ZF presents its flexible Intelligent Rolling Chassis (IRC), a ready-to-launch vehicle platform concept designed to meet essential vehicle design requirements to support future urban mobility solutions. The platform combines an axle-integrated electric drive, an innovative, extremely agile chassis with an advanced steering system and an electronic control unit that coordinates all chassis functions. These intelligently networked mechanical systems have perfectly equipped the IRC for autonomous city driving in the future. At the same time, the completely flat floor between the front and rear axle accommodates almost any vehicle body design. This makes the IRC an ideal and highly flexible platform for developing innovative electric vehicles for either city passenger or goods transport.
“The mobility of the future will continue to be based on mechanical systems, but equipped with intelligent systems that are comprehensively networked,” explains Dr. Stefan Sommer, CEO of ZF Friedrichshafen AG. “In our Intelligent Rolling Chassis, networked and intelligent mechanical systems offer a flexible platform for urban vehicle concepts from well-established and new mobility suppliers.”
Mechanical systems go electric
The Electric Twist Beam (eTB) installed on the IRC rear axle ensures driving with zero local emissions. To achieve this, ZF has combined a twist beam axle with two close-to-the-wheel integrated powerful electric motors each with an output of 40 kW. They are housed together in an aluminum housing, each with a single-speed transmission. The eTB thus forms both an efficient and dynamic drive that brilliantly meets urban mobility and transport needs.
The IRC front axle is based on an innovative dual control arm independent suspension design. It is the main mechanical requirement for increasing — in conjunction with the ZF electro-mechanical steering system — the steering angle up to 75 degrees. As a point of comparison, standard front axles allow for a maximum turning angle of 50 degrees. With this improved steering angle, turning and parking maneuvers will be easier than ever. Greater maneuverability will benefit both passenger and transport vehicles especially in traffic-prone city driving, parking spaces, narrow streets, building sites, traffic jams or loading zones.
Intelligent electronics control unit ensures multiple functions
Another essential system component in the platform is the IRC ECU (electronic control unit) which is the "brain" behind everything that happens in the chassis. It coordinates all of the vehicle’s longitudinal and transverse dynamic functions. It also controls the other ZF systems such as service brakes and power electronics and additionally the battery management. The IRC ECU is additionally equipped with a torque-vectoring function which distributes the driving power between both electric motors, separately when required. This is the only way vehicles built on this platform can drive off from a standstill at an almost 90-degree angle, which is perfect for parking and turning in tight spaces. This electronic control unit comes with all the interfaces required for advanced assistance systems, which also makes ZF’s IRC very attractive as the basic platform for highly automated or autonomous operation of urban transport vehicles.
The IRC has one more trick up its sleeve. In addition to connecting the front and rear axles, its flat floor, the “skateboard,” accommodates the most diverse, simple and needs-based vehicle configurations and interior concepts. These include, for example, the lifestyle-focused two-seater, self-driving taxis with lounge seats facing one another, a reliable vehicle that autonomously goes that last mile to deliver goods in busy urban areas. Such vehicle models are quickly becoming increasingly important for logistics, which is also underscored by the recently published ZF Future Study 2016.