In the beginning
I have been developing motor drives since 2006 and the first development project was a cost efficient implementation of AC/Brushless servo drive that would suit in CNC machine applications (another hobby of mine). The outcome was so promising that we (I and my colleague, Timo Piiroinen) decided to start a company to manufacture and sell them. To see details about the first drive, follow this link to my old hobby web site. The first drive was called VSD-A (Versatile Servo Drive) and it was sold at 2007. The most significant contributios of VSD-A:
- 1 kW sinusoidal AC servo motor drive with excellent cost efficiency
- Encoder feedback with pulse-and directio reference input
- Wide supply voltage range of 12 to 200 VDC
New ideas didn’t stop coming into my mind, so soon after VSD-A I started planning the next drive. The direction of development was to add more sophisticated features, power, ruggedness in a smaller package. One of the design innovations were the card form factor that is easily installed inside a cabinet with holes for D-sub connectors that reach out of the box without any intermediate wiring. The another very significant innovation was a DualDC operating mode where single drive could control two independent servo motor axis. The outcome is called VSD-E where E stands for Evolution. VSD-E is still in production and will continue to be produced as long as it has enough demand. The significant contributions of VSD-E:
- Elegant design allows installing inside cabinet like PC expansion cards
- Supports most of AC/BLDC and DC servo motors while keeping affordable price
- Voltage range of 12-160 VDC and power up to 2 kW
- Single drive can also drive two independent DC servo axis
- Protected against various fault cases (short circuit etc)
Listening the Customers
After selling numerous amounts of VSD-E, we have got lots of feedback and discussion about topics like setup and desired features of a “dream drive”. In no time a new drive started forming in my mind. Some most important things that we felt we need to change about VSD-E:
- Form factor – no matter how much we love the VSD-E’s form factor, in many cases it was easier to install traditional enclosed/boxed drive inside cabinet than a card type drive. This time drive should be wall mountable box instead of a PCB card.
- Connectors – the new design should have pluggable screw terminals to easily connect large motor leads
- Supply voltage – to eliminate the need of external AC to DC power supply unit, the drive should directly accept AC mains voltage as supply. This adds some cost but it will in total save money as external PSU isn’t free either.
- Connectivity – in some cases users find the I/O’s of VSD-E limiting (such as no 24V signals can be fed to it without external resistor). This time we extend I/O voltage range to include the standard 24V while same time increasing number of I/O’s. Now there is enough I/O for dedicated axis limit switches.
- Monitor & setup – the new drive should be able to communicate simultaneously to configuration & monitor software tool while drive is being used by the actual application (such as CNC controller).
- Field bus – the drive should have a field bus connectivity for those who don’t prefer to use old school reference signals (step/dir, analog, etc).
- Sensitivity – the drive should be hardened against virtually any amount EMI interference. The new design should have more configurable fault tolerance levels to adapt better in difficult environments (such as arc welding machine).
- Flexibility – VSD-E (as any other drive on market today) has fixed functionality. Users are able to configure it to behave different ways, but not able to do much outside the predefined set of functions. The new drive overcomes this limitation by incorporating “user CPU” that can run user code. User CPU allows implementing stand-alone controls as well as additional I/O and feedback support.
- Safety – one of the most missing feature in the motor drive products in general. The new drive should have built-in functionality for safety stopping with various ensured motor stopping mechanisms.
- Setup – the setup & diagnosis software should be 100% rewritten from ground up. Amount of confusing parameters need to be minimized while preserving functionality.
It does it all, then it does more…
The upcoming drive has been named as Argon. The original plan was to call it VSD-R after Revolution. However the name didn’t sound revolutionary enough to justify the significance of the design changes. Argon practically means the rebirth of the whole business for us, and hopefully even more for the customers.
Argon servo drive hardware design has been finished on August 2013 and devices are now in full production. Argon is being used in multitude of applications, including robotics, CNC machine tools as well as professional grade force feedback systems (i.e. racing simulators).
More about Argon:
- Argon Product page
- Wiki page (product details)
- Full specifications (electrical specifications)
- User guide
- Support (ask a question about Argon)
Argon is available world wide through Granite Devices web shop as well as many of Argon distributors.