Unmanned Systems Technology 017 | AAC HAMR UAV | Autopilots | Airborne surveillance | Primoco 500 two-stroke | Faro ScanBot UGV | Transponders | Intergeo, CUAV Expo and CUAV Show reports

69 maximum battery life, so that it can perform as many scans as possible, but it also has to be extremely stable with minimal vibration to allow the scanner to operate effectively. It has to be easy to use as well by non-technical professionals such as surveyors. The idea of the ScanBot has been around for several years, and engineers at Faro have been refining the design, technology and control interface using feedback from potential customers. It started out as a remote-controlled platform with the Faro camera mounted on a metre-high, 30 cm diameter column. It then evolved to using a thinner column, but that created instability in the platform and did not give the flexibility needed to use the camera at different heights. The team has therefore designed a scissor lift that is mounted on a commercial autonomous UGV. The scissor design allows for a much larger field of view for the camera than mounting it directly on a column. It can lift the camera up to eye level to provide a scan for virtual reality systems to simulate the view they would see. Achieving the required stability at this height and with low weight has been a major challenge, says Jaoa Santos, software engineer at Faro. The robot also had to be small enough to fit through corridors and similar spaces indoors – another major challenge in providing a stable base for the scanning camera. However, a small platform means having to use small batteries with limited energy storage, so a highly efficient motor is needed. The platform The system is based around a platform developed by Canadian company Clearpath Robotics. This technology has been widely used in autonomous applications and provides a four-hour operational life from the battery system. The four wheels are driven by two motors, one for those on the left and one for the right, and steering is achieved by varying the speed of each motor. That gives enough manoeuvrability to allow the ScanBot to navigate to the exact position required for each scan. The 24 V, 20 Ah lead-acid battery pack drives the ScanBot at up to 2 m/s, although it generally travels at 1 m/s or so for the safety of any people nearby. The aluminium lift is designed and built in-house, and is the same width as the robot, which enabled the lift to be more stable. “We tried scissor lifts from various US companies but the weight of the camera was too high,” says Santos. “It weighs 1.5 kg, and all the lifts vibrated a lot while the ScanBot was navigating. “Designing and building everything [for the lift] in house solved a very big problem,” he says. “It needs to be very stable, but also very light, so we got rid of any additional metal in the lift, for example by changing the way the blades are designed on the sides.” User interface A key element of the ScanBot’s design is to be able to tell the software where the scans were taken in order to build the 3D model. This allows the ScanBot to do the job over several hours, and the registration of the point cloud is automatic via SLAM. “Setting up the robot in different environments is really hard,” says Santos. “We understand basic robotics, but for other people it’s not so simple. That was one of our first challenges this year.” The ScanBot is designed to be autonomous and can be set up via a web interface that is accessible from a phone or PC. The operator uses the interface to control the robot’s movement by finger, steering the ScanBot through the environment and creating a map. When the map is complete they set the points for the robot to scan, press ‘Play’ and the robot navigates to each point and takes a scan from there. Alternatively, the scan points can be set and the ScanBot navigates independently via the SLAM algorithm and the sensors. Safety Another key design requirement is that the navigation of the ScanBot has to be safe enough for industrial environments. To that end it uses two Velodyne industrially certified Lidar sensors, Faro ScanBot UGV | Digest The lift needs to be very stable but light, so we got rid of any additional metal, such as by changing the blades design Unmanned Systems Technology | December/January 2018 The first versions of the ScanBot had the camera mounted directly on a column, but that created instability in the platform