Driving Advice System – DAS
Frequently asked questions
What is the difference between Energymiser, DAS, and CDAS?
Driving Advice Systems (DAS) and Connected Driving Advice Systems (CDAS) are industry terms describing technology that generates a driving advice ‘profile’ which is displayed to drivers throughout their journey.
DAS providers have different approaches for producing the advice shown to drivers. These approaches typically include:
- Minimised braking
- Using the best driver as a benchmark
- Driving at the lowest speed
- Driving with constant speed and coast
- Driving to an optimal speed profile.
The term Energymiser represents Trapeze’s specific algorithm for generating the driving advice profile. Energymiser was developed by the University of South Australia, using the optimal speed profile methodology, and both organisations work in partnership to this day as we continue developing the product.
Numerous peer-reviewed studies published in academic journals have concluded that the optimal speed profile is the most effective way of generating an advice profile for drivers. This was verified when one of our clients ran a real-world trial of Energymiser against three other providers, and Energymiser came out on top by a significant margin.
Energymiser is more effective than other methodologies because it considers a larger set of variables and the relationships between these variables. The powerful, physics based Energymiser algorithm balances this broader set of variables to generate a robust, reliable, and optimal profile that outperforms more basic methodologies.
The optimal profile created by Energymiser seeks to minimise braking (see 1 above), while maximising coasting (4), and also driving at the lowest speed (3). Instead of focusing on one these points individually, it considers them all simultaneously.
It is worth noting that using the best driver as a benchmark (2) is inefficient because even the best driver will underperform against the optimal profile. This means systems using that methodology are inherently inefficient, because they are benchmarking against a less than optimal profile.
The difference between DAS and CDAS
Before departure, DAS will use its powerful algorithm to generate an optimal profile for the journey ahead using pre-downloaded parameters. The generated advice profile advises drivers on how to operate the train in the most energy efficient manner.
Our CDAS solution builds upon this core DAS platform by enabling trains to communicate with other systems in real time, enhancing train movements across your network. This dramatically helps your network respond to disruption and maintains efficient driving practices and on-time-performance network-wide.
If you want to know more then read our blog explaining the differences between DAS and CDAS in greater detail.
How does DAS work with ETCS and ATO?
While ETCS and ATO aim to enhance railway operations, it is important to remember they are not systems that provide traffic management functions. ETCS primarily ensures safety and interoperability using standardised train control and signalling, while ATO automates train operations to improve efficiency and network capacity. These technologies often complement each other and are frequently deployed together (ATO over ETCS) to attain higher levels of automation and safety.
DAS has already been successful deployed on ETCS-equipped lines, with DAS configured to align with ETCS permanent speed restrictions. This allowed the operator to unlock all the emission and fuel saving benefits DAS provides while also benefiting from the safety enhancements offered by ETCS. For CDAS, Trapeze envisages a simple system whereby DAS advice is given when operating within the ETCS safe speed envelope, and suppressed when ETCS is intervening. Despite some claims made about its benefits, ETCS remains a safety system for maintaining separation between trains. Unlike DAS, ETCS it is not a trip optimisation system.
While ATO systems claim to generate energy efficient speed profiles, our experience suggests they are not as efficient as our DAS algorithm. This is demonstrated by the fact that Trapeze, in partnership with Alstom/Bombardier, delivered a DAS/ATO system for high-speed trains in Spain which combines the benefits of ATO and DAS in a single integrated system. This was made possible through the implementation of one integrated driver display with DAS advice being sent directly to the ATO controller.
Would DAS be a distraction for drivers?
Trapeze’s DAS is designed to minimise distractions and has multiple human factor certifications as a result. This design presents the information in an easy-to-consume manner, enabling drivers to follow energy saving advice in the safest way possible.
Drivers also find the contextual information highly valuable as they are informed of upcoming crossings, danger zones, TSR, and other safety-critical line information ahead of time.
How can DAS reduce SPADS?
DAS helps to reduce a range of scenarios that are stressful for drivers, including SPADs, station over-runs, and queuing. This is achieved by improving drivers’ situational awareness, as the DAS screen provides accurate and updated critical route information that drivers can rely on to complete their journey safely.
How does DAS improve on-time-running (OTR) performance?
Following the DAS advice helps each driver achieve the optimal run, as it allows for factors including track geometry, speed profile, timetable, train characteristics, and train position. The system then calculates the optimal way to drive to the destination on time. Drivers that align their train to the advice will arrive on time and in the most energy efficient way possible.
CDAS takes this to the next level. When OTR is impacted by an unexpected delay, CDAS adjusts the journey profile to help the driver recover lost time safely, reducing knock-on effects that would otherwise impact the rest of the network.
How does DAS support my existing fleet strategy and future fleet strategy?
Energymiser provides a high degree of flexibility and guarantees it can support both your immediate fleet and your future fleet. It guarantees you don’t risk making a short-term technology investment that quickly becomes redundant as you transition to modernised locomotives or train units (or others).
We can guarantee this because train types, energy sources (diesel, electric, hybrids, ammonia, hydrogen etc), and other variables are all data inputs the system uses to generate the advice profile. This allows these inputs to change without compromising the technology’s effectiveness, as you benefit from the cost and emissions savings DAS delivers now and into the future.
A hypothetical example to illustrate this flexibility:
A driver receives his work order for the day, and he will be transporting cargo (bulk, etc) or passengers from the port to the airport. He will depart the port in a diesel-powered train that has been in operation since 1990.
The driver enters the cabin, places the iPad in the iPad holder, and loads the DAS application. Once DAS has loaded, he manually (or automatically depending on configuration) inputs the data required for that journey, including train type, weights, and line variables.
The driver then executes the journey and drives in according with the advice, maintaining a high degree of compliance. This results in the driver arriving on time and saving approximately 8% more diesel than the baseline run.
After a short break, the driver is required to complete the return journey, travelling from the airport to the port. This journey is operating a modern hydrogen powered train. He enters the cabin places the iPad in the iPad holder and follows the same process as that outlined above.
He executes the journey and again drives in according with the advice while maintaining a high degree of compliance. This results in the train arriving on time and saving approximately 10% more hydrogen than the baseline run.
How long does it take to implement DAS?
Our experience has shown that operators purchasing a standard DAS deployment are able to begin capturing fuel and emissions savings around 4 months after commencement of delivery. Of course, implementation can vary depending on the deployment approach chosen by the customer.
We are proud of our ability to rapidly deliver a highly flexible, reliable, and effective solution that can save 7–15% on fuel and emissions.
What hardware does DAS operate on?
DAS can be deployed into screens already present in the cabin, including Apple, Android devices, and Inelmatic units. DAS has an immense amount of flexibility, and we can work with you to provide your drivers with energy saving advice in a way that best suits your operation.
How long does it take drivers to activate DAS before the journey?
The system can be configured in different ways to meet your business and timing needs. Typically, freight operators have more time at the start of a journey and elect for drivers to manually enter the necessary data. Passenger trains have tighter timing requirements and usually opt to save time by automating the login process. Each circumstance and need is different and this is something we can discuss with you.