Vehicle Transmission Control for Rapid Acceleration Response
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Solution Overview
Problem
Existing vehicle transmission apparatuses are unable to efficiently reduce fuel consumption while traveling and fail to provide rapid vehicle acceleration in response to driver requests, particularly during gradual deceleration operations.
Innovation Solution
A vehicle transmission apparatus with a speed change mechanism and control device that determines an intermediate target shift speed with a smaller speed ratio than the final target shift speed, allowing for quicker transition to an actual traveling state by forming shift speeds sequentially, starting with smaller speed ratios, and includes a configuration to start the engine before forming the intermediate target shift speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the transmission apparatus directly forms the final target shift speed from a neutral state, then the vehicle can achieve the required acceleration performance, but the time delay until torque transmission begins is reduced only marginally
Solution Approach 1:
The control device performs preliminary actions by determining both the intermediate target shift speed and final target shift speed in advance, and by starting the engine before the intermediate target shift speed is formed. This preliminary preparation reduces the time delay when transitioning from a neutral state to an actual traveling state, thereby improving the response speed to acceleration requests.
2Speed
If the engine is kept running continuously to ensure immediate torque availability, then acceleration response is improved, but fuel consumption increases
Solution Approach 1:
The control device starts the engine in advance before forming the intermediate target shift speed, ensuring that the engine is already running and capable of immediate torque transmission when the shift speed formation begins. This eliminates the need for continuous engine operation during neutral states while ensuring rapid acceleration response when needed.
Solution Approach 2:
The control device dynamically adjusts engine operation based on driving conditions. The engine is started in advance only when an acceleration request is detected, rather than running continuously. This dynamic control optimizes fuel consumption by keeping the engine off during neutral states while ensuring immediate availability when acceleration is required.
3Speed
If the transmission apparatus uses a complex control sequence with multiple intermediate shift speeds, then the response speed to acceleration requests is improved, but the device complexity increases
Solution Approach 1:
The control device determines both the intermediate target shift speed and final target shift speed in advance, along with the engagement element operations required to achieve them. This preliminary determination simplifies the control sequence by pre-planning the entire transition process, reducing the complexity of real-time control decisions while maintaining rapid response performance.
Data Source
AI summary
A vehicle transmission apparatus configured such that when transitioning to an actual traveling state by forming one of the shift speeds from a free running state in which a vehicle is in a traveling state and the speed change mechanism is in a neutral state with none of the shift speeds formed, the control device performs a control to determine from the plurality of shift speeds one final target shift speed according to at least a vehicle speed and a driver request, and an intermediate target shift speed with a speed ratio smaller than that of the final target shift speed, and to form the final target shift speed after formation of the intermediate target shift speed.