Choosing the Right Robot

Robotics has been advancing at a rate of knots over the past 10 years and although the time of replacing the majority of manual labour with robot operations is still a long way off, there are some interesting new industrial robots appearing which come much closer to undertaking human tasks.  As an experienced robot integrator with years of experience and hundreds of installations, Cyan Tec Systems is well-placed to offer advice on the best and latest robot automation solutions.

Many suppliers are offering the new style of “collaborative robots”, one example of which is the YuMi robot from ABB, which has been launched recently.  This is perhaps the most mainstream of this genre, coming from one of the “big four” global robot suppliers which are expected to grow rapidly to take the place of more expensive robots or human operators.

What does the YuMi do?

The YuMi robot looks a lot more like, and shares many characteristics with, the human body.  Designed to work alongside humans, the most notable change from the typical industrial 6-axis robot is the fact that YuMi is designed to work in the open and not behind guarding and safety interlocks.

Image: YuMi robot (image courtesy of ABB Robotics)

YuMi is equipped with twin articulated arms which terminate in gripper hands.  The concept of collaborative robots is that a shop floor may consist of a mixture of humans and robots, the robots being able to feed or be fed by human operators who might be given the more complicated tasks (or tasks requiring human intelligence).  Movement speed is restricted and the arms are equipped with crash sensors to stop safely if they should come into contact with a human operator, avoiding the risk of pinch, crush or impact injuries.

Ideal for small electronic component assembly, the robot will not replace the traditional 6-axis industrial robot, rather it complements the range and expands the capabilities of robot-based automation.  The YuMi robot can use vision to correctly pick and place components regardless of orientation and with the ability to compensate for inaccuracy of position, in the same way a human would.  As well as having the dexterity of a human operator, the collaborative robot can be easily trained and re-trained, coping well with boring, repetitive or ergonomically challenging tasks.

Traditional robots

For some applications, where long reach or interpolated path following is required, there is no substitute for the speed and accuracy of the traditional 6-axis robot.  These robots are still the obvious choice where the robot is using a tool which necessitates full safety guarding (for example laser welding or cutting).  In these applications, the capability of the 6-axis robot makes it the most appropriate choice.

In other applications involving simpler action, it might be that a Scara robot with 4-axes is more suitable.  These robots have fewer movements than the full 6-axis robot and are often used for pick-and-place in assembly or in loading and unloading machines.


With robots, as with other elements in automation, there is no single solution which suits every situation.  Flexibility and open-mindedness will allow the optimum configuration to be found, taking into account all the criteria required by the application.  In the next decade it is likely that many more collaborative robots will be installed and new technology is enhancing the vision, motion accuracy and intelligence of robots.

When to use a SCARA Robot

What is a SCARA robot?

SCARA robots were first developed in the 1980’s in Japan and the name SCARA stands for Selective Compliance Assembly Robot Arm.  The main feature of the SCARA robot is that it has a jointed 2-link arm which in some ways imitates the human arm although it operates on a single plane, allowing the arm to extend and retract (fold) into confined areas which makes it suitable for reaching inside enclosures or pick-and-place from one location to another.  The SCARA robot is one of 3 major classes of robot which Cyan Tec Systems are experienced at integrating, namely:

  • Cartesian Robots (Gantry type)
  • Six-axis Robots
  • SCARA Robots

The selection of which type of robot to choose is not always clear-cut, but Cyan Tec Systems are in a totally unbiased position to recommend the best solution for the particular automation requirement.  This article considers the specific case of the SCARA robot and when it is most likely advantageous to use one.  In some cases the selection of the most suitable robot is straightforward and in others it is mainly down to a comparison on cost.   SCARA robots normally have up to 4 axes (3 rotation and one Z linear).

Selective Compliance Assembly Robot Arm – CYAN TEC


Advantages of SCARA robots

The SCARA robot is most commonly used for pick-and-place or assembly operations where high speed and high accuracy is required.  Generally a SCARA robot can operate at higher speed and with optional cleanroom specification.  In terms of repeatability, currently available SCARA robots can achieve tolerances lower than 10 microns, compared to 20 microns for a six-axis robot. By design, the SCARA robot suits applications with a smaller field of operation and where floor space is limited, the compact layout also making them more easily re-allocated in temporary or remote applications.


Limitations of SCARA robots

SCARA robots, due to their configuration are typically only capable of carrying a relatively light payload, typically up to 2 kg nominal (10 kg maximum).  The envelope of a SCARA robot is typically circular, which doesn’t suit all applications, and the robot has limited dexterity and flexibility compared to the full 3D capability of other types of robot.  For example, following a 3D contour is something that will be more likely fall within the capabilities of a six-axis robot.


Choosing the right solution

With many different factors influencing the choice of the robot for a specific application, it is wise to discuss with an automation expert.  Cyan Tec Systems have been integrating all types of robots for several decades and can advise on alternative concepts for system design and help to select the most suitable configuration.   Working with an experienced and independent supplier is the best way to define the automation configuration that suits the cycle time, accuracy and budget of the required production system.

Cyan Tec Systems has experience of integrating robots for assembly and loading/unloading of machinery.  Cyan Tec also offers systems for paint spraying, assembly, test and laser processing applications. Standard and bespoke systems are offered with a full service from design through manufacture, a large installed base worldwide is supported by a dedicated team of engineers.