Synchronous Sampling Research Articles

Synchronous sampling and clock recovery of internal oscillators for side channel analysis and fault injection

Measuring power consumption for side channel analysis typically uses an oscilloscope, which measures the data relative to an internal sample clock. By synchronizing the sampling clock to the clock of the target device, the sample rate requirements are considerably relaxed; the attack will succeed with a much lower sample rate. This work characterizes the performance of a synchronous sampling system attacking a modern microcontroller running a software AES implementation. This attack is characterized under four conditions: with a stable crystal oscillator-based clock, with a clock that is randomly varied between 3.9 and 13 MHz, with an internal oscillator that is randomly varied between 7.2 and 8.1 MHz, and with an internal oscillator that has slight random variation due to natural ‘drift’ in the oscillator. Traces captured with the synchronous sampling technique can be processed with a standard Differential Power Analysis style attack in all four cases, whereas when an oscilloscope is used only the stable oscillator setup is successful. This work also develops the hardware to recover the internal clock of a device which does not have an externally available clock. It is possible to implement this scheme in software only, allowing it to work with existing oscilloscope-based test environments. Performing the recovery in hardware allows the use of fault injection with excellent temporal stability relative to a sensitive event. This is demonstrated with a power glitch inserted into a microcontroller, where the glitch is triggered based on a signature in the measured power consumption.

Bearings-Only Tracking of Manoeuvring Targets Using Multiple Model Variable Rate Particle Filter with Differential Evolution

In standard target tracking, algorithms assume synchronous and identical sampling rate for measurement and state processes. Contrary to these methods particle filter is proposed with variable rate. These filters use a restricted number of states, and a Gamma distribution is applied at state arrival time so that the maneuvering targets could be tracked. Although this structure is capable of tracking a wide range of targets motion features using linear, curvilinear motion dynamics, it suffers from a basic weak point. It cannot estimate the position of targets in high maneuvering regions. Thus, multiple model variable rate particle filter (MM-VRPF) is utilized to overcome this shortage using various dynamic models. A weak point of a particle filter is a phenomenon called degeneracy that even exists in MM-VRPF structure. In this study, differential evolution method, is exploited to improve the mentioned method and a novel structure called multiple model variable rate particle filter with differential evolution (MM-VRPF with DE) is introduced. The simulation results of a bearing only tracking achieved from a maneuvering target, revealed that the proposed structure has better performance while it maintains advantages of variable rate structure.

Asynchronous Sampling Rate Conversion of Digital Audio Signal

At present, in the digital audio processing sampling rate is respectively 32 kHz, 44.1 kHz, 48 kHz [1]. Because of the different criteria, there is much inconvenience in the process of research. Therefore, the sampling rate converter is a must, between any two kinds of sampling rate. In synchronous sampling rate conversion, you can use decimation and interpolation for sampling rate conversion, but in the asynchronous sampling rate system, due to the different input clock pulse with the output clock pulse, the above method cannot achieve. Therefore we introduce the fractional delay filter sampling rate conversion. This article introduces the principle of the sampling rate conversion and the fractional delay filter based on Farrow structure. At last, we simulate asynchronous sampling rate conversion of audio signal through the MATLAB.

Research on A.C. Sampling Technique for the Electric Parameters Based on Embedded Linux and Frequency Self-Adapting

Directed at the traditional single chip microcomputer system which didn’t have the managing ability of the modern operating system, a technology of AC synchronization sampling was presented and implements which were based on embedded microprocessor S3C2410 and Linux real-time operating system kernel. The technology divided the sampling process into 2-part, frequency dynamic tracking and same-internal synchronization sampling .The multi-tasks, which process the different priorities, used to actualize sampling the signal and treating with the data. All tasks were scheduled by the preemptive Linux kernel. The technology has decreased the conflict between the precision and real-time property. The construction of hardware and software, method of constituting real-time operating system based on Linux kernel, signal frequency measuring, signal sampling and harmonic computing were introduced in detail.

Analysis of Input Phase for PLL in Dynamic Environment

In dynamic operating environment, it is one of key issues in the research field of electric energy metering that the accuracy of synchronous sampling signal based on phase locked technology. Because operating environment changes from steady state to dynamic, analytical description of PLL input signal becomes an urgent problem to be solved. In this paper, dynamic signal is analyzed mathematically by using zero-crossing detection theory, its phase expression is obtained, then mathematical equivalent conversion is made based on operation characteristics of PLL, its phase input equation is obtained, finally the correctness of the input equation is verified by Fourier transform method. This study lays the foundation for error analysis of electric energy metering system under dynamic condition.

