NovAtel Inc. announced a new initiative and engineering team to develop functionally safe GNSS positioning technology for fully autonomous applications. The company leverages its extensive experience developing safety-critical systems for the aviation industry to meet the future safety thresholds required for driverless cars and autonomous applications in agriculture, mining, and other government, military and commercial markets.
In early 2015, NovAtel formed a specialized Safety Critical Systems Group of engineers with backgrounds in functional safety as well as all aspects of GNSS and inertial navigation systems (INS) technology. The Safety Critical Systems Group is focused on creating positioning products that will meet the exceptional performance and safety requirements of autonomous vehicles at the necessary production volumes and at the required price point.
The company has extensive background working within safety critical requirements. Michael Ritter, president & CEO stated, “Aviation in North America relies on NovAtel technology to ensure safe navigation and landing.” Ritter added, “The Federal Aviation Administration’s WAAS, and other global Space Based Augmentation Systems (SBAS), have relied on certified NovAtel GNSS receivers for many years as the foundation of their systems. With full GNSS signal and constellation support needed to solve the performance criteria of autonomous driving, NovAtel is uniquely qualified to deliver the optimal solution that will keep us all safe as we drive the autonomous highways of the future.”
Jonathan Auld, Novatel’s director of Safety Critical Systems.
NovAtel manufactures high-precision GNSS receivers, antennas and subsystems, with expertise in sensor integration, specifically that of GNSS and INS. Through its TerraStar correction service, NovAtel also offers a global Precise Point Positioning (PPP) correction solution that is already designed for safety-of-life applications.
With work underway for more than a year, NovAtel plans to achieve ISO/TS 16949 compliance by the end of 2016. This is an early key milestone in the Safety Critical Systems Group’s path, to be followed by an ISO 26262 compliant product.
Jonathan Auld is director of Safety Critical Systems at NovAtel. He first joined the company in 2000 and has held positions as a GNSS test engineer, test group manager, director of technology development, and director of portfolio management.
STMicroelectronics and Israel-based Autotalks have announced their fusion of GNSS technology and V2X ranging.
The new V2X-Enhanced GNSS ensures authenticated and secure vehicle localization for extreme accuracy and reliability of positioning information, especially in urban canyons, tunnels and parking structures, where accurate absolute and relative positioning-to other vehicles and infrastructure-is critical in progress toward semi- and fully-autonomous vehicles.
STMicroelectronics is a semiconductor company, and Israel-based Autotalks is a V2X-chipset market company involved in the first wave of V2X deployments.
Development of V2X-Enhanced GNSS builds on the companies’ successes in co-developing a V2X chipset that connects vehicles to other vehicles and infrastructure within wireless range for safety and mobility applications, the companies said in a press release.
The promise of efficient, coordinated, and safe driving of autonomous cars can result only from the accurate positioning that the fusion of GNSS with V2X technology achieves, the companies said.
“Autotalks fully recognizes that autonomous driving requires equal measures of reliability, accuracy, and security and no driver would sacrifice any of these,” said Hagai Zyss, CEO of Autotalks.
“Our solutions have been architected from the beginning to enable automated driving and because we recognize positioning for autonomous vehicles as critical, Autotalks, with ST, continues to optimize accurate V2X positioning-and we believe that our customers understand the value and potential.”
V2X-Enhanced GNSS technology, when coupled with V2X-enabled infrastructure, can uniquely provide absolute positioning to vehicles to assure lane-level accuracy. This precision improves navigation in urban canyons and tunnels and is also being used to develop myriad new applications, such as autonomous on-street and in-garage parking and available-spot identification.
“To fully realize the safety, convenience and other benefits of autonomous driving, we need confidence in the security, reliability and accuracy of the communications between our vehicle and its surroundings to know precisely how close we are to things, whether — and in what direction — they are moving, and what they are telling us — such as when there are roadworks or an accident ahead,” said Antonio Radaelli, director of Infotainment, Automotive Digital Division, STMicroelectronics.
“Building upon our successful collaboration with Autotalks, we are combining ST’s state-of-the-art positioning technology and roadmap for high-precision Automotive GNSS supporting satellite signal authentication with Autotalks’ expertise in advanced signal-processing algorithms for ranging, to smoothly pave the road to secure, accurate, and reliable V2X-Enhanced GNSS.”
Field trials in an Asian country, monitored by a government agency, are being used to test this technology in 2016.
The United States Federal Aviation Administration (FAA) and its government partners are expanding research on ways to detect “rogue” drones around airports. Together, they are evaluating drone detection technology at John F. Kennedy International Airport (JFK) in New York.
Over the last two years, the FAA has received numerous reports from pilots and residents about unmanned aircraft systems — UAS, or “drones” — around some of the nation’s busiest airports, including JFK.
“We face many difficult challenges as we integrate rapidly evolving UAS technology into our complex and highly regulated airspace,” said Marke “Hoot” Gibson, FAA senior advisor on UAS integration. “This effort at JFK reflects everyone’s commitment to safety.”
Terminal 6 at JFK Airport. (Photo: New York Photo Gallery)
Beginning May 2, the FAA conducted evaluations at JFK to study the effectiveness of a Federal Bureau of Investigation (FBI) UAS detection system in a commercial airport environment. Five different rotorcraft and fixed-wing UAS participated in the evaluations, and about 40 separate tests took place.
The JFK evaluation involved extensive government inter-agency collaboration, and cooperation from industry and academia. The tests expanded on research performed earlier this year at Atlantic City International Airport.
