WVU Robotics

West Virginia University Robotics Team is student organization made up of graduate and undergraduate students who participate in competitions and robotics clinics.

Connectivity for a NASA Competition

The design and fabrication of a sample collection rover for the NASA Rasc-Al Robo-ops competition hosted at the NASA Johnson Space Center’s Rock Yard.

Before acquiring the Max HD2 Mini Pepwave system, they were using a pair of Cradlepoint cellular modem/router combos that were bridged over a Wi-Fi link to provide a robust and redundant solution to our networking problems. They positioned one of the Cradlepoint routers at a stationary base station and affixed the other to the rover. This solution worked well when the rover was in line of sight to the base station, but when the rover lost the signal from the base station, the rover was sluggish due to the decreased bandwidth and increased latency.

Success Factors

Lightweight

The competition order is determined by the weight of the rover; a lighter rover has a more favorable position in the lineup. As such, weight is at a premium, which led them to choose the Max HD2 Mini since it was light, rugged, and included a GPS, reducing their need for an extra component.

Rugged

This competition is held in a rugged environment meant to simulate the Martian surface. The components selected needed to be rugged, able to resist dust and moisture. The Max HD2 Mini fit the bill due to its rugged metal case.

Technologies

• Max HD2 Mini 4G LTE
• Balance 210

Lightweight, Robust Connectivity

WVU used the Max HD2 Mini 4G LTE Bandwidth Bonding Router on the rover and a Balance 210 Dual-Wan Router in mission control. The inclusion of the Balance 210 router in their networking solution allowed them to take advantage of the SpeedFusion Bonding. This allowed them to unplug one of the WAN connections, simulating a network fault, from the router and still have control over the rover. This gave them the best balance of speed and reliability.

Installation

The WVU Robotics Team ordered their Pepwave router three months in advance of the completion to allow time to mount and integrate it into the rover. They 3d printed a base to affix the Pepwave router allowing the antennas maximum clearance. Their Balance 210 router took advantage of SpeedFusion Bandwidth Bonding. Once the router was installed, they configured the two routers following the online guides and were able to successfully run speed tests using the PepVPN test and analyzer.

Results

The deployment of Peplink products allowed them to communicate with the rover as if they were on a local network, allowing them easier development of network related features for their rover.

Using the PepVPN Test tool, they tested a single AT&T connection and recorded an average speed of .7 Mbps. When they tested the combined AT&T and Verizon connections, they recorded an average speed of 1.13 Mbps, a 61% increase in bandwidth. When using external network tests, their average speeds were 27.3 Mbps down and 11.1 Mbps up.

The lightweight nature of the Max HD2 Mini allowed them to use it in a weight critical situation. The SpeedFusion Bandwidth Bonding allowed them to operate the rover without worrying about network failures.

“Our previous networking solution wasn’t reliable enough to guarantee mission success. We needed a reliable solution that could handle the loss of one of the cellular connections and still function reliably. “