About sweeping robot

With A 1. Development of, Regardless of the unit or the family, "intelligence" is increasingly occupying people's lives. The word "robot" has been familiar to thousands of families. When it comes to "robots", most people think of humanoid walking robots. However, in recent years, there has been an upsurge of home intelligent robots, such as Rokid robot, pudding robot, Xiaobai, Xiaoyi, etc These home intelligent robots are interactive robots That is to say, they communicate with human beings through language. They have one thing in common - they have no wheels and can only be placed on the table. This is precisely their weakness and scope limitation. Therefore, another robot system - wheeled mobile robot was born.

As a typical representative of mobile robots, wheeled mobile robots are widely used in military, transportation, industry and And other fields play an important role. For example, China has used wheeled mobile robots to explore the moon and developed the Yutu wheeled mobile robot. According to the shape and function of mobile robots, many wheeled mobile robots with different structures have been developed in all walks of life in China. Nowadays, wheeled mobile robots have entered the family, which is the family wheeled mobile robot - sweeping robot. Today, I'm going to talk about this sweeping machine and the inxni sweeping robot produced by Shenzhen Silla Company.

About the Optimal Path

The floor sweeping robot in Inxni is equipped with two wheels and established by laser scanning Map, complete the bow shaped cleaning path. However, no matter the furniture or obstacles in the house, they will disrupt the walking path of the sweeping robot. If you want to successfully complete the cleaning task of the whole room, the sweeping robot must repeat a certain route.

As early as 1960, Professor Guan Meigu first raised the issue of postman in the world, and now it is named "China's Postal Route Problem" by the international graph theorists. The problem of China's postal route, in short, is how the postman delivers the letter, and how to walk the shortest path to send the letter to the designated user. The problem of the optimal cleaning route of the sweeping robot is the same as the problem of China's postal route, that is, the shortest path to clean the house.

On the Optimal Path Scheme

We can study the optimal route of robot cleaning through examples. Assume that the following figure is a two-dimensional map of a room, where there are stools and sofas And other furniture. The circle in the figure represents the sweeping robot, and the number in the circle represents the walking route of the sweeping robot. According to the research idea, the sweeping robot needs to walk through more than ten positions in the map and ensure that the walking route is the shortest path to achieve the optimal and energy-saving goal we expected.

We ordered the sweeping robot to start from the lower left southwest corner of the room and sweep along a straight line to the northwest corner of position 2. Then walk past position 3 to position 4 and 5. The sweeping robot walked south all the way to the position 6 in the southeast corner. Similarly, the sweeping robot moves to position 11 in the center. From position 11, the sweeping robot must return to the original position 8, that is, position 8 is the same as position 12. The sweeping robot passes from position 12 to position 13 to position 14, where the path from position 12 to position 13 is to repeat the previous positions from 8 to 9. The sweeping robot walked to position 18 according to the number marked in the figure, and finally returned to position 1 of the initial point to complete the cleaning of the whole house. Among them, the three sections of Route 3-4 (14-15), 8-9 (12-13) and 17-18 (16-17) in bold in the figure are the routes that have been taken twice. However, this is a sub optimal route with relatively few repeated routes. The so-called sub optimal route is second only to the optimal route. However, this sub optimal route has made good use of existing resources, and resources are relatively optimized.

Next, I would like to introduce you to an optimal route. The same is the example above. In a room, there are two obstacles, a stool and a sofa. We need to complete the cleaning plan of the optimal route design. As you can see, position 1 in the figure below is the starting point of the sweeping robot. After walking through the room according to the figure in the figure, the sweeping robot still repeated two routes 15-16 (16-17) and 6-7 (11-12). However, in this example, we can see that the route of Scheme 2 is shorter than that of Scheme 1, that is, Scheme 2 is the optimal route. However, Scheme 2 also brings a problem: the starting position of the sweeping robot is not in the corner, and it will not return to the starting point eventually.

When we study the optimal route problem, we should mark the length of the actual distance in the path. In the above example, we can see that Scheme II is the optimal scheme. However, in most cases, we need to calculate the actual distance of the path to determine the optimal scheme.

　　 About questions

　　 Question 1:

The above two schemes specify the furniture in the room and the specific location of the furniture, which belongs to a specific situation. How can this method be extended to all house types?

answer:

This optimal path cleaning scheme is a special innovation of sweeping robots within bits. Because the internal sweeping robot has its own app, and can create a two-dimensional home map by laser scanning before sweeping. Therefore, the app can mark the location of furniture on the map and add it to the two-dimensional map, calculate the shortest path through the method I introduced above, and mark the initial position of the sweeping robot for users to easily use the robot.

　　 Question 2:

Since it is the optimal path, why not design a scheme to make the path of the sweeping robot not repeat and complete the cleaning task of the house at one time?

answer:

According to the thought of China's postal route problem, if there are only two branches at any point where the postman or the sweeping robot walks, the cleaning task can be completed at one time, without having to repeat it. However, if there are three or more branches at a certain point, the sweeping robot will surely walk out of the second branch and walk back to the point from the third branch. As shown in Scheme 2 above, position 4 has only two branches: north and east, so the sweeping robot must enter from one branch of position 4 and exit from the other. However, if there are three branches at position 6 in Scheme II, the sweeping robot will surely enter from one branch, exit from the second branch, enter again from the third branch, and repeat the adjacent route to exit.

Therefore, the optimal path design scheme is not perfect. The optimal path scheme is only the shortest path for the sweeping robot to walk, and cannot make the sweeping robot complete the sweeping task at one time.