Auto Hold Release Control for Smooth Brake-to-Drive Transition
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Solution Overview
Problem
The existing auto hold systems in vehicles experience unstable driving sensations due to mismatched transitions between braking force and driving power, leading to feelings of stop and connection when the accelerator pedal is pressed, which disrupt the driving experience.
Innovation Solution
An auto hold control apparatus and method that adaptively adjusts driving power parameters based on movement standard deviation of accelerations, using learning values to adjust driving power generation, inclination, and timing to synchronize braking and driving forces, minimizing discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the braking force is completely eliminated earlier than the driving power is generated, then the transition from braking to acceleration is faster, but stop feelings and connections occur causing unstable driving sensation
Solution Approach 1:
The controller generates driving power in advance before completely eliminating the braking force. By initiating the driving power generation while the braking force is still present, the system ensures that the driving power is ready and synchronized with the braking force reduction, preventing the stop feeling and connection that occur when driving power is generated too late.
Solution Approach 2:
The controller dynamically adjusts the timing and magnitude of driving power generation based on the braking force state. Instead of using a fixed timing for driving power generation, the system continuously monitors the braking force and adapts the driving power parameters to achieve smooth transition, resolving the contradiction between fast transition and stable driving sensation.
2Speed
If the driving power is increased to respond quickly to accelerator input, then the acceleration response is faster, but the mismatch with braking force reduction causes stop feelings and jittering
Solution Approach 1:
The controller continuously monitors both the braking force state and the driving power generation, and uses this feedback information to adjust the driving power parameters. By implementing closed-loop control, the system can detect when a mismatch occurs and automatically adjust the driving power to maintain smooth transition, ensuring both fast response and driving comfort.
Solution Approach 2:
The controller changes the parameters of driving power generation (such as magnitude, rate of increase, and timing) based on the braking force state. By dynamically adjusting these parameters rather than using fixed values, the system achieves both fast acceleration response and smooth transition without stop feelings or jittering.
3Stability of the object's composition
If the auto hold braking force is maintained strongly to ensure stable stop, then the stop stability is better, but the release transition becomes harsher when accelerator is pressed
Solution Approach 1:
The controller applies preliminary anti-action by generating driving power before completely eliminating the braking force. This anticipatory action counteracts the potential harshness that would result from sudden braking force elimination, ensuring a smooth transition while maintaining stop stability when needed.
Data Source
AI summary
An auto hold control apparatus obtains a driving signal for releasing an auto hold of the vehicle, through a driver, and generates driving power through the driver, based on the driving signal. The apparatus determines a movement standard deviation of an acceleration generated by the driving power from a first time point to a second time point, generate learning amount related to generated driving power, a generated driving power inclination, a driving power generation time point, or a combination thereof, based on a magnitude of the movement standard deviation, when the movement standard deviation is a threshold value or more than the threshold value. The apparatus generates a predicted learning value by adding the learning amount to a learning value which is stored in the memory in advance, and store the predicted learning value in a memory as a final learning value when the predicted learning value satisfies a predetermined condition.