Scientists at the U.S. Army Research Laboratory have developed a novel algorithm that enables localization of humans and robots in areas where GPS is unavailable.
According to ARL researchers Gunjan Verma and Dr. Fikadu Dagefu, the Army needs to be able to localize agents operating in physically complex, unknown and infrastructure-poor environments.
“This capability is critical to help find dismounted Soldiers and for humans and robotic agents to team together effectively,” Verma said. “In most civilian applications, solutions such as GPS work well for this task, and help us, for example, navigate to a destination via our car.”
However, noted the researchers, such solutions are not suitable for the military environment.
“For example, an adversary may destroy the infrastructure (e.g., satellites) needed for GPS; alternatively, complex environments (e.g., inside a building) are hard for the GPS signal to penetrate,” Dagefu said. “This is because complex and cluttered environments impede the straight-line propagation of wireless signals.”
Dagefu said that obstacles inside the building, especially when their size is much larger than the wavelength of the wireless signal, weaken the power of the signal (attenuation) and re-direct its flow (called multipath), making a wireless signal very unreliable for communicating information about location.
According to the researchers, typical approaches to localization, which use a wireless signal’s power or delay (i.e., how long it takes to reach a target from a source), work well in outdoor scenes with minimal obstacles; however, they perform poorly in obstacle-rich scenes.
The team of ARL scientists including Dagefu and Verma developed a novel technique for determining the direction of arrival, or DoA, of a radio frequency signal source, which is a fundamental enabler of localization.
“The proposed technique is robust to multiple scattering effects, unlike existing methods such as those that rely on the phase or time of arrival of the signal to estimate the DoA,” Verma said. “This means even in the presence of occluders that scatter the signal in different directions before it is received by the receiver, the proposed approach can accurately estimate the direction of the source.”
The underlying idea is that the gradient of the spatially sampled received signal strength, or RSS, carries information about the source direction.
“Extracting the DoA requires a theoretically grounded analysis to obtain a robust estimator in the presence of undesirable propagation phenomena,” Verma said. “For example, large obstacles cause the RSS samples nearby to become highly correlated (so-called “correlated shadowing”). If left uncorrected, this correlation can seriously bias the DoA estimate.”
The key invention according to the researchers is an algorithm that statistically models the RSS gradient and controls for spatial outliers and correlations.
Importantly, when the signal is extremely noisy, the estimator correctly outputs that no DoA is present, rather than incorrectly estimating an arbitrary direction.
The output is an estimated DoA and associated uncertainty.
The researchers have validated the approach with several publically available as well as in-house collected measurement datasets at 40MHz and 2.4GHz bands, as well as data from high fidelity simulations.
The technique works in conditions of heavy multipath in which classical phase or time of arrival based estimates would fail.
In addition to not requiring any fixed infrastructure, the proposed technique also does not rely on any prior training data, knowledge about the environment, multiple antennas, or prior calibration between nodes.
A journal paper documenting the research has been accepted for publication in the Institute of Electrical and Electronics Engineers Transactions on Vehicular Technology.
An early access version can be found here.
Learn more: Army researchers develop novel technique to locate robots, Soldiers in GPS-challenged environments
The Latest on: Location technology
[google_news title=”” keyword=”location technology” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Location technology
- Transformational Wake Tech Location Opens in Wendellon April 26, 2024 at 11:46 am
Residents of eastern Wake County, local officials and future students got their first look at Wake Tech's newest location, in Wendell.
- Has the Location of Plato’s Grave Been Found in Athens?on April 23, 2024 at 4:30 am
An archaeologist says he has found the exact location of Plato's grave in the Platonic Academy in Athens after deciphering ancient papyri.
- Aldi Clarifies Whether It Is Replacing Cashiers with AI Technologyon April 22, 2024 at 5:03 pm
Aldi tells PEOPLE that customers will still have the option to shop at its grocery stores with a " traditional cashier.” ...
- 7 Beacon Technology Retail Strategies to Increase Saleson April 22, 2024 at 12:20 pm
Your guide to the best in personal financial products such as credit cards, mortgages, bank accounts, and brokerages.
- Forget GPS, three simple words reveal any location in the worldon April 19, 2024 at 1:00 am
When it comes to finding a specific location, GPS is incredible, but let’s face it – nobody is exchanging coordinates. An app called what3words is trying to make finding people and places, as well as ...
- For Dataplor’s data intelligence tool, it’s all about location, location, locationon April 18, 2024 at 5:59 am
If you want to get your product in a grocery store in Mexico City, Dataplor has global location intelligence to help you do that. Founder and CEO Geoffrey Michener started the company in 2016 to index ...
- 3 Logistics Technologies That Can Enhance Retail Customer Experienceson April 17, 2024 at 7:30 am
In the retail world, apart from product price and selection, the customer experience is the single most powerful determinant for repeat purchases.
- Google location tracking deal could be derailed by politicson April 16, 2024 at 3:45 am
Google's plan to pay $62 million to settle allegations that it tracked people even when their Location History setting was switched off may have to be renegotiated based on several objections.… These ...
- What You May Not Know About Real-Time Location Systems and RFID Applications in the Automotive Industryon April 15, 2024 at 8:24 am
But with real-time location technology, you can confirm goods receipt in real time and leverage a more dynamic put away model in parts logistics. Or, at the dealership level, you can use RFID to ...
via Bing News