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sults of themaximization task are shown in the fol- lowing figures. Almost allmotor torque restrictions are active due to themaximization. As can be seen inFig. 8, the first armmoves at the start in the neg- ative direction. The resultingmotion performs as a swing-upprocedure. M1 M2 M3 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -1 -0.5 0 0.5 1 q˙1 q˙2 q˙3 t in s 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -1 -0.5 0 0.5 1 Figure 8: Normalized motor torques and rotational velocities of thevertical torquemaximization Fx Fy Fz 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -40 -20 0 20 40 60 80 100 Mx Mz t in s 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -10 0 10 20 Figure 9: Joint forces and torques of the vertical torquemaximization 6.Conclusion Arm systems of humanoids are used in different ways, e.g. to counterbalance the torque around the vertical axis. Motion planning in relation to var- ious tasks becomes an important role. Therefore, in this paper different optimization goals regarding armmotionswere analyzed. Cost functionswith re- spect to time optimal control, joint load minimiza- tion and vertical torquemaximization were consid- ered. The dynamic optimization process has been converted into a static optimization process byusing B-splines curves to formulate trajectories. TheNLP were solvedwith theSQPmethod. Acknowledgments This work has been partially supported by the “LCM – K2 Center for Symbiotic Mechatronics” within the framework of the Austrian COMET-K2 program. Additional support is providedby theLinz Institute ofTechnology. References [1] M.Benati, S. Gaglio, P.Morasso, V. Tagliasco, and R. Zaccaria. Anthropomorphic robotics. I. Repre- sentingMechanicalComplexity, pages125–140,180. [2] H. Bremer. ElasticMultibody Dynamics: A Direct RitzApproach. SpringerVerlag,2008. [3] T. Chettibi, H. Lehtihet,M.Haddad, andS.Hanchi. Minimum cost trajectory planning for industrial robots. European Journal of Mechanics - A/Solids, 23(4):703–715,2004. [4] H.Gattringer. Starr-elastischeRobotersysteme: The- orieundAnwendungen. SpringerVerlag,2011. [5] K. Hirai, M. Hirose, Y. Haikawa, and T. Takenaka. The developmentof honda humanoid robot. InPro- ceedings. 1998 IEEE International Conference on Robotics and Automation, volume 2, pages 1321– 1326,1998. [6] J. Mayr. Development and Control of a Modular BipedalWalkingRobot. TraunerVerlag,2016. [7] G. Nelson, A. Saunders, N. Neville, B. Swilling, J. Bondaryk, D. Billings, C. Lee, R. Playter, and M. Raibert. Petman: A humanoid robot for testing chemicalprotectiveclothing. Journalof theRobotics SocietyofJapan, 30(4):372–377,2012. [8] L. Piegl andW. Tiller. TheNURBSBook. Springer Verlag,1997. 63