Abstract: The coverage exploration to the environment which is detected by robots according to self-sensor in the case of global unknown environment is named for coverage path planning in the unknown environment. The algorithm can be divided into three categories; I}he first is the simple random coverage strategy, such as circuitous back and forth; The second establishes the environment contour pattern after the edgeways learning,adopts the algorithm in which the global perspective combines to the local path planning; The last is the wandering detective path planning of dori t adopt edgeways learning.

Key words: Unknown indoor environment, Edgeways learning, Coverage path planning, Exploration path planning, Rohots