During the past three decades, motion planning has emerged as a crucial and
productive research area in robotics. In the mid-1980s, the most advanced
planners were barely able to compute collision-free paths for objects crawl
ing in planar workspaces. Today, planners efficiently deal with robots with
many degrees of freedom in complex environments. Techniques also exist to
generate quasioptimal trajectories, coordinate multiple robots, deal with d
ynamic and kinematic constraints, and handle dynamic environments. This pap
er describes some of these achievements, presents new problems that have re
cently emerged, discusses applications likely to motivate future research,
and finally gives expectations for the coming years. It stresses the fact t
hat nonrobotics applications (e.g., graphic animation, surgical planning, c
omputational biology) are growing in importance and are likely to shape fut
ure motion-planning research more than robotics itself.