Editing Humanoid robot (section)

== Planning and control ==
Planning in robots is the process of planning out motions and trajectories for the robot to carry out.<ref name=":14">{{cite journal |last1=Khatib |first1=Oussama |title=Towards integrated robot planning and control |journal=IFAC Proceedings Volumes |date=September 1994 |volume=27 |issue=14 |pages=351–359 |doi=10.1016/S1474-6670(17)47337-X |doi-access=free }}</ref> Control is the actual execution of these planned motions and trajectories.<ref name=":14" /> In humanoid robots, the planning must carry out biped motions, meaning that robots should plan motions similar to a human.<ref name=":15">{{cite book |doi=10.1109/ICMA.2006.257773 |chapter=Planning and Control for THBIP-I Humanoid Robot |title=2006 International Conference on Mechatronics and Automation |date=2006 |last1=Fu |first1=Chenglong |last2=Shuai |first2=Mei |last3=Xu |first3=Kai |last4=Zhao |first4=Jiandong |last5=Wang |first5=Jianmei |last6=Huang |first6=Yuanlin |last7=Chen |first7=Ken |pages=1066–1071 |isbn=1-4244-0465-7 }}</ref> Since one of the main uses of humanoid robots is to interact with humans, it is important for the planning and control mechanisms of humanoid robots to work in a variety of terrain and environments.<ref name=":15" />

The question of walking biped robots stabilization on the surface is of great importance.<ref name=":19">{{cite journal |last1=Bazylev |first1=D.N. |last2=Pyrkin |first2=A.A. |last3=Margun |first3=A.A. |last4=Zimenko |first4=K.A. |last5=Kremlev |first5=A.S. |last6=Ibraev |first6=D.D. |last7=Cech |first7=M. |title=Approaches for stabilizing of biped robots in a standing position on movable support |journal=Scientific and Technical Journal of Information Technologies, Mechanics and Optics |date=15 May 2015 |pages=418–425 |doi=10.17586/2226-1494-2015-15-3-418-425 |doi-access=free }}</ref> Maintenance of the robot's gravity center over the center of bearing area for providing a stable position can be chosen as a goal of control.<ref name=":19" />

To maintain dynamic balance during the [[walk]], a robot needs information about contact force and its current and desired motion.<ref name=":15" /> The solution to this problem relies on a major concept, the [[Zero Moment Point]] (ZMP).<ref name=":15" />

Another characteristic of humanoid robots is that they move, gather information (using sensors) on the "real world", and interact with it.<ref name=":16">{{cite journal |last1=Raković |first1=Mirko |last2=Savić |first2=Srdjan |last3=Santos-Victor |first3=José |last4=Nikolić |first4=Milutin |last5=Borovac |first5=Branislav |title=Human-Inspired Online Path Planning and Biped Walking Realization in Unknown Environment |journal=Frontiers in Neurorobotics |date=4 June 2019 |volume=13 |page=36 |doi=10.3389/fnbot.2019.00036 |pmid=31214011 |pmc=6558152 |doi-access=free }}</ref> They do not stay still like factory manipulators and other robots that work in highly structured environments.<ref name=":16" /> To allow humanoids to move in complex environments, planning and control must focus on self-collision detection, [[path planning]] and [[obstacle avoidance]].<ref name=":16" /><ref>{{cite journal |last1=Du |first1=Guanglong |last2=Long |first2=Shuaiying |last3=Li |first3=Fang |last4=Huang |first4=Xin |title=Active Collision Avoidance for Human-Robot Interaction With UKF, Expert System, and Artificial Potential Field Method |journal=Frontiers in Robotics and AI |date=6 November 2018 |volume=5 |page=125 |doi=10.3389/frobt.2018.00125 |pmid=33501004 |pmc=7805694 |doi-access=free }}</ref>

Humanoid robots do not yet have some features of the human body.<ref name=":17">{{cite book |doi=10.1007/978-94-007-7194-9_7-1 |chapter=A Comparative Study Between Humans and Humanoid Robots |title=Humanoid Robotics: A Reference |date=2018 |last1=Yamane |first1=Katsu |last2=Murai |first2=Akihiko |pages=1–20 |isbn=978-94-007-7194-9 }}</ref> They include structures with variable flexibility, which provide safety (to the robot itself and to the people), and redundancy of movements, i.e. more [[Degrees of freedom (engineering)|degrees of freedom]] and therefore wide task availability.<ref name=":17" /> Although these characteristics are desirable to humanoid robots, they will bring more complexity and new problems to planning and control.<ref>{{Cite web|date=2019-10-02|title=Robots with high degrees of freedom face barriers to adoption|url=https://www.cobottrends.com/robots-with-high-degrees-of-freedom-face-barriers-to-adoption/|access-date=2021-11-04|website=Collaborative Robotics Trends|language=en-US}}</ref> The field of whole-body control deals with these issues and addresses the proper coordination of numerous degrees of freedom, e.g. to realize several control tasks simultaneously while following a given order of priority.<ref>{{cite journal |last1=Khatib |first1=O. |last2=Sentis |first2=L. |last3=Park |first3=J. |last4=Warren |first4=J. |title=Whole-Body Dynamic Behavior and Control of Human-Like Robots |journal=International Journal of Humanoid Robotics |date=March 2004 |volume=1 |issue=1 |pages=29–43 |doi=10.1142/S0219843604000058 }}</ref><ref>{{cite book |doi=10.1007/978-3-319-40557-5 |title=Whole-Body Impedance Control of Wheeled Humanoid Robots |series=Springer Tracts in Advanced Robotics |date=2016 |volume=116 |isbn=978-3-319-40556-8 }}</ref>