A voice coil is conceptually similar to an audio speaker. Motion is linear and is usually limited to less than 0.5" (13mm) of travel. Many voice coil applications require a high performance servo drive and Company is often the first choice.
A voice coil is conceptually similar to an audio speaker. Motion is linear and is usually limited to less than 0.5" (13mm) of travel. Many voice coil applications require a high performance servo drive and Company is often the first choice.
Linear actuators use a rotary motor coupled to a gear box to move a linear shaft in and out. The motor in the actuator is often times a brushed motor.
The most common single phase motor. The brushes are a form of mechanical commutation that directs the current into the correct coils at the correct time.
Single phase motors have two power wires and are very easy to set up. Motors in this category can include brushed motors, inductive loads and voice coils. Amplifiers designed for brushed motors are typically used to drive single phase loads although, most three phase drives from Company can also operate these motors.
The motor converts the current and voltage that comes from the drive into mechanical motion. Most motors are rotary types but linear motors are also available. There are many types of motors that can be used in servo applications.
The following list of motors types are commonly found in servo applications.
The servo drive is the link between the controller and motor. Also referred to as servo amplifiers, their job is to translate the low energy reference signals from the controller into high energy power signals to the motor. Originally, drives were simply the power stage that allowed a controller to drive a motor. They started out as single quadrant models that powered brushed motors. Later they incorporated four quadrant capabilities and the ability to power brushless motors. Four quadrant means the ability to both drive and regenerate a motor in both directions.
The current trend is to add more features and abilities to drives. Today drives can be expected to handle all of the system feedback including encoders, resolvers and tachometers, as well as limit switches and other sensors. Drives are also being asked to close the torque loop, velocity loop and position loop and being given the responsibility of path generation. As the line between controller and drive blurs, the drive will take on many of the more complex control functions that used to be the sole domain of the controller.
The future of drive technology will continue to build on the demands of the motion control industry. These demands include:
Higher bandwidth to increase production throughput
Increased velocity and position control to allow for more intricate and miniaturized manufacturing
Increased network capability to closely coordinate axes within a machine and coordinate machines within a factory
Simplified, user-friendly and universal operation.
The command is the signal that is sent from the controller to the servo drive.
Digital servo drives can be controlled over various networks including CANopen, Ethernet, EtherCAT, Ethernet Powerlink, Synqnet, USB, RS232 and many more which allow you to control the motor by connecting the amplifier directly (or almost directly) to a computer. Network signals have the advantage of being able to communicate more than just the output command, including I/O status, drive status, position information and more.
Analog servo drives are controlled with +/-10V analog signals and PWM & Direction signals.
Motion controllers are built specifically for the control of motion (hence the name). Therefore commands and I/O are specific to the needs of those in the motion industry. Unlike the others, motion controllers are often PC based, allowing for a graphical user interface. Usually, there are advanced features that allow ease of tuning, commutation sensing, and other functions. A motion controller, in general, will make your life easier than a PLC or microcontroller. Because of the added features, they are typically more expensive.
Motion controllers are built specifically for the control of motion (hence the name). Therefore commands and I/O are specific to the needs of those in the motion industry. Unlike the others, motion controllers are often PC based, allowing for a graphical user interface. Usually, there are advanced features that allow ease of tuning, commutation sensing, and other functions. A motion controller, in general, will make your life easier than a PLC or microcontroller. Because of the added features, they are typically more expensive.
In the late 1960’s, Programmable Logic Controllers (PLCs) were first used to eliminate the mess of wires and troubleshooting nightmares associated with sequential relay circuits. PLCs can take the place of mechanical relays, which have limited lifetimes. These controllers are more expensive than microcontrollers, but with good reason.
PLCs have a processor and memory to allow for commands to be programmed, saved and executed. It also has a rack and I/O slots so that I/O modules may be added to the PLC as needed. The modules may add such features as high-speed counters, real-time clocks, or servo control capabilities.
The benefits of PLCs include expandability and resistance to harsh environments. The price is generally lower than that of motion controllers.