Formulation and control of robots with link and joint flexibility

Robotica ◽  
1993 ◽  
Vol 11 (3) ◽  
pp. 273-282 ◽  
Author(s):  
Sachin Gogate ◽  
Yueh-Jaw Lin
Keyword(s):  
Effective Control ◽  
Nonlinear Feedback ◽  
Joint Flexibility ◽  
Vibration Model ◽  
Modes Of Vibration ◽  
Manipulator Link ◽  
Joint Elasticity ◽  
Simultaneous Existence ◽  
Link Flexibility ◽  
And Control

SUMMARYPresent study on industrial manipulator control either completely neglects structural flexibility or only considers manipulator link flexibility. Ignoring joint flexibility may cause significant errors in gross motion control if the joint elastic effect is predominant. This paper presents an effective control scheme which can compensate for the motion errors generated by simultaneous existence of both link and joint flexibility. The manipulator dynamics is formulated comprehensively by a superposition of two models, namely, an assumed modes of vibration model for links and a torsional spring model.for joints. Then, a nonlinear feedback rate servo control system is developed that compensates for the gross motion errors introduced by both joint elasticity and link flexibility. Motion simulation results show that the proposed formulation can effectively describe the dynamic behavior of a flexible-link, elastic-joint robot. They also verify that the proposed controller is robust in that it can satisfactorily suppress the manipulator end oscillations and yield an accurate gross motion.

Survey and control of small mammal populations on two hardwood plantations in southern Ontario

1974 ◽  
Vol 50 (5) ◽  
pp. 181-185 ◽  
Author(s):  
Andrew Radvanyi
Keyword(s):  
Small Mammal ◽  
Late Summer ◽  
Control Measures ◽  
Effective Control ◽  
Southern Ontario ◽  
Live Trapping ◽  
Surrounding Areas ◽  
And Control ◽  
Rodent Populations ◽  
Ingredient Cost

Live trapping and tagging methods were employed to assess small mammal populations within two hardwood plantations in southern Ontario. Excessive girdling damage in past years to young planted trees necessitated an evaluation of rodent populations and development of effective control measures. The application of an anticoagulant rodenticide to oat groats bait broadcast over the study area at an ingredient cost of approximately three dollars per acre virtually wiped out the small mammals. Reinvasion from surrounding areas was, however, fairly rapid, particularly during late summer. Further research on longer term control measures using poisoned bait feeder stations is recommended.

scholarly journals Confirmation and Control of HPPD-Inhibiting Herbicide–Resistant Waterhemp (Amaranthus tuberculatus) in Nebraska

2017 ◽  
Vol 31 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Maxwel C. Oliveira ◽  
Amit J. Jhala ◽  
Todd Gaines ◽  
Suat Irmak ◽  
Keenan Amundsen ◽  
...  
Keyword(s):  
Dose Response ◽  
Field Conditions ◽  
Effective Control ◽  
Herbicide Resistant ◽  
Greenhouse Experiments ◽  
Amaranthus Tuberculatus ◽  
Sites Of Action ◽  
And Control ◽  
Herbicide Programs

Field and greenhouse experiments were conducted in Nebraska to (1) confirm the 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting resistant-waterhemp biotype (HPPD-RW) by quantifying the resistance levels in dose-response studies, and (2) to evaluate efficacy of PRE-only, POST-only, and PRE followed by POST herbicide programs for control of HPPD-RW in corn. Greenhouse dose-response studies confirmed that the suspected waterhemp biotype in Nebraska has evolved resistance to HPPD-inhibiting herbicides with a 2- to 18-fold resistance depending upon the type of HPPD-inhibiting herbicide being sprayed. Under field conditions, at 56 d after treatment, ≥90% control of the HPPD-RW was achieved with PRE-applied mesotrione/atrazine/S-metolachlor+acetochlor, pyroxasulfone (180 and 270 g ai ha−1), pyroxasulfone/fluthiacet-methyl/atrazine, and pyroxasulfone+saflufenacil+atrazine. Among POST-only herbicide programs, glyphosate, a premix of mesotrione/atrazine tank-mixed with diflufenzopyr/dicamba, or metribuzin, or glufosinate provided ≥92% HPPD-RW control. Herbicide combinations of different effective sites of action in mixtures provided ≥86% HPPD-RW control in PRE followed by POST herbicide programs. It is concluded that the suspected waterhemp biotype is resistant to HPPD-inhibiting herbicides and alternative herbicide programs are available for effective control in corn. The occurrence of HPPD-RW in Nebraska is significant because it limits the effectiveness of HPPD-inhibiting herbicides.

scholarly journals Detection and Control Bacteria Cause Grain Rot Burkholderia glumae on Rice

2019 ◽  
Vol 23 (2) ◽  
pp. 163
Author(s):  
Syahri Syahri ◽  
Renny Utami Somantri ◽  
Priatna Sasmita
Keyword(s):  
Rainfall Intensity ◽  
Effective Control ◽  
Burkholderia Glumae ◽  
Physiological Factors ◽  
Tropical Area ◽  
Resistant Varieties ◽  
Central Production ◽  
Production Areas ◽  
And Control ◽  
Group 1

