Operational

How does the Acorn system work?

The Acorn Tag is an RFID tag installed at regular intervals along the train line. When a train passes over the tag, it reads and writes a range of performance data to support quick adjustments in operations. Unlike much of the infrastructure required to support industry-standard train control systems, the Acorn Tag is inexpensive and easy to install.

What is the difference between Acorn other modern signaling systems such us ERTMS and CBTC ?

The key difference between Acorn and these systems is that trains can run autonomously under driver operation whereas ETRMS and CBTC require a communications network and the Route Control center to issue driver movement authorities otherwise the trains may not move.

Where does your solution run?

Acorn makes use of existing closed communications systems such as Wi-Fi or Bluetooth for onboard communications.

Has this system been deployed on a railway system?

The Acorn system itself has not been deployed on an active railway, but the underlying RFID technology has been deployed on rail systems in several countries including Austria, Australia, China, France, and South Africa. These systems employed a read-only version of RFID not the enhanced read/write functionality of Acorn.

How do the Acorn tags handle extreme weather conditions?

The tag electronics are encased within a hardened, weather-proof material that is impact resistant. The tags remain operational when submerged in water or covered in snow and ice. RFID tags have been used in the rail environment and have withstood extreme weather.

Does the Acorn system automatically drive the trains?

Acorn’s flexible system can be integrated with the trainset to enable autonomous train operation or provide information to a train driver for manual operation.

What information does the Acorn system provided to the train driver?

The Acorn system’s driver display is customizable, but the recommended information to display includes current train location, current speed, civil speed, schedule status, and track layout ahead to identify trains ahead, switch points, or stations.

What other operational functions can the Acorn system provide?

The Acorn system is a fixed block signaling system with very small block lengths to provide a similar functionality as a moving block signaling system, while providing many other key railway functions. This includes Cutover Integration (Shadow Mode option), Multiple Fallback Modes, Launching Trains, Work Zone Protection, System Diagnostics, ATP, ATO, Positive Train Control by default but the Acorn system can also be extended to Passenger Wait Time Information, Yard Management and Rail Fleet Management.

What protections are there against vandalism?

The Acorn tag is encased in a hardened durable material and fastened between the rails providing physical protection. Built in redundancies also ensure that if a tag is removed, the train operation is not impacted. Depending on the tag installation spacing and the operational requirements of the Railway Operator, the trains can continue to operate with multiple sequential missed readings.

Does the Acorn system use sole source equipment?

Acorn was designed to be open source to allow for a diversity of manufacturers. Acorn’s patented technology (hardware and software) is licensed by Acorn to multiple vendors for construction and delivery. This approach ensures the system’s operator is not locked into buying parts from a sole source and can instead choose from a supplier in a competitive market.

Technical

How are the Acorn tags powered?

The Acorn tag is a passive RFID tag and is powered by the electromagnetic energy transmitted from the Acorn reader mounted on the underside of the train, so there are no batteries or external power supply required.

How does the Acorn system work at interlocking areas?

The Acorn system also includes Type-2 tags that have a hardwire interface enabling direct connection with trackside equipment such as interlocking controllers.

Does the Acorn system control switches in interlocking areas?

The Acorn system does not provide the interlocking or switch control functions and is instead intended to interface with a controller. The Acorn system can be integrated with the controllers as needed by the Railway Operator.

What type of demand does the Acorn system put on the Communications Network?

The Acorn system uses local onboard processing to provide movement authority for trains, removing the need for communication to Wayside Equipment as well as removing the need for low latency communications from the Route Control Center (RCC). Instead, the RCC only needs to receive the small 64-bit word from each train.

Is the Acorn system a moving block signaling system?

The Acorn system is a fixed block signaling system with extremely small blocks, half the distance between two tags, with tags typically installed every 25 feet. Since the fixed blocks are so small, the Acorn system mimics the performance of a moving block signaling system.

How does the Acorn system handle steel dust?

In a track environment, there can be large quantities of steel dust. This steel dust will not impact operation, as demonstrated by RFID technology deployed in similar environments. The electronics within the Acorn tag are surrounded by a hardened weatherproof material, which will prevent steel dust from damaging the equipment. 

In the event of an Emergency Brake, how is the train behind notified?

To provide a sufficient buffer for the train behind, a train that needs to emergency brake will immediately write its status to all tags underneath the train. Therefore, the following train will read information about the braking status of the train ahead before the location that the braking occurred.

How can tags be used to ensure train speeds are safe?

Using the on-board dashboard, trains will be able to read a tag and then reference what speed can be traveled safely. This speed, known as the Rail Visual Range, is used when all normal communication has failed and the train is reliant on the on-board systems for moving along the track. At each tag along the track, the on-board system is informed of the track’s maximum speed, any temporary speed limits, and planned speed.   

