Sort:
Open Access Issue
Design and experimental evaluation of an intelligent laser-engagement vehicle for competition and teaching tasks
Experimental Technology and Management 2026, 43(8): 225-234
Published: 20 August 2026
Abstract PDF (7.1 MB) Collect
Downloads:0
Objective

Conventional teaching-oriented intelligent vehicle platforms generally suffer limitations, including limited visual perception robustness, slow gimbal response, and weak coordination among the perception, control, and motion modules. In the context of integrating competition and education, these limitations prevent such platforms from meeting the demands of laboratory instruction and competition-oriented training in optoelectronic countermeasures, which require superior real-time performance, system integration, and reproducibility. These constraints make it difficult to stably reproduce the complete operation of optoelectronic countermeasures, including target search, target tracking, and laser pointing. To address these challenges, an intelligent laser engagement vehicle that integrates lightweight visual detection, gimbal servo tracking, and autonomous motion control was designed and experimentally verified. A lightweight, reliable, and highly reproducible experimental platform was established to support education and competition-oriented training in optoelectronic countermeasures.

Methods

To satisfy the functional requirements of typical optoelectronic countermeasure tasks, an integrated system architecture comprising visual recognition, control, sensing, and actuation modules was constructed. A lightweight object detection network was implemented in the perception layer to realize real-time recognition of standardized white-strip targets commonly used in laser-engagement scenarios. A dedicated dataset covering multiple scenes, viewing angles, distances, and lighting conditions was constructed, and data augmentation strategies were used to improve the generalizability of the network. The trained network was deployed on an edge inference platform to ensure low latency and real-time performance. In the control layer, the deviation of the target from the image center was used as feedback in a visual servo closed-loop control scheme. A proportional–derivative control strategy was adopted to drive the dual-axis gimbal system, thereby achieving stable and rapid adjustment in the horizontal and vertical directions. A multiprocessor embedded coordination mechanism was also designed to manage communication and task allocation among the vision module, main controller, and chassis controller, ensuring efficient data transmission and synchronous execution of perception, gimbal control, and vehicle motion. This design enabled the system to operate reliably under dynamic motion and obstacle avoidance constraints. The visual recognition performance, gimbal-tracking dynamics, and overall vehicle behavior were analyzed through standardized experiments.

Results

The constructed visual recognition module achieves a detection accuracy of more than 0.99 under strong illumination, backlighting, and complex background conditions, with an average confidence score of 0.87 and a single-frame processing delay of 17–19 ms. Gimbal-tracking experiments indicate that, with variations in the initial deviation, the target deviations in the horizontal and vertical directions converge to the preset steady-state intervals within approximately 1.2 and 1.5 s, respectively, thereby meeting the accuracy requirements for laser pointing. Vehicle-level countermeasure experiments further verify the overall performance of the system under dynamic motion and obstacle-avoidance constraints, demonstrating reliable execution of target search, continuous tracking, and laser alignment tasks with good real-time performance, stability, and repeatability. Moreover, the system executes target suppression in the dual-vehicle countermeasure scenario, with a maximum suppression distance of 181 cm, and shows potential for defense applications owing to its capabilities, such as visual camouflage, dynamic interference, and motion avoidance.

Conclusions

An intelligent laser-engagement vehicle incorporating visual recognition and gimbal tracking was developed to facilitate the integration of competition and education. By combining lightweight visual detection, visual servo closed-loop control, and efficient multimodule coordination, the system demonstrates significantly improved robustness and stability in complex environments. Experimental verification shows that the platform meets the practical requirements in terms of accuracy, responsiveness, and engineering feasibility. The system has a clear architecture, controllable cost, and high reproducibility, making it an effective experimental platform for optoelectronic countermeasure education, competition-oriented training, and related course instruction.

