Vehicle Shift Control System for Consistent Acceleration Rhythm
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shift control systems for vehicles with automatic transmissions often fail to provide a consistent and comfortable acceleration feeling, particularly when the driver demands high drive power, leading to incongruity in acceleration performance.
Innovation Solution
A shift control system that repeatedly executes upshifts at a predetermined interval, based on stable accelerator pedal position and longitudinal acceleration, to maintain a consistent acceleration rhythm and tone, enhancing the driver's acceleration feeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the accelerator return sensation mode is shifted to when the change amount of the accelerator opening-extent is in a certain range, then the busy shift is controlled, but the drive power gets felt to be lowering and the driver is given a sense of incongruity
Solution Approach 1:
The patent applies dynamics by making the shift control strategy adaptive rather than fixed. The controller dynamically switches between normal shift control and restricted shift control based on real-time detection of driver acceleration demand through longitudinal acceleration sensing. This allows the system to adjust its behavior according to actual driving conditions, ensuring that shift restrictions are only applied when appropriate and not when the driver demands high acceleration.
Solution Approach 2:
The patent implements feedback by using the longitudinal acceleration sensor to continuously monitor the actual acceleration demand of the driver. This feedback information is fed back to the controller, which then determines whether to apply restricted shift control or normal shift control. The feedback mechanism ensures that the shift control strategy aligns with the driver's actual intentions, preventing incongruous acceleration feelings.
2Power
If upshift is executed frequently to improve acceleration performance, then the acceleration feeling is enhanced, but the shift interval becomes irregular and acceleration rhythm is disrupted
Solution Approach 1:
The patent applies periodic action by implementing a predetermined shift interval in the restricted shift control mode. Instead of executing shifts based on variable conditions that disrupt rhythm, the controller performs upshifts at regular, predetermined time intervals. This creates a consistent and predictable acceleration rhythm that the driver can anticipate, while still achieving improved acceleration performance through controlled upshifts.
3Device complexity
If the shift map restricts upshift to every other gear stage, then the busy shift is controlled, but the acceleration performance is reduced when high drive power is demanded
Solution Approach 1:
The patent makes the shift map dynamic by providing two distinct shift maps: a normal shift map that allows consecutive upshifts and a restricted shift map that limits upshifts to every other gear stage. The controller dynamically selects which map to use based on the detected acceleration demand. When high drive power is demanded (as detected by longitudinal acceleration), the normal shift map is used to allow frequent upshifts and maintain acceleration performance. When acceleration demand is low, the restricted shift map is used to control busy shifts.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Execution of different shift maps. When, during acceleration of the vehicle, the accelerator pedal has already been held at a constant position for a predetermined time period, execution of a second shift map/mode starts and is maintained as long as the accelerator pedal is held at said constant position (see flow chart in Fig.5). With the second shift map, upshift is repeatedly executed at a predetermined shift interval. Thereby an acceleration feeling corresponding to the second shift map is achieved. In other words: An acceleration feeling can be improved (see par. [0017]). Dependent claims 2-4 define embodiments of the shift interval, i.e. embodiments of the second shift map: Claim 2: shift interval = constant time. Thereby an acceleration feeling having a constant rhythm can be enacted on the driver (see par. [0018]); Claim 3: shift interval = constant engine speed. Thereby the tone of the engine speed becomes constant for every shift, hence a comfortable sensation of acceleration can be enacted on the drive (see par. [0019], [0086] and Fig.7); Claim 4: shift interval = a plurality of engine speeds. Thereby sound volume of the engine speed gets gradually smaller every shift, hence hence a comfortable sensation of acceleration can be enacted on the drive (see par. [0020], [0094] and Fig.8).