Combined with the Servo control scheme with Stepper motor characteristics, the Stepper Servo Motor technique can enable the stepper motor to perform better performance and replace servo applications of the same power.
Hence Stepper Servo Motor is the most cost-effective option for automatic equipment.
Why Stepper motors’ performance is so important?
The stepper motors move in precisely repeatable steps, hence they are the motors of choice for machines requiring precise position control in applications like CNC Milling, CNC Lathe, CNC Router, etc.,
What are CNC Machines?
CNC stands for Computer Numerical Control. CNC Machine is a machine with a computer system that usually commands by the coded program to the physical machine for performing some cutting or shaping processes.
CNC machines have wide applications in automatic process industries. These machines require high accuracy and need to perform repetitive actions flawlessly.
So Stepper Servo motors are the best choice to perform this kind of action.
Operation of Stepper Servo Motor:
Stepping servo is a high-speed, high-torque, high-precision, low-vibration, low-heat, and non-lost stepping servo solution based on an ordinary open-loop stepping motor, combined with position feedback and servo algorithms.
The Stepper Servo motor is formed by using a combination of
1. Open Loop Stepper Motor
The Stepper motor divides a full rotation into a number of equal steps. Thus, the motor’s position can be commanded to move and hold at one of these steps, as long as the motor is carefully sized to the application with respect to torque and speed.
The position control is achieved by a simple Open Loop control mechanism so doesn’t require complex electronic control circuitry.
Input pulse decides the rotation angle of the motor. The speed is proportional to the frequency of the input pulses.
2. Position Feedback Servo Motor Algorithm
The servo mechanism is used for precise control of the angular position. The servo mechanism is an error-sensing feedback control that is used to correct the performance of a system.
The Servo Motor utilizes a regular motor and couples it with a sensor for positional feedback. A type of encoder serves as a sensor providing speed and position feedback. This circuitry is built right inside the motor housing which usually is fitted with a gear system.
The servo motor can be moved to a desired angular position by sending PWM (pulse width modulated) signals on the control wire. The PWM signal determines the amount of movement which represents the final command position for the shaft.
Stepper Servo motor has enhanced characteristics than Stepper and Servo motors like High speed, High torque, and high precision. Low vibration, low heating, and no lost step.
Working of Stepper Servo Drive:
Stepper Servo Drive is used to control the Stepper servo motor.
It consists of the following controls
- The PID parameter adjustment function makes the motor better meet the application of different kinds of loads.
- The Field oriented control (FOC) is a Field-weakening control algorithm that makes the motor reduce the magnetic field characteristics and keep the power at high speed.
- The Current vector control function makes the motor have the current characteristic of a servo and low heating.
- Micro-stepping involves increasing the resolution of the motor by dividing the current between the two poles to provide half-steps when a motor offers fewer steps than you need. The Micro-stepping command algorithm makes the motor can run while maintaining a stable and low vibration at various speeds.
- The Encoder feedback of position and speed with pulse resolution up to 4000 makes the positioning precision increase and never loses the step.
