Analysis And Development Of An Unmanned Tandem Road Roller

An unmanned road roller has become an attractive solution for reducing operator labor and improve compaction efficiency.That is why,today,many scientific institutions are dedicated to the development of unmanned construction machines.One of the most perspective machines is the road compactor.Pavement compaction quality is mainly monitored by the detection instruments in the operator’s cab and other indicators that transmit information from the installed sensors(acceleration vibration sensor,temperature sensor,positioning system,speed sensor,etc.).However,relying on the operator to control compaction parameters may be a problem of undercompaction,over-compaction,or re-compaction between adjacent work surfaces.Besides the human factor,some technologies for checking the quality of pavement compaction,do not meet today’s standards,and also lead to local damage to the pavement.One of the best solutions to this problem is a robotic road roller with integrated compaction quality control system.This system consists of two interrelated levels,the first is the plotting of the desired work area,and the second is,as the robot moves along the working route,to create a map of pavement compaction quality.The other subsystems are responsible for controlling the road roller’s motors,adjusting speed,determining the direction of travel,and most importantly for robotic machines is identifying obstacles and avoiding them.To carry out scientific work,many sensors and tests are needed.It is necessary to study precise positioning systems and the theory of road compaction.The main sensors for creating a monitoring and compaction control system are a GPS module and an accelerometer.There are also many necessary sensors,without these parts the work of the robot is impossible.These are sensors such as an electronic compass,ultrasonic sensors,communication system,power control modules and others.To achieve the objectives,a plan was developed consisting of several steps:1.Based on scientific experience and the working area of the developed machine,the basic dimensions of the road roller were calculated.In addition,the basic elements necessary to maintain the operation of the road roller have been calculated.Such as engine,steering mechanism(hydraulic steering cylinder),eccentric vibrating wheel and others.2.In accordance with the theory of vibration and compaction of materials,calculations were made to establish the relationship between the vibration frequency of the steel wheel of a road roller and the signal received from the acceleration vibration sensor.The resulting formula allowed establishing relationship between the frequency of vibration and the degree of compaction of the pavement3.Taking into account the structure and size of the road roller,kinematic calculations were made.A simulation of the roller motion in forward and inverse kinematics modes was carried out.4.To conduct the experiments,the model structure of a road roller is composed,which includes many sensors to control the driving,positioning and quality of the compacted material.5.Based on the calculations made and the data obtained from the acquisition board,a program was written in the Java language to monitor the operation of the robotic road roller.The resulting program allows the user not only to see in real time the quality of compaction and the traveled route,but also to give commands for execution,such as sending coordinates and plotting a new path.The results show that based on accurate coordinates and calculation,it is possible to design and program a road roller as an unmanned device.The created route of the road roller is able not only to drive a road roller,but also,when working together with an acceleration vibration sensor,to analyze the quality of the work being done.Real-time monitoring of the compaction process solves the disadvantages of the traditional method of testing and determining the quality of compaction,such as large sampling randomness and poor real-time performance.And the automatic control system removes the human factor and saves time by eliminating errors.Therefore,technicians are able not only monitor the machine’s position on the ground,but also make adjustments to the driving route.All these innovations not only reduce the wasted time,but also increase the quality of the work,as well as work conditions.