Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming.Although there exist diverse bi-stable structures capable of snap-throug...Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming.Although there exist diverse bi-stable structures capable of snap-through instability,it is still difficult for a structure with high slenderness to undergo the axial snap-through instability with a large stroke.Here,an elastic structure with high slenderness is simply constructed by a finite number of identical,conventional bi-stable units with relatively low slenderness in series connection.For realizing the axial snap-through instability with a large stroke,common scissors mechanisms are further introduced as rigid constraints to guarantee the synchronous snap-through instability of these bi-stable units.The global feature of the large-stroke snap-through instability realized here is robust and even insusceptible to the local out-of-synchronization of individual units.The present design provides a simple and feasible way to achieve the large-stroke snap-through instability of slender structures,which is expected to be particularly useful for state switching and energy transforming in narrow spaces.展开更多
This paper addresses a critical challenge in the design of MEMS actuators:the rejection of out-of-plane motion,specifically along the Z-axis,which can severely impact the precision and performance of these micro-actua...This paper addresses a critical challenge in the design of MEMS actuators:the rejection of out-of-plane motion,specifically along the Z-axis,which can severely impact the precision and performance of these micro-actuation systems.In many MEMS applications,unwanted out-of-plane displacement can lead to reduced accuracy in tasks such as optical steering,micro-manipulation,and scanning applications.In response to these limitations,this paper proposes a novel design technique that effectively rejects Z-axis motion by transforming the motion of the micro stage along the Z-axis into equivalent displacements between pairs of points on cantilevers.These point pairs are founded exhibiting variable common-mode and differential-mode motion characteristics,depending on whether the stage is undergoing in-plane(X/Y)or out-of-plane(Z)displacements.By connecting these point pairs with rods,differential motion between the points in the pairs is suppressed,reducing unwanted out-of-plane motion significantly.We provide a detailed analysis of this design methodology and present a practical application in the form of an electromagnetic large displacement MEMS actuator.This actuator undergoes a complete design-simulationmanufacturing-testing cycle,where the effectiveness of the Z-axis motion rejection structure is systematically evaluated,and compared against traditional designs.Experimental results reveal a significant improvement in performance,with static and dynamic travel ranges reaching±60μm and±400μm,respectively.Moreover,the Z-axis stiffness was enhanced by 68.5%,which is more than five times the improvement observed in the X/Y axes’stiffness.These results highlight the potential of the proposed method to provide a robust solution for out-of-plane motion suppression in MEMS actuators,offering improved performance without compromising other critical parameters such as displacement and actuation speed.展开更多
This hybrid transducer type linear ultrasonic motor is a new troe of the lineax ultrasonic motor proposed by the authors. This paper describes its basic structure and operation principle, provides its mechedsm of the ...This hybrid transducer type linear ultrasonic motor is a new troe of the lineax ultrasonic motor proposed by the authors. This paper describes its basic structure and operation principle, provides its mechedsm of the large thrust and large seif lock force when power is cut off. The measured characteristics of the prototype motor are shown, its mtalmum thrust is 11 N and mtalmum output power is 1.4 W, the backward and forward motion performances are roughly coincident展开更多
A quasi-isotropic, quasi-homogeneous turbulence generated by an oscillating-grid, spatially decays according to power law of u ∝ Z-nM , where u is the root mean square （rms） horizontal velocity, Z is the vertical d...A quasi-isotropic, quasi-homogeneous turbulence generated by an oscillating-grid, spatially decays according to power law of u ∝ Z-nM , where u is the root mean square （rms） horizontal velocity, Z is the vertical distance from the grid and nu = 1. However, the findings of Nokes and Yi indicate that as the stroke of oscillation increases, the power law n u= 1 and does not follow the established decay law equation of Hopfinger. This paper investigates the characteristics of the turbulence that are generated using larger strokes S/M = 1.6 and 2 and compares with that obtained using a S/M = 0.8, which is the stroke used when the equation was developed. Measurements of the grid-generated turbulence in a water tank were taken using particle image velocimetry （PIV）. The results showed that the homogeneity occurred at distance beyond 2.5 mesh spacings away from the grid midplane, independent of the stroke and the frequency of oscillation. Within this region, the turbulent kinetic energy distribution was quasi-homogeneous, and the secondary mean flow is negligible. The statistical characteristics of the measured turbulence confirmed that although nu decreases as stroke increases, the grid-turbulence generated at S/M = 1.6 and 2 obeys the universal decay law.展开更多
