Change concept
What if the advantages of closed-loop servo technology can be applied to stepper motors? Can we achieve the same performance as servo motors while achieving the cost advantages of stepper motors?
By combining closed-loop control technology, the stepper motor will become a low-cost, comprehensive product with the advantages of both servo and stepper motors. Because closed-loop stepper motors can significantly improve performance and energy efficiency, they can replace more expensive servo motors in more and more high-standard applications.
Servotronix embeds closed-loop control in its stepIM integrated stepper motor.
The stepper motor with integrated electronic control is equivalent to a two-phase brushless DC motor that performs position loop control, speed loop control, DQ control, and other algorithms. Closed-loop commutation with a single-turn absolute encoder ensures optimum torque at any speed.
In this regard, we can consider stepIM products.
Low energy consumption and cooling
StepIM stepper motors are energy efficient. Unlike open-loop stepper motors that operate consistently with full current commands, which can cause heat and noise problems, the stepIM current will vary depending on the actual motion, such as during acceleration and deceleration. Similar to servos, the current drawn by these stepper motors is proportional to the actual torque required at any time. Because the motor and integrated electronic control board operate cooler, the stepIM stepper motor can achieve higher peak torques similar to servo motors.
Exact match performance requirements
To ensure that there is sufficient torque to overcome interference and avoid out-of-synchronization, open-loop stepper motors typically have a torque that is at least 40% higher than the value required for the application. This problem does not exist with closed-loop stepIM stepper motors. When these stepping motors reach the stall state due to overload, they will continue to maintain the load state without losing torque. They will continue to run after the overload condition is removed. The maximum torque is guaranteed at any given speed, while the position sensor ensures that no step is lost. Therefore, the size of the closed-loop stepper motor can be precisely matched to the torque requirements of the relevant application without the need for an additional 40% margin.
For open-loop stepper motors, it is difficult to meet higher transient torque demands because of the risk of out-of-step. The stepIM closed-loop stepper motor achieves fast acceleration, lower operating noise, and lower resonance than conventional stepper motors. They operate at higher bandwidths and deliver outstanding performance.
Cabinetless machine
stepIM integrates the drive control board with the motor, reducing the number of connections and simplifying the implementation. With stepIM, you can build a cabinetless machine.
Below we examine the motion control performance in a wood cutting application, which is typically performed using a servo motor, but now it is implemented with a stepIM closed loop stepper motor. (The following is a wood cutting application case we have studied. To achieve the motion control performance required by this application, it is usually implemented by servo motor. Now we use StepIM closed-loop stepper motor to achieve.)
