Algebraic Driver Steering Model Parameter Identification

Modeling driver steering behavior plays an ever-important role in nowadays automotive dynamics and control applications. Especially, understanding individuals' steering characteristics enables the advanced driver assistance systems (ADAS) to adapt to particular drivers, which provides enhanced protection while mitigating human-machine conflict. Driver-adaptive ADAS requires identifying the parameters inside a driver steering model in real-time to account for driving characteristics variations caused by weather, lighting, road, or driver physiological conditions. Usually, Recursive Least Squares (RLS) and Kalman Filter (KF) are employed to update the driver steering model parameters online. However, because of their asymptotical nature, the convergence speed of the identified parameters could be slow. In contrast, this paper adopts a purely algebraic perspective to identify parameters of a driver steering model, which can achieve parameter identification within a short period. To demonstrate the effectiveness of the proposed method, we first apply synthetic driver steering data from simulation to show its superior performance over an RLS identifier in identifying constant model parameters, including feedback steering gain, feedforward steering gain, preview time, and first-order neuromuscular lag. Then, we utilize real measurement data from human subject driving simulator experiments to illustrate how the time-varying feedback and feedforward steering gains can be updated online via the algebraic method.

AVALIAÇÃO DE DESEMPENHO DO MICROASPERSOR EM LINHA LATERAL E SIMULAÇÃO MATEMÁTICA DE SEU GRADIENTE DE ENERGIA

AVALIAÇÃO DE DESEMPENHO DO MICROASPERSOR EM LINHA LATERAL E SIMULAÇÃO MATEMÁTICA DE SEU GRADIENTE DE ENERGIA MADSON RAFAEL BARBALHO DA SILVA1; LÍVIA MARIA CAVALCANTE SILVA1; ANA CLÁUDIA DAVINO DOS SANTOS1; FABIANO SIMPLICIO BEZERRA1; CAIO SÉRGIO PEREIRA DE ARAÚJO1 E MANASSÉS MESQUITA DA SILVA1 1 Departamento de Engenharia Agrícola, Universidade Federal Rural de Pernambuco, Dom Manuel de Medeiros, s/n, Dois Irmãos, 52171-900, Recife, Pernambuco, Brasil. E-mail:[email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]. 1 RESUMO Objetivou-se avaliar o desempenho do microaspersor Agropolo modelo MC20 em diferentes condições hidráulicas, gerando informações para um melhor dimensionamento de sistemas de microirrigação e manejo da água em áreas irrigadas. A condução do projeto hidráulico para simulação do gradiente de energia em linhas laterais, considerou-se informações determinadas através da escolha de componentes do projeto. Foram extraídos do catálogo comercial do fabricante os pares de valores referentes a vazão e a pressão e, a partir destes, gerou-se a curva vazão-pressão, onde a simulação foi feita pelo Método Algébrico - Christiansen (MA) e Método Iterativo (SBS) – Back-Step. Para ambos métodos o microaspersor se comportou de maneira semelhante, quando submetido a condições sugeridas pelo fabricante, num espaçamento entre emissores de 5,2 m, usando tubos de polietilenos de diâmetro interno de 13 mm e uma pressão de serviço de 20 mca, admitindo uma variação de 10% da pressão. Foram calculados os coeficientes de uniformidade de pressão (CUp) e de vazão (CUq), ambos com valores superiores à 95%, demonstrando a excelência no desempenho do emissor. Palavras-chave: hidráulica, modelagem matemática, coeficiente de descarga. SILVA, M. R. B.; SILVA, L. M. C.; SANTOS, A. C. D.; BEZERRA, F. S.; ARAUJO, C. S. P.; SILVA, M. M. PERFORMANCE EVALUATION OF THE SIDE LINE MICROSPARENT AND MATHEMATICAL SIMULATION OF ITS ENERGY GRADIENT 2 ABSTRACT The objective was to evaluate the performance of the Agropolo model MC20 microsprinkler under different hydraulic conditions, generating information for a better design of micro-irrigation systems and water management in irrigated areas. The conduction of the hydraulic project to simulate the energy gradient in lateral lines, considered information determined through the choice of project components. The pairs of values ​​referring to flow and pressure were extracted from the manufacturer's commercial catalog and, from these, the flow-pressure curve was generated, where the simulation was performed using the Algebraic Method - Christiansen (MA) and Iterative Method (SBS) – Back-Step. For both methods, the microsprinkler behaved similarly, when subjected to conditions suggested by the manufacturer, in a spacing between emitters of 5.2 m, using polyethylene tubes with an internal diameter of 13 mm and a working pressure of 20 mca, admitting a 10% pressure variation. The uniformity of pressure (CUp) and flow (CUq) coefficients were calculated, both with values ​​above 95%, demonstrating the excellence in the performance of the emitter. Keywords: hydraulic, mathematical modeling, discharge coefficient.

