After years of interest in articulated arm robots, there’s resurgence in the Cartesian robot structure because of payload capability, cost effectiveness and ease of programming, asserts Karl Rapp. “As automation increases, users are finding that a Cartesian robot is a better fit,” says Rapp, automation and machine-tool branch manager for Bosch Rexroth’s Electric Drives and Controls, in Hoffman Estates, Ill. The resurgence of these robots is occurring in all manufacturing sectors, he observes, including automotive-parts handling and package/case palletizing. Cartesian robots are even supplanting rudimentary machining processes, he adds.
These robots, known also as Cartesian coordinate or rectangular coordinate robots, move vertically or horizontally. Typically, the robot consists of a horizontal arm attached to a vertical axis, all of which is mounted on a base. That gives the x, y and z axes. Such robots have been around for quite a while, Rapp notes. But what’s new about these robots’ current revival, he believes, is the focus on multiple processes, multiple ancillary axes, high-performance networking to surrounding processes and integration of vision.
One trend in integration of robotics and vision systems involves medical surgery. “This will continue to grow to give way to total surgical procedures performed by robots,” Bashar predicts. This trend takes advantage of the success in linking robots and vision systems, as well as other peripherals—all controlled by one controller, he notes.Another recent development Rapp mentions is the expansion in manufacturing of the concept of safe motion. “This allows the operators of robotics to set up the operation and tweak the process while inside the work envelope, without endangering themselves,” he explains. Bashar adds that he believes operator safety, as well as manufacturing efficiency, directly link to current robotic advancements and new robotic developments.
What’s new on the horizon for industrial robotics? Rapp believes it’s the combination motor/drive designed for higher continuous torque. “We have seen special-purpose drive/motors before, but the latest technology allows for these integrated units to handle higher payloads, while greatly reducing the cabinet size, cabling and troubleshooting time compared to conventional, discrete devices,” he explains.
Brain surgery?
For Bashar, it remains surgical robotics, which he labels “an evolving technology” that will remain so until enough confidence is built to allow robots to perform solo surgeries. “Currently, the robotic arm is moved and operated by the surgeon. I expect that these many kinds of procedures will become fully robotic in the next five to 10 years.” Driving the evolution of this application are end-user demands for ease-of-use and ease-of-programming, commissioning and set-up of Cartesian robots, he adds. These demands also apply to the growth of these robots in manufacturing, specifically automotive, medical, electronics, assembly automation and packaging.
The development of simplified controls platforms for Cartesian robotics brings these robots to the folds of standard robotic
platforms, Bashar states. That means further inroads into manufacturing. “This latest development [in the use in surgical robots] frees up the integration and the commissioning of the Cartesian
robotic platform from the need to learn, understand and acquire servo programming and commissioning knowledge, which is highly technical and limited to engineers and highly experienced electrical technicians,” he explains.
