Numerical and Experimental Analysis of Potential Causes Degrading Contact Resistances and Forces of Sensor Connectors for Vehicles

Jangmuk Lim,Tae Hee Lee,Sung Joon Park,Jae Kyun Kim,Hansu Kim,Sang Won Yoon

doi:10.1109/access.2019.2939377

Jangmuk Lim, Tae Hee Lee + Show 4 more

Open Access

https://doi.org/10.1109/access.2019.2939377

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Abstract

Faults in vehicle sensor connectors are crucial to the safety of a vehicle. Once the connector is loosened according to the reduction of its contact forces, its electrical contact resistance may be increased, causing unexpected errors in sensor systems. However, such error mechanisms have enormously diverse causes that have not yet been identified. This study proposes a process to analyze the causes influencing the connector contact force and resistance by employing a combination of numerical and experimental methods. Specifically, the causes of variation of contact force are numerically analyzed and their influence on the electrical contact resistance is experimentally studied. Precise 3D models of a commercial vehicle sensor connector are developed based on a 3D tomography, and a 3D finite element (FE) simulation is employed to estimate the connector contact force, considering plastic deformation. After classifying potential causes into three categories, two major factors are selected: manufacturing tolerance occurring during the connector manufacturing process and plastic deformation occurring during the vehicle maintenance process. The factors are observed to substantially reduce the contact force (by ~14.6 or 19%). The impact of the reduced contact force is validated in sequential experiments, and exhibits a nonlinear relationship between the contact force and corresponding contact resistance. In addition, the experiments also consider simulated manufacturing and maintenance factors, and demonstrate an increased contact resistance by the functions of the decreased contact force with minor measurement errors (< 7.5%).

Highlights

Vehicle sensors are becoming increasingly important in the performance and reliability of automobiles
This study proposes a process to identify causes affecting the contact resistance of sensor connectors used in vehicles, and focuses on the impact of reduced connector contact forces
The reduced contact-force sequentially changes the contact resistance but this mechanism is different from physical contact damages changing the resistance

Summary

INTRODUCTION

Vehicle sensors are becoming increasingly important in the performance and reliability of automobiles. The repeated disassembly-assembly processes may induce plastic deformation in the female pins and reduce the contact force. The maintenance process is reported to impose other damages on connector contacts, including fretting wear, corrosion, or peeling off of plated materials [15]–[20] As mentioned, these physical damages are not considered in this study because the sensor connectors we are analyzing are assumed to be in acceptable conditions without any damages. C. SIMULATION RESULTS AND DISCUSSION Figure 9 compares the contact force of the sensor connector derived either by the UTM test or FE simulation, after repeatedly conducting assembly and disassembly. The plastic deformation by the repeated maintenance becomes more influential in thicker male pins that more widely open the female pin To investigate the contact force-resistance relation that is not provided by the explained FE simulations, follow-up experiments are conducted

EXPERIMENT

Findings

CONCLUSION