Research On The Position And Attitude Measurement System Of Drilling Arm Of Rock Drilling Robot

The positioning accuracy of the traditional rock drilling robot’s arm is low,which affects the blasting effect and hole quality.Therefore,it is very important to study the measurement technology of the arm’s position and pose and improve the positioning accuracy of the arm.In order to improve the positioning accuracy of the drilling arm,the structure of the drilling arm of the drilling robot is analyzed.According to the kinematic principle of the robot,the kinematic model of the drilling arm is established by using the D-H coordinate representation method,and the kinematic equation of the drilling arm is obtained.By solving the motion equation of the drill arm,the attitude information of the end of the drill arm relative to the root position is obtained.Based on the D-H model of drilling arm,a set of position and attitude measurement system for drilling robot is designed,which mainly includes data acquisition module and data processing module.The distributed data acquisition structure is adopted in the data acquisition module.The data acqui sition and transmission of the attitude change data of the drill arm joint is completed by eight data acquisition units arranged at six groups of rotating joints and two groups of moving joints of the drill arm.The data acquisition unit adopts absolute value encoder to collect the original signal and output the digital signal directly.STM32 + CPLD dual processor structure is adopted,in which CPLD realizes the synchronous serial output interface SSI of encoder,and STM32 as the core processor controls the data acquisition unit as a whole,including the signal acquisition of encoder,power control,USB communication with upper computer,can bus communication with data processing module,etc.The data processing module mainly completes the position and attitude processing of the drilling arm,selects the high-performance STM32 embedded microprocessor design,optimizes the system structure,and provides more expansion interfaces.Based on the abundant internal resources and powerful floating-point processing ability of STM32,the position and attitude processing module of the drill arm is built in STM32,and the position and attitude processing of the drill arm is carried out according to the attitude change data of the drill arm joint collected by the data acquisition module to obtain the position and attitude state information of the end of the drill arm.At the same time,STM32 as the main CPU controls all parts of the data processing module,mainly including the power part,the serial port communication with the upper computer and USB communication,the CAN bus serial communication with the data acquisition module,the position and orientation information display function of the drill arm of OLED,etc.The experiment shows that the system designed in this paper works well in tunnel drilling.The maximum deviation between the theoretical value and the actual value in X,y,z direction is 9.60 cm,and the minimum deviation is 0.09 cm.The error range meets the technical requirements,proves that the overall performance of the system is good,achieves the design purpose,and has a certain practical value.