In addition to the FAA and the FBI, the agencies combining forces in this research included the Department of Homeland Security (DHS), Department of Justice, Queens District Attorney’s Office and the Port Authority of New York and New Jersey. DHS and the FBI want to identify unauthorized UAS operators for law enforcement purposes, and the FAA’s mission is to provide a safe and efficient airport environment for both manned and unmanned air traffic.
“We applaud the FBI and FAA for their efforts to detect and track unmanned aerial systems (UAS),” said Thomas Bosco, Port Authority aviation director. “We look forward to supporting continued U.S. government efforts to identify and deploy countermeasures to neutralize the threat posed by rogue UASs.”
The team evaluating the FBI’s detection system also included contributions from one of the six FAA-designated UAS test sites. The Griffiss International Airport test site in Rome, New York, provided expertise in planning the individual tests as well as the flight commander for the tests and two of the UAS used.
The FY 2016 Appropriations law mandates that the FAA continue research into detection of UAS in airport environments. The agency is continuing to formulate an inter-agency strategy to evaluate detection systems in a variety of airport environments.
Penton’s TU-Automotive has unveiled the agenda and speaker line-up for TU-Automotive Detroit 2016, which is being held June 8-9 in Novi, Michigan. The 16th annual conference and exhibition is dedicated to innovation in automotive technology, covering connected cars, autonomy and mobility.
At TU-Automotive Detroit 2016, the city’s automakers — Ford, General Motors and Fiat Chrysler Automobiles — will join international OEMs to discuss their vision for how the car can become the leading “node” of the Internet of Things (IoT), Penton says in a news release.
The 80-plus session agenda and more than 150 speakers will focus on automotive’s leading role within the rapidly expanding connected world, collaboration of efforts, resources and competencies is needed within companies and across the industry.
“Last year we saw the emergence of three core trends in automotive: connectivity, mobility and autonomy,” Gareth Ragg, managing director of TU-Automotive, says in the news release. “This year, these are coming together to form one pillar in automotive strategy, connecting with the wider connected world.”
3,000 are expected to attend this year’s event, which will cover connectivity, ADAS, mobility models, insurance, data, infotainment and more.
Keynote speakers from Ford, GM, Zipcar, Nissan, NHTSA, Jaguar Land Rover, car2go, FCA, Hyundai, MIT, Audi and Mercedes-Benz will demonstrate how collaboration will make auto the pioneer of the IoT.
Recent progress with Dedicated Short Range Communications (DSRC) Notice of Proposed Rule Making (NPRM) brings connected cars or V2X — connectivity between vehicles, infrastructure and all road users — closer to reality than ever before. If all goes well, an NHTSA mandate on DSRC in new light vehicles is expected to start around 2020 as a phase-in plan, with completion around 2025.
Regulations for aftermarket devices are expected to come soon after. The mandate is expected to leave auto OEMs to choose the applications and human-machine interface (HMI). This will be the culmination of more than a decade of technology development and standardization by U.S. Department of Transportation (USDOT), automotive OEMs and other industry partners.
Significance of V2X. According to USDOT, V2X technology can positively impact more than 80% of non-impaired vehicle crash types that result in over 30,000 deaths in the U.S. alone. A report by the Federal Highway Administration to Congress states that V2X technology is ready to be deployed in the near future and is expected to yield significant safety and efficiency benefits.
From a consumer’s perspective, V2X will be a part of a vehicle ADAS (Active Safety Driver Assistance System). Initial systems will provide information only, and these systems are expected to evolve into warning and control capabilities. In a future vehicle, information from multiple sensors including V2X will be combined/fused to generate a view of the surrounding environment. Figure 1 gives an example of such sensors including long- and short-range radar, lidar, cameras and V2X. V2X offers unique advantages over other sensors that depend on direct line-of-sight. Information can be received from vehicles not visible to other sensors, giving a much larger field of view. V2X can transmit information directly from traffic control devices, instead of inferring information from camera observations.
Figure 1. Example of a vehicle sensor configuration.
Figure 2 depicts the sensor fusion screen from an ADAS development platform by Renesas Electronics America. Such a platform offers the flexibility to implement an ADAS using all available sensors, for example blind-spot warning from radar, forward collision warnings from combined radar, camera and V2X, surround object detection from combined radar, lidar, vision and V2X, with information presented via an OEM-specific HMI.
Figure 2. Renesas ADAS development platform.
GNSS role and challenges
V2X is built on the assumption that vehicles, infrastructure elements, and other road users are location-aware and can communicate critical information to others around them. As seen in Figure 3, the system will position all communicating V2X entities with respect to the host vehicle and security interface, which validates all relevant DSRC messages. A control area network (CAN) or a similar interface will be needed for direct access to vehicle information such as brake and turn-light status and odometer. Interfaces to long-range connectivity such as cellular networks and other data sources such as maps may also be included. The system will connect to an HMI to display information, and future systems will likely evolve to vehicle control functions.
Figure 3. Components of a V2X system.
Looking at the components of an over-the-air (OTA) V2X basic safety message (BSM), this includes a UTC-based time marker, WGS84-based position, and an estimated position error — all critical data that primarily depend on GNSS. RTCM-formatted data may also be sent as optional attachments. A BSM-like personal safety message (PSM) is also defined for pedestrians with V2X-enabled devices.
