The Covariant form of four-dimensional torque is studied, the expression of three-dimensional torque that meets relativistic demand is given, with the use of it, Some paradoxs of the torque are explained more satisfactorily.

Mechanism and suppression of extraneous torque of motor driver load simulator;

By analyzing the mechanism of production of the extraneous torque,the extraneous torque compensation and adjustment are made.

The connect rigidity is analyzed which influences the performance of whole simulator, including stability、machine resonance and extraneous torque.

After the disturbance torque is compensated according to the invariance theory,the system can still not meet the requirement.

The analysis of simulation result show that some rules how to select impor- tance parameter should be complied with and the controller has excellent performance and a satisfying ability to decrease the disturbance torque.

According to characteristic of synchro-compensation eliminating disturbance torque for electro-hydraulic loading simulator, referring to the method of model reference adaptive control system, this paper takes steering as referring model, synchro-motor as controlled system to improve the precision of synchro-compensation and eliminate disturbance torque at most.