Drivetrain Loss Torque Estimation for Precise Vehicle Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling and regulating the operation of motor vehicle assemblies, such as transmissions, are imprecise due to varying torque losses in structurally identical drivetrains, leading to inefficiencies.
Innovation Solution
A method and control unit that determine a sum of unknown loss torques in the drivetrain by torque balance during a defined operating condition, using known loss torques and drag torque, and apply this sum for precise control and regulation of vehicle assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If empirically determined loss torques stored in the control unit are used for control and regulation, then the control process is simple, but the control precision deteriorates due to tolerance differences in structurally identical drivetrains
Solution Approach 1:
The patent implements feedback by measuring actual torque values from the drivetrain during operation and using these measurements to determine unknown loss torques. The control unit continuously monitors torque from the drive aggregate and transmission, compares it with empirically determined values, and adjusts the control parameters based on the difference. This closed-loop feedback mechanism resolves the contradiction by maintaining control simplicity while achieving high precision through real-time adaptation to individual drivetrain characteristics.
Solution Approach 2:
The patent changes the parameter approach from using fixed empirically determined loss torques to dynamically determining unknown loss torques based on actual measured torque values. By introducing the second sum of unknown loss torques that is calculated from real-time measurements rather than stored empirical data, the system adapts to individual drivetrain variations while maintaining the overall control structure, thus improving precision without significantly increasing complexity.
2Measurement precision
If the second sum of unknown loss torques is determined by torque balance during defined operating conditions, then control precision is improved, but the measurement and calculation complexity increases
Solution Approach 1:
The patent applies preliminary action by determining the second sum of unknown loss torques during specifically defined operating conditions (such as idle running with brake applied) before normal operation begins. This preliminary determination under controlled conditions allows the system to characterize individual drivetrain losses in advance, and then use these characterized values during subsequent normal operation without requiring continuous complex measurements, thus achieving high precision while limiting the complexity to specific predetermined scenarios.
3Device complexity
If only the first sum of known loss torques is used for control, then the control system remains simple, but the regulation accuracy deteriorates due to unaccounted unknown loss torques
Solution Approach 1:
The patent segments the total loss torques into two distinct components: the first sum of known loss torques (determined empirically and stored) and the second sum of unknown loss torques (determined from torque balance measurements). This segmentation allows the control system to maintain simplicity by keeping the known loss torques as fixed values while adding only the necessary unknown loss torque determination during specific operating conditions. The segmented approach enables accurate regulation by accounting for both known and unknown loss components without requiring complete redesign of the control system.
Data Source
AI summary
A method for operating a drivetrain of a motor vehicle is disclosed. The operation of assemblies of the motor vehicle is controlled and/or regulated by taking into account a loss torque of the drivetrain, such that when a defined first operating condition of the motor vehicle is fulfilled, then as a function of a torque of a drive aggregate (1) of the drivetrain, as a function of a drag torque of a transmission (3) of the drivetrain, and as a function of a first sum of known loss torques of the drivetrain, a second sum of the unknown loss torques of the drivetrain is determined. Thereafter, the operation of assemblies of the motor vehicle is controlled and/or regulated taking into account the first sum of the known loss torques and taking into account the second sum of the unknown loss torques.