Issue
Measuring the appearance indicators of spherical fruits using binocular structured light 3D reconstruction
Transactions of the Chinese Society of Agricultural Engineering 2024, 40(20): 187-194
Published: 30 October 2024
Abstract PDF (1.5 MB) Collect
Downloads:18

Three typical types of spherical fruits, namely apples, oranges, and pears, have accounted for 40.86 % of the total fruit production in China in 2023. However, there is a huge trade deficit in the import and export trade of fruits in China. Furthermore, grading technology has limited the largest production and consumption of fruits. Appearance indicators, such as size, volume and deformity index, are the main external quality traits of fruits in commercial grading lines. Alternatively, computer vision has been widely used in the field of nondestructive detection of fruits and vegetables, due to the simple operation, non-contact and low cost. The surface information can be obtained to measure the external indicators using two-dimensional images. However, some limitations are still remained to capture the detailed appearance indicators, especially in the high-accuracy measurement. Compared with traditional two-dimensional images, three-dimensional (3D) imaging with the depth information can be beneficial to the appearance indicators of fruits. Among them, binocular structured light is the promising 3D reconstruction with the cost-saving, high-precision and non-contact extraction. This study focuses on spherical fruits, selecting apple, orange, and pear as representative examples, with the aim of constructing binocular structured light imaging to obtain surface contour information. The system was also validated using standard samples. Single-view point cloud reconstruction was performed as well. Three-step phase shifting was used to determine the wrapped phase. While multi-frequency heterodyne was applied to determine the absolute phase. Afterwards, stereo matching, disparity optimization, and point cloud calculation were conducted to obtain a 3D point cloud map. A rotary table was utilized to match the point cloud images from different perspectives to the same coordinate axis. Coarse point cloud registration was also achieved. A complete point cloud was obtained to conduct more precise registration using the iterative closure point (ICP) to obtain. Finally, the 3D reconstruction of spherical fruits was realized. The deformity index of the apple was extracted from the reconstruction image of single-view point cloud using normal vector angle. According to the normal vector angle, the point cloud of the fruit stem position was projected to the bottom of the fruit point cloud image. The complete fruit point cloud was improved to calculate the convex hull of the point cloud for the volume of fruit. The maximum fruit diameter was extracted through oriented bounding box (OBB) bounding box. The experimental results show that the relative error was within 3.32% in the external dimensions of standard parts using 3D reconstruction. Taking manual measurement as the references, the values of coefficient of determination (R2), root mean squared error (RMSE), and mean absolute percentage error (MAPE) were 0.97, 0.755 mm, and 7.23%, respectively, for the measured apple deformity index. In the volume of spherical fruits, R2 was 0.99, RMSE was 6.015 cm3, and MAPE was 1.946%, while those were 0.92, 1.823 mm, and 1.859%, respectively, for the maximum diameter. The 3D reconstruction with binocular structured light can be expected to significantly enhance the accuracy and efficiency in the appearance indicators of spherical fruits. The finding can also provide a valuable tool to improve fruit quality control and grading.

Open Access Issue
Geometric based apple suction strategy for robotic packaging
International Journal of Agricultural and Biological Engineering 2024, 17(3): 12-20
Published: 30 June 2024
Abstract PDF (5.5 MB) Collect
Downloads:90

Packaging is one of the least automated steps among all the fruit postharvest processes, which is time-consuming and labor-intensive. Therefore, a robust suction strategy for robotic manipulation needs to be developed. In this research, a geometric-based apple suction strategy for robotic packaging was studied, including suction cup design, optimal suction region selection algorithm, and robot system integration. In the first place, on the basis of the geometric features of the spheroid fruit, the structure of the suction cups was designed to provide reliable suction force. Then, suction force measurement experiments on both acrylic balls and apples were conducted. Based on the results, the parameters of the suction cup were finally determined. The results also indicated that the curvature radius of the suction region is supposed to larger than that of the suction cups. Furthermore, a robust suction region selection algorithm was developed, which involves four steps: RGB-D information acquisition, object detection and point cloud generation, spherical fitting, and suction region selection. Finally, the above methods were integrated into a robotic packaging system. In addition, on the basis of spatial-frequency domain imaging (SFDI) technology, early stage bruise was detected for validation. The results showed that, the proposed suction strategy and system is potential for robust robotic apple packaging.

Total 3