A method for calculating the influence of slag splash on capacitance sensor is proposed by using a finite element method to solve the problem that the capacitance sensor detection signal of the position detection system is susceptible to the influence of cutting slag in the laser cutting process. Firstly

a model for the sensor is built through COMSOL software

and the finite element method is used to simulate the capacitance change of the capacitive sensor and the influence of various factors on the effect of the capacitance during the slag splash process. Secondly

metal balls are used to simulate molten slags and to verify the simulation results. Finally

an interpolation method is used to process the simulation results and the measured capacitance

and an isoline map of capacitance is drawn to obtain the change rule of capacitance in the process of slag sputtering:Capacitance change is characterized by gradual increasing and two mutations in the process of slag moving towards the cutting head

while the size of the change is directly proportional to the volume of the slag and has an inverse relationship with the spacing of the plates. Moreover

the slag has great impact on sensors when it is in the plane affected area and the lower area. Experimental results show that the error between the measured value and the simulation result is less than 0.001 pF

the simulation results accurately reflect the interference of slag splash to capacitance sensor

and provide a theoretical basis for interference filtering and cutting head design.