Sequential Gearshift Control for Natural Shift Feel
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Solution Overview
Problem
Conventional motor vehicles with stepped automatic transmissions fail to provide adequate gear change feeling to drivers when the gearshift position is changed, leading to a disconnect between the driver's expected and actual driving experience, and there is a risk of excessive charging or discharging of the accumulator unit during gear shifts.
Innovation Solution
A motor vehicle system that includes a driving force demand setting module, an effective drive point setting module, and a control module to adjust the engine's drive point in response to gearshift position changes, ensuring the driver experiences a natural gear change feeling while preventing excessive accumulator unit charging or discharging by dynamically adjusting the rotation speed and torque output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is driven at an arbitrary drive point regardless of gearshift position changes, then the power transmission efficiency is improved, but the driver experiences inadequate gear change feeling
Solution Approach 1:
The control module dynamically adjusts the engine's drive point parameters (rotation speed and torque) in response to gearshift position changes. When a gearshift position change is detected, the system updates the effective drive point to provide rotational speed changes that simulate traditional gear shift sensations, while still maintaining operation within the efficient drive point range determined by the preset restriction.
2Ease of operation
If the effective drive point is updated with rotation speed changes in response to gearshift position changes, then adequate gear change feeling is provided, but the accumulator unit may be charged or discharged excessively
Solution Approach 1:
The control module continuously monitors the accumulator unit's charge state and uses this feedback to modulate the drive point adjustments. When a gearshift position change occurs, the system updates the effective drive point to provide gear change feeling, but simultaneously adjusts the rotation speed changes based on the accumulator's current state to prevent excessive charging or discharging, thus maintaining energy balance.
3Ease of operation
If the engine rotation speed is changed in response to gearshift position changes, then the driver experiences natural gear change feeling, but the control complexity increases
Solution Approach 1:
The system pre-determines a restriction that defines the relationship between driving force demand and effective drive point within the efficient drive point range. This preliminary setup allows the control module to quickly adjust the drive point in response to gearshift position changes without complex real-time calculations, reducing control complexity while still providing adequate gear change feeling.
Data Source
AI summary
In response to an upshift of a gearshift position SP in a sequential gearshift range, the drive control of the invention once lowers the rotation speed Ne of an engine. This variation in rotation speed of the engine enables the driver to have adequate gear change feeling, which is similar to the familiar gear change feeling in a conventional motor vehicle equipped with a stepped automatic transmission. Namely the drive control of the invention effectively prevents the driver from feeling something is wrong.