Development Of Intelligent Driving System For In-place Material Recycle Heating Machine

Hot In-place Recycling technology is a preventive asphalt pavement maintenance technology,Its advantages of economic and environmental protection,fast construction speed,low traffic impact and so on,so that is widely used in the world in recent years.However,its harsh construction environment,such as high temperature and noise,endangered the health of construction workers on site,resulting in higher and higher labor costs,so it is necessary to realize the intelligent driving of vehicles.In this paper,we analyzed the demand for intelligent driving system based on the construction environment and construction technology of the In-place Material Recycle Heating Machine.And according to the high temperature environment on site,we propose one Intelligent driving system which based on the Differential GPS positioning sensor.Our proposed system tested in the In-place Material Recycle Heating Machine which was produced by Shandong Road and Bridge Group Co.,Ltd.Test results show that the system meets the initial design requirements.Firstly,the differential GPS positioning technology is introduced in detail.Based on the positioning technology,a path planning system is designed to extract the information of road registration points.The registration point information is based on the WGS84 geodetic coordinate system,and the system needs to use gauss plane rectangular coordinates,so it needs to be converted into coordinates in the Beijing 54 plane coordinate system through certain coordinate conversion.In the Beijing 54 plane coordinate system,the path information sampling point data is fitted by the least square method to generate the path information,and the path fitting effect is verified by MATLAB platform simulation.Secondly,the overall scheme of intelligent driving vehicle control system is designed,also complete the hardware design and assembly work of the vehicle master controller.A steering device for heating machine based on servo motor is designed to realize automatic control of vehicle steering.The angular transducer and its attached circuit are used to collect the steering status information of the wheel and transmit it to the vehicle master controller through CAN bus.The vehicle controller calculates the difference between the given steering Angle of the wheel and the actual Angle.The vehicle position coordinates are received by the GPS receiver,and the shortest distance between the vehicle position and the path information is calculated in the Beijing 54 plane coordinate system.The distance is used as the deviation signal to adjust the PID of the vehicle trajectory,to realize the closed-loop control of the vehicle trajectory tracking.In the security system,the forward obstacle avoidance protection and deviation from the preset path protection are designed.Through the management center to achieve real-time vehicle status monitoring and vehicle control.Finally,the whole intelligent driving system is verified by experiments.The experiment is divided into three stages: The first stage,campus environment simulation vehicle test.Building a model car for intelligent driving test,the control system of the model car is basically the same as that of the real car.The proposed control method is verified and improved with the model car,and then transferred to the real car for simulation verification when the model car meets all the requirements of intelligent driving.In the second stage,we test the real car in plant.In the third stage,the construction field test was carried out at the high-speed Heguan section of G1511.The field experiment results verify the effectiveness of the intelligent driving system,and the horizontal control accuracy reaches ±5CM,which fully meets the requirements of the construction.