Milan Curkovic

FPGA-Based Predictive Sliding Mode Controller of a Three-Phase Inverter

This paper proposed a novel predictive variable-structure-switching-based current controller for a three-phase load driven by a power inverter. The design specifications are robustness to load electrical parameters, fast dynamic response, reduced switching frequency, and simple hardware implementation. In order to meet previous specifications, a sliding mode controller has been developed, which is designed as finite-state automata, and implemented with a field-programmable gate array (FPGA) device. The switching strategy implemented within the state transition diagram provides for a minimum number of switches by the three-phase inverter that is confirmed through simulation and experimental results. Its regulation using the proposed control law provides good transient response by the brushless ac motor control. However, this does not limit the wider applicability of the proposed controller that is suitable for different types of ac loads (rectifier and inverter) and ac motors (induction, synchronous, and reluctance). A new logical FPGA torque and speed controller is developed, analyzed, and experimentally verified.

Identifying dynamic model parameters of a BLDC motor

Abstract An off-line identification method founded on the least-squares approximation technique and a closed-loop disturbance observer is applied for identifying the parameters of a BLDC motor model. No special configuration of the motor is required besides the availability of experimental data for back-EMF, phase currents, rotor position, and rotor speed. This method is used to identify the back-EMF harmonics and mechanical parameters, where the mechanical parameters refer to cogging-torque, viscous friction coefficient, and Coulomb friction coefficient. The proposed identification method is theoretically investigated, and the method’s effectiveness is proved by experimental results performed on a low-power BLDC motor.

DSP based rapid control prototyping systems for engineering education and research

This paper presents custom made, DSP-based rapid control prototyping (RCP) systems that are suitable for control engineering education and research. Presented RCP systems provide an easy transition from the model-based control system design in MATLAB/Simulink to embedded DSP-based target implementation. In addition to rapid binary code generation, Lab VIEW data visualization and parameter tuning solution is presented. The paper also includes an example of cascade DC motor control

A Switching Control Strategy for the Reduction of Torque Ripple for PMSM

This paper proposes the field-programmable gate array (FPGA) implementation of a variable structure system predictive sequential switching control strategy, as applied to a permanent magnet synchronous machine. In the case of ac motor drives, in contrast to conventional vector control where the inverter is not taken into consideration by the controller, the proposed control integrates the inverter model and the inverter states. It allows obtaining faster torque dynamics than vector control algorithms. The main design specifications are a reduced switching frequency and simple hardware implementation. A predictive sliding mode controller has been developed, designed as finite-state machine, and implemented with a FPGA. This new logic FPGA torque and speed controller has been developed, analyzed, and experimentally verified.

An Event-Driven Approach to the Current Control of a BLDC Motor Using FPGA

A mechatronic system consists of a mechanical system and electric actuators. The presented event-driven control of a mechatronic system has been implemented on a field-programmable gate array (FPGA) platform. The supervisor provides robust, safe, and transparent control, where the finite-state machine (FSM) defines all the possible directions for implementation. In order to make the supervisor more transparent, the FSM has been divided into three main parts, each signified by a main color (green, yellow, and red - semaphores). These colors indicate the condition of the system. The supervisor has been upgraded with a graphical user interface with indicators that directly show the state of the FSM. The interface includes additional logical I/O signals, in order to make the system more useful. The supervisor is executed parallel to the basic motor control on the FPGA. This paper introduces a robust current controller of a brushless ac (BLAC) motor, upgraded with a proportional-integral velocity controller. The application of the proposed event-condition-action-based method is illustrated using the example of the FSM motion control of a BLAC motor with integrated I/O signals.

Efficient Stepper Motor Torque Ripple Minimization Based on FPGA Hardware Implementation

There are two main reasons for torque ripple effect when stepping motor with permanent magnet is considered. First is the non-sinusoidal flux distribution and the second is so-called cogging torque. This paper presents theoretical torque ripple minimization procedure and extensive description of its implementation on an FPGA device

Nonlinear Torque Control of BLAC Motor

Abstract This study presents the implementation of a hybrid control strategy applied to a brushless AC (BLAC) motor drive. Hybrid control is a general approach for control of a switching-based Hybrid Systems (HS). This class of HS includes a continuous process controlled by a discrete controller with a finite number of states. The overall stability of the system is shown using Lyapunov technique. The Lyapunov functions used contain a term penalizing incremental energy of control error, torque and stator current, enhancing the stability. The closed-loop system with the proposed control low provides good transient response and good regulation the BLAC motor control. A new logical FPGA torque controller based on Lyapunov theory are developed, analyzed and experimentally verified.

FPGA Based BLDC Motor Current Control with Spectral Analysis

This article presents two different approaches of brushless dc motor torque control, PI and discontinuous sliding mode regulator. Algorithms were implemented on NI 7831R board consisted of Xilinx FPGA device and peripheral (A/D and D/A converters). Frequency analysis of motor current has been made to demonstrate the influence of using specific control algorithm on the motor power signal frequency content.

Robust speed sensorless control of PMSM

This paper presents a speed sensorless non-salient permanent magnet synchronous motor (PMSM) sliding mode control algorithm. The key idea is to integrate the benefits of the variable structure system control design and the event-driven sequential control structures to raise the system performance and control efficiency. The operation at low speed is improved by reducing the disturbance impact. The estimation angle error at zero speed is limited by injecting the DC current that compensates the unknown load torque and enables operation at zero speed. The VSS speed sensorless control of PMSM is implemented on a DSP/FPGA system, and verified experimentally.

Event-driven approach to control mechatronic system with FPGA

A mechatronic system consists of a mechanical system and electric actuators. The event-driven control of a mechatronic system was implemented on a field-programmable gate-array (FPGA) platform. The supervisor provides robust, safe, and transparent control, where the FSM defines all the possible directions for implementation. In order make supervisor more transparent, the FSM was divided into three main parts, with three main colours (green, yellow and red - semaphore). These colours indicate the condition of the system. The supervisor was upgraded with a Graphic user interface (GUI) with indicators that directly show the state of the FSM. The GUI includes additional logical I/O signals, in order to make system more useful. The supervisor is executed parallel with the basic motor control on the FPGA. This paper presents the robust current controller of the brushless ac (BLAC) motor, upgraded with a classical PI velocity controller. The application of the proposed ECA-based method is illustrated using the example of the FSM motion control of a BLAC motor with integrated I/O signals.