Search and rescue (SAR) mission always takes place when disasters happen. Disaster could be defined into two categories, namely natural disaster and man-made disaster. Natural disasters normally cover a large area making the SAR mission’s team require an aerial view from airplane. This is because it changes the geographical landscape of the affected areas in huge perimeters. The impact is not only changing the whole landscapes, but it also impacts on residences, commercial buildings, transportations and communication infrastructures. This is always the primary reason of choosing an air vehicle as a first respond for any natural disaster. Meanwhile, made-made disasters occur in small areas relative to natural disaster. Terrorist bombing, structural collapse because of human failures or serious accident are some examples of man-made disaster. In addition, the effect from natural disaster such as earthquake also resulting horrendous structural collapse. The challenges for this rescue operation are focused on the interior of the rubble and entire external extent of the damage often not as primary interest because most victims are trapped inside, under the rubbles. Locating, extracting and rescuing any survivors will become the main goal for any rescue mission. Besides, the mission also deals with a lot of potentially dangerous situation such as further collapse, explosions, hazardous gas leaks and fire. Extreme high temperature from fire or explosions prevent rescuer to go down further into rubbles. Urban search and rescue (USAR) is the term that is being used recently for the rescue operation after man-made disaster. Conventionally, dog has been used to identify location of any potential survivors in the rubble. Again, capabilities of dog rescuer are restricted by certain working temperature, uncertainty of void size and fatigue factor. USAR operation is like race against time where trapped survivors cannot wait any longer. Further collapse or explosion may happen anytime. Therefore, the rescue team should have ideal strategy and tactic in order to maximize numbers of survivors being extract from rubble but also minimise the risk face by rescuer. Hazards is everywhere at disaster site. Human rescuers as well as dog are exposed to danger such as further collapse which would trap them in rubble and resulting an increased number of victims. This kind of situation make USAR uncertain. As a result, hazard identification and situation awareness have to be conducted concurrently with finding survivors. Robotic system, in many ways, have shown its versatility in wide range of applications. For instance, a modern and sophisticated automative assembly plant employ robotic systems in the production line in order to fullfil a specific part assembly task. On the other hand, robotic systems also started to be used as exploration vehicle in unknown world such as deep sea and outer space exploration purposes. In many aspects, the implementation of robotic systems in these applications have a significant impact to the overall process flow of the specific application. Having said that, mobile robots use in many deep sea explorations help scientists to discover the 'underworld' where human cannot explore. Therefore, implementation of robotic system in USAR operation is inevitable. In fact, it has been used in several USAR operation including the 9/11 World Trade Centre tragedy and Fukushima Daiichi Nuclear Power Station. The physical design of mobile robot is one of the main challenges to implement robotic system in USAR operation. The ability to manouver and negotiate with rough terrain is highly essential. In addition, the physical design is also need appropriate sensors in order to sense the environment. Therefore, the overall mechatronic structure must consist a robust platform equipped with sensors and actuators and able to navigate seemlessly on extreme rough terrain as well as perform designated task (e.g., find survivors, clean debris or conduct onsite disaster assessment). In order for a mobile robot to operate in unknown world such as USAR environment, it is crucially important for the mobile robot to have certain level of autonomy to plan a desired behaviour and act according to the surrounding. Eventhough it is very challenging to program a mobile robot for this type of environment, a comprehensive control architecture provide a systematic overview of the overall programming structure whilst simplifiying the programming procedure. On top of that, the ability of the overall robot system to plan and track its mission is clearly present in the control architecture. Navigation problem, which is one of the common problem in any exploration robot, also can be solved systematically. In general navigation task, a mobile robot is required to move according to the prior designated trajectory, normally in 2-dimension (flat surface). However, a mobile robot that is design for the USAR operation should be able work and navigate in unknown, uncertain and complex environment. This thesis describes the development of a mobile robot system motivated by the shape-shifting or variable geometry tracked vehicle (VGTV) configuration. The mobile robot is designed with expectation to be able to traverse on various types of terrain and enhance stability to prevent tip-over mishap. The practical work is evaluated by experimental trials on prepared terrains such as staircase, ramp and curb. On top of that, the control framework is outlined to set the objectives of the mobile robot system based on the control hierarchy. This set of works is further simulated with the aim to solve navigation problems as well as to determine the mobile robot behaviour when it is required to travel on uneven surface.
