The robot industry has for several decades focused on 1-armed robots, as the complexity and costs seldom has demanded more. However, the technological development has resulted in humanlike 2-armed robots which has several more functions and thereby is capable of meeting today´s broader range of industrial needs.
“Automating the human anatomy dictates that no changes should occur if a person is replaced by a robot or a robot is replaced by a person in the production.” Erik Nieves, technical manager at Motoman Inc. explains.
It is therefore interesting to follow the development in 2-armed robots. If a robot is to work in a cell originally designed for human labour, constrains and limitations may easily arise with a 1-armed robot.
Humans are in control
Nieves further explains that an industrial worker usually has one or two machines placed in front of him and maybe two on a conveyor belt behind him. This arrangement is made to spare the human from moving around from one machine to another. To automate the same layout it is necessary with a robot that is able to revolve around itself, while working with several stations. It is possible to locate working stations next to each other and put a traditional robot on a portal crane to move it from one station to another, however, this will not work if a human is to replace the robot.
“In connection with automation it is the humans who are in charge and not the robots” Erik Nieves states.
The market is currently introducing several interesting 2-armed robots. However, some are still in preparation. Nevertheless, the 2-armed robots support the philosophy that future robots need to be intuitive as seen with Robot CoWorkers. But one must admit that a 2-armed robot is easier to train, if you do not happen to be committed to hold one armed tied behind your back.
Following will be a closer look at the three most interesting 2-armed robots right now
Baxter from Rethink Robotics
The expectations were great when Rodley Brooks and Rething Robotics last year launched Baxter at the RoboBusiness Leadership summit event in the USA. The expectations had been formed by years of viral success leading to the event.
Therefore, the hype had grown so big that the expectations were almost impossible to satisfy. When Baxter entered the market it happened with an unprecedented low price of approximately $22,000. It was supposed to be a broad hint to other robot manufactures about which direction robots had to develop towards.
For robots the gears are especially important components which are hard to compromise on in the manufacturing. However, with Baxter, Rethink Robotics had managed to lower the costs in this area.
That decision ended up being at the expense of durability and accuracy. Baxter is good in several ways (!) like simple processes like handling tasks where objects need to be moved from A to B without demanding great accuracy e.g. putting objects in a box. Nevertheless, the question is if a 2-armed robot is really necessary to perform that task?
Dexter from Yaskawa Motoman
Yaskawa Motoman´s 2-armed robot consist of two seven axes arms out of totally 15 axes connected to a torso which is able to revolve around itself. The 2-armed robot is capable of handling 5 to 20 kilo per arm. Dexter is expensive, but do provide significantly higher speed and accuracy compared to e.g. Baxter.
“Yaskawa´s focus is geared in direction of montage and assembling where one specific widget need to fit into a specific hole etc. With this type of applications one can repeat the same process with accuracy down to one tenth of a millimetre.” Erik Nieves explains.
Frida from ABB
Like Dexter, ABB has a concept for 2-armed robots which takes it part of departure in the needs from the manufacturing and montage industry e.g. from assembling and montage of circuit boards and other electronic components.
The prototype has 14 different ‘degrees of freedom’. Moreover, it has an integrated camera system, flexible grippers and ABB´s IRC5 controller.
AAB has received positive feedback on Frida and will continue developing the concept before introducing it to the market.