Control Processor Research Articles

Design of GTAW Wire Feeder Control System Based on Nios II

Based on Nios II embedded processor control module, a digital control system was designed for wire feeding control of gas tungsten arc welding(GTAW). In the control system FPGA wave module is used to control the movement of the DC servo motor, and the digital control of pulsed wire feeder for GTAW was achieved. One and the same control module with Nios II embedded processor is used to control the wire feeder and the welding power source. Thus, the current parameter of pulsed welding arc can be obtained and used directly for controlling the speed of wire feeding. At last, the experiment results are provided to verify the validity.

Research on Ontology Knowledge Based System of Meteorological and Hydrological Support

According to knowledge sharing&reusing problem and system extensibility&portability problem in meteorological and hydrological support, the knowledge concepts, attributes, instances, hierarchy and relationships were clarified; the ontological knowledge base was established by OWL ontology language and SWRL rule language. With the help of Racer, Protégé, Jess, and class positioning algorithm, class testing algorithm, rule testing algorithm, the meteorological and hydrological support prototype system was implemented by Eclipse, ProtegeInEclipse plug-in and Jena. The system includes the server, the client and the processing controller. It provides artificial intelligence techniques means for knowledge maintenance and usage in meteorological and hydrological field.

Indoor autonomous flight of ornithopter using motion capture system

PurposeThe purpose of this paper is to perform an indoor autonomous flight of ornithopter using a novel motion capture system.Design/methodology/approachThe ornithopter platform has no on‐board sensors and processors for state estimation or feedback control. Instead, passive markers on the ornithopter body reflect IR light of the multiple strobing CCD cameras, and the position data of the markers are streamed to the ground station in almost real time. Control inputs such as wingbeat frequency and rudder angle are generated by the proportional feedback controllers which are implemented in the ground station and transmitted to the ornithopter. Due to the complexity and nonlinearity of aerodynamics and flexible multibody dynamics, the flight dynamics of ornithopter are difficult to realize in the closed form of state‐space system equations. A controller for stabilizing the flight state variables of ornithopter is not necessary to be implemented by means of flapping counter‐forces and torques which make ornithopter have inherent flight stability. The gains of controllers for following circular trajectories are obtained by a trial‐and‐error approach rather than a model‐based design.FindingsThe autonomous ornithopter successfully circulates the pre‐described radius with the constant altitude and the result shows that control strategies proposed in this study are sufficient to implement the autonomy of ornithopter flight.Originality/valueThe autonomous flight of ornithopter is firstly conducted in a confined indoor environment by using the motion capture system and the control performance is evaluated in terms of position errors.

Novel Wavelet-Fuzzy Based Indirect Field Oriented Control of Induction Motor Drives

This paper presents a wavelet-fuzzy based controller for indirect field oriented control of three-phase induction motor drives. The discrete wavelet transform is used to decompose the error between the actual speed and the command speed of the induction motor drive into different frequency components. The transformed error coefficients along with the scaling gains are used for generating the control component of the motor. Self-tuning fuzzy logic is used for online tuning of the scaling gains of the controller. The proposed controller has the ability to meet the speed tracking requirements in the closed loop system. The complete indirect field oriented control scheme incorporating the proposed wavelet-fuzzy based controller is investigated theoretically and simulated under various dynamic operating conditions. The simulation results are compared with a conventional proportional integral controller and a fuzzy based controller. The speed control scheme incorporating the proposed controller is implemented in real time using a digital processor control board. Simulation and experimental results validate the effectiveness of the proposed controller.

The Development of RFID Data Management System Based on Embedded System

Embedded system in general is formed by the embedded computer system and implementing device. Embedded system is a control program stored in ROM embedded processor control board. The basic function of Radio Frequency Identification (RFID) is to realize the precise data acquisition. RFID reader via the antenna and the RFID tag for wireless communication can be achieved on the label identification code and a memory data read or write operation. The paper presents the development of RFID data management system based on embedded system. Experimental results show that the proposed algorithm has high efficiency.

