Independent Mining Trajectory Planning And Control System

There were three problem needed to be covered for automatic digging of excavatorrobot, it’s how to get target pose and current pose, then the design of control system. So,aimed at building a closed cycle control system, these three problem were analysised in thispaper.Using Matlab to plot the workspace of excavator robot,and according to excavator’sworking features, a trapezoidal area was found in the workspace of excavator robot, thentask planning during the trapezoidal was done based on planning rules and skilled operator’sexperience. The whole process of single digging cycle using bucket to dig was introduced inthis paper.Finally, a3-D model was built in Proe and a point V was settled in bucket’s teeth,and the function of machanism analysis in proe was used to measure point V’s componentmotion in X, Y, Z direction during the process between finishing point and the next freshbeginning point. The measurement data was exported into a Excel file, matlab was used toextract these data to plot the trajectory of point V in3-D space. And the Excel file couldalso be used as controlling signal during following trajectory tracking task.Model of working device of excavator robot was built in D-H coordinate system,variation of coordinates method was chosed to cover inverse kinemetic problem, andanalytical and geometric method was chosed to cover forward kinemetic problem. Ageometric model of working device of excavator robot was also built to cover the problemof transformation between joint angular space and driver space.Displacement sensor was used to measure the displacement of excavator robot’s boomcylinder, stick cylinder and bucket cylinder, together with the result got by kinemeticanalyse, this measurement system could replace the measurement project that using encoderto dectect the angular of each joint angle, and this dectect system could offer more realiablepose for following trajectory tracking even in terriable environment out door.Because the hydraulic system of excavator was too complex to built a accuratemathmetic model for it, so a proffional soft ware for hydraulic or other complex system indifferent fild was chosed to built model for hydraulic excavator robot’s working device.Both advantage and disadvantage of PID and Fuzzy control were analysed, and a project chosed self-tuning PID controller based on fuzzy inference was selected as a controller tocover trajectory tracking task. This controller was designed in matlab-simulink with Fuzzytoolbox in matlab. Finally, a cosimulation in AMESim and Matlab-simulink was donetoanalyse boom’s hydraulic system reponse to step signal, square wave and square wavewith interference signal, from the result from the analysis verified the self-tuning PIDcontroller based on fuzzy inference designed in this paper had a very well adaptiveness andRobustness.