Temperature-Adaptive Shift Motor Control for Stable Torque
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Solution Overview
Problem
Existing shift-by-wire systems face instability in motor torque due to temperature variations, as the magnetic flux remains constant, leading to either insufficient or excessive torque based on environmental temperature, affecting the shift device's performance.
Innovation Solution
A shift device with a motor, temperature detecting unit, and control unit that adjusts control gains based on detected temperature, allowing for dynamic adjustment of magnetic flux and torque stabilization by modifying the voltage supplied to the motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the magnetic flux is kept constant in the motor, then the torque becomes stable under normal conditions, but the torque becomes insufficient at low temperatures due to increased grease viscosity and excessive at high temperatures due to decreased grease viscosity
Solution Approach 1:
The patent applies dynamics by making the control gain adjustable based on temperature conditions. Instead of using a fixed control gain, the system dynamically changes the control gain value according to the detected temperature, allowing the motor control to adapt to varying grease viscosity conditions across different temperatures.
Solution Approach 2:
The patent changes the control parameter (control gain) based on temperature. By detecting temperature and selecting different control gain values from a map, the system adjusts the motor's magnetic flux characteristics to compensate for temperature-induced changes in grease viscosity, thereby maintaining stable torque across different operating conditions.
2Reliability
If the control system adjusts control gain based on temperature, then torque stability is improved, but device complexity increases due to additional temperature detection and control calculation requirements
Solution Approach 1:
The patent replaces complex mechanical adjustment mechanisms with an electronic control system. Instead of physically adjusting motor parameters through mechanical means, the system uses electronic control gain adjustment based on temperature detection, simplifying the overall system while achieving the desired torque stability.
Solution Approach 2:
The control system performs self-adjustment by automatically detecting temperature and selecting appropriate control gain values without requiring external intervention. The ECU autonomously manages the control parameter adjustment based on temperature conditions, reducing the need for additional complex control mechanisms.
3Productivity
If the control gain is adjusted dynamically based on temperature, then motor performance is optimized, but storage requirements increase for storing temperature-control gain mapping data
Solution Approach 1:
The patent implements a compromise by storing control gain values for specific temperature ranges rather than continuous temperature data. This partial approach provides sufficient performance optimization across temperature ranges while minimizing storage requirements, avoiding the excessive storage demand of storing data for every possible temperature value.
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 stabilizes motor torque across varying temperatures, ensuring consistent performance and preventing excessive movement of the shift switching member, even when the temperature detecting unit fails, while reducing storage requirements for control gain calculations.
Implementation Method 1
a temperature detecting unit configured to detect a temperature of the motor
Implementation Method 2
a control unit configured to adjust a control gain based on the temperature detected by the temperature detecting unit
Data Source
AI summary
A shift device includes: a shift switching member including plural valleys corresponding to shift positions; a driving unit including a motor, the motor including a rotor and a stator, and configured to drive the shift switching member; a temperature detecting unit configured to detect a temperature of the motor; and a control unit configured to adjust a control gain based on the temperature detected by the temperature detecting unit.