  This paper presents a control strategy based on time-varying fixed-time
convergent higher order control barrier functions for a class of
leader-follower multi-agent systems under signal temporal logic (STL) tasks.
Each agent is assigned a local STL task which may be dependent on the behavior
of agents involved in other tasks. In each local task, one agent called the
leader has knowledge on the associated tasks and controls the performance of
the subgroup involved agents. Our approach finds a robust solution to guarantee
the fixed-time satisfaction of STL tasks in a least violating way and
independent of the agents' initial conditions. In particular, the robust
performance of the task satisfaction is based on the knowledge of the leader
from the followers and can be adjusted in a user-specified way.
