Abstract
Non-planar sensor arrays are used to determine solar orientation based on the orientation matrix formed by orientation vectors of the sensor planes. Solar panels or existing photodiodes can be directly used without increasing the size or mass of the spacecraft. However, a limiting factor for the improvement of the accuracy of orientation lies with the lack of an assessment-based approach. A formulation was developed for the supremum (i.e., the least upper bound) of orientation error of an arbitrary orientation matrix in terms of its influencing factors. The new formulation offers a way to evaluate the supremum of orientation error considering interference with finite energy and interference with infinite energy but finite average energy. For a given non-planar sensor array, a sub-matrix of the full orientation matrix would reach the optimal accuracy of orientation if its supremum of orientation error is the least. Principles for designing an optimal sensor array relate to the configuration of the orientation matrix, which can be pre-determined for a given number of sensors. Simulations and field experiment tested and validated the methods, showing that our sensor array optimization method outperforms the existing methods, while providing a way of assessment and optimization.
Highlights
Determination of solar orientation is a critical technique that has a wide range of applications, including spacecraft attitude estimation [1,2] assisted positioning for planetary rovers [3] ground-based navigation systems [4] and efficiency improvement of solar power plants [5]
The rest of this article is organized as follows: Section 2 introduces the method for orientation determination of the Sun based on non-planar sensor arrays; Section 3 establishes the relationship between the orientation error and its influencing factors; Sections 4 and 5 present the orientation performance assessment and optimization, respectively; Section 6 provides verification of the assessment and optimization method by means of simulation and field experiment; Section 7 concludes this study with summary and discussions
We developed a theoretical formulation for the supremum of the orientation error of an arbitrary orientation matrix with more than three non-coplanar sensors
Summary
Determination of solar orientation is a critical technique that has a wide range of applications, including spacecraft attitude estimation [1,2] assisted positioning for planetary rovers [3] ground-based navigation systems [4] and efficiency improvement of solar power plants [5]. At least three such sun sensors are required to determine the Sun’s position for full view-field applications This requirement leads to an increased load for small aerospace equipment such as nano-satellites, which is problematic because of their limited size, weight, and power supply. Another primary method in solar orientation determination is based on non-planar sensor arrays that are formed by photodiodes equipped on different surfaces of spacecrafts [1,2,11] or sometimes by Sensors 2019, 19, 2561; doi:10.3390/s19112561 www.mdpi.com/journal/sensors. The rest of this article is organized as follows: Section 2 introduces the method for orientation determination of the Sun based on non-planar sensor arrays; Section 3 establishes the relationship between the orientation error and its influencing factors; Sections 4 and 5 present the orientation performance assessment and optimization, respectively; Section 6 provides verification of the assessment and optimization method by means of simulation and field experiment; Section 7 concludes this study with summary and discussions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
