*From:* "Dumanli, Alper" <dumanlia@oregonstate.edu> *Date:* March 15, 2021 at 8:16:44 PM PDT *To:* "Sencer, Burak" <Burak.Sencer@oregonstate.edu> *Subject:* *Re: Alper Dumanli - PhD Defense - Thursday, March 18, 10am*  Hi all, Alper Dumanli will be defending his PhD dissertation on Thursday (March 18th) at 10am. Below are the details, hope to see you there! *Date and Time: *Thursday, March 18, 10am *Title: *Active and Passive Control of Machine Tool Vibrations for High Speed and Accuracy *Abstract:* High-performance mechatronic systems are widely used in precision manufacturing equipment such as CNC machine tools, 3D-Printers, photolithography systems, and industrial robots. To keep up with the rapidly increasing productivity and accuracy demands, it is crucial that mechatronic systems (feed drives) of these manufacturing equipment deliver high-speed motion with high precision. In this dissertation, motion control strategies are presented to increase dynamic positioning accuracy and productivity of such systems. First, a novel trajectory generation method is presented to avoid exciting low frequency structural vibration modes, without compromising from productivity. Trajectory generation problem is posed as a convex optimization problem, and a practical windowing method is presented to implement the proposed strategy in real-time for realistic manufacturing scenarios. Next, a data-driven trajectory shaping algorithm is designed to eliminate dynamic positioning errors induced by flexible motion transmission components (such as ball screw drives) and nonlinear friction forces typically caused by mechanical bearings and guiding units. The proposed algorithm is used for optimizing trajectory pre-filters through machine-in-the-loop iterations, and therefore it can be applied on a wide variety of systems without elaborate dynamic modeling. Finally, an active tool position control strategy is proposed to mitigate chatter vibrations for improving stability margins of turning processes. Two motion control algorithms are developed to control the dynamic interaction between the tool and the workpiece. Effectiveness of the proposed strategies is demonstrated on machine tools by high-speed tracking and machining experiments. *Location:* Zoom meeting link below: https://oregonstate.zoom.us/j/9759813712?pwd=aGZZSVc2ck53N3pqUW1uOGFFWXNUZz0... <https://www.google.com/url?q=https://oregonstate.zoom.us/j/9759813712?pwd%3DaGZZSVc2ck53N3pqUW1uOGFFWXNUZz09&sa=D&source=calendar&ust=1616295884490000&usg=AOvVaw2znxIgAlznfm8cNNLko-qr> Password: mime97331 Phone Dial-In Information +1 971 247 1195 US (Portland) +1 253 215 8782 US (Tacoma) +1 301 715 8592 US (Washington D.C) Meeting ID: 975 981 3712