Hybrid Transmission Engine Starting via Carrier Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles face challenges in improving engine starting responsiveness due to frequent changes in driving modes, which complicates the enhancement of acceleration performance and fuel efficiency.
Innovation Solution
A transmission configuration for hybrid vehicles that includes differential gear devices and torque transfer mechanisms, allowing for controlled engine speed adjustments through motor generators, enabling improved engine starting responsiveness by synchronizing engine speed with the carrier speed during starting, and optimizing power split modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transmission operates in multiple driving modes (EV mode, power split mode, fixed gear mode) to improve fuel consumption and acceleration performance, then fuel efficiency and power performance are improved, but the responsiveness of engine starting deteriorates due to frequent mode changes
Solution Approach 1:
The control method performs preliminary actions by pre-adjusting the carrier speed of the first differential gear device to match the engine's idle rotation speed before engine start-up. This preliminary speed synchronization ensures that when the engine clutch engages, the engine can start immediately without waiting for speed matching, thus resolving the contradiction between multi-mode operation and starting responsiveness
Solution Approach 2:
The system dynamically adjusts the carrier speed of the first differential gear device based on the detected driving mode. In EV mode, the carrier speed is controlled to match engine idle speed in advance, while in other modes normal operation continues. This dynamic adaptation allows the system to maintain fast engine starting responsiveness while still benefiting from multi-mode fuel efficiency optimizations
2Device complexity
If the carrier speed is not adjusted before engine start-up, then the transmission can operate simply in various modes, but the engine starting time is prolonged due to speed synchronization delay
Solution Approach 1:
The control method performs preliminary speed adjustment of the carrier before engine start-up by controlling the motor generator connected to the carrier. This preliminary action reduces the starting time by ensuring speed compatibility is already established, eliminating the need for prolonged speed synchronization during actual engine engagement
Solution Approach 2:
The motor generator acts as an intermediary device to adjust the carrier speed of the first differential gear device. By using this intermediary mechanism, the system can quickly synchronize speeds without complex mechanical adjustments, thus reducing engine starting time while maintaining control simplicity
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
This solution enhances engine starting responsiveness and driving efficiency by reducing the time required for engine synchronization and optimizing power usage, particularly in power split modes, thereby improving overall vehicle performance.
Implementation Method 1
a first motor generator (MG1) connected to a first member of the first differential gear device; a second motor generator (MG2) connected to the third member of the second differential gear device
Data Source
AI summary
Disclosed herein is a vehicle transmission and a method of controlling the starting of the vehicle. The method includes: starting, by a controller, the engine by a starter; adjusting, by the controller, an input shaft speed of a transmission to a predetermined speed range to engage a coupling element of a torque transfer mechanism; and determining, by the controller, after the coupling element of the torque transfer mechanism is engaged, the input shaft speed of the transmission according to the engine speed and driving efficiency of at least two motor generators, in response to a request for engine power.