Task period of the control algorithm in electronically controlled clutches is one ofthe influencing factors on the engagement quality and computation load. The previous studies provide control algorithms in continuous time-domain, but ignore the performance degradation due to discretization. In order to select an appropriate task period on engagement quality, this paper analyzes the friction-involved clutch engagement dynamics in discrete domain. Models of a closed-loop control system are developed. The models consist of the powertrain with a clutch element, the clutch actuator with time delay, the classical control algorithm combining a feedback and feed-forward link, and a zero-order holder of the task period. After discretization by z-transform, the stability is analyzed, thereafter, the maximum permissible task period, which is 0.3s for the studied system, is determined in terms of stability. Furthermore, the dynamic response is tested in a dSPACE real-time environment. The results show that the maximum vehicle jerk increases rapidly when the task period falls into the unstable region, and the friction loss ceaselessly increases due to the failed synchronization. On the other hand, when the task period falls into the stable area, basically, shorter period gains less vehiclejerk, and the friction loss can be almost the same as that of the continuous system.
Task Period Selection for Engagement Control of Automatic Clutches
2018-06-01
830756 byte
Conference paper
Electronic Resource
English
TASK PERIOD SELECTION FOR ENGAGEMENT CONTROL OF AUTOMATIC CLUTCHES
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