The Experts below are selected from a list of 2358 Experts worldwide ranked by ideXlab platform
Kurt Stockman - One of the best experts on this subject based on the ideXlab platform.
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sensorless load angle control for two phase hybrid stepper Motors
Mechatronics, 2017Co-Authors: Stijn Derammelaere, Jasper De Viaene, Bram Vervisch, Kurt StockmanAbstract:Abstract The widely used full-step open-loop Stepping motor drive algorithms are characterised by a low torque/power ratio, large torque ripple and resonance problems. In order to use Stepping Motors in more demanding applications, closed-loop control is needed. In this paper, a previously described load angle estimation algorithm, solely based on voltage and current measurements, is used to provide the necessary feedback without using a mechanical position sensor. This paper introduces a novel closed-loop load angle controller which optimises the current level based on the estimated load angle. This approach is challenging as the current - load angle dynamics are highly nonlinear. However, in this research a linear model is proposed and used to tune a PI load angle controller. The controller reduces the current level to obtain the optimal load angle but does not change the way Stepping-motor are driven by step command pulses. This results in a broad industrial employability of these algorithms. The proposed sensorless controller is validated trough both simulations and measurements.
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A quantitative comparison between BLDC, PMSM, brushed DC and Stepping motor technologies
2016Co-Authors: Stijn Derammelaere, Michiel Haemers, Jasper De Viaene, Florian Verbelen, Kurt StockmanAbstract:Brushless DC machines (BLDC), Permanent Magnet Synchronous Machines (PMSM), Stepping Motors and Brushed DC machines (BDC) usage is ubiquitous in the power range below 1,5kW. There is a lot of common knowledge on these technologies. Stepping Motors are ideally suited for open loop positioning, BLDC machines are the most obvious candidate for high-speed applications, etc. However, literature lacks comprehensive research comparing these machines over a large range of applications. In this paper, more than 100 Motors are considered. Their characteristics are compared and presented in a comprehensive way. These results support the common knowledge concerning the field of application of each technology and new insights follow from this quantitative comparison.
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Torque ripples in Stepping motor driven systems
2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015Co-Authors: Stijn Derammelaere, Florian Verbelen, Bram Vervisch, Kurt StockmanAbstract:Stepping motor operation is characterized by torque ripples. In this paper it is shown these torque ripples are caused by both the Stepping motor drive algorithms and the toothed construction of rotor and stator of the studied hybrid Stepping Motors. These torque ripples are analyzed, discussed and measured. The torque ripples are measured in the complete operating range of the motor and depicted in this paper for full- half- and micro-Stepping. By doing this, the paper provides insight in the vibrating behavior of a Stepping motor driven system and possible solutions to overcome this are placed in the right perspective.
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open loop control of a Stepping motor with step loss detection and stall detection using back emf based load angle estimation
International Conference on Advanced Intelligent Mechatronics, 2014Co-Authors: Stijn Derammelaere, Florian Verbelen, Kurt StockmanAbstract:Stepping Motors are the most used electrical machines for low power positioning. The drive controls the machine so that the rotor performs a fixed angular displacement after each step command pulse. Counting the step command pulses enables open-loop positioning. The vast majority of the Stepping motor systems is driven in open-loop. When the rotor hits an obstacle stall occurs. Step loss due to overload is another typical problem with Stepping motor driven systems. Both phenomena are not detected in open-loop which causes loss of synchronism. In this paper, a sensorless load angle estimator is used to detect step loss and stall. This algorithm is based on the typical Stepping motor drive algorithms and does not depend on mechanical load parameters. The method therefore has a broad industrial relevance.
Wolfgang Junge - One of the best experts on this subject based on the ideXlab platform.
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two rotary Motors in f atp synthase are elastically coupled by a flexible rotor and a stiff stator stalk
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Andre Wachter, Hendrik Sielaff, Stanley D Dunn, Siegfried Engelbrecht, Yumin Bi, Brian D Cain, Frank Wintermann, Wolfgang JungeAbstract:ATP is synthesized by ATP synthase (FOF1-ATPase). Its rotary electromotor (FO) translocates protons (in some organisms sodium cations) and generates torque to drive the rotary chemical generator (F1). Elastic power transmission between FO and F1 is essential for smoothing the cooperation of these Stepping Motors, thereby increasing their kinetic efficiency. A particularly compliant elastic domain is located on the central rotor (c10–15/ϵ/γ), right between the two sites of torque generation and consumption. The hinge on the active lever on subunit β adds further compliance. It is under contention whether or not the peripheral stalk (and the “stator” as a whole) also serves as elastic buffer. In the enzyme from Escherichia coli, the most extended component of the stalk is the homodimer b2, a right-handed α-helical coiled coil. By fluctuation analysis we determined the spring constant of the stator in response to twisting and bending, and compared wild-type with b-mutant enzymes. In both deformation modes, the stator was very stiff in the wild type. It was more compliant if b was elongated by 11 amino acid residues. Substitution of three consecutive residues in b by glycine, expected to destabilize its α-helical structure, further reduced the stiffness against bending deformation. In any case, the stator was at least 10-fold stiffer than the rotor, and the enzyme retained its proton-coupled activity.
