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This article aims to analyze the differences between 3 of the CVX toolbox canonical solvers: SDPT3, SeDuMi and ECOS; for problem formulations based on lossless convexification technique (LCvx). Without loss of generality, the simulations were conducted on the first stage of the launcher Falcon 9, while the goal of the optimization process is to minimize the fuel consumption through minimization of the total thrust under restrictions based on physical limitations of the vehicle.

The Aerospace Plane Research Center at the Muroran Institute of Technology is currently conducting research to develop enabling technologies for high-speed aircraft traveling at high altitudes and constructing experimental, small-scale, unmanned supersonic aircraft called Oowashi as a testbed for flight. To confirm the control performance of the aircraft, an experiment using a one-third-scale model of the Oowashi aircraft has been planned. The flight of high-speed aircraft always presents the problem of having to land on an ordinary runway regardless of the aircraft’s high speed at the beginning of the landing process. This paper therefore proposes a new landing control design method that can shorten the landing distance for a high-speed aircraft without increasing the rate of descent. The design method utilizes the newly clarified relationship between an angle of attack and the time constant of flare control system, which is effective to raise glideslope angle during landing. The validity of the method is confirmed by computer simulation assuming the model aircraft equivalent to a one-third-scale model of the Oowashi aircraft.

This paper proposes a modified glideslope guidance method that optimizes a hybrid multiobjective of bearing-only navigation error and fuel consumption. The traditional glideslope guidance fixes uniform maneuver intervals and the initial approach velocity as a predetermined value, making this approach inflexible. In this paper, the maneuver intervals and the initial approach velocity were used as optimization variables, and a hybrid cost function was designed. The tradeoff between the two objectives was analyzed with a bearing-only navigation simulation conducted to reveal the navigation performance following different resulting trajectories. The result showed that the optimal scheduled times of maneuvers remained relatively stable under different tradeoff weights, while a strong correlation between the optimal initial approach velocity and the tradeoff weight was revealed. Therefore, when the optimization has to be solved several times online with different tradeoff weights, the initial approach velocity can be the only optimization variable, leaving the scheduled times of maneuvers fixed in the optimal values achieved offline. These findings provide a potential reference for far-approach trajectory design of bearing-only navigation.

The guidance and control problem of spacecraft approaching an asteroid using constant continuous thrust is studied in this work. The range of interest is from hundreds of kilometers to several kilometers, in which relative measurements of much higher accuracy than based on Earth can be used to facilitate further hovering or landing operations. Time-fixed glideslope guidance algorithm is improved by introducing a substitute of an existing control parameter and combined with elliptical relative orbital dynamics to rendezvous the spacecraft with a prescribed location in the proximity of a given asteroid. A vast range of values for the control parameters are explored and suitable combinations are found. To fully validate the robustness and accuracy of the proposed control algorithm, Monte Carlo simulations are done with the navigational error and implementation error considered.

the unstable approach caused by the distortion of glideslope, endangers aircraft in the forms of over-pitching, stalling at low altitude, and exceeding the limitation of descent rate. Aiming at the issues above, this paper presents a glideslope distortion correction model based on the fusion of multi-navigation sensors. Model simulations have been done to prove the effectiveness of the model, and the results show that the correction model can enhance the stability of glideslope effectively.

Instrument landing system (ILS) is a very important navigational aid at most major airports of the world. However, their performance is directly affected by the features of the site in which they are located. Since the on-site validation of the ILS performance is normally done through costly and time consuming experimental methods, considerable efforts have been made in the past to develop analytical approaches as an alternative to the experimental methods. This paper though follows the earlier approaches of multi-plate terrain modeling, presents a very powerful and exhaustive ray tracing technique and a modified formulation for determining the electromagnetic fields. Innovative techniques are introduced at each stage to make the model versatile enough to handle the effects of the undulation, the roughness and the impedance of the terrain and also to reduce computational requirements to a minimum. The results obtained from the method developed here are compared with the earlier methods and the actual measurements and good agreement is shown.