Tremor suppression strategy of the tremor suppression robot

Based on the development of the performance of magnetorheological damper,the tremor suppression strategy that uses angle displacement sensor and force sensor to sense the information of the tremor and uses the fuzzy neural network as the control algorithm is presented. The information of the maximum tremor torque can be achieved exactly by means fusing the data of displacement sensor and the data of force sensor. Due to the slow change of the maximum tremor torque,the fuzzy neural network with single input variable and single output variable is adopted as the control algorithm,and the mathematic model of fuzzy neural network is worked out. The elbow tremor suppression model is established to provide tremor information for fuzzy neural network training and tremor suppression strategy simulation,then the off-line fuzzy neural network training is finished with the selected training data set,and the tremor suppression strategy is simulated. Simulation results show that the tremor suppression strategy has presented is effectually for the tremor suppression.

Progress on Transition Metal Ions Dissolution Suppression Strategies in Prussian Blue Analogs for Aqueous Sodium-/Potassium-Ion Batteries

Aqueous sodium-ion batteries(ASIBs)and aqueous potassium-ion batteries(APIBs)present significant potential for large-scale energy storage due to their cost-effectiveness,safety,and environmental compatibility.Nonetheless,the intricate energy storage mechanisms in aqueous electrolytes place stringent require-ments on the host materials.Prussian blue analogs(PBAs),with their open three-dimensional framework and facile synthesis,stand out as leading candidates for aqueous energy storage.However,PBAs possess a swift capacity fade and limited cycle longevity,for their structural integrity is compromised by the pronounced dis-solution of transition metal(TM)ions in the aqueous milieu.This manuscript provides an exhaustive review of the recent advancements concerning PBAs in ASIBs and APIBs.The dissolution mechanisms of TM ions in PBAs,informed by their structural attributes and redox processes,are thoroughly examined.Moreover,this study delves into innovative design tactics to alleviate the dissolution issue of TM ions.In conclusion,the paper consolidates various strategies for suppressing the dissolution of TM ions in PBAs and posits avenues for prospective exploration of high-safety aqueous sodium-/potassium-ion batteries.

Overview on Resonance Characteristics and Resonance Suppression Strategy of Multi-Parallel Photovoltaic Inverters

Photovoltaic(PV)inverters have been widely used in large-scale PV power generation systems to reduce the system mismatch and increase the output power.With the increasing installed capacity of PV power stations,the number of string PV inverters increases,which brings about risk of inverter resonance and influences the quality and stability of multi-parallel inverters grid-connected system.Thus,the problems of multi-parallel inverters resonance have become a hot research topic.This paper is focused on the case of grid-connected string PV inverter systems,and the grid-connected PV inverter resonance where resonance suppression strategy will be analyzed and discussed.Firstly,the structure of string PV inverter and multi-parallel inverters system are presented.Secondly,discussions are made about the model of multi-parallel inverters system and its resonance characteristics based on the multi-input-multi-output(MIMO)system,Norton equivalent circuit and carrier synchronization.Thirdly,two strategies of^inverter level"and"system level"are provided to summarize the multi-parallel inverters resonance suppression strategy.Finally,the development tendency of resonance suppression strategy and conclusions are prospected.

Interactive Power Oscillation and Its Suppression Strategy for VSG-DSG Paralleled System in Islanded Microgrid

A virtual synchronous generator(VSG)can provide inertial support through renewables and energy storage.It generally operates in parallel with a diesel generator(DSG)in an islanded microgrid.However,unforeseen interactive power oscillations occur in the paralleled system when loads fluctuate.These may also burn out the VSG owing to its low overcurrent capacity.The mechanism and suppression strategy of the power oscillation of a VSG-DSG paralleled system are investigated.It reveals that the interactive power oscillation is caused essentially by the physical difference and parameter mismatch between the VSG and DSG.Then,the elimination condition of oscillation generation is derived.Subsequently,a comprehensive suppression control strategy based on virtual inductance and dynamic mutual damping technology is proposed.Finally,the experimental results verify the effectiveness of the proposed method.

