Hybrid EV Gear Shift Torque Coordination to Prevent Sudden Acceleration
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Solution Overview
Problem
Hybrid electric vehicles experience sudden acceleration during gear shifting due to transient loss of torque during deceleration braking, affecting the smoothness of travel and user experience.
Innovation Solution
A method and apparatus for controlling gear shifting in hybrid electric vehicles by coordinating the torque and rotational speed of the integrated starter generator (ISG) and traction motor (TM) through a transmission control unit (TCU), using proportional-integral-derivative (PID) control to maintain torque continuity and synchronize rotational speeds, ensuring smooth gear transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If gear shifting control is delayed until after battery charge/discharge operations complete, then battery management is simplified, but acceleration performance deteriorates due to power delivery delays
Solution Approach 1:
The control apparatus predicts future battery charge/discharge completion timing in advance and uses this prediction to determine gear shifting timing, enabling the transmission to shift gears before the battery operation completes, thus resolving the power delivery delay without complicating battery management
2Speed
If gear shifting is controlled based on predicted battery operation timing, then acceleration performance improves, but control system complexity increases
Solution Approach 1:
The control apparatus continuously monitors actual battery charge/discharge timing and compares it with predicted timing, using this feedback to refine future predictions and adjust gear shifting control, thereby managing complexity through adaptive learning rather than rigid complex control logic
Solution Approach 2:
The system replaces complex real-time coordination mechanisms with a prediction-based control strategy that uses historical data and simple algorithms to anticipate battery operation timing, reducing the need for complex real-time control systems
3Power
If gear shifting occurs during battery charge/discharge operations, then power delivery to wheels improves, but transmission component damage risk increases
Solution Approach 1:
The system predicts battery operation completion timing in advance and schedules gear shifting to occur before this predicted time, ensuring power delivery is maintained while avoiding the high-risk period when the battery operation completes and torque fluctuations occur
Solution Approach 2:
The control apparatus proactively prevents transmission component damage by anticipating the timing of battery operation completion and avoiding gear shifts during this critical period, thereby preemptively eliminating the risk of torque fluctuations causing component damage
Data Source
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AI summary
A control method for gear shifting in a hybrid electric vehicle. The method is applied to a transmission control unit (TCU) (1), and comprises: in response to a received vehicle state sent by a VCU (2) being a braking state or a sliding state, determining a first target torque value; on the basis of the first target torque value, sending, once at an interval of a preset time period and by means of the VCU, a first torque control instruction and a second torque control instruction to a controller first MCU (31) and a controller second MCU (41), respectively; in response to the difference between a received rotational speed of an ISG electric motor (3) that is sent by the VCU and a received rotational speed of a clutch (5) being within a preset speed difference range, sending by means of the VCU a rotational speed control instruction and a gear shift instruction to the controller first MCU and the controller second MCU, respectively; and in response to receiving a TM electric motor (4) gear shifting completion instruction sent by the VCU and on the basis of the first target torque value, sending, once at an interval of a preset time period and by means of the VCU, a third torque control instruction and a fourth torque control instruction to the controller first MCU and the controller second MCU, respectively. Further provided are a control apparatus for gear shifting in a hybrid electric vehicle, and a non-volatile computer-readable storage medium. The control method avoids a lack of torque of a TM electric motor during a gear shifting process, thereby solving the problem of sudden acceleration that may occur in a vehicle during the gear shifting process, ensuring the smoothness of traveling, and optimizing the driving and riding experience of drivers and passengers.