Book contents
- Vibration Protection Systems
- Vibration Protection Systems
- Copyright page
- Contents
- Preface
- Acknowledgments
- Glossary
- 1 Vibrations Destroying Human–Machine Systems Inside and Outside
- 2 Vibration Protection Systems with Negative and Quasi-Zero Stiffness
- 3 Modeling of Elastic Postbuckling in Large and Dimensioning the Mechanisms with Negative Stiffness
- 4 The Type and Number Synthesis of Function-Generating Mechanisms
- 5 Dynamics of Systems with Sign-Changing Stiffness
- 6 Dynamics of Systems with Sign-Changing Stiffness
- 7 Dynamics of Systems with Sign-Changing Stiffness
- 8 Methods of Experimental Study of Vibration Protection Systems with Negative and Quasi-Zero Stiffness
- 9 In Harmony with Conventional Vibration Protection Systems
- 10 Development and Use of Vibration Protection Systems with Negative and Quasi-Zero Stiffness
- Index
- References
7 - Dynamics of Systems with Sign-Changing Stiffness
Features of Active Parametric and Motion Control
Published online by Cambridge University Press: 29 October 2021
- Vibration Protection Systems
- Vibration Protection Systems
- Copyright page
- Contents
- Preface
- Acknowledgments
- Glossary
- 1 Vibrations Destroying Human–Machine Systems Inside and Outside
- 2 Vibration Protection Systems with Negative and Quasi-Zero Stiffness
- 3 Modeling of Elastic Postbuckling in Large and Dimensioning the Mechanisms with Negative Stiffness
- 4 The Type and Number Synthesis of Function-Generating Mechanisms
- 5 Dynamics of Systems with Sign-Changing Stiffness
- 6 Dynamics of Systems with Sign-Changing Stiffness
- 7 Dynamics of Systems with Sign-Changing Stiffness
- 8 Methods of Experimental Study of Vibration Protection Systems with Negative and Quasi-Zero Stiffness
- 9 In Harmony with Conventional Vibration Protection Systems
- 10 Development and Use of Vibration Protection Systems with Negative and Quasi-Zero Stiffness
- Index
- References
Summary
Most routine strategies of motion control in vibration protection systems are based on attenuation of resonant responses using external semi-active or active dampers. In the systems with negative and quasi-zero stiffness, it is simpler because there is no need to know and continually process random signal data from an external vibration source. The control focuses on maintaining a certain balance between the positive and negative stiffness of parametric elements varied in predetermined ranges to keep separation of the system natural frequency spectra and the frequencies of forced vibrations including near-zero values. The control criteria, formulated and quantitatively estimated, provide extremely small stiffness, immobility in a steady state motion, and stabilization in a transient motion of the system without an external damper. The control strategy is validated through designing the systems supplied with active pneumatic suspensions and passive mechanisms of variable negative stiffness. The control algorithms were realized with the help of a two-channel control system and actuators made of commercial hardware and operating in parallel. Efficiency of the algorithms has been estimated through comparison of results of computer simulation and development test of seat suspensions for vibration protection of drivers of heavy trucks and buses and for helicopter pilots.
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- Vibration Protection SystemsNegative and Quasi-Zero Stiffness, pp. 172 - 200Publisher: Cambridge University PressPrint publication year: 2021