Reza Jazar - Academia.edu (original) (raw)

Papers by Reza Jazar

This paper presents a new robust adaptive Gaussian mixture sigma-point particle filter by adoptin... more This paper presents a new robust adaptive Gaussian mixture sigma-point particle filter by adopting the concept of robust adaptive estimation to the Gaussian mixture sigma-point particle filter. This method approximates state mean and covariance via Sigma-point transformation combined with new available measurement information. It enables the estimations of state mean and covariance to be adjusted via the equivalent weight function and adaptive factor, thus restraining the disturbances of singular measurements and kinematic model noise. It can also obtain efficient predict prior and posterior density functions via Gaussian mixture approximation to improve the filtering accuracy for nonlinear and non-Gaussian systems. Simulation results and comparison analysis demonstrate the proposed method can effectively restrain the disturbances of abnormal measurements and kinematic model noise on state estimate, leading to improved estimation accuracy.

Smart Innovation, Systems and Technologies, 2016

Passengers in autonomous vehicles are prone to motion sickness. Receding horizon control of pure ... more Passengers in autonomous vehicles are prone to motion sickness. Receding horizon control of pure pursuit tracking algorithms has been shown to improve path tracking performance. In this paper we present a numerical study on the effect of the receding horizon pure pursuit controller on passenger comfort. Three standard cases at the different speeds are utilized to compare the effect of traditional and receding horizon pure pursuit control on passenger comfort. The results show improvements in passenger comfort at higher speeds using receding horizon control and that path continuity is more influential that optimal tracking control.

IEEE Transactions on Intelligent Transportation Systems, 2015

This paper presents a motion planner tailored for particular requirements for robotic car navigat... more This paper presents a motion planner tailored for particular requirements for robotic car navigation. We leverage B-spline curve properties to include vehicle's constraint requirements, thus lowering the search dimensionality. An algorithm, which combines competent exploratory nature of the randomized search methods with vector-valued parameterization steering, is developed here. Vehicle's limitations, along with obstacle's constraints, are satisfied without being hindered by numerical integration and control space discretization of traditional randomized kinodynamic planners. We rely on newly developed theoretical underpinnings to overcome performance issues in rapidly exploring random tree (RRT) solutions. Rigorous simulations and analysis demonstrate that this new approach outperforms recently proposed planners by using an efficient bidirectional RRT-based search, by maintaining continuous state and control spaces, and generating C2 continuous paths, which are realistic inputs suited for mobile robotic applications and passenger vehicles.

Journal of Physics: Conference Series, 2006

Energy Procedia

Abstract This paper examines the how the South Asian countries are addressing their energy defici... more Abstract This paper examines the how the South Asian countries are addressing their energy deficiency as the capacity to refine imported crude oil is limited except India. India has developed substantial refining capacity (247.6 million tons per annum) compared to Pakistan (18.8 mtpa) and Bangladesh (1.5 mtpa). India’s refining capacity is being currently utilized nearly 100%. Having no local refining capacity, Nepal and Bhutan import refined petroleum products entirely mainly from India. The demand for refined petroleum products in Bangladesh outstripped the quantity produced by the country’s single aged oil refinery over 3 times. Similar problem is faced by Pakistan. This paper provides an analytical framework based on the data collected from the region and argues that a regional energy trade will create a mutually beneficial platform for effective utilisation of natural resources which will increase reliability of power supply, build economies of scale, enable mutual support during contingencies, transform sectors on a large scale and contribute to economic growth. This trading platform will promote market integration in energy (oil, gas coal) and energy-related goods and services.

