Compensation method based on generalized inner module for eccentric torque of three-shaft inertially stabilized platform

Abstract

A compensation method based on a generalized internal module for eccentric torque of a three-shaft inertially stabilized platform includes establishing a state-space equation of a control system of the three-shaft inertially stabilized platform, measuring angular rate information of the platform in real time by the aid of a rate gyroscope, measuring current information in real time by the aid of a current sensor, implanting a joint unstable module of reference input and the eccentric torque into the system, and achieving the purpose of unsteady-state error tracking control by the aid of generalized inner module control algorithm. An internal module controller comprises a servo compensator and a stabilized compensator. By the aid of the compensation method, disturbance attenuation capacityis improved, unsteady-state error tracking is realized, and a high robust performance is realized.

Description

technical field [0001] The invention relates to an eccentric moment compensation method for a three-axis inertial stable platform based on a generalized internal model, which belongs to the field of high-resolution aerial earth observation systems and can be used for static-difference-free tracking control of a three-axis inertial stable platform with high stability requirements, especially It is suitable for light and small high-resolution aerial remote sensing three-axis inertial stabilization platform. Background technique [0002] The inertial stabilization platform is a necessary equipment for realizing high-resolution earth observation. It can effectively isolate the disturbance and non-ideal attitude movement of the flight platform, so that the observation load's boresight pointing and heading always maintain inertial space stability. At present, the representative foreign products are PAV30 and PAV80 of Swiss Leica Company, while domestic related research has just st...

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Problems solved by technology

[0003] Ideally, it will not be affected by the disturbance torque, and the stable platform will always maintain the stability of the inertial space. However, due to factors such as actual processing errors and uneven counterweights, the center of mass of the platform and the axis of the frame are not concentric, and there is a certain eccentricity. Therefore, in the acceleration of gravity Under the influence of eccentric torque and motion disturbance acceleration, the motion of the platform will be affected by the eccentric torque, which will affect its performance indicators such as its stability accuracy; the greater the mass, eccentric distance, and motion disturbance acceleration, the greater the eccentric torque, and the worse the stability accuracy, so it is necessary to adopt Measures to restrain the effect of eccentric moment

For the compensation method of the eccentric moment of the inertial stable platform, a patent has been applied for "a method for estimating and compensating the unbalanced moment of the aerial remote sensing inertial stable platform" (application number 200910241242.9). This method uses the MEMS accelerometer installed on the platform Measure the celestial acceleration and motion disturbance acceleration, use the low-pass filtering method to filter the current information, estimate the eccentric torque, and use the feedforward method to compensate, which can suppress the effect of the eccentric torque to a certain extent, but there are the following three Insufficient aspects: first, for the three-axis inertial stabilization platform, three MEMS accelerometers need to be installed on each frame by this method, and the volume and mass of the platform will increase accordingly, which is not conducive to its light and small structure design; second, The bias stability and repeatability of the MEMS accelerometer are poor, the measured value contains large noise, and unknown disturbance factors are introduced during feedforward compensation; third, for the real-time control system of the platform, the Butterworth low-pass filter is relatively Difficult to implement, and the low-pass filter will affect the disturbance suppression ability

Therefore, in summary, this method is physically difficult to implement, which directly limits the application ability in actual work

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