The EB+ 4.0 system applies or releases the brakes by responding to electrical signals received from the brake pedal, which responds by using solenoids to modulate air pressure in a closed compressed air system connected to axle-mounted brake actuators.
That design is maintained for service brakes. But unit’s new modular design provides additional features, as well as facilitating hardware and software customisation.
Thanks to a new optional valve bank, extends electronic control for the first time to the parking (spring) brake side of the double-diaphragm brake actuator. Previously, connecting the red Suzie coil between truck and trailer would automatically release the parking brake if the red knob of the park and shunt valve is not activated. Now, the system provides additional control of that process, via the EBS ECU (electronic control unit) and an extra solenoid valve. The EB+ 4.0 supports a 12V and 24V voltage supply of the vehicle, thereby making it suitable for customers in all global markets.
First, this so-called ‘Mobiliser’ feature connects the parking brake release command to other onboard microprocessor- controlled systems for additional security checks – such as the closure of the rear door lock, or the detachment of a charging cable, in the case of an electric fridge assembly. To prevent theft or misuse of the trailer, it could compare the VIN of the tractor it has been hitched to, to a white list of approved tractors, before releasing the brake.
Or, with this system, the tractor might remain locked in place until it is able to reach, via a telecommunications box connected to the data cloud, a remote telematics system. This might compare its transmitted location to the expected position based on its planned itinerary, to make sure it has not been taken outside of its authorised area. Alternatively, the ‘go’ signal might come direct from head office. (Semi-trailers with parking brakes fitted with conditional control do not require continuous power, but they do require an electrical connection from the tractor and to be able to receive a data signal.)
These are just a few examples and by no means exhaustive; such functions must be programmed into the system via a new application programming interface (API).
Haldex is quite flexible when it comes to implementing such modifications. On behalf of the customer, the company can develop customised functionalities or incorporate customer functions into regular software updates, and by the same token, a customer-specific release plan can also be agreed. What makes all of this possible is strict separation between application software and braking software. Previously, any change to braking system software could affect the vehicle’s type approval and might face regulatory review.
Not so with EB+ 4.0, as Haldex has further separated safety-related brake control features from customer-specific software.
That means that it is potentially easier to make changes and maintain the overall safety of the system with EB+ 4.0. Beyond the mobiliser feature, the new connectivity aspect provides real-time, remote access to operational data. One immediate benefit is compliance: trailers fitted with EB+ 4.0 comply with the new European regulation R141 for on- board TPMS.
This regulation requires EBS to transit the tyre pressure and temperature information to the tractor unit.
And access to real-time information from the EBS system can lead to further potential logistics and engineering benefits, once that data is provided available for connection to external fleet management software for further processing and analysis. TPMS can give information about pressure and temperature, and so might indicate tyre wear and pressure if the temperature increases. EBS knows the load profiles, and deceleration levels and ABS events and stability systems, so may give an indication to the system about brake pads and wheel bearings.
Alexander Kraus, Senior Commercial Product Manager, said: “In the truck and trailer world, software features and telematics is all about the cargo, so fleets would like to know everything about the goods they are carrying. However, from a preventive maintenance perspective, information from the system and its capability becomes quite important. It is also useful in autonomous driving. The current system’s capability is substantial for AI to know what the system is capable of, to plan the next braking event. Access to the status of the system is crucial capability for AI for the control unit to understand its next manoeuvre.”
EB+ 4.0 also offers two other system enhancements that improve the safety of trailers in operation, without involving customisable software or optional features.
First, the existing Safe Parking system, which provides extra safety when coupling and uncoupling, has been improved. Safe Parking + will not release the parking brake until the system detects a safe condition: that the air brake system
is fully pressurised, and the driver has depressed the service brakes or the service brake is applied by the trailer control valve of the truck. That means that the air coils have been connected (and in the correct order), and that the driver is back in the cab.
This increases the protection of roll-away incidents compared to the previous Safe Parking system, which would only release the semi-trailer brake when the driver pressed a lever mounted to the side of the vehicle. In addition, it prevents the possibility of roll-away if the combination were parked on a grade and the driver forgot to apply the tractor parking brake, or if it were on a grade and the driver attached the coils in the wrong order. Second, another safety system added is emergency brake override, though it is not in fact new; it was a feature on Haldex EB+ Gen1 and has been reintroduced.
It comes as Standard with most EBS variants, and blocks emergency application of the parking brake when the vehicle is moving (by reading input from the wheel speed sensors). This is perfectly legal. ECE R13 safety regulations stipulate that if the energy supply between truck and trailer is lost, the trailer must apply emergency braking. This could be via the parking brake, as has been the case with previous versions. While this will bring the truck and trailer to an almost immediate halt, during that process the trailer wheels will lock, destroying the trailer tyres and threatening those vehicles travelling near the vehicle.
But the safety regulation also allows emergency actuation via the trailer service brakes. That offers several advantages, the least of which is that braking can be controlled by ABS protection. A greater advantage is that this option facilitates the use of the emergency brake override system. If the emergency brake override detects that the energy supply has been disconnected or lost, but if there is sufficient air pressure in the system to operate the service brakes, it will do two things: trigger a red warning light in the cab, and override immediate actuation of the brakes.
During this time, the driver will be able to use the existing air pressure to operate the service brakes as normal to stop in a controlled manner at the nearest possible opportunity. Such manoeuvres depend on an intact electrical connection between tractor and trailer. Once the truck reaches a lower brake pressure threshold, the emergency braking system applies the spring brake, as the regulations require.
New hardware in EBS+4.0 includes redesigned solenoids that are smaller, more robust but lighter than before. In addition, the system is also lighter, as it is now constructed from engineering-grade polymer. A switch from metal
to engineering plastic for construction of the new valve control unit, plus redesigned solenoids, achieves a weight savings of 35 per cent to 3.9kg, and total embedded CO2 of 30 per cent (to 43.3kg per unit).
Four different versions are available: a basic EBS with two modulators and two wheel-speed sensors with no emergency brake override; a basic EBS with emergency brake override; a premium EBS with two additional electrical interfaces, which can be extended to eight sensors and four modulators; and an additional modulator, which is used to map larger systems. As Standard, EBS+ 4.0 comes in a 2S/2M configuration suitable for fitment to three-axle semi-trailers.
Haldex has signed a long-term agreement with several trailer manufacturers for the supply of EB+ 4.0 for trailers. The system has been in development for seven years.
EB+ 4.0 brings parking brake control into electronic management; a new modular and customisable approach to functions which provide new digital services opportunities; 35 per cent weight saving and 30 per cent reduction in embedded CO2; and additional safety features as standard.