What is the Rail Visual Range?

The Rail Visual Range (RVR) is the speed at which a train can travel at a given location and be capable of stopping before reaching any obstacle in its visual sight line. The RVR is specific for each tag along the track and based on track geometry, weather conditions and train profile.

Has there been a RAMS analysis for Acorn?

In a scenario where tags and readers failed 15% of the time, the system would still operate with reliability in the region of five nines. A full RAMS analysis would need to be undertaken for a new installation of Acorn; however, preliminary calculations have been done to provide a high level of confidence.

What security does the Acorn system have?

All well-postured systems have multiple layers of security creating a Defense in Depth. The Acorn system follows this industry-wide strategy and has an added layer of defense by also using software redundancy. Software redundancy is a common technique used by the Aviation industry to ensure fail-safe operation, where a version of software is independently developed two or even three times with all versions run simultaneously in the overall system.

Does Acorn use SIL 4 rated equipment?

Acorn uses a patented solution to leverage multiple lower-rated Safety Integrity Level (SIL) components working together simultaneously to achieve a higher SIL rating for the overall system. Acorn uses SIL 2 rated ARM processors onboard each train car that tie together to create an array of processors resulting in a SIL 4 rated overall train set. All SIL ratings are finalized as part of the specific railway implementation.

How often do Acorn Tags need to be replaced in the field?

The RFID technology used for Acorn Tags allows for 1 Million write cycles (unlimited reads). With a 2-minute headway and 24-hour operation, Acorn Tags would need to be replaced roughly every 4 years. The read/write limits have been tested by the manufacturer but will also be validated in system testing.

Replacement can be done by a 2-3 person team, covering 6 miles in an 8-hour shift during overnight or reduced service periods, or in a shorter time frame with a robotic bogey that replaces the tags autonomously.

Does Acorn use LIDAR or cameras for vision?

Acorn does not require the use of LIDAR or cameras to operate, however the use of these technologies could optionally be implemented to augment or improve the Rail Visual Range.

How does the Acorn System protect Emergency and Maintenance workers?

Temporary speed restrictions or stops can be written to Acorn Tags to create safe zones for Emergency or Maintenance work. These restrictions can be written by a train at the request of the RCC or by a secure mobile device on the trackside.

How does the Train get its movement authority from the Acorn Tags?

After reading an Acorn Tag, the onboard ARM processor will know the characteristics of the train ahead. The ARM processor will then reference the onboard databases to receive information such as line speed, rail visual range and schedules. Using the Tag information, and the database information, the processors will determine the correct movement authority.

Fleet management

How is the Acorn system used for fleet management?

When installed in a rail yard, Acorn’s fleet management feature allows operators to track the history and performance data of each car and allows for individual car tracking in the depot/yard. This provides operators an extremely efficient and data-rich opportunity to track, re-arrange, and plan maintenance on an individual car basis.

What additional equipment is required for Acorn Fleet Management?

Acorn fleet management is cost effective and easily installed. As part of the Acorn system implementation, an Acorn reader is already installed on every train car and no additional on-board equipment is required. In the field, the same Acorn tags are installed along the maintenance and yard tracks with no cabling or additional power required. 

Commercial

What is your business model?

Acorn develops patented technology (hardware and software) that we license to multiple vendors for construction and delivery. Acorn addresses the global market and can be implemented on new or existing systems.

What is your development plan and roadmap?

The underlying technology has been proven in controlled testing environments with parameters that demonstrate functionality at 90 mph. We are currently working with Boyce Technologies to develop a fully operational prototype suitable for installation on a test track. We are also developing a scale model that will demonstrate all features of the system, including emergency services and route changes. 

Who are your existing customers?

Acorn has received interest from multiple transit authorities and industry representatives and pre-existing industry technology providers and is currently being manufactured in collaboration with Boyce Technologies.

Do you have any ongoing or scheduled beta programs / pilots / proof-of-concept with customers?

An operational prototype is up and running, and the system has been tested at the we next expect to showcase the technology with existing transit authorities and vendors. We would expect our system to be ready for shadow mode by September 2020 and are in discussions with multiple transit authorities for pilot programs.

Please list your leadership staff and their roles

Raj Patel – CEO; Ken Garmson – Inventor and CTO; Rebecca Birmingham – Director of Development, TC Chew – Board Director

How do the team members/founders know each other?

Acorn originated as an Arup Venture, with the core team working on its development for the past two years. Once the technology was patented, Acorn systems, Inc. was spun out as an independent company.

Does your company have all legal rights to code?

Yes, and we own the patented Acorn system.