Distributed Control-A Key Enabler for Smart Industry

The basic concepts behind Smart Industry is making manufacturing more efficient, more intelligent and aware, and more connected.  In order to enable these concepts, there are a wealth of development efforts ongoing in different areas of the industry. One of the most demanding applications in this context is motion control for industrial robots where finding new ways to integrate the electronics to contribute to this function is something can bring great benefits.

From centralized to distributed control solutions

Traditionally the electronics for motion control in industrial robots has been housed in racks and cabinets near the robot. This means that there are many cables and connectors linking the control functions to the motors, switches, and actuators that they drive. It also means having specialists in the factory able to install, operate, and maintain this complex collection of elements.

Imagine now integrating all those control electronics directly in the robot near the parts they are driving – so they are already installed when the robot is delivered to the factory. This would bring many benefits:

* Material and space savings – cabinets, racks, cables etc.

* Installation and operation labor-cost savings

* Higher Efficiency – lower energy losses than with cables

And, with the right electronic components integrated, we could have higher flexibility to adapt the machine to the needs of the manufacturing task.

This is, of course, easier said than done. To tackle this task ST has for several years been partnering with Robox spa, a company that designs and manufactures electronic controllers, programming languages, and development environments for robotics and motion-control systems.

A highly integrated smart, safe motion-control module

One product of this cooperation exemplifies the benefits of this approach – the SPIMD20 motion drive module, which is designed to be integrated directly into brushless motors.

The SPIMD20 is an innovative mechatronic motion-control solution that combines an array of integrated circuits (chips), mechanical parts, and dedicated software. The module is designed for applications which need to control multiple motion axes and are also looking to reduce the cabling system and rack dimension.  Typical use cases include packaging machines, process machines, and industrial robots. The module is highly configurable so it can be adapted to different types of motors and working profiles.

SPIMD20 includes a full-bridge IGBT inverter, a control unit that uses two STM32 microcontrollers and a communication interface and is ready to be integrated with any brushless three-phase motor up to 2kW. The module works up to 800 VDC and performs all motor-drive functions including adjusting speed, position (interfacing both resolver and EnDAT 2.2 position sensors), and current loop execution, plus it performs connectivity tasks. Connection to the master is performed via Industrial Ethernet (Ethercat®) and CANOpen®. The SPIMD20 also offers the flexibility to easily implement different Industrial Ethernet protocols, as required.

Retrofitting motors with an all-in-one module is a matter of mechanical constraints: the SPIMD20 has overall dimensions of 165 x 60 x 26 mm and weighs less than 0.5 kg. This compactness allows the integration in motors of different sizes.

The SPIMD20 is also a key enabler for a safe Smart Industry. It embeds the STO (Safe Torque Off) functionality, and its architecture meets all the most common industrial safety standards.