  We propose a new specification language and control synthesis technique for
single and multi-robot high-level tasks; these tasks include timing constraints
and reaction to environmental events. Specifically, we define Event-based
Signal Temporal Logic (STL) and use it to encode tasks that are reactive to
uncontrolled environment events. Our control synthesis approach to Event-based
STL tasks combines automata and control barrier functions to produce robot
behaviors that satisfy the specification when possible. Our method
automatically provides feedback to the user if an Event-based STL task can not
be achieved. We demonstrate the effectiveness of the framework through
simulations and physical demonstrations of multi-robot tasks.
