Multi-Sensor Orientation Tracking for a Façade-Cleaning Robot

Abstract

Glass-façade-cleaning robots are an emerging class of service robots. This kind of cleaning robot is designed to operate on vertical surfaces, for which tracking the position and orientation becomes more challenging. In this article, we have presented a glass-façade-cleaning robot, Mantis v2, who can shift from one window panel to another like any other in the market. Due to the complexity of the panel shifting, we proposed and evaluated different methods for estimating its orientation using different kinds of sensors working together on the Robot Operating System (ROS). For this application, we used an onboard Inertial Measurement Unit (IMU), wheel encoders, a beacon-based system, Time-of-Flight (ToF) range sensors, and an external vision sensor (camera) for angular position estimation of the Mantis v2 robot. The external camera is used to monitor the robot’s operation and to track the coordinates of two colored markers attached along the longitudinal axis of the robot to estimate its orientation angle. ToF lidar sensors are attached on both sides of the robot to detect the window frame. ToF sensors are used for calculating the distance to the window frame; differences between beam readings are used to calculate the orientation angle of the robot. Differential drive wheel encoder data are used to estimate the robot’s heading angle on a 2D façade surface. An integrated heading angle estimation is also provided by using simple fusion techniques, i.e., a complementary filter (CF) and 1D Kalman filter (KF) utilizing the IMU sensor’s raw data. The heading angle information provided by different sensory systems is then evaluated in static and dynamic tests against an off-the-shelf attitude and heading reference system (AHRS). It is observed that ToF sensors work effectively from 0 to 30 degrees, beacons have a delay up to five seconds, and the odometry error increases according to the navigation distance due to slippage and/or sliding on the glass. Among all tested orientation sensors and methods, the vision sensor scheme proved to be better, with an orientation angle error of less than 0.8 degrees for this application. The experimental results demonstrate the efficacy of our proposed techniques in this orientation tracking, which has never applied in this specific application of cleaning robots.

Proper maintenance way for the multifunctional windows

“…A robot was created to distinguish between the shape of window glass and its frame [32]. Another robot can change from one window panel to another by employing a technique that uses multiple types of sensors that are active at the same time on the Robot Operating System to determine its direction [33]. A wall-climbing cleaning device may also recognize a variety of actions, including avoiding obstacles, wallwalking, wall-climbing, turnover, and cleaning modules [34].…”

Bioinspired, multifunctional dual-mode pressure sensors as electronic skin for decoding complex loading processes and human motions

“…For instance, the direction and rate of change in the stimuli are not readily available from the piezoresistive mode, whereas the piezoelectric mode cannotdistinguish the reverse loading fromthe unloading process.Realizing the full potential of the dual-mode sensors hinges on the comprehensive analysis of the measured signals. The motion direction, operating rate, and real-time attitude are required for up-to-date intelligent robotsto adapt and work in the complex, dynamics, and sometimes extreme environments [46]. However, the existing dual-mode sensing modules are not sufficient, and theylack the aforementioned information to do so, thereby limiting their applications in laboratory settings.Thus, it is highly desirable to develop and demonstratea dual-mode pressure sensorwith extended capabilities to capture the missing information (e.g., the direction, rate, and magnitude of dynamic and static stimuli) for future robots and human-machine interfaces.…”

Novel Mobile Mechanism Design for an Obstacle-Overcoming Robot Using Rotating Spokes

“…In particular, IPC EAGLE [11] and SKYPRO [11] have been commercialized and have even some line-ups. Robots attached to glass windows using strong vacuum adsorption pads, such as Gecko inspired robots [14][15][16][17] and Mantis [18][19], have also been studied. In addition, robots using designated rails [20][21] for building maintenance was developed.…”

“…Robots using a large diameter brush, such as IPC EAGLE [11] and SKYPRO [11] use a combination of wheels and a brush to achieve stable obstacle-overcoming ability. Robots using vacuum adsorption pads, such as those in Gecko inspired robots [14][15][16][17], and Mantis [18][19] adopt mechanical link systems, or a mechanism utilizing the deformation of the adsorption plates to overcome obstacles. In addition, BWMR [20] and BFMR [21] used the designated rails installed at a height higher than the obstacle to avoid interference with the obstacle.…”

“…So the applicability of these cleaning robots is restricted by the obstacle height. Another cleaning robot adopted the adsorption pad mechanism [14][15][16][17][18][19][24][25] have a low moving stroke for obstacles because of small displacement of the adsorption pad deformation. Therefore, it can be applied only to buildings with low obstacles, such as glass wall surfaces, and the applicability is substantially influenced by the details of grass wall frame.…”