Longitudinal Flight Dynamics of Baseline-II BWB UAV

2012 ◽  
Vol 433-440 ◽  
pp. 6636-6640 ◽  
Author(s):  
Rizal E.M. Nasir ◽  
Wahyu Kuntjoro ◽  
Wisnoe Wirachman ◽  
Zurriati Ali

The objective of this paper is to investigate longitudinal flight dynamics of the said aircraft at loitering flight condition near sea level. Three mathematical dynamic models are used to compute transient response of Baseline-II E-2 BWB along with a proposed model known as Model-N. Model-N is derived to incorporate as many important derivatives, including gravitational and pitch angle factor, as possible. While all these four dynamic models are different in a sense where one model is more simple or complex than the others, the basic architecture of all these models are the same. This paper shows the short-period mode needs serious attention. A control algorithm is needed to overcome its handicap which is below Level 3 damping ratio according to MIL-F-8785C. Improvement to phugoid can be considered secondary, but one must ensure that bringing short period mode to Level 1 flying quality does not make phugiod mode response worse than it is now.

1983 ◽  
Vol 105 (3) ◽  
pp. 534-540 ◽  
Author(s):  
Ting W. Lee ◽  
A. C. Wang

This paper deals with a basic problem regarding intermittent-motion mechanisms, namely, how to formulate a predicative model for the study of the dynamics of these mechanisms. A mathematical model is developed in this investigation. The model, which includes clearance, damping, material compliance, and mechanism elasticity, is basic to the determination of the dynamical response such as force amplification and motion characteristics of mechanisms with intermittent motion. A new approach in the modeling of system damping is presented. Instead of using damping ratio, which is difficult to estimate accurately, a new damping function is introduced, which characterizes the speed and load dependent nature of damping. Two types of damping functions are proposed and both of their corresponding damping forces satisfy the expected hysteresis boundary conditions, i.e., zero damping force at zero and maximum relative displacement of contact. A comparative study of the present model with conventional dynamic models is performed. It demonstrates the characteristics and the usefulness of the proposed model for the study of the dynamics of intermittent-motion mechanisms.


2020 ◽  
Author(s):  
C Pulvermacher ◽  
P van de Vondel ◽  
L Gerzen ◽  
U Gembruch ◽  
W Merz
Keyword(s):  
Level 3 ◽  

Author(s):  
Lania Muharsih ◽  
Ratih Saraswati

This study aims to determine the training evaluation at PT. Kujang Fertilizer. PT. Pupuk Kujang is a company engaged in the field of petrochemicals. Evaluation sheet of PT. Fertilizer Kujang is made based on Kirkpatrick's theory which consists of four levels of evaluation, namely reaction, learning, behavior, and results. At level 1, namely reaction, in the evaluation sheet is in accordance with the theory of Kirkpatrick, at level 2 that is learning should be held pretest and posttest but only made scale. At level 3, behavior, according to theory, but on assessment factor number 3, quantity and work productivity should not need to be included because they are included in level 4. At level 4, that is the result, here is still lacking to get a picture of the results of the training that has been carried out because only based on answers from superiors without evidence of any documents.   Keywords: Training Evaluation, Kirkpatrick Theory.    Penelitian ini bertujuan mengetahui evaluasi training di PT. Pupuk Kujang. PT. Pupuk Kujang merupakan perusahaan yang bergerak di bidang petrokimia. Lembar evaluasi PT. Pupuk Kujang dibuat berdasarkan teori Kirkpatrick yang terdiri dari empat level evaluasi, yaitu reaksi, learning, behavior, dan hasil. Pada level 1 yaitu reaksi, di lembar evaluasi tersebut sudah sesuai dengan teori dari Kirkpatrick, pada level 2 yaitu learning seharusnya diadakan pretest dan posttest namun hanya dibuatkan skala. Pada level 3 yaitu behavior, sudah sesuai teori namun pada faktor penilaian nomor 3 kuantitas dan produktivitas kerja semestinya tidak perlu dimasukkan karena sudah termasuk ke dalam level 4. Pada level 4 yaitu hasil, disini masih sangat kurang untuk mendapatkan gambaran hasil dari pelatihan yang sudah dilaksanakan karena hanya berdasarkan dari jawaban atasan tanpa bukti dokumen apapun.   Kata kunci: Evaluasi Pelatihan, Teori Kirkpatrick.


