Hybrid Car Electronic Control Unit Torque Map Adjustment
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Solution Overview
Problem
In hybrid cars, the transition from charge sustaining (CS) mode to charge depleting (CD) mode results in a significant increase in engine output, leading to a sense of high-rpm idling felt by the driver due to prioritizing electric travel over hybrid travel in CD mode.
Innovation Solution
The electronic control unit adjusts the required output to ensure it exceeds that of the CS mode only by a smaller margin during transitions and sets targets to reduce engine output during CD mode, prioritizing electric travel over hybrid travel, thereby minimizing engine rotation speed and torque increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the required output is set to exceed significantly during transition from CS mode to CD mode to prioritize electric traveling, then electric traveling priority is improved, but engine rotation speed rises causing high-rpm idling sensation
Solution Approach 1:
The patent applies dynamics by making the required output setting adjustable based on traveling mode. The electronic control unit dynamically adjusts the required output differently for electric traveling versus hybrid traveling, allowing optimal performance in each mode without causing harmful effects during transitions.
Solution Approach 2:
The patent changes the parameter of required output based on the traveling mode (CD mode or CS mode). By setting different required output values for electric traveling and hybrid traveling, the system achieves both high electric traveling priority when needed and smooth transitions without high-rpm idling sensation.
2Speed
If the required output increases significantly during mode transition, then acceleration response is improved, but engine output stability deteriorates causing high-rpm idling
Solution Approach 1:
The system dynamically adjusts required output based on current traveling mode. During electric traveling, higher required output provides fast acceleration response, while during hybrid traveling, moderated required output maintains engine stability, preventing high-rpm idling sensation during mode transitions.
Solution Approach 2:
The electronic control unit changes the required output parameter according to the traveling mode. This parameter adaptation allows the system to achieve both fast acceleration response when needed and stable engine operation during hybrid traveling, resolving the contradiction between speed and stability.
Data Source
AI summary
At a time of HV traveling entailing a load operation of an engine in a CD mode, an electronic control unit sets a required torque Tr* by using a map for a CS mode, in which the required torque Tr* is set to be lower than in a map for the CD mode, as at a time of the CS mode. Then, the electronic control unit control the engine and a motor for traveling in accordance with the required torque Tr*. Accordingly, a rise in the required torque Tr* can be suppressed compared to setting of the required torque Tr* using the map for the CD mode and a sense of high-rpm idling attributable to a rise in a rotation speed of the engine can be inhibited from being felt by a driver.