Using mobile technology to deliver better services: Sanergy’s partnership with GSMA and SweetSense Inc.
Sanergy teammates Joseph Lumumba and Lauren Stover are spending the week in Dar es Salaam, Tanzania, at the GSMA Mobile for Development Utilities working group. Joseph and Lauren are presenting the work GSMA has been supporting with Sanergy, using sensors to optimize our waste-collection process.
GSMA has been supporting our partnership with SweetSense Inc., with whom we’ve been piloting the use of cellular sensors in our Fresh Life Toilets (FLTs) to determine the fill levels of our toilet cartridges and more accurately predict when waste collection is needed, and to record when waste collectors visit latrines, and when our Fresh Life Operators request service. Figuring out how best to collect this information would allow us to improve the efficiency of our waste-collection processes, only visiting toilets to collect and remove the waste when the cartridges are at or nearing capacity.
In the first stage of our work with GSMA and SweetSense, we tested three different types of sensors in nine different locations to determine what type of sensor would work best for our larger pilot. Each type of sensor was installed in three locations. We tested using pressure transducer sensors (PT), weight sensors (WS), and passive infrared sensors (PIR), to determine which sensor would best suit our needs. The pressure and weight sensors track the amount of waste while the passive sensor tracks the fill rate and numbers of uses in a particular Fresh Life Toilet.
We looked at the durability of each sensor in situ, as well as its ability to provide accurate information on the fill levels of the cartridges. At the beginning of the pilot, we also evaluated each sensor type based on sensor coverage and its ability to transmit information wirelessly, sensor data volume, sensor downtime and maintenance needs, and sensor accuracy in determining fill rates. As the pilot advanced, however, we updated the criteria to include toilet access, geometric variation between FLT versions, human concerns, and our existing weighing operations.
We found that while the PT sensors were useful for calibrating weight sensor data, they were too fragile to fit within our operating environment. While the WS sensors provided high-quality data, their design only worked for our newest toilets and couldn’t be installed in older FLTs. The PIR sensors were the most practical to use within the network, and they have the potential to fit well into a hybrid model to collect additional information.
At the end of the initial stage, based on the performance criteria collected, we analyzed the data to determine if the PIR sensors, which measure usage would be accurate enough to use in the full pilot. We determined that PIR sensors could be used to accurately estimate both fill rate of the cartridges and total number of uses per day.
We are currently working with SweetSense to modify the PIR sensors to better suit our needs, by installing RFID chips to provide us with additional data streams, including:
- Occupancy sensing, to provide qualitative data about an FLT’s uses between service visits;
- A record of servicing events and time of service to better understand route operations;
- A record of the cleanliness of an FLT at the time of service; and
- A way for Fresh Life Toilet Operators (FLOs) to register a missed collection or if the FLT requires maintenance.
Next month, we’ll launch the full pilot, testing PIR sensors in 40 toilets across the Fresh Life network. We’re excited to see the data these sensors can provide, which will help improve our collection operations, in addition to facilitating communications with our Fresh Life Operators.
This document is an output from a project funded by the GSMA Mobile for Development Foundation, Inc. (GSMA Foundation), which, in turn, received its funding from UK aid from the UK Government. The views expressed are not necessarily those of GSMA Foundation or the UK Government