| Multi-rotor UAVs have always been one of the key researches in the field of mobile robots.With the advancement of related research,the adaptability of multi-rotor UAV systems has gradually increased.However,when drones perform tasks in some relatively complex conditions,the use of only one type of drone is gradually unable to meet the needs of the work task.In this application context,the related applications of the child-mother drones have gradually attracted people’s attention.The child-mother drone is a type of child-mother robot.Its application purpose is to combine the advantages of transport robots(mother robots)in travel and data processing with the characteristics of small robots(child robots)in flexibility and speed in specific complex workspaces,which has gradually gained attention in applications such as underwater exploration and aerial surveys.In some special environments,when the traditional single flying robot is operating in the air,it is gradually unable to effectively complete the survey in the complex environment and space,and it is also lacking in attitude structure,movement mode,positioning accuracy and flight time.Therefore,the research and wide application of child-mother drones are of great significance to the application expansion of air environment monitoring,highland resource survey,land shape surveying and mapping,and large-scale agricultural operations.This article takes the sub-machine system of the child-mother drones as the research object,aiming at the trajectory planning of the sub-machine system when the child-mother drones is performing tasks in plateaus,cold regions,deep forests and other long distances and relatively complex environmental spaces.Relevant research has been carried out on related issues,the communication link test between the sub-machine and the mother machine has been completed,and based on the tracking task of the UAV,the pilot and follow-up experiment of the sub-machine has been carried out.First,by combining the dimensionality reduction ideas of the topological map method,the traditional grid map method is improved,and a grid environment modeling method that reduces the spatial dimension is proposed,which reduced the three-dimensional spatial information of the environment to the two-dimensional plane information,and reduced the complexity of the environmental model,and improved the planning and calculation efficiency of the slave system,and lay the foundation for path planning.Then,through the simulation of the A~*algorithm,the advantages of the A~*algorithm in trajectory planning are verified,and the application of the A~*algorithm in the child-mother UAV system is discussed.Combining the advantages of A~*algorithm in obtaining global path information,an improved artificial potential field(APF)method is proposed.This method first uses the A~*algorithm to generate the global path,and then optimizes the nodes of the global path,which reduces the path point information and reduces the amount of data calculation and storage.Next,the potential function in the traditional APF method is improved,and the attraction of the global path to the multi-rotor drone is introduced,so that it can guide the movement of the drone together with obstacles and target points.The simulation results show that the method can effectively correct the unreachable target and easy to fall into the local minimum problem in the traditional APF method.The traditional APF method is improved and optimized,combined with the global advantages of the A~*algorithm and real-time obstacle avoidance ability of APF method,which improved the track planning quality of the sub-machine system in static and dynamic environments.In addition,in this article,the multi-aircraft round-up mission is discussed,the UAV tracking test plan is designed,the obstacle avoidance strategy of the sub-machine system is formulated,and the sub-machine pilot and follow experiment is carried out by carrying modules such as ultrasonic sensors and visual guidance.Through experimental comparison and analysis,the transmission speed and transmission quality of the communication link data were guaranteed,and the multi-aircraft cooperative formation flight and target tracking were initially realized,which verified the validity of the test plan. |
