On-machine monitoring system for failure state of rotating tool and detection method therefor

A detection method for a failure state of a rotating tool based on an on-machine monitoring system for a failure state of a rotating tool, wherein the on-machine monitoring system for the failure state of the rotating tool comprises a detector, a data processing controller, a tool data server, and a Hall current sensor, wherein

• the data processing controller is connected to the detector through a signal cable and also connected to a computer numerical control (CNC) controller, the tool data server, and the Hall current sensor;
• the Hall current sensor is configured to sense a spindle current signal;
• the detector is internally provided with a telecentric lens and a backlight source, the telecentric lens and the backlight source are configured to perform parallel projection on a tool to obtain image sequences of the tool during a rotation process of the tool, the image sequences of the tool are configured to show a variation trend of the tool in size;
• the size of the tool comprises a tool diameter and a tool length;
• the data processing controller is configured to monitor the failure state of the tool according to the image sequences of the tool and the spindle current signal;
• and the failure state of the tool comprises a wear state, a breakage state, an edge chipping state, and a breaking state of the tool;
• wherein the detection method comprises:
• step 1:
• turning on a power supply to make a kernel program in the computation module start automatically and wait for measurement, wherein the pneumatic plunger is normally closed, and the positive pressure protection is executed all the time;
• step 2:
• running a measurement macro program in a main numerical control (NC) machining program by a machine tool operator in a manner of subroutine calling, and transferring parameters during calling the measurement macro program, wherein the transferred parameters indicate a specific cross section for measurement of the tool diameter;
• step 3:
• controlling, by the measurement macro program, the tool to move to an initial detection point, wherein the initial detection point refers to a fixed position designated by a user and is located at an upper portion of the detector;
• controlling, by the measurement macro program, the tool to descend from the initial detection point to a concave measurement area in a middle of the shell, wherein a tip of the tool shields a laser beam emitted by the transmitter of the optical fiber sensor firstly during the descent of the tool to generate a step trigger signal at the receiver of the optical fiber sensor;
• sending the step trigger signal to the CNC controller of a CNC machine tool to trigger the measurement macro program to run a skip command G31;
• stopping the descent of the tool based on the skip command G31;
• and setting a first macro variable to 1 by the measurement macro program;
• step 4:
• querying a value of the first macro variable by the kernel program, and under a condition that the value of the first macro variable is 1, controlling, by the air path control module, the cleaning nozzle to be opened via the cleaning air tube to clean the tool by spraying a pressured air flow;
• otherwise, keeping waiting;
• step 5:
• controlling, by the measurement macro program, the tool to move to a detection position in front of a field of view of the telecentric lens, wherein the detection position is a focus of the field of view of the telecentric lens, and setting a second macro variable to 1 by the measurement macro program, simultaneously;
• step 6:
• querying a value of the second macro variable by the kernel program, and under a condition that the second macro variable is 1, by the kernel program, controlling the camera module to be opened and turning on the backlight source through the light source control module;
• otherwise, continuing to clean the tool;
• step 7:
• controlling, by the air path control module, the cleaning nozzle to be closed via the cleaning air tube and the pneumatic plunger to be opened via the plunger air tube, and performing the parallel projection by the camera module on the tool through the telecentric lens during rotation of the tool, to obtain the image sequences of the tool;
• step 8:
• controlling, by the kernel program, the pneumatic plunger to be closed and the backlight source to be turned off through the data processing controller, after shooting is finished, and informing, by the kernel program, the measurement macro program to control the tool to return to the initial detection point, to finish the detection;
• step 9:
• processing the image sequences of the tool, obtained by the camera module and the telecentric lens, by the kernel program to determine the tool length and the tool diameter, wherein the tool length and the tool diameter are used to determine the wear state and the breakage state of the tool;
• step 10:
• acquiring the spindle current signal by means of the Hall current sensor;
• and
• step 11:
• determining the edge chipping state and breaking state of the tool according to the spindle current signal.