Burkholderia glumae, before mid-2018, is categorized as plant quarantine pest A2 Group 1 that its existence has been detected in Indonesia. B. glumae  has been known to spread in the central production of rice in Java, Sumatra, Borneo dan Sulawesi. This review aimed to explain the strategies for B. glumae detection through its characteristics and to prevent the divergence  of this bacterium in Indonesia. The previous studies reported that the bacteria could reduce yield up to 75% and caused the decrease  of weight-grain or the increase  of empty grain. The disease intensity is affected by environmental and physiological factors such as warm temperature at nighttime and high rainfall intensity. The optimum temperature for the development of the disease is 30–35°C. Moreover, the pathogen could survive at a temperature of 41°C. The tropical area of 32-36°C are suitable for B. glumae. Recently, the effective control of the disease in the field has not been found yet. Meanwhile, early detection of the disease is not yet determined,  even though  it is necessary  to prevent its spread in rice cultivation in Indonesia. Detection of the disease by Agricultural Quarantine Agency as a frontline is needed to check the entry of the disease carried by the import activities of the seed. Detection in the suspected field by protection institutes through frequent surveillance in central production areas of rice should be considered  as an important task.. The effective techniques to prevent B. glumae are the use of resistant varieties, the practice of seed treatments (using antibacterial, bactericide, heat treatment or plant extract), and  the application of oxolinic acid to the crops.

scholarly journals Assessing the Dynamics and Control of Droplet- and Aerosol-Transmitted Influenza Using an Indoor Positioning System

2017 ◽  
Author(s):  
Timo Smieszek ◽  
Gianrocco Lazzari ◽  
Marcel Salathé
Keyword(s):  
Wireless Sensors ◽  
Public Spaces ◽  
Mitigation Strategies ◽  
Effective Control ◽  
Positioning System ◽  
Close Physical Proximity ◽  
Close Proximity ◽  
Dynamics And Control ◽  
And Control ◽  
Indoor Positioning System

ABSTRACTThere is increasing evidence that aerosol transmission is a major contributor to the spread of influenza. Despite this, virtually all studies assessing the dynamics and control of influenza assume that it is transmitted solely through direct contact and large droplets, requiring close physical proximity. Here, we use wireless sensors to measure simultaneously both the location and close proximity contacts in the population of a US high school. This dataset, highly resolved in space and time, allows us to model both droplet and aerosol transmission either in isolation or in combination. In particular, it allows us to computationally assess the effectiveness of overlooked mitigation strategies such as improved ventilation that are available in the case of aerosol transmission. While the effects of the type of transmission on disease outbreak dynamics appear to be weak, we find that good ventilation could be as effective in mitigating outbreaks as vaccinating the majority of the population. In simulations using empirical transmission levels observed in households, we find that bringing ventilation to recommended levels has the same mitigating effect as a vaccination coverage of 50% to 60%. Our results therefore suggest that improvements of ventilation in public spaces could be an important and easy-to-implement strategy supplementing vaccination efforts for effective control of influenza spread.

scholarly journals Effective control measures limited measles outbreak after extensive nosocomial exposures in January-February 2008 in Gothenburg, Sweden

2008 ◽  
Vol 13 (30) ◽  
Author(s):  
P Follin ◽  
L Dotevall ◽  
M Jertborn ◽  
Y Khalid ◽  
J Å Liljeqvist ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Control Measures ◽  
Effective Control ◽  
Imported Case ◽  
Measles Outbreak ◽  
Measles Outbreaks ◽  
Rubella Vaccination ◽  
And Control

In January-February 2008, one imported case of measles initiated a series of exposures with around 380 nosocomial secondary contacts. Susceptible individuals were traced early and control measures were initiated that managed to limit the consequences considerably. Only four secondary cases were identified by the end of March. This minor outbreak illustrates the importance and efficiency of early control measures as well as the fact that the risk of measles outbreaks still exists in a country that has high measles, mumps, rubella vaccination coverage among children.

Analysis and Control of Unknown In-Vehicle Network System

2012 ◽  
Vol 184-185 ◽  
pp. 1521-1525
Author(s):  
Yu En Wu ◽  
Yu Hui Hu ◽  
Ya Ying Jin ◽  
Jun Qiang Xi
Keyword(s):  
Dynamic Analysis ◽  
Static Analysis ◽  
Effective Control ◽  
Hybrid Powertrain ◽  
Verification Method ◽  
Gateway System ◽  
Powertrain System ◽  
Analytical Protocol ◽  
Key Aspects ◽  
And Control

A CAN-Bus protocol analysis and verification method with three key aspects which are static analysis, dynamic analysis and verification &control is put forward. Static analysis ascertains the communication information of each node by bus residual method; Synchronous contrast method is put in use to obtain practical and effective control protocol in the dynamic analysis; Verification &control is to verify the correctness of the analytical protocol and to achieve the control of the critical subsystems by bus gateway system. This scheme has been used to analyze a foreign parallel hybrid powertrain system, and it proves the correctness of the designed static analysis and dynamic analysis, the applicability of verification &control.

