European car-sharing company augments positioning accuracy

More than ever, many people are realizing that sharing a car isn’t such a bad idea, especially in bustling cities where the model offers a sustainable and cheaper alternative to traditional car ownership. Car-sharing is a movement that has been gaining momentum over the last few decades. The late 1980s and early 1990s marked the beginning of this transportation revolution, particularly in Europe. Today, there are nearly 200 million car-sharing users worldwide.

INVERS, a German company based in Siegen, was a true pioneer in the sector. Its visionary founder, Uwe Latsch, crafted a solution in the early nineties that allowed him to travel without the need for car ownership. While studying at university, he created the first car-sharing telematics unit to automate processes for vehicle sharing, initially experimenting with his fellow students.

Once the idea got wheels, car-sharing operators quickly turned their attention to Latsch’s innovation. CarSharing Deutschland Genossenschaft, Dutch operator GreenWheels, and the Singapore Car Club were among the first customers.  

Over the past thirty years, INVERS has grown to provide vehicle-sharing technology to approximately 450 operators worldwide.

Locating the exact position of a car is at the center of the game for INVERS operator partners, especially when a car rental customer terminates the service, and the next driver wishes to locate the vehicle.

The challenge: finding a rented vehicle, even in the most difficult places 

Communicating the precise location of a car to operators when a new user requests the service generally poses no issue. Yet, this can sometimes become a hassle in large cities like New York or Dubai, especially when car renters do not follow parking rules and leave vehicles in places they shouldn’t.

Skyscrapers, tunnels, bridges, and other sources of interference can disrupt satellite signals, leading to inaccurate location data for GNSS receivers. If a customer parks a vehicle near, within, or below these structures, a new user may have trouble locating the rented vehicle. Imagine searching for a rental car, only to find it meters away from where the mobile location app indicates – perhaps on the other side of a street, separated by a tram or a train track. This would inevitably lead to frustration and complaints directed at the car-sharing operator.

In fact, operators have detected situations where the car's location was up to 100 meters away from the position indicated by the GNSS receiver. Although these cases are rare, they still require a solution.   

Dead reckoning technology saves the day

INVERS has been using u-blox's modules since 2015, but in 2018, it explored alternatives to address this issue by installing receivers that integrate dead reckoning and GNSS technology. After several trials, they chose the u-blox NEO-M8L module.

Dead reckoning uses algorithms to calculate distance, direction, and elevation changes to determine a vehicle's position. It achieves this by fusing measurements from GNSS navigation data with those from the Inertial Measurement Unit (IMU).

Even though the solution yielded results, such as tracking vehicles in underground parking garages, there were still errors in some cases. INVERS soon discovered that a significant number of these errors were not due to the GNSS receiver but rather to the installation of the CloudBoxx telematics unit. Operators can install these units in many places, always running the risk of leaving them loose, which would cause vibrations and compromise optimal sensor fusion.      

Since INVERS can’t control the placement of the telematics unit, it decided to implement a method that tailors its service according to each client. Initially, it offers car fleet operators a solution without dead reckoning technology. Later, if an operator reports too many positioning errors from car renters, INVERS can activate dead reckoning technology to achieve better results. Companies whose cars frequently travel under bridges and through tunnels are usually the ones requesting this upgrade.

"u-blox’s modules offer configuration options to activate or deactivate dead reckoning technology – this is a key advantage for INVERS."

-Uwe Latsch, CTO, INVERS

The outcome: switching tracking modes without losing location accuracy

As technology evolves, errors decrease. This is evident in the u-blox collaboration with INVERS, which perfectly reflects the improvements of new versions and the advantages they provide to customers.

With the deployment of the NEO-M8L dead-reckoning GNSS module in all CloudBoxx units used by its car-sharing operator partners to locate vehicles, INVERS has achieved more than 99% reliability in locating cars. While this high level of reliability is remarkable, there remained a small margin for improvement separating the company from a perfect car locating solution.

Through experience, INVERS realized that inaccuracies in car location would occur during transitions between GNSS tracking and dead reckoning, followed by a return to the original GNSS tracking.

The new series of u-blox’s modules, equipped with enhanced dead reckoning technology, proved to be an even better solution. The algorithms used by the NEO-M9V modules can now make more informed decisions about when to rely on GNSS signals and when to trust IMU measurements. This becomes particularly noticeable when a car emerges from a tunnel or when the GNSS signal visibility is poor.

By deploying NEO-M9V modules in a percentage of their car fleets one and a half years ago, the company has further reduced the errors reported by car-sharing operators.  

Perfecting u-blox technology

The latest upgrades in u-blox technology have had a profound impact on positioning solutions, representing a significant advantage for companies like INVERS. This example indeed highlights the ongoing spirit of improvement that permeates u-blox.

Our objective remains to consistently enhance the performance of our modules and chips for the benefit of customers and end users.

Curious about u-blox’s dead reckoning products? You can start by checking out our EVK-M9DR evaluation kit. And what about the latest INVERS offer? Check it out here.