As per current Minimum Performance Requirements (MPR), a UTC time source with better than 1 millisecond accuracy is required in a V2X device. While almost all current prototypes use GNSS as source of time, others, such as NTP, may also be used. Accurate time reference is a critical prerequisite for basic DSRC functionality. MPR requires time-marked position estimates with 2D and elevation accuracy of 1.5 and 3 meters or better (1 sigma) under open-sky conditions. The automotive industry has opted to define open sky as unobstructed sky view above 5-degree elevation with seven or more satellites visible with HDOP and VDOP limits. The industry expectation is to use this criteria to select GNSS devices that could eventually support lane-level applications (better than 1.5-meter accuracy).
MPR does not put any requirements on the accuracy of the position error estimate in the BSM. It does require that a vehicle stop transmitting BSM whenever the aforementioned time and position accuracy requirements are not met. This implies that a V2X-enabled vehicle may disappear from the V2X view of others in a dense urban canyon or similar environments, leaving at least two questions for system designers from a GNSS perspective alone. First, how to reliably declare that the system cannot meet time and position accuracy requirements, and second, how to deal with the vehicle itself and other V2X entities that may cease to function or broadcast due to GNSS or other limitations. V2X systems are assumed to include inertial and vehicle sensor integration.
Road Ahead. Starting in 2017, connected vehicle pilots (CVP) in New York, Tampa, Florida, and Wyoming will be the next major milestone for V2X. These deployments will be limited to commercial fleets (taxis, public transit, city/road crews and delivery trucks) and some limited road-user categories.
Among the automotive OEMs, Toyota was the first to offer V2X-based driver-assistance technology as ITS Connect in Japan in 2015. General Motors is the first to announce a V2X technology offering in a passenger vehicle in the U.S. with an initial rollout in select 2017 models. The first phase of V2X deployments will only provide driver assistance information while subsequent iterations are expected to bring in safety-focused functions leading to control capabilities.
There is a growing interest in the cellular industry to support V2X-like communication in an upcoming release of the 3GPP standards commonly referenced as 5G. This would enable low latency, peer-to-peer communication with the advantage of an existing device provisioning/authentication infrastructure, something that needs to be built up for DSRC. However, 5G is still a concept, and judging by the lifecycle of LTE, a 5G deployment will take several years to start and several more years to fully deploy while still leaving some rural areas with legacy technology. A framework to manage commercial traffic vs. likely free safety traffic will also be required. These raise the question as to how 5G alone can support vehicle safety applications nationwide.
The FCC has recently proposed a rule to potentially open up the DSRC band for unlicensed Wi-Fi devices, provided Wi-Fi users do not interfere with the primary safety use. Automotive and wireless industry and other stakeholders are investigating the feasibility of possible co-existence in the future. Among the proposed solutions are the rechannelization of DSRC to use a smaller bandwidth and a mechanism for Wi-Fi devices to Detect-and-Vacate the DSRC band when a safety user is detected.
From a technology point of view, V2X has reached a significant milestone with R&D in various technology areas converging and critical standards being adopted recently. With Toyota V2X offering in Japan and GM V2X commitment in the U.S., customers will have V2X as an option this year, further proof that V2X will be on the roads soon. However, significant further work is needed to address the GNSS accuracy and reliability needed for next-generation systems and to address GNSS-specific vulnerabilities such as jamming or spoofing. The New York CVP, which includes deep urban canyons, will probably be a great opportunity for GNSS and V2X communicates to work together on some of these limitations.
The compact FlexPak6 receiver houses NovAtel’s OEM628 triple-frequency plus L-band GNSS receiver board. It tracks all current and future GNSS constellations, with a highly configurable interface designed to meet current and future positioning and integration needs. The FlexPak6 is a GPS and GLONASS receiver that is also Galileo and Compass ready. Upgradable receiver firmware ensures easy updating to future signals. While multi-constellation tracking provides higher solution availability and reliability, its flexible communication interface broadens deployment options. It provides 100-Hz measurements for high dynamic applications. Signals tracked include L1, L2 and L2C and L5. It also has RT-2, ALIGN, GLIDE, RAIM firmware options.
Single- or dual-antenna receiver with latest algorithms
AsteRx-U dual-antenna receiver.
The AsteRx-U receiver incorporates the latest GNSS tracking and positioning algorithms, such as LOCK+ technology to maintain tracking during heavy vibration machine use and IONO+ technology to assure accuracy in regions of elevated ionospheric activity. Interference mitigation counteracts ambient and deliberate RF interference. The AsteRX-U is built around Septentrio’s latest application-specific integrated circuit (ASIC), the GReCo4, and incorporates built-in jamming detection and countermeasures, multipath rejection and fast acquisition. More than 500 hardware channels track all available constellations (GPS, GLONASS, Galileo, Beidou, IRNSS and QZSS).
For applications requiring both RTK and orientation
The Trimble BD935-INS delivers GNSS and inertial technology in an easy-to-integrate form factor for demanding conditions and applications such as lightweight robotic or unmanned vehicles. It features precision GNSS with an integrated 3D micro-electro-mechanical systems (MEMS) inertial sensor package, triple frequency for both GPS and GLONASS constellation, and dual frequency for BeiDou and Galileo. The compact module augments real-time precise positioning with 3D orientation. Connectivity and configuration allow system integrators and OEMs to add GNSS and attitude to specialized or custom hardware solutions. By integrating inertial sensors onto the GNSS module, users receive more robust performance in challenging environments. The module delivers fast and reliable real-time kinematic (RTK) initialization for 1–2 centimeter positioning. The integrated GNSS-inertial engine delivers high-accuracy GNSS and DGNSS positions in challenging environments such as urban canyons, tunnels and heavy canopy.
