Seite - 157 - in Joint Austrian Computer Vision and Robotics Workshop 2020

360°Monitoring forRobotsUsingTime-of-FlightSensors Thomas Maier,Birgit Hasenberger BECOM SystemsGmbH {thomas.maier,birgit.hasenberger}@becom-group.com Abstract. In this paper, we present a system based onmultiple Time-of-Flight (ToF) 3D sensors paired with a central processing hub for integration into robotsormobilemachines. This systemcanproduce a360°viewfromtherobot’sperspectiveandenables tasks ranging from navigation and obstacle avoid- ance tohuman-robot collaboration. 1. Introduction Today’s e-commerce growth and the paradigms of Industry 4.0 in the manufacturing space present new challenges for robotic systems [1]. In order to increase mobility and autonomy of such systems they need to gather and interpret as much informa- tionaspossiblefromtheirsurroundings. Approaches for collision avoidance with 1D time-of-flight sen- sors have been explored [2], the use of several high- resolutionsensorswouldenableapplications likehu- man pose estimation and gesture recognition as well asautomationtaskssuchashandlingofgoods. Close collaborationandadditional functionalitiesaremade possible with the setup proposed in this paper which consists of intrinsic 3D Time-of-Flight sensors that can cover360°arounda robot’s armor chassis. 2.Systemarchitecture Themulti-ToFplatform1 consistsofacentralpro- cessing module based on a NVIDIA Tegra TX2 pro- cessor (the hub) and multiple camera modules that work inparallel (the frontends). Thisplatformarchi- tecture allows for the integration of various sensor and camera types. TheToFsensorfrontendfor theplatformisacom- pact module designed for close-range detection. Ta- ble1summarises the technicaldataandperformance of two frontend variants. The frontend is connected 1https://www.becom-group.com/goto/multi-tof-platform Figure 1. Image of a front-end including descriptions of its components (left)anda ringof four front-ends (right). QVGA VGA frontend frontend Resolution 304pxx240px 640pxx480px Fieldofview 110°x82° 110°x82° Distance range 0.1–1.5m 0.1–2.0m Operating wavelength 850nm 940nm Framerate 40Hz 30Hz Table1.Frontend specifications. to the hub via FPD-Link III, using a cable that also provides thepowersupply. Four frontendscanbear- rangedasa ring toallowa360°coverage. The hub controls the frontends, performs calibra- tion and correction operations on the incoming data, andultimatelycalculatesdepthmapsorpointclouds. The data is transmitted from the hub via a Gigabit Ethernet connection and supports ROS to gather the individual data streams. The following operations areperformedon thehub: 1. Synchronizationand triggering 2. Acquisitionanddepthmapcalculation 3. Corrections (temperature, FPPN, distance off- set, intrinsicandextrinsic) 4. Filtering (spatial and temporal) 5. 3Dpoint cloudcalculation 6. Registrationand transformation 157