Te within the local horizontal geographic frame and that in the grid frame is deduced. 2-Hydroxyhexanoic acid Metabolic Enzyme/Protease Flight experiments at mid-latitudes initially proved the effectiveness on the covariance transformation strategy. It’s hard to conduct experiments inside the polar area. A purely mathematical simulation can not accurately reflect genuine aircraft situations [19]. To solve this issue, the authors of [19,20] proposed a virtual polar-region technique primarily based on the t-frame or the G-frame. In this way, the experimental information from middle and low latitude regions can be converted to the polar region. Verification by semi-physical simulations, based on the proposed method by [20], can also be conducted and offers additional convincing outcomes. This paper is organized as follows. Section 2 describes the grid-based strap-down inertial navigation program (SINS), such as the mechanization and dynamic model of the grid SINS. In Section 3, the covariance transformation strategy is presented. Additionally, Section 3 also offers a navigation frame-switching method primarily based around the INS/GNSS integrated navigation process. Section 4 verifies the effectiveness of your proposed approach by way of experimentation and semi-physical simulation. Finally, common conclusions are discussed in Section 5. 2. The Grid SINS 2.1. Grid Frame and Grid SINS Mechanization The definition in the grid reference frame is shown in Figure 1. The grid plane is parallel towards the Greenwich meridian, and its intersection together with the tangent plane in the position with the aircraft is definitely the grid’s north. The angle amongst geographic north and grid north provides the grid angle, and its clockwise direction may be the constructive path. The upAppl. Sci. 2021, 11,Appl. Sci. 2021, 11,three of3 ofnorth gives the grid angle, and its clockwise direction would be the constructive path. The up path of the grid frame will be the same as that on the neighborhood geographic frame and types an path on the grid frame will be the same as that from the regional geographic frame orthogonal right-handed frame using the orientations at grid east and grid north. and forms an orthogonal right-handed frame using the orientations at grid east and grid north.Figure 1. The definition on the grid reference frame. The blue arrows represent the 3 coordinate Figure 1. The the nearby geographic frame. The orange arrowsarrows represent thecoordinate axes of your axes of definition in the grid reference frame. The blue represent the three 3 coordinateframe. the neighborhood geographic frame. The orange arrows represent the three coordinate grid axes of axes with the grid frame.The grid angle is expressed as identified in [9]: The grid angle is expressed as discovered in [9]: sin = sin L sinsin =1sin sin L -cos2 L sin2 cos – cos two Lcos = sin two(1)cos CG The path cosine matrix e= between2the G-frame as well as the Bevantolol GPCR/G Protein e-frame (earth frame) is 1 – cos L sin 2 as found in [9]: G G G Ce = Cn Cn e The path cosine matrix C between the G-frame and also the e-frame (earth frame) (two)ecos1-cos2 L sin(1)G where n [9]: is as identified in refers to the nearby horizontal geographic frame. Cn and Cn are expressed as: e G G n (two) -C e C n C e cos sin = 0 Cn = – sin L cos – sin L sin cos L e n G exactly where n refers towards the nearby horizontalcos L cos frame. sin and C n are expressed as: geographic cos L C e sin L(three)- – sin cos cos sin 0 0 G – sinCn cos sin L sin 0cos L n = – sin cos (four) Ce = L (3) 0 0 1 cosL cos cos L sin sin L The updated equations on the attitude, the velocity, and the position in th.