With its robust 555-channel engine, the new Leica Viva GS16 receiver is empowered by RTKplus to access all known and current signals while intelligently distinguishing which ones are the optimal combination to lock onto for accurate positioning adapting to any environmental conditions. There is also capacity for future signals, such as the full deployment of BeiDou and the expected progress of Galileo and QZSS. Thanks to SmartLink, the precise point-positioning technology, uninterrupted positioning continues even when local corrections services are unavailable due to obstructions or lack of cellular coverage. When no reference data is available, SmartLink continues to enable fully remote work. On a field tablet or controller, users can interact with immersive 3D models directly in the field, ensuring all data is collected and linked to the office.
SurphSLAM combines the new Surphaser 10 laser scanner and GeoSLAM’s new RealTime SLAM registration software. SurphSLAM can be used for extremely accurate high-resolution 3D mobile mapping without the need for GPS. The integration of technologies allows for the resulting point cloud to be registered and displayed in real time, facilitating the performance and speed of the survey. Surphaser scanners produce high-accuracy data sets with ultra-low noise levels. The combination of speed, low range noise, sub-millimeter accuracy and reduced size of the scanner make it suitable for a versatile mobile mapping system such as SurphSLAM. The custom-designed trolley is lightweight and collapsible.
OGC GeoPackage enables platform-independent data exchange
TerraGo Edge 3.9.3 features full support for OGC GeoPackage, a universal format for sharing maps and geographic data across mobile devices and platforms. TerraGo Edge enables users to import and export OGC GeoPackage as a SQLite database optimized for performance on iOS and Android devices. Release 3.9.3 closes the loop for a complete GeoPackage collaboration workflow by allowing Edge app users to import GeoPackage data from a mobile device, collect location-tagged field data, and roundtrip the information back to the GIS or other enterprise systems of record.
Open-source client extended with full galileo support
BNC on a Mac system for static real-time precise point positioning with Google Maps, such as for early warning of natural hazards.
Version 2.12 of the BKG NTRIP Client (BNC) real-time software for Windows, Linux and Mac now comes with complete command line interface and considerable post-processing functionality. RINEX Version 3 file editing and quality check with full support of Galileo, BeiDou and SBAS — besides GPS and GLONASS — are also among the new features. BNC version 2.12 allows simultaneous multi-station precise point positioning (PPP) for real-time displacement monitoring of entire reference station networks. Comparison of satellite orbit/clock files in SP3 format is another new feature, along with a large set of examples for various applications. BNC software was originally developed bythe Federal Agency for Cartography and Geodesy (BKG) and Czech Technical University.
The Leica GMX910 smart antenna is desgined for static, long-term projects requiring a high number of sensors. It can enable dynamic monitoring with up to 10-Hz data streaming and advanced multi-frequency, multi-constellation tracking. Starting with the basic GPS single-frequency receiver and adding multiple upgradable options, the antenna adapts to a wide range of GNSS monitoring applications, from complex manmade to natural structures. The smallest movements of bridges, dams or high-rise buildings are detected in real-time. The antenna supports multiple GNSS satellite systems and signals, tracking up to 555 channels. An IP67 rating against dust and water, extended temperature ranges and low power consumption enables installation of the device in remote areas and severe conditions.
For disaster monitoring, traffic patrol, security monitoring
The 25-gram HX-CH6601A GNSS helix antenna for UAV and geospatial applications receives GPS L1/L2, GLONASS L1/L2 and BeiDou B1/B2. It offers exceptional pattern control, polarization purity and high efficiency in a compact form factor. The antenna is equipped with a high-quality, durable IP65 sealed radome housing and terminated with a subminiature version A (SMA) connector, which has high gain and wide beam width to ensure the signal-receiving performance of satellites at a low-elevation angle.
The pingRX ADS-B (automatic dependent surveillance – broadcast) receiver requires 1/100th the power of conventional ADS-B receivers. It implements sense-and-avoid capabilities for small drones operating in the National Airspace. pingRX measures 32 x 15 x 3 millimeters, which is a fraction of the size of earlier units. It receives ADS-B information broadcast by other aircraft on two frequencies approved by the U.S. Federal Aviation Administration (978 MHz and 1090 MHz.) This allows the unit to detect commercial aircraft threats within a 100-statute-mile radius in real time.
Available as turn-key sUAS or as standalone gimbal
The U1 is a professional-grade unmanned aerial vehicle for the industrial survey and surveillance markets, as well as for cinematographers. Features include redundant flight control and battery systems, customized downlink with two high-definition (HD) video feeds, stability even at full zoom with a gyro-stabilized gimbal system, and remote camera control.
Car & Driver branded dash cam includes built-in GPS
The dash camera CDC-601 is equipped with built-in GPS and motion detection. Media shortcut keys allow the driver to manage settings and view their recordings. The camera automatically records when the driver starts the engine and shuts down when the ignition turns off. The 1080p high-definition camera has a 120-degree wide-angle lens, loop recording, time stamp and accident detection. An 8-GB card is included, but it can support up to a 32-GB card.
A science ROV being retrieved by an oceanographic research vessel.
The Rovins Nano is a new inertial navigation system for the offshore industry. Based on iXBlue’s fiber-optic gyroscope technology, the Rovins Nano is designed for for remotely operated underwater vehicle (ROV) pilots performing maintenance and construction operations. It offers the stability and accuracy of the inertial position, outputting true north, roll, pitch and rotation rates. It can directly transmit the ROV’s position with extreme accuracy because of its integrated INS algorithm capable of collecting acoustic data, regardless of the depth. Rovins Nano adapts itself to the user with easy configuration, installation and use. The goal is for the pilot to forget the existence of the product when maneuvering. Because of its compactness, lightness and open architecture with all third-party sensors, Rovins Nano is easy to integrate into existing ROVs.
