Drivetrain Control Adapting to PTO Load via Fluid Pressure
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Solution Overview
Problem
Automatic mechanical transmissions in heavy commercial vehicles face performance degradation due to significant power take off (PTO) loads, which are not accounted for in existing transmission control routines, leading to reduced driving power and undesirable disturbances.
Innovation Solution
A method to continuously determine the torque magnitude of the PTO by sensing fluid pressure from a PTO fluid pump and adjusting drivetrain operation to compensate for the reduced torque available for the output shaft, thereby optimizing gear selection and shifting strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a power take off (PTO) unit is operated to perform auxiliary tasks, then the vehicle can perform additional functions (e.g., hydraulic pumps for mixing or dumping), but the PTO imposes significant load on the engine, reducing the power available for driving the vehicle
Solution Approach 1:
The system continuously monitors PTO load and feeds this information back to the transmission control unit, which then adjusts gear selection and shifting strategies in real-time to optimize power distribution between the PTO and drivetrain
Solution Approach 2:
The transmission control system dynamically adapts gear selection and shifting behavior based on real-time PTO load conditions, changing control parameters to match the current operational state rather than using fixed preprogrammed routines
2Extent of automation
If preprogrammed transmission control routines are used, then the automatic mechanical transmission operates automatically without complex real-time adjustments, but the control routines do not account for PTO loads, leading to performance degradation
Solution Approach 1:
The control system incorporates continuous feedback from PTO load sensors to dynamically adjust transmission control parameters, ensuring reliable performance under varying PTO conditions while maintaining automatic operation
Solution Approach 2:
The system changes transmission control parameters such as gear selection timing and shifting thresholds based on detected PTO load levels, allowing the automatic transmission to adapt its behavior to match current operational requirements
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 improves the comfort and efficiency of automatic transmissions by accounting for PTO loads, ensuring better power distribution and reducing the impact of PTOs on engine torque, leading to enhanced vehicle performance.
Implementation Method 1
determining a torque magnitude indicative of said power take off unit's torque consumption by sensing a fluid pressure produced by a power take off fluid pump
Data Source
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AI summary
Method for adapting a drive train (100, 110) based upon a PTO load. The method includes continually during vehicle driving determining a torque magnitude indicative of said power take off unit's torque consumption by sensing a fluid pressure produced by a power take off fluid pump. The sensed power take off unit torque consumption is continually compared with an output torque produced by a prime mover (100). Using the difference from said output torque expected value and the measured PTO torque consumption, a control unit adjusts transmission shifting (if automatic) of a transmission and / or prime mover control because the PTO (130, 135) will cause the prime mover (100) to lose some of its available torque. Based on the PTO load, the engine control will selected the appropriate prime mover torque production and the transmission control unit (112) will select the appropriate start gear, upshift gears, and downshift gears.