Slide# Ketter Hall, North Campus, Buffalo, NY Fax: Tel: x 2400 Control of Structural Vibrations Lecture #7_2 Active Control - Special Algorithms Instructor: Andrei M. Reinhorn P.Eng. D.Sc. Professor of Structural Engineering
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Slide# 3 Issues in Active Control Control Logic - Algorithms Control Considerations - Stability, etc. Control Implementations - Force Generation Physical Implementations Full Scale Implementations
Slide# 4 Control Considerations Stability Controllability Observability
Slide# 5 Reduced Order Models
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Slide# 7 Stability of Control Addition of energy to system Control may produce “negative” damping
Slide# 8 Stability of Control
Slide# 9 Stability of Control
Slide# 10 Stability of Control
Slide# 11 Stability of Control
Slide# 12 Stability of Control
Slide# 13 Stability of Control
Slide# 14 Controllability Is it possible to modify the state (displacement and velocity) of system under the control input? For: R must have rank n n x nm
Slide# 15 Controllability
Slide# 16 Controllability
Slide# 17 Controllability above
Slide# 18 Observability Is it possible to determine the state, z, variables if the control forces, u, and the output vector, y, is known Must have rank n rn x n
Slide# 19 Observability
Slide# 20 Issues in Active Control Control Logic - Algorithms Control Considerations - Stability, etc. Control Implementations - Force Generation Physical Implementations Full Scale Implementations
Slide# 21 Control Implementations Force Generation Time Delay Robustness
Slide# 22 Time Delay Effect
Slide# 23 Time Delay Effect
Slide# 24 Time Delay Effect
Slide# 25 Time Delay Effect
Slide# 26 Time Delay Effect
Slide# 27 Time Delay Effect
Slide# 28 Time Delay Effect
Slide# 29 Time Delay in Feedback Vectors
Slide# 30 Time Delay Compensation
Slide# 31 Time Delay - Phase Lag = or [sec]= /2 f [Hz]
Slide# 32 Issues in Active Control Control Logic - Algorithms Control Considerations - Stability, etc. Control Implementations - Force Generation Physical Implementations Full Scale Implementations
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Slide# 34 Three Stories Controlled Model
Slide# 35 Active Tendon System
Slide# 36 Control Equipment
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Slide# 38 Structural Properties
Slide# 39 Instrumentation
Slide# 40 Control System of Three Stories Structure
Slide# 41 Control Properties
Slide# 42 Transfer Functions
Slide# 43 Challenges
Slide# 44 First Floor Response
Slide# 45 Second Floor Response
Slide# 46 Third Floor Response
Slide# 47 First Floor Response
Slide# 48 Second Floor Response
Slide# 49 Third Floor Response
Slide# 50 Summary of Three Stories Model - System Uncontrolled Controlled Modal Frequencies (Hz) Modal Damping Factors (%)
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Slide# 58 Characteristics of Six Stories Model - System
Slide# 59 Six Stories Model - Control Configurations
Slide# 60 Six Stories Model - Control Configurations ExperimentalSimulations
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Slide# 64 Comparison of AMD abd ATS/ABS
Slide# 65 Estimates of Full Scale
Slide# 66 Issues in Active Control Control Logic - Algorithms Control Considerations - Stability, etc. Control Implementations - Force Generation Physical Implementations Full Scale Implementations
Slide# 67 Full Scale Implementations
Slide# 68 Full Scale Implementations
Slide# 69 Six Story Test Structure
Slide# 70 ABS Actuator Detail
Slide# 71 Control System Components
Slide# 72 Significant Results System operational for one year. Verified with forced vibrations. Subjected to three earthquakes. –Magnitudes of 4.9 to 5.6. System performed well. –Moderate reduction of the peak response. –Excellent reduction of the RMS intensity of the response. Not operational during fourth earthquake due to a hardware failure.
Slide# 73 Response of Controlled Structure
Slide# 74 Lessons Learned Active bracing systems can be implemented with current technology. System has reasonable energy requirements. Need for improvements: –Linear controller not effective on first response peak. –Need redundancy in the control hardware. Learned a great deal about computer and digital hardware communication.
Slide# 75 Control Algorithms Method 1: Optimal Control Method 2: Poles Assignment Method 3: Instantaneous optimum Method 4: Independent Modal Space Control Method 5: Bounded State Control Method 6: H 2 and H Control Method 6: H 2 and H Control Method 7: Sliding Mode Control Method 8: Fuzzy Logic Control
Slide# 76 Control Algorithms Method 1: Optimal Control Method 2: Poles Assignment Method 3: Instantaneous optimum Method 4: Independent Modal Space Control Method 5: Bounded State Control Method 6: H 2 and H Control Method 7: Sliding Mode Control Method 7: Sliding Mode Control Method 8: Fuzzy Logic Control
Slide# 77 Control Algorithms Method 1: Optimal Control Method 2: Poles Assignment Method 3: Instantaneous optimum Method 4: Independent Modal Space Control Method 5: Bounded State Control Method 6: H 2 and H Control Method 7: Sliding Mode Control Method 8: Fuzzy Logic Control
Slide# 78 Linear and Nonlinear Control