[기계]Sensing Rich Design and Relay Feedback Stability for Controlled Mechanical Systems

1. 제 목 : Sensing Rich Design and Relay Feedback Stability for Controlled Mechanical Systems

2. 연 사 : 전 수 박사(Applied Materials Inc.)

3. 일 시 : 2009년 1월 5일(월) 16:00 ~ 17:00

4. 장 소 : 301동 1512호

5. 내 용 :
This talk addresses two particular issues arising in controlled mechanical systems: state estimation based on kinematic model using more sensors and the unified approach to understand the nonlinear dynamics coming from Coulomb friction.
Recent advances in sensor technologies raise basic questions on how we synthesize information from sensors and how we implement it in a reliable and cost effective manner. The first part of this talk deals with these issues from the state estimation point of view by exploiting the sensor-based estimation method called kinematic Kalman filter (KKF). The KKF refers to the Kalman filter applied to a kinematic model. Being independent of physical parameters, the KKF is immune to modeling uncertainties and parameter variations. In its simplest form, the KKF combines an encoder with an accelerometer to provide robust and accurate velocity estimation. This simple idea is then extended to a general rigid body motion leading to the formulation of the multi-dimensional KKF (MD-KKF). The MD-KKF combines the measurements from the vision sensor, accelerometers and gyroscopes to remedy the inherent limitations of the machine vision, i.e., the slow sampling rate and the latency.
In control of mechanical systems with drive trains, the Coulomb friction is an important nonlinearity not only as the source of tracking error but also as the cause of instability generating nonlinear oscillations called limit cycles. The second part of this talk focuses on the latter. First, we show that a series of drive trains with multiple Coulomb friction sources can be formulated as a special class of relay feedback systems characterized by the zero DC gain property and the positivity of the first Markov parameter. Then, employing the piecewise quadratic Lyapunov (PWQL) function and the integral quadratic constraint (IQC), new sufficient conditions are derived to guarantee the pointwise global stability. The results are used to design mechanical systems free from limit cycles.

6. 연사약력 :
- 현재 Systems Engineer, Dielectric Systems & Modules, Applied Materials Inc. Santa Clara CA
- 2007 Ph.D., Dept. of Mechanical Engineering, University of California at Berkeley
- 2001 M.S., Dept. of Mechanical & Aerospace Engineering, Seoul National University
- 1998 B.S., Dept. of Mechanical Design & Production Engineering, Seoul National University

7. 문 의 : 기계항공공학부 조규진 교수(☏ 880-1703)