Life goes on - more than you think: "Autonomyo" exoskeleton
Walking without crutches - that is a dream of longing for people with certain neuromuscular diseases. With the exoskeleton "Autonomyo", which was developed by the Research Group for Rehabilitation and Assistive Robotics (REHA Assist), it should now be able to come true. The active walking aid supports the weakened muscles and allows an intuitive movement sequence that follows the natural one. The additional power comes from six small motors. To facilitate harmonious interaction between the exoskeleton and its user, drive system manufacturer FAULHABER has developed an all-in-one component motor with torque sensor.
Partial support in lightweight design
Weighing just 25 kilograms, the assistive device is said to be significantly lighter than others of its kind. It also works by incorporating the patient's weakened but still partially functioning musculoskeletal system.
The device is attached to the torso with a corset and to the user's legs with cuffs. On each side, three motors provide the power that the muscles lack for movement. One each is responsible for flexion and extension of the hip and knee, with another motor for the knee.
The third motor supports abduction and adduction of the leg in the hip joint, i.e. the lateral movement of the leg away from the body's central axis. All in all, the motors help the patient both maintain balance and walk upright.
In a recent clinical trial that included people with walking disabilities, Autonomyo reportedly worked as intended: The exoskeleton provided support while allowing freedom of movement according to the user's intentions. Joint range of motion and gait cadence were not negatively affected.
Drive performance and development potential
The total of six drive units per device originate from the drive system manufacturer. At their core is the 3274 BP4 brushless motor with a diameter of 32 millimeters. In its size class, it is said to offer the highest power available on the market.
Its power is transmitted by a 42 GPT planetary gearhead with a shaft made specifically for this application. An IE3 magnetic encoder provides position data to the controller. The torque sensor is integrated into the gears of the four motors for the flexion and extension movements.
Although the component is not part of the series products for the time being, development engineer Frank Schwenker can already envision several other areas of application: "The high-resolution torque measurement can bring great added value in all haptic applications. This applies, for example, to all kinds of robotic assistance in the operating room, where the surgeon guides the instrument, and the machine provides force and precision. But the sensor can also perform a protective function and be used for torque limitation. It's also perfect for documentation in quality assurance, wherever very accurate torque values need to be verified."
