  The process of massive star formation is tightly connected with the
appearance of molecular outflows, which interact with surrounding interstellar
medium and can be used as a proxy to study the accretion process of material
onto forming massive stars. We aim to characterize the morphology and
kinematics, as well as the driving source, of the molecular outflow from the
massive young stellar object G192.16-3.82, which is associated with the giant
Herbig-Haro flow HH 396/397, spanning over 10 pc. We present new, high spatial
and spectral resolution observations of the complex at near-infrared
wavelengths ($2.0-2.3$ $\mu$m) using the LUCI near-infrared camera and
spectrograph with the Advanced Rayleigh guided Ground layer adaptive Optics
System, ARGOS, at the Large Binocular Telescope. We discover a string of
tightly collimated knots of H$_2$ emission, spanning the full observed field of
$\sim4^\prime$, and determine an excitation temperature of $2600\pm500$ K for
the brightest knot, which is situated close to the driving source. We show that
the kinematics of the knots are consistent with them being ejected from the
central source on timescales of a few times $10^{2-3}$ years. The driving
source (or sources) of the outflow is obscured at near-infrared wavelengths,
possibly due to a thick accretion disk. The distribution of H$_2$ emission in
the region, together with high mass-infall rates reported recently, indicate
G192 has undergone several large accretion bursts in the recent past.
