The action functions f1 and f2 are taken as hyperbolic tangent and linear functions, respectively. For the network shown, it can be derived: 5dk5Ti=2NHj=1<1-f21(Xj)>W1(j,i)W2(k,j)(1) where xj=2NIi=1TiW1(j,i)+b1 (j) The running identification program can obtain the parameters W1, b1, W2, b2 of the temperature rise and displacement network model and the partial derivatives calculated according to the formula (1), and output the key points of the thermal deformation in order. The example is the arrangement of the temperature measurement point and the displacement point of the outer surface of the vertical machining center. 21, 22, 23 and 24 points are arranged in the inner and inner surfaces of the headstock, the oil tank and the coolant tank, respectively. Experiments show that there is an approximate relationship between the temperature rise of the temperature measurement point of the machine tool and the time t: $T=Ts(1-et/Tc)(2) where the temperature rise of Ts reaches the thermal equilibrium Tc time constant experiment shows that the machine tool is continuous The heat balance is basically reached after 6 hours of operation. The machine was stopped for more than 6 hours before measurement, and then the machine was continuously operated under no-load conditions. The displacement of the front end of the spindle at the measurement points in the X and Y directions was measured every 20 minutes. The results were recorded and started at the beginning of the experiment. The temperature at each point was measured at 1 hour and 6 hours, and the points Ts and Tc were calculated based on this, and the calculation results were recorded. Using the data and formula (2), the temperature rise value of each temperature measurement point every 20 minutes can be calculated to form a network input sample, and the training sample composed of the sample and the given target vector is input to the identification program. For the program running result, the serial number is sorted by the partial derivative from large to small, and the first three digits are measured. Point 21 is the inner cavity of the spindle box, and its temperature rise is a comprehensive reflection of the temperature rise of the main motor, the main shaft components and the transmission system. Point 16 is the front end support of the main shaft, where the speed is high and the friction is large, and the thermal deformation caused thereby is directly Affect the processing accuracy. The area at these two points has the largest influence on the thermal displacement in the X and Y axis directions, so it is the key point of the thermal deformation of this machine tool. It should be used as the temperature measurement and temperature control point to minimize the temperature measurement point and temperature control point. The best results. (Finish) Land Subsoiler,Farm Subsoiler,Subsoil Cultivator,Agricultural Subsoiler JINING TIANDE ENGINEERING MACHINERY CO.,LTD , https://www.tdgoldargo.com
A Brief Analysis of the Key Areas of Thermal Integration of CNC Lathes
W1, b1 and W2, b2 are the input layer and hidden layer and hidden layer and output layer network parameters respectively, f1 and f2 are the function functions of the hidden layer and the output layer respectively. Identify the process flow for key points. The medium training parameters include: display frequency, maximum number of trainings, target error, initial learning rate, incremental multiplication factor, decrement multiplying factor, momentum factor, and error rate.
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