pedestrian dead reckoning

PNI Sensor, a member of the SEMI-MSIG Positioning, Navigation and Timing (PNT) Technical Advisory Council, is developing advanced tracking systems that promise to increase industrial worker safety.The availability of low-cost GPS jamming and spoofing technologies renders GPS-only solutions for location and navigation an increasingly dangerous and ineffective choice for the dismounted soldier in a battlefield environment. This threat to armed forces has spurred development of new self-contained location and navigation technologies for defense applications — an innovation that offers significant advantages for commercial applications.Though not as complex and mission-critical as in defense, self-contained location technology is also essential in commercially available industrial applications. That’s particularly true for workers in industrial sectors such as utilities, mining, and construction, and in environments with lone or remote workers, such as first responders. While jamming and spoofing are not a threat in the industrial sector, determining the precise location of workers in GPS-denied environments is fundamental to ensuring their safety. This makes it a priority to adapt any self-contained, non-infrastructure-based location technology — which was first developed for the modern dismounted soldier — to industrial applications.Bodies in MotionInertial solutions are very difficult to implement properly, even without the challenges uniquely created by human motion dynamics. On a construction site, for example, workers tend to cover a wide range of disciplines: supervisors, electricians, iron workers and equipment operators, among others. While performing their jobs, construction workers change locations, both indoors and outdoors, and perform dynamic motion such as crawling, ducking and climbing. These are all motions that are very difficult to model using traditional adaptive filtering techniques, which are typically applied in vehicular inertial navigation platforms, such as aircraft, ships and tanks. Even if existing inertial navigation systems could be made size, weight, power and cost (SWaP-C)-compatible to be body-worn, their performance accuracy would still need to satisfy the application’s requirements. To properly determine a worker’s precise location to ensure safety on job sites and in remote locations, we must tackle the combined challenges of SWaP-c and human dynamic motion. That’s the most effective approach for creating a complementary positioning technology that augments GPS or other infrastructure-based location systems.To address these challenges, we need to build a high-performance inertial measurement solution using commercially available MEMS inertial sensors. The issues of bias drift error and low sensitivity have traditionally made such sensors practically useless for any meaningful inertial tracking. Fortunately, this is no longer the case. We now have sensors that already conform to the necessary SWaP-C requirements for the application, and have the additional advantage of high dynamic range of measurements without saturation errors, which helps to reduce high-force and rapid movement-induced errors, promoting greater accuracy.Thus, a path forward is emerging. The current generation of high-performance MEMS gyros can now inertially track workers’ locations to step-level resolution very well for up to 30 minutes — without significant location errors due to bias or scale errors. That’s an order of magnitude better than previous generations. With the new MEMS gyros, errors typically remain less than 2% of distance travelled over that time period. Strategically applying algorithm improvements with higher levels of magnetic corrections has the potential to bring that accuracy down even lower, to less than 0.5% of distance traveled for durations of one hour or more. What’s more, the improved gyro and accelerometer bias, gain, and signal-to-noise (SNR) performance allows for better magnetic anomaly rejection. This enables finer and more sustained gyro bias corrections in the fused solution, which creates a system greater than the sum of its parts. We believe that these newer systems will promote greater worker safety at a truly affordable price.PNI Sensor, a member of the SEMI-MSIG PNT Technical Advisory Council (TAC), is developing a tracking system that combines the best elements of the newest-generation MEMS devices with an electronic compass that uses advanced magnetic anomaly detection and rejection algorithms. Based on PNI’s latest attitude and heading reference system (AHRS), the novel PNT system employs a unique Kalman algorithm that intelligently fuses its reference magnetic sensors with gyros and accelerometers. In conjunction with this work, PNI Sensor has developed advanced pedometry functionality for use in its tracking system for very high dead-reckoning tracking performance used in defense industry applications. PNI is initially designing that system to track dismounted soldiers and special forces operating in GPS-denied or contested environments.For more information about PNI Sensor’s advanced location and navigation technology, please visit PNI Sensor. To learn more about the SEMI-MSIG PNT TAC, please contact Carmelo Sansone, director, MEMS Sensors Industry Group.George Hsu is a founder and CTO of PNI Sensor. He has focused his career on the sensor industry, having invented several magnetic sensor breakthroughs, including the magneto-inductive technology, the core of today’s electronic compassing in the automotive, consumer, scientific and military markets. Hsu is a graduate of Stanford University School of Engineering, holds several patents, and is a much-published author of technical articles on sensor theory, design and applications. He is an active member of the MEMS Sensors Industry Group PNT TAC.About the SEMI-MSIG Positioning, Navigation and Timing ProjectMEMS Sensors Industry Group (MSIG) created a member-based PNT TAC to identify and pursue PNT system innovations for GPS-denied environments. To that end, MSIG solicited proposals from its membership for the SEMI-MSIG PNT Project, a U.S. Army Research Laboratory-funded R D project. PNT committee members that have secured funding are pursuing R D platforms that improve accuracy and performance. Platforms may include software, hardware, and advanced packaging requirements of optical and MEMS-based positioning and timing systems.

