Research On Pneumatic Active Isolation Control Strategy For Single Axial Flexible Payload

Flexible bodies widely exists in spacecraft, comparing to rigid body, this kindstructure can prolong spacecrafts’ life span and achieve sophisticated function, suchas data acquiring device, camera and solar panel on the satellite platform.Pneumatic vibration isolation system has an outstanding performance referring tovibration isolation; it can guarantee the precision of devices, safety and enhance thecomfort of riding. In practical application, pneumatic vibration isolation systemoften shows nonlinearity, this would affect the performance of device, could evendamage the device. This paper studied the pneumatic vibration isolation system withflexible payload, considered the nonlinearity brought in by the charging/releasingprocess of the air chamber.This paper established the dynamic model of the pneumatic vibration isolationsystem with flexible payload, analyzed system’s passive transmissibility, usingpayload acceleration feedback, base acceleration feed-forward and the combinedway to active control the vibration isolation system. Through comparing system’scontrolled transmissibility with passive transmissibility, finding that the activecontrol could attenuate the resonant peak significantly and lower thetransmissibility.Then, this paper used the adaptive filter algorithm to study the vibrationisolation of the system. Through the simulation of the single and double frequencyexcitation, I find that after the single point recognition, the adaptive algorithm couldsuppress the point’s vibration very well; aiming at the vibration isolation of randomexcitation, this paper put forward a new recognition approach, using this methodcould achieve good vibration isolation performances while only using a singleoff-line recognition, this achieved the vibration isolation of all frequency range; inaddition, this paper discussed the different vibration isolation performancesregarding two cases of when using the interface unit’s output as system’s output andusing the weighting output as system’s output, finding that the vibration isolationperformance has a further improvement after weighting.This paper also brought in the nonlinearity caused by the charging/releasingprocess of air cavity, studied system’s vibration isolation performance undersingle/double harmonic excitation, result suggested that the adaptive filter algorithmcould control the frequency doubling phenomenon well.