Research And Implementation Of Positioning Accuracy Compensation Technology For Industrial Robot

The positioning accuracy of industrial robot is divided into absolute positioning accuracy and repetitive positioning accuracy.The absolute positioning accuracy of industrial robots is low,which leads to the problem of large deviation between the desired position and the actual position in the process of off-line programming,and the problem needs to be solved urgently.On the basis of analyzing the existing domestic and international positioning accuracy compensation technology,this paper will focus on the problem of parameter error identification accuracy and suiting for fast compensation method in the industrial field.With six DOF industrial robot as the research object,the compensation method proposed will be discussed and be validated with experiment.The research is of great significance to promote the transformation and upgrading of the manufacturing industry.The main work and research of this paper are as follows:A geometrical parameter calibration method based on IEKF is proposed,aiming at the problem that the industrial robot positioning accuracy is low due to the inaccurate geometric parameters.By establishing the geometric parameters error model,the parameter Jacobian matrices are constructed by vector product method,and IEKF algorithm is used to expand the nonlinear function of measurement equation repeatedly with Taylor to reduce the linearization error,and the observation vector is modified dynamically in the process of it.Finally,the nominal values of geometric parameter are corrected by the identified geometric parameter errors.The experimental results show that the IEKF algorithm improves the average error and the standard deviation by 83.30% and 82.61% respectively,and the accuracy of the identified geometric parameter is significantly higher than that of standard EKF and LM-LS algorithm,which verifies the proposed method.Aiming at the problems that the traditional measuring equipment is expensive and complex and not suited for fast compensation in the industrial field,with the research of the traditional PSD calibration method is launched,a geometric parameter calibration method based on PMPSD is proposed.Through the establishment of space more virtual constraint model,the pose modified principle is proposed to correct the laser transmitter's pose and the robot's joint angles,and the geometric parameters errors are obtained by using the LM algorithm to optimize the model constraint object function,which effectively improve the efficiency of calibration.The experimental results show that the PMPSD calibration method can avoid the PSD feedback control,and it can calibrate the geometric parameters quickly.The correlation between the geometrical parameter errors obtained and the data obtained from IEKF algorithm and the traditional PSD calibration method is 0.8877 and 0.9488 respectively,which has a high correlation,and the average error and the standard deviation are improved by 78.28% and 76.38% respectively,further verifying the effectiveness of the proposed method,which has certain utility in the engineering.The positioning accuracy compensation technology of the industrial robot is researched and improved from two aspects of the parameter error identification accuracy and calibration efficiency.Above comprehensive analysis,the geometrical parameter calibration method based on IEKF has a better compensation effect,which is suitable for requiring high positioning accuracy requirements of industrial application,and the geometrical parameter calibration method based on PMPSD is suitable for high requirements of calibration efficiency and positioning accuracy of industrial environment.The two compensation methods proposed can improve the positioning accuracy of the industrial robots.