New platform optimzed for transportation departments modernizing aging CORS installations
The Septentrio PolaRx5 GNSS receiver.
A new PolaRx5 Continuously Operating Reference Station (CORS) platform has been optimized for state departments of transportation (DOTs) and other real-time-kinematic (RTK) network operators. The PolaRx5 is powered by Septentrio’s AsteRx4 next-generation multi-frequency engine. It offers 544 hardware channels and supports all major satellite signals including GPS, GLONASS, Galileo and BeiDou, as well as regional satellite systems such as QZSS and IRNSS. Septentrio’s Advanced Interference Mitigation (AIM+) technology enables the PolaRx5 to filter out both intentional and unintentional sources of radio interference, from narrowband signals over high-powered pulsed signals to chirp jammers and Iridium transmitters. In addition, Septentrio’s patented APME+ multipath mitigation technology guarantees superior measurement quality by eliminating short-delay multipath errors without introduction of bias. The PolaRx5 leverages Septentrio’s web interface and built-in Wi-Fi and Bluetooth interfaces to give users complete control and visibility of the receiver. The user interface integrates into existing network management systems. The web browser provides secure access to all receiver settings and status, data storage and firmware upgrades as well as a built-in spectrum analyzer for system monitoring.
The Omata One speedometer displays essential information to cyclists in a classic form. The GPS computer inside the speedometer records with high precision so that cyclists can download their activity data to their preferred training applications or websites. On the outside, Omata One has a legible and mechanical analog movement that shows riders the speed, distance, ascent and time. The product displays only these four core pieces of information so the cyclist can focus on the ride. Omata plans to offer additional GPS speedometers for other sports.
Adds LTE, Wi-Fi and cloud-based diagnostics to older cars
Samsung Connect Auto plugs directly into a car’s OBD II port underneath the steering wheel. It uses real-time alerts to help users improve their driving behavior, including increased fuel efficiency, while offering a Wi-Fi connection for passengers. The connection is kept secure using Samsung KNOX , the company’s mobile security platform. The backbone of Samsung Connect Auto is KNOX security and Tizen OS for interoperability. Developers can leverage Tizen and Samsung’s software development kit (SDK) to further evolve additional services. Samsung also encourages safe driving behavior by using geofencing and driver rating algorithms. In the event of an accident, emergency alerts notify the driver’s contacts, and accident concierge services are provided. A “Find My Car” app also helps in locating a car in real time using LTE and GPS. Samsung Connect Auto will initially be available in the second quarter in the U.S., with AT&T the first wireless provider.
Context-dependent scan matching for aided navigation
By Jyh-Ching Juang, Shang-Lin Yu and Shun-Hung Chen
Context-dependent scan matching for aided navigation — finding the rotation and translation that best align two consecutive scans — provides laser-ranging data that can be blended into a GNSS navigation system. A quality index based on analysis of intra-frame point clouds assesses the scan context, accounting for variations in feature richness, to yield a robust aided navigation solution.
For robust and autonomous navigation, many different sensors have been incorporated and, indeed, fused to form a navigation suite that typically includes a GNSS receiver, inertial measurement unit, vision sensor, laser rangefinder, odometer and others. Recently, driven by the goal to achieve autonomous driving, laser range data and image data have been widely adopted in the establishment of vehicle safety and autonomy functions. Laser range data can facilitate navigation and guidance. Through the use of scan matching, vehicle motion can be detected and used in dead reckoning. The surroundings of a vehicle can also be built based on point clouds, so that a feasible path can be generated for obstacle avoidance and vehicle guidance. To some extent, the image data can also be exploited in a similar manner. The use of a visual odometry technique attempts to estimate the relative motion between two consecutive images for dead-reckoning navigation.
This article addresses a limitation in scan matching for vehicular navigation and proposes a context-dependent scheme to account for the variation of the richness of features in scan-matching-based navigation. Environmental context in terms of the richness of features is known to affect the quality of the resulting navigation performance. Thus, in scan matching, we seek to establish a quality index to quantify the quality of the resulting estimates on rotation and translation. In this manner, after fusion with other sensors, a robust positioning solution can be obtained.
Here, we briefly review the scan-matching technique and discuss the aforementioned limitation using a real-world example. We then investigate a context-dependent weighting concept, and the entropy of a scan is used to quantify the richness of its features. We find that a scan with low entropy may be prone to improper registration and an erroneous navigation result. Thus, a weighting is assigned to the scan-matching result for integrated navigation processing. To verify and demonstrate the proposed context-dependent weighting approach, the method is implemented and tested in a vehicle. The result verifies that the proposed scheme can indeed avoid improper registration and lead to robust navigation performance.
Scan Matching
Scan matching is an enabling technique in vehicle navigation, map building and obstacle avoidance, produced by laser ranging devices. Scan matching finds the rotation and translation that best align two consecutive scans. Given two point sets {pn, n = 1,2,K,N} and {qm, m = 1,2,K,M} at two consecutive instants, the scan-matching problem is to determine a correspondence n → m(n) for the registration of two scans and a rotation matrix R and translation (shift) vector s such that the objective function is minimized:
(1)
Once the mapping m(n) is determined, the optimization of (1) can be solved analytically. The determination of the mapping from n to m(n) is typically accomplished by using an iterative method. This class of methods is termed as iterative closest point (ICP), in which the mapping m(n) is determined by searching for the closest point in the target point cloud. There have been many different variations to the ICP by using a different objective function for minimization, a point-to-plane matching, the removal of boundary and/or low-quality correspondences, and so forth. By repeating the scan-matching process, the rotation matrices and translation vectors can be determined and used in the dead-reckoning navigation process to estimate the position and attitude of the vehicle. In robotics and autonomous vehicles, the scan matching is typically integrated with the map-building process for simultaneous localization and mapping (SLAM).
