New Concept Sliding Mode Control for AMT

The sliding mode algorithm is used for air fuel ratio control, device control, and other systems because of its high responsiveness and robustness. A special feature is that the disturbance suppression characteristic can be set as needed by changing the gradient of the switching line. However, there has been no research into applying this feature. Taking note of the fact that a servo system with a high compliance can be established by lowering the disturbance suppression characteristic, this algorithm was applied to gearing control in automated manual transmissions. During gear changes, automated manual transmissions require the positioning control of a shift rod, the contact control of a sleeve and synchronizer ring, and revolution synchronizing control of the main shaft and counter-shaft by pressing in the sleeve. By applying the sliding mode algorithm to these controls, robust positioning control not affected by backlash or friction, improved revolution control by stabilizing the sleeve pressing force, and contact control that electrically ensures compliance between the sleeve and synchronizer ring have been achieved. In this way, it is possible to prevent sleeve rebound and stoppage during shifting, as well as breakage of the synchronizer ring thereby realizing gear changes within 350 milliseconds without using the mechanical damper system required in conventional transmissions.