Design And Application Of Low Speed Unmanned Driving Controller

With the development of manufacturing industry,low-speed unmanned vehicles are widely used in modern industrial fields.In view of the complexity of the operating environment,customers have put forward higher requirements on the stability and flexibility of the hardware system and the real-time and modularity of the software system of the vehicle controller.In this context,this paper is focused on the modularization of controller hardware and software functions,aiming to design a low cost,stable and reliable hardware performance,real-time software system and modularity of the low-speed unmanned controller to meet customer needs and enhance the competitiveness of the enterprise market.By reviewing relevant literature,this paper firstly studied and analyzed the current situation of domestic and foreign research on low-speed unmanned controller;secondly,the technical research was carried out in three aspects: overall system design,controller hardware circuit design and controller software design,with the construction of low-speed unmanned controller as the core;finally,based on the above research,the real-world experiment of low-speed unmanned controller was conducted to verify the accuracy and effectiveness of the proposed method.The main research of this paper is as follows:The hardware of the low-speed unmanned controller is designed.The hardware system mainly includes schematic design and PCB design;for schematic design,the schematic diagrams of the controller power management module,serial communication module,digital and analog signal acquisition module,high-power driver module,and Flash module are designed;for PCB design,the PCB is designed from layout and The PCB design is designed from the layout and wiring aspects by analyzing the effects of PCB electromagnetic interference,serial interference and analog-to-digital signal interference.The software of the low-speed unmanned controller was developed.Firstly,for the system software,through the analysis of domestic and foreign operating systems,combined with the microcontroller used in this paper,RT＿Thread real-time operating system is adopted as the programming framework;secondly,for the application software,the functional modular design of modules such as positioning and navigation module,path planning module,path tracking module and motion control module is carried out based on the thread approach;for the path tracking module,the A path planning and tracking control method based on Bessel curve is proposed,which solves the problem that the vehicle will not have a smooth tracking path in the turning section after the smooth path is transformed into a zigzag path because the controller reduces the number of global path points to save Flash memory;in addition,a path tracking method based on fuzzy control is proposed,in which the lateral deviation and speed change are used to develop corresponding fuzzy rules,so that the vehicle can realize the function of dynamic pre-sighting distance and improve the self-adaptive ability of the vehicle.Finally,the rapidity,accuracy and stability of the control system in this paper are verified by real vehicle experiments.Firstly,the experiments of path planning and tracking control method based on Bessel curve have achieved a good tracking control effect while achieving smooth turning of the vehicle;secondly,the experiments of dynamic pre-targeting distance method based on fuzzy control have verified the function of dynamically adjusting pre-targeting distance based on the change of vehicle speed and lateral error;again,three experiments have been conducted based on the influence of initial lateral error on tracking control effect,the influence of speed on tracking control effect,and the influence of heading angle deviation on tracking control effect.The controller has the characteristics of "fast,stable,and accurate" through three experiments based on the influence of initial lateral error on tracking control effect,the influence of speed on tracking control effect,and the influence of heading angle deviation on tracking control effect.