Extended factitious force idea vs non-ideal velocity constraints method in control of the SSMP platforms

The work presented in this paper shows the idea of extended factitious force method for control of skid-steering mobile platforms and the approach of non-ideal velocity constraints. The same model for both methods is presented and compared. It is shown that the both methods are different in origin but are a mechanism of overcomming a problem of underactuation on dynamic level. Extended factitious force introduces new virtual inputs to the system while the non-ideal velocity constraints method allows a small disturbance which bends the constraints imposed on the system. The methods are compared in terms of an estimation of slippage where the newly introduced terms are linear combination of the other method.