The Navigation And Control Technology Of Teleautonomous For Small Tracked Mobile Robot

Due to the advantages of small ground pressure, strong adhesion and huge obstacle surmounting capability, tracked mobile robot has become the most preferred platform of military. Because of the light weight and portabality, the small tracked robot is extremely popular in recent years. In general, the small tracked robot works in complex combat circumstance such as city streets and inner buildings. In order to overcome the weakness of out of control after losing remote control signal, people enhance research and development efforts on independent military robots. On account of the unknown and dynamic working environment, it is much difficult to achieve autonomous navigation and control under present relative level of technology support. Thus, autonomous navigation of telecontrol still occupies an important position in future combats. With the development of sensor and computer technology, autonomous navigation technology is also becoming more and more perfect. However, owing to the small size and limited power supply capability, it is restricted in the selection of sensor and controller operation ability etc. Autonomous navigation for small mobile platform still has many problems to be solved urgently. Research of tele-autonomous navigation and control technology for small tracked mobile robot in this paper combined with the research project of “twelfth five-year” plan. This platform’s main function is coordinated with individual combat. The main research contents and contribution are described as follows.Firstly, analysis of the robot’s stress in the process of movement with established dynamic model according to the Newton Euler equation to determined the relationship between robot steering resistance and the driving force of the motor. In order to visually analyze the dynamic performance of tracked mobile robot, the virtual prototype is designed based on the dynamic analysis. The virtual prototype simulation can be predict the robot’s motion state and provide guidance for the control system’s design and hardware selection.Secondly, tele-autonomous control architecture of the small tracked mobile robot is designed to solve how to return after the robot’s telecontrol signal interrupted. The sensor and the drive device are selected reasonable and the navigation will be broken down include perceiving, localizing, planning and deciding the robot’s desired motion. The control system is divided into the upper and lower control. The study on the control system used the bottom-up method.Thirdly, tracked slip is the main reason in non-system error during the teleautonomous navigation. Therefore, slip coefficients are introduced to describe the slip effect and slip kinematic model is established. A method of slip kinematic parameter identification is presented due to the slip coefficients of variability. A series of slippage parameters of different forward speeds and steering speeds are achieved by off-line experiments. A fuzzy rule base is created based on those parameters, and the fuzzy controller is established further. This controller can be applied in robot moving control and dead reckoning. This method can be online calculated slip coefficients at the different forward speed and rotation speed, which it also corrected kinematic model real-time. By adding inertial navigation unit, the odometry and inertial guidance data fusion improved the location accuracy further. At last, a global positioning method based on landmark proposed to verify the positioning accuracy of the slip kinematic model, and the global positioning method use the scanning lidar data with the geometric relationship between road signs and robot.Fourthly, the heuristic search’s method is proposed at the path planning for the autonomous. There are two search criteria including safety performance and maximum efficiency by solved maximum and minimum value of evaluation function f to chosen the robot’s path. Vector tracking method based on screw theory is referenced and the path following control algorithm based on the behavior judgment is designed. The path planning and path following algorithm are sample and meet the real-time control for the small mobile platform. Considering the unexpected obstacle may be appear in the course of the movement, autonomous obstacle avoidance algorithm is designed by laser radar detection data. The avoidance algorithm improves the reliability of control system.In order to verify the designed scheme of tele-autonomous navigation and control system, sb RIO 9626 is used as the upper controller and Labview is wrote the program. The program including tele-autonomous pattern recognition, dead reckoning algorithm based on the slip kinematic model, path planning algorithm, the path following algorithm and the obstacle avoidance algorithm. The program testes and verified in the actual prototype. The test result shows that the control system architecture designed in this paper meet the requirement of fast response, high real-time.