined dynamic motion mode for roller forming unit

The combined dynamic mode of the reciprocating motion for a forming trolley is calculated to increase the reliability and durability of the roller forming unit. The criterion action is used as a criterion of the motion mode, which is an integral over time with the sub-integral function that expresses the acceleration «energy» when calculating the combined dynamic motion mode of the forming trolley in the acceleration and braking areas. The change functions of the kinematic characteristics of the forming trolley during its motion from one extreme position to another, which correspond to the combined dynamic mode of the reciprocating motion, are calculated. The displacement and speed of the forming trolley in the acceleration and braking areas change smoothly with this motion mode, without creating significant dynamic loads in the unit, which in turn has a positive effect on its durability.
 The variation law of the compaction rollers angular velocity is calculated by taking into account the change functions of the forming trolley speed. The roller forming unit design with a drive from the high-torque stepper motor is proposed, which is mounted in the compaction rollers of the forming trolley and provides the combined dynamic mode of reciprocating motion for the forming trolley. The surface quality of the processed concrete mixture is increased, dynamic loads in the drive mechanism elements are reduced, unnecessary destructive loads on the frame construction are disappeared and, accordingly, the reliability and durability of the unit as a whole are increased, when we use the such drive in the unit.

Analysis of the technical level of hydraulic fluid power with motor-wheels

The analysis of the use of hydraulic fluid power of rotation of hydraulic motor-wheels for tracked and wheeled machines was carried out. The hydraulic principle schemes for the use of high-speed axial-piston hydraulic motors with planetary gearboxes and high-torque low-speed radial-piston hydraulic motors are considered, in particular, hydraulic devices for ensuring reliable movement in the event of obstacles from the road surface. The features of static and dynamic calculation methods using a mathematical model for the numerical solution of differential equations when calculating pressure fluctuations and the frequency of rotation of hydraulic motors depending on the tasks of changing the intensity of the pump supply and the working volume of the hydraulic motor, taking into account its efficiency, are shown. A comparative analysis of the technical level of hydraulic motor-wheels was carried out and a significant increase in the output parameters of high-torque radial piston hydraulic motors with respect to pressure, rotation frequency and mass-to-torque ratio was revealed. The article may be useful for engineers, scientists and master's students.

AI Based Grass Cutting Rover Using Image Processing to Move the Obstacle

In today's technologies, automation is expanding quickly. Therefore, Automation is essential in the agriculture sector and beneficial to farmers. Grass cutters were manually operated portable instruments in former times. As a result, they used gas and petrol engines, which resulted in pollution and energy loss. Therefore, it is necessary to replace the old grass cutters with automated ones that use batteries as a power source for the system's guiding and obstacle detection. Additionally, It utilized a motor drive for the robot's wheels, a linear blade to cut the grass and using image processor for object detection, and an arm at the front of the rover to move the small obstacles which can protect the grass cutting blade and an Arduino UNO microcontroller board as the system's primary controller. A cordless electric lawn mower, which is self-powered by electricity, is another goal of the project. A Raspberry Pi microprocessor serves as the machine's brain and directs the movements of the lawnmower. It is made up of geared motors that manage the mover's speed and direction.and a high-torque motor that drives the cutting blades. The geared motors are switched on and off using a control circuit that is comprised of MOSFETS that are controlled by the raspberry pi. The mover has an onboard camera which is used by the microprocessor to detect objects and living beings and take the necessary action that being, to avoid themorstop moving. It is completely automated and renewable.

