Robotics Researchers Aim Beyond Their Grasp, Literally, with Dual Independent Mobile Manipulators
What if you could detach your arms and send them off on independent errands? That's effectively the goal of this new research project.
Researchers from Osaka University and University College London have designed a robotic system which aims to extend the capabilities of the human body, giving the user remote operation of two mobile manipulators — extending the ability to reach and handle items well beyond the length of the user's arms.
"The proposed idea of incorporating two independently movable manipulators for motion-tracking-based teleoperation is intriguing. However, there [were] some inherent issues to be addressed," explains corresponding author Weiwei Wan. "First of all, how to map the postures of the human teleoperator's two arms to the corresponding manipulator’s poses. In addition, how to avoid it when under some circumstances, the manipulator may collide with itself. Moreover, how to remotely monitor the two manipulators with the large operating range."
Key to the team's work is that the mobile manipulators in question aren't two arms attached to a single mobile base, as with the human body, but two independent arms attached to two separate bases — allowing them to wander off in different directions, something a human would find distinctly uncomfortable unaided.
The work was directly inspired in mobile robotics efforts that surrounded the Fukushima nuclear power plant disaster in 2013, in which remotely-controlled robots were used to enter areas too dangerous for a human. "The research interest in remote control has been further signified in the past 2 years as the coronavirus disease 2019 (COVID-19) pandemic restricted people's movement," Wan adds. "A series of robots were developed and remotely deployed at the Wuhan hospitals to assist doctors and patients."
In the team's take on the task, each mobile base corresponds to one of the user's hands. A motion capture system based on gloves with integrated inertial measurement units (IMUs) tracks the user's hand movements and mimics them with the robot arm, while joysticks — repurposed Nintendo Wii nunchucks — are used to move the mobile bases on which they're mounted. To prove the concept, the prototype system was used for multiple tasks — including picking up and delivering a coffee mug using only one manipulator and base, and using two in tandem to pick up and place long sticks too unwieldy for a single manipulator.
"Since there are two mobile manipulators, the presented system could keep the advantages of having two arms while extending the human body functions," says Wan, "The results demonstrated the effectiveness of the proposed system, resulting in extending the human body to a large space while keeping the benefits of having two limbs."
The team's work has been published under open-access terms in the journal Cyborg and Bionic Systems.