Angular momentum (AM) tracking can improve MPC by allowing the humanoid robot to more effectively maintain balance and stability during walking, running, jumping, and other dynamic motions  . However, traditional control approaches often assume a fixed or pre-specified angular momentum trajectory, which can limit the robot’s ability to adapt to changing conditions or disturbances.
The AM dynamics involve coupling between the robot’s upper and lower body, making it challenging to control independently. Moreover, tracking AM is also subject to the limited humanoid robot joint actuators. Thus, it is challenging to accurately estimate and track the AM.
 J. Englsberger and C. Ott, “Integration of vertical com motion and angular momentum in an extended capture point tracking controller for bipedal walking,” in IEEE-RAS Intern. Conf. on Humanoid Robots, 2012, pp. 183–189.
 S. Kuindersma, R. Deits, M. Fallon, A. Valenzuela, H. Dai, F. Permenter, T. Koolen, P. Marion, and R. Tedrake, “Optimization-based locomotion planning, estimation, and control design for the atlas humanoid robot,” Autonomous robots, vol. 40, pp. 429–455, 2016.