Algebra Based Human Skeleton Sequence Reduction and Action Recognition

Skeleton-based human action recognition is a research hotspot in recent years, but most of the research focuses on the spatio-temporal feature extraction by convolutional neural network. In order to improve the correct recognition rate of these models, this paper proposes three strategies: using algebraic method to reduce redundant video frames, adding auxiliary edges into the joint adjacency graph to improve the skeleton graph structure, and adding some virtual classes to disperse the error recognition rate. Experimental results on NTU-RGB-D60, NTU-RGB-D120 and Kinetics Skeleton 400 databases show that the proposed strategy can effectively improve the accuracy of the original algorithm.

Theoretical and computational improvements to the algebraic method for discovering cooperative rigid-unit modes

A linear-algebraic algorithm for identifying rigid-unit modes in networks of interconnected rigid units has recently been demonstrated. This article presents a series of enhancements to the original algorithm, which greatly improve its conceptual simplicity, numerical robustness, computational efficiency and interpretability. The improvements include the efficient isolation of constraints, the observation of variable-block separability, the use of singular value decomposition and a quantitative measure of solution inexactness.

Development of Task-Space Nonholonomic Motion Planning Algorithm Based on Lie-Algebraic Method

In this paper, a Lie-algebraic nonholonomic motion planning technique, originally designed to work in a configuration space, was extended to plan a motion within a task-space resulting from an output function considered. In both planning spaces, a generalized Campbell–Baker–Hausdorff–Dynkin formula was utilized to transform a motion planning into an inverse kinematic task known for serial manipulators. A complete, general-purpose Lie-algebraic algorithm is provided for a local motion planning of nonholonomic systems with or without output functions. Similarities and differences in motion planning within configuration and task spaces were highlighted. It appears that motion planning in a task-space can simplify a planning task and also gives an opportunity to optimize a motion of nonholonomic systems. Unfortunately, in this planning there is no way to avoid working in a configuration space. The auxiliary objective of the paper is to verify, through simulations, an impact of initial parameters on the efficiency of the planning algorithm, and to provide some hints on how to set the parameters correctly.

Algebraic Method for Exact Synthesis of 1-DOF Linkages With Arbitrarily Prescribed Constant Velocity Ratios

This paper addresses the synthesis of 1-DOF linkages that can exactly transmit angular motion between coplanar axes (i.e. parallel axes or intersectant axes) with arbitrarily prescribed constant velocity ratios. According to motion polynomials over dual quaternions and pure rolling models between two circles, an algebraic approach is presented to precisely synthesize new 1-DOF linkages with arbitrarily prescribed constant velocity ratios. The approach includes four steps: (a) formulate a characteristic curve occurred by the pure rolling, (b) compute the motion polynomial of the minimal degree that can generate the curve, (c) deal with the factorization of the motion polynomial to construct an open chain, (d) convert the open chain to a 1-DOF linkage. Using this approach, several 1-DOF planar, spherical, and spatial linkages for angular motion transmission between parallel axes or intersectant ones are constructed by designating various velocity ratios. Taking the planar and spherical linkages with a constant 1:2 velocity ratio as examples, kinematics analysis is implemented to prove their motion characteristics. The result shows that the generated linkages indeed can transmit angular motion between two coplanar axes with constant velocity ratios. Meanwhile, 3D-printed prototypes of these linkages also demonstrate such a conclusion. This work provides a framework for synthesizing linkages that have great application potential to transmit motion in robotic systems that require low inertia to achieve reciprocating motion with high speed and accuracy.

Renormalization in Combinatorially Non-Local Field Theories: the BPHZ Momentum Scheme

Various combinatorially non-local field theories are known to be renormalizable. Still, explicit calculations of amplitudes are very rare and restricted to matrix field theory. In this contribution I want to demonstrate how the BPHZ momentum scheme in terms of the Connes-Kreimer Hopf algebra applies to any combinatorially non-local field theory which is renormalizable. This algebraic method improves the understanding of known results in noncommutative field theory in its matrix formulation. Furthermore, I use it to provide new explicit perturbative calculations of amplitudes in tensorial field theories of rank r>2.

An explicit plethora of soliton solutions for a new microtubules transmission lines model: A fractional comparison

This paper introduces a new fractional electrical microtubules transmission lines model in the sense of Atangana–Baleanu and beta derivatives to comprehend nonlinear dynamics of the governing system. This structure possesses one of the most important parts in cellular process biology and fractional parameter incorporates the memory effects in microtubules. Also, microtubules are extremely beneficial in cell motility, signaling and intracellular transport. The new extended direct algebraic method is a compelling and persuasive integrating scheme to extract soliton solutions. The retrieved solutions include dark, bright and singular solitons. This model executes a prominent part in exhibiting the wave transmission in nonlinear systems. The novelty and advantage of the proposed method are portrayed by applying it to this model and its dynamical behavior is depicted by 3D and 2D plots. A comparative study of two fractional derivatives at distinct fractional parameter values and graphics of sensitivity analysis is also carried out in this paper.