Warning device

A warning device comprising:

• a support stand;
• a lamp board, having at least one warning lamp, arranged on the support stand;
• an electronic component box arranged on the support stand;
• a radar module arranged in the electronic component box and configured to detect at least one target object around the radar module to generate point-cloud data, wherein a distance between the radar module and the ground is greater than a given distance;
• and
• a controller, comprising a processing module, electrically connected to the radar module and the at least one warning lamp, wherein the processing module is configured to:
• extract a frequency offset of each of data points in the point-cloud data and calculate a relative velocity and a direction of each of the data points based on a frequency relationship of Doppler effect to generate Doppler information;
• filter out the data points that fall beyond a detection range based on a distance threshold;
• filter out stationary points and dynamically moving away points of the data points and retain dynamically approaching data points based on the Doppler information;
• calculate a relative distance and a relative location of the at least one target object corresponding to the dynamically approaching points;
• and
• turn on the at least one warning lamp or increase a flashing frequency of the at least one warning lamp when the at least one target object approaches the radar module.