GNC system scheme for lunar soft landing spacecraft

Autonomous celestial navigation for a deep space probe approaching a target planet based on ephemeris correction

“…Notation A bc transformation matrix from the sensor coordinate system to the body coordinate system A bc transformation matrix from the sensor coordinate system to the body coordi- pixel coordinate of the origin of the pixel and line coordinate system in the image P 0 initial covariance matrix Q process noises covariance matrix r position vector of the probe in the Mars-centered inertial system r i position vector of the i th planet in the Mars inertial coordinate system r i distance between the i th planet and the target planet r p i position vector of probe with respect to the i th planet r pi distance between the probe and the i th planet r ps distance between the probe and Sun r pt distance between the probe and the planet r s position vector of Sun in the Mars inertial coordinate system r s distance of Sun in the Mars inertial coordinate system r t position vector of the probe with respect to the target r t distance between the probe and the target r a t distance from the probe to the actual target r p t distance from the probe to the planned target r helio position vector of the probe in heliocentric inertial coordinate system r target velocity vector of the probe target-centered inertial coordinate system r helio target position vector of the target in the heliocentric inertial coordinate system R measurement noise covariance matrix R x à ð Þ rotation matrix R target radius of the target R a image radius of the target image in the 2D image frame coordinates system v velocity vector of the probe in the Mars-centered inertial system v helio velocity vector of the probe in the heliocentric inertial coordinate system v target velocity vector of the probe in the target-centered inertial coordinate system v helio target velocity vector of the target in the heliocentric inertial coordinate system v x velocity of the probe in X-axis of the target-centered inertial system v y velocity of the probe in Y-axis of the target-centered inertial system v z velocity of the probe in Z-axis of the target-centered inertial system V measurement noise vector V a augmented measurement noise vector V k white, zero-mean, uncorrelated measurement noise at the kth step w process noise vector in the three-axis velocity direction of the probe w B process noise of the ephemeris bias model w 1 ,w 2 ,w 3 process noise in _ x, _ y, _ z w 4 ,w 5 ,w 6 process…”

An innovative navigation scheme of powered descent phase for Mars pinpoint landing

“…Vision-aided navigation can provide the horizontal position by detecting craters or other points of interest in the landing site and matching to a stored landmark database (Janschek et al, 2006;Pham et al, 2009;Yu et al, 2014;Wang et al, 2008). However, vision-aided navigation systems have some drawbacks: large amount of calculation, field of view constraints, and poor-performance measurements along the camera line-of-sight direction.…”

Analytical Landing Trajectories for Embedded Autonomy

“…To design the guidance and control law, two factors should be taken into consideration to ensure missions success: a low touch down velocity and a vertical attitude on the planetary surface. Many studies on guidance for soft landing have been reported [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. These guidance laws can be divided into two catalogues: 1.)…”