From Metroflexx to the new Regioflexx
When it comes to brakes, reliability and performance are top priority. Train operators need to know their systems are safe and that they work well – even in degraded conditions. However, if they are to run their networks efficiently, operators also need their braking systems to be competitive in terms of their maintainability and cost-effectiveness, as well as the extra features they provide to get trains ready for the future. With Metroflexx, Wabtec has established a best-in-class reputation for providing all these benefits to metro operators. Our new Regioflexx system now sets the bar even higher with a next-generation offer for suburban, intercity, regional and high-speed trains.
Metroflexx: the Industry Reference
In 2020, we took a tremendous step forward by obtaining certification to safety standards by TÜV SÜD for our Metroflexx solution. When we began developing Metroflexx, we were looking for new ways to improve performance, reliability, maintainability, train integration, predictive maintenance and diagnostic capability, overall competitiveness, and readiness for the future. We adopted the following approach:
- Wherever possible, we replaced pneumatic components with equivalent software modules at the same safety level, up to SIL 4.
- We redesigned all remaining components, using different materials to boost reliability, performance, and lifespan.
- We developed a new generation of adaptive algorithms to enhance control performance and components' lifespan.
This work resulted in a brake control solution with several advantages:
- It is highly integrated into a Line Replaceable Unit;
- It can be interfaced in traditional wired mode or fully networked;
- It includes "per axle" brake control system capacity;
- It comes with a standard hardware platform and modular software, both safety standard compliant (certified up to SIL 4).
Metroflexx is the reference in brake control. It is now our standard offer for metro lines and is already in service in different parts of the world.
Taking our Offer Further
Following on from this success, we are now extending our suite of solutions for main line trains with Regioflexx – our solution for the next generation of suburban, intercity, regional, high-speed, and very-high-speed trains.
As you would expect from a modern integrated brake control system, Regioflexx features service brake, emergency brake, and wheel slide protection; communication with TCMS and propulsion; and diagnostic functions. Going well beyond these features, Regioflexx offers even more thanks to its specific architecture. It is based on two independent pneumatic channels allowing full per-axle control, and a dual independent electronic architecture, one SIL 2-based that performs the usual brake functions, and one SIL 4 that performs different redundancy and monitoring functions.
Rethinking Architecture to Boost Performance
Regioflexx’s unique and patented architecture offers numerous impressive benefits – especially in terms of performance. Firstly, its closed-loop regulation on actual cylinder pressure along with adaptive and self-tuning algorithms increase accuracy over time and make braking distances more predictable. This allows for greater accuracy in train stopping positioning. Dwell time is also improved thanks to high response times (<800 ms for brake application and release).
In addition to these significant benefits, the introduction of our new-generation DistanceMaster™ wheel slide protection (WSP) based on an adaptive filter, along with our deceleration compensation algorithm, take the use of actual wheel/rail adhesion to a new level. Used together, adaptive WSP and deceleration compensation improve braking performance by at least 50% compared to current WSP systems in standard degraded adhesion conditions. Deceleration compensation maximizes the use of available adhesion along the train in degraded adhesion conditions, or in degraded modes (bogie isolated, downhill, etc.). This makes trains much more resilient to adverse adhesion conditions and dramatically reduces maintenance costs (flat wheels).
Unlocking New System Functions
The patented architecture developed specifically for Regioflexx also opens up the field of possibilities in terms of system functionalities. Embedded dynamic WSP monitoring, for example, provides efficient protection against the consequences of rapidly changing adhesion conditions. This avoids the intervention of the time-based watchdog function and significantly reduces the risk of axle lock. Regioflexx’s monitoring capabilities also enable the use of the available E/D Brake and the emergency brake using propulsion technologies currently available. This allows for the optimization of sizing and reduces stress on the friction brake in the emergency brake. Plus, the Regioflexx braking system provides high-integrity speed information which enables the reduction of redundancies for speed-dependent functions, such as door-opening controls.
Simplifying to Streamline
Every effort has been made to simplify and streamline the architecture behind Regioflexx to make it easier to operate, install and integrate. The system is natively designed to be network-operated, for example. A train/vehicle data bus connection plus a safety loop are all that is needed to control the entire brake system. This allows for reductions in train integration costs and improves overall system reliability.
To comply with interoperability TSI requirements, Regioflexx also features emulations of UIC distributor, multi-stage valve and average load valve, when needed. This reduces the number and complexity of additional pneumatic components along with associated installation and maintenance costs.
For very-high-speed trains (more than 250 km/h) the mandatory wheel rotation monitoring (WRM) system installation is complex and costly in traditional systems. With Regioflexx, on the other hand, the WRM function is natively embedded, eliminating the burden of installing double WSP systems per car. The necessary electronic and pressure release redundancy is fully integrated into Regioflexx. This creates significant savings in terms of installation and maintenance costs.
Another distinctive feature of Regioflexx is its single integrated box (space and weight saving) that includes both electronics and pneumatics as well as several pneumatic valves replaced by software emulations. It offers cabling simplification through network operation, easy functional interfacing to traction and TCMS, and an embedded WRM function. As a result, Regioflexx offers car builders and operators better cost competitiveness compared to traditional solutions.
Easy Maintenance for Best-in-Class Train Availability
In addition to the multitude of advantages offered by Regioflexx’s state-of-the-art technology, the system has been designed for ease of maintenance to ensure maximum train availability. Thanks to the use of adaptive and self-tuning algorithms, Regioflexx offers extended MTBO (up to 15 years) and more stable performance over its lifetime. This means that only one overhaul will be required over a train’s 30-year lifespan. It is also natively equipped with predictive maintenance algorithms. It provides the usual diagnostic messages, but also residual time prior to overhaul and inspection flags based on abnormal consumption and drift identification.
The weight and size of Regioflexx allows a single operator to replace it on a train in less than 20 minutes. The design of Regioflexx and its bracket (installed on the vehicle) allows it to recognize its position on the train automatically, and therefore use the right brake setting for each position. Thanks to this feature, just one part is needed for the entire fleet. Regioflexx is also easy to overhaul. With specialized test benches and a trained and certified workforce, maintenance can be performed at operators’ facilities.
Maintenance of a Full Brake-Control System has Never Been So Simple
Regioflexx maximizes train availability and is fault tolerant, making it a very cost-effective solution. A single failure affecting the service brake can be managed remotely (by the driver or TCMS), while keeping an emergency brake per bogie available to ensure the train will never be stopped unnecessarily during operations.
Regioflexx Prepares for the Trains of the Future!
Regioflexx is set to become to solution of choice for forward-thinking train operators looking for the latest technology to help their trains speed into the future. Several operators around the world are already reaping the benefits of the system’s innovative features. These include native per axle brake control and wheel slide protection. This enables full axle control without additional costs. A single failure per Regioflexx will not affect more than 50% of local bogie emergency braking. This greatly contributes to the highest Guaranteed Emergency Brake Rate (GEBR).
Regioflexx also provides accurate and predictable performance. It offers advanced adhesion management and closed-loop control on brake cylinder pressure. SIL 4 emulated functions contribute significantly to highly predictable braking performance, even in degraded conditions, minimizing performance drift between dry and degraded adhesion conditions.
Regioflexx: a Certified Building Block for Your Train
Wabtec’s Regioflexx solution has received full safety certification from TÜV SÜD, including validation of safety levels associated with each function. In addition, DB Systemtechnik assessed Regioflexx’s compliance with the TSI standards. Regioflexx is also compliant with cybersecurity standards.