Error compensation method for Mars rover APS sun sensor

Abstract

The invention relates to an error compensation method for a Mars rover APS sun sensor. According to the method, the coordinates of the mass center of a solar hot spot are corrected by using the idea of camera distortion correction, a cubic polynomial of the theoretical coordinate position and the actual mass center position of the mass center of the solar hot spot is established, and the coefficient of the cubic polynomial is obtained by using a least square method; An angle residual error after coordinate compensation is solved by adopting a secondary compensation thought, and the problem of rapid positioning of an angle compensation curve is solved. The calculation amount is reduced to two times of third-order polynomial calculation and two times of seventh-order polynomial calculation, the precision reaches 0.03 degree (3 sigma) after error compensation, the calculation amount is reduced, the product updating rate is increased, and the product precision is improved.

Description

technical field [0001] The invention belongs to the field of optical attitude sensors, and relates to an error compensation method for an APS sun sensor of a Mars rover. Background technique [0002] The sun sensor is an optical attitude sensor that measures the angle between the spacecraft attitude and the sun's ray vector, taking the sun as the reference orientation. The sun sensor on the rover measures the direction of the sun vector, which provides yaw pointing for the rover on the surface of Mars, ensures that the rover moves in the predetermined direction, and at the same time completes the correction of the long-term drift of the gyro. [0003] The area array APS CMOS image sensor used in the sun sensor of the Mars rover is used as a photodetector. The small hole on the light introducer is used to realize light introduction. The sunlight reaches the APS image sensor through the small hole to form a bright sun spot. The energy center of the bright spot can determine t...

AI Technical Summary

Problems solved by technology

[0005] During the development of the APS solar sensors of Chang'e-3 and Chang'e-4, when the angle error compensation is carried out, the error introduced by refraction and assembly reaches more than 5°, and it needs to be compensated to within 0.1°, which requires 7th-order polynomial operations to be performed 7 times , similar to patent CN103411580A (two-axis angle determination method in linear array APS sun sensor), this 7-degree polynomial operation needs to be iteratively compensated for multiple times to select a suitable compensation curve, and when selecting the compensation curve, according to the angle measurement The value is weighted between two adjacent compensation curves, that is, the compensation value is calculated by weighting and summing the two error compensation polynomials, which leads to too long operation time of the single-chip microcomputer 80C32E inside the single machine, and the product update rate is low, only 2Hz. The angle compensation operation has to be completed by the high-performance CPU inside the integrated electronics

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