Field and Laboratory Evaluation of Reliability in a Novel Cone Deployment System for Safer Highway Operations

Abstract

This study evaluates the reliability and maintainability of the Cone Collecting and Laying (C2L) machine, developed to enhance safety and efficiency in highway maintenance operations by automating the deployment of traffic cones. The objective is to investigate the use of reliability metrics, which are Mean Time to Failure (MTTF), Mean Time to Repair (MTTR), and Mean Time Between Failures (MTBF), as a systematic approach to assess the operational efficiency and failure behavior of the C2L machine in real highway maintenance scenarios. The methodology encompasses controlled laboratory and field testing conducted over 68 hours in Test Motion A and 3,192 hours in Test Motion B. During these tests, real-time failure data were recorded for six critical components of the C2L machine, namely the bearing, cone lifter, chain, sensor, PLC, and hook spring. Findings from Test Motion A revealed component vulnerabilities, including a low MTTF in bearings and a high MTTR in welded joints. In contrast, Test Motion B identified frequent failures in the PLC system, attributed to vibration stress, as well as a rare but critical hook spring failure caused by material fatigue. All reliability metrics were calculated from empirical failure and repair times, enabling accurate quantification of component durability and overall system availability. Failure data were further categorized into repairable and non-repairable types to inform targeted design improvements. In conclusion, integrating MTTF, MTTR, and MTBF into the evaluation of the C2L machine proved essential for identifying weaknesses and enhancing operational performance. The study recommends proactive maintenance scheduling, structural reinforcement, and redesign of vulnerable components to ensure system resilience. These findings contribute to improved worker safety, reduced operational downtime, and the enhanced long-term deployment potential of the C2L machine in highway maintenance applications.

ABSTRAK: Kajian ini menilai kebolehpercayaan dan kebolehselenggaraan mesin Pemungut dan Meletak Kon (C2L) bagi meningkatkan keselamatan dan kecekapan operasi penyelenggaraan lebuh raya melalui automasi proses meletak dan mengutip kon trafik. Objektif kajian ini adalah meneliti penggunaan metrik kebolehpercayaan seperti Masa Purata Sebelum Kegagalan (MTTF), Masa Purata Membaiki (MTTR) dan Masa Purata Antara Kegagalan (MTBF) sebagai satu pendekatan sistematik bagi menilai kecekapan operasi serta tingkah laku kegagalan mesin C2L dalam situasi penyelenggaraan lebuh raya sebenar. Kaedah ini merangkumi ujian makmal dan ujian lapangan terkawal yang dijalankan selama 68 jam bagi Ujian Gerakan A dan 3,192 jam bagi Ujian Gerakan B. Sepanjang ujian tersebut, data kegagalan masa nyata direkodkan pada enam komponen kritikal mesin C2L, iaitu pengalas, pengangkat kon, rantai, pengesan, PLC dan spring cangkuk. Penemuan daripada Ujian Gerakan A menunjukkan kelemahan komponen termasuk MTTF yang rendah pada galas serta MTTR yang tinggi pada sambungan kimpalan. Sebaliknya, Ujian Gerakan B mengenal pasti kegagalan kerap pada sistem PLC akibat tekanan getaran, serta kegagalan kurang tetapi kritikal pada spring cangkuk disebabkan oleh kelemahan bahan. Semua metrik kebolehpercayaan dikira daripada data empirikal masa kegagalan dan masa pembaikan, sekaligus membolehkan pengukuran ketahanan komponen serta ketersediaan keseluruhan sistem. Data kegagalan turut dikategori pada jenis boleh dibaiki dan tidak boleh dibaiki bagi menyokong penambahbaikan reka bentuk terfokus. Kesimpulan, integrasi MTTF, MTTR dan MTBF dalam penilaian mesin C2L terbukti penting bagi mengenal pasti kelemahan serta meningkatkan prestasi operasi. Kajian ini mengesyorkan jadual penyelenggaraan proaktif, pengukuhan struktur, dan reka bentuk semula komponen yang lemah bagi memastikan daya tahan sistem. Dapatan ini menyumbang kepada peningkatan keselamatan pekerja, pengurangan masa henti operasi, serta potensi penggunaan jangka panjang mesin C2L dalam aplikasi penyelenggaraan lebuh raya.