Patent ID: 8188863

Claim:
A method for determining whether an object is positioned on or off a support structure of a mobile structure, the method comprising: comparing a current distance value to a prior distance value and a N number of pre-programmed distance measurements, said prior distance value is a distance measurement from the mobile structure to the object at a first time period, said current distance value a distant measurement from the mobile structure to the object at a second time period, said second time period subsequent to said first time period, N being an integer value greater than 1; setting a value of a direction variable to represent a movement of the mobile structure in a forward or reverse direction based on the comparison of the current distance value to the prior distance value; setting a plurality of trip point values to represent movement of the mobile structure over the N number of pre-programmed distance measurements based on the comparison of the current distance value with the N number of pre-programmed distance measurements; determining an on-off condition for the object based on the direction variable and the plurality of trip point values set.