A knowledge of the inertia tensors and centre of gravity locations of rigid bodies and rigid mechanical systems is required in precise control of motion and in many other applications whenever the dynamics of them is significantly determined by these inertia parameters. This paper presents a new method for identifying the inertia tensor and coordinates of the centre of mass of a rigid body or of a rigid mechanical system. The proposed method is based on the work-energy principle and provides high accuracy of identification even on devices with essential dissipation. The tensor and centre of gravity location are defined on a single spherical motion -symmetric precession. The paper gives a survey of existing inertia parameter identification methods, the theoretical fundamentals of the proposed identification method, the hybrid identification device and data processing procedure with error estimation on dissipative systems using proposed and classical methods.

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The paper proposes a new adaptive method for identification of the axial moment of inertia for a two degrees of freedom reaction wheel pendulum with viscous friction in suspension bearings. The pendulum contains a rod, a controlled DC motor and a flywheel attached to the rotor shaft. One end of the rod rotates in hinge bearing. The controlled DC motor with a flywheel is attached to the other end of the rod. The angles of rotation of the rod and of the controlled flywheel are measured by encoders. The proposed adaptive method is based on an energy algorithm with reversible symmetric motions of the pendulum system. The symmetric motions are used to eliminate the influence of dissipative factors on the results of identification. The results of computer modelling and experimental results show high accuracy of the proposed identification method.

The moments of inertia of solids are usually experimentally determined on irregular axial rotations and the inertia tensor of the body at its point -on six axial rotation, or on non-spherical motions. Frictional forces in bearings of the actuator adversely affect the accuracy of parametric identification. The paper proposes a method of parametric identification of the inertia tensor matrix of a rigid body and the coordinates of its centre of mass at a spherical motion of the particular form. The proposed method can be used on devices with essential friction.

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