scholarly journals Adaptive Kinematic Modelling for Multiobjective Control of a Redundant Surgical Robotic Tool

Robotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 68
Author(s):  
Francesco Cursi ◽  
George P. Mylonas ◽  
Petar Kormushev
Keyword(s):  
Kinematic Model ◽  
Adaptive Strategy ◽  
Machine Learning Techniques ◽  
Effective Control ◽  
Surgical Robots ◽  
Tracking Errors ◽  
Kinematic Modelling ◽  
Kinematic Models ◽  
Robotic Tool ◽  
And Control

Accurate kinematic models are essential for effective control of surgical robots. For tendon driven robots, which are common for minimally invasive surgery, the high nonlinearities in the transmission make modelling complex. Machine learning techniques are a preferred approach to tackle this problem. However, surgical environments are rarely structured, due to organs being very soft and deformable, and unpredictable, for instance, because of fluids in the system, wear and break of the tendons that lead to changes of the system’s behaviour. Therefore, the model needs to quickly adapt. In this work, we propose a method to learn the kinematic model of a redundant surgical robot and control it to perform surgical tasks both autonomously and in teleoperation. The approach employs Feedforward Artificial Neural Networks (ANN) for building the kinematic model of the robot offline, and an online adaptive strategy in order to allow the system to conform to the changing environment. To prove the capabilities of the method, a comparison with a simple feedback controller for autonomous tracking is carried out. Simulation results show that the proposed method is capable of achieving very small tracking errors, even when unpredicted changes in the system occur, such as broken joints. The method proved effective also in guaranteeing accurate tracking in teleoperation.

Verification of a Wheeled Mobile Robot Dynamic Model and Control Ramifications

1999 ◽  
Vol 121 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Daehie Hong ◽  
Steven A. Velinsky ◽  
Xin Feng
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Kinematic Model ◽  
High Load ◽  
Wheeled Mobile Robots ◽  
Model Based Control ◽  
Practical Applications ◽  
High Speeds ◽  
Kinematic Models ◽  
And Control

For low speed, low acceleration, and lightly loaded applications, kinematic models of Wheeled Mobile Robots (WMRs) provide reasonably accurate results. However, as WMRs are designed to perform more demanding, practical applications with high speeds and/or high loads, kinematic models are no longer valid representations. This paper includes experimental results for a heavy, differentially steered WMR for both loaded and unloaded conditions. These results are used to verify a recently developed dynamic model which includes a complex tire representation to accurately account for the tire/ground interaction. The dynamic model is then exercised to clearly show the inadequacy of kinematic models for high load and/or high speed conditions. Furthermore, through simulation, the failure of kinematic model based control for such applications is also shown.

Geometric and Kinematic Modelling of a New Parallel Kinematic Machine Tool: The Tripteor X7 Designed by PCI

2010 ◽  
Vol 112 ◽  
pp. 159-169 ◽  
Author(s):  
Sylvain Pateloup ◽  
Helene Chanal ◽  
Emmanuel Duc
Keyword(s):  
Machine Tools ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Parallel Kinematic Machine ◽  
Joint Coordinates ◽  
Kinematic Behaviour ◽  
Kinematic Modelling ◽  
Kinematic Models ◽  
Automotive Part ◽  
Parallel Kinematic

Today, Parallel Kinematic Machine tools (PKMs) appear in automotive and aeronautic industry. These machines propose high kinematic performances allowing a higher productivity than Serial Kinematic Machine tools (SKMs). However, this kinematic behaviour is anisotropic and a particular study is then necessary to locate the part in a workspace where the kinematic performances are well exploited. The study presented in this article deals with the determination of geometric and kinematic models of a new PKM : the Tripteor X7 designed by PCI. The inverse kinematic model expresses the joint coordinates with regard to the cartesian coordinates. The kinematic model which takes into account velocity, acceleration and jerk limits axis, allows computing the displacement time between two tool positions. Finally, this model can be used to determine the workspace where Non Effective cutting Times (TNE) are minimum. The method is applied for an automotive part machining

