Optimization method of small thrust transfer trajectory for asteroid detection based on successive convex programming

Abstract

The invention discloses a small-thrust transfer trajectory optimization method for asteroid detection based on successive convex programming, which belongs to the field of aerospace technology. The realization method of the invention is as follows: establishing an improved vernal equinox dynamics model for the small thrust transfer of the asteroid probe. According to the dynamic characteristics of low-thrust transfer, the constraints and optimization performance indexes of the low-thrust trajectory optimization problem are given. The specific form of the low-thrust interstellar transfer trajectory optimization problem is given. The nonlinear small thrust transfer problem is convexized by dynamic linearization and nonlinear equality constraint relaxation. The continuous optimal control problem after convexization is transformed into a convex optimization problem by numerical integration. Taking the sub-problem after convexization as the inner link of each iteration step, the optimal small-thrust transfer trajectory for asteroid detection can be obtained quickly by using the successive approximation strategy in a limited number of steps, that is, the optimality and accuracy of the low-thrust trajectory can be guaranteed. Under this condition, the online optimization of the low-thrust trajectory is realized. The invention has strong robustness, high repeatability and high flexibility.

Description

technical field [0001] The invention relates to a small-thrust transfer trajectory optimization method for asteroid detection based on successive convex programming, in particular to a transfer trajectory optimization method suitable for interstellar transfer missions of asteroid probes, and belongs to the field of aerospace technology. Background technique [0002] Asteroid detection is a hot spot for human deep space activities. Since asteroids contain the original information of the universe, the detection of asteroids can greatly improve human understanding of the origin and evolution of the universe. In the asteroid exploration mission, due to the long flight distance, the probe needs to carry more fuel to ensure that the probe can reach the target asteroid and carry out subsequent missions. However, limited by the launch capability of the existing launch vehicle, the asteroid probe The total weight is severely limited, and sufficient fuel reserves will inevitably reduc...

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Problems solved by technology

[0005] Prior technology [2] (see: Wang Z, Grant M J. Minimum-fuel low-thrust transfers for spacecraft: a convex approach [J]. IEEE Transactions on Aerospace and Electronic Systems, 2018, 54(5): 2274-2290. ) gave a small thrust transfer trajectory optimization method based on convex optimization. Although this method has high computational efficiency, it is difficult to give the initial value of the solution, and it is difficult to determine the optimality of the results obtained by the method

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