Patent ID: 7952470

Claim:
A collision detecting method, comprising: fixing at least three air bags along a periphery of a main body and specifying a start point position x 0 and an end point position x e , wherein the air bags communicate with each other via at least two through holes, so that a pressure transmission between the air bags and delay of the pressure transmission are implemented by said at least two through holes; detecting and recording pressure values at positions x 1 , x 2 and x 3 respectively of the air bags at different time points; judging whether a collision occurs and calculating a collision force according to pressure variations measured at the positions x 1 , x 2 and x 3 on the air bags; wherein when it is judged that a collision has occurred at a collision position x and time point t 0 , time points t 1 , t 2 and t 3 are recorded when detected pressures at the position x 1 , x 2 and x 3 reach a preset pressure, wherein x 1 , x 2 , x 3 and x e respectively represent distances from the start point position x 0 to the positions on the air bags along the air bags in a same clock direction; and using following equations v ( t 1 −t 0 )=min{( x 1 −x ),[ x +( x e −x 1 )]} v ( t 2 −t 0 )=min{( x 2 −x ),[ x +( x e −x 2 )]} v ( t 3 −t 0 )=min{( x 3 −x ),[ x +( x e −x 3 )]} wherein v represents pressure wave speed during the pressure transmission between the air bags and determining v, t 0 and the collision position x, and wherein the function min{ } represents an operation having a minimal value among values within the bracket.