Improving Incremental Encoder Measurement: Variable Acquisition Window and Quadrature Phase Compensation to Minimize Acquisition Errors

Abstract

Motion control is an important task in several areas, such as robotics where the angular position and speed should be acquired, usually with encoders. For slow angular speeds, an error is introduced spoiling the measurement. In this paper there will be proposed two new methodologies, that when combined allow to increase the precision whereas reducing the error, even on transient velocities. The two methodologies Variable Acquisition Window and a Quadrature Phase Compensation are addressed and combined simultaneously. A real implementation of the proposed algorithms is performed on a real hardware, with a DC motor and a low resolution encoder based on hall effect. The results validate the proposed approach since the errors are reduced compared with the standard Quadrature Encoder Reading.

Comparison of incremental encoder digital signal processing techniques for theinduction motor flux-torque vector control systems

“…Various modifications of methods for identifying the shaft encoder speed based on classical methods of processing quadrature signals are presented in [16,17], [18,19], [20,21], [22], which allow compensating or reducing measurement errors, including those caused by lack of synchronization between output pulses and sampling periods. In [18], a method for error compensation based on the use of a sliding mode observer is proposed.…”