Backlash Compensation in Gear Trains by Means of Open-Loop Modification of the Input Trajectory

This paper presents an approach to reduce the effect of the backlash nonlinearity in systems with relative cyclic motion. A compensation approach is developed to calculate a modified course of input motion for a desired velocity profile in systems with known backlash. The modified input trajectory contains accelerating and decelerating motion features to traverse the backlash area in minimal time. The method was proved with a dc-motor driven gear train. Results show that the output motion delay could be remarkably reduced. The time to overcome the backlash gap depends upon the desired velocity and the amount of backlash introduced to the system. Time savings between 43% and 74% could be measured with the utilized experimental setup. The proposed velocity compensation method is most efficient for low operating speeds and large mounting allowance between gears.