Hybrid Vehicle SOC Control via Road Slope Detection
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Solution Overview
Problem
Hybrid electric vehicles face inefficiencies in energy use and fuel efficiency due to misjudged State of Charge (SOC) control strategies, which are influenced by unpredictable road conditions and vehicle speed variations, leading to wasted regenerative energy and reduced operability.
Innovation Solution
A method and apparatus that utilize a driving information or road information collecting device to detect slope and road type, and a vehicle controller to dynamically adjust SOC thresholds based on real-time traffic and vehicle speed, optimizing charge and discharge modes to enhance energy recovery and fuel efficiency without upgrading electrical equipment or battery capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If battery charge/discharge control is adjusted based on available output and required output only, then control simplicity is maintained, but energy efficiency and operability deteriorate due to misjudged SOC strategies under varying road conditions and vehicle speeds
Solution Approach 1:
The patent applies dynamics by making the SOC control strategy adaptive and variable based on real-time driving conditions. The controller dynamically adjusts charge/discharge control according to detected vehicle speed, road slope, and traffic conditions, transforming the static control approach into a dynamic one that responds to changing environmental factors, thereby resolving the contradiction between control simplicity and energy efficiency
Solution Approach 2:
The patent implements feedback by continuously detecting driving information (vehicle speed, road slope, traffic conditions) and using this information to adjust the SOC control strategy. The controller receives feedback from sensors about current operating conditions and modifies charge/discharge control accordingly, creating a closed-loop system that improves energy efficiency while maintaining manageable complexity through automated adaptation
2Loss of energy
If SOC control is adjusted based on vehicle speed and road slope information, then energy recovery and fuel efficiency are improved, but control system complexity and information processing requirements increase
Solution Approach 1:
The patent applies universality by using a single integrated controller that performs multiple functions: it manages battery charge/discharge control, processes driving information (vehicle speed, road slope), detects traffic conditions, and adjusts SOC strategies accordingly. This multi-functional approach consolidates what would otherwise require separate systems, improving energy recovery efficiency while limiting the increase in overall system complexity
Solution Approach 2:
The control system applies self-service by autonomously adjusting SOC control strategies based on detected driving conditions without requiring manual intervention or complex external coordination. The system uses its own sensors and processors to detect vehicle speed, road slope, and traffic conditions, then automatically modifies charge/discharge control to maximize energy recovery, making the system self-sufficient and reducing the need for additional control infrastructure
3Loss of energy
If regenerative braking is maximized to recover energy, then fuel efficiency improves, but operability deteriorates when battery SOC is high and charge space is deficient
Solution Approach 1:
The patent applies dynamics by making the regenerative braking control adaptive rather than fixed. The controller dynamically adjusts the extent of regenerative braking based on real-time battery SOC levels and detected driving conditions. When SOC is low, regenerative braking is maximized to recover energy; when SOC is high, the system automatically reduces regenerative braking to prevent charge space deficiency, thereby maintaining both energy efficiency and vehicle operability through dynamic adjustment
Solution Approach 2:
The patent applies parameter changes by modifying the charge/discharge control parameters based on battery SOC state and driving conditions. The system changes key parameters such as the target SOC level, charge/discharge current limits, and regenerative braking torque allocation according to the current operating state. This parameter adaptation allows the system to maximize energy recovery when conditions permit while maintaining operability when battery charge space is limited
4Loss of energy
If EV mode is used in uphill or low-speed sections with low battery SOC, then fuel efficiency improves, but operability deteriorates due to limited available motor torque
Solution Approach 1:
The patent applies dynamics by dynamically adjusting the EV mode operating range based on real-time driving conditions and battery SOC levels. The controller continuously monitors vehicle speed, road slope, and SOC, then adaptively determines whether EV mode should be maintained or discontinued. In uphill sections or when acceleration is required, the system dynamically exits EV mode even if SOC is moderate, ensuring operability while minimizing fuel consumption during favorable conditions
Solution Approach 2:
The patent applies parameter changes by modifying the threshold parameters that govern EV mode operation. The system changes key parameters such as the minimum SOC threshold for EV mode, the vehicle speed range for EV operation, and the road slope compensation factors based on detected conditions. This parameter adaptation allows the system to optimize fuel efficiency by extending EV mode operation when conditions permit while maintaining operability by adjusting parameters to exit EV mode when performance requirements cannot be met
Data Source
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AI summary
A method and apparatus for controlling battery state of charge (SOC) in a hybrid electric vehicle are provided to enable the efficient use of energy, the maximization of energy recovery, and the improvement of fuel efficiency and operability without the improvement of capacity and performance of electrical equipment or a main battery in a hybrid electric vehicle. The apparatus includes a collecting device that collects information regarding the slope or the road type and information regarding the vehicle speed. A controller determines charge and discharge modes based on the driving information and determines a charging upper and lower limit SOC based on the road slope or road type information a road section on which the vehicle is traveling and the vehicle speed information in the road section. A charge or discharge command is output based on the charging upper limit SOC and the charging lower limit SOC.