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 Constraining families of dynamic models using geological, geodetic and strong ground motion data: the Mw 6.5, October 30th, 2016, Norcia earthquake, Italy

2021 ◽  
Author(s):  
Elisa Tinti ◽  
Emanuele Casarotti ◽  
Thomas Ulrich ◽  
Duo Li ◽  
Taufiqurrahman Taufiqurrahman ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Central Italy ◽  
Kinematic Model ◽  
Seismic Wave Propagation ◽  
Dynamic Rupture ◽  
Friction Coefficients ◽  
Multiple Faults ◽  
Central Italy Earthquake ◽  
Trade Offs ◽  
Kinematic Models

The 2016 Central Italy earthquake sequence is characterized by remarkable rupture complexity, including highly heterogeneous slip across multiple faults in an extensional tectonic regime. The dense coverage and high quality of geodetic and seismic data allow to image intriguing details of the rupture kinematics of the largest earthquake of the sequence, the Mw 6.5 October 30th, 2016 Norcia earthquake, such as an energetically weak nucleation phase. Several kinematic models suggest multiple fault planes rupturing simultaneously, however, the mechanical viability of such models is not guaranteed.Using 3D dynamic rupture and seismic wave propagation simulations accounting for two fault planes, we constrain 'families' of spontaneous dynamic models informed by a high-resolution kinematic rupture model of the earthquake. These families differ in their parameterization of initial heterogeneous shear stress and strength in the framework of linear slip weakening friction.First, we dynamically validate the kinematically inferred two-fault geometry and rake inferences with models based on only depth-dependent stress and constant friction coefficients. Then, more complex models with spatially heterogeneous dynamic parameters allow us to retrieve slip distributions similar to the target kinematic model and yield good agreement with seismic and geodetic observations. We discuss the consistency of the assumed constant or heterogeneous static and dynamic friction coefficients with mechanical properties of rocks at 3-10 km depth characterizing the Italian Central Apennines and their local geological and lithological implications. We suggest that suites of well-fitting dynamic rupture models belonging to the same family generally exist and can be derived by exploiting the trade-offs between dynamic parameters.Our approach will be applicable to validate the viability of kinematic models and classify spontaneous dynamic rupture scenarios that match seismic and geodetic observations at the same time as geological constraints.

scholarly journals Kinematic Modelling of FES Induced Sit-to-stand Movement in Paraplegia

2017 ◽  
Vol 7 (6) ◽  
pp. 3060
Author(s):  
Mohammed Ahmed ◽  
M. S. Huq ◽  
B. S. K. K. Ibrahim
Keyword(s):  
Dynamic Model ◽  
Initial Phase ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Future Research ◽  
Upper Limbs ◽  
Body System ◽  
Segmental Dynamics ◽  
Sit To Stand ◽  
Kinematic Modelling

FES induced movements from indication is promising due to encouraging results being obtained by scholars. The kinematic model usually constitute the initial phase towards achieving the segmental dynamics of any rigid body system. It can be used to ascertain that the model is capable of achieving the desired goal. The dynamic model builds on the kinematic model and is usually mathematically cumbersome depending on the number of degrees-of-freedom. This paper presents a kinematic model applicable for human sit-to-stand movement scenario that will be used to obtain the dynamic model the FES induced movement in a later study. The study shows that the 6 DOF conceptualized sit-to-stand movement can be achieved conveniently using 4 DOF. The 4 DOF has an additional joint compared to similar earlier works which makes more it accurate and flexible. It is more accurate in the sense that it accommodates additional joint i.e. the neck joint whose dynamics could be captured. And more flexible in the sense that if future research uncover more contributions by the segments it can be easily incorporated including that of other segments e.g. the trunk, neck and upper limbs.

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.

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