Application of averaged instantaneous power spectrum for diagnostics of machinery operating under non-stationary operational conditions

Small robots can be beneficial to important applications such as civilian search and rescue and military surveillance, but their limited resources constrain their functionality and performance. To address this, a reconfigurable technique based on field-programmable gate arrays (FPGAs) may be applied, which has the potential for greater functionality and higher performance, but with smaller volume and lower power dissipation. This project investigates an FPGA-based PID motion control system for small, self-adaptive systems. For one channel control, parallel and serial architectures for the PID control algorithm are designed and implemented. Based on these one-channel designs, four architectures for multiple-channel control are proposed and two channel-level serial (CLS) architectures are designed and implemented. Functional correctness of all the designs was verified in motor control experiments, and area, speed, and power consumption were analyzed. The tradeoffs between the different designs are discussed in terms of area, power consumption, and execution time with respect to number of channels, sampling rate, and control clock frequency. The data gathered in this paper will be leveraged in future work to dynamically adapt the robot at run time

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FPGA implementation of closed-loop control system for small-scale robot

Summary

Deflection curve can be used to detect and localize damage in civil engineering structures. In this paper, a vision-based method applied for in-plane displacement field measurement of cantilever beams is presented. The deflection curve of the analyzed structure is computed by means of the digital image correlation. Damage is introduced into the structure. Resulting deflection curves are used as an input to the novel damage detection algorithms: line segments method and voting method. The algorithms are then compared with the second derivative method and assessed through the probability of detection procedure. Copyright © 2015 John Wiley & Sons, Ltd.

Vision‐based algorithms for damage detection and localization in structural health monitoring

Wavelet-based Frequency Response Function for time-variant systems—An exploratory study

This paper deals with non-singular tool path generation of a 5-axis hybrid robot named TriMule, which is designed for large part machining in situ. It is observed that at a singularity pose sudden changes occur in rotation of the C-axis and lengths of three telescopic legs. It is found that when the tool axis rotates about the axis normal to the plane expanded by the tool axis and the singular axis, the singular axis itself is forced to rotate simultaneously about the same axis in the opposite direction. This exploration enables the minimum rotation angle of the tool axis to be determined accurately for avoiding singularity and reducing machined surface errors caused by tool axis modification, leading to the development of an algorithm for non-singular tool path generation by modifying a partial set of the control points of B-splines. Both simulation and experiment on a prototype machine are carried out to verify the effectiveness of this approach.

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Inverse kinematics of a 5-axis hybrid robot with non-singular tool path generation

CNC system of the 5-axis hybrid robot for milling

In the paper, a procedure of semi-automatic hardware implementation of control algorithms is presented. Important role in this procedure plays generator of ASIC/FPGA synthesisable code from Simulink model. Virtual prototyping of entire mechatronic system is possible, including bit and cycle-accurate simulation of hardware-implemented controller in Simulink. As a case study, nonlinear PID control of prismatic robot link with friction is described.

Semi-automatic implementation of control algorithms in ASIC/FPGA

In this paper the recursive method for modal parameters estimation is formulated and verified. Formulated algorithms are implemented in the FPGA electronic chip. As a result, the modal parameters and confidence bounds for the modal parameters are obtained in real time. The algorithms and their implementations are tested on laboratory test rig data and applied to – flight modal analysis of an airframe structure.

/pdf/real-time-estimation-of-modal-parameters-and-their-quality-12phfdujif.pdf

Real Time Estimation of Modal Parameters and Their Quality Assessment

Trajectory tracking controller of the hybrid robot for milling

The paper presents the process of development of parallel manipulators for milling, and justifies why mechatronic approach can lead to successes. The resulting construction is a novel, versatile 3-RRPRR (revolute-revolute-prismatic-revolute-revolute joints), fully-parallel manipulator with three translational degrees of freedom, characterizing in comparatively high payload capacity, large workspace and high attainable accelerations. The construction of the manipulator is shown, with analysis of its kinematics and dynamics. An initial controller for identification is proposed, simulated and experimentally investigated. Finally, the conclusions are presented

Maciej Petko

Papers

CNC system of the 5-axis hybrid robot for milling

Semi-automatic implementation of control algorithms in ASIC/FPGA

Real Time Estimation of Modal Parameters and Their Quality Assessment

Trajectory tracking controller of the hybrid robot for milling

Mechatronic design of a parallel manipulator for milling