| With the acceleration of population aging,construction sites in China are facing the problem of labor shortages.The majority of construction site workers are “post-60s” and“post-70s”.Due to the dangers in the construction industry,the roughness of operating methods and low work efficiency,young laborers cannot be attracted to enter the industry.Throughout the first industrial revolution till today,human beings have made continuous progress in various fields,such as great progress has been made in science and technology.However,the construction operation methods in the construction industry have not achieved significant progress in the past 100 years.The construction industry is still one of the least digitized and automated industries in the world,relying on the most labor.In the 21 st century,with the rapid development of robot technology,robots have been able to complete part of the work for humans.For example,industrial robots have been widely used in various fields.Facing with the increasingly prominent problems in the construction industry,robotics can bring the most innovation to the construction industry.Construction robots are an inevitable choice for the growing shortage of human resources and the only way to improve construction efficiency.Construction robots often need to move inside the building during operation,which requires planning an optimal path for the construction robots.,It is necessary to establish a constraint space to limit the behavior of the construction robot when a construction robot arrives at the construction site and starts to work.Research is carried out by analyzing the characteristics of the construction robot’s ontology and working characteristics.The main research work and innovation are as follows:(1)Aiming at the requirements that the global path planning is optimal and can avoid obstacles in real time when the construction robot enters the construction location,a new navigation map establishing method is proposed.The navigation map is established by the building information modeling(BIM)model.The geometric information and attributes of each building component are extracted for the establishment of the navigation map,which makes the process of creating the map faster.By optimizing the A * algorithm searching point to select strategy,and removing redundant turning points on the path,also the algorithm running time is shortened,and the planned global path does not close to the building wall,which reduces the collision between the robot and the wall effectively.Then,combined with BIM information to make a passability judgment for the planned path,to ensure that the construction robot will not collide with obstacles when passing through the entrances and exits in the building.Local path planning is combined with the dynamic window algorithm.The dynamic window method is used among the key points of the global path planned by the improved A * algorithm,and new braking judgment conditions are added to make the robot’s motion continuous.The experimental results show that the running time of the improved A *algorithm is reduced by more than 50% compared with the original algorithm.The length of the path is reduced by 0.4m with each redundant turning point removing,and the distance between the path and the obstacle is increased by 2 times compared with the original algorithm.After the dynamic window method is used,obstacles can be better avoided and the output control parameters are continuous.(2)According to the requirements of behavior safety of construction robots during construction,a virtual constraint space is proposed.The space information around the construction robot’s operating environment is extracted through BIM information,and the virtual robot’s dynamic constraint space is established for the construction robot’s operating space to ensure that the construction robot have No collision with some building components during construction.Through the secondary development of Unity3 D,this paper designs a constrained space simulation platform for construction robots based on Unity3 D.The virtual robot prototype can use the imported virtual 3D robot model,building virtual joints and sensors in Unity3 D,importing its 3D robot model into Unity3 D,and add joints and algorithm scripts to the model to simulate the working process of the construction robot,and get the robot’s joints and ngular information. |
