Electronic accelerator, brake or clutch pedal: these are the advantages

The position of the electronic accelerator varies according to the driver's preference. To put it simply, the driver accelerates. The accelerator pedal sensor is the heart of the electronic accelerator pedal. It passes on the load information to the engine control unit. The diesel engine management system uses this as the main control variable for calculating the basic injection quantity and the necessary fuel system pressure, together with the engine speed at the start of injection.

In Otto engine management systems, the accelerator pedal sensor is also used to detect the position of the gas pedal. Depending on the position, the throttle valve actuator is controlled by the engine control unit and adjusted to the throttle valve opening angle, which is dependent on the engine speed and engine load.

The accelerator pedal sensor can be a contactless inductive sensor, a Hall sensor or a potentiometer. Inductive encoders have an internal evaluation circuit and can transmit both analogue and digital signal voltages. HELLA's inductive position sensors (CIPOS®) are highly accurate, robust and extremely compact. The electronic accelerator pedal is a unit consisting of the pedal itself, the electronics, the distance sensor, the haptic unit and the on-board power supply connector.

Depending on the vehicle, the electronic accelerator pedals can be mounted upright or pendant. The accelerator pedal sensor is a safety-relevant component. For this reason, the position data of the accelerator pedal sensor are constantly checked for plausibility, either by switches (idle and full load switches) that are installed as additional components or by one or more additional potentiometers.

In electronic braking systems, the brake pedal is also decoupled from the actual brakes. Whereas in conventional brake systems, hydraulic brake pressure is built up directly via the brake fluid, brake-by-wire systems do this using an electro-hydraulic unit, for example. The pedal travel sensor and/or pressure sensor converts the brake demand into a signal and forwards it either to the relevant actuators or to a separate pressure generator unit with control valves at the respective brake callipers. This means that the brake booster or the ABS/ESP unit, for example, is no longer required. The pedal feel can be regulated dynamically by hydraulic valves or damping units (simulators). The brake control systems include all components required to perform the classic brake functions as well as functions for ABS, ESP, ASR and other assistance functions.

In electric vehicles, depending on the braking situation, the generator function (regeneration) and the classic pedal brake function complement each other. If the central (electro-hydraulic) unit fails, a direct hydraulic connection is established between the brake pedal and the wheel brakes as a safety backup. Ultimately, the driver's active pulse generator is still the actual brake pedal, whether decoupled or direct.

Based on the decoupled accelerator or brake pedal, the electronic clutch pedal also has no mechanical connection to the clutch. An electric motor or actuator opens or closes it. The motor or actuator's position is defined by the position sensor on the clutch pedal. An intelligent control system can be used to optimise the characteristic curve of the coupling process by manually actuating the clutch pedal. This protects the clutch from unnecessary wear. Furthermore, systems, such as a starting assistant, engage assistant, engine stall protection system or a sailing function to reduce fuel consumption, can be implemented.

X-by-wire applications are impossible without sensor technology. HELLA specialises in a wide variety of sensors that are directly or indirectly responsible for making it possible, especially for accelerator pedal sensors and numerous other position sensors. The in-house CIPOS® technology stands for accuracy and reliability.