In context
In early 2023, robotic painting in manufacturing was largely limited to single-color applications. Digital camouflage, essential for military equipment to evade aerial surveillance, still relied on manual masking and spraying—slow, inconsistent, and unsuitable for rapid wartime repainting. This paper tackled the core challenges of multi-color, fine-pattern robotic spraying: edge color mixing, arc transitions, and overspray.
What was reported
Researchers at Hefei University of Technology designed a rectangular spray gun with a right-angle boundary and anti-overspray features. A trapezoidal nozzle plate was attached to a conventional circular air gun, confining the conical spray into a square pattern. The paint deposition model was derived from the circular gun's parabolic model, and experiments confirmed uniform coating thickness with a virtual edge reduced from about 15 mm to 1.5 mm, effectively limiting overspray.
For path planning, the team applied Shi-Tomasi corner detection to extract digital camouflage pattern vertices and built a grid map with non-spray areas as obstacles. They improved the biologically inspired neural network (BINN) by restricting neural activity propagation to four orthogonal directions, guided by painting process rules. This reduced computational complexity and avoided diagonal path repetitions.
The 2D path was mapped onto a vehicle model surface via matrix transformation to generate a 3D spraying path. Simulations and digital camouflage spraying experiments validated the method, showing reduced computational load and successful multi-color fine spraying without overspray.
Why it mattered
This work advanced robotic painting from single-color to complex multi-color patterns, offering a path toward automated digital camouflage application. The rectangular gun design and improved BINN algorithm provide a foundation for integrating such painting tasks into intelligent production lines, potentially enabling faster, more consistent camouflage repainting in military and industrial settings.
The improved rectangular gun has a uniform coating thickness, which meets the requirements of the digital camouflage spraying process.
Source: 《机器人》期刊 (robot.sia.cn) · Published 2023-03-11 · “喷涂机器人矩形喷枪建模分析与迷彩图案全覆盖路径规划”