  Constrained attitude maneuvers have numerous applications in robotics and
aerospace. In our previous work, a general framework to this problem was
proposed with resolution completeness guarantee. However, a smooth reference
trajectory and a low-level safety-critical controller were lacking. In this
work, we propose a novel construction of a $C^2$ continuous reference
trajectory based on B\'ezier curves on $ SO(3) $ that evolves within
predetermined cells and eliminates previous stop-and-go behavior. Moreover, we
propose a novel zeroing control barrier function on $ SO(3) $ that provides a
safety certificate over a set of overlapping cells on $ SO(3) $ while avoiding
nonsmooth analysis. The safety certificate is given as a linear constraint on
the control input and implemented in real-time. A remedy is proposed to handle
the states where the coefficient of the control input in the linear constraint
vanishes. Numerical simulations are given to verify the advantages of the
proposed method.