Interdependent Multi-Layer Networks: Modeling and Survivability Analysis with Applications to Space-Based Networks

This article develops a novel approach and algorithmic tools for the modeling and survivability analysis of networks with heterogeneous nodes, and examines their application to space-based networks. Space-based networks (SBNs) allow the sharing of spacecraft on-orbit resources, such as data storage, processing, and downlink. Each spacecraft in the network can have different subsystem composition and functionality, thus resulting in node heterogeneity. Most traditional survivability analyses of networks assume node homogeneity and as a result, are not suited for the analysis of SBNs. This work proposes that heterogeneous networks can be modeled as interdependent multi-layer networks, which enables their survivability analysis. The multi-layer aspect captures the breakdown of the network according to common functionalities across the different nodes, and it allows the emergence of homogeneous sub-networks, while the interdependency aspect constrains the network to capture the physical characteristics of each node. Definitions of primitives of failure propagation are devised. Formal characterization of interdependent multi-layer networks, as well as algorithmic tools for the analysis of failure propagation across the network are developed and illustrated with space applications. The SBN applications considered consist of several networked spacecraft that can tap into each other's Command and Data Handling subsystem, in case of failure of its own, including the Telemetry, Tracking and Command, the Control Processor, and the Data Handling sub-subsystems. Various design insights are derived and discussed, and the capability to perform trade-space analysis with the proposed approach for various network characteristics is indicated. The select results here shown quantify the incremental survivability gains (with respect to a particular class of threats) of the SBN over the traditional monolith spacecraft. Failure of the connectivity between nodes is also examined, and the results highlight the importance of the reliability of the wireless links between spacecraft (nodes) to enable any survivability improvements for space-based networks.

Operation of inverter‐assisted wind‐driven slip‐ring induction generator for stand‐alone power supplies

The operation of wind-driven single inverter-battery-assisted slip-ring induction generator (SRIG) for stand-alone power supplies has been proposed. For effective utilisation of wind energy, the proposed system will function as doubly fed induction generator (DFIG) or shorted stator induction generator (SSIG) depending upon the ac load requirement and available wind power, operating in four different modes. A method has been developed for the performance predetermination of such system. A supervisory control algorithm has been devised and implemented using TMS320LF2407A real time digital signal processor for the closed-loop control of the proposed system. In this control algorithm, reliable and unambiguous feedback signals such as stator voltage, stator current and user command are used for decision making and for closed-loop operation. The entire closed-loop system with supervisory control algorithm has been tested in the laboratory with a 3.7 kW SRIG. The successful working of the proposed system with smooth changeover between the operating modes has been demonstrated with extensive experimental and simulation results. The advantage of the proposed wind energy system has also been brought out in comparison with classical back to back converter DFIG system for stand-alone power supplies.

Microarchitecture of a Coarse-Grain Out-of-Order Superscalar Processor

We explore the design, implementation, and evaluation of a coarse-grain superscalar processor in the context of the microarchitecture of the Control Processor (CP) of the Multilevel Computing Architecture (MLCA), a novel architecture targeted for multimedia multicore systems. The MLCA augments a traditional multicore architecture (called the lower level) with a CP (called the top-level), which automatically extracts parallelism among coarse-grain units of computation (tasks), synchronizes these tasks and schedules them for execution on processors. It does so in a fashion similar to how instruction-level parallelism is extracted by superscalar processors, i.e., using register renaming, Out-of-Order Execution (OoOE) and scheduling. The coarse-grain nature of tasks imposes challenging constraints on the direct use of these techniques, but also offers opportunities for simpler designs. We analyze the impact of these constraints and opportunities and present novel microarchitectural mechanisms for coarse-grain superscalar execution, including register renaming, task queue, dynamic out-of-order scheduling and task-issue. We design an MLCA system around our CP microarchitecture and implement it on an FPGA. We evaluate the system using multimedia applications and show good scalability for eight processors, limited by the memory bandwidth of the FPGA platform. Furthermore, we show that the CP introduces little overhead in terms of resource usage. Finally, we show scalability beyond eight processors using cycle-accurate RTL-level simulation with an idealized memory subsystem. We demonstrate that the CP poses no performance bottlenecks and is scalable up to 32 processors.

Engine performance during tractor operational period

It was found that for monitoring operating performance of the tractors it is necessary to have tools and methods that, by using data provided by the manufacturer and controlled during tractor’s operational time, would allow to directly determine fuel consumption, exhaust emissions, engine load modes and other indicators. Such problems are dealt with in this article. Possibilities for using data accumulated in database of tractors’ engine control processors to explore engine load, fuel consumption and exhaust emissions are analyzed.This paper presents the results of engine load, fuel consumption and exhaust emissions’ research for tractor models Massey Ferguson MF 6499 with different operational time records within their operational period. The research results show how much time during the operational period, averagely, tractor engines worked by producing the torque 30%, 30–50% and >50% and the potential maximum torque in that mode. It is also presented how long engines operated at each load at slow speed (up to 1100rpm), medium speed (from 1100 to 1900rpm) and high speed (more than 1900rpm). The paper presents average fuel consumption and CO, CO2 and NOx emissions by the engines for every of these operation modes during operational period of the tractors.