Method based on independent component analysis for harmonic extraction from power system signals

This paper presents a new application of independent component analysis for harmonic component extraction from power system signals (voltage and current). The harmonics to be extracted can be time varying and the method does not require synchronous sampling, which means it is able to work in off-nominal frequency. The proposed method has shown to be simple in the operational stage. The method was tested using both simulated and real signals, and performance was evaluated using measures in both frequency and time domains. Results were compared with another method available in the literature.

Design of a Multichannel High Precision Instrument in Portable Data Acquisition

For the need of multi-channel simultaneous sampling in the modeling and identification of power system, a portable data acquisition system is introduced. It can sample multi-channel data simultaneously, and also have a mass data storage. The system is composed of data acquisition card and PC processing software. The C8051F410 MCU is the core of the data acquisition unit card. It not only provides multi-channel synchronous sampling, large storage capacity, easy to carry and low cost, but also can run offline, and bidirectional interaction with PC software. The data processing software is programmed by Visual Basic6.0. Its main function is sending sample orders and the sample data processing. It can store and process the sample data, also it can set the sampling parameters of the card. Through actual verification, the system is easy to use and meets the precision of requirement.

Advanced Applied Research of Smart Substation Based on Multi-Element Data

The real time synchronous sampling of large basic data information and the networking information sharing have laid necessary foundation for smart substation advanced application. The advanced application of smart substation is the multi-index optimization analysis and control strategy research which based on digitization of information transmission and networking of information sampling. This paper aimed at health state analysis and control strategy research of substation equipment and network environment, which based on the theory of multi-element data analysis and double network and double measuring and control.

Design and implementation of the optical fiber control and transmission module in multi-channel broadband digital receiver

An optical fiber control and transmission module is designed and realized based on Virtex-7 field programmable gata array (FPGA), which can be applied in multi-channel broadband digital receivers. The module consists of sampling data transfer submodule and multi-channel synchronous sampling control submodule. The sampling data transmission in 4× fiber link channel is realized with the self-defined transfer protocol. The measured maximum data rate is 4.97 Gbyte/s. By connecting coherent clocks to the transmitter and receiver endpoints and using the self-defined transfer protocol, multi-channel sampling control signals transferred in optical fibers can be received synchronously by each analog-to-digital converter (ADC) with high accuracy and strong anti-interference ability. The module designed in this paper has certain reference value in increasing the transmission bandwidth and the synchronous sampling accuracy of multi-channel broadband digital receivers.

A New Kind of Smart Dual DSP2812 Power Quality Monitor Based on Dedicated Users

Focus on the increasingly prominent problems of power quality of dedicated users, study on solving electric energy problems, especially for harmonic pollution, was essential. This paper to study the method of testing and calculating electric energy index, then designed hardware to monitor and analyze power quality measurement data. The hardware was developed base on dual DSP2812, which was very advanced digital signal processing chip, and the hardware utilized high precision instantaneous synchronous sampling chip MAX1324, extended RAM and FLASH, RS232 communication circuit, high capacity SD card storage circuit, etc. The dual DSP power quality smart meter was tested and applied in dedicated users and its reliability, practicability, availability and accuracy was authenticated. This smart meter also has advantages of easy to carry, low cost, high precision, easy to promote, etc. can effectively meet power quality management of dedicated users.

Comparison of approaches to time-synchronous sampling in wireless sensor networks

Time synchronization is required in many data acquisition applications for sensor networks. A large variety of time synchronization protocols for wireless sensor networks has been suggested. Yet, setting up a sensor network for synchronized data acquisition based on those algorithms is not a trivial task. This paper outlines different approaches to time synchronous sampling in wireless sensor networks. The approaches are implemented on a wireless sensor network. Experiments are done to compare the signal quality of the signals acquired with the different approaches in terms of frequency error, signal-to-noise ratio (SNR) and total-harmonic-distortion (THD). Furthermore, the approaches are compared in terms of the effort required for communication and implementation.

A Synchronous Sampling System of On-Line Monitoring for Long-Distance Cable Insulation Based on DSP and GPS

The induced voltage of the long-distance power cable will reach high value, so the metallic sheath of cable should be cross-linked to reduce the induced voltage. It is safe and economic enough but bring out problem of monitoring the situation of insulation. In order to solve the problem, a new method is provied and a monitoring system based on Digital Siganl Processor and Global Positioning System are designed. The composition of system has been introduced, includes the hardware and software design. The results show that the monitoring system can reflect the situation of cable insulation, and the mothod is proved to be validity and feasibility.

The Motor Temperature Rise Test System Based on Magnetic Powder Dynamometer

The motor temperature rise is an important indicator for the evaluation of motor performance and the development of motor testing system put forward higher requirements to data acquisition and processing. In view of this, the motor temperature rise test system based on the magnetic power dynamometer which acted as a load was studied. The overall structure and the software algorithm of the system were introduced. The existing synchronous sampling method was put into use in data acquisition system of the motor temperature rise test so that it can automatically test the motor temperature rise. Combining with the instance, proves the accuracy of this method. This method has the superiority of reducing errors and improving accuracy by combining with the instance.