Suppression Strategy of Micro-waviness error in Ultra-precision Parallel Grinding

Ultra-precision parallel grinding is widely used in the machining of complex optic components with high tolerance and excellent surface finish.However,the micro-waviness raised from the relative motion error of the grinding tool is frequently involved in the grinding process despite the fine dressing and dynamic balance work carried out,which posed a remarkable impact on the surface quality and form accuracy.Therefore,it is essential to investigate the evolution mechanism of the micro-waviness error and determine a relevant strategy to suppress this kind of error.In this paper,a model of the distribution of grinding points corresponding to the relative motion error of the grinding wheel is developed by considering the phase effect.A close relationship is found between the micro-waviness geometry and the distribution of grinding points.This indicates that the phase shift is a significant parameter to determine the waviness pattern,and the uniform distribution of grinding points is beneficial to suppress the micro-waviness in parallel grinding.Finally,an error-suppression strategy is proposed by adjusting the wheel speed to maintain an appropriate phase shift to suppress the micro-waviness error.This work provides a new method to control the micro-waviness and reduce the effect of the waviness error on the surface generation.

Harmonic State-Space Based AC-Side Impedance Model of MMC and High Frequency Oscillation Characteristics Analysis

Recently,high-frequency oscillation of themodularmultilevel converter(MMC)based high-voltage direct current(HVDC)projects has attracted great attentions.In order to analyze the small-signal stability,this paper uses the harmonic state-space(HSS)method to establish a detailed frequency domain impedance model of the AC-side of the HVDC transmission system,which considers the internal dynamic characteristics.In addition,the suggested model is also used to assess the system’s high-frequency oscillationmechanism,and the effects of the MMC current inner loop control,feedforward voltage links,and control delay on the high-frequency impedance characteristics and the effect of higher harmonic components.Finally,three oscillation suppression schemes are analyzed for the oscillation problems occurring in actual engineering,and a simplified impedance model considering only the highfrequency impedance characteristics is established to compare the suppression effect with the detailed impedance model to prove its reliability.

Recent research advances of self-discharge in supercapacitors:Mechanisms and suppressing strategies

Supercapacitors are one of the most promising energy storage devices in the fields of vehicle transportation,flexible electronic devices,aerospace,etc.However,the existed self-discharge that is the spontaneous voltage decay after supercapacitors are fully charged,brings about the wide gap between experimental studies and practical utilization of supercapacitors.Although eliminating the selfdischarge completely is not reachable,suppressing the self-discharge rate to the lowest point is possible and feasible.So far,the significant endeavors have been devoted to achieve this goal.Herein,we summary and discuss the possible mechanisms for the self-discharge and the underlying influence factors.Moreover,the strategies to suppress the self-discharge are systemically summed up by three independent but unified aspects:modifying the electrode,modulating the electrolyte and tuning the separator.Finally,the major challenges to suppress the self-discharge of supercapacitors are concluded and the promising strategies are also pointed out and discussed.This review is presented with the view of serving as a guideline to suppress the self-discharge of supercapacitors and to across-the-board facilitate their widespread application.

Global Asymptotic Stability in a Delay Differential Equation Model for Mosquito Population Suppression

A bio-safe dengue control strategy is to use Wolbachia,which can induce incomplete cytoplasmic incompatibility(CI)and reduce the mating competitiveness of infected males.In this work,we formulate a delay differential equation model,including both the larval and adult stages of wild mosquitoes,to assess the impacts of CI intensityξand mating competitivenessθof infected males on the suppression efficiency.Our analysis identifies a CI intensity thresholdξ*below which a successful suppression is impossible.Whenξ≥ξ*,the wild population will be eliminated ultimately if the releasing level exceeds the release amount threshold R*uniformly.The dependence of R*onξandθ,and the impact of temperature on suppression are further exhibited through numerical examples.Our analyses indicate that a slight reduction ofξis more devastating than significantly decrease ofθin the suppression efficiency.To suppress more than 95%wild mosquitoes during the peak season of dengue in Guangzhou,the optimal starting date for releasing is sensitive toξbut almost independent ofθ.One percent reduction ofξfrom 1 requires at least one week earlier in the optimal releasing starting date from 7 weeks ahead of the peak season of dengue.