Tracking and localization technologies typically integrate with Wi-Fi and Bluetooth signals to pinpoint the location of people and objects. But what if a venue can’t install beacons or routers, or afford to deploy Wi-Fi or Bluetooth networks? Thanks to a combination of proprietary algorithms, advanced sensor fusion and the natural geomagnetic field, GipStech, a spin-off of Università della Calabria, built an indoor localization and navigation technology platform for accurate localization in the absence of an adequate GPS signal.Ahead of the SEMI MEMS Imaging Sensors Summit, 25 to 27 September 2019 in Grenoble France, Serena Brischetto of SEMI spoke with Gaetano D'Aquila, co-founder and CEO of GiPStech, about sensor fusion, augmented GPS applications and the future of indoor localization. Join us in Grenoble to learn more about GiPStech and meet other MEMS, imaging and sensors experts. Registration is open online.SEMI: Early this year GiPStech completed a test deployment of the first high-precision, infrastructure-free navigation system at Tokyo Shinjuku metro station in Japan. This is the busiest transportation hub globally! What were the main challenges you faced and how did your technology enable such a highly complex indoor localization?D'Aquila: As you mentioned, Shinjuku station in Tokyo has been registered in Guinness World Records as the busiest transportation hub globally. With 36 platforms, 200 exits and countless corridors and connections, it is easy to get lost there, especially for foreigners and tourists. On the other hand, this scale and complexity makes it unfeasible and expensive to install Bluetooth or similar infrastructure for standard indoor localization.For this reason, we needed to provide a cost-effective indoor localization technology without installing any kind of artificial supporting infrastructure. Thanks to our GiPStech patented multi-sensor-fusion localization stack and the high density of public Wi-FI networks, it’s possible to determine when passengers are inside the station. The public Wi-Fi networks signals were fused as an additional source in GiPStech's sensor-fusion platform to complement the inertial and geomagnetic engine and deliver very accurate results across the entire station. The tests performed in the station also demonstrated that the localization system can even detect the floors where travelers are walking. Now we are ready to roll out the same setup in other stations and environments.SEMI: You are not the first to pursue infrastructure-free indoor localization, but your technology platform seems to be very accurate in bringing precision, stability and consistency to the user experience. What lead to those advancements and incredible results?D'Aquila: Our key differentiating factors are built in the approach we created after years of research and development. One differentiation, of course, is related to our expertise and know-how about how the geomagnetic field can be used as a driving signal for the localization process.During R D we constructed and patented a modular multi-sensor-fusion software stack to solve any kind of localization problem, mainly in indoor environments. We started from a single-signal approach based on the employment of the geomagnetic field as a localization signal. But, mainly due to the very inaccurate devices chosen to measure the geomagnetic field, such as the smartphones that everyone carries in their pockets, we noticed that this single-signal approach is accurate but not reliable because it is strongly affected by a key weakness – the quality of sensor in the device.SEMI: How long did it take for you to solve this issue?D'Aquila: We started to integrate other signals within a few months after the first field tests related to the employment of the geomagnetic field alone. We also began to develop a software platform that could fuse any signal source (natural or artificial) available in the environment to preserve the reliability and accuracy of the localization system when some of these signals are temporarily affected by poor measurement quality. This is our differentiating factor today. We can re-configure our software platform to provide the best reliability and accuracy with the lowest artificial infrastructure in almost any context – from outdoor in a seamless way to indoor and vice versa.SEMI: GiPStech’s inertial engine is one of your cutting-edge technologies that completes your advanced indoor navigation and localization software stack. How do you see the technology evolving?D'Aquila: The inertial engine was one of our first technology modules mainly developed to enhance reliability, smooth the signals and reduce the computational power requirement of our geomagnetic localization approach.After a while, together with a third party that evaluated the