Method and system for controlling a clutchless automatic transmission for a hybrid-propulsion motor vehicle

Abstract

Disclosed is a method for controlling at least one gearbox actuator for a transmission for a hybrid-propulsion motor vehicle comprising a heat engine and at least one electric machine, said transmission comprising at least one dog clutch system comprising dogs secured to a freely rotatable idler gear on a drive shaft and dogs secured to a sliding gear rotatably secured to a primary shaft, the sliding gear being configured to be moved longitudinally along the axis of the drive shaft by the gearbox actuator in order to engage or disengage the dogs. With a view to disengaging the dogs, the methodinvolves calculating an engine torque setpoint (Cm_sp) to cancel the torque at the dog (Cc) by applying the fundamental principle of dynamics to the dogs (6) to be disengaged; transmitting said calculated engine torque setpoint (Cm_sp) to the engine until the torque at the dog reaches a threshold value (CS1), following a first linearly decreasing slope; comparing the torque at the dog (Cc) with the threshold value (CS1); and, when the torque at the dog (Cc) is less than or equal to the threshold value (CS1), controlling the gearbox actuator (8) by sending a position setpoint (P_sp) to triggerthe movement of the sliding gear (7) in order to disengage the dogs (6).

Description

technical field [0001] The present invention relates to the field of developing control strategies for automatic transmissions. [0002] More particularly, the invention relates to a transmission for motor vehicles comprising, on the one hand, an internal combustion engine for propulsion and, on the other hand, at least one electric machine. Such hybrid transmissions typically include two concentric main shafts, each supporting at least one pinion gear engaged down to a lay shaft connected to the wheels of the vehicle. Background technique [0003] The benefit of hybrid transmissions is that they provide two sources of energy, combustion and electricity, to propel the vehicle's drive train. The torque contributions of these two energy sources can be combined in "hybrid" mode or can be in "engine-only" mode (where the electric machine does not provide any torque to the driveline) or in what is known as "electric-only" mode The case where the internal combustion engine does ...

AI Technical Summary

Problems solved by technology

[0009] However, this control method involves a transmission including a clutch and is not suitable for a clutchless hybrid transmission

[0010] This is because there is no mechanical coupling system in this clutchless hybrid transmission

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