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CN-121989950-A - Control system and control method for double-motor power splitting and mixing system

CN121989950ACN 121989950 ACN121989950 ACN 121989950ACN-121989950-A

Abstract

The invention relates to a control method and a control system for a dual-motor power split hybrid system, wherein the control method comprises the steps of obtaining current vehicle state information, judging whether a parking start operation or a parking charging operation is executed based on the current vehicle state information, calculating real-time vibration torque applied to an outer gear ring of a planetary gear after the parking start operation or the parking charging operation is executed, calculating dynamic balance torque which is to be output by a driving motor and can balance the real-time vibration torque to lock the outer gear ring of the planetary gear according to the real-time vibration torque, and controlling the driving motor to operate so as to output the dynamic balance torque. Therefore, the invention can utilize the driving motor to apply dynamic balance torque to the outer gear ring of the planetary gear to eliminate real-time vibration torque acting on the outer gear ring to enable the outer gear ring to be in a locking state, thereby greatly reducing noise and jittering of the shrugged vehicle during parking starting and parking charging, and further eliminating the need of applying an additional locking mechanism to the outer gear ring of the planetary gear.

Inventors

  • HONG JIE

Assignees

  • 舍弗勒技术股份两合公司

Dates

Publication Date
20260508
Application Date
20241105

Claims (10)

  1. 1. A control method for a dual-motor power split hybrid system, wherein the dual-motor power split hybrid system comprises an engine (1), a torsional vibration damper (2), a planetary row (3), a generator (5) and a driving motor (6), one end of the torsional vibration damper (2) is connected with the engine (1) via an engine crankshaft (91), the other end is connected with a planet carrier (33) of the planetary row (3) via an input shaft (92), the generator (5) is fixedly connected with a sun gear (31) of the planetary row (3) via a generator shaft (93), and the driving motor (6) is connected with an outer gear ring (34) of the planetary row (3) via an intermediate transmission mechanism, the control method comprising the steps of: Acquiring current vehicle state information; Determining whether to perform a parking start operation of starting the engine (1) by the generator or a parking charging operation of charging the generator (5) by the engine (1) based on the current vehicle state information; -calculating a real-time vibratory torque T 1 applied to the outer teeth (34) of the planetary row (3) after performing the parking start operation or the parking charge operation; Calculating a dynamic balancing torque T 2 to be output by the drive motor (6) based on the real-time vibration torque T 1 , which can balance the real-time vibration torque to put the outer ring gear (34) of the planetary gear set (3) in a locked state, and The driving motor (6) is controlled to operate so that the dynamic balance torque T 2 is output thereto.
  2. 2. The control method for a two-motor power split hybrid system according to claim 1, wherein the dynamic balancing torque T 2 and the real-time vibration torque T 1 satisfy the following relation: T 2 ＝-i*T 1 Wherein i is a transmission ratio of the intermediate transmission mechanism which dynamically couples the outer teeth (34) of the planetary row (3) and the driving motor (6), and the dynamic balance torque T 2 is opposite to the real-time vibration torque T 1 .
  3. 3. The control method for a two-motor power split hybrid system according to claim 2, wherein the intermediate transmission structure includes a synchronizer capable of implementing a plurality of different gear steps, and the gear ratio i of the intermediate transmission structure is different in value at the different gear steps.
  4. 4. The control method for a two-motor power split hybrid system according to claim 1, wherein the step of calculating a real-time vibration torque T 1 applied to an outer ring gear (34) of the planetary row (3) comprises: acquiring a rotational speed v 1 of the engine crankshaft (91) connected to one end of the torsional vibration damper (2) and a rotational speed v 2 of the input shaft (92) connected to the other end of the torsional vibration damper (2); Calculating a relative rotation angle delta theta between the engine crankshaft (91) and the input shaft (92) based on the rotation speed v 1 of the engine crankshaft (91) and the rotation speed v 2 of the input shaft (92), and The real-time vibration torque T 1 applied to the outer teeth (34) of the planetary row (3) is calculated from a relative rotational angle delta theta between the engine crankshaft (91) and the input shaft (92).
  5. 5. The control method for a two-motor power split hybrid system according to claim 4, wherein the real-time vibration torque T 1 applied to the outer ring gear (34) of the planetary row (3) is calculated by the following expression: T 1 ＝i 1 *f*k*Δθ Wherein i 1 is the transmission ratio between the engine crankshaft (91) and the outer gear ring (34) of the planetary row (3), f is a preset correction factor, k is the torsional rigidity of the torsional vibration damper (2), and Δθ is the relative rotation angle between the engine crankshaft (91) and the input shaft (92).
  6. 6. The control method for a two-motor power split hybrid system according to claim 4, wherein a relative rotation angle Δθ between the engine crankshaft (91) and the input shaft (92) is calculated by the following expression: Wherein Δt is a difference between a sampling time of the rotational speed v 1 of the engine crankshaft (91) and a sampling time of the rotational speed v 2 of the input shaft (92).
  7. 7. The control method for a two-motor power split hybrid system according to claim 4, wherein the rotational speed v 1 of the engine crankshaft (91) is sensed in real time by a rotational speed sensor provided on the engine crankshaft (91), and the rotational speed v 2 of the input shaft (92) is sensed in real time by a rotational speed sensor provided on the input shaft (92).
  8. 8. The control method for a two-motor power split hybrid system according to claim 4, wherein the rotational speed v 2 of the input shaft (92) is calculated according to the following expression: v 2 ＝v Electric generator /(1+a) wherein a is the transmission ratio of the planetary gear set (3) and is equal to the ratio of the number of teeth of the outer ring gear (34) to the number of teeth of the sun gear (31), v Electric generator is the rotational speed of the generator (5), and is sensed by a resolver provided at the generator (5).
  9. 9. The control method for a two-motor power split hybrid system as recited in claim 1, wherein said current vehicle state information includes one or more of battery charge, engine information, water temperature, gear state, braking information.
  10. 10. A control system for performing the control method according to any one of claims 1 to 9, the control system comprising: An acquisition device configured to acquire current vehicle state information; A determination device configured to determine whether to perform a parking start operation of starting the engine (1) by the generator (5) or a parking charge operation of charging the generator (5) by the engine (1) based on the current vehicle state information, and A control device configured to: -calculating a real-time vibratory torque T 1 applied to the outer teeth (34) of the planetary row (3) after performing the parking start operation or the parking charge operation; Calculating a dynamic balancing torque T 2 to be output by the drive motor (6) based on the real-time vibration torque T 1 , which can balance the real-time vibration torque to lock the outer ring gear (34) of the planetary gear set (3), and The driving motor (6) is controlled to operate so that the dynamic balance torque T 2 is output thereto.