Figure 1 depicts a representative result when the scan-matching technique is used in the SLAM. In the figure, the vehicle moves from the bottom to the top. As the vehicle moves, the laser rangefinder collects measurements for the determination of the vehicle and the mapping of the environment. The location of the vehicle can be estimated (in green) and the environment can be mapped (in blue) by using the scan-matching and filtering techniques. However, as also depicted in the figure, as the vehicle moves to the end of the corridor the point clouds that are obtained from the laser rangefinder (in red) are constrained, and the change of the pose of the vehicle cannot be accurately determined.
Figure 1. Representative SLAM result.
Figure 2 shows the original scans at two consecutive instants (in blue and gray, respectively) and the matched scan after the scan-matching process (in red) when the vehicle moves along the corridor.
Figure 2. Scan-matching result 1.
At this point, the laser rangefinder obtains measurements that are rich in context. The rotation and translation of the vehicle can be estimated with an acceptable level of accuracy, and the vehicle can be located. In this example, the translation vector is found to be s = [11.07 0.50 –0.58]T mm and the minimal error of the objective function is 3.47. When the vehicle moves to the end of the corridor, the scans at two consecutive instants, together with the matched scan, are depicted in Figure 3.
Figure 3. Scan-matching result 2.
In this case, only the end wall is observed by the laser scanner, and the determination of the rotation and translation based on scan matching is subject to errors due to the lack of features. Indeed, by applying the scan-matching technique, the translation vector is found to be s = [9.18 –2.84 13.22]T , which is obviously incorrect in the z axis component. Also, the minimal error of the objective function is 3.20, which is smaller than the error in Figure 2. Thus, the error may not provide a fair assessment of the scan matching due primarily to the fact that the error in registration is not taken into account in the objective function (1). In short, lack of features in the environment may induce improper registration and lead to navigation error.
To account for the aforementioned limitation, several methods can be adopted. One can resort to some variations of the scan-matching techniques by, for example, using feature extraction and matching. Blending with other sensors can be employed. In this case, the vehicle can be equipped with gyros to give information on the change of attitude so that the change of translation can be better estimated. This research project addressed this issue by using a context-dependent weighting to quantify the scan-matching results.
Context-Dependent Weighting
Scan matching attempts to investigate the relationship between two consecutive scans to explore the inter-frame characteristics. However, as discussed, the quality of the scan-matching result depends on the richness of features in the scan, which is revealed by examining the intra-frame characteristic. Given a scan in 2D or 3D, some quality indices can be established to assess its characteristic. For example, principal component analysis (PCA) is a widely applied technique to quantify a scan and to obtain normal vector in a polygon environment. For vehicle navigation in an outdoor environment, the PCA approach may be limited. Here, we propose the use of entropy to assess the complexity of the environment of a scan (or image).
Given a set of K random variables, the entropy is defined as
,(2)
where pk stands for the probability of the k-th random variable. The entropy is a measure that can be used to probe the randomness of a set of random variables. As each probability is bounded by 1, the entropy in (2) ranges between 0 and log2 K.
To assess the entropy of a scan, which is characterized in terms of a combination of angle and range, the scan is converted through a kernel function to become a density-based map. Several different kernel functions can be used. With the density-based scan, the histogram can be formed to obtain an estimate of the probabilities and, consequently, (2) is used to evaluate the entropy.
Figure 4 and Figure 5 represent the original scan and the density-based scan, respectively. The entropy of the sacn in Figure 4 is evaluated to be 1.17. In contrast, the scan in Figure 6 is found to have an entropy of 0.86. Note that Figure 6 is limited in terms of its features, leading to a smaller entropy.
Figure 4. A representative laser range measurement.Figure 5. A density-based scan.Figure 6. Another scan.
By evaluating the entropy of the scan, the scan-matching result can be quantified. A weighting can indeed be assigned as a function of the entropy for integration with other sensors in the integrated navigation system. A limitation of using laser scan data for the assessment of entropy is the need of the conversion to its corresponding density-based map. In vehicular navigation, a camera is often mounted together with a laser rangefinder. As a result, it is possible to use the image data from the camera for the assessment of entropy.
Figure 7 depicts the navigation system design when the context-dependent weighting is used. The navigation suite uses laser rangefinder, camera and other navigation sensors to estimate the position, velocity and attitude of the vehicle. In this approach, the reference scan is matched with the current reading scan based on the scan-matching technique to produce estimates on the rotation and translation. In the meantime, the current scan is overlaid on the image that is obtained from the camera. The region of interest, which is the image that covers the scan points, is extracted. With respect to the region of interest of the image, the entropy is evaluated. The entropy then serves as an indicator in adjusting the weighting of the rotation and translation. The use of image data is the saving in computational complexity. A potential limitation is that the entropy may be sensitive to the variation of gray scale, or RGB values may affect the result.
Figure 7. Integrated navigation with context-dependent weighting.
Experiments
To verify the applicability of the context-dependent weighting, an experiment is conducted. The vehicle is equipped with the following navigation sensors for the determination of position, velocity and attitude.
laser rangefinder
camera
IMU
GPS receiver
odometer
In addition, a GPS real-time kinematic (RTK) receiver provides ground truth. The RTK solution is only used in the evaluation process. Figure 8 depicts the location of the sensors after installation in the test vehicle Luxgen U7.
