D.E. Manolakis

Efficient solution and performance analysis of 3-D position estimation by trilateration

A new exact, explicit, and computationally efficient solution for three-dimensional (3-D) position estimation based on range measurements from three stations is proposed. The simple polynomial-type form of the new algorithm facilitates the performance analysis. Formulae are provided for both the variance and the bias of the position estimates. The systematic error is a joint effect of both the measurement noise and the system nonlinearity and its magnitude cannot be ignored if highly accurate localization is required. Performance evaluation results are presented for various conditions.

Design of a fuzzy system for living space thermal-comfort regulation

The present paper describes the design of a living space comfort regulator using fuzzy logic. Comfort is a fuzzy concept, different for different people and depending on the work done in the space. The paper describes the structure of the system, the available measurements and the available actuators, the measurement fuzzification process and the defuzzification method. Particular attention is paid to the proper selection of the rules in the knowledge base and the design of the inference engine. Finally the system is tested, and shows satisfactory performance. General design guidelines are given, including the case of spaces having different actuators.

Thermal-comfort degradation by a visual comfort fuzzy-reasoning machine under natural ventilation

Fuzzy reasoning is used for visual comfort control in buildings. Natural ventilation is used to save energy and contribute to the achievement of thermal comfort. The present paper investigates the impact of natural ventilation on the thermal-comfort index, assuming the implementation of fuzzy reasoning for visual comfort control. Mathematical models are used to calculate the outdoor climate, the indoor climate and the thermal-comfort index. Finally, a fuzzy-reasoning expert-system, using a linguistic type algorithm, is presented.

Computation of aircraft geometric height under radar surveillance

A radar system for geometric height estimation of civil aircraft is described. The system consists of one standard or mode S secondary surveillance radar (SSR) and one omnidirectional antenna sited away from SSR under an airplane. The geometric height is derived by trilateration. Systematic errors are compensated for by deriving the profile of the effect on height measurements of the bias in range measurements. A curve-fitting technique is then used, which estimates both the geometric height and any non-zero systematic errors. >

Effect in range difference position estimation due to stations' position errors

This work addresses the subject of systematic errors caused by using incorrect coordinates for the sites where the stations are located in a three-dimensional aircraft position estimation system, composed of one transmitter/receiver and three receiving stations. The differences in the aircraft ranges from the receiving stations are used to derive the position estimate. A general analytic expression is developed to assess the error resulting from using erroneous coordinates for the receivers location. Evaluation has been performed for certain representative conditions.

Computation of aircraft geometric height under radar surveillance for non-level flights

A new aircraft geometric height computation system based on a secondary surveillance radar (SSR) and an omni-directionat radar has recently been presented. One interesting aspect of this system is that it employs a simple analytical method to estimate and compensate for observable systematic errors, mainly created by the aircraft transponder. Herein, this off-line processing algorithm is extended to cover non-level flights by augmenting the aircraft vertical motion model.

Kronecker Product Based Second Order Approximation of Mean Value and Covariance Matrix in Nonlinear Transformations

This paper derives new formulae for the approximations of the mean value and the covariance matrix of a random vector which is derived as a nonlinear transformation of another random vector. Towards this purpose, it is first proposed to formulate the Taylor series expansion by using Kronecker product operators along with partial derivatives block matrices. This formulation facilitates the mathematical manipulation of higher order terms in multidimensional systems. The final expressions for the mean value and covariance matrix are simple in block matrix notation, convenient and easy to implement. The analytical expressions are evaluated and verified in a typical nonlinear transformation faced in navigation systems.

Inherent bias assessment in height computation employing mixed-type radar data

The objective here is the analysis of a systematic error inherently existing in aircraft geometric height monitoring under radar surveillance. This error is caused by the nonlinear processing of noisy measurements. The geometric height system under investigation uses mixed-type radar data, since the height is computed by referring range raw measurements to horizontal trajectory smoothed data. >

A fuzzy rule-based approach to achieve visual comfort conditions

In this paper, rule based controller is used to achieve visual comfort in buildings. The objective of this paper is to investigate the fuzzification process and develop a working tuning strategy. The performance of the resultant self-tuning rule base controller is tested against input perturbations and set point changes. The advantages of the proposed system are clarified and compared by the classical control systems.

Comment on "Content-Based Event Retrieval Using Semantic Scene Interpretation for Automated Traffic Surveillance

This contribution notes that some equations concerning the Kalman filter proposed in the cited paper are not correct.