Integrate an embedded GPS system in a bicycle which collects data and reconstructs a user’s route.
- Embedded systems
- Specific Services:
- Proof of concept
- Problem resolution
- Energy optimization
Proofs of concept required by the client and delivered by Spiria.
Number of docked bicycles that can simultaneously send data to the kiosk, thanks to Spiria’s system.
Number of hours it took our “embedded” team to carry out this mandate.
The Challenge | Acquiring Crucial Data
PBSC was looking for expertise in embedded systems to integrate a wireless system that traces the route taken by each user into their shared bicycles in New York (CitiBike). The data had to be transmitted to the stationary kiosk terminals when the bicycles were docked. The kiosk then sent the information to the central server to be synchronized and processed.
For PBSC, having data for every route would allow them to:
- Quantitatively evaluate the environmental gains generated by the New York CitiBike service. This produced tangible proof of the CitiBike project’s environmental benefits (reduction of CO2 emissions) and allowed them to pursue more grants and environmental financial incentives.
- Establish user loyalty by using the data to highlight the benefits of their use of CitiBike: calories spent, ecological footprint, etc.
PBSC wanted Spiria to build a proof of concept and a full technical development plan based on Montreal's bicycle rental service.
Required proofs of concept address four major points
Comparative data analysis was used to determine whether a bicycle was used in a rural or urban environment.
The GPS system’s ability to send data through the radio frequency module integrated into each station’s kiosk.
Downloading logic and protocol to optimize the energy available when stopped.
Ensure that a bicycle docked at the furthest terminal can still send the collected data to the station’s kiosk.
The energy produced by the dynamo in the pedaling system starts up the embedded GPS system in the bicycle and collects data during the ride.
Transmission of data to the kiosk’s radio frequency module. At this stage, the GPS has approximately 3 minutes of power to transfer as much data as possible to the kiosk.
The radio frequency module receives each bicycle’s data. It then sends this data to the server through its wired antenna.
Receives the GPS data via cellular network (3G). It synchronizes the data to reconstruct the route taken by each bicycle and compiles information: time, environmental footprint, calories spent, etc.
Summary of Issues
For this large-scale embedded project, Spiria resolved hundreds of issues, several of which were major:
- Managing to collect precise GPS data at regular intervals (6 seconds): longitude, latitude, the bicycle’s identifying address, schedule, etc.
- Ensure that the environment (clear or obstructed) would not compromise the integrity of the data used to reconstruct the final route.
- Optimize the power available while the bicycle is stopped and only has access to power saved during pedaling: choice of supercapacitors; protocol and adapted download logic during the transmission of data to the kiosk.
- Ensure that the radio frequency module is able to receive a large amount of data when a several bikes are simultaneously docked at the same station.
An Overview of the Work Undertaken
Spiria’s work focused on the integration of components and their ability to carry out the desired commands and to solve problems.
The Embedded GPS System
Located in the bicycle
of the Embedded GPS System
Houses the Atmel ATmega128RFA1 microcontroller allows the execution of the SNAPpy source code.
Spiria modified the script for data sequences.
Spiria has minimized the size of data packets, optimizing the collection and transmission of data. This way, the energy gain results directly from the data sending and receiving protocol.
Also houses a radio frequency antenna that communicates data to the kiosk module using an optimized protocol.
Other components of the embedded GPS system:
The memory Reads, writes and saves the GPS data processed by the microcontroller, then sends it back when the integrated antenna is used to transmit data to the kiosk.
Spiria has developed saving and storage protocols that optimize memory space and time available during data processing.
The supercapacitors They store the energy produced by the dynamo installed in the bicycle. The GPS is therefore powered during the ride and can send data to the kiosk when the bicycle is docked.
The radio frequency module Located in the kiosk
This antenna receives the saved GPS data. Using an external antenna ensures that the radio frequency module receives data even from bicycles docked the furthest away from the kiosk.
The radio frequency module
Receives the collected data which is transmitted by the bicycle’s embedded system when docked. The data is transferred onto a file that, when completed, is transmitted to the central server.
The Atmel AT91SAM9G20
Spiria has modified the logic within its code so that the microprocessor can report the number of GPS points received and the time used to receive them.
This modification allowed for the collection of key metrics for proof of concept validation.
Using radio frequencies (RF), it receives the data transmitted by the GPS system (bicycle) via external antenna. Also powered by an Atmel microcontroller, it sends data to the ARM microprocessor.
At the end of the project, the above system, proofs of concept and development plans including Spiria optimizations were successfully delivered to the client.