• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2026, Vol. 62 ›› Issue (15): 324-333.doi: 10.3901/JME.260324

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Tire Pose Estimation and Robotic Depalletizing Method Integrating Covariance Analysis and Random Sample Consensus

WANG Huiqiang1, LI Xiangfei1, ZHAO Huan1, LI Nan2, YUAN Guanzhe1, DING Han1   

  1. 1. State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074;
    2. Zhiyan Automatic Equipment Hubei Co., Ltd, Xianning 437000
  • Received:2025-08-17 Revised:2025-11-25 Published:2026-10-13

Abstract: In the automotive industry, the depalletizing process for tire assemblies presents several challenges. The workpieces are heavy, and the process demands strict timing and stability requirements. Additionally, the floating positioning of the workpieces makes it difficult to achieve efficient automation through traditional robot teaching methods. Current mainstream approaches, such as manual depalletizing and overhead crane-assisted handling, suffer from low automation levels. Manual depalletizing, while meeting timing requirements, involves high labor intensity and costs, along with short-term risks of falling materials and long-term occupational hazards. To address these issues, an automated depalletizing method is proposed for tire assemblies using industrial robots and a structured light 3D camera for spatial pose recognition. The method considers the spatial stacking of tire assemblies and their pallets, as well as the specific requirements of the depalletizing process. It includes a point cloud measurement and data preprocessing procedure to ensure data integrity and computational accuracy. Since tire surfaces are not simple parametric models, the method refines point cloud boundaries by analyzing their geometric features, calculating covariance matrices, and applying normal vector filtering. A spatial pose calculation process is also designed to meet the automation needs of the depalletizing operation. We built an experimental platform using industrial robots and area-structured light 3D camera to implement the proposed measurement, calculation and depalletizing methods. Repeated tests confirmed the effectiveness of the spatial pose recognition approach in automating the tire assembly depalletizing process. The results demonstrate a 100% recognition accuracy, a repeatability precision of less than ±5 mm, an average algorithm processing time under 1.2 s for multiple tires in single layer, and a total cycle time (including measurement, computation, and robot depalletizing) of less than 13 s per workpiece. The experimental results indicate that the proposed method achieves significant improvements in efficiency, labor cost reduction, and safety risk mitigation compared to traditional approaches.

Key words: industrial robots, area-structured light, automated depalletizing

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