{
  "abstract": "Kinematic redundancy and fractional-order sliding-mode control (FOSMC) are seldom combined in fault-tolerant manipulation. Here, they are combined on a rail-mounted SCARA arm subject to actuator loss of effectiveness (LOE) and elbow locking. The sliding surface contains a Riemann–Liouville integral of order λ∈(0,1], with λ=1 giving the integral sliding mode (ISMC). Ultimate boundedness is proved under LOE, a post-lock feasibility condition yields a fault-aware redundancy resolution rule, and the short-memory Grünwald–Letnikov implementation is shown to be an exact convolution with a truncated kernel for which the sliding dynamics are stable for any memory length. With jointly tuned gains, a common activity budget, and no added lag or delay, the accuracy-tuned FOSMC-J lowers the tracking error by 49% without faults and by 67% under LOE relative to the best ISMC (20 runs per case; 1.5–2.5 Hz disturbance). However, with an actuator lag of 2 ms, FOSMC-J failed in 9 of 10 lock runs. The moderate-gain FOSMC never failed with 2–4-ms lag, but tolerated less delay than the equal-gain ISMC. Under the lock condition, moderate-gain controllers of both orders always recovered, while high-gain controllers failed in about a third of 100 runs, with a violated margin (integer) or deep saturation (fractional). Moderate gains at reconfiguration removed almost all of the failures.",
  "abstract_shown": true,
  "affiliations": [
    "Electrical Engineering Department, Faculty of Engineering, Universidad de Santiago de Chile, Las Sophoras 165, Estación Central, Santiago 9170124, Chile"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Claudio Urrea",
      "orcid": "0000-0001-7197-8928"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/70fp4vx9myzys.bib",
  "cited_by": 0,
  "doi": "10.3390/fractalfract10110748",
  "fulltext_url": null,
  "id": "70fp4vx9myzys",
  "issns": [
    "2504-3110"
  ],
  "landing_url": "https://www.mdpi.com/2504-3110/10/11/748",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2207|Adaptive Control of Nonlinear Systems"
    ]
  ],
  "openalex": "W7223884000",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/70fp4vx9myzys.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:32Z",
      "native_id": "10.3390/fractalfract10110748",
      "source": "crossref",
      "url": "https://www.mdpi.com/2504-3110/10/11/748"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "issn:2504-3110",
      "subfield": "analysis-pdes"
    }
  ],
  "title": "Fractional-Order Sliding-Mode Control of a Rail-Mounted Redundant SCARA Under Actuator Degradation and Elbow Locking: Truncated-Memory Analysis and a Reproducible Simulation Benchmark",
  "title_text": "Fractional-Order Sliding-Mode Control of a Rail-Mounted Redundant SCARA Under Actuator Degradation and Elbow Locking: Truncated-Memory Analysis and a Reproducible Simulation Benchmark",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:32Z",
  "url": "https://research.draconitic.com/paper/70fp4vx9myzys",
  "venue": "Fractal and Fractional",
  "versions": []
}