Experimental Verification of a Simple Method for Accurate Center of Gravity Determination of Small Satellite Platforms

Abstract

We propose a simple and relatively inexpensive method for determining the center of gravity (CoG) of a small spacecraft. This method, which can be ascribed to the class of suspension techniques, is based on dual-axis inclinometer readings. By performing two consecutive suspensions from two different points, the CoG is determined, ideally, as the intersection between two lines which are uniquely defined by the respective rotations. We performed an experimental campaign to verify the method and assess its accuracy. Thanks to a quantitative error budget, we obtained an error distribution with simulations, which we verified through experimental tests. The retrieved experimental error distribution agrees well with the results predicted through simulations, which in turn lead to a CoG error norm smaller than 2 mm with 95% confidence level.

Research on error separation method of center of gravity measurement system for large-sized solid of revolution

“…During each rotation, the projection of its center of gravity on the X 1 O 1 Y 1 plane of the instrument coordinate system was measured. The X 1 coordinate of the projection point corresponds to the center of gravity of the X axis of the part under test, while the Y 1 coordinate of the projection point relates to the center of gravity of the Y axis and Z axis of the part under When the measured part rotates, the coordinates of the projection point on the X 1 O 1 Y 1 surface exhibits periodic changes [4,17]. By separating the coordinates of the X 1 axis and Y 1 axis of the projection point, the measurement error of the center of gravity of the measured part can be effectively isolated.…”

“…adjustment and other work, and is the premise of accurate control of the aircraft flight attitude. Various testing methods exist, including computer simulation [1], multi-point weighing [2], multi-filar pendulum [3], compound pendulum [4], unbalance moment method, etc [5,6]. The multi-point weighing method uses three or more load cells to support the measuring platform together, and the center of gravity can be measured by the principle of static moment balance based on the relative position of each sensor.…”

General Mass Property Measurement Equipment for Large-Sized Aircraft

“…Mass is a measure of the inertia of an object, and the centroid is the geometric point of equivalent mass distribution. The measurement deviation of the centroid affects the dynamics modeling of the aircraft and the accuracy of the scalar equation of kinematics, which ultimately affects the flight trajectory of the aircraft [ 1 , 2 , 3 , 4 , 5 ]. The MOI is the measurement of the rotational inertia of a rigid body and plays a key role in the attitude control of aircraft in the air [ 6 ].…”

A flexible measurement technique for testing the mass and center of gravity of large-sized objects

“…Given the tremendous workload of simulating a large object and that a perfect analogue of actual conditions can never be realized due to factors such as cable impact and component tolerance, more often than not, the results of simulation are used merely as reference, and experiments have to be conducted to test such results. Among the variety of existing testing methods are multi-point weighing, multi-filar pendulum, and compound pendulum [6][7][8]. There are also some new techniques available for such testing, e.g.…”

“…However, with these methods, mass has to be measured separately. Apart from that, the tests reported in existing literature mainly involve medium and small objects like cars, motors or satellites [2,7,8]. As for the measurement of large-sized objects, many challenges still remain because they are largely measured with unique devices.…”