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domain compliance and elastic power transmission in rotary f o f 1 atpase
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Hendrik Sielaff, Henning Rennekamp, Andre Wachter, Hao Xie, Florian Hilbers, Katrin Feldbauer, Stanley D Dunn, Siegfried Engelbrecht, Wolfgang JungeAbstract:The 2 nanoMotors of rotary ATP synthase, ionmotive FO and chemically active F1, are mechanically coupled by a central rotor and an eccentric bearing. Both Motors rotate, with 3 steps in F1 and 10–15 in FO. Simulation by statistical mechanics has revealed that an elastic power transmission is required for a high rate of coupled turnover. Here, we investigate the distribution in the FOF1 structure of compliant and stiff domains. The compliance of certain domains was restricted by engineered disulfide bridges between rotor and stator, and the torsional stiffness (κ) of unrestricted domains was determined by analyzing their thermal rotary fluctuations. A fluorescent magnetic bead was attached to single molecules of F1 and a fluorescent actin filament to FOF1, respectively. They served to probe first the functional rotation and, after formation of the given disulfide bridge, the stochastic rotational motion. Most parts of the enzyme, in particular the central shaft in F1, and the long eccentric bearing were rather stiff (torsional stiffness κ > 750 pNnm). One domain of the rotor, namely where the globular portions of subunits γ and e of F1 contact the c-ring of FO, was more compliant (κ ≅ 68 pNnm). This elastic buffer smoothes the cooperation of the 2 Stepping Motors. It is located were needed, between the 2 sites where the power strokes in FO and F1 are generated and consumed.
Stijn Derammelaere - One of the best experts on this subject based on the ideXlab platform.
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sensorless load angle control for two phase hybrid stepper Motors
Mechatronics, 2017Co-Authors: Stijn Derammelaere, Jasper De Viaene, Bram Vervisch, Kurt StockmanAbstract:Abstract The widely used full-step open-loop Stepping motor drive algorithms are characterised by a low torque/power ratio, large torque ripple and resonance problems. In order to use Stepping Motors in more demanding applications, closed-loop control is needed. In this paper, a previously described load angle estimation algorithm, solely based on voltage and current measurements, is used to provide the necessary feedback without using a mechanical position sensor. This paper introduces a novel closed-loop load angle controller which optimises the current level based on the estimated load angle. This approach is challenging as the current - load angle dynamics are highly nonlinear. However, in this research a linear model is proposed and used to tune a PI load angle controller. The controller reduces the current level to obtain the optimal load angle but does not change the way Stepping-motor are driven by step command pulses. This results in a broad industrial employability of these algorithms. The proposed sensorless controller is validated trough both simulations and measurements.
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A quantitative comparison between BLDC, PMSM, brushed DC and Stepping motor technologies
2016Co-Authors: Stijn Derammelaere, Michiel Haemers, Jasper De Viaene, Florian Verbelen, Kurt StockmanAbstract:Brushless DC machines (BLDC), Permanent Magnet Synchronous Machines (PMSM), Stepping Motors and Brushed DC machines (BDC) usage is ubiquitous in the power range below 1,5kW. There is a lot of common knowledge on these technologies. Stepping Motors are ideally suited for open loop positioning, BLDC machines are the most obvious candidate for high-speed applications, etc. However, literature lacks comprehensive research comparing these machines over a large range of applications. In this paper, more than 100 Motors are considered. Their characteristics are compared and presented in a comprehensive way. These results support the common knowledge concerning the field of application of each technology and new insights follow from this quantitative comparison.
