An inverted pendulum (also called a cart and pole) consists of a thin rod attached at its bottom to a moving cart. Whereas a normal pendulum is stable when hanging downwards, a vertical inverted pendulum is inherently unstable, and must be actively balanced in order to remain upright, typically by moving the cart horizontally as part of a feedback system.
Machine vision is used to track nodes on the perimeter of a geometric shape associated with a body undergoing cyclic loading, the geometric shape defining a target. The movement of the nodes is related to calculate strain through principles of Finite Element Analysis. The calculated strain is used to determine fatigue damage in the body based on an equation and data obtained using strain-controlled test methods. A finite element analysis fatigue gage includes (1) a sensor to capture the total image of the target and to output data representing the total image, (2) a computer program for (a) isolating the perimeter of the target using edging algorithms and the data, (b) tracking the movement of perimeter nodes of the target as the body undergoes deformation and recording the displacement, and (c) manipulating the data on movement of the nodes using (i) nonlinear stress analysis, (ii) finite element analysis, and (iii) material properties and characteristics and an equation based on strain-controlled test methods, and (3) a data display.