# Recovery Motion Analysis for False Ceiling Inspection Robot
## 3 Materials and Methods  
FalconX is a new design of false ceiling inspection robot with a recovery mechanism. The robot design built in real life is shown in Figure 2. The FalconX robot was designed by the authors and is not commercially available. The robot has a forward-facing visual camera and illumination LEDs in front of the robot for lighting up dark, false ceiling spaces during operation. The main changes involve using a reconfigurable base for the robot to actively climb over false ceiling support runners and other low-height obstacles. The robot has a mounted storage shell on top to enable it to roll over and continue moving even when flipped and provision for a compact wireless WiFi visual camera for easier maintenance  
Figure 1: **Left**: Scenario where the tracked version of Falcon gets trapped due to its design, i.e., its inability to move when suspended in the middle section. **Right**: Example of a previous version of Falcon robot getting stuck due to an orientation, obstacle and form factor. and replacement. Rounded wheel caps are used to mitigate scenarios where the robot would be stuck when flipped on its side. The mass of the robot is 576 g. The dimensions of the robot's bounding box are 20 cm in length, 18 cm in width and 9 cm in height. The wheel diameter is 5 cm, while the length of the rotary arm is 8 cm, also seen in Figure 3.  
Thus, the FalconX robot utilises a new wheeled base with rotary arms, with wheels on the ends to enable the robot to circumvent false ceiling support runner grid structures. This enables the robot to avoid scenarios where it becomes stuck due to the spatial constraints within the false ceiling. The robot has zero turning radius, beneficial for navigating within the constrained space in false ceilings. Figure 3: Main dimensions of FalconX robot. Figure 2: FalconX robot: (**a**) top view; (**b**) axonometric view showing key robot parts. The FalconX robot has a front-facing camera and moves along using six wheels. Two of the wheels (one on each side) are connected to rotary arms that rotate around the front set of wheels to pull the robot over obstacles or help in self-righting the robot. The curved top shell reduces the possibility of the robot getting stuck in an upside down position without the proper orientation of rotary wheels to self-right. The design of the FalconX wheel base rotary wheels allows the robot to climb low-height obstacles (less than or equal to the wheel diameter of 5 cm) by rotating the rotary wheels over the obstacle and using them as a pivot to bring the robot over the obstacle, as seen in Figure 4.  
Upon encountering a low-height obstacle, the robot's rotary arms are lifted over the obstacle (Figure 4(1-5)). The rotary arms are then used to pull the main body of the robot over the low-height obstacle (Figure 4(6-9)). Once the robot passes over the obstacle, the rotary arms are returned to the original position (Figure 4(10-12)) and the FalconX robot can continue its inspection tasks. The new model is wider at its base to reduce the probability of toppling when travelling on a flat plane, as seen in Figure 2. Figure 5 shows the first contact points of the robot with the ground plane if toppled from front and back directions. A front bumper wheel on the front edge of the robot enables the robot to roll when it is tilted forwards. The camera holder design also keeps the robot from resting along its front edge but also lets the offset robot's centre of gravity to self-right the robot back to its neutral position. Figure 4: FalconX using its rotary wheels to overcome low-height obstacles. Upon encountering a low-height obstacle, the rotary arms are lifted over the obstacle (**1–5**). The rotary arms are then used to pull the main body of the robot over the low-height obstacle (**6–9**). Once the robot passes over the obstacle, the rotary arms are returned to the original position (**10–12**) and the FalconX robot can continue its inspection tasks.