Upshift process control method of three-gear wire control automatic transmission of electric vehicle

Abstract

The invention discloses a upshift process control method of a three-gear wire control automatic transmission of an electric vehicle. The method uses an electric control unit for judging if a first gear is required to be risen to a second gear and the second gear is required to be risen to a third gear through detecting a signal of a D-gear switch, a vehicle speed signal (v) of a vehicle speed sensor and an openness signal (a) of a motor acceleration pedal position sensor, and controls the electrification current of electromagnetic clutches in each upshift process. Taking the rising from the second gear to the third gear as an example, the electric control unit controls the electrification current of a third-gear electromagnetic clutch according to an electrification current function I3b(t)={I3, t is not smaller than 0 and not greater than T delta; kI3+I3(1-k)(t- T delta) / (T23-T delta), t is greater than T delta and not greater than T23} of the third-gear electromagnetic clutch in a fixed control period T23, and controls the electrification current of a second-gear electromagnetic clutch according to an electrification current function I2b(t)={I2, t is not smaller than 0 and not greater than b T delta; 0, t is greater than b T delta and not greater than T23} of the second-gear electromagnetic clutch, so as to realize the upshift process control of the wire control automatic transmission. The upshift process control method not only can prevent the interruption of input power of the motor in the upshift process, but also can prevent the gear shift impact to realize smooth upshift of the wire control automatic transmission.

Description

technical field [0001] The invention relates to a control method of an automatic transmission, more precisely, a control method for an upshift process of a three-speed wire-controlled automatic transmission of an electric vehicle. Background technique [0002] Automatic transmissions are widely used in various vehicles such as automobiles, electric vehicles, and construction machinery. The existing automatic transmissions mainly include hydromechanical automatic transmission (AT), metal belt continuously variable automatic transmission (CVT), mechanical automatic transmission (AMT) and dual clutch automatic transmission (DCT). [0003] The above-mentioned four types of automatic transmissions all adopt electronically controlled hydraulic servo devices to realize the control of the shifting process, which has complex structure, high cost and increased control difficulty and complexity. In particular, the executive mechanism of DCT includes: oil supply mechanism composed of h...

AI Technical Summary

Problems solved by technology

These hydraulic control mechanisms make the overall structure of the transmission complex, high cost and increase the difficulty and complexity of control

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