Swedish researchers say they can reduce the energy consumption of industrial robots by up to 40% by using an algorithm to optimize the movement of robotic arms. The algorithm reduces the "acceleration and deceleration" operations of the robotic arm and shortens the time it spends in a stationary state, as energy is constantly consumed even when the robot is stationary.
Optimization does not change the robot's operating path, only its speed and operation sequence. Optimizing robots can save a considerable amount of potential costs, because in robot-intensive manufacturing applications, such as bodywork in the automotive industry, robots can replace about half of the productivity.
“We’re simply slowing the robot down a bit, rather than waiting for other robots and machines to catch up before executing the next sequence,” explained Professor Bengt Lennartson of Chalmers University of Technology, who initiated the research in collaboration with GE.
“Optimization also determines the order in which various operations are performed to minimize energy consumption—but without reducing the total execution time,” he added. “Therefore, we can go into existing robot modules and perform rapid optimizations without impacting production or the current cycle.”
To ensure safety, the movements of different robots operating in the same area need to be coordinated. Therefore, the optimization tool initially identified areas where robots might collide, as well as the locations of each collision zone and the entrances and exits of each robot path.
Tests conducted at the Robotics and Automation Laboratory at Chalmers University of Technology showed that a single robot can save 15-35% of energy, while a multi-robot system can save up to 40%.
The research team from Chalmers University of Technology (from left): Dr. Christopher Bengtsson,
Professors Emma Widalson and Bent Lennarson.
“The initial test results showed significant improvements—such as energy savings of 15-40%—but the results are still preliminary,” said Dr. Christopher Bengtsson, a Chalmers researcher who helped implement the new optimization strategy. “Further testing is necessary to estimate the actual energy savings.”
The optimization program first records the movement of each robot and all collision zones within a running cycle. This information is then processed by an algorithm to generate new control commands for the robot.
“Our goal is to standardize this optimization, embedding this optimization technique into the robot from the very beginning,” Bentsen said. “Every time the sequence of operations is adjusted, a new optimization will be performed by default. But we all know that it takes several years of engineering work to mass-produce a product that is still in development.”
The robot optimization work currently underway at Chalmers University of Technology is part of the Areus EU project, which is developing hardware technologies to optimize bidirectional energy flow and improve the use of renewable energy in factories. The project is also developing a new power supply system that will reduce the energy consumption of robotic automation systems. The Areus consortium has ten members across six EU countries, including Daimler, KUKA Robotics, and Danfoss.
