As satellites become smaller, the ability to maintain stable pointing
decreases as external forces acting on the satellite come into play. At the
same time, reaction wheels used in the attitude determination and control
system (ADCS) introduce high frequency jitter which can disrupt pointing
stability. For space domain awareness (SDA) tasks that track objects tens of
thousands of kilometres away, the pointing accuracy offered by current
nanosats, typically in the range of 10 to 100 arcseconds, is not sufficient. In
this work, we develop a novel payload that utilises a neuromorphic event sensor
(for high frequency and highly accurate relative attitude estimation) paired in
a closed loop with a piezoelectric stage (for active attitude corrections) to
provide highly stable sensor-specific pointing. Event sensors are especially
suited for space applications due to their desirable characteristics of low
power consumption, asynchronous operation, and high dynamic range. We use the
event sensor to first estimate a reference background star field from which
instantaneous relative attitude is estimated at high frequency. The
piezoelectric stage works in a closed control loop with the event sensor to
perform attitude corrections based on the discrepancy between the current and
desired attitude. Results in a controlled setting show that we can achieve a
pointing accuracy in the range of 1-5 arcseconds using our novel payload at an
operating frequency of up to 50Hz using a prototype built from
commercial-off-the-shelf components. Further details can be found at
this https URL

通过使用新颖的载荷，结合神经形态事件传感器和压电阶段，我们可以在高频率和高准确性下对星载传感器进行稳定的定位，实现在纳秒尺度上的指向精度。