The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
E Urata - One of the best experts on this subject based on the ideXlab platform.
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influence of unequal air gap thickness in servo valve Torque Motors
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2007Co-Authors: E UrataAbstract:AbstractThe current paper considers servo valve Torque Motors having four air-gaps. An ideal for these types of Torque Motors is to have four equal air-gaps at free state. However, real servo valve Torque Motors have unequal air-gaps due to production errors. Because the influence of the inequality of air-gaps is not clear, servo valve manufacturers have made great efforts to establish the equality of the air-gaps. The current paper gives a prospect on how an imbalance of air-gaps changes the flux densities in the air-gaps and the resultant Torque characteristic. An important result of the paper is that some of the air-gap imbalance induces a Torque change of magnitude of second- or higher-powers of the imbalance. The imbalance of the air-gaps due to different pole heights results in an offset proportional to the magnitude of the imbalance. These results can be used for setting a tolerance limit for air-gap thickness.
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on the Torque generated in a servo valve Torque motor using permanent magnets
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2007Co-Authors: E UrataAbstract:AbstractThis paper describes a theory and experiments for the conversion of electric current to mechanical Torque by a Torque motor in servo valves. The feature of the Torque motor treated in this paper is the use of a permanent magnet. These kinds of Torque Motors are most commonly used in modern servo valves. For this type of Torque motor, the theory developed by Merritt is most notable among fluid power engineers and scientists. However, his theory does not agree very well with experiments because he ignored the magnetic reluctance and leakage flux of permanent magnets. This paper corrects these points and offers some formulae that agree well with experiments.
Yuan Huang - One of the best experts on this subject based on the ideXlab platform.
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event triggered active disturbance rejection control of dc Torque Motors
IEEE-ASME Transactions on Mechatronics, 2017Co-Authors: Lixun Zhao, Junzheng Wang, Yuan HuangAbstract:Physical servo systems are affected by disturbances, uncertainties, and resource restrictions. In this paper, an event-triggered active disturbance rejection control approach is proposed to achieve position tracking of dc Torque Motors. An event-based sampler together with an extended state observer is introduced, which allows the joint observation of the system state, and the total disturbance induced by model uncertainty and intermittent sampling. Based on the observation results, closed-loop control is achieved with guaranteed stable tracking performance. To quantify the effect of event-based sampling, a quantitative relationship between the asymptotic upper bound of tracking error and the parameters in the event-based sampler is developed. The control strategy is applied to a dc Torque motor system, and comparative experimental results indicate that for different reference signals, the proposed event-based control strategy can achieve satisfactory tracking performance with reduced sampling cost.
Lixun Zhao - One of the best experts on this subject based on the ideXlab platform.
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event triggered active disturbance rejection control of dc Torque Motors
IEEE-ASME Transactions on Mechatronics, 2017Co-Authors: Lixun Zhao, Junzheng Wang, Yuan HuangAbstract:Physical servo systems are affected by disturbances, uncertainties, and resource restrictions. In this paper, an event-triggered active disturbance rejection control approach is proposed to achieve position tracking of dc Torque Motors. An event-based sampler together with an extended state observer is introduced, which allows the joint observation of the system state, and the total disturbance induced by model uncertainty and intermittent sampling. Based on the observation results, closed-loop control is achieved with guaranteed stable tracking performance. To quantify the effect of event-based sampling, a quantitative relationship between the asymptotic upper bound of tracking error and the parameters in the event-based sampler is developed. The control strategy is applied to a dc Torque motor system, and comparative experimental results indicate that for different reference signals, the proposed event-based control strategy can achieve satisfactory tracking performance with reduced sampling cost.
David R Hendrixso - One of the best experts on this subject based on the ideXlab platform.
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diverse high Torque bacterial flagellar Motors assemble wider stator rings using a conserved protein scaffold
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Morga Eeby, Deborah A Ribardo, Caitli A Enna, Edward G Ruby, Gra J Jense, David R HendrixsoAbstract:Although it is known that diverse bacterial flagellar Motors produce different Torques, the mechanism underlying Torque variation is unknown. To understand this difference better, we combined genetic analyses with electron cryo-tomography subtomogram averaging to determine in situ structures of flagellar Motors that produce different Torques, from Campylobacter and Vibrio species. For the first time, to our knowledge, our results unambiguously locate the Torque-generating stator complexes and show that diverse high-Torque Motors use variants of an ancestrally related family of structures to scaffold incorporation of additional stator complexes at wider radii from the axial driveshaft than in the model enteric motor. We identify the protein components of these additional scaffold structures and elucidate their sequential assembly, demonstrating that they are required for stator-complex incorporation. These proteins are widespread, suggesting that different bacteria have tailored Torques to specific environments by scaffolding alternative stator placement and number. Our results quantitatively account for different motor Torques, complete the assignment of the locations of the major flagellar components, and provide crucial constraints for understanding mechanisms of Torque generation and the evolution of multiprotein complexes.
Junzheng Wang - One of the best experts on this subject based on the ideXlab platform.
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event triggered active disturbance rejection control of dc Torque Motors
IEEE-ASME Transactions on Mechatronics, 2017Co-Authors: Lixun Zhao, Junzheng Wang, Yuan HuangAbstract:Physical servo systems are affected by disturbances, uncertainties, and resource restrictions. In this paper, an event-triggered active disturbance rejection control approach is proposed to achieve position tracking of dc Torque Motors. An event-based sampler together with an extended state observer is introduced, which allows the joint observation of the system state, and the total disturbance induced by model uncertainty and intermittent sampling. Based on the observation results, closed-loop control is achieved with guaranteed stable tracking performance. To quantify the effect of event-based sampling, a quantitative relationship between the asymptotic upper bound of tracking error and the parameters in the event-based sampler is developed. The control strategy is applied to a dc Torque motor system, and comparative experimental results indicate that for different reference signals, the proposed event-based control strategy can achieve satisfactory tracking performance with reduced sampling cost.