For a robotic reconnaissance or survey system, one of the biggest real-world navigational challenges to overcome can be geographical obstacles. Even for humans, terrains such as rivers (or other “wet gaps” such as canals and streams) often necessitate slow crossings due to the terrain. Military troops specifically often find themselves navigating in unknown terrain where speed and safety of travel are paramount. Manual surveying, which is both time-consuming and tedious when physically operating survey equipment, is frequently required to determine the proper location to cross such terrain. However, military crossings are often slow and require a large number of vehicles concentrated in a small area as they wait, leaving them vulnerable to enemy attack.
Supporting Troops in Wet Gap Crossings
The Map the Gap: Phase 2 Defence and Security Accelerator (DASA) competition was created to support robotic reconnaissance or survey system solution for surveying wet gap sites. Solutions would have to:
- Deploy and travel to potential crossing places found along a river (bank length larger than 1km);
- Measure the features of the crossing site gap;
- Increase the speed at which the crossing decision can be made.
This scenario was then divided into six basic problems in order to assess the functionality and effectiveness of a suggested solution.
- All physical gap measurements of a prospective crossing point must be collected (i.e. water flow rate, gap width between banks, full river bed profile, etc.)
- Solutions must reduce the burden on the operator
- Obfuscation of solution intent (i.e. low electro-magnetic signature or inability to pinpoint objective bridging location)
- Data must be presented in a user-friendly format
- The solution must offer information on the access zone (for example, ground trafficability, trees/foliage, etc.)
- Solutions must be able to collect data under a variety of environmental circumstances
- Rather than depending on pre-identified sites, the technology detects prospective sites inside the area of operations
Ultrabeam Joins the Competition
Ultrabeam Hydrographic is a UK based high-resolution marine survey specialist that offers hydrographic and geophysical survey services. Ultrabeam creates customized unmanned survey vehicles in order to conduct high-definition surveys of maritime assets above and below water using a combination of sonar and laser sensors. As a result, Ultrabeam was an excellent choice for developing a solution for the Map the Gap Challenge.
Project Axolotl is Ultrabeam’s effort to develop an unmanned solution for assessing water crossings in hazardous territory utilizing Warthog UGV. The use of an unmanned vehicle would eliminate the human element from a potentially hazardous reconnaissance study of a body of water or river. The unmanned remotely operated solution would also substantially improve environmental knowledge by employing highly detailed measuring sensors. Furthermore, after the competition of Axolotl, Ultrabeam intends to employ the vehicle for their main work, such as surveying bridges and rivers, as other industrial vehicles are simply incapable of going where their equipment requires for data collection.
However, one of the most difficult aspects of executing Project Axolotl was the short turnaround time. The Ultrabeam team had fewer than 6 months to create a complicated vehicle capable of meeting all of the Map the Gap challenges.
Warthog UGV let them employ a previously built base chassis and driving system, allowing them to focus on the water capabilities and sensor technology. A more time-consuming option would have been to modify an existing vehicle or build a solution from the ground up. However, the team was not willing to wait out the longer development time or accept the increased chance of failure from converting older vehicles.
“Warthog UGV’s relatively compact design allowed us to tweak and increase our vehicle’s in-water performance. Simply put, the robot had the perfect size and capability for our needs. There was nothing else available on the market that could deliver this.”
– Project Lead Gabriel Walton, Ultrabeam Hydrographic
Creating a Complex, Effective Solution
Warthog UGV was outfitted with Ultrabeam’s autopilot system and renamed the Axolotl as per the project name. This was combined with the 3D LiDAR, underwater 3D sonar, water velocity current sensors, a ground penetrometer, an artificial intelligence obstacle avoidance system, and a high-precision inertial navigation system. Axolotl was additionally outfitted with actuated bow and stern parts to keep its off-road capability while also improving its in-water capabilities. The bow, stern, and gantry built as a single modular assembly that could be removed in 15 minutes and replaced with a standard UGV. The bow was created to shield the multibeam sonar and ADCP from collisions with slopes, stones, or other debris. The stern was meant to provide some protection for the propellers in the event of an accident with the earth or other objects.
In addition, the team designed a vehicle-agnostic survey pod to store all of the necessary sensors and electronics to allow lidar data collection from any vehicle without calibration and with minimal installation. The following components were included in this survey pod:
- High specification acquisition and processing PC
- Advanced Navigation Spatial FOG fibre optic gryo-based INS system aided by twin antenna RTK GPS
- 1 x Ouster OS1-128 lidar for survey data (pitched forward 30 degrees)
- 1 x Ouster OS1-128 lidar mounted horizontally for 3D navigation and AI aiding
Other components necessary for Project Axolotl included:
- 5GHz Ubiquiti Rocket M5 wifi units (main telemetry and 3D data delivery system)
- Skydroid H16 Pro Hand Controller (backup control of the vehicle using standard RC control)
- Norbit WBMS multibeam sonar (3D underwater mapping)
- Nortek Signature 1000 ADCP (river current measurements)
- Wight Ocean ePenetrometer (ground bearing measurements)
When in use, a projected route is programmed into the vehicle, along with waypoints to specified sites. The vehicle adapts the recommended route utilizing AI obstacle avoidance to follow the path. It laser scans everything it comes across, creating a high-definition 3D representation. As the vehicle approaches any body of water, the bow and stern sections deploy, transforming in into a highly capable in-water vehicle. The vehicle next enters the water and uses the 3D sonar and laser imaging above water to map the water in great detail. The river current speed is measured by the water current sensor across the entire river profile. The ground penetrometer is used to determine the capacity of the ground. All survey sensor data is visualized in real-time and recorded using a modified version of QPS QINSY software. The data is sent back to the ground station, resulting in a complete 3D model. The user can then digitally explore the river’s entry and departure points, as well as other aspects like bank strength and river currents.
Axolotl Hits the Mark
Ultrabeam’s Project Axolotl was a complete success, completing the Map the Gap challenge with a proven amphibious vehicle. The vehicle is now in use and has been modified to meet Ultrabeam’s hydrographic survey needs. Ultrabeam will continue to work on Project Axolotl, adding improvements such as a stern section redesign that considerably increases ground clearance for steeper slope water entry.
Project Axolotl’s team members included Gabriel Walton (Project Lead), Nick Brickland (Electrical Engineer), Kian Hocking (Software Developer), and Georg Finch (Mechanical Engineer).
To learn more about Ultrabeam Hydrographic, visit their website here.
To learn more about Warthog UGV, visit our website here.