Jinsong Du

Overview of Micro-Force Sensing Methods

At present, reliable micro-force sensing is one of the most important research for micromanipulation and micro-assembly. Six kinds of methods to detect micro-force are described in this paper. Analysis of the basic principle and detection accuracy of each sensing method, and applications in micro-assembly and micromanipulation are briefly introduced. The purpose of this paper is to be useful to provide some references for scholars engaging in the micro-force sensing, which in turn promotes automatic processing level of micro-assembly and micromanipulation to reliably manufacture micro devices of high quality.

An adaptive interacting multiple model for vehicle target tracking method

In the field of traffic safety vehicle target tracking prediction as the background, this paper proposes an adaptive interacting multiple model tracking algorithm. According to the field of transportation vehicle movement state characteristics, based on the uniform (CV) and uniformly accelerated motion (CA) model, based on new information structure model of motion of the likelihood function, online adaptive adjustment model of the noise variance and the Markov matrix, realization of maneuvering target movement model and model set adaptation, not only improved IMM algorithm for tracking accuracy, and enhances the real-time performance of system, the simulation results show that, the algorithm for tracking precision compared to the traditional IMM method has bigger improvement.

High bandwidth memory interface design based on DDR3 SDRAM and FPGA

This work presented the high bandwidth memory interface design based on DDR3 SDRAM using external memory IP core provided by FPGA devices. The structure and configuration of IP core was introduced and the simulation on soft and hard IP was carried out with the access controller designed. The maximum transmission bandwidth of the memory interface based on the soft and hard IP respectively reached 19.2Gbps and 25.6Gbps. Finally, the reliability of the interface controller was verified by downloading the program to the DAQ board and observing the internal signals.

Simulation and Analysis of DDR3 Bus Based on Fly-By Topology with Cadence

For the requirements of different bus signals from high speed PCB with DDR3 components based on fly-by topology structure, coping strategies have been proposed respectively. For the address or command bus, a leveling-free strategy has been proposed. It shows that the phase difference can be nearly zero through reasonable constraints on PCB design. The strategy was applied to the clock bus and achieved good performance, combining with the rules of signal integrity. For the data bus, the timing sequence on source synchronous has been analyzed and the time margin was calculated. The reasonability of the design was verified through the simulation result with Cadence.

Design and Realization of Universal Radar Signal Processing Software

As parallel signal processing tasks are more and more widely used, a universal, efficient and flexible radar signal processing software is urgently needed in the field of radar signal processing. Traditional development of parallel signal processing needs a large number of specialized programs, and must couple with the hardware platform. Therefore, the cost of development and promotion is quite large. The universal radar signal processing software designed in this paper is an integrated development environment to achieve fully graphical, generalized, and modularized development. The software is able to automatically generate codes. This function replaces traditional developing method that needs designers write a large number of programs. The above function significantly shortens the developing cycle and improves the developing efficiency. Besides, the software is of powerful debugging features. Furthermore, the software has excellent generalization and expansibility for hardware platform.

Radar Detection of Fluctuating Targets under Heavy-Tailed Clutter Using Track-Before-Detect

This paper considers the detection of fluctuating targets in heavy-tailed clutter through the use of dynamic programming based on track-before-detect (DP–TBD) in radar systems. The clutter is modeled in terms of K-distribution, which can be widely used to describe non-Gaussian clutter received from high-resolution radars and radars working at small grazing angles. Swerling type 1 is considered to describe the target fluctuation between scans. Conventional TBD techniques suffer from significant performance loss in heavy-tailed environments due to the more frequent occurrences of target-like outliers. In this paper, we resort to a DP–TBD algorithm based on prior information, which can enhance the detection performance by using the environment and target fluctuating information during the integration process of TBD. Under non-Gaussian background, the expressions of the likelihood ratio merit function for Swerling type 1 targets are derived first. However, the closed-form of the merit function is difficult to obtain. In order to reduce the complexity of evaluating the merit function and the computational load, an efficient approximation method as well as a two-stage detection approach is proposed and used in the integration process. Finally, several numerical simulations of the new strategy and the comparisons are presented to verify that the proposed algorithm can improve the detection performance, especially for fluctuating targets in heavy-tailed clutter.

Multi-Target Detection Method Based on Variable Carrier Frequency Chirp Sequence

Continuous waveform (CW) radar is widely used in intelligent transportation systems, vehicle assisted driving, and other fields because of its simple structure, low cost and high integration. There are several waveforms which have been developed in the last years. The chirp sequence waveform has the ability to extract the range and velocity parameters of multiple targets. However, conventional chirp sequence waveforms suffer from the Doppler ambiguity problem. This paper proposes a new waveform that follows the practical application requirements, high precision requirements, and low system complexity requirements. The new waveform consists of two chirp sequences, which are intertwined to each other. Each chirp signal has the same frequency modulation, the same bandwidth and the same chirp duration. The carrier frequencies are different and there is a frequency shift which is large enough to ensure that the Doppler frequencies for the same moving target are different. According to the sign and numerical relationship of the Doppler frequencies (possibly frequency aliasing), the Doppler frequency ambiguity problem is solved in eight cases. Theoretical analysis and simulation results verify that the new radar waveform is capable of measuring range and radial velocity simultaneously and unambiguously, with high accuracy and resolution even in multi-target situations.

Imaging reconstruction with the compensation of inhomogeneous microwave energy distribution

Microwave induced thermoacoustic tomography is a method for noninvasive, high contrast, high resolution and cost effective breast cancer detection. The thermoacoustic wave is received by the ultrasonic sensor after microwave radiation. The reconstructed image reflects the electromagnetic energy distribution of breast cancer, so it may serve as a routine detection of early stage breast cancer. Due to the heterogeneity of pulsed microwave radiation energy, it is essential to blend it into the reconstructed acoustic model of breast environment. In the present study, simulation and experiment have been used for pulsed microwave energy spatial distribution investigation. Obtained results suggest that it is feasible to detect microwave energy spatial distribution with the thermoacoustic imaging, which has paved the way to solve the inhomogeneous microwave energy problem in the thermoacoustic tomography.

The IMM tracking algorithm for maneuvering target with adaptive Markov transition probability matrix

This paper proposes an interacting multi-model (IMM) tracking algorithm based on the adaptive Markov transition probability matrix, which can be utilized in radar systems for maneuvering target tracking. The algorithm constructs likelihood ratio function of motion model, and presents an adaptive Markov transition probabilities calculated thought. Base on “new information” structure model of motion of the likelihood function, tracking system can online adjustment model of the noise variance and the Markov matrix adaptively. The Monte Carlo simulation is carried out by software, which shows that the tracking performance of the algorithm is superior to the traditional method of IMM.

Improved multi-target radar TBD algorithm

Considering radar detection for multi-target recognition, a track before detect (TBD) algorithm based on Hough transform is adopted for identifying and tracking multi-target radar. By increasing the dimensions of the target characteristic parameters, the target detection and track accuracy is increased. Also, by multilevel filtering processing, the diverging points of the echo signal are condensed, which improves the performance of identifying and tracking multiple targets. Simulation results show that compared with traditional TBD algorithms, the presented algorithm has better performance in the aspects of multi-target tracking, detecting and distinguishing. c 1990-2011 Beijing Institute of Aerospace Information.