Research On Compliant Grasping Technology Of The End Effector For The Pulp Felt

With the increasing intelligence and automation in industrial production,more and more robots are used in the work,and the grasping operation of the robot as a basic function faces more stringent requirements.The compliant control can adjust the controlled quantity in real time according to the feedback information of the sensor.Applying it to the robot grabbing technology is of great signifi-cance for expanding the scope of the robot,improving the grasping precision and working efficiency.In this thesis,the compliant grasping of the end effector of the robot is taken as the research background.According to the characteristics of water-containing,soft and poor consistency of the pulp felt,the compliant strategy based on the fusion of the sliding sensor and the force sensor is determined.And a further study on sliding signal recognition and controller design is carried out.The main contents of this thesis are as following:(1)According to the characteristics and actual working conditions of the pulp felt,the compliant grasping work route with the feedback of the sense of slip and force was determined.The finger part of the end effector was designed,and the test platform of the smooth gripping system was built in the laboratory.(2)The sliding signal during the picking process of the pulp felt is recognized.Based on the characteristics of the new piezoelectric material PVDF film,a sliding signal recognition algorithm based on simplified integral is proposed for the coupling of tactile and sliding signals.The sliding sensor module was designed and tested to verify the feasibility of the algorithm,and the sliding threshold was determined to be 40%.(3)Active compliant controller is designed.On the basis of industrial PID control,a nonlinear PID controller is designed by combining with nonlinear theory and stability analysis.After creating nonlinear constructor of the integral and differential links,the feasibility of the new controllor is verified by simulation of MATLAB/Simulink.(4)The development of compliant grasp strategy and experimental verification.Based on the combination of sliding and force sensors,a compliant grasp strategy and workflow were developed for the grab test.The comparison results show that the nonlinear PID controller has higher success rate and better control performance than the linear one when grabbing non-rigid body,which verifies the practical value of the active compliant controller designed in the subject.The grasping strategy and the compliant controller in the soft gripping technology of pulp felt are studied in this thesis,which provids technical support for the loading and unloading robot in the actual project.Also exists certain reference value for the grasping operation of other industrial robots.