  Industries such as flexible manufacturing and home care will be transformed
by the presence of robotic assistants. Assurance of safety and functional
soundness for these robotic systems will require rigorous verification and
validation. We propose testing in simulation using Coverage-Driven Verification
(CDV) to guide the testing process in an automatic and systematic way. We use a
two-tiered test generation approach, where abstract test sequences are computed
first and then concretized (e.g., data and variables are instantiated), to
reduce the complexity of the test generation problem. To demonstrate the
effectiveness of our approach, we developed a testbench for robotic code,
running in ROS-Gazebo, that implements an object handover as part of a
human-robot interaction (HRI) task. Tests are generated to stimulate the
robot's code in a realistic manner, through stimulating the human, environment,
sensors, and actuators in simulation. We compare the merits of unconstrained,
constrained and model-based test generation in achieving thorough exploration
of the code under test, and interesting combinations of human-robot
interactions. Our results show that CDV combined with systematic test
generation achieves a very high degree of automation in simulation-based
verification of control code for robots in HRI.