SEU Fault-Injection in VHDL-Based Processors: A Case Study

Evaluating the sensibility of a given circuit with respect to soft errors became a main issue especially if it is intended to operate in space or at high altitudes. A hardware/software (HW/SW) approach to study the effects of soft errors by fault injection in the VHDL model of a CPU (Control Processor Unit) is presented and illustrated by results obtained for a LEON3 processor. The LEON3 is set to execute two benchmark algorithms. The first one is a typical 3x3 matrix multiplication, whereas the second one is a self-converging algorithm which is intended to provide correct results even if a failure occurs in the middle of the execution. The results of fault-injection campaigns targeting the register file unit of the processor are compared to those issued from a state-of-the-art method, the C.E.U. (Code Emulated Upset). One of the main advantages of the proposed method is the larger targeted Single Event Upset (SEU) sensitive area leading to improved error rate predictions.

Embedded Machine Vision System Design Based on Davinci DM355

Most existing machine vision processing system is 8-bit or 16-bit processor control system, complex algorithms and multi-tasking of the vision system have been severely constrained. DaVinci DM355 integrated ARM926 RISC processor core and specialized image processor is a programmable DMSoC development platform with digital multimedia codecs, high integration, low-power consumption. The machine vision system based on DaVinci DM355 development goal is to establish a low-power hardware development board based on the DaVinci DM355, transplant Linux operating system based on the hardware board and develop corresponding driver.This will provide the basis for the realization of complex algorithm and multitasking system for machine vision system.

Algorithm development of an intelligent traffic light control system.

This study presents an implementation of an intelligent traffic light control system for a crossroads based on combination of image processing and fuzzy controller. After certain seconds of red light, traffic densities are estimated from captured images. Based on this estimated result, a fuzzy controller determines the length of the next green light period in order to generate longer period for higher density road, vice versa. A software was developed to evaluate the suggestion algorithm, and to compare it with traditional timer-based traffic light system. Simulation results indicate that the road with higher traffic flow has a longer green light period, and vice versa. When the traffic’s densities of 2 roads are 5 times different, the vehicle red-light waiting times of the suggested system are reduced from 15 to 20 times better than the traditional system.

An improved Direct Adaptive Fuzzy controller for an uncertain DC Motor Speed Control System

In this paper, we present an improved Direct Adaptive Fuzzy (IDAF) controller applied to general control DC motor speed system. In particular, an IDAF algorithm is designed to control an uncertain DC motor speed to track a given reference signal. In fact, the quality of the control system depends significantly on the amount of fuzzy rules-fuzzy sets and the updating coefficient of the adaptive rule. This can be observed clearly by the system error when the reference input is constant and out of a particular range or in the case of it varies with nonzero acceleration. So, in order to enhance quality of the system, increasing the amount of fuzzy sets and adjusting appropriately the updating coefficient of controller based on value of state error vector are needed. In addition, the proposed IDAF algorithm can control the DC motor speed under unstable supply voltages and varying loads. The control system is implemented on a dsPIC33FJ256MC710A 16-bit DSC (Digital Signal Processing Controller) board. Experimental results demonstrate the effectiveness of the proposed method. DOI: http://dx.doi.org/10.11591/telkomnika.v11i2.1861 Full Text: PDF

221 短距離走における実レース計測のためのセンサシステムの開発と測定(センシング技術ほか)

The purpose of this study is to make the sensor system for capturing the movement of sprint running. The sensor system was constructed by the 3-dimentional acceleration sensor, the 3-dimentional gyro sensor, control processor and the operation device. Moreover, this sensors system has the software having the algorithm for dynamic calculation, and it can process the dynamic data on real time. In this study, we did an experiment to attempt the sensor system by capturing the running movement. As a result, the dynamic data of correct tendency was obtained. Furthermore, these data had represented parameters relating the running movement.

Hybrid phase shifted carrier modulation fed five-phase multilevel inverter for multiphase induction motor drive

This paper proposes an energy efficient modulation scheme suitable for multilevel inverter fed five-phase induction motor. Five-phase multilevel inverter provides good quality five-phase variable voltage and variable frequency supply to five-phase induction motor, which ensure reduced torque ripple and improved drive efficiency. This modulation inherits the features of fundamental frequency modulation and phase shifted carrier modulation in power conversion and resolves the contradiction between high frequency and accuracy in a digital control scheme. Base modulator and hybrid formulation control algorithms are realised with TMS320F2407 DSP processor and Xilinx XC95108 CPLD controllers. The performance studies with induction motor are evaluated in terms of power loss, weighted total harmonic distortion and torque ripple. Selected simulation and experiment results are reported to verify and validate the effectiveness of the proposed technique.