Analyzing the possibility of using hiqhtorque hydraulic motors for rotation of the drums of automatic concrete mixers

Goal. The goal is conducting an analysis of the use of hydraulic fluid power for rotating the drums of concrete mixers, in particular, evaluating the possibility of using high-torque low-speed radial-piston hydraulic motors instead of axial-piston motors with planetary gearboxes. The technical level of such hydraulic drives is assessed based on the use of mass to torque and power ratios. The nomenclature, technical characteristics and design features of high-torque hydraulic motors are considered. In particular, compared to previous studies, the nomenclature of the considered hydraulic motors is widespread. Method. The methods of comparative analysis of designs and technical characteristics of axial-piston with planetary gearboxes and high-torque hydraulic motors according to the main technical parameters, in particular, the developing pressure, torque, rotation frequency and power depending on the specific indicators of the mass ratio to the absolute values of these parameters were used. Design features of high-torque hydraulic motors were also considered. Originality. For the first time in the domestic literature, a comparative analysis of the performed high -motion hydraulic motors of the MCR model was carried out. Results and practical usefulness. It is recognized that the modern technical level of high-torque hydraulic motors allows to compete with axial-piston gear hydraulic drives for rotating drums with a concrete mixture of auto-concrete mixers. The given materials will be useful in the educational process for machine-building specialists who study hydraulic fluid power as a means of improving the technical level of various machines and mechanisms.

Development of a Proprioceptive Neuromuscular Facilitation Stretching System Using a Low-Speed, High-Torque Motor

Development of a Proprioceptive Neuromuscular Facilitation Stretching System Using a Low-Speed, High-Torque Motor

ANALYSIS OF TECHNICAL CHARACTERISTICS OF HIGH TORQUE HYDROMOTORS WITH LIMITATIONS BASED ON DYNAMIC CALCULATIONS

The goal is to study the technical characteristics of the world's largest modern high-torque multi-acting hydraulic motor from the point of view of ensuring reliable operation by the manufacturer at elevated pressures, speeds and depending on the type of working fluid used. Analysis of the influence of dynamic loads on fluctuations in pressure and speed of the hydraulic motor in the modes of starting and braking, taking into account changes in the pump flow rate and inertial loads. Method. Dynamic calculation of a hydraulic fluid power with a high-torque hydraulic motor based on studies of external loads, changes in the pump feed time, providing the maximum speed. To solve nonlinear differential equations when calculating the pressure in the hydraulic drive and the rotational speed of the hydraulic motor, the VisSim application software package was used. The modes of change in the operation of the hydraulic motor over time in terms of rotational speed, pressure in the hydraulic fluid power, output power and hydromechanical efficiency, depending on the external load and pump flow, are presented on the corresponding oscillograms. The mathematical model of the hydraulic fluid power includes simulation modules for controlling the supply of an axial piston pump and changing the moment of resistance on the hydraulic motor. Results. Calculations of the dynamics of a hydraulic fluid power with a high-torque multi-acting radial piston hydraulic motor showed the need for preliminary modeling of its operation modes, taking into account the nature of the external loading, the moment of inertia and the intensity of the pump flow. Conclusion. The conducted studies can be used in the development of hydraulic fluid power with high-torque hydraulic motors to clarify the technological processes of work during the operation of a hydraulic machine.

Remotely Controlled Electronic Goalkeeper: An Example of Improving Social Integration of Persons with and without Disabilities

Social integration is an essential part of the life of every human being, but for people with disabilities, there are many situations in which it is still very low. For instance, in sports and outdoor gaming, there is a barrier between players with and without disabilities. Individuals with disabilities play sports almost exclusively with disabled players, not only during official events such as Paralympic games but also in occasional sports groups, while the mixing of people with and without disabilities in sports activities is a key factor of social inclusion. In order to allow a person with motor-skill impairments to play on the same ground as their non-disabled peers, we developed a novel piece of Assistive Technology that lets a person with motor-skill impairments to control a system acting as a goalkeeper during a non-professional football match, with approximately the same performances as a goalkeeper without motor-skill impairments. This electro-mechanical system is composed of a three-meter-long metal guideline and a human-shaped dummy sliding along it. The system is equipped with a high-torque battery-powered direct-current motor and it is controlled by means of electronic boards and sensors to ensure safety and good usability also for players with severe mobility impairments. The results of a pilot testing demonstrated the robustness and high degree of usability of the system, enabling people with motor-skill impairments to competitively participate in matches with non-disabled peers.

