The estimations of induction machine equivalent circuit parameters are still being widely used in the analysis and in determining the characteristics of the machine. Since the most important part of the machine is the rotor where torque is produced, the calculation of rotor resistance correctly will directly affect all other data. Almost all parameters belonging to the stator side can easily be determined through external measurements. However, due to the formulation of the rotor as a closed box, estimating rotor resistance and the rotor's slot shape by heuristic algorithms, without damaging the rotor physically, and comparing it with its actual value constitutes the first focus of this study. In this regard, rotor resistance and slot parameters are estimated through heuristic algorithms depending on the induction machine design aspects. Secondly, an improved particle swarm optimization is presented and compared with conventional PSO and genetic algorithm.