scholarly journals Dynamics of bed bug infestations and control under disclosure policies

2019 ◽  
Vol 116 (13) ◽  
pp. 6473-6481 ◽  
Author(s):  
Sherrie Xie ◽  
Alison L. Hill ◽  
Chris R. Rehmann ◽  
Michael Z. Levy
Keyword(s):  
Cost Benefit ◽  
Control Policy ◽  
Spillover Effects ◽  
The United States ◽  
Effective Control ◽  
Bed Bugs ◽  
Bed Bug ◽  
Highly Nonlinear ◽  
Public Health Practitioners ◽  
And Control

Bed bugs have reemerged in the United States and worldwide over recent decades, presenting a major challenge to both public health practitioners and housing authorities. A number of municipalities have proposed or initiated policies to stem the bed bug epidemic, but little guidance is available to evaluate them. One contentious policy is disclosure, whereby landlords are obligated to notify potential tenants of current or prior bed bug infestations. Aimed to protect tenants from leasing an infested rental unit, disclosure also creates a kind of quarantine, partially and temporarily removing infested units from the market. Here, we develop a mathematical model for the spread of bed bugs in a generalized rental market, calibrate it to parameters of bed bug dispersion and housing turnover, and use it to evaluate the costs and benefits of disclosure policies to landlords. We find disclosure to be an effective control policy to curb infestation prevalence. Over the short term (within 5 years), disclosure policies result in modest increases in cost to landlords, while over the long term, reductions of infestation prevalence lead, on average, to savings. These results are insensitive to different assumptions regarding the prevalence of infestation, rate of introduction of bed bugs from other municipalities, and the strength of the quarantine effect created by disclosure. Beyond its application to bed bugs, our model offers a framework to evaluate policies to curtail the spread of household pests and is appropriate for systems in which spillover effects result in highly nonlinear cost–benefit relationships.

Yellow Nutsedge (Cyperus esculentus) Competition and Control in Corn (Zea mays)

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 32-37 ◽  
Author(s):  
E. W. Stoller ◽  
L. M. Wax ◽  
F. W. Slife
Keyword(s):  
Zea Mays ◽  
Control Measures ◽  
Effective Control ◽  
Yield Reduction ◽  
Cyperus Esculentus ◽  
Yellow Nutsedge ◽  
Effective Combination ◽  
Percentage Yield ◽  
Hand Weeding ◽  
And Control

Competition of yellow nutsedge (Cyperus esculentusL.) with corn (Zea maysL.) was evaluated in the field at various yellow nutsedge densities over a 3-yr period. A relationship between yellow nutsedge density (shoots/m2) and percentage yield reduction revealed an 8% yield reduction for every 100 shoots/m2. Two 3-yr studies were conducted to determine the most effective combination of preplant-incorporated, postemergence, or postemergence-directed treatments for yellow nutsedge control in corn. The preplant incorporated treatments were alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], EPTC (S-ethyl dipropylthiocarbamate), or nothing; postemergence treatments were bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2,2-dioxide], two cultivations, or nothing; and the postemergence-directed treatments were ametryn [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine] or nothing. One preplant-incorporated treatment of EPTC or alachlor prevented yield reductions from yellow nutsedge competition. When no control was practiced, yields were reduced 17% in a moderate yellow nutsedge infestation (initially infested with 300 tubers/m2) and 41% in a heavy infestation (initially infested with 1200 tubers/m2). Yields were reduced 7 to 8% in the moderate infestation when no preplant-incorporated treatments were used regardless of whether postemergence or postemergence-directed treatments were also used. After 1 yr, all control measures resulted in less tuber density than no control measures, but all control treatments had essentially similar tuber densities. After the second year, several herbicide treatments were as effective as hand weeding in reducing tuber density. At least 2 yr of effective control treatments were required to reduce tubers to 20% of the original density, and 3 yr of treatment to reduce the density to 15% of the original density. No combination of treatments, including hand weeding, eliminated tubers after 3 yr.

Development of Electronic Control Unit for Air Suspension with Fuzzy Control

2013 ◽  
Vol 457-458 ◽  
pp. 774-777
Author(s):  
Can Chen
Keyword(s):  
Fuzzy Control ◽  
Electronic Control Unit ◽  
Control Unit ◽  
Electronic Control ◽  
Air Suspension ◽  
Vibration Model ◽  
The One ◽  
And Control ◽  
Vehicle Vibration Model ◽  
Stiffness Adjustment

The paper is based on the one-quarter vehicle vibration model of air suspension system with auxiliary chamber and stiffness adjustment theory and control characteristic of air suspension are discussed. On the basis, fuzzy control theory without mathematical precise model was applied to design the air suspension controller, and then an electronic control unit for air suspension is developed.

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