LIDAR provides data about surrounding objects within its range. In obstacle avoidance node, subscription to topic scan with message type LaserScan gives range data from 0-718 in the counterclockwise direction. LIDAR scan range is from 12 to 1000 cm is divided by 50 centimetres, that makes 20 range circles. LIDAR scan propagating on a soft target like a sofa returns 0 cm range value. It can cause an error that can cause a problem in obstacle avoidance logic, as it is interpreted as an obstacle is in the closet position. These 0's are replaced with maximum range values, that removes that constrain.
If any obstacle is found in that path, the whole arc of interest is shifted in clockwise or anticlockwise till no obstacle is detected. Left or right-side obstacle avoidance turning is decided on minimum turn angle. If no obstruction is found at L=25 cm radius circle, then the same process is applied for the next circle, till obstacle is detected.
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