Acute ischemic stroke is one of the common discases in Chinese,among which acute ischemic stroke with large vessel occlusion(AIS-LVO)has thc most serious complications and has the risk of death.Studies have shown that...Acute ischemic stroke is one of the common discases in Chinese,among which acute ischemic stroke with large vessel occlusion(AIS-LVO)has thc most serious complications and has the risk of death.Studies have shown that reperfusion is a first-line treatment for the effective rescue of ischemic brain tissue,usually mainly by mechanical|hrombectomy(MT),supplemented by intravenous thrombolysis.However,there are still complications after large blood vessel occlusion and MT.such as blecding and infection at the puncture point,vasospasm,vascular dissection,subarachnoid hemorrhage,hcmonhagic transfomation,reembolization,and massive cerebral infarction,ctc.The high risk factors and corresponding measures of complications after MT by revicwing the rescarch analysis.展开更多
Patients who received endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) and large-scaled core infarct volume in the time window were analyzed. Literature data were reviewed. Re...Patients who received endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) and large-scaled core infarct volume in the time window were analyzed. Literature data were reviewed. Results showed that although EVT is the first choice to AIS-LVO, patients often have poor prognosis. Alberta stroke program early CT score (ASPECTS) based on computerized tomography angiography source image (CTA-SI) can reflect the real cerebral perfusion more truly, and it can assess the size of core infarct more quickly and accurately, thus enabling to judge prognosis.展开更多
Genome-wide association studies have found that rs17612742 increases the risk of large artery atherosclerotic stroke.The rs17612742 was located in the intron region of Endothelin receptor type A(NRA),which was cellula...Genome-wide association studies have found that rs17612742 increases the risk of large artery atherosclerotic stroke.The rs17612742 was located in the intron region of Endothelin receptor type A(NRA),which was cellular and gender-heterogeneous.Functional genomics studies of rs17612742 were carried out through some public databases,and it was found that rs17612742 was located in the chromatin open region and promoted the expression of NRA.Compared with the control group,EDNRA expression increased in middle cerebral artery occlusion exposed rodents.However,age heterogeneity of EDNRA expression under physiological and pathological conditions was not observed.In addition,we also discussed how to conduct further empirical studies to provide evidence that rs17612742 confers the risk of large artery atherosclerotic stroke by increasing the expression of NRA.展开更多
Coiled polymer artificial muscles with both large tensile stroke and giant force generation are needed for practical applications in robotics,soft exosuits,and prosthesis.However,most polymer yarn artificial muscles c...Coiled polymer artificial muscles with both large tensile stroke and giant force generation are needed for practical applications in robotics,soft exosuits,and prosthesis.However,most polymer yarn artificial muscles cannot generate a large force or stress.Here,we report an inexpensive Twisted and Coiled Polymer artificial muscle(TCP)that performs both large isobaric and isometric contractions.This TCP can generate a tensile stroke of 20.1%and a specific work capacity of up to 1.3 kJ kg^(−1) during temperature changes from 20 to 180℃.Moreover,the nylon yarn artificial muscle produced a reversible output stress of 28.4 MPa,which is 100 times larger than human skeletal muscle.A robot arm and a simple gripper were made to demonstrate the isobaric actuation and isometric actuation of our TCP muscle,repectivley.Thus,the polymer artificial muscles with dual-mode actuation show potential applications in the field of robotics,grippers,and exoskeletons and so on.展开更多
