Brake Lamp Control During Regenerative Braking on Sloped Roads
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Solution Overview
Problem
Existing methods for controlling brake lamps in vehicles with electric motors struggle to accurately determine deceleration on sloped roads, leading to potential lag in filter responses and inaccurate activation of brake lamps due to noise interference and varying torque outputs during regenerative braking.
Innovation Solution
A method that delays gear shifting until a gear-shifting limit is exceeded and calculates acceleration based on regenerative braking torque, correcting acceleration sensor values to ensure accurate brake lamp control, particularly on sloped roads, by using a hybrid controller that integrates regenerative-torque-based acceleration calculation and sensor correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acceleration is calculated based on regenerative braking torque during coasting, then brake lamp control accuracy is improved, but measurement precision deteriorates on sloped roads due to noise interference
Solution Approach 1:
The patent introduces an intermediary filtering mechanism that processes the raw acceleration signal from regenerative braking torque calculation. The filter acts as a mediator between the noisy torque-based acceleration signal and the brake lamp control system, removing high-frequency noise while preserving the underlying deceleration trend, thus resolving the contradiction between measurement precision and reliability
Solution Approach 2:
The system implements feedback by continuously monitoring the calculated acceleration from regenerative braking torque and using this information to adjust brake lamp control decisions. The feedback loop allows the system to adapt to varying road conditions and maintain reliable brake lamp operation despite noise interference in the acceleration measurement
2Productivity
If gear shifting is performed during regenerative braking, then vehicle efficiency is improved, but acceleration calculation accuracy deteriorates due to torque variations
Solution Approach 1:
The patent applies preliminary action by detecting gear shifting events in advance and proactively adjusting or pausing the acceleration calculation process before torque variations occur. This prevents the torque fluctuations during gear shifting from corrupting the acceleration measurement, while still allowing gear shifting to proceed for vehicle efficiency
Solution Approach 2:
The system dynamically adjusts the acceleration calculation methodology based on gear shifting status. When gear shifting is detected, the system switches to an alternative calculation mode or temporarily suspends torque-based acceleration calculation, thereby maintaining measurement precision while allowing gear shifting operations to improve vehicle efficiency
3Speed
If filter response time is reduced to improve responsiveness, then brake lamp activation speed is improved, but noise interference increases leading to inaccurate activation
Solution Approach 1:
The patent changes the parameters of the filtering process by optimizing the filter cutoff frequency and response time constants. By carefully selecting these parameters, the system achieves a balance where the filter responds quickly enough for timely brake lamp activation while still effectively rejecting noise, thus resolving the contradiction between speed and measurement precision
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the reliability of acceleration determination during regenerative braking, ensuring proper brake lamp operation and compliance with regulations, thereby improving safety and marketability by reducing lag and noise-related errors.
Implementation Method 1
a motor in addition to a conventional hydraulic friction brake is operated by a generator during braking, and thus, the kinetic energy of a vehicle is converted into electrical energy to thereby enable the vehicle to brake
Data Source
AI summary
A method of controlling a brake lamp of a vehicle including an electric motor as a power source includes determining whether gear shifting is required and whether there is a forward section with a suddenly changing slope when regenerative braking is performed through the electric motor without manipulation of an accelerator pedal or a brake pedal, delaying the gear shifting until the gear shifting exceeds a gear-shifting limit when the gear shifting is required and when there is the forward section with the suddenly changing slope, calculating acceleration based on regenerative braking torque while the gear shifting is delayed, and controlling the brake lamp based on the calculated acceleration.