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50 that have been designed variably as passenger cabins or parcel racks, which can be slid into outer ‘skateboard’ chassis that lock the pods in place on four sides. “I first envisioned this kind of modular vehicle four years ago; since then, a number of automotive OEMs and Tier 1 suppliers have come up with modular designs of their own, with companies like Mercedes lending credibility to the idea,” says Frank Rinderknecht, CEO of Rinspeed. “What we’re aiming for in particular is avoiding the short lifespans that smart mobility is in danger of moving towards. “Computers and smartphones have to be replaced every five years because of hardware advances and resulting software incompatibilities. Automotive vehicles these days last for 20 years, but if they’re regularly updated with flawed software – like so many electronic devices – or some other flaw is found with, say, a Lidar or one of the cameras, then people will lose trust in what OEMs are producing.” However, if the mechanical lifespan of the chassis is reduced to only three to five years, the pods can still be used for far longer (as they can still be installed into a new chassis), lowering the overall cost of ownership. The MetroSnap structure has been designed by Swiss company 4erC and built at another Swiss engineering company, Esoro. As it is an electric vehicle, the battery pack is being designed with close attention to componentry. The skateboard’s energy storage uses a Clean Energy Pack system from Berlin-based Clean Energy Global, a 48 V battery pack with two Panasonic NCR18650 cells for 4 kWh. For thermal management, Kebablend/TC plastics from Barlog Group are used as a medium for conducting heat from the cells out to the outer enclosure. Also, thermal management company Eberspacher has supplied the environmental systems for heating and cooling the passenger pod, and additional heating and refrigeration units for the cargo pod, with accumulators to enable autonomous power supplies for both. Connectors from Harting provide both the power and data links between the pod and skateboard as soon as the two are successfully interlocked. Early versions of the vehicle are expected to be manned, with autonomy to be developed and installed afterwards when the technology and regulations allow. This future autonomy will use AI- supported fleet management software and connectivity apps from ESG Mobility, who will also consult on the ongoing development of the electronics architectures relating to the swappable vehicle components. The MetroSnap has also integrated triple-redundant steering and braking systems. In further preparing the vehicle for autonomy, Rinspeed has integrated the Space Drive drive-by-wire system from Schaeffler Paravan. This combined hardware and software automotive solution can process CAN, FlexRay and LIN bus digital signals as well as analogue signals such as those from joysticks or steering wheels. These are combined in real time with essential vehicle data such as braking signals and speed, before being passed on to servo motors for controlling the accelerator and brake pedals, in addition to steering consistently using logical validity checks. Lidar sensors from Ibeo will be installed for perception and classification of obstacles and people. “Much of the structural and control engineering is now done, so future development work is planned to examine applications such as how the hand-off for parcels and shopping from the vehicle to recipients might work,” Rinderknecht adds. Conclusion With so many UGVs specialising in terms of their mechanical designs and intelligent software, there is growing potential for new generations of componentry and subsystems to be developed to suit their unique operating parameters and safety requirements. Precision-engineered motor parts, new battery technologies, cost-effective Lidar and cyber security products (to name a few) could be in extremely high demand among such manufacturers in the near future. They will need customised designs and performance qualities outside of those which automotive and UAV technologies can provide. April/May 2020 | Unmanned Systems Technology Insight | UGVs The MetroSnap will use different ‘pods’ swapped in and out of the same ‘skateboards’ to switch between transporting people and packages as needed (Courtesy of Rinspeed)