To　achieve　tactile　detection　on　the　irregular　surface　of　a　robot　link,　a　flexible　annular　sectorial　sensor　with　a　five-layer　structure　was　proposed　that　could　be　wrapped　on　the　surface　of　a　truncated　cone-shaped　link.　The　sensor　was　designed　for　the　detection　of　a　contact　position　when　robots　collide　with　other　objects　during　movement.　The　sensor　obtains　the　coordinates　of　the　contact　position　by　exerting　a　constant　electric　field　on　the　upper　and　lower　conductive　layers.　The　mathematical　model　linking　the　coordinates　of　the　contact　position　and　the　corresponding　electric　potential　on　the　conductive　layer　was　established,　based　on　the　uniqueness　of　the　electric　field.　The　design　of　the　sensor　was　simulated　using　COMSOL　software,　and　the　detection　error　of　the　contact　position　was　discussed.　a　sensor　sample　was　fabricated　and　wrapped　on　the　mechanical　arm.　The　results　of　the　simulations　and　experiments　indicated　that　the　flexible　sensor　performed　very　well　when　wrapped　on　the　robot　link.　©　2018　by　the　authors.