Background The impact of lowering systolic blood pressure(SBP)following endovascular treatment(EVT)in acute large vessel occlusion stroke(LVOS)patients remains unclear.We aimed to explore the effect of the magnitude o...Background The impact of lowering systolic blood pressure(SBP)following endovascular treatment(EVT)in acute large vessel occlusion stroke(LVOS)patients remains unclear.We aimed to explore the effect of the magnitude of SBP reduction(SBPr)after EVT on outcomes in LVOS patients.Methods We consecutively registered patients at three comprehensive stroke centres who had experienced EVT as a result of acute anterior circulation LVOS.SBPr was calculated as follows:(baseline SBP−mean SBP/baseline SBP)×100%.The 90-day modified Rankin Scale score ranging from 0 to 2 was defined as a favourable functional outcome.Based on CT scans obtained within 24 hours after procedure,symptomatic intracranial haemorrhage(sICH)was assessed according to the criteria of the European Cooperative Acute Stroke Study III.Results We enrolled 1080 patients,of which 908(84.1%)had successful recanalisation.In the overall cohort,SBPr was correlated with lower odds of sICH(SBPr±10%as a reference,20%-30%:OR 0.460;95%CI:0.245 to 0.864;p=0.016;>30%:OR 0.304;95%CI 0.123 to 0.749;p=0.010).In patients who achieved successful reperfusion,SBPr>30%was correlated with higher odds of a poor outcome(SBPr±10%as a reference,OR 2.150;95%CI 1.268 to 3.645;p=0.004)and SBPr has a similar tendency towards reducing the incidence of sICH.In the subgroup analyses,baseline Alberta Stroke Programme Early CT(ASPECT)score(p_(interact)=0.024)modified the effect of SBPr on the 90-day outcome.Conclusion Among patients with EVT,a significant drop in SBP may be related to a poor functional outcome and a reduced incidence of sICH.Baseline ASPECT score may be an important interacting factor in the association of SBPr with the 90-day outcome.This study provides new insights for individualised BP management in patients with EVT.展开更多
Objectives Endovascular therapy(EVT)now penetrates the once obscure realm of large infarct core volume acute ischaemic stroke(LICV-AIS).This research aimed to investigate the potential correlation between different an...Objectives Endovascular therapy(EVT)now penetrates the once obscure realm of large infarct core volume acute ischaemic stroke(LICV-AIS).This research aimed to investigate the potential correlation between different anaesthetic approaches and post-EVT outcomes in LICV-AIS patients.Methods Between October 2020 and May 2022,the China ANGEL-Alberta Stroke Programme Early CT Score(ASPECT)trial studied patients with LICV-AIS,randomly assigning them to the best medical management(BMM)or BMM with EVT.This post hoc subgroup analysis categorised subjects receiving BMM with EVT into general anaesthesia(GA)and non-GA groups based on anaesthesia type.We applied multivariable logistic regression to evaluate the relationship between anaesthesia during EVT and patient functional outcomes,as measured by the modified Rankin scale(mRS),in addition to the occurrence of complications.Further adjustment for selection bias was achieved through propensity score matching(PSM).Results In total,230 patients with LICV-AIS were enrolled(GA 84 vs Non-GA 146).No significant difference was observed between the two groups in terms of the proportion of patients who achieved an mRS score of 0-2 at 90 days(27.4%for the GA group vs 31.5%for the non-GA group,p=0.51).However,the GA group had significantly longer median surgical times(142 min vs 122 min,p=0.03).Furthermore,GA was associated with an increased risk of postoperative pneumonia(adjusted OR 2.03,95%CI 1.04 to 3.98).The results of PSM analysis agreed with the results of the multivariate regression analysis.No significant difference in intracranial haemorrhage incidence or mortality rate was observed between the groups.Conclusion This post hoc analysis of subgroups of the ANGEL-ASPECT trial suggested that there may be no significant association between the choice of anaesthesia and neurological outcomes in LICV-AIS patients.However,compared with non-GA,GA prolongs the duration of EVT and is associated with a greater postoperative pneumonia risk.展开更多
The linear ultrasonic motor(LUSM)has many merits such as high precision,quick response,self-locking when power off and so on.However,it also has some drawbacks such as strong non-linear and time-varying characteristic...The linear ultrasonic motor(LUSM)has many merits such as high precision,quick response,self-locking when power off and so on.However,it also has some drawbacks such as strong non-linear and time-varying characteristics,which are harmful to high precision positioning.Fig.1 shows a positioning stage driven by LUSMs.In this paper,the macro-micro control mode is adopted to realize the requirements of the large-workspace and high precision positioning.The switching macro-micro control depends on switching threshold,and it can be described as follows(E denotes the position error,D denotes switching threshold):When E>D,the PID based macro control method is adopted to realize large stroke and quick response;When E≤D,the normal distribution theory combined with the technology of fuzzy logic approach is employed to realize high precision positioning.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11972027,12472093,and 11772272)the New Interdisciplinary Cultivation Fund of Southwest Jiaotong University(Grant No.2682022JX001)+1 种基金the Frontier Science and Technology Cultivation Project of Southwest Jiaotong University(Grant No.2682022KJ048)the Laboratory of Flexible Electronics Technology at Tsinghua University.
