Comparison of properties of electromagnetic clutches with ferromagnetic powder and magnetorheological fluid for low frequency control signals

Author(s):  
Pawel Kielan ◽  
Zbigniew Pilch
Author(s):  
Huy Nguyen ◽  
Omid Bagherieh ◽  
Roberto Horowitz

Track settling control for a hard disk drive with three actuators has been considered. The objective is to settle the read/write head on a specific track by following the minimum jerk trajectory. Robust output feedback model predictive control methodology has been utilized for the control design which can satisfy actuator constraints in the presence of noises and disturbances in the system. The controller is designed based on a low order model of the system and has been applied to a higher order plant in order to consider the model mismatch at high frequencies. Since the settling control generally requires a relatively low frequency control input, simulation result shows that the head can be settled on the desired track with 10 percent of track pitch accuracy while satisfying actuator constraints.


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5307
Author(s):  
Yeying Tao ◽  
Wei Jiang ◽  
Bin Han ◽  
Xiaoqing Li ◽  
Ying Luo ◽  
...  

A piecewise frequency control (PFC) strategy is proposed in this paper for coordinating vibration isolation and positioning of supporting systems under complex disturbance conditions, such as direct and external disturbances. This control strategy is applied in an active-passive parallel supporting system, where relative positioning feedback for positioning and absolute velocity feedback for active vibration isolation. The analysis of vibration and deformation transmissibility shows that vibration control increases low-frequency position error while positioning control amplifies high-frequency vibration amplitude. To overcome this contradiction across the whole control bandwidth, a pair of Fractional-Order Filters (FOFs) is adopted in the PFC system, which increases the flexibility in the PFC design by introducing fraction orders. The system stability analysis indicates that the FOFs can provide a better stability margin than the Integral-Order Filters (IOFs), so the control gains are increased to get a better performance on the AVI and positioning. The PFC based on FOFs can suppress the peak amplitude at the natural frequency which cannot be avoided when using the IOFs. The constrained nonlinear multivariable function is formed by the required performance and the stability of the system, then the controller parameters are optimized effectively. Lastly, the effectiveness of the proposed method is verified by experiments.


Author(s):  
Md. Saiam ◽  
Shah Md. Salimullah ◽  
Md. Shoab Akther ◽  
Md. Zahidul Islam ◽  
Tanjir Hossain Bhuiyan

2020 ◽  
Author(s):  
Mostafa Malekpour ◽  
Arash Kiyoumarsi ◽  
Mehdi Gholipour

This paper proposes an efficient adaptive strategy to control virtual inertia of virtual synchronous generators. This adaptive virtual inertia can provide low frequency oscillation damping and simultaneously improve primary frequency control in power systems. <br>


2021 ◽  
Vol 8 (5) ◽  
pp. 769-774
Author(s):  
Neerudi Bhoopal ◽  
Dokku Sivanaga Malleswara Rao ◽  
Bharath Kumar Narukullapati ◽  
Idamakanti Kasireddy ◽  
Devineni Gireesh Kumar

This paper proposed a new topology of a symmetric single-phase multilevel inverter with the smaller number of semiconductor switches and optimized low-frequency control methods to optimize the Total Harmonic Distortion. A nine-level single phase output is obtained by eight number of active semiconductor switches, four diodes and four capacitors from two asymmetrical dc sources. The selected harmonic order in the output voltage is eliminated by the PWM (SHE-PWM) based on selective harmonic elimination. To optimize the switching angles, an ant colony optimization is introduced. The proposed SHE-PWM and ant optimization are implemented and tested for THD on the SIMULINK platform. The proposed approach offers less THD and is best suited to high-power applications with medium voltage.


2017 ◽  
Author(s):  
F. Barone ◽  
G. Giordano ◽  
R. De Rosa ◽  
F. Acernese ◽  
R. Romano

Plasmonics ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 905-905
Author(s):  
Haruhiko Shirai ◽  
Hiromichi Mitamura ◽  
Nobuaki Arai ◽  
Kazuyuki Moriya

1991 ◽  
Vol 65 (6) ◽  
pp. 1313-1320 ◽  
Author(s):  
H. R. Koerber ◽  
L. M. Mendell

1. Monosynaptic excitatory postsynaptic potentials (EPSPs) were evoked in medial gastrocnemius motoneurons by maximal group Ia stimulation of the heteronymous lateral gastrocnemius-soleus nerve in anesthetized cats. Three different patterns of high-frequency stimulation were delivered to the nerve, and the EPSPs were averaged in register (1, 2, . . ., n) for each. 2. One pattern ("Burst") consisted of 32 shocks delivered every 2 s at an interstimulus interval of 6 ms (167 Hz). The second pattern ("Stepping") was a frequency-modulated burst of 52 shocks derived from a recording of a spindle during stepping and was delivered every 2 s. The third pattern ("Paw Shake") was from an extensor spindle afferent recorded during rapid paw shake and was delivered in groups of six bursts with an interburst interval of 75 ms and a 3-s pause between groups of six bursts. The EPSPs in each burst were averaged in register (1, 2, . . ., n) so that the relative amplitude of each EPSP in the burst could be ascertained. The EPSP produced by low-frequency stimulation of the nerve (18 Hz) was also recorded for each motoneuron. 3. The initial EPSP in most bursts was larger than the EPSP measured as a result of low-frequency stimulation. This potentiation, defined as the ratio of the amplitude of the initial EPSP of the response to that of the low-frequency control, was found to vary systematically as a function of amplitude of the control EPSP as well as the stimulus paradigm used.(ABSTRACT TRUNCATED AT 250 WORDS)


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