Hybrid Vehicle Mode Transition Control via Torque and Speed Mapping
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Solution Overview
Problem
Conventional hybrid vehicle control techniques for transitioning between EV and HEV modes are inefficient due to reliance on battery SOC and vehicle speed alone, neglecting other variables that affect engine on/off control and power distribution, leading to suboptimal fuel efficiency and driving performance.
Innovation Solution
A method that determines engine on map and hysteresis map values differently for each drive mode, incorporating average vehicle speed, driver tendency variables, and environmental variables, to manage battery SOC and control mode transitions based on driver torque requisition, thereby improving fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the engine on map value and hysteresis map value are determined based on only battery SOC and vehicle speed, then the control system is simple, but the on/off control of the engine and power distribution between engine and motor is inefficient
Solution Approach 1:
The patent changes the parameters used for determining engine on map value and hysteresis map value from only battery SOC and vehicle speed to include drive mode (determined by average vehicle speed and accelerator position sensor). This parameter expansion allows the system to adapt control strategies to different driving conditions, improving fuel efficiency without significantly increasing system complexity.
2Device complexity
If the engine on map value and hysteresis map value are determined based on only battery SOC and vehicle speed, then the control logic is simple, but the driving performance is suboptimal
Solution Approach 1:
The patent introduces dynamic adaptation by determining drive mode based on average vehicle speed and accelerator position sensor, then using this drive mode to select appropriate engine on map value and hysteresis map value. This dynamic approach allows the control logic to adapt to changing driving conditions, improving driving performance while maintaining reasonable logic complexity.
3Device complexity
If the transition between EV mode and HEV mode is controlled based on fixed engine on map value and hysteresis map value, then the control is straightforward, but the battery SOC cannot be maintained within normal range under varying driving conditions
Solution Approach 1:
The patent changes the control strategy by introducing drive mode as an additional parameter that affects engine on map value and hysteresis map value determination. This allows the system to maintain battery SOC within normal range under varying driving conditions by adapting the transition thresholds to the current drive mode, improving SOC stability without excessive control complexity.
Data Source
AI summary
Disclosed is a technique for controlling transition between an electric vehicle (EV) mode and a hybrid electric vehicle (HEV) mode in a hybrid vehicle. More specifically, the technique includes first determining a drive mode of the hybrid vehicle by monitoring an average vehicle speed and an accelerator position sensor. Next, an engine on map value is determined for entering into the HEV mode and a hysteresis map value is determined for controlling the transition between the EV mode and the HEV mode based on a battery's state-of-charge (SOC), the average vehicle speed, and the drive mode; Based on the above steps, the technique determines whether the hybrid vehicle should transition between the EV mode or the HEV mode based on a driver's requisite torque calculated by monitoring the accelerator position sensor and a gear position sensor and on the determined engine on map value and hysteresis map value.