Component, Software Improvements Enhance Robot Capabilities

Advances in components and software are enabling today’s robots to implement a wider of material and product handling tasks in biomedical, industrial, and other applications. Improvements in motors, actuators, industrial controllers, and control algorithms are allowing robots to operate with greater flexibility, while ensuring a higher degree of operator safety. Robots have long been used in relatively repetitive applications involving picking and placing of objects or spray painting and finishing. Now, they are finding their way into uses where parts are small, delicate, or require a more flexible range of motion. Products such as food, pharmaceuticals, photovoltaic panels, and wind turbines are now being handled by robots. noted Ted Wodoslawsky, vice president of marketing for ABB Robotics (Auburn Hills, MI).

Robots, such as this one from ABB Robotics, are increasingly used for delicate material handling, such as photovoltaic panels.

“Robots are very much a compilation of existing technologies,” said Peter Cavallo, Director of Sales for Denso Robots (Long Beach, CA). “They have become faster, more accurate, and more versatile.”

Component and subsystem advances are a key reason. Motors and linear actuators are getting lighter in weight and lower in cost. “Lighter motors are enabling the robots to carry higher payloads,” Cavello noted. Steve Feketa, Global Product Manager of Linear Motion and Automation for Rockwell Automation (Troy, MI), added, “Magnetic linear encoders that used to cost $500 are now $100 to $200.”

Dave Becksoffer, Applications Engineering Project Manager for motor supplier Portescap (West Chester, PA), added, “The torque/force production capabilities of step motors and step motor-driven actuators have increased over the last few years. Higher energy magnets, together with flux focusing magnets, enable higher performance in a smaller package size, allowing smaller yet more powerful robotic designs. “Higher levels of customization, including finer lead screw pitch sizes on actuators as well as hollow shaft designs in hybrid motors, give the engineer greater design flexibility. Robot movement speed can be increased, due to the higher performance of the motors and actuators, improving application throughput and speeding response time.”

Piezoelectric motors are starting to emerge in robotics applications, noted Scott Jordan, Director of Nanopositioning Technologies for Physik Instrumente (Auburn, MA). “Their benefits in terms of speed, responsiveness, stability, and size are remarkable, and they are enabling applications from fast valve actuators to liquid dispensing systems, microscopy, and semiconductor manufacturing.”

MEMS (Micro Electro Mechanical Systems) technology is giving designers a convenient, cost-effective means to shrink component size while increasing reliability, functionality, and computing power, according to Kirk Barker, Electronics Product Manager for Maxon Motors (Fall River, MA). The company incorporates MEMS technology in its recently released MILE encoder, which produces a high level of positional accuracy due to inductive coil technology. It is immune to EMI, magnetic fields, dust, and oil.

Control Systems
Robot control systems are also advancing. Robot makers are gravitating toward integrating robot control functions into programmable line controllers, rather than using dedicated robot controllers. “We integrate the robot directly into the line controller,” said Robert Hirschinger, Product Marketing Manager of Motion Products for Rockwell Automation. “We can now program the robot we control directly in Cartesian coordinates and avoid data handshaking issues.”

Maxon recently unveiled its second-generation network position controller, the EPOS2. The controller features a 32-bit digital signal processor and is based on the CANopen standard. It is available with numerous IEC 61131-3 libraries and is ideal for decentralized control in a number of network applications.

ABB Robotics, Auburn Hills, MI, has unveiled SafeMove, a software and electronics based safety controller integrated in the IRC5 robot controller. SafeMove offers a host of leading-edge safety functions and reduces the need for traditional safety equipment such as light curtains, safety relays, mechanical stops, mechanical position switches, and protective barriers, allowing organizations to save money on installation and maintenance.

“Because you’re using software and electronic position sensors, you can make robotic cells smaller and reduces the footprint,” said Ted Wodoslawsky, vice president of marketing. “One of our partners built a virtual fence with the help of SafeMove, making it possible to build a smaller palletizing cell.”SafeMove also enables more compact cells by restricting robot motion to precisely what is needed for a specific application, instead of relying on more inflexible mechanical stops.”

Vision capabilities are also being incorporated directly into the controller, rather than a separate vision system. noted Mike Cicco, Director of Material Handling for Fanuc Robotics America (Rochester Hills, MI). This configuration eliminates the need to separately program vision cameras.

Robotic software continues improving as advanced algorithms are developed to handle more complex robotic motion sequences, according to Brian Powell, Software Principal Architect for National Instruments (Austin, TX). “We have a lot of different sensors and actuators we need to communicate with. We need to come out with better abstractions of the different inputs and outputs and free users from having to perform low-level programming.”

National is leveraging its LabVIEW platform for its new NI SoftMotion Module, which simplifies development of advanced single- and multi-axis robotics and other motion control applications. NI SoftMotion integrates with the company’s CompactRIO programmable automation controller. The module has advanced functions to generate trajectories, interpolate splines, and perform position and velocity control and encoder implementation.

Robot makers are integrating hardware and software to ease and speed up robot implementation. Rockwell Automation has introduced the MP Series integrated multi-axis stages, which gives users an out-of-the-box solution for users looking for precise two-positioning and velocity control. The stage can carry payloads of up to 25 kilograms with an acceleration of 1 gram at maximum payload. Motion Analyzer software from Rockwell lets the user enter information about the load and how it needs to be moved. The software lets users select the approximate stage and drive for the application.

Better software algorithms are also improving robot safety. “Software can now implement a ‘dual-check’ safety feature that creates a 3-D zone the robot can safely move in,” said Cicco. “Traditionally, with a robot the only way to safely guard unwanted motion was to incorporate a dynamic limiting switch device. This tended to limit the robot’s joint movements.”

The bottom line, said Denso’s Cavello, is that “Safety systems will catch up with how people work. Robots will take over more dangerous jobs and allow more complex processes and products to be performed with greater consistency and accuracy.”

As software advances, future robotic cells are likely to deploy multiple robots working alongside one another, added Powell. Citing examples such as swarms of search-and-rescue robots, Powell said that multiple robots offer the advantage of redundancy, should one robot break down in the field.