Question 1: How to choose the servo motor control mode? Generally, servo motors have three control modes: speed control mode, torque control mode, and position control mode.
If you have no requirements for the speed and position of the motor, as long as you output a constant torque, of course, use the torque mode. If there are certain accuracy requirements for position and speed, and the real-time torque is not very concerned, it is not very convenient to use torque mode, and it is better to use speed or position mode. If the upper controller has a better closed-loop control function, the speed control effect will be better. If the requirements are not very high, or there is basically no real-time requirement, there is no high requirement for the upper controller by position control.
In terms of the response speed of the servo drive, the torque mode is the smallest operation, and the driver responds the fastest to the control signal; Position mode is the most computationally intensive, and the driver is the slowest to respond to control signals. When there are relatively high requirements for dynamic performance in motion, it is necessary to adjust the motor in real time. Then if the computing speed of the controller itself is very slow (such as PLC, or low-end motion controller), use position control. If the controller computing speed is relatively fast, the position ring can be moved from the drive to the controller in a speed way to reduce the workload of the drive and improve efficiency (such as most high-end motion controllers); If there is a better upper controller, it can also be controlled by torque, and the speed ring is also removed from the drive, which is generally only a high-end special controller can do this, and there is no need to use a servo motor at all.
In other words: 1, torque control: torque control mode is through the input of external analog or direct address assignment to set the size of the external output torque of the motor shaft, specifically manifested as 10V corresponding to 5Nm, when the external analog quantity is set to 5V, the motor shaft output is 2.5Nm: if the motor shaft load is lower than 2.5Nm, the motor does not rotate when the external load is equal to 2.5Nm, and the motor reverses when it is greater than 2.5Nm (usually generated in the case of gravity load).
The set torque can be changed by changing the setting of the analog quantity in real time, and the value of the corresponding address can also be changed by communication. The application is mainly in the winding and unwinding devices with strict requirements for the force of the material, such as the wire device or the optical fiber pulling equipment, the torque setting should be changed at any time according to the change of the radius of the winding to ensure that the force of the material will not change with the change of the winding radius.
2. Position control: The position control mode is generally determined by the frequency of the external input pulse to determine the size of the rotation speed, and the angle of rotation is determined by the number of pulses, and some servos can directly assign the speed and displacement through communication. Since the position mode can have a very strict control of speed and position, it is generally used in positioning devices. Application fields such as CNC machine tools, printing machinery and so on.
3. Speed mode: the rotation speed can be controlled by the analog input or the frequency of the pulse, and the speed mode can also be positioned when the outer loop PID control of the upper control device is controlled, but the position signal of the motor or the position signal of the direct load must be fed back to the upper level for calculation. The position mode also supports direct load outer loop detection position signal, at this time the encoder at the motor shaft end only detects the motor speed, the position signal is provided by the direct final load end detection device, which has the advantage of reducing the error in the intermediate transmission process and increasing the positioning accuracy of the entire system.
Problem 2: How to make the servo motor turn up Hello, to make the servo motor turn up, you need a servo controller (to match the servo motor), and wire it according to the terminal diagram on the servo controller manual. If you want to use pulse control, there is also a PLC plus program (high-speed output program).
If it is controlled with analog, it is relatively simple, as long as it is enabled to be connected, there is no emergency stop signal, forward or reverse signal, no forward or reverse limit, a signal input between 0-10V is given. However, this basically has no great practical application value, and now most of them use PLC to control the servo controller and then drive the motor, or synchronous operation, there is a master and slave, actively controlled by PLC, and the driven works according to the motor encoder signal fed back by the active motor.
Novices should first look at the manual of the servo controller to understand. I hope my answer is helpful to you