文摘Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming.Although there exist diverse bi-stable structures capable of snap-through instability,it is still difficult for a structure with high slenderness to undergo the axial snap-through instability with a large stroke.Here,an elastic structure with high slenderness is simply constructed by a finite number of identical,conventional bi-stable units with relatively low slenderness in series connection.For realizing the axial snap-through instability with a large stroke,common scissors mechanisms are further introduced as rigid constraints to guarantee the synchronous snap-through instability of these bi-stable units.The global feature of the large-stroke snap-through instability realized here is robust and even insusceptible to the local out-of-synchronization of individual units.The present design provides a simple and feasible way to achieve the large-stroke snap-through instability of slender structures,which is expected to be particularly useful for state switching and energy transforming in narrow spaces.
基金the National Natural Science Foundation of China(Grant No.U21A6003&Grant No.U24A6006).
文摘This paper addresses a critical challenge in the design of MEMS actuators:the rejection of out-of-plane motion,specifically along the Z-axis,which can severely impact the precision and performance of these micro-actuation systems.In many MEMS applications,unwanted out-of-plane displacement can lead to reduced accuracy in tasks such as optical steering,micro-manipulation,and scanning applications.In response to these limitations,this paper proposes a novel design technique that effectively rejects Z-axis motion by transforming the motion of the micro stage along the Z-axis into equivalent displacements between pairs of points on cantilevers.These point pairs are founded exhibiting variable common-mode and differential-mode motion characteristics,depending on whether the stage is undergoing in-plane(X/Y)or out-of-plane(Z)displacements.By connecting these point pairs with rods,differential motion between the points in the pairs is suppressed,reducing unwanted out-of-plane motion significantly.We provide a detailed analysis of this design methodology and present a practical application in the form of an electromagnetic large displacement MEMS actuator.This actuator undergoes a complete design-simulationmanufacturing-testing cycle,where the effectiveness of the Z-axis motion rejection structure is systematically evaluated,and compared against traditional designs.Experimental results reveal a significant improvement in performance,with static and dynamic travel ranges reaching±60μm and±400μm,respectively.Moreover,the Z-axis stiffness was enhanced by 68.5%,which is more than five times the improvement observed in the X/Y axes’stiffness.These results highlight the potential of the proposed method to provide a robust solution for out-of-plane motion suppression in MEMS actuators,offering improved performance without compromising other critical parameters such as displacement and actuation speed.
文摘This hybrid transducer type linear ultrasonic motor is a new troe of the lineax ultrasonic motor proposed by the authors. This paper describes its basic structure and operation principle, provides its mechedsm of the large thrust and large seif lock force when power is cut off. The measured characteristics of the prototype motor are shown, its mtalmum thrust is 11 N and mtalmum output power is 1.4 W, the backward and forward motion performances are roughly coincident
基金Universiti Kebangsaan Malaysia for the financial support during the author’s postgraduate studies
文摘A quasi-isotropic, quasi-homogeneous turbulence generated by an oscillating-grid, spatially decays according to power law of u ∝ Z-nM , where u is the root mean square （rms） horizontal velocity, Z is the vertical distance from the grid and nu = 1. However, the findings of Nokes and Yi indicate that as the stroke of oscillation increases, the power law n u= 1 and does not follow the established decay law equation of Hopfinger. This paper investigates the characteristics of the turbulence that are generated using larger strokes S/M = 1.6 and 2 and compares with that obtained using a S/M = 0.8, which is the stroke used when the equation was developed. Measurements of the grid-generated turbulence in a water tank were taken using particle image velocimetry （PIV）. The results showed that the homogeneity occurred at distance beyond 2.5 mesh spacings away from the grid midplane, independent of the stroke and the frequency of oscillation. Within this region, the turbulent kinetic energy distribution was quasi-homogeneous, and the secondary mean flow is negligible. The statistical characteristics of the measured turbulence confirmed that although nu decreases as stroke increases, the grid-turbulence generated at S/M = 1.6 and 2 obeys the universal decay law.