performances of our module, we noticed that this module not only can be used as a self-standing localization technique, but it can also deliver high accuracy mainly in PDR (pedestrian dead reckoning) applications.Today our PDR is itself a black box with embedded subsystems. Besides some filtering modules, it includes a state-of-the-art step detector that detect steps even when the person changes the smartphone position and location (not only in the hands but also in backpacks or pockets) and an advanced step validation module that identifies and rejects fake steps.If you’ve ever used a commercial fitness tracker attached to your wrist, you know that in most cases if you move your arm the device will counts some steps that, of course, are not real. Our step validator solves this problem by detecting only real steps – a very important capability that allows our PDR to be employed as a self-standing inertial navigation system. We developed the PDR with strong attention to maintaining low requirements for the computational power and memory footprint. These additional characteristics makes the PDR very interesting even for a direct integration of the software at the silicon level in modern MEMS sensors.In a nutshell, the ability of MEMS sensors to run directly an embedded software module will drive technology enhancements that will allow some of the functionalities now available through an external application processor, such as those in smartphones, to move to a lower level (in the silicon). This, of course, reduces power consumption while even increasing the number of value-added services, including localization services, that could be built directly on top of the MEMS without requiring external software and/or application processor.SEMI: Do you think indoor localization will be more applicable in the next 10 years in areas such as Smart manufacturing, travel, healthcare, entertainment and retail?D'Aquila: Several market reports and our business development experience lead us to assess which sectors are of greatest interest for the application of indoor positioning technologies. They include the following. Industry (manufacturing logistics) Healthcare (tracking of assets, patients and doctors) Big installations (visit experience for museums, fairs) Airports stations (both for travelers and for resource and operation management) Large distribution (user profiling and influencing of the purchasing behavior) Indoor localization is a key enabling technology. Adoption, mainly in these sectors, was limited by the unfavorable tradeoff between cost and benefits. Our indoor localization technology aims to overcome those tradeoffs to make its adoption much more cost-effective while providing the best possible reliability and accuracy.SEMI: What are your expectations regarding the summit in Grenoble, and for the future of the sensors technology ahead? Where are we heading?D'Aquila: Many sectors would benefit from indoor localization technologies. MEMS, imaging and sensors are driving innovation and explosive demand for transportation, medical, mobile, industrial and other IoT applications. But these devices also constitute the basic building blocks for the development of reliable and affordable localization technologies.In outdoor environments we are pretty covered by the GPS. Indoors, where we spend more than of 80 percent of our time, similar types of services are coming to the market now and becoming more reliable over time.This Summit facilitates the direct interaction between different stakeholders to act at different points in the MEMS sensors value chain. Indoor localization was an emerging technology unrelated to the sensors ecosystem until now. Today, indoor localization must leverage MEMS sensors to be effective and reliable. In the future, localization technologies will be embedded directly in silicon to deliver the best performance at a lower cost to increase their adoption for more applications.Gaetano D'Aquila served as research fellow from 2002 to 2004 at the CNR and as an assistant teacher at the University of Calabria. From 2003 to 2014, he worked in the industry first as a security consultant for Telcos and Banking in Value Team S.p.A. and then as project manager at Infomobility S.p.A., where he coordinated research and development and strategic activities in the automotive and auto insurance industries. In 2014 he co-founded GiPStech and is its current CEO. He has published several papers in scientific journals and has filed for seven patents, three of which have been granted in the U.S. and Europe. Gaetano has a MSc in Computer Engineering and a Ph.D. in Science and Engineering of the Environment, Buildings and Energy from the University of Calabria, Italy.Serena Brischetto is a marketing and communications manager at SEMI Europe.