Figure 8. Test vehicle and the locations of sensors.
The experiment was conducted at a test track of the Automotive Research and Test Center (ARTC), Taiwan, and Figure 9 depicts the track as well as the RTK result. The starting point is at the right upper corner of the track, and the vehicle moves in a counter-clockwise direction.
Figure 9. Test track at ARTC, Taiwan.
The proposed context-dependent weighting approach is evaluated. To assess the significance of the context-dependent weighting, the navigation system processes the laser rangefinder, IMU and encoder data only as these data are obtained from dead-reckoning sensors. More exactly, the GPS receiver data is not used in the processing to better quantify the contrition of the proposed approach. In practice, the GPS receiver data can be used to account for dead-reckoning sensor errors.
Figure 10 depicts the comparison of the estimated trajectory. In the figure, the RTK result is used as a reference, and the dead-reckoning results with and without the context-dependent weighting are shown. Note that when the context-dependent weighting is not used, the estimated trajectory (in red) is subject to two erroneous turns at the lower left corner and upper right corner, respectively.
Figure 10. Estimated trajectories.
The entropy as a function of time is evaluated and shown in Figure 11. Note that the entropies are relatively low at 240 seconds and 1960 seconds, respectively. These two instants correspond to the moments when the vehicle is at the aforementioned corners. Through the use of entropy-based context-dependent weighting in the dead-reckoning process, the navigation error is significantly reduced, as shown in the estimated trajectory (in blue). Thus, the effectiveness of the proposed scheme is verified.
Figure 11. Entropy as a function of time.
Conclusion
For autonomous vehicle applications, knowledge of the current state (such as position, velocity and attitude) of the host vehicle are needed. For robust and autonomous navigation, many different sensors have been incorporated and fused to form a navigation suite. In fusing different sensor data for better accuracy and integrity, the quality of sensors must be considered. We investigated the use of a scan-matching technique for aided navigation. The context of the environment in terms of the richness of features may affect the quality of the resulting navigation system.
To address the context-dependent issue, we used a context-dependent entropy measure to assess the quality in scan matching. In addition to the increments in translation and rotation, the corresponding quality indices are obtained to better blend the scan-matching result into the navigation system. As a result, anomalous navigation results due to lack of features and improper registration can be better dealt with. The proposed scheme is experimentally verified.
Acknowledgments
The work is supported by the joint NCKU-ARTC research project, Taiwan.
JYH-CHING JUANG received a Ph.D. in electrical engineering from the University of Southern California, Los Angeles. He was with Lockheed Aeronautical System Company, Burbank, before joining the faculty of the Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan. His research interests include sensor networks, GNSS signal processing and software-based receivers.
SHANG-LIN YU is an M.S. student in the Department of Electrical Engineering, National Cheng Kung University.
SHUN-HUNG CHEN received a Ph.D. from the Department of Electrical Engineering, National Cheng Kung University. He is with the Electronic Control Technology Group, Research & Development Division, Automotive Research & Testing Center in Taiwan. His research interests include vehicle navigation and autonomous driving.
On May 3, the first LPV-200 approaches were implemented at Paris Charles de Gaulle Airport (LFPG) — the first such approaches to be implemented in Europe. The milestone follows publication of the EGNOS-based procedures on April 28, according to the European GNSS Agency (GSA), which manages EGNOS on behalf of the European Commission.
LPV-200 enables aircraft approach procedures that are operationally equivalent to a CAT I instrument landing system (ILS) procedures. This allows for lateral and angular vertical guidance during the Final Approach Segment (FAS) without requiring visual contact with the ground until a Decision Height (DH) down to only 200 feet above the runway (LPV minima as low as 200 feet).
The first LPV-200 approach in Europe took place May 3 at Charles de Gaulle Airport.
These EGNOS — European Geostationary Navigation Overlay Service — based approaches are considered ILS look-alike, as the LPV-200 service level is compliant with International Civil Aviation Organization (ICAO) Annex 10 Category I precision approach performance requirements, but without the need for the expensive ground infrastructure required for ILS.
“EGNOS LPV-200 is now the most cost effective and safest solution for airports requiring CAT I approach procedures,” says GSA Executive Director Carlo des Dorides. “The involvement of major aircraft manufacturers confirms that this service is a real added-value for civil aviation setting the basis for a better rationalization of nav-aids in European airports.”
The publication of LPV-200 procedures provides numerous benefits, including:
Reduced delays, diversions and cancellations thanks, to the lower minima, potentially reducing the operational costs for flying to this destination.
Increased continuity of airport operations in case of ILS outage or maintenance.
Enhanced safety levels, as the LPV-200 procedures can serve effectively as a CAT I approach procedures and can also be used as a back-up to ILS based procedures.
Improved efficiency of operations, lowering fuel consumption, CO2 emissions and decreasing aviation’s environmental impact.
The LPV-200 Service provides European Airports with the means to implement the most demanding PBN operations as defined by ICAO,” explained ESSP CEO Thierry Racaud. “We congratulate the efforts of those involved in achieving this important milestone for the European aviation community.”
DSNA, the French Air Navigation Service Provider, pioneered these procedures as an outcome of the work co-financed by the European Union and carried out since the GSA declared the EGNOS LPV-200 service operational on 29 September 2015.
