The robot motion planning is generally solved before the robot actually executes the desired motions and in case of motions that must avoid obstacles, this approach may work with static obstacles only. 

If, instead, obstacles are moving, the desired motion must be calculated in real-time, a few milliseconds before its execution.

The problem of real-time motion planning for robots moving in a dynamic environment has been addressed by many researchers and some of the solutions proposed in the literature have been implemented in specific application domains. However, most of these applications are still at an experimental level or confined into a simplified environment. 

In SARAS Project we are developing a software architecture that plans the desired motion of an assistive surgical robot in autonomous mode, avoiding contacts with possibly moving obstacles. In the surgical setup, such moving obstacles can be organs not involved in the current operation or operation phase and other robots not working in autonomous mode: a quite complex environment.

The solution that we are developing will allow the assistive surgical robots, developed within the SARAS project, to move in a dynamic environment, adapting their motions to the current placement of obstacles and, possibly, to their current direction and velocity of motion.

Read more about the problem of the generation of collision-free trajectories for a robotic manipulator, operating in a scenario in which obstacles may be moving at non-negligible velocities in the article: Dynamic Motion Planning for Autonomous Assistive Surgical Robots