Gearbox Step Determination via Predicted Engine Time
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Solution Overview
Problem
Conventional methods for determining the number of gear steps in a gearbox rely on acceleration measurements, which are not optimal due to variations in engine torque and delayed availability of measurement results, leading to incorrect gear choices and increased fuel consumption.
Innovation Solution
A method that calculates the number of gear steps based on a predicted time period, considering physical and mechanical parameters such as torque, inertia, and running resistance, allowing for real-time adjustment and improved accuracy in gear changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If acceleration measurements are used to determine gear steps, then gear change timing can be obtained, but measurement delays and torque variations lead to incorrect gear choices
Solution Approach 1:
The system calculates a predicted time period for engine speed changes in advance, before actual gear change execution. This predicted time period is used to determine the number of gear steps proactively, rather than reacting to delayed acceleration measurements after the fact.
Solution Approach 2:
The patent replaces the mechanical measurement system (acceleration sensors and thresholds) with a calculation-based system using engine speed, torque, and predicted time period. This substitution eliminates measurement delays and provides continuous, accurate data for gear step determination.
2Ease of operation
If tabulated acceleration threshold values are used, then gear steps can be determined, but extensive calibration is required which is expensive and time-consuming
Solution Approach 1:
The system uses real-time engine parameters (speed, torque) and pre-stored vehicle characteristics (inertia, running resistance) to automatically calculate the predicted time period and determine gear steps. No manual calibration or adjustment of threshold values is needed, as the system self-adjusts based on current operating conditions.
Solution Approach 2:
The patent changes the basis of gear step determination from fixed acceleration thresholds to dynamic predicted time period calculations. By using continuously variable engine parameters (speed, torque) and vehicle characteristics, the system adapts to different driving conditions without requiring recalibration tables.
3Productivity
If multiple single upshifts are performed within a predetermined period, then gear changes can be executed, but fuel consumption increases due to incorrect gear choices
Solution Approach 1:
The system continuously monitors engine speed and torque, calculates the predicted time period for speed changes, and uses this feedback to dynamically adjust the number of gear steps. This closed-loop approach ensures optimal gear selection that prevents unnecessary multiple upshifts and reduces fuel consumption.
Data Source
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AI summary
The present invention relates to a method for determination of numbers of gear steps N for a gearbox in a motor vehicle, which vehicle comprises an engine connected to, in order to drive, said gearbox, said numbers of gear steps N being the number of downshifts or the number of upshifts which said gearbox is respectively adapted to effecting at an upshift point or a downshift point, where a downshift point represents a first engine speed at which said gearbox is adapted to effecting a downshift, an upshift point represents a second engine speed at which said gearbox is adapted to effecting an upshift, and said numbers of gear steps N are determined on the basis of a predicted time period T which is the time which said engine takes to change from a first engine speed ?1 at a first point in time to a second engine speed ?2 at a second point in time. The invention relates also to a system, a motor vehicle, a computer programme and a computer programme product thereof.