Developing a virtual environment in which two trainers can network together and perform close proximity maneuvers such as aerial refueling (AR) missions is a new and complex task. The Air National Guard has worked closely with QuantaDyn Corporation to develop a solution and define standards to make the idea of Distributed Mission Operation (DMO) Aerial Refueling a reality. The solution uses an innovative relative positioning algorithm that maximizes positioning precision and minimizes network saturation. When aircraft trainers are networked together, the inherent latency in the network becomes a major factor. It takes a small amount of time for data to travel between trainers, during which both aircraft are moving at high speed, thus when the data arrives it is always a step behind. In order to compensate for this effect, dead reckoning is used to estimate the remote aircraft's position until new position data is received. While standard dead reckoning works well for most networked simulations, there can be position and orientation anomalies that may never be noticed unless the entities are in close proximity for a long duration. During the development of an AR DMO environment involving a Boom Operator Trainer and a Receiver Aircraft Trainer, a few of these anomalies and issues were encountered. These issues include: 1) a "surging" effect where the remote tanker aircraft would suddenly slow down giving the pilot a sense that their aircraft was surging forward; 2) the intricacies of developing dead reckoning algorithms suitable for relative positioning; and 3) the effects of relative versus absolute data packet time stamping on AR DMO. Several operational issues were also encountered including: 1) how to properly initialize networked trainers 2) how to define prerequisites for trainers to take part in AR DMO and 3) how to handle the uniquely detailed AR training environment across a network. This paper will discuss the obstacles both widely known and newly discovered that were encountered while building this unique network environment, as well as the solutions that were applied to allow for multiple trainers to network together and fly prolonged close proximity missions.
Lessons Learned During the Implementation of Aerial Refueling DMO
1 Views