ZF boosts braking safety with OnHand
ZF has explained the workings and benefits 
of its OnHand Electro-Pneumatic Handbrake (EPH) system.
“While already increasingly common in passenger cars, the EPH is becoming an essential feature for commercial vehicles, providing improved safety and extra stability,” said ZF.
“Its secondary braking capabilities also acts as a building block technology towards autonomous driving.
“Supporting the commercial vehicle industry’s advance towards zero accidents, ZF’s OnHand, a state-of-the-art EPH system, replaces the conventional parking brake with an advanced, innovative mechatronic device and an electronic control unit.”
In production at ZF’s Hanover plant since 2022, OnHand features integrated anti-lock braking support and anti-roll supervision with automatic actuation in line with the latest (UN R13) regulatory requirements, providing a broad range of safety functionalities including manual and secondary braking.
In addition to enhancing vehicle safety, it comes as a stand-alone plug-in solution with unique lean design concept, says the firm, and supports electric, as well as conventionally powered, trucks and buses.
“Enabling automatic ‘engage and release’ functionality via an ergonomic dashboard lever, its unique design is based on bi-stable solenoid valve technology,” ZF explained.
“It engages and releases the parking brake automatically, for example when the driver’s door is opened, and then releases the brake when the accelerator is applied.
“Another safety feature is that it acts as an automatic secondary brake which engages the parking brake in the event of a brake failure.
“If the brake pedal is applied, but the primary braking system fails, then OnHand automatically intervenes to provide a vital back-up brake, avoiding a potentially dangerous situation. The driver can still control the braking intensity with the brake pedal.”
In a similar vein, OnHand can also act as a manual secondary brake.
“If for some reason the footbrake cannot be applied, for instance if it is blocked by object which has fallen to the cab’s floor, then the driver can pull the OnHand lever to bring the vehicle to a stop in a controlled way,” said the company.
“OnHand also provides extra support on hill starts. If the hill start aid system times out before the vehicle starts moving forward, then OnHand automatically applies the parking brake to prevent the vehicle from rolling backwards down the hill.
“The system can also provide extra ABS protection for automatic and manual gradual secondary braking in order to avoid a collision or in another emergency braking situation.”
