ESR Pollmeier GmbH - Servo Drive Technology

Drive Tasks

Servo drives by ESR are used in various applications and carry out manifold tasks such as

For choosing the right servo drive system, you also have to consider whether the servo drive should carry out PLC functions and how to transmit the setpoints or integrate the drive into an automation system.

This page provides an overview of common cases of application for servo drive systems. In addition, uncommon drive tasks are realized in special applications with ESR servo drive systems, too. If your application is not listed here, we therefore ask you to get in contact with us. We will be glad to advise you without any obligation.

Positioning (Point-to-Point)

The classical field of servo drive usage – to accelerate to the rated speed within a few milliseconds only to decelerate a short time later just as quick. And of course the target position is to be reached exactly with an error of a few hundredths of a millimeter.

With Digital Servo Drives and AC Servo Motors, Torque Motors, or Linear Motors:

In profile position mode it is sufficient to transmit the desired target position to the digital ESR servo drive (e. g. by using Ethernet or a fieldbus interface) to let the drive move to that positon – in a way defined before with parameters like target velocity and acceleration and deceleration ramps. Using motion profiles, the positioning can be optimzed, e. g. for movements with particular low jerk. Additionally the integrated part program offers a complete positioning control in the device (servo drive integrated PLC, see below).

Typically, AC servo motors are used, if required with gear boxes and/or holding brakes. Depending on the application, the motor is set up as rotatory drive system (e. g. rotary table) or mounted to a linear module as a toothed-belt, ball-screw, or rack and pinion drive. In applications with higher demands on precision and dynamics, the digital servo drives may also be combined with direct drives such as torque motors or linear motors.

More information: ▪ Digital Servo DrivesAC Servo MotorsTorque MotorsLinear Motors

With Analog Servo Drives and AC or DC Servo Motors:

The analog servo drives do not offer an operating mode for positioning. Here, the higher-level controller takes care of the position control and transmits speed setpoints via the ±10 V interface to the servo drive. After the target position has been reached, the optional holding control loop can ensure that the position is kept. For linear movements, linear modules are used as toothed-belt, ball-screw, or rack and pinion drives.

More information: ▪ Analog Servo DrivesServo Motors

Rotatory Movements, Velocity Profiles

With their particularly good control behavior and the smooth motor run, complemented by the acceleration and deceleration ramps which can be defined exactly, both analog and digital servo drives by ESR are suitable for use as speed controlled drive, e. g. in test applications or processing machines.

With Digital Servo Drives and AC Servo Motors or Torque Motors:

The desired speed is set in velocity mode via a communication interface or the ±10 V interface. User-defined acceleration and deceleration ramps are taken into account. The control loops ensure that the speed is maintained even under changing load, e. g. during treatment of a work piece.

By using the part program the digital servo drives can perform complete speed profiles on their own. These profiles are used e. g. in optical disc manufacturing, when the liquid coating is applied and then centrifuged. Special part program blocks for speed profiles make the definition of different ramp profiles and slopes easy. The part program can contain several such speed profiles and let the user choose e. g. via the digital inputs or an Ethernet or fieldbus interface which profile to apply.

More information: ▪ Digital Servo DrivesAC Servo MotorsTorque motors

With Analog Servo Drives and AC or DC Servo Motors:

The desired speed is set via the ±10 V interface. With their analog control loops, the analog servo drives by ESR reach a particularly high control quality. Smooth running at its best is achieved with DC servo drive systems, e. g. for measuring applications.

More information: ▪ Analog Servo DrivesServo Motors

Tool Change, Component Change, Spindle Positioning

In some applications, the rotatory movement has to be interrupted from time to time, and the axis should then move to a certain position, e. g. to change the work piece or tool.

With Digital Servo Drives and AC Servo Motors or Torque Motors:

ESR's digital servo drives are prepared even for this task. After all necessary parameters have been set once, a signal at one of the digital inputs or via the Ethernet or fieldbus interface is enough to initiate the spindle positioning and to restart the rotatory movement afterwards.

More information: ▪ Digital Servo DrivesAC Servo MotorsTorque motors

With Analog Servo Drives and AC or DC Servo Motors:

When using analog servo drives systems, this function is typically realized in the higher-level controller. For simple applications, the optional holding control loop function can be used as an alternative.

More information: ▪ Analog Servo DrivesServo Motors

Axis Synchronization (Electronic Gearing, Electronic Cam Disk, and Flying Shear)

In many machines the motion of one axis depends on the motion of another axis. Mechanical solutions are intricate in realization and servicing and lead to wear and tear. In new applications or when it comes to refurbishment of an old machine, the "upright shaft" principle is therefore usually replaced by an electronic solution.

The solutions described here are just a few among many possible approaches for coordinated movement of multiple axes, especially when a central master axis can be omitted and the synchronization can be left completely to the higher-level controller (see below).

