Servo systems experience resonance due to compliance or backlash in mechanical components such as gearboxes, screw drives, and couplings. Resonance reduces system performance, can cause audible noise, and in extreme cases can even damage hardware. Servo tuning is the process of setting controller gains to optimize servo performance, but as gains are increased, resonances typically […]
Servo Drives
How do brushless-motor drives eliminate motor power-supply setup?
In a recent video recorded at the Design World studios, I teamed up with my colleague Paul Heney to review the features of a brushless-motor drive from Koford Engineering in Winchester, Ohio. Consider some examples from Koford Engineering, which sells a full line of compact 5, 10, 15, 20, 30, and 40-A brushless motor drives. […]
What are auto-tuning methods for servo drives?
Tuning a servo system is a complex and iterative process. It typically requires tuning multiple control loops, each with its own gains (proportional, integral, and/or derivative) to be adjusted. In addition, tuning a servo drive usually requires adjustments to additional parameters including acceleration and velocity feed-forward gains and filters to reduce oscillations. While manual tuning […]
Catching up with Oriental Motor at MD&M East
Earlier this month, I spoke with Viet Le, Senior Sales Engineer, Oriental Motor at the MD&M East/ATX East show in New York City. The company was showing off its AZ series of closed-loop absolute mechanical encoder stepper motors—they feature low vibration and high efficiency, and you don’t even have to purchase a battery back-up or […]
Where are digital servo drives used?
The original servo drives are analog types that operate on ±10-Volt inputs. In contrast, digital servo drives operate over fieldbus networks that now dominate the market. The primary difference in construction between digital and analog drives is that a digital drive includes a microprocessor to carry out computations — in turn to determine the output […]
Where are analog servo drives used?
The purpose of a servo drive is to convert low-power signals from the controller to high-power signals to the motor, instructing it to produce the desired torque or velocity. Servo drives (also referred to as servo amplifiers) can operate on either analog or digital input signals. Analog servo drives receive ±10-Volt analog signals from the […]
Applied Motion Products expands SV200 servo drive offering into DC-powered applications
Applied Motion Products, Inc. has now expanded the SV200 Servo Drive offering with the release of new drives designed for use in DC-powered applications. Existing SV200 servo drives are designed for 120 or 220 VAC operation, while the new DC-powered drives are designed to operate on 24, 48 or higher DC voltages — up to 60 […]
How are servo system velocity control loops tuned?
Servo systems typically use a combination of three types of control loops: current, velocity, and position. The velocity control loop serves two purposes—it enables the system to respond to changing velocity commands, and it allows the system to resist high-frequency load disturbances. But the velocity loop by itself can’t ensure that the system maintains a […]
Why is the bandwidth of a servo control loop important?
A servo drive can include any combination of three types of control loops—a position loop, a velocity loop, and a current loop. While each loop’s purpose is to control a different aspect of the motor’s performance, they are all characterized by a common parameter: bandwidth. The bandwidth, or response time, of the system is a measure […]
STSPIN250 STMicroelectronics launches tiny 2.6-A brushed dc motor driver for portable, battery-powered IoT devices
The STSPIN250 single-chip 2.6A driver for brushed DC motors extends STMicroelectronics’ family of miniature, low-voltage, energy-efficient drivers for battery-powered portable and wearable applications. The driver integrates a full power-MOSFET bridge and fixed off-time PWM current controller in a tiny 3mm x 3mm package that saves space in portable equipment. The low on-resistance of the power stage (200mΩ […]
