Tokyo, Japan - This is Toyota’s Sora* zero-emissions concept bus, using a development of the Mirai fuel-cell system to transport inner-city passengers while leaving behind nothing but water vapour.
It has two 113kW, 335Nm electric motors and two 114kW fuel-cell stacks, fed by 10 high-pressure hydrogen tanks of 60 litres each, for a total capacity of 600 litres, offering 600 litres of hydrogen capacity at a nominal working pressure of 70MPa.
The system also has a 9kW external power supply, with a capacity of 235kWh, which can be used as an emergency power supply. The bus can be parked at an evacuation site such as a school gym or community centre, and provide enough power to keep the lights on for six hours a night, for five days without refuelling.
Because it has no gearbox, clutch or transmission, there’s no lurching as it pulls away from stops; an acceleration control function keeps the pullaway smooth and even, for the safety and comfort of standing passengers.
Some of the seats also fold up when they’re not in use, rather like the seats in an old-fashioned cinema, for the convenience of parents with prams, and passengers in wheelchairs.
At 10.5 metres long, 2.5 metres wide and 3.4 metres high, with a capacity of 22 seated and 56 standing passengers, it’s a big vehicle, so Toyota has fitted eight high-definition cameras inside and outside to detect pedestrians and bicycles around the bus and warn the driver with sound and images.
The concept bus is also set up for futuristic features that won’t be available on the production model, due for release in 2018, simply because the infrastructure isn’t ready for them.
These include Intelligent Transport System Connect, which will use vehicle-to-vehicle and vehicle-to-infrastructure communication to support safe driving, bus convoying and bus-lane priority at traffic lights.
Automatic arrival control improves passenger access by detecting the guidance line on the road surface and automatically steering and braking to stop the bus within 30 - 60mm of the kerb, and within 100mm in front of or after the signpost.
Toyota plans to introduce these features as and when they become available in the cities where the Sora bus is in use.
*Sora is an acronym for Sky, Ocean, River and Air - the earth's water cycle.