Disclosure of Invention
The invention aims to solve the technical problem of providing a cutting head height control method and a laser cutting machine, which have the advantages of high downward detection speed and stable control, aiming at the defects in the prior art.
The technical scheme adopted by the invention for solving the technical problem is to provide a cutting head height control method for a laser cutting machine, wherein an MTX system is arranged in the laser cutting machine, and the method comprises the following steps: step 1, controlling a cutting head of a laser cutting machine to descend rapidly by an MTX system; step 2, the cutting head descends to a detection height area of the height sensor, the MTX system receives and rapidly processes signal values fed back by the height sensor and the Z-axis encoder, and then outputs command values to control the cutting head to decelerate; and 3, repeating the step 2 until the cutting head reaches the set height and accurately stops moving.
In a further preferred embodiment of the present invention, the step 1 specifically comprises the following steps: and 11, feeding back a constant sensor value to the MTX system by the height sensor, and controlling the Z-axis motor to descend rapidly by the MTX system.
In a further preferred embodiment of the present invention, the step 2 specifically comprises the following steps: step 21, the cutting head enters a detection height area of the height sensor, the sensor value changes, and the height sensor feeds the sensor value back to the height adjusting box in real time; step 22, feeding back the actual coordinate value of the motor to a height adjusting box by a Z-axis encoder; step 23, the height adjusting box performs PI processing on the sensor value and the actual coordinate value of the motor to obtain a result feedback value, and the result feedback value is fed back to the MTX system; step 24, the MTX system rapidly processes the result feedback value by using the FA function and outputs a motion control command value to the Z-axis driver; and 25, controlling the Z-axis motor to perform downward deceleration motion by the Z-axis driver.
Still further preferred embodiment of the present invention further comprises the steps of: 26, in the movement process of the Z-axis motor, the Z-axis encoder sends a motor actual coordinate feedback value to the Z-axis driver; 27, receiving the actual coordinate feedback value of the motor by a Z-axis driver, and judging the actual coordinate feedback value and a set value; if the actual coordinate feedback value of the motor is smaller than the set value, driving the Z-axis motor to continue moving downwards; if the actual coordinate feedback value of the motor is equal to the set value, controlling the Z-axis motor to stop moving; and if the actual coordinate feedback value of the motor is larger than the set value, giving an alarm.
In a further preferred embodiment of the present invention, the detection height area is an area between the cutting head and the plate material, and the height of the detection height area is 10 mm.
In a further preferred embodiment of the present invention, the PI processing is processing using a PID control algorithm.
It is a further preferable aspect of the present invention that the FA function is a PLC function having a high-speed scanning period, and the period scanning time is 0.5 ms.
The invention also provides a laser cutting machine, which is used for realizing the cutting head height control method, and comprises a cutting head, a height sensor, a height adjusting box, an MTX controller, a Z-axis driver, a Z-axis motor and a Z-axis encoder which are arranged in a machine body, wherein the height sensor feeds back a sensor value to the height adjusting box until the cutting head reaches a set height value, and the Z-axis encoder feeds back an actual coordinate value of the motor to the height adjusting box and the Z-axis driver; the height adjusting box performs PI processing on the original sensor value and the actual coordinate value of the motor to obtain a result feedback value and feeds the result feedback value back to an MTX system in the MTX controller; the MTX system in the MTX controller utilizes the FA function to quickly process the result feedback value and outputs a motion control command value to the Z-axis driver; and the Z-axis driver controls the Z-axis motor to perform downward deceleration movement.
Further preferred embodiments of the present invention are: the height sensor is a capacitive sensor.
Further preferred embodiments of the present invention are: the Z-axis motor is a servo motor.
The invention has the advantages that after the cutting head begins to descend, the cutting head is controlled to descend rapidly through the MTX system, and compared with the traditional slow descending mode, the time consumed by the stroke is greatly reduced; when the cutting head entered into and surveyed the high region, the signal value of coming to height sensor and Z axle encoder feedback through the MTX system carries out rapid processing, feeds back out signal control cutting head speed reduction again, compares traditional numerical control system, and the treatment effeciency and the control accuracy of MTX system are higher, and the problem that the board was pounded in the cutting head run position has been avoided in its accurate stable control to the effect that the cutting head was not only quick but also stable from descending to the stop process has been reached.
Detailed Description
The present invention will be further described with reference to the following examples.
The MTX system used in the examples of the present invention is available from bosch corporation, which is collectively known as the indramotiontx system, and is available from conventional commercial sources.
Referring to fig. 1 and 2, a method for controlling the height of a cutting head is used for a laser cutting machine, wherein an MTX system is arranged in the laser cutting machine, and the method specifically includes the following steps:
step 1, controlling a cutting head of a laser cutting machine to descend rapidly by an MTX system;
step 2, the cutting head descends to a detection height area of the height sensor, the MTX system receives and rapidly processes signal values fed back by the height sensor and the Z-axis encoder, and then outputs command values to control the cutting head to decelerate;
and 3, repeating the step 2 until the cutting head reaches a set height value and accurately stops moving.
