Design and control of laser micromachining workstation

The production process of miniature devices and microsystems requires the utilization of non-conventional micromachining techniques. In the past few decades laser micromachining has became micro-manufacturing technique of choice for many industrial and research applications. This paper discusses the design of motion control system for a laser micromachining workstation with particulars about automatic focusing and control of work platform used in the workstation. The automatic focusing is solved in a sliding mode optimization framework and preview controller is used to control the motion platform. Experimental results of both motion control and actual laser micromachining are presented

Disturbance/uncertainty estimation and attenuation techniques in PMSM drives–a survey

This paper gives a comprehensive overview on disturbance/uncertainty estimation and attenuation (DUEA) techniques in permanent magnet synchronous motor (PMSM) drives. Various disturbances and uncertainties in PMSM and also other alternating current (AC) motor drives are first reviewed which shows they have different behaviors and appear in different control loops of the system. The existing DUEA and other relevant control methods in handling disturbances and uncertainties widely used in PMSM drives, and their latest developments are then discussed and summarized. It also provides in-depth analysis of the relationship between these advanced control methods in the context of PMSM systems. When dealing with uncertainties,it is shown that DUEA has a different but complementary mechanism to widely used robust control and adaptive control. The similarities and differences in disturbance attenuation of DUEA and other promising methods such as internal model control and output regulation theory have been analyzed in detail. The wide applications of these methods in different AC motor drives (in particular in PMSM drives) are categorized and summarized. Finally the paper ends with the discussion on future directions in this area

New Approaches in Automation and Robotics

The book New Approaches in Automation and Robotics offers in 22 chapters a collection of recent developments in automation, robotics as well as control theory. It is dedicated to researchers in science and industry, students, and practicing engineers, who wish to update and enhance their knowledge on modern methods and innovative applications. The authors and editor of this book wish to motivate people, especially under-graduate students, to get involved with the interesting field of robotics and mechatronics. We hope that the ideas and concepts presented in this book are useful for your own work and could contribute to problem solving in similar applications as well. It is clear, however, that the wide area of automation and robotics can only be highlighted at several spots but not completely covered by a single book

Robotic contour tracking with force control and an operational space disturbance observer

Robots in the industry are used for operations that are particularly dangerous or challenging to complete with high efficiency and precision for humans. These robots require extensive programming to achieve high level tasks and reprogramming to repeat the task in different environmental conditions. Introducing some level of autonomy for the robots is desired to decrease the burden on the programmer by enabling the robot to adapt to environmental changes and accomplish the required tasks with minimal human interaction. Contour tracking is a task that can be completed autonomously by a robot and assist in the completion of several industrial operations in the process such as grinding, deburring, polishing and shape recovery. Hybrid control is a popular method for achieving contour tracking. This thesis presents a hybrid controller that employs feedforward and integral force actions in the contact normal direction; and dynamics based proportional velocity control with disturbance estimation in the tangent direction. The effectiveness of the presented method has been validated and its superiority compared to conventional PI velocity control is proven experimentally. A simple and reliable method for contact estimation is also presented

Accuracy Enhancement for High Precision Gantry Stage

Ph.DDOCTOR OF PHILOSOPH