With Digital Servo Drives and AC Servo Motors, Torque Motors, or Linear Motors:

The "electronic gearing" function of ESR's digital servo drives allows coupling of a master and a slave axis at an adjustable gear ratio.

If the gear ratio between master and slave axis is not constant, the "electronic cam disk" function can be used. A software tool helps to adapt the "shape" of the electronic cam disk to the application (e. g. for packaging machinery or die cutters).

Another case of application is a continuous material flow that must not be interrupted while cutting, printing, testing, or otherwise processing the material. A special, repetitive motion sequence is used in this case: While processing the material the slave axis has to synchronize with the material flow, after that it has to run back to the starting position. This function, called "flying shear" or "flying saw", is already integrated in the digital servo drives by ESR (partly as an option) and requires only a small effort during parameterization (for cutting length, return velocity etc.).

The scope of function is rounded off with switching points that can be set to arbitrary positions in order to switch on or off up to eight digital outputs automatically depending on the actual position of the axis.

More information: ▪ Digital Servo DrivesAC Servo MotorsTorque motorsLinear motors

With Analog Servo Drives and AC or DC Servo Motors:

When using analog servo drives systems, the coordinated movement of the slave axes is typically induced by the higher-level controller. The optional synchronization unit can be used for increment-precise synchronization of two axes.

More information: ▪ Analog Servo DrivesServo Motors

Multi-Axis Applications, Coordinated Movement, and Motion Control

For the flexible coordinated movement of multiple axes, e. g. in handling and assembly systems or pick+place applications, high-performance multi-axis controllers are used. They calculate permanently new setpoints for the individual axes based on the actual values and the desired trajectory. Typical applications are roboter functions, synchronous or path-optimized movements of multiple axes.

With Digital Servo Drives and AC Servo Motors, Torque Motors, or Linear Motors:

A fast, real-time capable communication channel (e. g. EtherCAT or CANopen) is used for transmitting the setpoints continuously to all axes. Using the "Interpolated Position Mode" and three other cyclic-synchronous operating modes, ESR's digital servo drives can process these setpoints, interpolate them finely, if required, and convert them into movements.

More information: ▪ Digital Servo DrivesAC Servo MotorsTorque motorsLinear motors

With Analog Servo Drives and AC or DC Servo Motors:

With their ±10 V interface, the analog servo drives by ESR can also be used in multi-axis applications with coordinated movements.

More information: ▪ Analog Servo DrivesServo Motors

With the Multi-Axis Servo System and Any Type of Servo Motors:

The multi-axis servo system, consisting of motion control modules and servo power modules, is specially designed for the coordinated movement of multiple axes. The remarkable thing about it is that very different kinds and types of motors can be driven flexibly in parallel.

More information: ▪ Multi-Axis Servo SystemServo MotorsTorque motorsLinear motors

Coiling, Moulding, Extruding: Torque Mode and Force Mode

Compared to other controlled drives, ESR servo drive systems have the advantage of a very accurate and dynamic current control. They produce full torque even at standstill or low velocity (stall torque). The precise current control allows a sensitive torque control, as used e. g. in coil winding machines. The high stall torque is useful e. g. in presses.

With Digital Servo Drives and AC Servo Motors, Torque Motors, or Linear Motors:

In "torque mode" or "force mode" the current setpoint can be set directly via an Ethernet, fieldbus, or the ±10 V interface. Monitoring functions protect servo drive and motor and avoid overload of the drive system.

More information: ▪ Digital Servo DrivesAC Servo MotorsTorque motorsLinear motors

With Analog Servo Drives and AC or DC Servo Motors:

The torque setpoint is transmitted via the ±10 V interface. Here too, monitoring functions avoid overload of the drive system and protect servo drive and motor.

More information: ▪ Analog Servo DrivesServo Motors

Further Operating Modes and Technology Functions

In our development department we continuously improve our devices – new functions are added, existing functions are extended and refined. It is frequently our customers who challenge us, and we will put all our effort into satisfying you as our customer.

More information: ▪ Solutions

PLC Functions

With the integrated positioning control of the digital servo drives by ESR, complete sequence controls can be realized within the device. All technology functions of the servo drive and all interfaces are also accessible to the part program.

An operator terminal can be used to display actual values and to influence the program behavior, whereas in simple applications, push-buttons, switches, and control lights may be sufficient. In applications with just one axis or with only few axes that are independent from each other, a higher-level controller may even be expendable.

More information: ▪ Digital Servo DrivesPositioning controls

Communication with Higher-Level Controllers

Another important question when choosing the appropriate servo drive system: How to integrate the drive into the automation system. All servo drives by ESR are equipped with a ±10 V interface for easy setpoint transmission of current or speed. The digital inputs and outputs as well as the USB or serial interface of the digital servo drive provide for further communication possibilities. Optionally, these devices are available with Ethernet or fieldbus interface (e. g. EtherCAT, CANopen, Profinet, Modbus/TCP, or Profibus DP).

More information: ▪ Servo drivesIndustrial Ethernet and fieldbus interfaces