Making industrial robots move more smoothly could reduce their energy requirements by up to 40 per cent, a study found.
According to researchers from Chalmers University of Technology in Sweden, robots that do not speed up and slow down too much would be more energy efficient while producing as much in as little time as their less optimised counterparts.
“We simply let the robot move slower instead of waiting for other robots and machines to catch up before carrying out the next sequence,” explained Professor Bengt Lennartson who initiated the research together with car maker General Motors.
“The optimisation also determines the order in which the various operations are carried out to minimise energy consumption – without reducing the total execution time.”
The researchers used a special algorithm to calculate the optimum speed of movements.
All the changes only affect the speed and sequence of movements but never the robot’s operational path.
“Thus, we can go into an existing robot cell and perform a quick optimisation without impacting production or the current cycle” Bengt Lennartson said.
The key to the best performance, the researcher said, is in coordination and optimisation of several robots operating in the same area. The optimisation tool will initially identify where robots may collide, and the entry and exit positions for each collision zone, and for each robot path.
“The first test results have shown a significant improvement, such as a 15 to 40 per cent energy reduction, but the results are still preliminary,” said says Kristofer Bengtsson, a member of the team. “In order to estimate the actual energy savings, further testing in industry is required.”
In robot-intensive manufacturing industries, such as bodywork factories in the automotive industry, robots consume about half of the total energy used for production.
The optimisation program starts by logging the movements of each robot during an operations cycle, as well as any collision zones. This information is processed by the optimiser, which generates new control instructions that can be directly executed by the robots.
“The goal is to make this kind of optimisation standard, and included in robots from the start,” Bengtsson said. “At each adjustment of the operating sequences, a new optimisation is conducted by default. But as we all know, it takes time to bring a development product into a robust production process, with several years of engineering work.”