A novel vector-moving ant colony optimization (VMACO) is proposed to identify two load parameters: inertia
and load torque simultaneously, which affect the performance of velocity control for AC asynchronous motor. Ant
moving is decomposed into X and Y directions, X for inertia, Y for load torque. Every point consists of possible
estimations. Based on minimum variance principle, the pheromone model is established, characterized by that the
closer the distance between the ant position and the virtual position determined by the actual values of inertia and
load torque is, the more pheromone can be obtained. The position where ant colony gathers contains the optimal
estimated results. Simulations and experimental results verify the algorithm.