Path planning method and autonomous traveling robot

A path planning method, comprising:

• obtaining a target area;
• deciding a traveling path by a safety distance, wherein the traveling path is at least at the safety distance from an edge of the target area, and the step of deciding the traveling path by the safety distance comprises:
• defining a target node located on the edge of the target area,
• defining a shortest distance from the target node located on the edge of the target area to the traveling path as the safety distance;
• extending the safety distance outwardly from the target node away from the target area for an extension node being generated, wherein the extension node is located on a normal line of the edge of the target area on the target node, and the extension node is located at the shortest distance from the target node, the target area comprises a first side, and the step of extending the safety distance outwardly from the target node comprises:
• extending an extension distance from the target node along the first side for a first node being generated and defining the extension node based on the first node, wherein a projection amount of the extension distance on the normal of the first side corresponding to the safety distance is the shortest distance;
• and
• using the extension node as a path node in the traveling path;
• and
• controlling an autonomous traveling robot being moved by the traveling path, wherein the target area further comprises a second side, the target node is located at a junction of the first side and the second side, and the path planning method further comprising:
• defining a calculation included angle between the second side and a connection line of the target node and the first node;
• defining a second included angle between the first side and the second side in the target area;
• deciding whether a third included angle corresponding to the target node located at the junction of the first side and the second side outside the target area is a reentrant angle, wherein the step of deciding whether the third included angle is the reentrant angle comprises:
• deciding whether an outer product of a first vector from the target node to the first node and a second vector from the target node to the second node has a positive value;
• deciding that the third included angle is the reentrant angle in response to the outer product having the positive value;
• and
• deciding that the third included angle is not the reentrant angle in response to the outer product having a negative value, selecting, based on the determination of the outer product, a calculation mode for the extension distance associated with maintaining the safety distance from a boundary of the target area,
• in response to the third included angle being the reentrant angle, performing a reverse calculation of the extension node, wherein the reverse calculation refers to the case where the outer product has the positive value and x=−d/sin(θ), where x is the extension distance, d is the safety distance, θ is the calculation included angle, wherein the extension distance x simultaneously defines a magnitude that varies as a function of θ and a direction determined by a sign of x, wherein a negative value of the extension distance defines an inward extension direction towards an interior of the target area, and wherein the extension node is generated by the reverse calculation based on the negative value of the extension distance, and
• in response to the third included angle not being the reentrant angle, performing a forward calculation of the extension node, wherein the forward calculation refers to the case where the outer product has the negative value and x=d/sin(θ) is used to decide the extension distance, wherein a positive value of the extension distance defines an outward extension direction away from the boundary of the target area, and wherein the extension node is generated by the forward calculation based on the positive value of the extension distance.