  Swing arms have an irreplaceable role in promoting highly dynamic locomotion
on bipedal robots by a larger angular momentum control space from the viewpoint
of biomechanics. Few bipedal robots utilize swing arms and its redundancy
characteristic of multiple degrees of freedom due to the lack of appropriate
locomotion control strategies to perfectly integrate modeling and control. This
paper presents a kind of control strategy by modeling the bipedal robot as a
flywheel-spring loaded inverted pendulum (F-SLIP) to extract characteristics of
swing arms and using the whole-body controller (WBC) to achieve these
characteristics, and also proposes a evaluation system including three aspects
of agility defined by us, stability and energy consumption for the highly
dynamic locomotion of bipedal robots. We design several sets of simulation
experiments and analyze the effects of swing arms according to the evaluation
system during the jumping motion of Purple (Purple energy rises in the
east)V1.0, a kind of bipedal robot designed to test high explosive locomotion.
Results show that Purple's agility is increased by more than 10 percent,
stabilization time is reduced by a factor of two, and energy consumption is
reduced by more than 20 percent after introducing swing arms.
