Motion Control: Unitronics PLCs and Servos Precisely Position Punch Press

A motion control system for a fast and accurate variable hole-punch machine was designed by a system integrator using the UniStream® 7”All-in-One PLC + HMI  paired with two AC Servo Drives from Unitronics. Plus, the machine can be controlled remotely via any mobile device.

A motion control application story from Unitronics

hold punch machineA system integrator in India, Shriram Automation, needed to build a motion control system for a demanding application that required a robust PLC, two Servo drives, and a color-touch HMI screen.   The ability to access the machine and application remotely via mobile was an additional necessity. They selected UniStream® 7”All-in-One PLC + HMI paired with two AC Servo drives from Unitronics.

The project was for a machine which contains three separately controlled hydraulic presses. Each press punches holes that are spaced and sized according to a specific profile. When the operator feeds a channel into the machine, each press automatically punches holes according to the selected profile. The servo drives handle the channel positioning which should be near-flawless. The holes must be positioned within a tolerance of 0.5mm otherwise it will not pass the quality check.

The objective was to increase production by enabling the machine to punch all three types of holes on a channel during a single feed.  The goal was achieved.  As a result, the machine can completely process an 8 meters long channel in only 40 seconds.

By the precise positioning and motion control capabilities of the UniStream PLC together with Unitronics servos efficiency was attained. The controller automatically calculates the positioning for the servo pusher and puller as per the hole distances. When the pusher servo reaches its end limit, the puller servo acts by pulling out the remaining part of the channel out from the punch die, while the controller performs calculations to plot the remaining holes.

Time-Saving Advantages

UniLogic™ All-in-One software enabled the engineer to setup, configure, and tune the servo drives and motors in the same environment that he used to build both his control and HMI programs.  Plus, not only can the user enter servo parameters via the UniStream’s built-in HMI panel, but it can also be accessed via VNC on a mobile phone.