Fire Extinguishing Robot For Large Space Based On Computer Vision

Fire extinguishing robot is an intelligent firefighting equipment integrated with functions of fire identifying, alarming, locating and extinguishing. Different from traditional fire extinguishing system, the fire extinguishing robot is an active fire extinguishing system capable of automatic fire identification and extinguishing at an early stage. It can effectively prevent fire from happening and expanding, therefore protect human lives and properties in big space buildings. Fire extinguishing systems for big space are complicated to design, involving technical fields of sensors, image processing, controlling, precision machinery, hydraulics, etc. Latest technologies in the field of artificial intelligence have been continuingly applied to develop the fire extinguishing robot, which represents great value in research and application. Based on precedent studies, a fire extinguishing robot for big space based on computer vision is proposed in this thesis. Validated with various tests and accordingly modified, the fire extinguishing robot was checked and accepted by China National Fire Equipment Quality Supervision Center. The detailed contents in this thesis are as follows:Firstly, the overall design of fire location and extinguishing system for big space with fire extinguishing robots was proposed according to Chinese National Standard (Auto tracking and targeting jet suppression system, GB25240-2001). The proposed system consisted a central control unit and robotic control units. Alarm signals of fire were picked up by onsite sensors and sent to central control unit, which activated fire extinguishing robots nearby the fire. Meanwhile, images of targeted fire and the water jet were gathered by fire extinguishing robots and processed with algorithms by central control unit for the purpose of water jet targeting, robotic control units was designed to conduct orders from central control unit precisely by controlling fire extinguishing robots’mechanical movements, as well as sending feedback to central control unit.Secondly, fire identifying, locating and extinguishing algorithms were proposed based on computer vision. For fire identifying, narrowband-pass filter was designed according to wavelength characteristics generated by flame. The system was therefore able to extract pixels of possible flame from the background images for fire identifying, which was carried out by consulting flame image dynamics and ruling out interferences. For fire locating, coordinate of target fire was calculated based on monocular image theory and space coordinate conversion, therefore was used to coordinate the fire extinguishing robot. For the water jet to extinguish the target fire, distance errors caused by gravity and the air resistance between water jet landing point and the target fire was corrected by water jet trajectory extraction through image process, water jet landing point identification and its coordinate calculation, and instant control of the the fire extinguishing robot movement to coincide the water jet landing point and the target fire, therefore realized the closed feedback control of fire locating and extinguishing.Finally, the software and hardware of fire location and extinguishing system for big space with fire extinguishing robots, as well as the communication mode and protocol data, were explained in detail. System trials were conducted, and the results of which showed that fire locating was completed within 60s after the fire alarm went off, with distance error less than 0.5 m, and effective extinguishment of standard test fire was conducted within 3 min of water jet ejection. Therefore, the system is of real-time capability and robustness, and meets the demands in firefighting.