While technology provides very significant advances in reducing fuel consumption and with it the associated benefits of lower exhaust emissions, driver training can also help with savings.
The problem with that solution, however, is achieving consistency. Technology can give some support in providing indicators for upward gearshifts and instant fuel consumption readouts, but in high-workload conditions in city driving and on busy motorways, these may not be sufficient attention-getters. There are also basic mechanical driver aids including the need for increased accelerator pressure over the last few degrees of movement.
Now, Continental has come up with a solution that allies the thinking behind the latter application but overlays it with subtle use of technology to create a driver-alert system. It is called the AFFP (Accelerator Force Feedback Pedal); the company is making a “world first” claim for the system, believing it is the only mass-produced active accelerator pedal. It creates a gentle pulse.
“Ultimately, it is the driver who determines whether the vehicle’s full technological potential is actually realized. The AFFP uses haptic feedback signals—such as a discreet double 'pulsating' interval or a counterforce in the pedal—to assist the driver,” said Dr. Peter Laier, head of the Chassis Components Business Unit, Continental Chassis and Safety Division.
He explained that trials had shown that drivers were far more responsive to such signals than to warning lights or audible alerts: “By signaling the optimal gearshift point, this HMI (human-machine interface) can lead to fuel savings of up to 7% depending on the type of vehicle.”
A study carried out by Continental and Munich Technical University demonstrated that the AFFP system provided an intuitive, easily understood link with the driver that could be acted on without adding to stress levels. A car with manual gearbox showed that increased counterforce could prompt the driver to ease off the accelerator while a distinct vibration could warn of hazards, including driving too close to the vehicle ahead and, if linked to GPS and navigation data, could provide an early alert of traffic delays or out-of-sight obstacles and traffic controls.
Continental’s specialists also worked with the Institute for Product Development, University of Karlsruhe, which examined the effect of AFFP on a car with automatic transmission.
Driver preference for the type of signal transmitted can be selected using a system memory and recalled via the ignition key. The AFFP technology can be applied to both floor-mounted and suspended accelerator pedals, making it suitable for private and commercial vehicles.
Laier added that the AFFP also offers advantages for hybrid and electric vehicles. In a hybrid, it could give feedback to the driver warning that an approaching pedal position would activate the internal-combustion engine. In electric vehicles, it could indicate how the driver’s vehicle operating profile was adversely affecting battery range.
The AFFP incorporates an electric motor linked to the accelerator pedal. The pedal’s active and passive functions are designed to ensure that the active function cannot counteract or negate the effect of the passive pedal’s return springs, so the actuator cannot cause the vehicle to accelerate, and the required passive pedal return force is maintained at all times.