Maurice Georges, DSNA CEO, added, “The new LPV-200 approach procedures now implemented at Paris-CDG aim to demonstrate that the SBAS technology, EGNOS in Europe, is a Category I performance approach solution that is reliable. We are convinced that SBAS is a fundamental technology to modernize our navigation infrastructure. Following this first implementation, LPV-200 approach procedures will be progressively deployed over our IFR runway-ends network.”
The approach was been flown by ATR 42-600, Dassault Falcon 2000 aircraft and Airbus A350, with positive pilot feedback. “The LPV system is much more stable and more reliable in terms of safety, but also more efficient than the ILS approach. It really makes a difference,” remarked Eric Delesalle, ATR Chief Pilot, after the first LPV 200 landing on runway 26L at CDG airport.
“The accuracy and stability of the LPV guidance is really amazing, much better than with ILS. Lowering the LPV minima down to 200ft in Europe is a great improvement enabled by EGNOS, and is very valuable for business aviation operations,” confirmed Jean-Louis Dumas, Dassault Flight Test Pilot.
Future implementation. The GSA expects that by launching the first LPV-200 procedure at such an international hub as Charles de Gaulle, it will pave the way for the publication of additional LPV-200 service level procedures at other European airports. In fact, it is already confirmed that Vienna International (LOWW) is set to be the next airport to publish LPV 200 procedures.
Harris Corporation has introduced a comprehensive solution to increase the safety of drones and other commercial unmanned aircraft systems (UAS) flying at low altitudes in the U.S. The announcement was made during Xponential 2016 being held May 2-5 at the Ernest N. Morial Convention Center in New Orleans.
Harris’ ADS-B Xtend service provides critical surveillance information to help UAS operators and airspace managers to increase safety of their operations by providing them with a real-time view of other aircraft flying at low altitudes under 500 feet.
The ADS-B tower with the Xtend antenna. (Photo: Harris Corp.)
The system supplements the FAA’s existing ADS-B network, which provides precise and reliable satellite-based surveillance for the nation’s air traffic control system. The solution features a networked, dual-band receiver and relay system that can be attached to existing structures or to mobile vehicles for roaming coverage.
ADS-B Xtend expands the benefits of the company’s existing UAS situational awareness tool, Symphony RangeVue, which provides data for higher altitude flight traffic. Symphony RangeVue puts real-time FAA aircraft tracking data, flexible background maps and weather information in the hands of UAS operators through a web-hosted platform so they can make better informed decisions.
Data from networks of ADS-B Xtend relays is fused with all FAA system derived real-time aircraft surveillance data from more than 650 ADS-B ground stations with more than 425 FAA radar systems. This unique combination of local infrastructure and NAS surveillance data makes ADS-B Xtend a comprehensive situational awareness solution for the UAS market.
“Strategically deploying ADS-B Xtend receivers will close gaps in ADS-B coverage, significantly increasing the quality and quantity of data available UAS operators,” said Ed Sayadian, president, Harris Mission Networks. “This will increase surveillance data available to UAS operators and enhance safety and efficiency. ADS-B Xtend is yet another step in our commitment to develop the most comprehensive surveillance airspace data set available.”
AT&T’s Fleet Complete, a North American provider of fleet telematics and mobile workforce technology, has upgraded its browser-based mapping to Google Maps.
Fleet Complete with Google Maps includes the ability to visualize real-time asset locations and deliver pertinent vehicle data such as speed, idle time and start/stop times.
The addition of Google Maps allows businesses to track vehicles, assets and mobile workforce with detailed hybrid satellite/street name views, improved traffic reports, terrain views and a powerful zoom feature, helping users make intelligent location-based decisions and maximize efficiencies.
CMD Flight Solutions has received U.S. Federal Aviation Administration (FAA) approval on its third Collins TDR-94/94D Transponder and GPS pairing, the FreeFlight Systems WAAS 1203C.
CMD Flight Solutions develops, markets and provides FAA-certified modifications to support NextGen avionics mandates and assists service and installation facilities with modification solutions to satisfy FAA-mandated requirements. The company provides Automatic Dependent Surveillance-Broadcast (ADS-B) Out on more than 5,000 business and personal aircraft.
The supplemental type certificate (AML STC) of its ADS-B OUT solution for Part 25 airplanes covers installation of FreeFlight’s 1203C SBAS/GNSS GPS position sensor with Rockwell Collins TDR-94/94D transponders. According to FreeFlight, “The pairing is a cost-effective way to help aircraft owners meet the ADS-B mandate.”
ADS-B OUT compliance is due Jan. 1, 2020, in the United States.The 1203C, a 15-channel GPS sensor, is also an approved position source for NextGen applications such as CPDLC, TAWS/FMS, RNP and others.
Fugro has been awarded a supply arrangement by the Canadian Hydrographic Service (CHS) to provide vessel-based hydrographic survey services. Under the contract, CHS will procure hydrographic surveys as needed, anywhere in Canada, to enhance its capacity for data acquisition and processing in support of its nautical charting program.
Hydrographic survey data from ports, harbors, nearshore and offshore regions will be acquired and processed using Fugro’s vessels, equipment and personnel. The resulting data will be used by CHS to update its nautical charts.
The supply arrangement, together with a supply arrangement for airborne lidar bathymetry (ALB) awarded in 2013, will enable Fugro to support Canada in its plans to implement an integrated multi-platform methodology to hydrographic surveying anywhere in Canada, including the Arctic region.
Fugro provides International Hydrographic Organization (IHO) compliant survey services to numerous governments throughout the world.
Penton’s TU-Automotive has unveiled the agenda and speaker line-up for 
