Mirela Trusca

Low-cost embedded solution for PID controllers of DC motors

Proportional Integral Derivative (PID) control is the most common control algorithm used in industry today. The popularity of PID controllers can be attributed to their effectiveness in a wide range of operating conditions, their functional simplicity and how easily engineers can implement them using current computer technology. This article discusses PID control and practical implementations and provides a brief overview on how to tuning parameters of PID controllers.

Adaptive system identification and control using DSP for automotive power generation

The paper presents an adaptive system identification and control application using a digital signal processor (DSP) from Texas Instruments (TI). The system to be modelled is an automotive alternator. Experimental application illustrates the effectiveness and the simplicity of the proposed method. The application runs on a TMS320F2812 DSP. Once the desired functionality has been captured and simulated, using MATLAB/Simulink/Embedded Target for TI C2000 DSP environment can be generated code for the DSP. All task assignments to processor are automatically made by the software. Once the coefficients of the digital filter are calculated the mathematical model of the unknown system is determined. A control algorithm is implemented in order to control the output voltage of the alternator.

Model based approach in fault detection and diagnosis for DC motor

Recent advances in microelectronic circuit have enabled the application of process diagnostics to a variety of systems to improve performances and the reliability. Failure detection and isolation strategies monitor a system for degradations and if detected, classify the failure source. One of the most important methods for failure detection and diagnosis is the analysis of the variations of the estimated parameter of DC Motor. In this paper is presented a structure of a method for failure detection and diagnosis based on continuous time parameter estimation of a mathematical model of the DC Motor. Continuous time parameters can be related easily to the physical characterizations of DC Motor. The parameter is directly estimated by well-known prediction error method of identification for dynamic systems. The failure detection it is based on changing the process coefficient and statistical decision methods. Unlike usual papers, the failure can be detected whether others process parameters are not constant.

Wireless low cost embedded solution for electrical motors control

The use of remote control is more and more popular as the wireless devices evolve and are easier to use. This paper describes a simple low power wireless protocol from Texas Instruments called SimpliciTI and presents a remote embedded control application. A DC motor with brushes is monitored over a wireless communication network, the speed reference is sent from a user interface running on a PC and the same interface displays the actual speed and current of the motor. For the implementation of the control algorithm and for wireless communication the EZ430-RF2500 development tool is used.

Spectrum analyzer instrument based on OMAP3530

OMAP3530 is a Multiprocessor System-on-Chip (MPSoC) device which integrates ARM Cortex-A8, C64x+, Graphics Accelerator and various peripherals, its designed to meet mobile multimedia applications so it is a good solution for a spectrum analyzer implementation. In this paper is presented a spectrum analyzer instrument implementation based on OMAP3530 architecture, using FFT algorithm. The FFT algorithm is implemented on DSP and the user interface is implemented on ARM and Linux OS. DSP/BIOS Link, library for the inter-processor communication across the ARM-DSP boundary is used This instrument could be a good solution for vibration analyses using an accelerator sensor, sound or any other periodical input signal. To test this spectrum analyzer instrument during the application development a sound wave was used as input signal. On the ARM side a Linux OS is used, which ensure a proper solution for user interfaces (S-Video, DVI, LCD, touch screen) and interconnections (UART, USB, Ethernet).

Adaptive control approach in case of a rigid link robot system

The case of an adaptive controller is developed for a robot system actuated by brushed direct current motors in the presence of external disturbances and parametric uncertainties. The control scheme requires the measurements of link position and armature current for feedback. The elaborated adaptive controller results in a closed-loop system locally stable while the all states and signals are bounded and the tracking error can be obtained as small as possible. The advantage of the presented algorithm consists in the number of parameter estimates equal to the number of unknown parameters throughout the entire mechanical system. In consequence, it is eliminated the overparametrization induced by employing the integrator backstepping technique in control of electrically driven robots. Finally, the performance of the proposed approach is illustrated in simulation examples.

Robust stability of time-varying nonlinear systems using popov criterion

Abstract This paper establishes sufficient conditions for absolute stability of time-varying control systems. The proposed conditions extend the classical Popov criterion to time-varying memoryless nonlinearities, using previous results of Kharitonov. They are expressed in terms of Linear Matrix Inequalitie ( LMI ). The results ensure in general local stability, however, the stability is global for linear time-varying systems. An example is presented to show the efficacy of these extensions within the MATLAB environment.

Robust controller for a brushless DC motor based on the gain and phase margin

In comparison to classical DC motors, brushless DC motors are very reliable. Nevertheless, they can also fail, caused by overheating or mechanical wear. This paper proposes a design of robust controller (via H/sup /spl infin// technique) for a brushless DC motor with requirement for gain (m/sub k/) and phase (/spl gamma//sub k/) margin. A simple way to include the amplitude and phase margins in a design is to include a dynamic uncertainty block in configuration. This block contains one parameter (k/sub m/), that is a measure of the stability margins to be imposed on the closed loop system. The overall gain from input to output depends on the uncertainties (/spl Delta/) and the parameter (k/sub m/), and it is placed where the margin is needed. The advantages of this modeling of unstructured uncertainties are illustrated on a brushless DC motor.

Model based fault detection for electrical drives with BLDC motor

Continuous improvements in microelectronic circuitry make possible the implementation of process diagnostics to a variety of systems in order to increase performances and reliability. The monitoring stage in the area of failure detection and isolation aims to classify and arrange the failure sources. In case of BLDC machines, one of the most important methods for failure detection and diagnosis starts with the analysis of the variations of the machine estimated parameters. The paper focuses on the implementation details of failure detection and diagnosis based on continuous time parameters estimation of BLDC motor mathematical model. Continuous time parameters are directly related to the physical characterizations of BLDC Motor. The parameters are estimated by the well-known prediction error methods devised for dynamic system identification. By changing the process coefficients and by applying statistical decision methods, failure detection occurs. The case of frequency domain identification in fail detection is also covered on a real CNC machine. Discrete Fourier Transform (DFT) with the particular case of Goertzel algorithms is implemented for fault detection purposes. Unlike existing work and results in the fault detection area, the failure can be detected among time-varying process parameters.

Digital Motor Control Library

The paper present Rapid Control Prototyping (RCP) libraries for Matlab/Simulink, which are used to generate real-time C code for the Renesas M32C87 microcontroller. The libraries are integrated in the toolbox Target for Renesas M32C87. Simulink blocks are implemented for drivers and algorithms specific for the Renesas M32C87 microcontroller. The toolbox contains five libraries: I/O drivers, Digital Motor Control (DMC), Controller Area Network (CAN) and Serial Communication Interface (SCI). In this paper the DCM library is described in detail. A positioning application for a Computer Numerical Controlled (CNC) machine is implemented using the Renesas M32C87 microcontroller.