Preferably, the detection height area is an area between the cutting head and the plate material, and the height of the detection height area is 10 mm. The actual height value can be changed according to the use requirement.
Specifically, referring to fig. 3, the step 1 specifically includes the following steps: and 11, starting height control, feeding back a constant sensor value to the MTX system by the height sensor, and controlling the Z-axis motor to descend rapidly by the MTX system.
In this embodiment, the height sensor is a capacitive sensor mounted on the cutting head. Since the cutting head just begins to descend, the height of the cutting head is much greater than the detection height range of the height sensor. Therefore, the sensor value sent by the height sensor is a constant voltage value, and the constant voltage value is subjected to PID control algorithm in the height adjusting box to obtain a result feedback value which is fed back to the MTX system. And then, the FA function of the MTX system is utilized to rapidly process the data performance, and the Z-axis motor is controlled to drive the cutting head to rapidly descend to a detection height area. Compared with the traditional medium-low speed descending mode, the quick descending mode greatly reduces the travel time consumption.
Referring to fig. 4 together, after the cutting head descends to the detection height area in step 11, the deceleration is started, as shown in steps 21 to 25: when the cutting head enters a detection height area of the height sensor, a sensor value (namely a voltage value) fed back by the capacitance sensor changes, the height sensor feeds back the sensor value to the height adjusting box in real time, and the shaft encoder feeds back an actual coordinate value of the motor to the height adjusting box. And then the height adjusting box performs PI processing on the sensor value and the actual coordinate value of the motor to obtain a result feedback value. The height adjusting box feeds back the result feedback value to the MTX system, the MTX system utilizes the FA function to process the result feedback value quickly, the FA function processes real-time data in the high-speed data transmission process and outputs a motion control command value to the Z-axis driver, and the Z-axis driver controls the Z-axis motor to perform downward deceleration motion after receiving the control command value. And (5) repeating the steps 21 to 25 until the cutting head reaches the set height and stops moving accurately.
The PI processing is performed by using a PID control algorithm, and the principle thereof is not described herein. The FA function is Fast Action in the whole course, is a PLC function with a high-speed scanning period in an MTX system, has the period scanning time of 0.5s, can process preset or externally-transmitted data in 0.5s, and can output a command value to control the movement of a target axis.
Through the FA function of the MTX system, a result feedback value fed back in real time in the motion process of the cutting head is quickly processed, the distance between the cutting head and the plate is further determined, and a motion control command value is output to the Z axis, so that the effect that an NC-like sending interpolation command generally controls a single axis through a PLC is achieved, and the control precision and efficiency can reach the precision and efficiency of NC control. Compared with a traditional numerical control system, the MTX system is higher in processing efficiency and control precision, high-speed, accurate and stable movement of a Z-axis motor is achieved, and the problem that the cutting head runs and smashes a plate is avoided.
Further, referring to fig. 5, the cutting head height control method of the present embodiment further includes a guard step for preventing the cutting head from running out of position. As shown in step 26 and step 27, during the movement of the Z-axis motor, the Z-axis encoder sends a motor actual coordinate feedback value to the Z-axis driver, and the Z-axis driver receives the motor actual coordinate feedback value and then determines the motor actual coordinate feedback value with a preset set value. If the actual coordinate feedback value of the motor is smaller than the set value, the cutting head is not lowered to the stop position, and the Z-axis motor needs to be driven to continue moving downwards; if the actual coordinate feedback value of the motor is equal to the set height value, the cutting head is lowered to the stop position, and the Z-axis motor is controlled to stop moving; and if the actual coordinate feedback value of the motor is greater than the set height value, the cutting head is beyond the stop position, and then an alarm is given.
The invention also provides a laser cutting machine (not shown) for implementing the cutting head height control method as described above. Specifically, the laser cutting machine comprises a cutting head, a height sensor, a height adjusting box, an MTX controller, a Z-axis driver, a Z-axis motor and a Z-axis encoder, wherein the cutting head, the height sensor, the height adjusting box, the MTX controller, the Z-axis driver, the Z-axis motor and the Z-axis encoder are arranged in a machine body. The height sensor feeds back a sensor value to the height adjusting box until the cutting head reaches a set height value, and the Z-axis encoder feeds back an actual coordinate value of the motor to the height adjusting box and the Z-axis driver; the height adjusting box performs PI processing on the original sensor value and the actual coordinate value of the motor to obtain a result feedback value and feeds the result feedback value back to an MTX system in the MTX controller; the MTX system in the MTX controller utilizes the FA function to quickly process the result feedback value and outputs a motion control command value to the Z-axis driver; and the Z-axis driver controls the Z-axis motor to perform downward deceleration movement.
Preferably, the MTX controller is an MTXL75 controller, and the Z-axis motor is a servo motor. The specific model can be selected and replaced according to the actual production requirement.
It should be understood that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features; and all such modifications and alterations are intended to fall within the scope of the appended claims.