Design Of Flexible Grinding Terminal Actuator System

Grinding plays an important role in the field of industry.With the development of science and technology,the grinding method is developing towards automation and intelligence.In the grinding process,the grinding quality can be effectively improved by maintaining the uniformity of the grinding quantity,and the grinding quantity can be controlled by controlling the grinding contact torque between the grinding tool and the workpiece surface.This design proposes a single-degree-of-freedom electrical drive flexible grinding terminal actuator based on the impedance control algorithm.The main contents are as follows:(1)By comparing the differences and characteristics of different grinding operation modes,the development status and trend of robot compliant grinding terminal actuator at home and abroad are analyzed,and a single degree of freedom compliant grinding terminal actuator is proposed.Based on the plane grinding method,the grinding model is established,and the overall functional requirements and technical indicators of the system design are put forward,including the functional requirements of mechanical structure and software and hardware.(2)According to the functional requirements of the mechanical structure,the mechanical structure is designed,including displacement adjustment mechanism,sliding table and grinding mechanism.According to the structure parameters,the sliding table,grinding DC motor and axial drive servo motor are selected.According to the requirements of hardware function,select the hardware function module and build the experimental platform.(3)The position based impedance control algorithm is selected by comparing the force/ position hybrid control algorithm with the impedance control algorithm.The control model of compliant grinding terminal actuator is proposed,including position control module based on trapezoid speed planning algorithm,grinding motor speed measurement module,real moment extraction module,moment conversion module,PID control module and impedance control module.(4)According to the functional requirements of the software,the modularized program is designed,and each functional module is tested separately,including measuring the angular velocity and acceleration of the grinding motor,reading the position,velocity and acceleration information of the servo motor,controlling the grinding terminal actuator to carry out the axial reciprocating motion,realizing the communication between controllers,reading the measured value of the torque sensor,and realizing the PID control calculation Method and impedance control algorithm,etc.(5)Test the influence of axial force and bending moment on the output value of torque sensor,test and analyze the static and dynamic characteristics of torque sensor.The moment of inertia of grinding tool,coupling and grinding motor shaft is calibrated,and the real grinding moment is transformed into the equivalent axial force model.Through constant force control experiment,it can be seen from the experimental results that this compliance grinding terminal actuator can provide the contact compliance between grinding tools and workpiece,and can ensure the grinding torque fluctuates in a small range.Since this design is only a single degree of freedom compliant grinding terminal actuator,in order to make this compliant grinding terminal actuator adapt to more complex working conditions,it needs to develop to the direction of multiple degrees of freedom,and at the same time,it needs to constantly optimize the structure and algorithm of the program to improve the robustness of the program.