Abstract The pantograph–catenary system (PCS) of dual source electric trucks is an important way for the vehicle to obtain electricity from the grid. Power quality depends on the reliability of the PCS contact. It is therefore necessary to monitor the PCS by detecting the contact point (CPT) between the pantograph and the catenary. However, due to structural variations between train PCS and electric truck PCS, existing CPT detection methods designed for trains are not suitable for electric trucks. To solve this problem, this paper proposes a CPT detection method that combines semantic segmentation and linear fitting. First, a lightweight pantograph and contact line segmentation network (PCSN) is proposed to extract the pantograph and contact line regions. The PCSN comprise a lightweight encoder, Cross-Attention Fusion decoder and Hybrid Atrous Spatial Pyramid Pooling (HASPP). The lightweight encoder comprise mainly of focus and lightweight feature extraction unit. The cross-attention fusion decoder is used to fuse low-level and high-level features, and the HASPP is used to obtain multi-scale context
information. Second, we use position correction and least squares linear fitting algorithm to detect the CPT of electric trucks. Experimental results show that the proposed method's detection error is concentrated around ±5 pixels. In terms of processing speed, the proposed method can reach a high speed of 76.9 FPS (Frames Per Second) on RTX 3080 desktop computer, 47.13 FPS on CPU I9-12900, and 11.63 FPS on embedded device Jeston TX2.