Description

Control system and control method for double-motor power splitting and mixing system Technical Field The invention relates to the technical field of double-motor power splitting and mixing systems, in particular to a control system and a control method for a double-motor power splitting and mixing system. Background Generally, a two-motor power split hybrid system includes an engine, a torque damper, a planetary row, a generator, a drive motor, and a differential that selectively outputs power to the differential by coupling the engine in series or parallel with the generator and the drive motor to enhance the power output of the overall power drive system. When the vehicle is in the parking start mode and the parking charge mode, if the outer gear ring of the planetary gear lacks a locking mechanism, the outer gear ring of the planetary gear is easily affected by fluctuating torque during torque transmission and cannot be thoroughly locked due to gaps in a transmission chain between the outer gear ring of the planetary gear and a differential, so that knocking and vibration are transmitted to the power transmission mechanism to cause vibration knocking of the power transmission mechanism, and larger vibration and noise of the whole vehicle are caused. However, if a locking mechanism is provided for the outer ring gear of the planetary gear set, this leads to an increase in cost. Moreover, although the locking of the external ring gear by the lock mechanism significantly reduces noise and rattle during the park start mode and the park charge mode, when the vehicle is rapidly accelerated in other drive modes, the lock mechanism must be released first, and this release operation results in a slower power response of the entire hybrid system. Disclosure of Invention In view of the above, the present invention provides an improved control system and control method for a dual-motor power split hybrid system, which can greatly reduce noise and vehicle-towering during parking start and parking charge without additionally providing a locking mechanism for an outer gear ring of a planetary gear row, and simultaneously improve the responsiveness of the entire dual-motor power split hybrid system. According to one aspect of the present invention, there is provided a control method for a two-motor power split hybrid system including an engine, a torsional damper, a planetary row, a generator, and a drive motor, one end of the torsional damper being connected to the engine via an engine crankshaft and the other end being connected to a carrier of the planetary row via an input shaft, the generator being fixedly connected to a sun gear of the planetary row via a generator shaft, the drive motor being connected to an outer gear of the planetary row via an intermediate transmission mechanism, the control method including the steps of acquiring current vehicle state information, determining whether to perform a parking start operation for starting the engine by the generator or a parking charge operation for charging the generator by the engine, calculating a real-time vibration torque T 1 applied to the outer gear of the planetary row after the parking start operation or the parking charge operation is performed, calculating a real-time vibration torque T 1 to be outputted by the drive motor, balancing the real-time vibration torque so that the outer gear of the planetary row can be balanced, and dynamically balancing the torque T3779 to be outputted by the drive motor to be in a locked state. According to a preferred embodiment of the present invention, the dynamic balancing torque T 2 and the real-time vibration torque T 1 satisfy the following relation: T2＝-i*T1 wherein i is a transmission ratio of the intermediate transmission mechanism which dynamically couples the outer gear ring of the planetary row with the driving motor, and the dynamic balance torque T 2 is opposite to the real-time vibration torque T 1. According to a preferred embodiment of the invention, the intermediate transmission structure comprises synchronizers enabling a plurality of different gear steps, the gear ratio i of the intermediate transmission structure being different in value in the different gear steps. According to a preferred embodiment of the present invention, the step of calculating the real-time vibration torque T 1 applied to the outer ring gear of the planetary row includes: Acquiring a rotation speed v 1 of the engine crankshaft connected with one end of the torsional vibration damper and a rotation speed v 2 of the input shaft connected with the other end of the torsional vibration damper; Calculating a relative rotation angle delta theta between the engine crankshaft and the input shaft based on the rotation speed v 1 of the engine crankshaft and the rotation speed v 2 of the input shaft, and The real-time vibration torque T 1 applied to the outer ring gear of the planetary row is calculated from a relative rotational angle Δθ b