Accelerator Pedal Effort Control Device Hunting Phenomenon
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing accelerator pedal effort control devices cause undesired vehicle behavior and uncomfortable driving experiences due to rapid changes in pedal effort, leading to a 'hunting phenomenon' when transitioning between different engine operating ranges, which affects fuel efficiency and drivability.
Innovation Solution
An accelerator pedal effort control device that includes an accelerator opening angle sensing mechanism, a pedal effort varying mechanism, and a threshold value setting system, where a predetermined increment is added to the pedal effort when the opening angle exceeds a threshold value, and this increment is only cancelled after a predetermined period has elapsed, preventing sudden reductions in pedal effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the pedal effort is rapidly increased when transitioning from the second operating range to the boundary operating range to reduce fuel consumption, then fuel efficiency is improved, but the accelerator pedal is pushed back contrary to the driver's intention, causing hunting phenomenon and deteriorating drivability
Solution Approach 1:
The patent applies dynamics by making the pedal effort characteristic changeable based on operating conditions. The ECU dynamically adjusts the pedal effort increment cancellation timing based on detected operating parameters (engine speed, accelerator opening angle, vehicle speed), transforming the static pedal effort system into a dynamic one that adapts to real-time conditions to prevent hunting phenomenon while maintaining fuel efficiency.
Solution Approach 2:
The patent changes the parameter of pedal effort increment cancellation timing based on operating conditions. Instead of using a fixed threshold, the system varies the cancellation timing parameter according to engine speed, accelerator opening angle, and vehicle speed, allowing optimal balance between fuel consumption reduction and maintaining natural accelerator pedal operating feeling under different driving conditions.
2Speed
If the increment of pedal effort is immediately cancelled when returning from the boundary operating range to the second operating range, then the pedal effort control responsiveness is improved, but the accelerator pedal rattling occurs contrary to the driver's intention, causing uncomfortable feeling and deteriorating vehicle drivability
Solution Approach 1:
The patent applies preliminary action by predicting potential hunting phenomenon based on current operating conditions before it fully manifests. The ECU proactively delays the cancellation of pedal effort increment when conditions suggest the accelerator opening angle is approaching the boundary range, preventing the oscillation before it occurs and maintaining accelerator pedal stability while preserving control responsiveness.
3Loss of energy
If the pedal effort increment is used to reduce specific fuel consumption, then fuel efficiency is improved, but the hunting phenomenon occurs at the boundary operating range, affecting the quality of the whole vehicle
Solution Approach 1:
The patent applies feedback by continuously monitoring operating conditions (engine speed, accelerator opening angle, vehicle speed) and using this information to adjust the pedal effort increment cancellation timing. The ECU creates a closed-loop control system where the output (pedal effort) is continuously adjusted based on feedback from the system state, ensuring fuel efficiency improvement while maintaining reliable vehicle drivability quality by preventing hunting phenomenon.
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
[Object] To suppress rattling of an accelerator pedal which is caused in the vicinity of an accelerator opening angle threshold value at which pedal effort is increased, contrary to the driver's intention. [Construction] When an accelerator opening angle has reached an accelerator opening angle threshold value APS1 corresponding to a boundary of a range in which a fuel consumption is relatively deteriorated, a pedal effort of accelerator pedal 2 is increased by a pedal effort increment with respect to a base pedal effort. Even in a case where a the accelerator pedal is pushed back to reduce the accelerator opening angle due to an increase in pedal effort when the accelerator opening angle exceeds the accelerator opening angle threshold value APS1, cancellation of pedal effort increment is inhibited to thereby ensure suppression of rattling of accelerator pedal 2 contrary to the driver's intention.