Page 12 - 卫星导航2021年第1-2合期
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El‑Sheimy and Li  Satell Navig             (2021) 2:7                                    Page 2 of 23





            by reducing congestion, accidents, energy consumption,   Compared with industry and construction, the PLAN
            and time consumption (Schönenberger 2019). Te huge   accuracy requirements for autonomous driving are lower.
            social and economic benefts promote the demand for   However, the application scene is much larger and has
            PLAN technology facing the autonomous driving and   more complex changes; also, the cost is more restrictive.
            mass consumer markets.                            Such factors increase the challenge of PLAN in autono-
                                                              mous driving. Te Society of Automotive Engineers
            Classifcation of indoor navigation from market   divides autonomous driving into L0 (no automation), L1
            perspective                                       (driver assistance), L2 (partial automation), L3 (condi-
            PLAN  technology  is  highly  related  to  market  demand.   tional automation, which requires drivers to be ready to
            Table  1 shows the accuracy requirements and costs of   take over when the vehicle has an emergency alert), L4
            several typical indoor PLAN applications.         (high automation, which does not require any user inter-
              In general, for the applications that require higher   vention but is only limited to specifc operational design
            accuracy,  the  facilities  and equipment  costs  are  corre-  domains, such as areas with specifc facilities and High-
            spondingly higher. In many scenarios (e.g., the mass-mar-  Defnition maps (HD maps), and L5 (fully automation)
            ket ones), the minimum equipment installation cost and   (SAE-International  2016). In most situations, autono-
            equipment cost are important factors that limit the scal-  mous  cars  mean  L3 and above.  Tere  is still a certain
            ability of PLAN technology.                       distance from L5 commercial use (Wolcott and Eustice
              Industry and construction require the PLAN accuracy   2014). An important bottleneck is that PLAN technol-
            at the centimeter- or even millimeter-level. For example,   ogy is difcult to meet the requirements in the entire
            the accuracy requirements for machine guidance and   environment.
            deformation analysis are 1–5  cm and 1–5  mm, respec-  Tere are various derivations and defnitions of the
            tively. Te corresponding cost is in the $ 10,000 level   accuracy requirement of autonomous driving. Table  2
            (Schneider 2010).                                 lists several of those derivations and defnitions.


            Table 1  Accuracy requirements and costs of typical indoor PLAN applications
            Application                       Accuracy requirement             Cost
            Industry and construction (Schneider 2010)  Centimeter‑level to millimeter‑level  $ 10,000 level
            Autonomous vehicles (Basnayake et al. 2010;   Decimeter‑level to centimeter‑level  $ 1,000 level to $ 10,000 level
              Levinson and Thrun 2010; NHTSA 2017; Reid
              et al. 2019; Agency 2019; Stephenson 2016;
              Nvidia 2020)
            Indoor mapping (Cadena et al. 2016)  Decimeter‑level to centimeter‑level  $ 1,000 level
            First responder (Rantakokko et al. 2010)  Decimeter‑level in horizontal, foor‑level in height  $ 1,000 level
            Pedestrian applications (Dodge 2013)  Meter‑level in horizontal, foor‑level in height  Use existing consumer devices; infrastruc‑
                                                                                ture deployment cost of $ 10 level per 100
                                                                                 2
                                                                                  m ‑level area
            Cellular emergency (FCC 2015)     80% within 50 m                  Use existing cellular systems


            Table 2  Derivations and defnitions of accuracy requirement for autonomous driving
            Reference                 Analysis of accuracy requirement of autonomous cars
            Research (Basnayake et al. 2010)  Within 5 m, within 1.5 m, and within 1.0 m for which‑road, which‑lane, and where‑in‑lane, respectively, in V2X
                                       applications
            Report (NHTSA 2017)       1.5 m (1 sigma, 68%) tentatively for lane‑level information for safety applications
            Research (Reid et al. 2019)  For passenger vehicles operating, the bounds of lateral and longitudinal position errors are respectively 0.57 m
                                       (95% probability in 0.20 m) and 1.40 m (95% probability in 0.48 m) on freeway roads, and both 0.29 m (95%
                                       probability in 0.10 m) on local streets
            Research (Levinson and Thrun 2010)  Centimeter positioning accuracy with Mean Square Error (MSE) within 10 cm is sufciently accurate for public
                                       roads
            Report (Agency 2019)      The accuracy of autonomous driving to be within 20 cm in horizontal and within 2 m in height
            Research (Stephenson 2016)  Active vehicle control in Advanced Driver Assistance Systems (ADAS) and autonomous driving applications
                                       require an accuracy better than 0.1 m
            Industry (Nvidia 2020)    The goal is centimeter‑level
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