Hyundai made waves in 2019 with its CES showing of the Elevate concept—an “Ultimate Mobility Vehicle” that featured motorized wheels attached to five-jointed “legs” that enabled it to walk and climb, as well as drive. The best-known walking vehicles in our collective consciousness are those wielded by the evil Empire in the Star Wars movies, so think of this one as a much smaller, nimbler, more agile, friendlier version of an All-Terrain Armored Transport “Walker”—but the “feet” are swapped for electrically powered wheels. Hyundai has continued working on the Elevate concept and recently gave us a progress report.

The Elevate UMV (pictured above) was born in Hyundai’s Center for Robotic-Augmented Design in Living Experiences. CRADLE has since handed the project off to Hyundai Motor Group’s New Horizons Studio, which has pursued the UMV project in collaboration with engineering software developers Autodesk and with Sundberg-Ferar, a suburban Detroit-based product design/innovation studio. In developing the second generation of the Elevate UMV, Hyundai New Horizons has bestowed a new name on the concept: TIGER, which stands for Transforming Intelligent Ground Excursion Robot (below).

TIGER employs four identical robotic legs featuring five degrees of freedom and electrically driven wheels that serve as “feet” just as the Elevate UMV did. For simplicity, the team still envisions utilizing a common actuator at all of the joints across all of the legs, and they’ve made the design symmetrical about its length and width. Its chassis can accommodate different modular bodies, and it can travel freely in any direction, with no defined front or back.

The primary difference between the vehicles is that Elevate was conceived to accommodate passengers and TIGER is not. Eliminating the need to provide occupant protection greatly simplifies the engineering task, but the mobility challenges are essentially the same: maximize payload by optimizing component strength while reducing mass to the bare minimum. Autodesk’s contribution is the company’s Fusion 360 iterative design software that has resulted in the feathery leg segments, which are (at least for now) designed for additive manufacturing (3D printing). Sundberg-Ferar helped to optimize the efficiency of wheeled motion with the robotic articulation of a quadruped in order to ensure TIGER can go anywhere equipment or supplies are needed.

When Elevate was presented as a passenger-carrying vehicle roughly the size of a Wrangler, a 63-kWh battery was expected to be necessary to climb up and back down the Rubicon Trail. The TIGER team won’t be ready to forecast required battery sizes until it identifies specific customers and duty cycles. The team does anticipate being able to regenerate energy from the leg actuators as they resist gravity while climbing down a hill. And if the vehicle is expected to operate for extended periods in extremely remote areas where drone-supply or other battery-recharging methods are impractical, the team anticipates adapting an extremely compact, purpose-built range-extending combustion engine—possibly a power-dense rotary design like LiquidPiston’s “inside-out Wankel. “

This cargo bot will obviously be remotely controlled, relying on a full suite of autonomy sensors as well as onboard artificial intelligence. It must also be capable of being controlled manually, either by remote control, or in the case of the future passenger-carrying Elevate model, from onboard. How do you steer/command a vehicle with 24 degrees of freedom, each with its own motor/actuator? John Suh, VP and founding director of New Horizons Studio, says his team is striving to make it as simple and intuitive as possible. “How many degrees of freedom does a horse have? And you control it with a rope.”

The TIGER X-1 (for experimental, first-gen) is still about the size of a carry-on suitcase (roughly 22 x 14 x 7 inches, measured “crouching”), or about 20 percent of the anticipated size of a functional TIGER. But then, “actual” size will depend on the customer and intended duty cycle. That duty cycle will determine many factors. The payload requirement will determine the body configuration, overall mass, and hence the size and strength of the leg actuator required to provide reliable mobility. And those expectations could even conceivably drive a reduction from five to three actuators per leg.

To aid in its mission to carry stuff over the toughest, most remote terrain either during disaster recovery or in support of mobile scientific exploration New Horizons envisions TIGER being deployed in conjunction with unmanned aerial vehicles (UAVs) that can not only deliver TIGER to the accessible edge of an inaccessible location, but also to recharge it and potentially provide directional commands from above, when needed.

With nobody onboard to whine about ride quality (or to change a flat), there’s no need for pneumatic tires. Additive manufacturing allows for custom-tailored tire treads and compounds suited for the anticipated terrain.

Hyundai New Horizons has yet to engage directly with any prospective customers, but the team envisions this being an invaluable tool for missions such as search/rescue, scientific research, and military scouting and recovery. There’s even CGI imagery of it roving the lunar surface. The next couple of years will be spent sorting out the core technical details, followed by a year or two of production development. The team is targeting 2024 to have “Beta” project samples in the hands of potential customers, with the cargo-carrying version achieving production well ahead of the Elevate passenger version shortly thereafter.