Wabco has introduced two technological enhancements for its electronic braking systems (EBS) for truck and trailer combinations. The two developments are designed to improve the performance of braking systems fitted to extra long trailers and also truck and trailer combinations where two or more trailers are used.
The company’s new controller area network (CAN) repeater is designed for use with extra long trailers, such as specialist types used to transport long loads. Just as EBS systems were designed to speed up braking response times in the air braking systems of large trucks by opening the pneumatic valves electronically (instead of relying on air pressure to do so), so the CAN repeater speeds up response times by amplifying the signal.
The repeater is located near the front of the vehicle, amplifying the signal to the control unit located near the trailer axles at the rear of the vehicle. Wabco could not quantify how much faster the communication would be, telling AEI that this is dependent on a number of factors, including vehicle length, diameter of piping, and the kind of valves.
The CAN router performs a similar function for long trucks consisting of two or more trailers. CAN communication must conform to ISO 11992, which allows for point-to-point communication between one receiver and one sender. According to Wabco, when two or more trailer electronic braking systems are connected to one truck EBS, this single point-to-point communication cannot be ensured because there are a number of senders and receivers that disturb the communication. The CAN router is designed to support and organize the communication between all the connected devices.
So in the case of a truck with two trailers, the router builds up three single point-to-point communication lines. These would be between the truck and the CAN router, between the CAN router and the first trailer EBS, and between the CAN router and the second trailer EBS. By this method, the CAN router coordinates the communication between all devices and ensures that the point-to-point communication is valid and that miscommunication does not appear.
Wabco has also obtained European Union approval for its ESCsmart technology. (See www.sae.org/mags/tbe/news/6683 for more information on this development.)