earticle

영어

In order to reduce shifting jerks, synchronous shift is needed on transmission with gear ratios. How to achieve synchronous shift has been the difficulty of AMT (Automated Mechanical Transmission) without synchronizer, which is the main emphasis of shift schedule. In this paper, the experimental study on synchronous up-shifting and down-shifting is given by test-bed which consisted of three-phase induction motor and heavy-duty AMT without synchronizer. Based on shift model, the synchronous speed difference is put forward for the synchronous shift strategy. The synchronizing control strategy of up-shifting is proposed on the basis of the braking characteristics of TB (transmission brake). The synchronizing control strategy of down-shifting is given according to the characteristics of the three-phase induction motor. Under the conditions of various synchronous speed differences, the up-shifting experiments and down-shifting experiments are achieved. By comparisons, the best value of synchronous speed difference is discussed in terms of gear-position and working conditions. The results of shifting experiments show that the synchronous shifting strategies for AMT without synchronizer based on three-phase induction can decrease shifting jerks and improve shift qualities.