Son Creates Bionic Leg Chair for Father

Maker Jake Laser has developed an adaptive personal mobility system. He built this "bionic leg chair" for his father, who has lived with multiple sclerosis for two decades. The system aims to remove barriers posed by rough terrain, steep inclines, and stairs. It permits navigation beyond the capabilities of conventional wheelchairs.

Credit: Jake Laser /YouTube

The project began with an industrial grade quadruped robot manufactured by Unitree. This platform features a hybrid leg and wheel design. Powered wheels are mounted beneath each foot. This configuration allows the machine to roll efficiently across smooth surfaces. It also retains the ability to step over obstacles, climb stairs, and navigate uneven ground as necessary. The Unitree robot provided a suitable foundation for an all terrain mobility device.

But adapting the robot for safe human transport involved more than attaching a seat. Laser conducted experiments with various layouts. He determined that mounting a racing bucket seat directly onto the robot's spine was the only arrangement. This allowed the mechanical legs to move without interference. Positioning the rider's legs straight forward also eliminated contact with the walking mechanism. A stable seating position was simultaneously provided. The seat was subsequently customised with a heavy duty safety harness and decorative trim. This trim matched his father's preferences.

The robot was engineered to carry substantial loads. However, these loads were not intended to shift constantly, unlike a human passenger. Laser modified the robot's software to accommodate this requirement. He recalibrated its stabilisation system. Onboard gyros and motors now compensate for the additional weight. This ensures the device maintains balance during operation.

And the completed system operates via a wireless dual joystick transmitter. This control interface allows the rider to direct the robot's movement. Functions include driving forward, strafing sideways, and rotating. The rider can also command the robot to raise or lower itself. This feature facilitates easier entry and exit from the device.

So, with the core system functional, Laser then focused on aesthetic enhancements. Carbon fibre accents were incorporated. Curved body panels, drawing inspiration from classic 1940s Bugatti automobiles, were added. Vintage style chrome headlights, underbody LED lighting, and custom spinner wheel covers further transformed the industrial robot. These additions made it resemble a futuristic concept vehicle.

Before entrusting the machine to his father, Laser subjected it to a series of rigorous tests. The robot demonstrated its capability by climbing tall ledges. It walked across the open rungs of a ladder. It navigated full staircases. The device also crossed a rocky riverbed without any loss of footing. Only following these trials did his father then board the apparatus.

His father subsequently reported accessing locations he had been unable to reach for over two decades. This included various outdoor environments previously impassable by conventional mobility aids. According to Hackster.io, this project represents a one off build. It is not currently a commercial product available for general purchase.

But this initiative demonstrates the potential of creative engineering. It suggests how significant financial investment, amounting to a six figure sum in USD for the base robot, can produce advanced assistive technologies. Such bespoke projects highlight possibilities for future personal mobility solutions.

• A personal mobility device was engineered from an industrial quadruped robot.

• The system enables access to diverse terrains, including stairs and rocky riverbeds.

• Extensive modifications involved custom seating, software recalibration, and aesthetic enhancements.

• This bespoke project, developed for a family member, is not a commercial product.

Source: Hackster.io