AsianScientist (Sep. 12, 2017) – Scientists in China have developed an algorithm that can help robots to move and balance themselves. They published their findings in the journal IEEE/CAA Journal of Automatica Sinica.
Pop culture promises a wide array of robots to aid humans, from the Jetsons’ housekeeper, Rosie, to the adorable and helpful R2D2 and BB8 in the Star Wars universe. They may not yet be capable of washing dishes or smuggling holograms, but the robots of our time are getting better at moving.
In this study, a team led by Professor Chen Mou at the Nanjing University of Aeronautics and Astronautics has proposed a method to better control the tracking of self-balancing mobile robots. According the Chen, the sliding mode control technique is the most commonly used way to regulate the behavior of the robot. This technique pulls information from the non-linear system, which can behave differently depending on varying factors, including time. The algorithm organizes the information into a representation of the robot’s normal behavior.
“Although different [sliding mode control] schemes have been extensively studied in the practical systems, the [sliding mode control] needs to be further improved for self-balancing robots,” said Chen.
Chen also noted that the dynamic information of a variable called the ‘unknown disturbance’ should be fully utilized. To better understand the unknown disturbance, which could be skidding or slipping, scientists introduced a disturbance observer into the sliding mode control technique. This technique mathematically determines the value of an unknown disturbance, allowing the sliding mode control method to adjust and keep the robot behaving normally.
Chen’s proposed method is a refined version of the previously developed disturbance observer controller.
“By using the output of the nonlinear disturbance observer, the tracking control scheme has been designed using the sliding mode technique. This guarantees that all the closed-loop signals are ultimately uniformly bounded,” said Chen.
The robot, no matter the disturbance, should still end up moving in the desired trajectory.
Chen tested his algorithm with the parameters of a self-balancing mobile robot produced by Googol Technology Consulting Inc., a China-based company specializing in the research and development of controller-based systems.
“The simulation results show good tracking performance,” said Chen. “In our future work, experimental studies will be conducted for the self-balancing mobile robot.”
The article can be found at: Chen (2017) Robust Tracking Control for Self-balancing Mobile Robots Using Disturbance Observer.
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Source: Chinese Association of Automation; Photo: Pixabay.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