Thin-Walled Structures, 2016

In a vehicular crash, a higher level of energy absorption in the frontal structures of the vehicl... more In a vehicular crash, a higher level of energy absorption in the frontal structures of the vehicle leads to less transferred energy to the passengers and less possibility for injury. S-shaped front rails, also known as S-rails, are one of the main structural elements and energy absorbers in the body of a vehicle. To improve the safety of passengers, the S-rail design should be optimized to absorb higher levels of energy in a frontal crash. In this study, the impact of tapering S-rails on the energy absorption is investigated. Two S-rails, one without internal diagonal reinforcement (type-A) and one with internal diagonal reinforcement (type-B), are both tapered with 20 different tapering ratios ranging from 110% to 300% in 10% increments. All of the S-rail models are subjected to static and dynamic loading conditions. Finite element analysis is used to assess the effectiveness of tapering S-rails by investigating the energy absorption (EA) and specific energy absorption (SEA) variations. An equation is developed to verify the numerical results. In this study, the reinforcing and tapering S-rails are shown to improve the EA and SEA under both static and dynamic loading conditions. By combining reinforcing and tapering techniques, S-rails showed a noticeable improvement in SEA of more than 300% in the static loading condition and an improvement of 275% in the dynamic loading condition.

International Journal of Non-linear Mechanics, 1998

A massless cantilever beam with a lumped mass attached to its free end while being excited harmon... more A massless cantilever beam with a lumped mass attached to its free end while being excited harmonically at the base is fully investigated. The derived equation of vibrating motion is found to be a non-linear parametric ordinary differential equation, having no closed form solution for it. We have, therefore, established the sufficient conditions for the existence of periodic oscillatory behavior

The Journal of the Acoustical Society of America

Fault identification using the emitted mechanical noise is becoming an attractive field of resear... more Fault identification using the emitted mechanical noise is becoming an attractive field of research in a variety of industries. It is essential to rank acoustic feature integration functions on their efficiency to classify different types of sound for conducting a fault diagnosis. The Mel frequency cepstral coefficient (MFCC) method was used to obtain various acoustic feature sets in the current study. MFCCs represent the audio signal power spectrum and capture the timbral information of sounds. The objective of this study is to introduce a method for the selection of statistical indicators to integrate the MFCC feature sets. Two purpose-built audio datasets for squeak and rattle were created for the study. Data were collected experimentally to investigate the feature sets of 256 recordings from 8 different rattle classes and 144 recordings from 12 different squeak classes. The support vector machine method was used to evaluate the classifier accuracy with individual feature sets. The outcome of this study shows the best performing statistical feature sets for the squeak and rattle audio datasets. The method discussed in this pilot study is to be adapted to the development of a vehicle faulty sound recognition algorithm. V

Autodriver algorithm Anna Bourmistrova, Milan Simic, Reza Hoseinnezhad, Reza N. Jazar The autodri... more Autodriver algorithm Anna Bourmistrova, Milan Simic, Reza Hoseinnezhad, Reza N. Jazar The autodriver algorithm is an intelligent method to eliminate the need of steering by a driver on a well-defined road. The proposed method performs best on a four-wheel steering (4WS) vehicle, though it is also applicable to two-wheel-steering (TWS) vehicles. The algorithm is based on coinciding the actual vehicle center of rotation and road center of curvature, by adjusting the kinematic center of rotation. The road center of curvature is assumed prior information for a given road, while the dynamic center of rotation is the output of dynamic equations of motion of the vehicle using steering angle and velocity measurements as inputs. We use kinematic condition of steering to set the steering angles in such a way that the kinematic center of rotation of the vehicle sits at a desired point. At low speeds the ideal and actual paths of the vehicle are very close. With increase of forward speed the ro...

Volume 1: 20th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C, 2005

ABSTRACT

Communications in Nonlinear Science and Numerical Simulation, 2005

A theorem is proved to show that the third order differential equation x‴+f(t,x,x′,x″)=0 has nont... more A theorem is proved to show that the third order differential equation x‴+f(t,x,x′,x″)=0 has nontrivial solutions characterized by x′(0)=x′(τ)=0 when x,x′,x″ and f(t,x,x′,x″) are bounded. A second condition is introduced to prove the existence of periodic solution for this equation. It is shown that the equation has a τ-periodic solution if f(t,x,x′,x″) is an even function with respect to x′. The existence and periodicity conditions would be applied to third order systems such as viscoelastic mechanical vibration isolator system. The concepts of Green’s function and the Schauder’s fixed-point theorem have been used for proving the third-order-existence theorem.

