# Recovery Motion Analysis for False Ceiling Inspection Robot
## 2 Background
### Using Mobile Robotic Solutions for False Ceiling Inspection  
Using mobile robots for false ceiling inspection is a promising solution for the multiple problems encountered regarding successful false ceiling maintenance [23; 24]. Robots with various designs in terms of locomotion and form factors are capable of performing tasks in the plenum that are difficult or dangerous to reach for humans. Locomotion modes by such robots can be in the form of wheels, tracks or jointed legs. These mobile robots can perform regular inspections within false ceiling plenums when equipped with visual cameras and thus minimise human intervention in the maintenance process. This would directly reduce incidents of human occupational accidents when working at high heights and injuries involving false ceiling elements or human fatigue. Prior to implementation, case studies would be examined of robots made for navigating constrained spaces and in-pipe inspections [25]. [PERSON] et al. [26] reviewed the various types of robots used in the inspection and monitoring of built infrastructure, mostly having unmanned aerial vehicles (UAVs) and drones to conduct the tasks. The drones usually required an open space to navigate and relay information, instead of working in constrained spaces, as in our case. [PERSON] and [PERSON] [27] also noted in their review of inspection robots that there is a trade-off between sensor technologies and locomotion capabilities for this kind of inspection robot. Thus, little work has been conducted on this specific topic of robotic aid for false ceiling inspection. Research papers found on false ceiling inspection robots are mainly centred around other versions of Falcon robots. Other inspection robots gathered in the literature review were not designed for obstacle crossing [28, 29] or had cumbersome equipment such as tethers and excessive points in the design that could cause the robot to become trapped or entangled [30, 31]. Commercial designs for inspection robots in tight spaces such as SuperDroid [32] utilised tracks for robot locomotion. These designs would face the issue of being trapped by the low-height false ceiling support frame when the frame is between the locomotion system, preventing the main body from extracting itself. Moreover, crawler robots made by Uplink Robotics and Technatics use large wheels to avoid this issue but face a problem where they are unable to access short crawlspaces. These robots were not designed for self-righting capabilities. The limitations of these robots and the operation environment, ability of equipment working within the isolated false ceiling, or inspection range would not match the requirements of the task. This shows that using robotic aid for false ceiling inspection is still a potential research area worth exploring. [PERSON] et al. [33] described a duct-cleaning mobile robot using cameras and tethered means to navigate in ducts and a laser system to track the cross-section within the duct. This design had the basic requirements an inspection robot would need for its tasks. However, its large size is not suitable for our use case of an entire false ceiling zone. [PERSON] and [PERSON] [34] detailed a robot built for inspection with a mounted arm end-effector, with a camera separately mounted on the robot's vertical support wheel, built from aluminium profiles. It was controlled remotely with attached cables. This provided a basis on what components and items would be expected of an inspection robot. However, this robot had multiple protrusions and positions whereby it could be caught by the disordered environment within a false ceiling interior, which would be counterproductive for maintenance and inspection work. [PERSON] et al. [35] reviewed the various robots built for in-pipe inspection and other constrained spaces. The review paper investigated findings regarding various locomotion modes, providing insights into their kinematics and behaviour within constrained environments. For our case, we focus on wheeled mobile bases as the means of locomotion.