Automotive Shift Control via Variable Speed and Motor Torque
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Solution Overview
Problem
Conventional automatic transmission systems experience discomfort and efficiency deterioration due to progressive shift changing, which increases motor load and causes abrupt changes in driving force, leading to an uncomfortable riding experience for passengers.
Innovation Solution
A shift change control system that controls the gear ratio by connecting an engine, an electrical rotary machine, and axles via a differential gearbox, using driving force control and shift-changing speed control to manage the power transmission, allowing for smooth and comfortable shifts based on driver inputs and vehicle conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If progressive shift changing is implemented to maintain driving force, then the driving force continuity is improved, but the response speed deteriorates and motor load increases
Solution Approach 1:
The system dynamically adjusts the shift changing speed based on vehicle conditions and driver intentions. The control unit varies the rate of gear ratio change during shift operations, enabling both smooth progressive shifts when comfort is prioritized and rapid shifts when response is needed, thus resolving the contradiction between driving force continuity and response speed.
Solution Approach 2:
The patent changes the parameter of shift changing speed from a fixed value to a variable parameter that can be adjusted based on different operating conditions. By modifying the speed at which the gear ratio changes during shift operations, the system can optimize between maintaining driving force continuity and achieving fast response, depending on the situation.
2Speed
If rapid shift change is implemented to improve response, then the response speed is improved, but the driving force changes abruptly causing discomfort
Solution Approach 1:
The control system dynamically adjusts the shift changing characteristics based on real-time vehicle conditions and driver inputs. When rapid response is required, the system can execute faster shifts while simultaneously adjusting motor torque to compensate for driving force changes, thus improving response speed without causing uncomfortable fluctuations.
Solution Approach 2:
The electrical rotary machine acts as an intermediary that compensates for driving force changes during rapid shift operations. By controlling the motor torque in coordination with the gear ratio changes, the system can achieve fast response while the motor absorbs or supplements torque to maintain smooth power delivery to the wheels.
3Speed
If abrupt motor speed change is implemented to achieve fast shift, then the response speed is improved, but the engine efficiency deteriorates
Solution Approach 1:
The system dynamically controls motor speed changes during shift operations, adjusting the rate and magnitude of speed variation based on vehicle conditions. This enables fast shifts when needed while minimizing unnecessary motor speed changes that would waste energy, thus resolving the contradiction between shift speed and engine efficiency.
Solution Approach 2:
The patent changes the motor speed parameter from abrupt fixed-step changes to continuously adjustable variable changes. By optimizing the motor speed trajectory during shift operations, the system can achieve fast shifts when required while reducing energy losses during normal operating conditions, thereby improving overall engine efficiency.
Data Source
AI summary
An automotive shift change control system and automatic transmission system is provided to give passengers a comfortable feeling of shift changing or of driving. A transmission connects a vehicle-driving engine, an electrical rotary machine, and axles via a differential gearbox, transmits the power of the engine to the axles via the electrical rotary machine during a shift change, and conducts the shift change. The automotive shift change control unit that controls the change gear ratio of the transmission includes a driving force controller to control the driving force of the electrical rotary machine, a shift-changing speed controller to send a driving force command from the electrical rotary machine to the driving force controller, and a target shift-changing speed changeover device to output the target shift-changing speed that becomes a target value of the shift-changing speed controlled by the shift-changing speed controller.