Belt Type Mild Hybrid Transmission Control for Shift Shock Reduction
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Solution Overview
Problem
Shift shocks and prolonged shifting times occur in belt type mild hybrid vehicles due to power interruptions and torque imbalances between driving and non-driving shafts during gear shifts, especially during motor assistance and regenerative braking.
Innovation Solution
A transmission control apparatus and method that uses an integrated control unit to collect shifting information, set target torques for the motor generator, and control it to mitigate shift shocks by adjusting torque limits based on shifting, driving, and regenerative braking conditions, thereby optimizing torque distribution between shafts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If power interruption or sleep interval is applied during shifting to synchronize shafts, then shifting can be performed, but a larger shift shock occurs due to momentary load disappearance and speed increase
Solution Approach 1:
The control unit applies preliminary anti-action by detecting shifting information in advance and controlling the motor generator to maintain driving force during the shifting process. This prevents the momentary load disappearance that causes speed increase and shift shock, thereby reducing the harmful effect while enabling shifting operation.
Solution Approach 2:
The motor generator acts as an intermediary between the engine and transmission system during shifting. By controlling the motor generator to maintain driving force, it mediates the torque transmission and prevents direct torque interruption that would cause shaft speed synchronization issues and shift shock.
2Stability of the object's composition
If motor generator maintains motoring during shifting interval, then driving force is maintained, but shift shock becomes larger and shifting completion time increases
Solution Approach 1:
The control unit dynamically adjusts the motor generator torque based on real-time shifting conditions. Rather than maintaining constant motoring, the torque is optimized during the shifting process to prevent excessive shift shock while ensuring driving force stability, thereby resolving the contradiction between force stability and shock reduction.
Solution Approach 2:
The control unit changes the torque parameter of the motor generator according to shifting stage and vehicle operating conditions. By adjusting torque limits and target torque values during shifting, the system maintains driving force stability while minimizing shift shock, preventing the harmful effects of constant torque maintenance.
3Use of energy by moving object
If motor generator performs regenerative braking during shifting, then power generation occurs, but shift shock increases due to power generation torque and shifting completion time increases
Solution Approach 1:
The control unit performs preliminary action by detecting shifting information before the shifting process and preventing regenerative braking operation during the shifting interval. This advance detection and prevention avoid the power generation torque that would cause shift shock, thereby reducing harmful effects while allowing energy recovery during normal operation.
Solution Approach 2:
The control unit applies preliminary anti-action by identifying conditions where regenerative braking would occur during shifting and actively preventing it. This counteracts the potential harmful effect of power generation torque on shift shock before it can occur, ensuring smooth shifting while maintaining energy recovery capabilities during non-shifting periods.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces shift shocks and completion times, improving ride comfort and transmission durability by minimizing speed and torque differences between shafts during gear shifts.
Implementation Method 1
a motor generator and an engine are interworked by a belt and the motor generator compensates for a torque of a driving shaft connected to a transmission
Implementation Method 2
in a regenerative braking interval in which the motor generator is operated in the form of a generator
Data Source
AI summary
A transmission control method for a belt type mild hybrid vehicle includes collecting, by an integrated control unit, shifting information, setting, by the integrated control unit, a target torque of a motor generator in accordance with the shifting information, and controlling, by a motor control unit, the motor generator. In addition, a transmission control apparatus for a belt type mild hybrid vehicle which performs the transmission control method includes a motor generator that is interworked with an engine and a belt, an integrated control unit that collects shifting information and sets a target torque of the motor generator in accordance with the shifting information, and a motor control unit that controls the motor generator in accordance with the target torque set by the integrated control unit.