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Torque ripples in Stepping motor driven systems
2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015Co-Authors: Stijn Derammelaere, Florian Verbelen, Bram Vervisch, Kurt StockmanAbstract:Stepping motor operation is characterized by torque ripples. In this paper it is shown these torque ripples are caused by both the Stepping motor drive algorithms and the toothed construction of rotor and stator of the studied hybrid Stepping Motors. These torque ripples are analyzed, discussed and measured. The torque ripples are measured in the complete operating range of the motor and depicted in this paper for full- half- and micro-Stepping. By doing this, the paper provides insight in the vibrating behavior of a Stepping motor driven system and possible solutions to overcome this are placed in the right perspective.
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open loop control of a Stepping motor with step loss detection and stall detection using back emf based load angle estimation
International Conference on Advanced Intelligent Mechatronics, 2014Co-Authors: Stijn Derammelaere, Florian Verbelen, Kurt StockmanAbstract:Stepping Motors are the most used electrical machines for low power positioning. The drive controls the machine so that the rotor performs a fixed angular displacement after each step command pulse. Counting the step command pulses enables open-loop positioning. The vast majority of the Stepping motor systems is driven in open-loop. When the rotor hits an obstacle stall occurs. Step loss due to overload is another typical problem with Stepping motor driven systems. Both phenomena are not detected in open-loop which causes loss of synchronism. In this paper, a sensorless load angle estimator is used to detect step loss and stall. This algorithm is based on the typical Stepping motor drive algorithms and does not depend on mechanical load parameters. The method therefore has a broad industrial relevance.
R.l. Hollis - One of the best experts on this subject based on the ideXlab platform.
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3 dof closed loop control for planar linear Motors
International Conference on Robotics and Automation, 1998Co-Authors: A.e. Quaid, R.l. HollisAbstract:Planar linear Motors (Sawyer Motors) have been used in industry as open-loop Stepping Motors, but their robustness and versatility has been limited. Using a sensor integrated into such a motor, a closed-loop 3-DOF controller has been implemented. The software-based control system consists of a commutator for computing amplifier currents from actuator forces, a force resolution function for solving the redundant actuation and saturation problems, and an observer for producing a velocity estimate, together with a PID controller. Experiments are performed using a 2-axis laser interferometer to show that the controller has sub-micron resolution, 2 /spl mu/m peak-to-peak repeatability, and settling times after trajectories of about 20 ms. Limitations of the PID controller are discussed and ideas for improvements are presented.
Walter Kaiser - One of the best experts on this subject based on the ideXlab platform.
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Stepping-Motor-Driven Constant-Shear-Rate Rotating Viscometer
IEEE Transactions on Instrumentation and Measurement, 2008Co-Authors: Samuel E. De Lucena, Walter KaiserAbstract:Despite the frequent use of Stepping Motors in robotics, automation, and a variety of precision instruments, they can hardly be found in rotational viscometers. This paper proposes the use of a Stepping motor to drive a conventional constant-shear-rate laboratory rotational viscometer to avoid the use of velocity sensor and gearbox and, thus, simplify the instrument design. To investigate this driving technique, a commercial rotating viscometer has been adapted to be driven by a bipolar Stepping motor, which is controlled via a personal computer. Special circuitry has been added to microstep the Stepping motor at selectable step sizes and to condition the torque signal. Tests have been carried out using the prototype to produce flow curves for two standard Newtonian fluids (920 and 12560 mPa middot s, both at 25degC). The flow curves have been obtained by employing several distinct microstep sizes within the shear rate range of 50-500 s-1 . The results indicate the feasibility of the proposed driving technique.
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Stepping motor driven constant-shear-rate rotating viscometer
Proceedings of the 21st IEEE Instrumentation and Measurement Technology Conference (IEEE Cat. No.04CH37510), 2004Co-Authors: Samuel E. De Lucena, Walter KaiserAbstract:Despite the frequent use of Stepping Motors in robotics, automation and in a variety of precision instruments, they can hardly be found in rotational viscometers. This paper proposes the use of a Stepping motor to drive a conventional constant-shear-rate laboratory rotational viscometer, in order to avoid the use of a velocity sensor and gearbox and, thus, simplify the instrument design. To investigate this driving technique, a commercial rotating viscometer has been adapted to be driven by a Stepping motor, which is controlled via a PC. Special circuitry has been added in order to microstep the Stepping motor at a selectable step size, and to condition the torque signal. Tests have been carried out using the prototype to produce three flow curves for a standard Newtonian fluid (920 mPa.s at 25/spl deg/C) but employing a different microstep size for each of them, within the shear rule range from 50 s/sup -1/ to 500 s/sup -1/. The results indicate the feasibility of the proposed driving technique.
