Synchronizing stepper motors and servo motors is essential for achieving precise motion control. Motor synchronization refers to the coordinated control of multiple motors to maintain consistent and accurate motion. This capability is critical in automation applications such as robotics and CNC machine tools.
Below are several common methods for synchronizing motors.
1. Pulse Synchronization
Pulse synchronization controls the coordinated motion of multiple motors by sending synchronized pulse signals. This method is widely used with both stepper motors and servo motors.
Synchronization Mechanism
The controller sends pulse signals to multiple motors simultaneously, ensuring that the pulse frequency received by each motor is identical, thereby achieving synchronous motion.
When applied to stepper motors, there are two common wiring configurations:
- One driver driving two motors. For example, the DM456AI driver can drive two motors simultaneously while maintaining synchronization.
- One controller feeding two identical stepper drivers, each connected to an identical motor. A drawback of this approach is that it requires more installation space.
Characteristics
- Simple to implement; suitable for low-speed, small-scale applications. Pulse synchronization is effective for synchronization widths up to 1.5 m.
- Positional deviation tends to be relatively large, making this method better suited for flexible gantry applications that can tolerate a certain amount of deviation.
2. Frequency-Division Output Synchronization
Some servo motors provide a frequency-division output function that can be used for synchronization. This method is particularly useful when the controller cannot provide two independent pulse outputs.
For example, connecting the CN1 encoder frequency-division output (A+, A−, B+, B−) of one A6 servo drive to the pulse input of another A6 servo drive will cause the two units to run synchronously.
Characteristics
- The basic principle is the same as pulse synchronization: simple to implement and suitable for low-speed, small-scale applications.
- Positional deviation tends to be relatively large, making this method better suited for flexible gantry applications that can tolerate a certain amount of deviation.
3. CANopen and Other Fieldbus Protocols
The CAN bus (Controller Area Network) is a widely used communication protocol, especially suited for real-time control and monitoring applications. Using a CAN-based fieldbus to synchronize servo motors is both efficient and reliable.
System Design
- Controller selection: Choose a servo drive that supports CAN bus communication to ensure it can process synchronization commands and feedback data.
- Network topology: Design an appropriate network topology—such as a line (bus) or star topology—to ensure stable signal transmission.
Synchronization Strategies
- Basic synchronization: The master controller sends a synchronization command, and each servo motor begins moving simultaneously upon receiving the command. This approach is suitable for straightforward synchronization requirements.
- Precision synchronization: Using real-time feedback data, the master controller continuously adjusts the operating state of each motor to compensate for load variations and dynamic conditions, ensuring high-precision synchronous control.
4. High-End Servo Packages with Built-in Gantry Synchronization
Some high-end servo motor packages include a built-in gantry synchronization function. Please note that STEPPERONLINE does not currently offer products with this feature.