Hybrid Vehicle Controller Engine Torque Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hybrid type vehicle driving controllers fail to reliably prevent engine excessive rotating states due to sudden changes in battery voltage and friction coefficients, leading to engine racing and unstable vehicle behavior.
Innovation Solution
The hybrid type vehicle driving controller incorporates engine maximum torque calculation processing to determine plural engine maximum torques and engine limit torque calculation processing to set a minimum engine limit torque, adjusting engine torque requests based on electric generator torque deficiencies, ensuring the engine does not exceed these limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the electric generator rotating speed is suddenly raised to respond to battery voltage reduction, then the electric generator can maintain power output, but the engine racing and excessive rotating state occurs
Solution Approach 1:
The system performs preliminary action by calculating the engine limit torque in advance based on electric generator torque deficiency before the engine excessive rotation occurs. The controller proactively adjusts the engine target torque to prevent the racing condition rather than reacting after the problem arises.
Solution Approach 2:
The system implements feedback control by continuously monitoring battery voltage, electric generator torque output, and comparing actual torque with target torque. The engine target torque is dynamically adjusted based on the feedback from electric generator torque deficiency to maintain stable engine operation.
2Power
If the electric generator torque is reduced due to battery voltage reduction, then the electric generator operates within voltage limits, but the engine torque cannot be restrained and engine racing occurs
Solution Approach 1:
The controller acts as an intermediary by introducing a compensation mechanism. When electric generator torque is reduced due to battery voltage limits, the controller calculates the torque deficiency and compensates by adjusting engine target torque, thereby maintaining overall vehicle torque requirements while preventing engine racing.
Solution Approach 2:
The system changes parameters dynamically by adjusting the engine target torque based on battery voltage conditions. When battery voltage is reduced, the controller modifies the engine torque parameter to compensate for electric generator torque deficiency, ensuring stable operation within voltage constraints.
3Reliability
If conventional excessive rotation preventing controls are implemented, then the engine is partially protected from racing, but the controls fail under sudden battery voltage reduction and friction coefficient changes
Solution Approach 1:
The system implements dynamic control by continuously adapting the engine target torque based on real-time battery voltage and electric generator torque conditions. Unlike fixed threshold controls, this dynamic approach adjusts protection levels according to actual operating conditions, maintaining effectiveness under varying battery voltage and friction coefficients.
Solution Approach 2:
The controller performs preliminary calculation of engine limit torque based on electric generator torque deficiency before excessive rotation occurs. This proactive approach ensures the engine target torque is pre-adjusted to prevent racing under sudden voltage changes and varying friction conditions.
Data Source
AI summary
The invention has an engine maximum torque calculating processor for calculating plural engine maximum torques showing a maximum value of engine torque, and an engine limit torque calculating processor for calculating a minimum value of the respective engine maximum torques as engine limit torque. Because the minimum value of the engine maximum torques is calculated as the engine limit torque, it is possible to reliably prevent the engine from entering an excessive rotating state. Further, because the engine limit torque is calculated on the basis of the minimum value of the engine maximum torques, the engine limit torque can be reliably calculated even when there is an individual difference in the engine, an electric generator, etc. and there are calculation errors further, for example, electric generator target torque and the electric generator maximum torque.