Detta examensarbete är en fortsättning på ett tidigare utfört arbete där koncept på en avloppsmonterad råttfälla togs fram. Allteftersom människor i större utsträckning flyttar till städer blir råttor ett större problem. Råttor kan bära med sig sjukdomar och de kan orsaka omfattande skador. Målet med detta arbete har varit att utveckla delsystem till en avloppsmonterad råttfälla. De delsystem som fokus har legat på är mekanismen för att detektera råttor och mekanismen för att avliva råttor. Övriga delar har utvecklats parallellt i ett annat examensarbete. Examensarbetet genomfördes i samarbete med företaget Nomor, som är ett svenskt tjänsteföretag som bland annat sysslar med skadedjursbekämpning. Arbetet delades in i tre huvuddelar: sensormodul, avlivningsanordning, och hissanordning. CAD-modeller och matematiska modeller togs fram för de olika delsystemen. En testrigg och fysiska prototyper byggdes för undersöka de olika delsystemen. Resultatet av arbetet blev en fysisk prototyp som inefattade de tre ovannämnda delsystemen. Vissa komponenter som köptes in visade sig inte fungera som tänkt vilket gjorde att delar av prototypen inte fungerade. / This thesis is a continuation of a previous project where a concept for a mechanical sewer mountedrat-trap was developed.As more and more people are moving into cities, rats are becoming a bigger issue. Rats cancarry diseases and they can cause extensive damage. The goal of this thesis has been to developsubsystems for a mechanical sewer mounted rat-trap. Focus has been on developing the mechanismfor detecting rats and the mechanism for killing rats. The other subsystems have been developed inparallell in another work.The thesis was done in collaboration with the company Nomor, a swedish service company thatworks primarily with pest control.The work was split into three main parts: sensors, killing mechanism, and height adjustmentmechanism. CAD-models and mathematical models were produced for the three subsystems. A testrig and physical prototypes were produced to test the subsystems.The result ended up with a prototype consisting of the three mentioned subsystems. Some of thepurchased components did not work the way we anticipated wich meant some parts of the prototypedid not work

Urbanisation has historically led to issues with property damage and sickness, due to pests such as rats. Traditionally, rats have been exterminated using poison and manually loaded traps. As of late however, more effective and humane means of control have been developed, such as automatic and connected traps. As rats use the sewer system as we use the highway, connecting properties together, it is natural to place traps there. Nomor, a service company that performs pest control among other services, is interested in developing their own automatic mechanical sewer mounted trap for their own specific needs. In this thesis, the fastening mechanism and enclosure for such a trap are developed, with a concept developed in a previous collaboration used as a base. In this concept, a fastening mechanism is used to fasten the trap to the open pipes located in the sewer manholes. Rats passing underneath the trap are executed by the striking of a carbon dioxide driven cylinder. The enclosure surrounds the fastening mechanism and provides an interface between it and the executional unit, which is developed separately. The final prototype, which was made mostly using 3D-printing of PLA parts and some light metalwork, was tested and evaluated using a testing rig made from layered MDF pieces. The rig was constructed with an optimal scenario in mind, with dimensions like those in pipes which Nomor are likely to want to mount the trap in. The main use of the rig was to evaluate the dimensions and fastening abilities of the trap. Tests and analysis of the construction gave that the fastening mechanism and enclosure had potential to meet the requirements from Nomor in a reliable manner, if a more sophisticated method of mounting and a better mechanism for keeping the trap fastened was developed.