Simulation-driven experiments resolve throttle pedal vibration issues.

Area of Science:

• Automotive Engineering
• Vibration Analysis
• Finite Element Analysis

Background:

• Accelerator pedal vibration during horn activation is a notable NVH (Noise, Vibration, and Harshness) challenge in certain vehicle models.
• Existing research often overlooks the impact of accessory mounting points, like horns, on pedal vibration.

Purpose of the Study:

• To investigate and resolve accelerator pedal vibrations induced by horn activation in vehicles.
• To identify the root cause of vibration coupling between horn excitation and pedal bracket modal frequencies.
• To develop a cost-effective solution for reducing pedal vibration without altering production parts.

Main Methods:

• Combined finite element analysis (FEA) with real-world vibration transfer function (VTF) test data.
• Analyzed modal frequencies of the pedal bracket and resonant peaks in acceleration response.
• Conducted comparative analysis of simulated and experimental VTF curves to pinpoint structural deficiencies.
• Utilized simulation-driven optimization to identify design improvements for accessory mounting points.

Main Results:

• Identified a pedal bracket modal frequency of 355.9 Hz and a resonant peak suggesting coupling with horn excitation.
• Pinpointed structural stiffness deficiencies in the vibration transmission path from the horn to the pedal.
• Achieved an 88.4% reduction in vibration (from 544.8 mm/s² to 63.3 mm/s²).
• Demonstrated significant subjective improvement in pedal vibration perception.

Conclusions:

• The integrated simulation-testing methodology effectively resolves NVH issues related to pedal vibration.
• Optimizing accessory mounting positions is a viable strategy to mitigate vibration transmission.
• This approach offers substantial cost savings and accelerates development cycles for in-production vehicle NVH refinement.