Manual Transmission Shiftlock Control via Input Shaft Speed Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional manual transmission systems lack intelligent control mechanisms to prevent damage to vehicle components, reduce noise/vibration/harshness, improve fuel economy, and decrease emissions, as they only rely on vehicle speed for shiftlock interventions, neglecting other critical operating parameters.
Innovation Solution
A control system that includes a shaft speed sensor, wheel speed sensors, and a controller to estimate the input shaft speed of the manual transmission system based on output shaft speed and wheel speeds, and command the shiftlock system to restrict undesirable gear ratios when the estimated speed exceeds a threshold for a specific period, indicating potential damage, poor fuel economy, increased noise, or elevated emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional manual transmission systems rely only on vehicle speed for shiftlock interventions, then the system structure remains simple, but component damage occurs due to undesirable gear ratio engagement
Solution Approach 1:
The control system continuously monitors multiple operating parameters (output shaft speed, wheel speeds, estimated input shaft speed) and uses this feedback to dynamically control the shiftlock system. When the estimated input shaft speed exceeds the threshold for a threshold period, the shiftlock restricts engagement of susceptible gear ratios, preventing component damage while maintaining system reliability.
Solution Approach 2:
The controller acts as an intermediary between the sensors (output shaft speed sensor, wheel speed sensors) and the shiftlock system. It processes sensor data, estimates input shaft speed using known parameters of components between the flywheel and wheels, and translates this information into shiftlock control commands, enabling intelligent protection without direct mechanical complexity.
2Reliability
If the shiftlock system restricts gear ratios based on comprehensive operating conditions, then component damage is prevented, but the ease of operation decreases due to reduced driver control
Solution Approach 1:
The system applies preliminary anti-action by proactively restricting engagement of susceptible gear ratios before damage can occur. When the estimated input shaft speed exceeds the threshold for the threshold period, the shiftlock preemptively prevents the driver from engaging gear ratios that would cause component damage, noise, vibration, harshness, fuel economy degradation, or emissions increases.
Solution Approach 2:
The shiftlock control is dynamic rather than static. The system continuously evaluates multiple operating parameters and adjusts gear ratio availability in real-time based on current conditions. This dynamic approach allows the system to protect components when necessary while maintaining full driver control when operating conditions are safe.
3Measurement precision
If the system monitors multiple operating parameters instead of just vehicle speed, then the precision of shiftlock control improves, but the device complexity increases
Solution Approach 1:
The control system achieves multi-functionality by using a single controller to perform multiple tasks: processing data from the output shaft speed sensor, processing data from wheel speed sensors, estimating input shaft speed using known parameters, determining when threshold conditions are met, and controlling the shiftlock system. This universal approach improves measurement precision without proportionally increasing device complexity.
Solution Approach 2:
The system uses existing vehicle components and sensors (output shaft speed sensor, wheel speed sensors, known parameters of components between flywheel and wheels) to provide the intelligence needed for precise shiftlock control. By leveraging already-present system elements, the patent achieves high measurement precision without adding excessive complexity through dedicated new hardware.
Data Source
AI summary
A control system and method for a vehicle manual transmission system comprising a shiftlock system determines a maximum measured wheel speed of a plurality of measured wheel speeds, estimates a speed of an input shaft of the manual transmission system based on a measured output shaft speed, the maximum measured wheel speed, and a set of known parameters of components of the vehicle connected between a flywheel coupled to an output shaft of a torque generating system and the vehicle wheels, and when the estimated input shaft speed of the manual transmission system is greater than a threshold speed for a threshold period, commands the shiftlock system to restrict the engagement of a set of gear ratios of the manual transmission system.