Velocity estimation using EKF for caster odometers — Numerical verification

Abstract

In this paper, velocity estimation method for caster odometers is proposed. Caster odometer is a sensor of travel distance and attitude angle using caster mechanism that has twodegree of rotational freedoms. We calculate velocities of a vehicle utilizing the output measured by caster odometers , however, the caster mechanism has nonlinearity component. To deal with the nonlinearity of the caster mechanism, a velocity is estimated by the extended Kalman filter. It is expected to reduce the effect of noise with higher precision than conventional methods (approximated differentiation, extended Luenberger observer). We confirm the accuracy of the proposed estimation by comparing to the conventional method in numerical simulation.

Estimation of the Speed From the Odometer Readings Using Optimized Curve-Fitting Filter

“…Using Parks-McClellan optimization method, it is possible to obtain even better results [17] [24]. Authors in [21] proposed the usage of extended Kalman filter (EKF), which had better performance than Luenberger observer and conventional differentiation. The usage of the EKF requires additional information from the system (accelerometer or gyroscope readings, error models of the sensors) [22].…”