Trajectory Tracking Control Of Cartesian Coordinate Robot

In recent decades,the country has vigorously developed science and technology,and under the influence of industry 4.0,robots have been widely used in all walks of life.However,in the application process,there are some problems,such as the difficulty in manufacturing precision parts,low control accuracy and high overall cost,for which a large amount of funds and technologies have been invested in China to solve these problems.The robot control system is a complex system with nonlinear,multi-variable,strong coupling and unknown disturbance.In order to improve the system control precision and reduce the manufacturing cost,as well as the disturbance has stronger robustness,on the basis of the robot dynamics model was constructed in this paper,starting from the engineering cross coupling model and contour error,combined with the advantages of sliding mode control design of the controller and the observer,rectangular coordinate robot trajectory tracking control are studied.The specific research contents are as follows:Firstly,this paper introduces the structure of cartesian coordinate robot,and analyzes the complicated derivation and interdisciplinary problems in modeling such robot in recent years.Therefore,this paper approximates the mechanical mechanism of the robot,simplifies its derivation process,and constructs its dynamic model by using Lagrange method,paving the way for future research.Secondly,in order to increase the overall coordination of the three axis robot trajectory tracking,avoid multi-axis synchronization of component damage,at the same time to improve the control performance,the sliding mode control and synchronization of cross coupling control combination,each axis tracking error and the error between axis formed cross coupling system error,a synchronous sliding mode tracking controller is designed,and through the three axis tracking control,synchronization error,and the tracking error,compared with the linear sliding mode control,the control performance,the improvement of the overall had certain simulation proved the superiority of the method.Thirdly,since sensors are used to collect the positions of each axis of the robot,the manufacturing cost is increased,and the sensor components are affected by their own accuracy,which will also affect the control accuracy of the system.Therefore,in the building model on the basis of the above,design a cartesian coordinates robotic observer,the modified nonlinear expansion of traditional solves the nonlinear observer error correction function block switch and non-differentiable problem,not only to estimate the system state and disturbance has good tracking,also can be used as a feedforward,increase its immunity performance,speed up the convergence of the system,reduce the cost and improve the control precision.Finally,the concept of system contour error is introduced.Contour error model trajectory tracking is a more important performance index than trajectory tracking,which is designed from the geometric meaning.So in rectangular coordinate robot,contour error model is established,and then add the terminal sliding mode cross coupling control,design an improved double exponential reaching law,weaken the chattering,to reduce the steady-state error,each axis joined the integral compensation,make the system in three axis obtains a good effect on the overall control,simulation results also show its validity.