Soft Robotics: An Introduction to the Special Issue

Soft robotics is a new and fast-growing field of robotics <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> , <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> . It proposes to extend conventional robotics by going beyond the default building blocks, that is, rigid body parts and high-torque servo motors. Soft robotics also uses soft materials like silicone, hydrogels, and polymers. It also includes a wide range of smart materials that are able to change physical properties when stimulated, therefore outsourcing computational functionality directly to the body of the robot (this concept is often referred to as morphological computation <xref ref-type="bibr" rid="ref3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[3]</xref> , <xref ref-type="bibr" rid="ref4" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[4]</xref> ). In addition, soft robotics considers partially rigid structures like tensegrity designs, foldable robots, origami-based mechanisms, and many others <xref ref-type="bibr" rid="ref5" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[5]</xref> . This expansion of the design space enriches robotics in general and opens the space for radically novel sensing and actuation systems and, consequently, for new applications that were previously out of reach for conventional robotic systems.

Leveraging Morphological Computation for Controlling Soft Robots: Learning from Nature to Control Soft Robots

Traditional robot designs typically employ rigid body parts and high-torque servo motors. This helps to obtain simple reproducible models and, therefore, to facilitate control. Soft robotics is a new research field that deliberately expands the design toolbox to a wide range of smart and, often, soft materials. This approach is generally inspired by the remarkable performance of biological systems, which use soft structures to interact successfully with noisy and hard-to-model environments and, as a result, outperform state-of-the-art robots in open-world scenarios. However, using soft bodies comes with a significant disadvantage. Soft materials often have complex and nonlinear dynamics, which makes them hard to model and therefore difficult to control. To fulfill the potential of soft robotics to achieve performances close to biological systems, this control problem has to be solved. A promising solution is another bioinspired principle called morphological computation, which proposes to outsource functionality directly to the body morphology. From this point of view, the seemingly undesired nonlinear dynamics become a resource for implementing nonlinear functionalities. This extends the control design problem to the question of how to design the body morphology of the robot. While there exist proofs of concept that demonstrate the potential of this approach, the existing work (for the most part) is lacking mathematical rigor and a general framework. We believe that the control community has the right set of tools to support the development of a design framework for morphological computation. The goal of this article (see “Summary”) is to provide an introduction to the concepts of soft robotics and morphological computation, explain how they can work together, and (with the help of examples) illustrate their potential for control. The hope is to inspire members of the control community to develop novel control frameworks for the next generation of soft robots.

Torque Ripple Reduction of PMSM Based on Modified DBN-DNN Surrogate Model

Due to the nonlinearity and dead time of the inverter, a great number of harmonic components is introduced into the motor input current, causing the torque ripple of the motor. The paper aims to suppress the torque ripple of a low-speed and high-torque permanent magnet synchronous motor (PMSM) with a two-step stator voltage optimization method, including a high precision harmonic voltage injection (HPHVC) method and a deep belief network (DBN)-deep neural network (DNN) voltage prediction model. Firstly, a closed-loop harmonic current detection system with Type-II Chebyshev filter is adopted to enhance the harmonic current extraction accuracy. Secondly, a harmonic voltage algorithm is designed considering the dq-axis current coupling relationship, which improves the accuracy of harmonic voltage calculation. Thirdly, a dq-axis voltage prediction model is constructed using DBN-DNN algorithm as the surrogate model, which further reduces the current harmonic components caused by the harmonic injection structure and the PI control algorithm, reduces the torque pulsation of the motor, and boosts the dynamic performance of the motor. Finally, the experimental platform is constructed by embedding the proposed strategy into the field oriented control system for reducing the torque pulsation. The experimental results verify the proposed strategy.