How to solve the inaccuracy of the positioning system in the laser engraving machine?

1. The general stepper driver has certain requirements for direction and pulse signal. For example, the direction signal is on the rising or falling edge of the first pulse (different driver requirements are different, several microseconds are determined before arrival, otherwise it will There is a pulse running at the opposite angle to the actual required steering. Finally, the fault phenomenon appears to be more and more biased, and the smaller the subdivision is, the more obvious the solution is. The solution mainly uses software to change the logic or delay of the pulse.

2, due to the characteristics of the stepper motor determines that the initial speed can not be too high, especially with a large load inertia, it is recommended that the initial speed is below 1r / s, so the impact is small, the same acceleration is too large, the impact on the system is also large, easy to The punching causes the positioning to be inaccurate; there should be a certain pause time between the forward and reverse rotation of the motor, and if not, the overshoot will be caused by the reverse acceleration being too large.

3. Adjust the value of the compensated parameter according to the actual situation. (Because the elastic deformation of the synchronous belt is large, it is necessary to add some compensation when changing the direction.

4. Appropriately increase the motor current and increase the driver voltage (note that the driver is selected and the motor with larger torque is selected.

5, the system's interference caused the controller or driver's malfunction, we can only find ways to find the source of interference, reduce its interference ability (such as shielding, increase the separation distance, etc., cut off the transmission path, improve their anti-interference ability, Common measures:

(1) Replace the ordinary wire with a double-shielded shielded wire. The signal wire in the system is separately routed from the high-current or large-voltage-changing wire to reduce the electromagnetic interference capability.

(2) Use the power filter to filter out the interference wave from the power grid. Under the condition of permission, the power supply filter is added to the input end of each large power equipment to reduce the interference between the equipments in the system.

(3) It is better to use the optical isolation device for signal transmission between the devices. Under the condition of permission, the pulse and direction signals are preferably transmitted by differential mode plus photoelectric isolation. Inductive loads (such as electromagnetic relays, solenoid valves, both ends plus RC absorption or fast bleeder circuits, inductive loads can generate 10 to 100 times the peak voltage at the beginning, if the operating frequency is above 20KHZ.

6. The software does some fault-tolerant processing and eliminates the effects of interference.