2021 ◽  
Vol 11 (6) ◽  
pp. 2558
Author(s):  
Mario Troise ◽  
Matteo Gaidano ◽  
Pierpaolo Palmieri ◽  
Stefano Mauro

The rising interest in soft robotics, combined to the increasing applications in the space industry, leads to the development of novel lightweight and deployable robotic systems, that could be easily contained in a relatively small package to be deployed when required. The main challenges for soft robotic systems are the low force exertion and the control complexity. In this manuscript, a soft manipulator concept, having inflatable links, is introduced to face these issues. A prototype of the inflatable link is manufactured and statically characterized using a pseudo-rigid body model on varying inflation pressure. Moreover, the full robot model and algorithms for the load and pose estimation are presented. Finally, a control strategy, using inverse kinematics and an elastostatic approach, is developed. Experimental results provide input data for the control algorithm, and its validity domain is discussed on the basis of a simulation model. This preliminary analysis puts the basis of future advancements in building the robot prototype and developing dynamic models and robust control.


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
H Subbiah Ponniah ◽  
M Ahmed ◽  
T Edwards ◽  
J Cobb ◽  
E Dean ◽  
...  

Abstract Introduction There are now over 2.5 million NHS patients awaiting elective surgery, with the most in orthopaedics. We present an algorithm and results for safely and equitably restarting surgery at COVID-light sites. Method An MDT applied the COVID-19 Algorithm for Resuming Elective Surgery (CARES) on 1169 patients awaiting elective orthopaedic surgery. It assessed safety, procedural efficacy, and biopsychosocial factors, to prioritise patients. They were assigned to five categories and underwent surgery at one of three COVID-light sites (1. access to HDU/ITU/Paediatrics/specialist equipment, 2. an NHS elective surgical unit and 3. a private elective surgical unit). Results 21 ‘Urgent’ patients received expedited care; 118 were Level 1/2; 222 were Level 3; 808 were Level 4. In 6 weeks, 355 surgeries were performed, with Urgent and Level 1/2 cases performed soonest (mean 18 days, p < 0.001). 33 high-risk/complex/paediatric patients had surgery at Site 1 and the rest at Sites 2 and 3. No patients contracted COVID-19 within 2 weeks of surgery. Conclusions We validated a widely generalisable model to facilitate resumption of elective surgery in COVID-light sites. It enabled surgery for patients in most suffering, undergoing the most efficacious procedures and/or at highest risk of deterioration, without compromising patient-safety.


Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 920
Author(s):  
Liesle Caballero ◽  
Álvaro Perafan ◽  
Martha Rinaldy ◽  
Winston Percybrooks

This paper deals with the problem of determining a useful energy budget for a mobile robot in a given environment without having to carry out experimental measures for every possible exploration task. The proposed solution uses machine learning models trained on a subset of possible exploration tasks but able to make predictions on untested scenarios. Additionally, the proposed model does not use any kinematic or dynamic models of the robot, which are not always available. The method is based on a neural network with hyperparameter optimization to improve performance. Tabu List optimization strategy is used to determine the hyperparameter values (number of layers and number of neurons per layer) that minimize the percentage relative absolute error (%RAE) while maximize the Pearson correlation coefficient (R) between predicted data and actual data measured under a number of experimental conditions. Once the optimized artificial neural network is trained, it can be used to predict the performance of an exploration algorithm on arbitrary variations of a grid map scenario. Based on such prediction, it is possible to know the energy needed for the robot to complete the exploration task. A total of 128 tests were carried out using a robot executing two exploration algorithms in a grid map with the objective of locating a target whose location is not known a priori by the robot. The experimental energy consumption was measured and compared with the prediction of our model. A success rate of 96.093% was obtained, measured as the percentage of tests where the energy budget suggested by the model was enough to actually carry out the task when compared to the actual energy consumed in the test, suggesting that the proposed model could be useful for energy budgeting in actual mobile robot applications.


Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 869
Author(s):  
Xiuguo Zou ◽  
Jiahong Wu ◽  
Zhibin Cao ◽  
Yan Qian ◽  
Shixiu Zhang ◽  
...  

In order to adequately characterize the visual characteristics of atmospheric visibility and overcome the disadvantages of the traditional atmospheric visibility measurement method with significant dependence on preset reference objects, high cost, and complicated steps, this paper proposed an ensemble learning method for atmospheric visibility grading based on deep neural network and stochastic weight averaging. An experiment was conducted using the scene of an expressway, and three visibility levels were set, i.e., Level 1, Level 2, and Level 3. Firstly, the EfficientNet was transferred to extract the abstract features of the images. Then, training and grading were performed on the feature sets through the SoftMax regression model. Subsequently, the feature sets were ensembled using the method of stochastic weight averaging to obtain the atmospheric visibility grading model. The obtained datasets were input into the grading model and tested. The grading model classified the results into three categories, with the grading accuracy being 95.00%, 89.45%, and 90.91%, respectively, and the average accuracy of 91.79%. The results obtained by the proposed method were compared with those obtained by the existing methods, and the proposed method showed better performance than those of other methods. This method can be used to classify the atmospheric visibility of traffic and reduce the incidence of traffic accidents caused by atmospheric visibility.


Author(s):  
Hashem Ashrafiuon

Abstract This paper presents the effect of foundation flexibility on the optimum design of vibration absorbers. Flexibility of the base is incorporated into the absorber system equations of motion through an equivalent damping ratio and stiffness value in the direction of motion at the connection point. The optimum values of the uncoupled natural frequency and damping ratio of the absorber are determined over a range of excitation frequencies and the primary system damping ratio. The design parameters are computed and compared for the rigid, static, and dynamic models of the base as well as different levels of base flexibility.


2002 ◽  
Vol 6 (2) ◽  
pp. 185-219 ◽  
Author(s):  
Adam Ockelford

Like all fields of human artistic endeavour, music is constrained by our cognitive processing requirements and limitations (Swain, 1986; Lerdahl, 1988; Huron, 2001). This articleconsiders particular forms of constraint pertaining to the relationships that the structure-seeking mind (subconsciously) fabricates between perceived musical events. It is proposed that 2±1 may be a universal limitation pertaining to the level of relationships so ideated. That is, in terms of Lewin'S (1987) theoretical framework in which “intervals” can be intuited between the “elements” of musical “spaces”, it is posited that the cognition of musical structure occurs either through intervals (level 1), through intervals between these (level 2), or — in some circumstances — through intervals between these(level 3). This proposition is explored through the psychomusicological model developed by Ockelford (1991, 1993, 1999), which too analyses musical structure in terms of the relationships that may be cognised between its discrete perceptual components. In particular, the model identifies a type of cognitive link through which events (at any level) arefelt to imply others the same or similar — through so-called “zygonic” relationships. This theory suggests a further general principle: that the highest level of relationship inoperation at any given point must be zygonic if the music is to be structurally coherent. Evidence for this, and for the limit on the level of relationships of 2±1, is offeredthrough a series of musical examples, which illustrate a variety of musical organisation in action. Finally, empirical work is suggested to explore further the theoretical ideas that arepresented here.


2003 ◽  
Vol 31 (6) ◽  
pp. 1472-1473 ◽  
Author(s):  
A. Finney ◽  
M. Hucka

The SBML (systems biology markup language) is a standard exchange format for computational models of biochemical networks. We continue developing SBML collaboratively with the modelling community to meet their evolving needs. The recently introduced SBML Level 2 includes several enhancements to the original Level 1, and features under development for SBML Level 3 include model composition, multistate chemical species and diagrams.


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