Collision-free path generating method in off-site robotic prefabrication and computer-implemented system for performing the same

1. A collision-free path generating method, for a robot and an end effector equipped thereon to move, comprising:

configuring a virtual working environment, containing a plurality of virtual objects at least including the robot, the end effector and a target object consisting of a plurality of basic members and mapped from a working environment in a reality, in a robot simulator;

implementing a three level of detail based three-step collision check scheme that includes three collision check steps as follows to determine boundaries for the plurality of virtual objects:

randomly sampling a combination of first robot configurations;

performing a first step based on a first level-of-detail to cover each of the plurality of virtual objects with a first collider having a pre-determined first shape and check whether a first collision is detected between a plurality of first boundaries of a plurality of the first colliders;

performing a second step based on a second level-of-detail to cover each of a plurality of components included in the each of the plurality of virtual objects with a second collider having a pre-determined second shape and check whether a second collision is detected between a plurality of second boundaries of the plurality of second colliders, if a first collision is detected during the performance of the first step;

performing a third step based on a third level-of-detail to use a plurality of mesh colliders to cover the each of the plurality of components and check whether a third collision is detected between a plurality of third boundaries of the plurality of mesh colliders, if a second collision is detected during the performance of the second step;

randomly resampling the combination of robot configurations, if a third collision is detected during the performance of the third step; and

repeatedly implementing the three level of detail based three-step collision check scheme until none of the first collision, the second collision, or the third collision is detected; and

based on the determined boundaries and the randomly resampled combination of robot configurations, performing a heuristic based pathfinding algorithm to compute a collision-free path for the robot and the end effector equipped thereon to move to the target object accordingly.

2. The collision-free path generating method as claimed in claim 1 , wherein the three level of detail based three-step collision check scheme at least includes three level-of-detail containing the first level-of-detail, the second level-of-detail, and the third level-of-detail.

3. The collision-free path generating method as claimed in claim 1 , wherein the pre-determined first shape and the pre-determined second shape is selected from a rectangular shape, a box shape, a round shape, a triangular shape, a cone shape, or a combination thereof.

4. The collision-free path generating method as claimed in claim 1 , wherein the heuristic based pathfinding algorithm is selected from one of an improved A star search algorithm, an A star search algorithm, a metaheuristic search algorithm, an inference engine algorithm, a binary search algorithm, a hill climbing algorithm, a simulated annealing algorithm, a genetic algorithm, a tabu search algorithm, a heuristic based shortest path faster algorithm, and a combination thereof.

5. The collision-free path generating method as claimed in claim 1 , wherein the virtual working environment further includes a material cutting machine, a material transportation machine, and a robot workstation.

6. The collision-free path generating method as claimed in claim 1 , wherein the plurality of basic members is the essential element used to build up a building that is constructed by implementing civil engineering based construction works and selected from one of a stud, a frame, a sheathing board, a wall panel, a floor panel, and a combination thereof.

7. The collision-free path generating method as claimed in claim 6 , wherein the building is selected from one of a house, a wooden house, a reinforced concrete building, a steel building, a steel-reinforced concrete building, a residential complex, an apartment complex, a condominium, a dwelling unit, a skyscraper, and a combination thereof.

8. A computer-implemented system, comprising:

a user equipment installed with a web browser to enable web browsing to access an internet for a user to operate; and

a cloud computing server system available on the internet providing for the user to operate via the web browser on the user equipment and configured to:

configure a virtual working environment, containing a plurality of virtual objects at least including the robot, the end effector and a target object consisting of a plurality of basic members and mapped from a working environment in a reality, in a robot simulator;

implement a three level of detail based three-step collision check scheme that includes three collision check steps as follows to determine boundaries for the plurality of virtual objects:

randomly sampling a combination of first robot configurations;

performing a first step based on a first level-of-detail to cover each of the plurality of virtual objects with a first collider having a pre-determined first shape and check whether a first collision is detected between a plurality of first boundaries of a plurality of the first colliders;

performing a second step based on a second level-of-detail to cover each of a plurality of components include in the each of the plurality of virtual objects with a second collider having a pre-determined second shape and check whether a second collision is detected between a plurality of second boundaries of the plurality of second colliders, if a first collision is detected during the performance of the first step;

performing a third step based on a third level-of-detail to use a plurality of mesh colliders to cover the each of the plurality of components and check whether a third collision is detected between a plurality of third boundaries of the plurality of mesh colliders, if a second collision is detected during the performance of the second step;

randomly resampling the combination of robot configurations, if a third collision is detected during the performance of the third step; and

repeatedly implementing the three level of detail based three-step collision check scheme until none of the first collision, the second collision, or the third collision is detected; and

based on the determined boundaries and the randomly resampled combination of robot configurations, perform a heuristic based pathfinding algorithm to compute a collision-free path for the robot and the end effector quipped thereon to move to the target object accordingly.

9. The computer-implemented system as claimed in claim 8 , further comprising one of following elements:

a computer-assisted cloud based robotic construction platform installed on the cloud computing server system and configured to provide the visualization interface for a user to operate through the web browser, wherein the computer-assisted cloud based robotic construction platform is established based on the software as a service (SAAS) technology and the platform as a service (PAAS) technology; and

the user equipment providing and running the web browser for the user to operate to access the computer-assisted cloud based robotic construction platform on the cloud computing server system remotely through the visualization interface to create an action collection.

10. The computer-implemented system as claimed in claim 8 , wherein the user equipment is selected from one of a personal computer, a notebook computer, a tablet device, a mobile device, and a smart phone.