Vehicle Powertrain Shock Reduction via Shaft Speed Control
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Solution Overview
Problem
Existing methods for reducing contact speed and torque between power transmission members in vehicles fail to effectively manage shocks during acceleration and deceleration, leading to discomfort for operators and passengers due to inadequate timing and control of re-contact events.
Innovation Solution
A method and apparatus that detect the rotational speed of an input shaft, calculate the relative rotational position between the input and output shafts, and adjust the rotational speed of these shafts to minimize contact speed and torque at re-contact, using sensors and control modules to optimize the timing and duration of acceleration or deceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If ignition retard compensation is performed based on throttle opening, then contact speed and torque between power transmission members are reduced, but acceleration performance deteriorates due to inappropriate timing
Solution Approach 1:
The patent changes the control parameter from throttle opening to rotational speed difference between upstream and downstream power transmission members. By detecting the actual rotational speed difference that causes slack variation, the system applies ignition retard compensation only when the rotational speed difference exceeds a predetermined threshold, ensuring both shock reduction and maintained acceleration performance.
2Object-affected harmful factors
If ignition control is based on degree of acceleration/deceleration, then contact speed and torque are reduced during high acceleration events, but control is not activated during normal acceleration with small degree values
Solution Approach 1:
The patent replaces the degree of acceleration/deceleration parameter with rotational speed difference as the control criterion. This allows the system to detect and respond to slack variation conditions across a broader range of operating conditions, including normal acceleration events that were previously undetected, thereby improving both shock reduction effectiveness and control adaptability.
3Object-affected harmful factors
If rotational speed difference between power transmission members is reduced, then shock during re-contact is minimized, but control complexity increases due to need for precise rotational position calculation
Solution Approach 1:
The patent replaces complex mechanical position sensing with calculation based on rotational speed detection. By integrating rotational speed signals to derive rotational position and calculating the difference between upstream and downstream members, the system achieves precise control of re-contact shock without requiring additional complex mechanical sensors or devices.
Data Source
AI summary
A method of reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel. The method includes the steps of detecting an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque, calculating a relative rotational position between the input shaft and an output shaft of the controlled section based on the detected information relating to the rotational speed of the input shaft, and accelerating or decelerating at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the calculated relative rotational position.