Stewart active platform and a vibration abatement method based on the Stewart active platform

Abstract

The present invention discloses a Stewart active platform and a vibration abatement method. The Stewart active platform includes a load platform, a basic platform, a controller, an acceleration sensor and piezoelectric single-legged structures. Each piezoelectric single-legged structure includes an upper flexible hinge, a force sensor, a piezoelectric actuator, and a lower flexible hinge. The force sensor, the piezoelectric actuator and the acceleration sensor are connected to the controller. The method includes the steps as follows: 1) the controller acquires a feedback control signal; 2) the controller acquires a feedforward control signal; 3) the controller acquires a composite control voltage of a feedback voltage and a feedforward voltage; 4) and the composite control voltage is outputted to the piezoelectric actuator, and the piezoelectric actuator applies an acting force to the load platform. A control algorithm adopted by the invention, which utilizes a PI force feedback algorithm, not only can effectively reduce a natural system frequency and a vibration resonance peak, but also efficiently iterate by the utilization of an RLS adaptive algorithm with an efficient evaluation performance so as to find an optional weight value, and thereby reducing the vibration of the load platform.

Description

technical field [0001] The invention belongs to the field of vibration control, and more specifically relates to a Stewart active platform and a vibration suppression method based on the Stewart active platform. Background technique [0002] In vibrating systems, passive vibration isolation presents a reliable, low-cost solution that effectively attenuates high-frequency vibrations over a wide frequency band. However, due to two inherent contradictions in the vibration isolation system: the contradiction between the vibration attenuation capabilities in the high and low frequency bands, the contradiction between the vibration isolation capability of the foundation and the ability to resist the direct interference of the foundation, it cannot meet the requirements of ultra-precision equipment isolation. For example, the spacecraft flying in orbit is not in a state of free drift (weightlessness), and various responses will cause disturbances similar to the acceleration of grav...

AI Technical Summary

Problems solved by technology

[0003] Compared with passive theory, active vibration isolation produces significant performance enhancements, but it requires sensors, actuators, algorithm processors, which requires active vibration isolation to be reliable and efficient in terms of load and power consumption

Although pure active feedback control can effectively solve the first inherent contradiction of vibration isolation performance, the active algorithm is still not efficient enough to solve the second contradiction in the vibration isolation system, and cannot meet the precise vibration isolation requirements of satellite platforms

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