This paper presents an easy and a robust sensor fault detection and isolation (FDI) and fault tolerant control (FTC) of a single phase PWM rectifier for electrical railway traction application. Catenary current sensor and dc link voltage sensor failures are considered. The FDI method is based on observers and residual generation. The different FDI algorithm steps allow a good detection and isolation of the sensor fault and identify the faulty sensor. The reconfiguration strategy consists of two steps with open loop control and closed loop control working. Simulation results are presented to illustrate the good performance of the FTC procedure. Experimental results are also presented to show the effectiveness of the proposed FDI and FTC algorithms and good performances of the rectifier after the reconfiguration.

State Observer-Based Sensor Fault Detection and Isolation, and Fault Tolerant Control of a Single-Phase PWM Rectifier for Electric Railway Traction

This paper gives a review of sensors, methods, and algorithms available for the measurement of angular acceleration. The emphasis is in delay-sensitive, real-time applications. Although the angular acceleration can be measured indirectly using either a rotating angle sensor or a velocity sensor, the noise-amplification problem related to the differentiation process has motivated the efforts to develop transducers for direct sensing of angular acceleration. Direct measuring of linear acceleration is widely in everyday use, but the angular acceleration sensors, particularly those with unlimited rotation angle, can still be considered as emerging devices. Consequently, there exist two principal challenges for the research and development community: to develop economical and accurate angular accelerometers with unlimited rotation range, and to create wideband indirect techniques with small lag and high signal-to-error ratio.

Angular acceleration measurement: a review

Additional delay is an unavoidable drawback of conventional filters used frequently in industrial electronics. This delay is particularly harmful if the filtered primary signal is to be used for time-critical feedback or synchronization purposes. Therefore, predictive signal processing methods can offer significant advantages for these real-time applications. Polynomial predictive filters are specified without explicit passbands and stopbands, and they are behaving delaylessly or predictively for smoothly varying signal components. The degree of smoothness of the incoming signal sets the requirements for the applied filtering scheme and its parameters. Smoothness of a signal is a fuzzy and application-specific concept: the degree of smoothness depends on the ratio of the bandwidth of the primary signal and the applied sampling rate, as well as the noise component. In this paper, the authors review the most important polynomial predictive filtering methods and algorithms, their design and implementation techniques, and a collection of successful applications.

Polynomial predictive filtering in control instrumentation: a review

This paper presents a study of the suitability for FPGA design of full custom based CORDIC implementations. Since all these methods are based on redundant arithmetic, the FPGA implementation of the required operators to perform the different CORDIC methods has been evaluated. Efficient mappings on FPGA have been performed leading to the fastest implementations. It is concluded that the redundant arithmetic operators require a 4 to 5 times larger area than the conventional architecture and the speed advantages of the full custom design has been lost. That is due to the longer routing delays caused by the increase of the fan-out and the number of nets. Therefore, the redundant arithmetic based CORDIC methods are not suitable for FPGA implementation, and the conventional two's complement architecture leads to the best performance.

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Evaluation of CORDIC Algorithms for FPGA Design

This paper presents the design and implementation of a motor control IC for permanent magnet AC (PMAC) servo motors using the field programmable gate array (FPGA). This paper develops a hardware architecture for the digital control of PMAC servo motors. The proposed control structure has also been realized using FPGAs from Xilinx Inc. All the control functions, including the PWM waveform generation, current control, vector control, velocity control, and position control have been realized using FPGA based programmable logic gates. The constructed PMAC control IC includes 25000 logic gates and is realized using 8-bit integer arithmetic. Experimental results are given to verify the implemented PMAC control IC.

Design and implementation of all FPGA-based motor control IC for permanent magnet AC servo motors

Predictive synchronization and restoration of corrupted velocity samples

Field Programmable Gate Arrays (FPGAs) offer a cost-effective and flexible technology for DSP ASIC prototype development. In this article, the fast ASIC prototyping concept based on the use of multiple FPGAs is reviewed in different engineering applications. The design experiences of the proposed approach, applied to four different DSP ASIC design projects are presented. The design experiences concerning the selection of the design methodology, application architectures and prototyping technologies are analyzed with respect to efficient system integration and ASIC migration from the FPGA prototype onto first-time functional silicon. Novel prototyping techniques based on using configurable hardware modellers concerning the same objective are studied. Some future goals are outlined to develop an integrated, multipurpose DSP ASIC prototyping environment.

DSP system integration and prototyping with FPGAS

Discrete-time computational models of squirrel-cage AC motors are derived and analyzed for the purpose of advanced motor control. The starting point is a continuous-time model defined by a pair of simultaneous complex-coefficient differential equations. Discrete-time models are derived using both the bilinear transformation and the forward-difference approximation. The exact dependence between stability and the minimum sampling rate in the forward-difference approach is shown. The responses of the two discretized models are compared using real-world motor parameters. Using the forward difference method, a more compact implementation is obtained (although a higher sampling rate is required) as compared to the bilinear transformed model of equivalent performance and 2.7 times higher computational complexity. A 16/24-b DSP-ASIC coprocessor prototype implementing the AC motor model is introduced. >

A digital signal processing approach to real-time AC motor modeling

A digital motion control system is presented with primary applications in automatic elevator doors. Digital signal processing methods are used for generating exponential waveforms for the drive motor. The unit keeps track of the actual speed of motion and the corresponding door position. Thus the time consumed by door motion is minimized, and smooth acceleration and deceleration phases are achieved. The proposed algorithm results in an efficient bit-serial application specific IC (ASIC) implementation. >

An integrated digital motion control unit

Evaluates the utilization of the fast prototyping concept using the practical design experience gained in DSP ASIC integration on the basis of both schematic capture and VHDL based synthesis. The main emphasis of this work is in the high level problematics: the motivation of prototyping, the selection of prototyping technology, and the design methodology. >

J. Pasanen

Papers

Predictive synchronization and restoration of corrupted velocity samples

DSP system integration and prototyping with FPGAS

A digital signal processing approach to real-time AC motor modeling

An integrated digital motion control unit

DSP ASIC evaluation with fast prototyping