In this chapter, we examine a linear, one degree-of-freedom, base excited vibration isolator syst... more In this chapter, we examine a linear, one degree-of-freedom, base excited vibration isolator system as the simplest model for a vibration isolator and vehicle suspension. Based on a root mean square (RMS) optimization method, we develop a design chart to determine the optimal damper and spring for the best vibration isolation and ride comfort.

Applied Mechanics and Materials, 2013

Developing algorithms that allow robots to independently navigate unknown environments is a widel... more Developing algorithms that allow robots to independently navigate unknown environments is a widely researched area of robotics. The potential for autonomous mobile robots use, in industrial and military applications, is boundless. Path planning entails computing a collision free path from a robots current position to a desired target. The problem of path planning for these robots remains underdeveloped. Computational complexity, path optimization and robustness are some of the issues that arise. Current algorithms do not generate general solutions for different situations and require user experience and optimization. Classical algorithms are computationally extensive. This reduces the possibility of their use in real time applications. Additionally, classical algorithms do not allow for any control over attributes of the generated path. A new roadmap path planning algorithm is proposed in this paper. This method generates waypoints, through which the robot can avoid obstacles and re...

This chapter presents a B-spline path synthesis approach for nonholonomic car-like vehicles. Rece... more This chapter presents a B-spline path synthesis approach for nonholonomic car-like vehicles. Recent findings in robotic research suggest that C2 continuity is a realistic representation of robotic paths. A novel solution that guarantees C2 parametric continuity for a cubic path, whilst satisfying kinodynamic constraints imposed on the vehicle, is proposed here. This chapter investigates path synthesis for front wheel steered vehicles. It is required to generate paths with continuous, bounded curvatures. Our approach is based on clamped B-spline curves. We leverage the curves’ properties to resolve the considered problem. In order to ensure continuity, a single curve segment is utilized for the entire path. Path curvature is formulated with respect to the B-spline curve parameters. This approach mimics human operating and minimizes disturbances on passengers. We present here a method of curvature estimation that is more accurate and time efficient than previously published solutions....

The autodriver algorithm was introduced as a path-following algorithm for autonomous vehicles, wh... more The autodriver algorithm was introduced as a path-following algorithm for autonomous vehicles, which uses road geometry data and planar vehicle dynamics. In this paper, the autodriver algorithm is improved according to practical implications, and a more realistic vehicle model (roll mode) is used, which considers roll degree of freedom in addition to a planar motion. A Ghost-Car path-following approach is introduced to define the desired location of the car at every instance. Key steady-state characteristics of turning vehicles, namely the curvature, yaw rate, and side-slip responses, are discussed and used to construct a feed-forward component of a path-following controller based on the autodriver algorithm. Feedback control loops are designed and applied to minimise transient errors between the road and vehicle positions. Finally, simulations are performed to analyse the pathfollowing performance of the proposed scheme. The results show promising performance of the controller both...

By modelling a four-wheel vehicle as a bicycle, it has been suggested (Olley 1934) that if the ra... more By modelling a four-wheel vehicle as a bicycle, it has been suggested (Olley 1934) that if the radius of gyration, r, in pitch is equal to the multiplication of the distance from the center of gravity of the front, a, and rear, b, wheels of the car (\( r^{2} = a \cdot b \)), the bounce center of the vehicle will be located at one spring and the pitch center on the other spring of a bicycle car model.

Materials

To produce high quality and low cost carbon fiber-based composites, the optimization of the produ... more To produce high quality and low cost carbon fiber-based composites, the optimization of the production process of carbon fiber and its properties is one of the main keys. The stabilization process is the most important step in carbon fiber production that consumes a large amount of energy and its optimization can reduce the cost to a large extent. In this study, two intelligent optimization techniques, namely Support Vector Regression (SVR) and Artificial Neural Network (ANN), were studied and compared, with a limited dataset obtained to predict physical property (density) of oxidative stabilized PAN fiber (OPF) in the second zone of a stabilization oven within a carbon fiber production line. The results were then used to optimize the energy consumption in the process. The case study can be beneficial to chemical industries involving carbon fiber manufacturing, for assessing and optimizing different stabilization process conditions at large.