Research On Multi-robot Path Planning Control Algorithm Based On Hexagonal Grid Ma

Nowadays,robots are widely used in various fields.Path planning algorithm and multi-robot cooperative formation strategy are important research contents in robotics.This paper mainly studies the path planning of multiple robots and formation control,and the problem is transformed into the path planning problem of multi-robots entirety and the cooperative formation problem of multi-robots.In this paper,the improved JPS+ algorithm and the improved D~* algorithm under hexagon map are combined to solve the problem of path planning,and a cooperative control strategy combining leading-following and virtual structure is proposed to solve the problem of multi-robot cooperative formation.Finally,the simulation verification of two-wheeled differential robots is carried out in ROS environment.The main research contents of this paper are as follows:Firstly,the JPS+ static path planning algorithm based on square map is studied,and an improved JPS+ algorithm based on hexagon map is proposed.The hexagon map is used to replace the square map for path planning,and the coordinate representation and distance solution method of hexagon map are analyzed.On the basis of traditional JPS+ algorithm,map expansion operation is added to ensure that the planned trajectory and obstacles keep a certain safe distance.The evaluation function is improved as time cost,and the turning time is considered,so that the planned trajectory has less total travel time.Add path smoothing operation,so that the planned trajectory is not limited by the fixed turning Angle of grid map.Secondly,the D~* dynamic path planning algorithm based on square map is studied,and an improved D~* algorithm based on hexagon map is proposed.For the problem that the trajectories planned by D~* algorithm follow dynamic obstacles,a kind of weighted incremental method is proposed to forecast track dynamic obstacles.The improved D~* algorithm improves the cost estimation function from the current point to the end point according to the predicted trajectory and the current planned trajectory,so that the planned trajectory can avoid obstacles in advance.Then,aiming at the problem of multi-robot cooperative formation,a control strategy combining pilot-following method and virtual structure method is proposed.The multi-robot entirety is regarded as a virtual circle,and the relative position of each robot in the entirety is fixed.For the following robot,the control strategy combining velocity feedforward and position feedback is adopted to control the following robot to follow its local target point well.In the process of moving,follow the strategy of avoiding obstacles without changing formation as much as possible.When the terrain cannot be passed without changing formation,the compression ratio is determined according to the width of terrain and the entirety current position to compress formation.Finally,the algorithms proposed in this paper are verified successively in ROS environment.The simulation environment was built in Gazebo simulation software and gmapping was used to build the map.On the constructed map,the improved JPS+algorithm is used for static path planning,and the improved D~* algorithm is used for dynamic path planning.Combined with multi-robot formation strategy,static path planning algorithm and dynamic path planning algorithm,the entirety simulation experiment is carried out,and the effectiveness of the algorithm is verified.