Vehicle Shift Controller Using Clutch Modulation to Reduce Shift Shock
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Solution Overview
Problem
Existing vehicles experience gear shift shock during gear changes, particularly in transmissions with dog gears, which can be disruptive and uncomfortable for the rider.
Innovation Solution
A vehicle controller that includes a clutch actuator and shift actuator, controlled by processing circuitry, to manage power transmission rates and engage/disengage transmission gear pairs, reducing shock by gradually adjusting power transmission rates during gear shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gear change is executed by moving transmission gears to engaging positions, then gear stage switching is achieved, but shock is generated at the time of engagement
Solution Approach 1:
The clutch is disengaged before the gear change operation to preliminarily separate the power transmission path. This preliminary action reduces the load and inertial forces acting on the transmission gears during engagement, allowing the gear shift to occur with minimal shock. After the gear change is complete, the clutch is re-engaged to resume power transmission.
Solution Approach 2:
The clutch acts as an intermediary element between the engine and the transmission gears. By controlling the clutch engagement and disengagement, the system can temporarily interrupt power transmission during gear changes, thereby reducing the shock that would otherwise occur when transmission gears engage under load.
2Object-affected harmful factors
If clutch power transmission rate is reduced before shift control, then shock is reduced, but power transmission efficiency temporarily decreases
Solution Approach 1:
The clutch power transmission rate is periodically adjusted: reduced before and during gear change to minimize shock, then increased after gear change to restore full power transmission efficiency. This periodic modulation of power transmission allows the system to temporarily accept reduced efficiency in exchange for eliminating harmful shock, then recover full efficiency once the gear change is complete.
Data Source
AI summary
Processing circuitry included in a controller is configured to: when the processing circuitry acquires a shift command by which a first gear stage is shifted to a second gear stage, execute transmission rate reducing control of controlling a clutch actuator such that a power transmission rate is reduced; after the transmission rate reducing control is executed, execute shift control of controlling a shift actuator such that a transmission gear pair corresponding to the first gear stage and engaging structures corresponding to the first gear stage are disengaged from each other, and a transmission gear pair corresponding to the second gear stage and engaging structures corresponding to the second gear stage are engaged with each other; and after the shift control is executed, execute transmission rate increasing control of controlling the clutch actuator such that the power transmission rate is increased.