Alla inlägg av Björn Stegfeldt

New function added – Force Control

Some customers have asked for Force control possibility on the flexible positioning unit, so we decided to implement it. No need for cumbersome calculations, everything is handled by our software. Simply enter the requested force in Newtons (N). The internal controller calculate and control the pressure to bore size ratio, and ensure any deviations are corrected thanks to the feedback loop from the embedded pressure sensors. The high frequency of the valves will correct for leakages, load variations etc. quicker that you will notice. 

Have a look at the short example on our Youtube channel:

https://youtu.be/qUsnNXXqNAo

Application example, paralell drive of pneumatic actuators

In this application example, we demonstrate how we can adjust the position of one pneumatic actuator with our flexible positioning unit, FPU, and use the feedback signal to control the other actuator, effectively making it a slave of the other. This type of setup can be useful when it is important that parallel actuators move simultaneously. Which delay do you get? typically 10 mS.

A water level is used to demonstrate the alignment precision. We made this example for a customer that want to use one actuator as master and three actuators as slaves.

Watch the video on our Youtube-Channel:

https://youtu.be/-QjPvqvFGO4

New functions added on the Flexible Positioning Unit, FPU

When we discuss with the users of our positioning unit, we sometimes come across new ways of using it, and some of our customers also come with ideas of new functions. The functions that we see a general benefit from get added to the firmware. Most of the new functions can be turned on and off, so the users can choose which functions they want.

In the latest update, we have added the following functions:

Soft-Start

When re-starting an exhausted system, the unit monitor the pressures, and slowly build up pressure to avoid rapid movement that isn’t wanted. Standard on all units from April. Software update available for older units.

Enable function with pre-determined default function

Some customer have asked for an ”Enable signal” possibility, with pre-determined default function when the enable signal dissappear. This function has been added, and can be turned ON or OFF as not all customers want it.

The ”Enable function” has 4 modes that can be chosen for when the ENABLE signal dissappear:

1: Valves passive – all valves closed (trapped air), no movement even if a position signal is sent.

2: Exhausted Position – No air to the actuator even if a position signal is sent.

3: Retracted Position – Actuator return to home position

4: Extended Position – Actuator engage full stroke and stay in end position

Example video : https://youtu.be/jruuFDhkDkk

The enable function is currently only available for users using 4-20 mA position control as we use the voltage port for Enable signal. Next generation of the unit (released in August) will have separate enable port, so it will be available for all users. The enable function possibility is added from April, Software update available for older units.

Pneumatic Gripper, finger positioning

We have several customers that want to control pneumatic gripper fingers.

Often they want to control the finger positioning to reduce cycle time. There are also many cases where they use the grippers for other applications than gripping, for example Centering, pushing etc. To demonstrate our technology and the capabilities with our flexible positioning unit, FPU, we have uploaded a video on our Youtube channel. In this video, you can see how we position the fingers into different positions on an SMC MHL2 pneumatic gripper with D-MP position sensor. You can also see live feedback on a graph, where we present the control signal and the actual position. You can control any standard pneumatic actuator with our unit, simply add a standard analog signal (4-20mA, 1-5V, or 0-10V) for required position. There is also a feedback signal of the same type.

The video can be seen at: https://youtu.be/LcmorPuFzAo

How does this work?

Our positioning unit use 4 extremely fast 2/2 valves, 2 for each actuator chamber, one for exhaust and one for supply. It also monitors the pressure in each chamber with pressure sensors, actual position with the help of a position sensor. The internal regulator that calculates how to control the valves uses a closed loop PID-Controller.

How is this unique?

We turn analogue Pneumatics into digital Pneumatics.

Positioning of pneumatics have, traditionally been inaccurate and slow. Our valve technology combined with advanced control achieve accuracy and speeds earlier not seen in pneumatics.

Contact us for your control needs of pneumatic actuators. We can work with standard rod based actuators, double rod type, rodless, grippers, and also rotary tables and air motors. We can also supply you with complete systems with actuators and sensors etc. We have a lot of application experiences, so feel free to ask for advise.

We look forward to connecting with you!

Application example, Emergency stop

We regularly get specific application questions, and we will post the most common ones.

On emergency stop or during service, it is common to exhaust the air. This is extra important on pneumatic actuators as they stand for a lot of the mechanical movements. The application will determine what you want your actuator to do. In some case, you want the actuator to stay in position (which is our standard setup), and in some cases you want the actuator to loose all power so it can be moved by hand. Below is an application example, where our positioning unit is used for a positioning application with a pneumatic actuator. AND-valves are connected to the exhaust, which will release all air inside the actuator. Our positioning unit will sense that the air is gone and reduce valve cycling to 20Hz, and continue with positioning as soon as the air is returned. As the unit is using a closed loop controller, you will always know the position from the monitor signal, even if the actuator is moved by hand. video on https://www.youtube.com/watch?v=nS1YkTarxjI


Application example, high accuraccy positioning

Visit our Youtube channel to  view our latest application example.

High accuraccy positioning of an SMC MXQ pneumatic precision Actuator with D-MP position Switch.

Our closed loop flexible positioning unit turn standard pneumatic actuators into complete positioning systems.

Very simple control – just use a standard analogue signal (i.e. 4-20 mA) for required position – no programming required.

Many customers prefer our solution in comparison with electric actuators and AC-Servos due to the simplicity, the cost benefit and the plug-and play functionality.

https://youtu.be/cEA4ohgANVk