Hybrid Gear Shift Map Control for Regeneration and Acceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles face challenges in improving fuel efficiency and comfortable traveling performance due to conflicting requirements of high gear position for driving and low gear position for regeneration, leading to decreased fuel efficiency during regeneration and insufficient acceleration.
Innovation Solution
A gear shift control device with a memory-based gear shift map that includes cooperative and non-cooperative regeneration maps, allowing for adaptive gear shifting based on vehicle operating states to optimize fuel efficiency and acceleration, featuring distinct thresholds for different operating conditions and using a relay clutch for deceleration regeneration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the gear position is held high during driving, then fuel efficiency and noise are improved, but regeneration efficiency degrades
Solution Approach 1:
The patent applies dynamics by switching between different gear shift maps (first map for driving, second map for regeneration) based on the vehicle's operating state. The transmission control unit dynamically selects which map to use, allowing the gear position thresholds to adapt to whether the vehicle is in driving mode or regeneration mode, thereby resolving the contradiction between maintaining high gear for fuel efficiency and low gear for regeneration efficiency
Solution Approach 2:
The patent changes the parameter thresholds for gear shifting by providing different gear shift maps with different threshold values. The first map has higher thresholds suitable for driving, while the second map has lower thresholds optimized for regeneration. By changing which map is active based on operating conditions, the system optimizes both fuel efficiency during driving and regeneration efficiency when decelerating
2Use of energy by moving object
If the gear position is held high, then fuel efficiency is improved, but acceleration performance deteriorates
Solution Approach 1:
The system dynamically switches between gear shift maps based on the accelerator pedal state. When the accelerator is depressed indicating acceleration demand, the control unit selects the second map which allows lower gear positions for better acceleration response. When the accelerator is not used and fuel efficiency is the priority, the first map with higher gear positions is used
Solution Approach 2:
The system uses feedback from the accelerator pedal state to determine which gear shift map to apply. The accelerator pedal signal serves as feedback about driver intent, allowing the control unit to adjust gear shifting behavior accordingly - maintaining high gears for fuel efficiency when acceleration is not requested, and allowing lower gears for responsive acceleration when the pedal is depressed
Data Source
AI summary
A gear shift control device of an automobile includes memory storing a gear shift map that defines, for each of gear shift points, thresholds of the number of revolutions to determine a switching start timing of each of the gear positions, a transmission control unit that performs switching between the gear positions based on the gear shift map, and a regeneration control unit that controls regeneration. The gear shift map includes a non-cooperative regeneration map that defines the thresholds of revolutions lower than the thresholds in a cooperative request map used in cooperative regeneration, and the non-cooperative regeneration map includes a combustion request map that defines the thresholds of low revolutions and is used when an accelerator is not used, and a travel request map that defines the thresholds of relatively higher revolutions and is used when the accelerator is used.