A method of determining the real time state of a machine includes receiving acceleration and angular rate of motion measurements from IMU's mounted on components of a machine. Fusing signals received from the IMU's with separate Kalman filter modules by combining an acceleration measurement and an angular rate of motion measurement from each IMU to estimate an output joint angle for the component on which the IMU is mounted. Estimated and measured values of the output joint angle for each component are combined, a kinematic equation is solved to determine a real time value for at least one of position, velocity, and acceleration of the component at successive timesteps, and the determined real time values are applied to control movement of each component.