Thursday, April 18, 2024

A dexterous robotic hand can move the same as a human hand

A London-based robotic company, Shadow Robot crafted a robotic hand which is considered to be one of the best robotic hands ever created. It named as “Dexterous Hand”.

It takes over a decade for making, the robotic hand has 24 joints that are driven by 20 motors. With that wide range of freedom of movements, it can pick up even small and tricky objects like pencil, pen. Each joint has a movement range again the same as or very close to that of a human hand, including the thumb and even the flex of the palm for the little finger.

The robotic hand is also almost the size of a human hand. Within that small envelope, the team has packed highly sensed fingertips, absolute position sensors for each joint and control board on the palm allowing for system extension via add-ons. This increases operational capabilities significantly such as by wearing standard gloves for protection in specific tasks.

All thanks to the 129 sensors, the Shadow Dexterous Hand provides detailed telemetry which can be used for a detailed understanding of the environment.

As well as absolute position sensing for each joint the Hand includes force sensing for each actuator, tactile sensing on fingertips, temperature and motor current and voltage sensing. All of this data is made available to the user from 100Hz and up to 1kHz via a high bandwidth EtherCAT interface. Supporting this high frequency for data is the fast movement of the hand – from open to closed in 0.5 seconds.

Dexterous Hand
Dexterous Hand

Additionally, the hand is totally integrated with ROS. The company’s website suggests that you can download and start using a virtual model of the Hand in ROS right now. Control of the Hand, including position control algorithms, can be modified by the user in ROS. Firmware within the Hand itself can be made available for modification.

Also, in collaboration with SynTouch LLC, the team has made available the revolutionary BioTac tactile sensor in a package. These specially designed sensors can be added to all fingers and allow the detailed force, micro-vibration and temperature gradient sensing.

The robotic Hand can not only be programmed to perform tasks, but it also can be used to replicate human movements. The robot can tap out a message on a keyboard. When it types words on a keyboard, it’s actually copying, the movement for movement, a flesh-and-blood engineer kitted out with a HaptX motion-tracking glove. As the engineer types, each tiny press of the keyboard they make is detected through their glove’s tactile fingertip sensors and sent directly to the Dexterous Hand to recreate. All of this is achieved in real-time.

It is not about the writing only, the hand is able to follow its remote master in playing a game of Jenga, building a pyramid out of plastic cups, or moving chess pieces around on a chess board.

The robot has touch-sensing fingertips and transmits [that data] to haptic feedback devices on the glove so the human can feel [them],” Rich Walker, the managing director of the Shadow Robot Company, told Digital Trends. “The robot can also measure other forces — like the torque at the joints — and transmit those back for other haptic feedback devices. So we have a variety of senses of what is happening at the robot end that can be provided to the human end. In the other direction, as the human moves, we turn that into commands for the robot to make it move in a similar way.