Mobile robot path planning is one of the most essential problems in robotics. This work proposes a novel PSO-based method for mobile robot local path planning in dynamic unknown environments. Using this method, the robot is able to accelerate or decelerate in order to avoid collision more efficiently. In addition, the proposed method defines a fitness function that incorporates multiple optimality criteria as well as the risk of collision. This work also experimentally showed that the proposed method outperforms a D* Lite baseline and can work in a multi-robot path planning setting. The differences in the behavior of the path planner with different prioritized objectives are observed.