Design Method of High-Order Kalman Filter for Strong Nonlinear System Based on Kronecker Product Transform

In this paper, a novel design idea of high-order Kalman filter based on Kronecker product transform is proposed for a class of strong nonlinear stochastic dynamic systems. Firstly, those augmenting systems are modeled with help of the Kronecker product without system noise. Secondly, the augmented system errors are illustratively charactered by Gaussian white noise. Thirdly, at the expanded space a creative high-order Kalman filter is delicately designed, which consists of high-order Taylor expansion, introducing magical intermediate variables, representing linear systems converted from strongly nonlinear systems, designing Kalman filter, etc. The performance of the proposed filter will be much better than one of EKF, because it uses more information than EKF. Finally, its promise is verified through commonly used digital simulation examples.

An Enhanced Multi-frequency Distorted Born Iterative Method for Ultrasound Tomography based on Fundamental Tone and Overtones

Conventional Distorted Born Iterative Method (DBIM) using single frequency has low resolution and is prone to creating images with high-contrast subjects. We propose a productive frequency combination method to better result in tomographic ultrasound imaging based on the multi-frequency technique. This study uses the natural mechanism of emitting oscillators' frequencies and uses these frequencies for imaging in iterations. We use a fundamental tone (i.e., the starting frequency f0) for the first iteration in DBIM, then consecutively use its overtones for the next ones. The digital simulation scenarios are tested with other multi-frequency approaches to prove our method's feasibility. We performed 57 different simulation scenarios on the use of multi-frequency information for the DBIM method. As a result, the proposed method for the smallest normalization error (RRE = 0.757). The proposed method's imaging time is not significantly longer than the way of using single frequency information.

APPLICATION OF DIGITAL STRUCTURE SIMULATION AS A TOOL FOR THE EXPLORATION OF WIDE SPAN STRUCTURE IDEAS

Review on structure behaviour and visual appearance of a building is needed in generating creativity in the making of an architectural design. The use of any specific structure software will facilitate this in the process. This research aims to prove the effectiveness with which designers can compose alternative forms of architectural appearance through the use of the software. One of the tools in the creative process used in the exploration of 2-dimensional frame structures is DR FRAME. The observations were carried in the Structure and Construction IV Studio at Itenas Architecture Study Program Bandung through a digital simulation using DR. FRAME software demo version. Several students are invited to explore various forms of wide-span truss structures at the level of unified integration. The results through the program execution show various diagrams which can be implemented in the design of the form and the type of structural components. DR.FRAME software enriches ideas in the wide-span structure design which provides an understanding of the relationship between structural behaviour and the appearance of architectural design. The use of other supporting software is supposed to be applied as an alternative search for various structural design ideas for architecture students

Lumped-Circuits Model of Lossless Transmission Lines and Its Numerical Characteristics

Aiming at the lumped-circuits model of the lossless transmission line in the digital simulation, the article discusses and analyzes the unit step response generation of the lumped-circuits model by comparing the numerical simulation results of the implicit trapezoidal method, the implicit Euler method, and a multi-step formula. The root cause of numerical oscillations pointed out that using the L-stable numerical algorithm to indirectly simulate the dynamic response of the lumped-circuits model is a numerical method that does not truly reflect the original model, but it can directly reflect the true dynamic response of the lossless transmission line. In this study, a method for determining the chained number in the digital simulation of a lumped-circuits model is given. The simulation results prove the effectiveness of the method.

Embedding an Electrical System Real-Time Simulator with Floating-Point Arithmetic in a Field Programmable Gate Array

Real-Time Digital Simulation (RTDS) is a powerful tool in modeling and analyzing electrical and drive systems because it provides an efficient and accurate process. There are several hardware devices for this type of simulation; however, their high costs have led to the increasing use of more affordable and reconfigurable technologies. In this context, many logic blocks and storage elements make the Field Programmable Gate Array (FPGA) an ideal device to perform RTDS. This work proposes a technique to embed a real-time digital simulator in an FPGA through Hardware Description Language (HDL) since it provides liberty in the architecture choice and no dependency on commercial ready-made hardware–software packages. The approach proposed focuses on system design developing with expression tree graph, synthesizing and verifying, prioritizing the performance and design accuracy concerning area and power consumption. Thus, the result acquisition occurs at a time step considered in real-time. A simulation of a direct current (DC) motor speed control has been incorporated into this work as an example of application, which includes the embedding and simulation of the electric machine and its drive system. Performance tests have shown that the developed simulator is real-time and makes possible realistic analysis of the interaction between the plant and its control. In addition, an idea of the hardware requirement for real-time simulation is proposed based on the number of mathematical operations.

Performance test of small-current grounding line selection device based on the real-time digital simulation system

Single phase grounding fault is the most common fault type in small-current grounding distribution network, but the small-current grounding line selection device put into operation on site is often difficult to meet the application requirements, affecting the rapid and accurate treatment of grounding fault. Considering that there are many small-current grounding line selection manufacturers and various device forms, it is difficult to intuitively evaluate the line selection performance of different devices and make horizontal comparison, and there is no supporting basis for the selection and application of on-site line selection devices. Therefore, based on the real-time digital simulation system (RTDS), this paper establishes a test platform for small-current grounding line selection device. Based on the constructed test platform, four line selection devices form different manufacturers are tested in parallel, the performance of the devices is compared, and the influencing factors affecting the accuracy of line selection results are analyzed. The conclusions of this paper can provide strong support for the pilot application of small-current line selection devices.

A Digital-Simulation Model for a Full-Polarized Microwave Radiometer System and Its Calibration

A digital-correlation full-polarized microwave radiometer is an important passive remote sensor, as it can obtain the amplitude and phase information of an electromagnetic wave at the same time. It is widely used in the measurement of sea surface wind speed and direction. Its configuration is complicated, so the error analysis of the instrument is often difficult. This paper presents a full-polarized radiometer system model that can be used to analyze various errors, which include input signal models and a full-polarized radiometer (receiver) model. The input signal models are generated by WGN (white Gaussian noise), and the full-polarized radiometer model consists of an RF front-end model and digital back-end model. The calibration matrix is obtained by solving the overdetermined equations, and the output voltage is converted into Stokes brightness temperature through the calibration matrix. Then, we use the four Stokes parameters to analyze the sensitivity, linearity, and calibration residuals, from which the simulation model is validated. Finally, two examples of error analysis, including gain imbalance and quantization error, are given through a simulation model. In general, the simulation model proposed in this paper has good accuracy and can play an important role in the error analysis and pre-development of the fully polarized radiometer.

Kinematic model of the suspension of an electric car

The purpose of the work considered in this article is to develop approaches and methods for designing an electric vehicle from the concept phase to production based on the use of digital simulation. In this study, calculations were performed using the calculation of the kinematic model of the electric car suspension and CAE. Based on the results of the calculations and their compliance with the matrix of targets and resource constraints, the geometry of the suspension parts was changed during the study. For each of the iterations of the geometry, the types and materials were selected for the subsequent production of electric car suspension parts. The application of the above-mentioned approach from the earliest stages of work allowed us not only to achieve the required criteria for the mechanical characteristics of the structure, but also to comply with the conditions for reducing the development time, the cost of production and improving its quality.