The Design of Multichannel Marine Seismic Acquisition Unit Based on ADS1282

For marine seismic data acquisition needs,a multichannel marine seismic data acquisition unit was designed,which used the 32-bit analog-to-digital ADS1282 as a core and Field programmable gate array (FPGA) as the acquisition controller.The unit can achieve multichannel seismic data sampling and transmission functions.The design fully used with the design ADS1282 chip integration,with the corresponding anti-jamming measures,not only simplified the circuit design,but also ensured the quality of signal acquisition and system stability.the design used FPGA to realize a multichannel hydrophone signal synchronization sampling.

A New Portable Harmonic Analyzer Based on MSP430

In this paper, a new portable digital instrument is developed to measure the frequency, rms voltage, rms current and harmonic of power grid. Three phase voltage and current are sensed with precise transformer and then processed by signal conditioning unit before sampling. Synchronous AC sampling technique is introduced to avoid leakage effect of FFT. Consequently, frequency estimation, rms measurement and harmonic estimation are achieved based on MSP430. The experiment results indicate that this analyzer provides accurate frequency estimates with error in the range of 0.001Hz and amplitude estimates with error in the range of 0.1%, which can meet the need of offline application.

On-line Monitoring System of Capacitive Equipment Dielectric Loss

To ensure capacitive equipment working safely and reliably, an on-line monitoring system of capacitive equipment dielectric loss was developed. The insulation situation was estimated accurately through long-distance synchronous sampling (using IRIG-B code synchronous clock), seamless connection of data between devices using Intelligent Electronic Device (IED), communication following IEC61850 protocol, and data analysis (using fault diagnosis algorithm). Running results showed that the system not only can accurately monitor the information, such as leakage current, dielectric loss, and equivalent capacitance, which reflect the working condition of capacitive equipment, but also can transmit data to the on-line monitoring data center through the IEC61850 protocol. The operating data, monitoring on CVTs in 330kV substation, showed the great improvement of this system on credibility, accuracy, and stability. What’s more, it also proved the great value of using and promoting this system. DOI : http://dx.doi.org/10.11591/telkomnika.v12i6.4866

Transmission-Line Fault Analysis Using Synchronized Sampling

An automated analysis approach, which can automatically characterize fault and subsequent relay operation, is the focus of this paper. It utilizes synchronized samples captured during transients from both ends of the transmission line to detect, classify, and locate transmission-line faults and can verify that the tripped line has indeed experienced a fault. The proposed method is tested for several faults simulated on an IEEE 118-bus test system and it has been concluded that it can detect and classify a fault using prefault and postfault recorded samples within 7 ms of fault inception and can accurately locate a fault with 3% accuracy. This time response performance is highly desirable since with the increasing use of modern circuit breakers, which can open the faulty line in less than two cycles, the time window of the captured waveforms is significantly reduced due to the unavailability of measurement signals after breakers open.

Wind turbine condition monitoring

Wind turbine condition monitoring

Synchronization sampling method based on delta-sigma analog-digital converter for underwater towed array system

Synchronization sampling is very important in underwater towed array system where every acquisition node (AN) samples analog signals by its own analog-digital converter (ADC). In this paper, a simple and effective synchronization sampling method is proposed to ensure synchronized operation among different ANs of the underwater towed array system. We first present a master-slave synchronization sampling model, and then design a high accuracy phase-locked loop to synchronize all delta-sigma ADCs to a reference clock. However, when the master-slave synchronization sampling model is used, both the time-delay (TD) of messages traveling along the wired transmission medium and the jitter of the clocks will bring out synchronization sampling error (SSE). Therefore, a simple method is proposed to estimate and compensate the TD of the messages transmission, and then another effective method is presented to overcome the SSE caused by the jitter of the clocks. An experimental system with three ANs is set up, and the related experimental results verify the validity of the synchronization sampling method proposed in this paper.

A Harmonic Analysis Algorithm Based on Tracking the Fundamental

In the FFT harmonic detection, the detection accuracy is reduced because of asynchronicity between the sampling frequency and the signal of base wave frequency. In order to improve the detection accuracy, a harmonic detection algorithm based on the fundamental frequency tracking is proposed. Firstly windowed interpolation FFT algorithm is used to detect signal of base wave frequency, then the fundamental frequency is tracked and the sampling frequency is dynamically adjusted. Finally, the signal sequence is obtained by quasi synchronous sampling with frequency multiplication technology, and amplitudes and phases of the signal are received with the FFT analysis. Because the sampling frequency synchronization error and the influence of frequency spectrum leakage are reduced, the detection accuracy is improved. This algorithm is applied to the electrical energy harmonic analysis with simple implementation and high accuracy.