1 possibility is to check if your robots published a qos metric "QOS_CPU_USAGE" the last hour:
---
select a.robot, a.origin, MAX(b.sampletime) as last_sampletime
from CM_NIMBUS_ROBOT a
inner join V_QOS_CPU_USAGE b
on a.robot = b.robot
group by a.origin, a.robot
having MAX(b.sampletime) <= DATEADD(hh, -1, getdate())
order by last_sampletime
---
Note: this example assumes that you have the sql_views script executed to create the qos views