Electro-mechanical Transmission Speed Monitoring and Torque Control
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Solution Overview
Problem
Existing powertrain systems face challenges in preventing damage to components due to excessive input speeds and torque changes, which can lead to mechanical harm and unexpected operation.
Innovation Solution
A method that monitors and compares input speeds and torque changes of internal combustion engines and electric machines to threshold values, reducing input torques when these exceed limits, and implements intervention strategies such as torque shutoff, ramp-down, or selective ramp-down to prevent overspeed conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If input speeds and torque changes are monitored and controlled to prevent excessive values, then mechanical damage to powertrain components is prevented, but system complexity increases due to additional monitoring and control mechanisms
Solution Approach 1:
The control system continuously monitors input speeds of the internal combustion engine and electric machine, compares them against threshold values, and provides feedback control by reducing input torques when thresholds are exceeded. This closed-loop feedback mechanism prevents mechanical damage while maintaining system reliability.
Solution Approach 2:
The system establishes predetermined threshold values for input speeds and torque changes before operation begins. By pre-defining safe operating limits and preparing intervention strategies in advance, the system can respond immediately to dangerous conditions without complex real-time decision-making, thereby preventing mechanical damage while keeping the control logic manageable.
2Reliability
If input torques are reduced when threshold values are exceeded, then component safety is improved, but power output and productivity decrease
Solution Approach 1:
The control system applies partial torque reduction rather than complete shutdown when threshold values are exceeded. By reducing input torques proportionally or selectively based on which component exceeds its threshold, the system maintains sufficient power output for safe operation while preventing mechanical damage, thus balancing component safety with continued productivity.
Data Source
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AI summary
A powertrain includes an electro-mechanical transmission (10) mechanically-operatively coupled to an internal combustion engine (14) and an electric machine (56,72) to selectively transmit mechanical power to an output member (64). Powertrain operation includes monitoring operator inputs, and determining input speeds and changes in input speeds for the internal combustion engine (14) and the electric machine (56,72). The input speeds are compared to threshold input speeds, and the changes in input speeds are compared to threshold changes in input speeds. Input torques of the internal combustion engine (14) and the electric machine (56,72) are reduced when any one of the input speeds and changes in input speeds exceeds the corresponding threshold.