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In this work, an active hybrid mount using piezostack actuator and rubber element is manufactured, and its vibration control performance is evaluated via feedforward control. A hybrid active mount featuring inertia type of piezostack actuator is proposed and manufactured. After describing the configuration of the hybrid mount, a mount system is then constructed. To attenuate vibrations from vibration sources, a feedfoward controller is experimentally implemented to the system. Vibration control performances are evaluated at each mount. Effective control performances such as accelerations are obtained and presented in frequency domains.

A hybrid mount for shipboard machinery installed on naval ships was developed. The mount is combined with a rubber mount and a piezostack actuator. The rubber mount is one of the most popular and effective passive mounts to have been applied to various vibration systems to date. The piezostack actuator is featured by a fast response time, small displacement and low power consumption. Through a series of experimental tests conducted in accordance with MIL-M-17185A(SHIPS), MIL-M-17508F(SH), and MIL-S-901D which are US military specifications related to the performance requirements of the mount, it has been confirmed that the hybrid mount shows more effective performance for use in naval ships. * 1. 서 론 기술의 진보와 함께 항공기, 선박, 자동차 등 수송기계시스템에 탑재되는 장비의 성능사양 뿐만 아니라 소음, 진동 및 충격 등 특수성능 사양도 강화되고 있다. 특히 잠수함과 같은 해군 함정의 경우 생존성 분야 연구의 증가와 함께 고정도 스텔스 성능확보 및 탐지에 대한 사양이 강화되고 있다. 함정에 탑재되고 있는 각종 기계/전자 장비들을 살펴보면, 장비 하부에 다양한 형태의 마운트가 설치되어 있는 것을 알 수 있다. 이러한 마운트 설치의 목적†교신저자; 정회원, 한국기계연구원E-mail : sjmoon@kimm.re.krTel : (042)868-7428, Fax : (042)868-7418* 한국기계연구원** 정회원, 인하대학교*** 국방과학연구소**** 국방과학연구소 민군겸용센터은 첫째 탑재장비에서 발생하는 진동 및 소음이 하부 구조물로 전달되는 것을 차단함으로서 함내 거주성을 향상시키고, 적으로부터 탐지되는 확률을 저감시키는 데 있다. 둘째는 적으로부터의 공격 등 외부 충격으로부터 장비를 보호함으로서 함정의 작전능력을 항시 유지하는 데 있다.현재 사용되고 있는 함정 탑재장비용 마운트는 대부분 수동형 마운트로서 고무 또는 와이어의 탄성특성을 이용하는 탄성 마운트이다. 이러한 탄성 마운트는 작은 감쇠특성을 보유하고 있으며, 고주파수의 비공진 주파수 대역에서는 우수한 진동절연 성능을 보이고 있다. 그러나 탑재장비가 자체 기진력이 있는 경우에는 탑재장비의 기진력으로 인하여 특정 주파수에서 진동이 현저하게 나타날 수 있으며, 수동형 마운트로서는 만족스러운 결과를 얻기 어렵다. 이러한 경우에는 능동형 마운트를 고려할 수 있으나, 함정과 같이 입력되는 진동이 큰 경우에는 큰 제어력이 필요하게 되며, 일반적으로 수동형

This paper presents vibration control of an active hybrid engine mount featuring a magneto-rheological(MR) fluid and a piezostack actuator. The MR fluid is adopted to improve isolation performance at resonant frequencies, while the piezostack actuator is adopted for performance improvement at non-resonant frequencies, especially at high frequencies. Based on some particular practical requirements of engine mounts, the proposed mount is designed and manufactured. The characteristics of rubber element, piezostack actuator and MR fluid are verified for system analysis and controller synthesis. The dynamic model of the proposed mount with a supported mass (engine) is established. In this work, a sliding mode controller is synthesized for the mount system to reduce vibrations transmitted from the engine in a wide frequency range. Computer simulations are performed to evaluate control performances of the proposed active engine mount in time and frequency domains.

This paper presents active vibration control performance of a hybrid mount. The proposed hybrid mount is devised by adopting both piezostack as an active actuator and rubber as a passive element. After experimentally identifying actuating force characteristics of the piezostack and dynamic characteristics of the rubber, the hybrid mount was designed and manufactured. Subsequently, a vibration control system with a specific mass loading is constructed, and its governing equations of motion are derived. In order to actively attenuate vibration transmitted from the base, a feedforward controller is formulated and experimentally realized. Vibration control responses are then evaluated in time and frequency domains.