Synchronous Belt Type XY Servo Mechanism Error Compensation Method

As a common motion control system,because XY servo mechanism of synchronous belt has servo functions such as being able to achieve accurate positioning based on the expected trajectory and given motion parameters or follow a specific rule curve to complete track tracking,it has been widely combined with the measurement system to form new measurement means But in the manufacturing,assembly,control and movement process,the transmission error of servo system will be made because of friction,inertia,thermal deformation and so on.The paper proposes the method of multi-image forward intersection based on exterior elements solution and RBF neural network to detect the transmission error,and model the error data by using the polynomial fitting method.Finally,the error compensation of the servo mechanism is carried out,and the effectiveness of the method is verifiedThe existing error compensation of synchronous belt XY servo mechanism are mostly made by using the expensive special equipment to detect error,and from the point of view of mechanics,rigid body kinematics or machinery to establish the error model.The main problem is that,first of all,it is difficult to establish the error model precisely because it is difficult to get the specific error factors.Secondly,the error model with mechanical,rigid-body kinematics or mechanical has more parameters and more complex calculation.In view of the above problems,this paper takes the two-axis motion controller controlled by the PCI-1240U4 control card as the research object,from the perspective of photogrammetry,restore the motion track of the synchronous belt XY servo mechanism to realize the error detection,and use the polynomial fitting method to model the error of the multi-group error data.To recover the motion trajectory,the spatial point sequence of the calibration plate moving along the synchronous belt XY servo mechanism is restored by the multi-image forward intersection.In order to enhance the solving accuracy of spatial point which is influenced by the camera parameters and a series of factors in the imaging process,considering the optimization of the exterior elements of the camera,and constructing the RBF neural network to correct the multi-image forward intersection results to achieve the precise spatial point positionThis method is applied to the servo mechanism to implement the work of detecting、modeling the error of transmission,and the model is applied to the error compensation.The method is evaluated on the basis of error reduction and positioning accuracy after compensation.The experimental results show that this method can effectively compensate the transmission error of synchronous belt XY servo mechanism,and the transmission error of X-axis and Y-axis is reduced by 94.58%and 98.21%after compensation,respectively.And sub-mm level servo system positioning can be achieved.