fixed sonar step backward
fixed sonar step backward

SyllogismRXS/opencv-workbench,SyllogismRXS/opencv-workbench,SyllogismRXS/opencv-workbench,SyllogismRXS/opencv-workbench,SyllogismRXS/opencv-workbench,SyllogismRXS/opencv-workbench,SyllogismRXS/opencv-workbench