Research On Active Control Strategy Of Automobile Hub Grinding Robot

With the development of the robot field.It has been a general trend to use industrial robots to replace manual workers.China is a big country in automobile production and sales.At present,most of the domestic automobile manufacturing fields have used automatic production.Only the car wheel polishing operation is still via manual work.Nowadays,there are still some limitations such as high cost and unstable precision.The auto industry abandoned automation.The main factors that restrict the application of robot in automobile field.The main factor is the backward force position control system of the end-effector.Therefore,a robot active control strategy based on polishing is studied.It has very important market prospect and realistic significance.This paper aims at the requirements of grinding and polishing on the surface of automobile wheel hub.ER20 industrial robot is used to polish the wheel hub.The active submissive control method of constant pressure at the end is studied.Combined with off-line programming and real-time control,the robot grinding operation is realized.The research work of this paper is as follows:1.Compared with the research results of grinding and polishing technology of wheel hub.The wheel hub surface grinding operation is divided into block classification.The classification of concave-convex rotary surface and automobile wheel is discussed to select the appropriate end-effector.According to the corresponding end-effector to develop the corresponding grinding and throwing program.2.The kinematics of ER20 series robot is analyzed.Build the MD-H model to verify the positive and negative kinematic solutions.Verifying the workspace of ER20 to meet the requirements of hub processing.According to the processing division of the wheel hub,select the location and order of the corresponding processing points.The contact area between the end grinding tool and the processed surface of the hub is kept constant.The robot end-effector trajectory is determined according to the position and sequence of processing points.The impact optimization of robot joint acceleration is carried out by using quintuple polynomials.3.Through the contact force analysis of the grinding process of the robot end-effector.Combined with the current PID algorithm,impedance algorithm and adaptivesliding mode variable structure algorithm in machine power level control research.A control system with adaptive compensation is designed.Compensate for the offset of force and torque during the grinding process.The off-line programming software is used to generate the grinding trajectory.The trajectory of the grinding operation is adjusted dynamically in real time.Track the desired trajectory.Thus,the constant pressure grinding is realized.4.Co-simulation with ADAMS/MATLAB was used to build the simulation platform of grinding and polishing automobile wheel hub robot.Verify the effectiveness of the algorithm.The grinding and polishing platform system of automotive wheel hub robot is built.The experimental study of wheel hub polishing is carried out and the data comparison simulation results are derived.Based on the test results,conclusions and deficiencies are drawn.