Generating Continuous Motion and Force Plans in Real-Time for Legged Mobile Manipulation

Parker Ewen, Jean Pierre Sleiman, Yuxin Chen, Wei-Chun Lu, Marco Hutter, Ram Vasudevan

Abstract:

Manipulators can be added to legged robots,
allowing them to interact with and change their environ-
ment. Legged mobile manipulation planners must consider
how contact forces generated by these manipulators affect the
system. Current planning strategies either treat these forces as
immutable during planning or are unable to optimize over these
contact forces while operating in real-time. This paper presents
the Stability and Task Oriented Receding-Horizon Motion
and Manipulation Autonomous Planner (STORMMAP) that is
able to generate continuous plans for the robot’s motion and
manipulation force trajectories that ensure dynamic feasibility
and stability of the platform, and incentivizes accomplishing
manipulation and motion tasks specified by a user. A variety
of simulated experiments on a quadruped with a manipulator
mounted to its torso demonstrate the versatility of STOR-
MMAP. In contrast to existing state of the art methods, the
approach described in this paper generates continuous plans
in under ten milliseconds, an order of magnitude faster than
previous strategies.