Making fast informed decisions is vital on the battlefield but being able to act quickly is equally important. Wheeled vehicles have an advantage over tracks when it comes to ride quality, speed, reliability and fuel efficiency.
However, these benefits come at the cost of reduced terrain accessibility. The UK Defence Science and Technology Laboratory (Dstl) and defence prime QinetiQ are working towards choices of stealthy armoured vehicles which are more agile, more mobile, more efficient and easier to deploy beyond 2030.
Dstl technical lead William Suttie tells Global Defence Technology: “There are two things within my research.
“Firstly, what we are looking how would you enable the proof to operate at a high temper – that is moving quickly, making lots of very fast decisions. On the other side, this project is about the mobility side of things.”
Improved operational mobility
The project aims to achieve improved operational mobility and allow faster travel speed while remaining safe.
Suttie explains: “We looked at electric hub-drive that gives a lot of flexibility in terms of suspension design. Then we started working with QinetiQ to see how we can exploit that in a novel solution.”
The result is an 8×8, battery-powered and currently remotely piloted ground vehicle system called Mobility Test Rig (MTR). The completed vehicle would likely need to be hybrid, however, considering the additional weight carried by a ground platform.
All wheels have individual torque, the ability to turn and the hub-drive can extend or reduce the distance between the wheels and alter the height of the suspension.
“We’ve not only got long-travel suspension, but the suspension can rotate, and this gives tremendous advantages for mobility,” Suttie explains.
“The vehicle can go into what we call a flotation stay mode, where the vehicle is moving in a crab-like motion. Each wheel follows a different path, so you don’t get rutted.”
The concept could be used on vehicles in about five years, initially on light infantry vehicles. Some of the MTR technologies may be deployed on uncrewed ground vehicles (UGVs), but the concept is aimed at future platforms up to 40 tons.
Achieving high speeds safely
The MTR concept will allow for speeds of 100km/h, which can be hazardous off-road without adequate precautions. The main challenge the project team faces is how to achieve high speeds safely. Suttie believes the control system is the area on which the team needs to focus the most.
“You’ve already got active suspension and the sensors on the front of the vehicle that is looking at the trailer flaps,” he explains.
“Those sensors could also be used as collision avoidance sensors. And because we’ve got an electric drive, you can control the torque on each wheel that allows for torque vectoring”.
This technology is commonly used in rally cars to maximise steering ability.
“When the MTR is going at high speed, the system will sense that and will lower the suspension height and lower the vehicle’s centre of gravity, so it is less susceptible to roll over,” Suttie says.
The wide array of sensors installed on the system could support autonomous driving. Suttie believes, however, that fully autonomous driving off-road would be difficult to achieve given the lack of road markings and curbs that civil systems can use to navigate. But the MTR could have an autonomous driving mode when conditions allow.
Dstl started experimenting with similar mobility solutions five years ago, but it only started working with QinetiQ in 2019. Suttie says the partners could have chosen a more exotic suspension solution, but MTR provides operational flexibility without being too complex.
“Look at Hyundai’s walking car. It looks very good, but it would never work in a military context. In the military, you want something robust and this [MTR] is a fairly simple double-wishbone suspension which articulates in a clever way,” Suttie adds.
As the next step of the project, the suspension will receive power articulation and the MTR will have a full control system implemented. The current research ends in March and the team is exploring the next stages closely with the British Army.
Suttie says: “Probably in about two years’ time we’ll start building a full-size demonstration rig of about 25 tons.”
He explains that is the weight where all potential risks and challenges can be addressed without going too heavy and compromising cost-efficiency. British soldiers could have hands-on experience with the system in about four years.
MTR’s survivability and protection would mainly rely on signature management instead of heavy armour. Dstl has run several experiments, some of them in a synthetic environment, which opened up new survivability options.
“What we’re finding, is that if you exploit your agility and your low signature, you can detect the enemy without them detecting you and engage them. We see active protection as a sort of pull-back-home, so if things go wrong you’ve got extra protection,” Suttie explains.
The modular hub drive uses 20% less fuel and reduces emissions proportionally. Suttie says using the electric drive is a win-win situation from a capability perspective.
“It reduces your logistic drag, gives you export power, smoother running, a more powerful system and it is good for the environment,” he adds.
“This project is not simply about making wheeled vehicles better, it is actually helping them change the way they operate, to have the ability to quickly be deployed with a stable, reliable platform.”