Robust Speed Control of an Induction Motor Drive using Wavelet-fuzzy based Self-tuning Multiresolution Controller

This paper presents a hybrid wavelet-fuzzy based multiresolution (MR) controller for robust speed control of induction motor. The discrete wavelet transform (DWT) is used to decompose the error between the actual speed and command speed of the induction motor drive in to different frequency components. A self-tuning fuzzy logic is used for online tuning of the controller parameters. The proposed controller has the ability of meeting the speed tracking requirements in the closed loop system. The complete indirect field oriented control scheme incorporating the proposed wavelet-fuzzy based MR controller is investigated theoretically and simulated under various dynamic operating conditions. Simulation results are compared with that of conventional PI controller and fuzzy based PI controller. The speed control scheme incorporating the proposed controller is implemented in real time using the digital processor (DSP) control board. Simulation and experimental results validates the effectiveness of the proposed controller over conventional controllers and proves to be more suitable for high performance applications.

Force Feedback Calculation of Thread in the Desktop-Based Thread Force Feedback System

The desktop-based thread force feedback system is divided into three logical parts. They are mechanical device, controller and data processing center. All kinds of interactive behaviors will be limited in the interactive space of the system. There exist two spaces of force feedback in the system. They are partial force space and entire force space. Operation vibrations will happen when the endpoints of threads enter from entire force space to partial force space. The vibrations will affect thread tension calculation. The quadratic program algorithm of thread tension can decrease vibrations and increase stability of thread force feedback when the tolerance coefficient is joined in the equations. It is a global optimization algorithm. The experiments have confirmed that threads tension changes will be smooth when the tolerance coefficient is not equal to zero.

A Hierarchical Self-Repairing Architecture for Fast Fault Recovery of Digital Systems Inspired From Paralogous Gene Regulatory Circuits

Self-repairing digital systems have received increasing attention as modern systems are getting more complex and fast. Currently available self-repairing architectures have, however, some limitations such as storage overhead required to prepare all possible rewiring strategies and temporal incorrectness caused by elongated repairing time. In this paper, we propose a novel self-repairing architecture for fast fault recovery with an efficient use of limited resources, which can be easily applied to real complex digital systems. The proposed architecture consists of three layers: a working layer, a control layer, and an interface layer. The working layer employs a hybrid scheme of using both redundant and empty cells with a newly devised self-test. This relieves the overhead of redundant cells required to be prepared in advance by considering every possible fault situation. In the control layer, an ordered assignment control is proposed. The order of working-priority of each processor that controls a normal cell in the working layer is predetermined. A faulty processor is detected by a majority decision among neighboring control processors and corrected by rearranging the order of working-priority. The interface layer connects an external PC for reprogramming. Through this fault recovery mechanism, the system can keep normal functioning under noisy environments. We implemented the proposed self-repairing architecture using an field-programmable gate array board with an application of a dot-matrix LED display and verified its robust operation. The proposed architecture can be widely used as a new platform for self-repairing systems.

Design of Data Acquisition System Based on DSP and Optical Fiber Bundle

This paper introduces the design of a DSP-based acquisition system with high parallelism of the beam. The system uses fiber arrays connected to spatial filters as the detection devices. A TMS320LF2407A DSP is adopted as the primary embedded processor, which connects Analog to Digital (A/D) converters via I/O ports. Simultaneously, the processor realizes the parallel processing of data storage, transmission and calculation. The design of the main processor control module, the signal processing module and its corresponding software, are discussed in detail.

Design, dynamic simulation and construction of a hybrid HTS SMES (high-temperature superconducting magnetic energy storage systems) for Chinese power grid

High-temperature superconducting magnetic energy storage systems (HTS SMES) are an emerging technology with fast response and large power capacities which can address the challenges of growing power systems and ensure a reliable power supply. China Electric Power Research Institute (CEPRI) has developed a kJ-range, 20 kW SMES using two state of art HTS conductors, BSCCO and YBCO tapes. This SMES system is used to compensate a power drop and a fluctuation in order to damp low frequency oscillations to increase stability of a power system. This paper presents an optimized design of the SMES system to achieve a maximum energy capacity. A voltage source converter using IGBTs is built and can be used to control the power flow between the SMES system and external circuits. A control system using a digital signal processor (DSP) and micro-programmed control unit (MCU) is constructed. SVPWM pulse modulation is used as a control strategy. The whole system was experimentally tested for compensation of power fluctuation within milliseconds in a dynamic power system simulation laboratory. The result validates the design and control circuit, and more importantly, the application capability of SMES systems in a power grid.