基金High Level Talent Program of Hainan Natural Science Foundation(No.821RC680)。
文摘Acute ischemic stroke is one of the common discases in Chinese,among which acute ischemic stroke with large vessel occlusion(AIS-LVO)has thc most serious complications and has the risk of death.Studies have shown that reperfusion is a first-line treatment for the effective rescue of ischemic brain tissue,usually mainly by mechanical|hrombectomy(MT),supplemented by intravenous thrombolysis.However,there are still complications after large blood vessel occlusion and MT.such as blecding and infection at the puncture point,vasospasm,vascular dissection,subarachnoid hemorrhage,hcmonhagic transfomation,reembolization,and massive cerebral infarction,ctc.The high risk factors and corresponding measures of complications after MT by revicwing the rescarch analysis.
文摘Patients who received endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) and large-scaled core infarct volume in the time window were analyzed. Literature data were reviewed. Results showed that although EVT is the first choice to AIS-LVO, patients often have poor prognosis. Alberta stroke program early CT score (ASPECTS) based on computerized tomography angiography source image (CTA-SI) can reflect the real cerebral perfusion more truly, and it can assess the size of core infarct more quickly and accurately, thus enabling to judge prognosis.
文摘Genome-wide association studies have found that rs17612742 increases the risk of large artery atherosclerotic stroke.The rs17612742 was located in the intron region of Endothelin receptor type A(NRA),which was cellular and gender-heterogeneous.Functional genomics studies of rs17612742 were carried out through some public databases,and it was found that rs17612742 was located in the chromatin open region and promoted the expression of NRA.Compared with the control group,EDNRA expression increased in middle cerebral artery occlusion exposed rodents.However,age heterogeneity of EDNRA expression under physiological and pathological conditions was not observed.In addition,we also discussed how to conduct further empirical studies to provide evidence that rs17612742 confers the risk of large artery atherosclerotic stroke by increasing the expression of NRA.
基金Financial support from the program of the National Natural Science Foundation of China (Grant no.52105057,51905222)Natural Science Foundation of Jiangsu Province (Grant no.BK20200916)+3 种基金China Postdoctoral Science Foundation (no.2021M691307,no.2022T150274)Jiangsu Postdoctoral Research Foundation (no.2021K543C)Key Research Project of Zhejiang LabSenior Talent Foundation of Jiangsu University (Grant no.5501110013)are acknowledged.
文摘Coiled polymer artificial muscles with both large tensile stroke and giant force generation are needed for practical applications in robotics,soft exosuits,and prosthesis.However,most polymer yarn artificial muscles cannot generate a large force or stress.Here,we report an inexpensive Twisted and Coiled Polymer artificial muscle(TCP)that performs both large isobaric and isometric contractions.This TCP can generate a tensile stroke of 20.1%and a specific work capacity of up to 1.3 kJ kg^(−1) during temperature changes from 20 to 180℃.Moreover,the nylon yarn artificial muscle produced a reversible output stress of 28.4 MPa,which is 100 times larger than human skeletal muscle.A robot arm and a simple gripper were made to demonstrate the isobaric actuation and isometric actuation of our TCP muscle,repectivley.Thus,the polymer artificial muscles with dual-mode actuation show potential applications in the field of robotics,grippers,and exoskeletons and so on.
基金supported by the Natural Science Research Projects in Anhui Universities(2022AH051244)the Scientific Research Fund Project for Talent Introduction of Yijishan Hospital,Wannan Medical College in China(No.YR202111,YR202210)+2 种基金the Health Research Program of Anhui in China(No.AHWJ2022b090)Key Research Project of Wannan Medical College(No.WK2023ZZD21)Wuhu Science and Technology Project(No.2023JC28).
