Estimation of angular velocity and acceleration from shaft encoder measurements

An admittance shaping controller for exoskeleton assistance of the lower extremities

“…1a), the angular position of the motor's output shaft is measured by an array of Hall effect sensors with a resolution (gearing considered) of 600 counts per revolution. In order to eliminate quantization noise, angular velocity and acceleration of the shaft are estimated using a model-free Kalman filter (Belanger et al 1998). For a 1.0 Hz sinusoidal motion, the delay in the acceleration estimate is between 4 and 5 time steps, or about 16 • phase.…”

Operational space trajectory tracking control of robot manipulators endowed with a primary controller of synthetic joint velocity

“…A solution adopted in practice is to differentiate numerically the position signal. However, simple numerical differential may be inadequate for low and high speeds [29].…”

“…and Eqs (27)-(29),. it is easy to see that the closedloop system equation(32)is also obtained by substituting the controller equation(57)into the experimental robot model (43).We have implemented the new joint velocity controller (57)-(58) together with filter (15)-(16) with gains…”

Improving dynamic performances of PWM-driven servo-pneumatic systems via a novel pneumatic circuit

“…This particular filter models the acceleration (if only velocity is supposed to be estimated) as being driven by a white noise [25] (later will be considered as the process noise in the Kalman filtering formulation). The overall noise of measurement is also considered as a white noise.…”