Vibration characteristics of multi-dimensional isolator based on 4-PUU parallel mechanism with joint clearance

For isolating multi-dimensional vibration experienced by vehicle-mounted precise facility, a multi-dimensional vibration isolator based on parallel mechanism with joint clearance is designed and analyzed. The main thrust of this work is establishing kinematic and dynamic equations of the isolator and exploring vibration isolation capability with joint clearance. Firstly, type synthesis of the parallel mechanism with three translations and one rotation is performed. The kinematic and dynamic equations of the isolator with joint clearance are deduced. Subsequently, vibration isolation performance is simulated with different values of joint clearance under harmonic and stochastic excitations in time and frequency domain, respectively. The simulating results demonstrate the proposed isolator with joint clearance inhibit multi-dimensional vibration effectively. The first-order resonance peak is sensitive to the increment in joint clearance. Finally, the proposed multi-dimensional vibration isolator is fabricated. The vibration isolation experiment is conducted. Through experimental results, the isolator reduces multi-dimensional vibration effectively in time and frequency domain. The vibration isolation capability degenerates as the counterweight of moving platform increases.

Automated summary

In this study, a multi-dimensional vibration isolator based on a parallel mechanism with joint clearance is designed and analyzed to isolate the multi-dimensional vibration experienced by a vehicle-mounted precise facility. The kinematic and dynamic equations of the isolator with joint clearance are established, and the vibration isolation capability is explored through simulation and experimentation. The results demonstrate that the proposed isolator effectively inhibits multi-dimensional vibration, with the first-order resonance peak being sensitive to the increment in joint clearance.