Research On Automatic Driving Control System Of Truck AGV

With the advancement of the modernization process,the current smart factory has a great demand for the automation of material handling,and the research on the AGV control system with good performance has important economic and social value.Relying on the school-enterprise cooperation project,this subject has carried out research on the motion control problem of heavy-duty truck AGV working in an outdoor complex factory environment,with the aim of designing a stable and reliable automatic driving control system.Firstly,the differential GNSS is used as the navigation mode of truck AGV,and the touch configuration screen is used as the human-machine interface to collect and input the path station.Then,based on the analysis of the advantages and disadvantages of different AGV layout modes,the kinematic model and simplified model of truck AGV are established by using the rear wheel drive AGV with front wheel steering as the experimental research platform The communication requirements between the control system and external modules are analyzed,and the vehicle communication system is designed.Secondly,the control system was designed from two aspects: the hardware design and the software algorithm design of the truck AGV control system.Starting from the functional requirements,the control system must complete information interaction with external modules to obtain the current pose information,expected path and speed,and surrounding obstacle information of the truck AGV.After processing by the control system,the steering,speed and braking commands are sent to the bottom layer.Execution system.Considering the calculation speed,application scenarios,development experience and other factors,the STM32F407VET6 single-chip microcomputer is selected as the main controller of the control system,and combine the communication requirements to design the peripheral circuit of the controller and PCB circuit board.Then,according to the path planning based on Bessel curve idea,the path planning of straight line and turning section is carried out for the route station.Through literature review,the advantages and disadvantages of existing common control methods are analyzed.Combined with the complexity of AGV operation environment route and low-speed operation characteristics,the pure tracking algorithm is selected as the horizontal tracking algorithm,and the straight line section is passed on Spyder software The feasibility of this control method is proved by the simulation experiment.In the simulation experiment,it is found that the value of preview distance is an important parameter that affects the control effect of tracking curve.It is bound with the vehicle speed to find the mathematical relationship between them,and the dynamic preview distance is used to optimize the control effect.In order to reduce the static deviation between the tracking curve and the target curve,the forward and reverse steering compensation angle is introduced and a compensation value is added to the expected wheel angle obtained by the pure pursuit algorithm.Through the simulation experiment in the turning section,it is verified that compared with the right angle turning and the manual trial and error method,it can improve the vehicle attitude smoothness and work efficiency in the process of running.Finally,the accuracy,stability and rapidity of the control system are verified by real vehicle experiments.The influence of the forward and reverse compensation angle on the tracking control effect is verified by experiments.It is verified that the static deviation of AGV path tracking can be reduced by the steering compensation angle proposed in the previous paper.Through the re positioning accuracy experiment,it is verified that the re positioning accuracy after parking does not exceed ± 20 mm,which can meet the requirements of engineering The results show that the AGV control system designed in this paper can meet the requirements of the factory for the operation accuracy and stability of the truck AGV;through the disturbance experiment with large deviation in the departure position,the good fast response of the control system is verified;through the path tracking experiment under the complex "U" curve,the adaptability of the control system to the complex path is verified;the experimental results show that the AGV control system designed in this paper can meet the requirements of the engineering The actual operation demand of AGV truck in the factory.