How Electrification and Autonomy Can Unlock the Potential of Unmanned Ground Vehicles
Electrification and autonomous technologies open a whole new world of possibilities for the defense sector. While there are certainly barriers and challenges to integrating these technologies and making them commonplace in the near term, there is also huge potential to revolutionize the state of warfare and defense, especially when considering unmanned ground vehicle platforms. At large, an electric and autonomous future in the defense sector will greatly improve the efficiency and effectiveness of military operations, while also substantially reducing the environmental footprint, fully burdened cost of fuel and risk to human life. Likewise, purely electric propulsion systems do not emit any exhaust gases and are much quieter than conventional counterparts, which is an asset for stealth efforts.
Even though these vehicles may not be a reality for quite some time given the need for significant technology and infrastructure advancements, engineers should be diving headfirst into the design possibilities that this sort of transformation unlocks. To fully maximize the benefits that autonomy and electrification can bring, a completely new vehicle architecture is required, making room to re-envision what these vehicles could look like, what technology can be integrated and how much more power can be squeezed from having more design freedom.
For instance, when moving to a fully unmanned platform with no personnel on board and fewer personnel put in harm’s way for missions like fuel convoys, the paradigm between a vehicle’s lethality, mobility and survivability is shifted. And, since autonomy and electrification complement each other, turning toward autonomy is the perfect time to also optimize these defense vehicles for electrification, too.
If personnel are removed from the equation in these unmanned ground vehicles thanks to autonomous technology, then much of the mission risk is omitted. Today, we are already seeing a taste of what the future holds through manned/unmanned teaming in defense, such as with the U.S. Army’s Optionally Manned Fighting Vehicle (OMFV) program.
In this case, a crewed command vehicles takes the lead on a mission with a series of unmanned vehicles following behind. The unmanned vehicles are then leveraged in more vulnerable locations, keeping crews further from harm’s way. Plus, things that have traditionally been essential like seats, windows, manual steering controls, air vents, crew support systems and even doors are no longer needed. By removing the need for the conventional vehicle cab and crew support systems, engineering teams have plenty more space to reimagine the future of combat vehicles. Electrification will also bring unique opportunities to engineering teams, such as the chance to introduce more powerful, next-generation surveillance systems and weapons that would require higher voltages to power and larger batteries to protect for silent watch operations.
Additionally, because the vehicle’s survivability becomes less critical without a crew on board, the amount of armor needed to protect the vehicle from attack can be greatly reduced. The reduction in armor alleviates weight constraints making way for further creative integration of electrified sub systems and battery packs. Plus, thermal management systems can be reconfigured and simplified in the absence of layers of armor, which traditionally offers barriers to vehicle cooling.
Given all these factors to now consider, the engineering of defense platforms has rapidly evolved over the last five years, as an avalanche of new technologies, requirements and potential threats have combined against the backdrop of ongoing government research and development and vehicle acquisition. While there are significant challenges to realizing fully autonomous or fully electric defense vehicles in the long term, the near term offers no shortage of challenges to overcome in considering how vehicles, given their long service life, are engineered to be modular and upgradeable in readiness for the technology of tomorrow.
The overlap this causes between manned-manual, manned-autonomous and unmanned operational modes calls for a sharp focus on failure mechanisms and mitigation strategies when thinking about systems like steer-by-wire and brake-by-wire. Suddenly cyber security and the risk of a vehicle being “hacked,” becomes a very serious consideration when these vehicles may also be operated with a crew in the short term.
A Whole System Approach
This type of technology overhaul isn’t a fit for all defense vehicles, so the best first step when approaching the future of unmanned ground vehicle systems is understanding applicable use cases for specific vehicle platforms, along with weighing associated risks and benefits from the get-go. When possible, taking a whole system approach and reconstructing the propulsion system and vehicle architecture, has the potential to deliver exponential gains. To make the leap, there are several key things to keep in mind, all under the umbrella of a system-level approach.
First, and most importantly, a simulation-led method is the best option to minimize risk and investment while ensuring optimal safety and performance. Evaluating the complete system integration needs using this approach allows for an understanding of the system’s reaction to different duty cycles, use cases, operable conditions and real-world deployment opportunities (which are not easy in tough environments like those encountered in defense). Simulating the capabilities of the propulsion system is exceptionally important. Co-simulating various subsystems and undertaking optimization in this virtual, controlled environment allows for a resulting vehicle that is more robust from a security standpoint and one that optimizes desired attributes – all without incurring the high costs associated with physically adapting new technologies before proving them out.
Thermal modeling and simulation early in vehicle architecture development is also essential to understanding and mitigating failure modes related to electrified systems. Properly developing thermal management systems that can combat the harsh environmental conditions of military routes and thermal challenges presented by the necessity for armor is tremendously important to ensuring durability. Many defense applications would require a 25 percent increase in temperature coverage from commonly available power electronics modules.
Going hand-in-hand with simulation and the use of digital twins is the ability to produce prototypes quickly. Considering that some of the traditional ground platform constraints are removed in unmanned autonomous platforms, the expectation and market demand will be to bring these unmanned platforms to life far more rapidly. This means agile development and delivering a first-time capable prototype. A more traditional approach of build, fail, learn, develop and repeat is far more time consuming, investment intensive, and potentially wasteful when considering the resources expended to build prototypes that may never see service or offer learning beyond what a digital twin can provide.
Developing these digital twins earlier and more efficiently, can help save months of time and tens of thousands of dollars, while ensuring a more robust and reliable concept before the system ever touches a dyno test cell. A good example of this approach in system electrification terms is Drive System Design’s (DSD) approach to motor control development and power electronics integration. Using a phased approach to progressively build confidence in the system and eradicate integration and software issues, errors are predicted and solved prior to, or in parallel with, dyno or test cell work. As a result, the timeline for prototype development and refinement is truncated, enabling OEMs and suppliers to be far more capable at the point of prototype deployment.
In terms of an autonomous vehicle, expertise in control development is essential. For instance, autonomous logic and operation are enabled by sensors and processing tools which plot a path that understands the obstacles and ground conditions like a human operator can. Combined with a hybrid supervisory control system that understands what combination of electric power, the vehicle gets the best energy usage for a given mission profile or set of conditions.
Given the unmanned, software-heavy nature of these autonomous platforms, it is far more possible to treat them as a readily upgradeable platform, provided the hardware is future-proofed. When considering a traditional military vehicle, if crews are put in harm’s way, then the system would need to be subjected to a more rigorous, time-consuming validation plan. Developing unmanned ground vehicles gives a little more tolerance to acting in an agile developmental way because these sorts of platforms can be deployed earlier and more readily upgraded as real word data and feedback becomes available.
Likewise, with an increase in demand for higher voltages and power levels for weapon systems, communications equipment, protection and more, it is important that power electronics, like DC/DC converters, can perform under extreme conditions. Having power electronics that are flexible in both hardware and control and adaptable to a range of batteries or commercial off-the-shelf motors is important to not just deliver basic functionality but to introduce more functionality and upgradeability where possible. Overall, taking a system level approach, and combining autonomous platforms with electrification at the point of vehicle conception, acknowledging the shift in paradigm between mobility, lethality and survivability can be a very powerful way to unlock increased innovation and speed of deployment.
This article was written by Ben Chiswick, Director of Engineering Business Development for Drive System Design, Inc. For more information, go here .