Ryszard Beniak

Influence of stator structure on electromechanical parameters of torus-type brushless DC motor

Five torus-type brushless dc motors, each with a different version of the stator core structure, are analyzed. The first one is a slotless stator core, and the four others have the space between the adjacent coils of stator winding filled with the material made either of iron powder composite or laminated iron. An analysis of the motor performance is based on a three-dimensional (3-D) field motor model as well as on the circuit model of the inverter plus the motor set supplied from the battery. The toothed stator core versions show a significant increase of the average torque and also an increase of torque ripple caused mainly by the rise of cogging torque. The analysis based on the simulation results is backed by measurements carried out on the prototype of slotless stator version of the motor.

Modeling and control-related analysis of the ground pressure exerted by wheels in a tri-wheel mobile robot.

The paper presents a method for modeling of the ground pressure exerted by the wheels of a tri-wheel mobile robot followed by a control algorithm that includes changes in the pressure. The simulation output is compared with the measured values of the ground pressure, demonstrating a very good modelling accuracy. Based on the modelled ground pressure characteristics, we successfully modify the equations of the well-known PWM regulator.

Comparing control algorithms of quadrocopters to implement their atypical maneuvers

This paper compares three different control methods of quadrocopters: linear-quadratic regulator, the method of inverse dynamics and full state feedback. The aim of this paper is to compare examined methods of control in respect of quadrocopters energy consumption and accuracy of obtained trajectories. We evaluate efficiency of these methods, based on an example of quadrocopters motion along an “eight shaped” trajectory, and recommend the best control method for regulator synthesis.

Correction of odometry errors in a tri-wheel mobile robot

This paper presents a simple algorithm for controlling robot trajectory that accounts for the torsion angle of a castor wheel. We identify the dynamics of the castor wheel as a plant of the second order inertia and then we successfully apply this information in the PWM (Pulse Width Modulation) regulator.

Mobile robot with non-slip castor wheel

In this paper we address a problem of a non-slip castor wheels impact on the control system of a tri-wheel mobile robot, which moves on a flat surface. We derive relations between the castor wheels torsion angle and drive velocities and show results of controllers simulation, with and without the impact of the castor wheel.

Stability analysis of a tri-wheel mobile robot

This paper presents a solution to the stability problem for a tri-wheel mobile robot with non-slip castor wheel. It is assumed that the robot is moving on a flat ground. The stability analysis is conducted for a nonholonomic robot model by means of the Lyapunovs direct method.

Determining control algorithms for voltage inverters basing on measurements

This paper describes ways to determine control algorithm in voltage inverters based on the obtained measurement waveforms. I consider two types of control algorithm, direct torque and flux control (DTFC) as well as pulse width modulation (PWM) scalar control. In the case of the DTFC control, I apply a concept of tracking control. In the case of the PWM scalar control, the value of command frequency and its modification are determined. Such a modification was necessary due to differences between measured and computed waveforms of the rotors angular velocity. Furthermore, the paper presents an effective method for eliminating the distortions which appear during the measurement operations. Having compared the measured and calculated waveforms, I conclude that the methodology which was assumed to determine whether the control algorithm in voltage inverters is correct and whether it ensures that the used control algorithm corresponds to the actual control algorithm to the highest possible extent.