Fast scanning method for container stacking profile with one laser sensor

The container stack profile scanning system is very important for yard crane automation, which is to monitor the number of containers stacked at each slot in the yard. In this paper, the novel method of scanning the container stack profile accurately and rapidly with one laser sensor is suggested. The laser sensor is mounted on the trolley, and measures the height of the container stack. The stack profile at each yard slot is monitored continuously and dynamically as the trolley and gantry move. Errors in the data of the stack height that might possibly occur due to vibration in the trolley during movement are eliminated with the use of a digital compass. The algorithm to reduce the scanning time as the crane travels on the optimum routine to minimize the movement distance is proposed. The experimental results using a simulator of yard crane are reported.