Longwall Retreat and Creep Measurement Based on UWB Radar Imaging Method

Table 9

Target positions and its errors in the radar coordinate system before and after the robot movement, and the movement displacements according to the target positions.

Targets		Real position (m)	Calculated position (m)	Error (m)
A	Before	(0.786, −2.400, 0.300)	(0.724, −2.367, 0.248)	(−0.068, −0.033, −0.052)
	After	(−0.014, −2.500, 0.300)	(−0.035, −2.541, −0.033)	(−0.021, −0.041, −0.333)
	Displacement	(0.800, 0.100, 0.000)	(0.759, 0.174, 0.281)	(−0.041, 0.074, 0.281)
B	Before	(1.386, −2.400, 0.300)	(1.366, −2.321, 0.515)	(−0.020, −0.079, 0.215)
	After	(0.586, −2.500, 0.300)	(0.624, −2.431, 0.661)	(0.038, 0.069, 0.361)
	Displacement	(0.800, 0.100, 0.000)	(0.742, 0.110, −0.146)	(−0.058, 0.010, −0.146)
C	Before	(1.986, −2.400, 0.300)	(1.921, −2.285, 0.987)	(−0.065, −0.115, 0.687)
	After	(1.186, −2.500, 0.300)	(1.191, −2.422, 0.267)	(0.005, −0.078, −0.033)
	Displacement	(0.800, 0.100, 0.000)	(0.730, 0.137, 0.720)	(−0.070, 0.037, 0.720)