Research On Pid Control Of Mechanical Joints With Two Inertial Characteristics

In the current industrial generation,Robot arm is known as "the pearl on the crown of manufacturing industry".It can be seen that its position in production equipment,as an automation equipment,covers a variety of disciplines such as machinery,electronics and other knowledge,is an important symbol of a country's productivity level.With the continuous development of the mechanical arm,the mechanical arm or mechanical joint is developing towards high precision,light miniaturization and high speed.In order to realize high precision,light and miniaturization and high speed of two-degree-of-freedom joint,the structure and theory are studied respectively in this paper.Firstly,for the high precision requirement of mechanical joints,the structure selection and hardware planning of 2-dof joints are carried out.Firstly,double motor clearance is used to reduce the influence of two inertia characteristics;Then the hardware planning diagram of the single joint controller is given according to the clearance elimination mode;At last,the strength and deformation of the joint were analyzed,from the analysis,it can be seen that the improvement of the structure alone is far from meeting the requirements of high precision joint drive,but also must take corresponding measures in the control.Secondly,aiming at the high precision requirement of mechanical joints,the control mode of mechanical joint is studied theoretically in this paper.In order to realize the engineering application of mechanical joints,the new control algorithm is obviously unable to achieve,in this paper,the classical PID control algorithm is analyzed,in order to obtain a system parameters depend on the less way of setting.First,the engineering tuning formula of PID parameters is deduced;Then the simulation of parameter setting in frequency domain is carried out based on the joint model with two inertial characteristics,and the empirical setting formula under certain constraints is obtained;Finally,the system dependence of the two methods is compared,which shows that the empirical formula method has weak system dependence.Then,according to the light and small requirements of mechanical joints,the light and small motor system is designed.Firstly,the structure of the motor body is designed,and the high-speed and heavy-duty motor structure that meets the requirements of the index is obtained.Through electromagnetic simulation,the designed structure is verifiedand modified;Then according to the high-speed requirements of the motor,the motor controller hardware design and theoretical analysis were completed,the theoretical dead time of the designed controller is analyzed,and the possibility of high frequency of the selected device is verified;Finally,the combined magnetoelectric encoder is designed in order to realize the structure of electric gap elimination,In order to realize high precision transmission of mechanical joints,a high precision encoder is designed preliminary.Finally,basic experiments and parameter setting experiments are carried out.In the basic experiment,the function of the designed high frequency controller is first verified,and the theoretical dead zone is verified;Then the multi-polar program used in high precision encoder is verified,and the calibration result verification experiment and dynamic servo precision experiment are carried out.In the parameter setting experiment,the parameters of the specific experimental platform are calculated according to the two parameter setting methods,and the simulation and correction are carried out;Then,the field trial and error method is used to make the motor system work stably,and in this process,the influence of dead zone time on the temperature rise of the motor is verified;Finally,the effects of the three tuning methods on system stability are compared.