Hybrid Drivetrain Torque Correction via Electric Machine Feedback
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Solution Overview
Problem
Existing methods for controlling motor vehicle drivetrains with hybrid power sources face inaccuracies in determining drive torque due to aging and wear, leading to suboptimal shift processes and quality.
Innovation Solution
A method that uses sensor information to derive drive torque values for the internal combustion engine, detects the operating state of the electric drive machine, and applies correction factors based on precise torque measurements from the electric drive machine to improve shift control, utilizing existing characteristic diagrams without the need for recalibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If drive torque is derived from sensor quantities (air-mass throughput, injected fuel, throttle valve angle), then the control system can operate without additional torque sensors, but the determination accuracy deteriorates due to temperature influences, complex load states, and aging processes
Solution Approach 1:
The electric drive machine serves as an intermediary measurement device. By measuring its torque demand and comparing it with the internally derived drive torque value, the system obtains an indirect but accurate measurement of the internal combustion engine's torque output without requiring direct torque sensors on the engine itself.
Solution Approach 2:
The system continuously compares the drive torque value derived from sensor quantities with the torque demand of the electric drive machine. This feedback mechanism allows for real-time verification and correction of torque determination accuracy, compensating for errors caused by aging and environmental factors.
2Extent of automation
If characteristic diagrams are used for gearshift control, then shift processes can be automated, but shift quality deteriorates over time due to aging and wear phenomena in mountings, gearwheel pairs, and tires
Solution Approach 1:
The system dynamically adjusts the drive torque parameter used in characteristic diagram evaluations by comparing it with actual electric drive machine torque measurements. This parameter correction compensates for changes in vehicle dynamics caused by aging and wear, maintaining shift quality consistency throughout the vehicle's operating life.
3Device complexity
If drive torque values are used directly from sensor derivations, then the control system remains simple, but shift process quality deteriorates due to system-related inaccuracies
Solution Approach 1:
The electric drive machine acts as an intermediary reference device that provides an accurate torque measurement baseline. By comparing the internally derived torque values against this intermediary reference, the system achieves higher shift process quality without fundamentally changing the control system architecture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures precise torque determination and improved shift quality over the vehicle's operating life by correcting drive torque values, enhancing the accuracy and reliability of gearshift processes without additional sensor technology or recalibration.
Implementation Method 1
detecting an operating state of the electric drive machine during operation of the internal combustion engine by using the at least one control device; and checking the drive torque value MV during operation of the motor vehicle in dependence of given conditions by performing the checking based on at least one quantity characterizing the operating state of the electric drive machine
Data Source
AI summary
A method for controlling a drivetrain of a motor vehicle is provided. The drivetrain includes, as components, at least an internal combustion engine, an electric drive machine, a clutch and a transmission that can be connected to drive wheels. A control device initiates gear shifts at the transmission based on a wide variety of sensor signals by using a characteristic diagram. In order to ensure an excellent shift quality over long operating periods, a drive torque value MV of the internal combustion engine, which is determined by the control device, can be checked and if necessary corrected in dependence of given conditions by determining the drive torque value ME of the electric drive machine.