文摘Background The impact of lowering systolic blood pressure(SBP)following endovascular treatment(EVT)in acute large vessel occlusion stroke(LVOS)patients remains unclear.We aimed to explore the effect of the magnitude of SBP reduction(SBPr)after EVT on outcomes in LVOS patients.Methods We consecutively registered patients at three comprehensive stroke centres who had experienced EVT as a result of acute anterior circulation LVOS.SBPr was calculated as follows:(baseline SBP−mean SBP/baseline SBP)×100%.The 90-day modified Rankin Scale score ranging from 0 to 2 was defined as a favourable functional outcome.Based on CT scans obtained within 24 hours after procedure,symptomatic intracranial haemorrhage(sICH)was assessed according to the criteria of the European Cooperative Acute Stroke Study III.Results We enrolled 1080 patients,of which 908(84.1%)had successful recanalisation.In the overall cohort,SBPr was correlated with lower odds of sICH(SBPr±10%as a reference,20%-30%:OR 0.460;95%CI:0.245 to 0.864;p=0.016;>30%:OR 0.304;95%CI 0.123 to 0.749;p=0.010).In patients who achieved successful reperfusion,SBPr>30%was correlated with higher odds of a poor outcome(SBPr±10%as a reference,OR 2.150;95%CI 1.268 to 3.645;p=0.004)and SBPr has a similar tendency towards reducing the incidence of sICH.In the subgroup analyses,baseline Alberta Stroke Programme Early CT(ASPECT)score(p_(interact)=0.024)modified the effect of SBPr on the 90-day outcome.Conclusion Among patients with EVT,a significant drop in SBP may be related to a poor functional outcome and a reduced incidence of sICH.Baseline ASPECT score may be an important interacting factor in the association of SBPr with the 90-day outcome.This study provides new insights for individualised BP management in patients with EVT.
基金funded by Covidien Healthcare International Trading(Shanghai),Johnson&Johnson MedTech,Genesis MedTech(Shanghai)and Shanghai HeartCare Medical Technologysupported by the Clinical Medicine Development of Special Funding Support(ZYLX201708+2 种基金DFL20180502)the Beijing Municipal Science&Technology Commission(Z19110700660000)the Capital’s Funds for Health Improvement and Research(CFH 2024-2-2046).
文摘Objectives Endovascular therapy(EVT)now penetrates the once obscure realm of large infarct core volume acute ischaemic stroke(LICV-AIS).This research aimed to investigate the potential correlation between different anaesthetic approaches and post-EVT outcomes in LICV-AIS patients.Methods Between October 2020 and May 2022,the China ANGEL-Alberta Stroke Programme Early CT Score(ASPECT)trial studied patients with LICV-AIS,randomly assigning them to the best medical management(BMM)or BMM with EVT.This post hoc subgroup analysis categorised subjects receiving BMM with EVT into general anaesthesia(GA)and non-GA groups based on anaesthesia type.We applied multivariable logistic regression to evaluate the relationship between anaesthesia during EVT and patient functional outcomes,as measured by the modified Rankin scale(mRS),in addition to the occurrence of complications.Further adjustment for selection bias was achieved through propensity score matching(PSM).Results In total,230 patients with LICV-AIS were enrolled(GA 84 vs Non-GA 146).No significant difference was observed between the two groups in terms of the proportion of patients who achieved an mRS score of 0-2 at 90 days(27.4%for the GA group vs 31.5%for the non-GA group,p=0.51).However,the GA group had significantly longer median surgical times(142 min vs 122 min,p=0.03).Furthermore,GA was associated with an increased risk of postoperative pneumonia(adjusted OR 2.03,95%CI 1.04 to 3.98).The results of PSM analysis agreed with the results of the multivariate regression analysis.No significant difference in intracranial haemorrhage incidence or mortality rate was observed between the groups.Conclusion This post hoc analysis of subgroups of the ANGEL-ASPECT trial suggested that there may be no significant association between the choice of anaesthesia and neurological outcomes in LICV-AIS patients.However,compared with non-GA,GA prolongs the duration of EVT and is associated with a greater postoperative pneumonia risk.
文摘The linear ultrasonic motor(LUSM)has many merits such as high precision,quick response,self-locking when power off and so on.However,it also has some drawbacks such as strong non-linear and time-varying characteristics,which are harmful to high precision positioning.Fig.1 shows a positioning stage driven by LUSMs.In this paper,the macro-micro control mode is adopted to realize the requirements of the large-workspace and high precision positioning.The switching macro-micro control depends on switching threshold,and it can be described as follows(E denotes the position error,D denotes switching threshold):When E>D,the PID based macro control method is adopted to realize large stroke and quick response;When E≤D,the normal distribution theory combined with the technology of fuzzy logic approach is employed to realize high precision positioning.
