The dynamic friction and force ripples are the most important factors affecting the positioning accuracy of gun servo systems;therefore,real-time compensation with a continuous control law is used to account for these effects.

The accurate measurement of torque ripple of PMSM is important for high performance applications of PMSM.

This paper analyzes the armature reaction of the brushless DC servo motor by means of finite element method (FEM),and points out that the armature reaction has great influence on torque ripple.

Park transfer is used for analysis of the torque ripple in a sine wave brushless DC motor using the torque formula for sine wave brushless DC motor in d q coordinates.

Model of the ripple torque of Multiplayer feed forward neural network is constructed and the special amplitude and phase of compensation input can be got from the succesfully trained neural network.

The digital simulation of ripple torque of sine-wave brushless DC(BLDC) motor system is studied by the Pspice software.

This paper introduces several principal methods to minimize the ripple torque of brushless DC motor (BLDCM) system,comparison of these methods is also given.

The wave-induced water particle velocity around a ship under the broaching-to condition is expressed in term of an equivalent yaw rate so that the hydrodynamic derivative for ship manoeuvre motion in calm water can be used for estimation of the wave-induced lifting moment.