Electric Vehicle Stop Lamp Control via Regenerative Torque Thresholds
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Solution Overview
Problem
Existing stop lamp control devices for electric vehicles with regenerative braking systems struggle to accurately control the turn-on and turn-off of brake lamps in compliance with revised regulations, which depend on deceleration thresholds and vehicle weight, failing to provide sufficient attention to succeeding vehicles.
Innovation Solution
A stop lamp lighting control device that calculates regenerative torque thresholds based on vehicle speed and weight, using curb weight for turn-on and gross vehicle weight for turn-off, to determine when to activate or deactivate the stop lamps, ensuring compliance with regulatory deceleration thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If deceleration threshold control is used for stop lamp activation, then regulatory compliance is achieved, but accurate control fails when vehicle weight varies between curb weight and gross vehicle weight
Solution Approach 1:
The patent converts the deceleration threshold parameter into a regenerative torque threshold parameter through calculation. The calculation unit computes the regenerative torque threshold based on the relationship between deceleration, vehicle weight, and regenerative torque. This parameter transformation allows the stop lamp control to adapt to different vehicle weights (from curb weight to gross vehicle weight) while maintaining accurate threshold control and regulatory compliance.
Solution Approach 2:
The patent introduces regenerative torque as an intermediary parameter between deceleration control and stop lamp activation. Instead of directly using deceleration threshold control, the system uses regenerative torque threshold control as a mediator. The determination unit compares the actual regenerative torque with the calculated regenerative torque threshold to control the stop lamp, thereby indirectly achieving accurate deceleration-based control that adapts to varying vehicle weights.
2Ease of operation
If stop lamp control is based on fixed deceleration thresholds, then simple control logic is maintained, but insufficient attention is provided to succeeding vehicles when vehicle weight varies
Solution Approach 1:
The patent transforms the control parameter from fixed deceleration threshold to calculated regenerative torque threshold. The calculation unit dynamically computes the regenerative torque threshold based on vehicle speed and weight conditions. This parameter change maintains relatively simple control logic in the determination unit (comparing torque values) while significantly improving the reliability of safety attention by adapting to different vehicle weights, ensuring stop lamps activate appropriately whether the vehicle is at curb weight or gross vehicle weight.
3Speed
If regenerative torque threshold is calculated using curb weight, then stop lamp turns on timely, but may turn off too early when vehicle is loaded to gross weight
Solution Approach 1:
The patent performs preliminary calculation of the regenerative torque threshold using curb weight (the lighter condition). This preliminary threshold ensures timely stop lamp activation when the vehicle is empty. The system prepares this threshold in advance through the calculation unit before actual stop lamp control, allowing rapid response while maintaining accuracy for the curb weight condition.
Solution Approach 2:
The patent implements dynamic adjustment of the regenerative torque threshold based on vehicle loading conditions. The calculation unit calculates different regenerative torque thresholds corresponding to different vehicle weights (curb weight and gross vehicle weight). The determination unit dynamically selects or adjusts the appropriate threshold based on actual vehicle conditions, ensuring the stop lamp activates at the correct timing whether the vehicle is empty or fully loaded, thereby resolving the contradiction between response speed and activation accuracy.
Data Source
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AI summary
A stop lamp lighting control device for an electric vehicle having an electric regenerative braking system includes a calculation unit that converts a first deceleration threshold value for turning on a stop lamp (3) or a second deceleration threshold value for turning off the stop lamp to a first regenerative torque threshold value for turning-on the stop lamp or a second regenerative torque threshold value for turning-off the stop lamp by calculation assumed that a weight of the vehicle is a curb weight or a gross vehicle weight, and a determination unit (13) that performs a comparison between a regenerative torque value generated by the electric regenerative braking system and the first regenerative torque threshold value or the second regenerative torque threshold value and controls the stop lamp to be turned on or turned off based on the comparison result.