Design And Implementation Of Mobile Robot Membrane Controller For Obstacle Avoidance Behavior

Membrane computing is a new branch of natural computing.It is a kind of computing model abstracted from cell structure.It has the same computing power as Turing machine.Membrane computing is introduced into the field of mobile robot control due to its advantages of parallelism,modularization,distributed and scalability.Using membrane computing(membrane systems)to design robot controller has become a new way of designing controller.Obstacle avoidance is the basic behavior of mobile robots,and it is very important for robots to complete tasks safely.The parameters of the existing membrane controller for obstacle avoidance are fixed,which can not balance robot speed and performance of obstacle avoidance.In order to solve this problem,the paper studies the mobile robots membrane controller for obstacle avoidance.The main work is as follows:1.The paper analyses enzymatic numerical membrane controller(ENMC)based on the existing control law of obstacle avoidance.The paper summarizes the law of parameter selection of ENMC and experimentally analyzes factors affecting control effect of ENMC for obstacle avoidance.The paper analyzes the relationship between sensor values and obstacles and analyzes the change of robot rotation angular velocity during obstacle avoidance.From the perspectives of Kinematics,The paper analyzes the obstacle avoidance behavior of the robot controlled by ENMC.2.Two kinds of mobile robots ENMCs for obstacle avoidance are designed.In order to facilitate the design of ENMC,a sequential execution design method of ENMC is presented.the enzymatic variables are used to select the execution rules and the enzymatic variables are placed in production function so that they are cleared after the execution of the rules.These ensure the rules are executed only once in the whole cycles.Then a rule executed only once is designed to activate the next cycle of enzymatic variables.So the sequential execution of the ENMC is realized.Then,according to the sequential execution method,a distance-adaptive cruise speed ENMC is designed.The ENMC fuses sensors' information to obtain the total distance measurement value between robot and obstacle.The cruise speed is adjusted by the value,so that the cruise speed changes adaptively with the distance between robot and obstacle.In order to reduce the experiential parameters and consider the influence of robot itself on obstacle avoidance,a distance and angular velocity-adaptive cruise speed ENMC is designed according to the sequential execution method of ENMC.According to the robot kinematics analysis,the ENMC adjusts the cruise speed by the robot angular velocity and the distance from obstacle to the center of robot,balancing robot speed and performance of obstacle avoidance.3.Design simulation and physical experiments to verify the validity of ENMCs.Build the experimental platform and simulation,physical experimental sites.Make obstacle avoidance experiments on Pioneer 3-DX simulation and physical robot.The experimental results show that the distance-adaptive cruise speed ENMC and the distance and angular speed-adaptive cruise speed ENMC can balance robot speed and performance of obstacle avoidance,and have a better control performance for robots' obstacle avoidance.