Petru Dobra

Rapid prototyping of control systems using embedded target for TI C2000 DSP

The paper presents a digital control application, in which a tuning method is proposed for DC motors, using DSP from Texas Instruments (TI). Experimental application for the DC motor illustrates the effectiveness and the simplicity of the proposed method for controller design. The control algorithm for the drive 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. The DC Motor is driven by pulse width modulated (PWM) signals generated by the DSP.

Robust PI control for servo DC motor

The paper reexamines the standard nested three loop controller structure for a permanent magnet DC motor in position servo applications. An analysis of a generic example demonstrates that the robust synthesis, via LMI optimization, offers noticeable improvements in performance especially in cases of relatively large model uncertainties. The proposed technique guarantees uniform exponential stability of the closed loop system, a desired rate of convergence, and H/sup /spl infin// norm bound.

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.

An improvement on empirical modelling of the batteries

Batteries are devices that convert chemical energy contained in its active materials into electric energy throughout electrochemical red-ox reactions. Theoretically, the energy provided by a battery depends only on its active substances. Practically, just a part of a batterys capacity can be used, due to the nonreactive substances that add up to the process and which influence the magnitude of the charge-transfer reaction, diffusion rates and energy losses. In this paper five methods for modeling the batteries were presented, and one improved empirical model was implemented. The empirical model was built using Mathcad and was validated through the comparison of the experimental obtained characteristics with the ones given by the producer.

Fault Detection and Diagnosis for Continuous Time Process

Abstract 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’s operation 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 process parameter. 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 process. Continuous time parameters can be related easily to the physical characterizations of process. The parameter is to directly estimate by well-known prediction error method of identification for dynamic systems. The failure detection it is based on process coefficient’s changes and statistical decision methods. Unlike usual papers, the failure can be detected whether others process parameters are not constant.

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.

Digital Control of a Two Phase Motor

In this paper a two-phase motor control with an AtMega8 microcontroller is presented. The energy efficiency of motor-driven products is increased by adding variable speed control using a microcontroller. In this way, the motor can be operated in a wide range of speed and the implemented power saving procedures increases energy efficiency of motor-driven product. The motor is controlled by two Sinus Weighted PWM signals, displaced 90 degree in phase, with variable frequency and amplitude. To achieve greater efficiency the motor is started at low speed and accelerated to the operational speed. Also, at the first start the real power is measured for each operating speed, allowing in this way to find out the most energy efficient speed. The motor will be operated at this speed as much as possible.

The opportunity of energy arbitrage by using predictive control in a solar passive house

Energy consumption in buildings is the most significant component of the overall energy consumption in western countries, but also worldwide. There are some important initiatives which aim at developing new ways of decreasing the consumption of energy related to buildings. New types of buildings, like the passive ones are part of these initiatives. Local energy production and consumption is the most effective way of harnessing the maximum benefit from energy, but because of the limited possibility to generate clean energy locally, the management of local energy production should be optimized up to the maximum. Smart control systems and high energy performance buildings combined with predictive control strategies will not only reduce the overall cost related to energy, but will also help monetizing the local production in the future.

Efficient implementation of sliding mode control for BLDC PM motor using TMS320F28335 microcontroller

The sliding mode control (SMC) approach is reconsidered for the three phase brushless direct current motor with permanent magnets (BLDC PM). For mathematically matching the SMC to BLDC PM, brief discussion is also made on the mathematical modelling of the BLDC PM motor. The speed control loop for electric drive with BLDC PM is tested especially for load torque variation that will be assumed as additive uncertainty. The loop control implementation uses the TMS320F28335 microcontroller with special processing facilities for electric drive signals. The final target is to validate a fast procedure of setting up the speed/position control loop with a simple starting SMC algorithm. Test results using different valued parameters of the proposed SMC support the rapid prototyping procedure.