top of page

Making Sense of Sensor Fusion for Positioning

Updated: 3 days ago



The Key to Accurate and Reliable Location Information


In today’s technology-driven world, accurate and reliable positioning information has become indispensable for numerous applications, ranging from navigation systems to augmented reality experiences. However, achieving pinpoint accuracy in location-based services is no easy feat, especially considering the diverse environments and conditions in which these systems operate. Relying on a single location technology falls short in providing consistent results across all scenarios. Enter sensor fusion, an innovative approach that combines the strengths of multiple sensors to overcome the limitations of individual technologies. This article will guide you through the concept of sensor fusion, explain the difference between absolute and relative positioning sensors, highlight the distinctions between indoor and outdoor environments, and introduce TDK Trusted Positioning’s solutions that leverage sensor fusion to deliver unrivaled positioning performance.


Sensor Fusion: Overcoming the Limitations of Individual Technologies


Achieving accurate and reliable positioning often requires the integration of multiple sensors, a technique known as sensor fusion. By combining the strengths of different sensors, sensor fusion compensates for the weaknesses and limitations of individual technologies. For instance, while GPS/GNSS receivers provide global positioning information, they can be affected by signal blockages in urban environments or dense foliage in outdoor settings. Inertial sensors, on the other hand, excel at providing continuous positioning updates but suffer from drift over time. By fusing the data from GPS/GNSS and inertial sensors, sensor fusion systems can obtain accurate and reliable positioning, mitigating the shortcomings of each technology. This fusion of sensor data enables robust and consistent performance across various outdoor environments and conditions.


Absolute vs. Relative Positioning Sensors: Understanding the Difference


When it comes to positioning, sensors can be broadly categorized into absolute and relative positioning sensors. Absolute positioning sensors, such as GPS/GNSS receivers, provide positioning information with respect to a global coordinate system. These sensors offer a high-level view of the user’s position but may struggle in environments where satellite signals are obstructed or weakened. On the other hand, relative positioning sensors, including inertial sensors and barometric pressure sensors, measure the changes in position and orientation relative to a starting point. These sensors excel at capturing precise movements but may suffer from drift or accumulated errors over time. By combining the outputs of absolute and relative positioning sensors through sensor fusion, a more accurate and robust positioning solution can be achieved.


Below is a list of commonly used sensors in positioning systems, categorized according to their positioning type.  Some sensors may be both absolute or relative, depending on how they are referenced with respect to a coordinate frame.


Absolute Positioning Sensors

Relative Positioning Sensors

GPS (Global Positioning System)

Inertial Measurement Units (IMUs)

GNSS (Global Navigation Satellite System)

Map Matching

Wi-Fi Access Point Systems

Visual Lane Tracking

Wi-Fi Fingerprint Systems

Ultrasonic Range Sensors

Cell Tower Triangulation

Barometric pressure (altitude) Sensors

Visual Light Communication (VLC)


Ultra Wideband (UWB)


Geomagnetic Fingerprint Systems


BLE Fingerprint Systems


BLE Proximity


LiDAR/Camera/Radar Positioning from Maps


Indoor vs. Outdoor Environments: Tailoring Sensor Fusion to Different Settings


The choice of sensors in a positioning system depends on the environment in which it operates. Indoor and outdoor environments present unique challenges and require different sensor configurations. In indoor settings, GPS signals are often weak or unavailable, necessitating the use of alternative technologies such as WiFi access points, Bluetooth beacons, and ultra-wideband (UWB) systems for positioning. In contrast, outdoor environments typically rely on GPS/GNSS receivers as a primary positioning technology. However, the availability of satellite signals can be compromised in urban areas or dense foliage.


In these scenarios, sensor fusion systems that combine GPS/GNSS with other sensors, such as inertial sensors or perception sensors (LiDAR/Vision/Radar), can provide accurate and continuous positioning. By tailoring sensor fusion to the specific requirements of indoor and outdoor environments, reliable and robust positioning solutions can be achieved.


To illustrate the contrasting requirements, the following tables proposes some optimal uses of sensors for Indoor or Outdoor Positioning.  Again, note that many of the sensors can be used both Indoors and Outdoors.


Indoor Positioning Sensors

Outdoor Positioning Sensors

Wi-Fi Access Points

GPS/GNSS Receivers

Bluetooth Beacons

Cellular Networks (Cell Towers)

Ultra-Wideband (UWB)

LiDAR (Light Detection and Ranging)

RFID (Radio Frequency Identification)

Radar (Radio Detection and Ranging)

Ultrasonic

Inertial Measurement Units (IMUs)

Inertial Measurement Units (IMUs)

Barometric

Geomagnetic

Camera-Based Systems


 


In the previous sections, we explored the concept of sensor fusion and its role in different environments as well as its role in overcoming the limitations of individual positioning technologies. Now, let’s delve into TDK Trusted Positioning’s solutions that harness the power of sensor fusion to deliver accurate and reliable positioning performance in various applications and environments.





FAQs: TDK Trusted Positioning Solutions



What is the objective of TDK Trusted Positioning solutions?

Our objective is to accurate and reliable positioning solutions at a price feasible for large-scale implementation, regardless of the application or use case.

How does VENUE work for indoor positioning?

Can TDK Trusted Positioning solutions be used for outdoor applications?

How does RIDE work for 2-wheeled platforms?

How does TRACK provide enhanced vehicle positioning?

How does AUTO enable high-accuracy positioning for autonomous wheeled platforms?

What industries can benefit from TDK Trusted Positioning solutions?

How does TDK Trusted Positioning ensure accuracy and reliability?




Comments


bottom of page