Vehicle type recognition method and fast vehicle checking system using the same method

A fast vehicle type recognition system, comprising:

• a radiation scanning and imaging device comprising a radiation source for generating radiations and a detection device for receiving radiations passing through a vehicle to be checked, wherein the radiation source images the vehicle to be checked by emitting radiations towards the target to be checked;
• a laser scanner for recognizing the type of the vehicle to be checked to distinguish a first portion and a second portion of the vehicle to be checked which are separated by a gap portion;
• and
• a control device for controlling the radiation source based on a signal from the laser scanner to emit radiations to irradiate the vehicle to be checked, wherein when the first portion of the vehicle to be checked enters into a radiation scanning region, the control device controls the radiation source to scan with a first dose;
• when the second portion of the vehicle to be checked enters into the radiation scanning region, the control device controls the radiation source to scan with a second dose,
• wherein the laser scanner is configured to
• detect that the vehicle to be checked has entered into a recognition area;
• move relative to the vehicle to be checked;
• scan the vehicle to be checked on a basis of columns, and storing and splice data of each column obtained by scanning to form a three-dimensional image of the vehicle to be checked, wherein a lateral width value is specified for each single column of data;
• specify a height difference threshold;
• determine a height difference between the height at the lowest position of the vehicle to be checked in data of column N and the height at the lowest position of the vehicle to be checked in data of specified numbers of columns preceding and/or succeeding to the column N,
• if
• the absolute value of the height difference is larger than the specified height difference threshold;
• the heights at the lowest position of the vehicle to be checked in data of the first N columns are all in a first predetermined range;
• a length corresponding to data of the first N columns is in a second predetermined range;
• and
• a contour spliced from the data of the first N columns complies with one of predetermined contours of head portions of vehicles,
• label a position of the vehicle to be checked corresponding to the data of the column N as a start position of a gap portion of the vehicle to be checked, the length corresponding to data of the first N columns being the length of the head portion of the vehicle to be checked in the three-dimensional image.