Although the idea of gyroscopic stabilization is old, for example, the first use of gyroscopic stabilization for a ship was in 1917, the requisite lightweight components required to make a useful, gyroscopically stabilized walker have only recently been widely available. Gyroscopic devices tend to maintain their orientation, making them useful in many applications from the large scale (eg. ship anti-roll devices weighing many tons) to the small scale (eg. tiny gyroscopic sensors). Vertical stabilization requires resisting tilt in two directions: front to back and side to side. Walking aid devices need to be relatively light weight for an individual user to lift, turn, and move.
A prior attempt at producing a gyroscopically stabilized walking cane would produce only a small stabilizing force, and to our knowledge, is not commercially available. Other devices, including wearable backpack-like gyroscopically stabilized devices, seem unfeasible due to potential weight and size, difficulty putting on and off, and furthermore, would likely produce very little stabilizing force. There are numerous fall-detection sensory devices with small gyroscopes, but these devices do not make use of direct gyroscopic torque for stabilization.
After seeking input from consultants including a physicist, physical therapist, medical device safety specialist, physicians, and most importantly, patients with imbalance, our device design has evolved. After countless additional hours of work and contemplation, we have iterated multiple prototypes. We now have a walking aid prototype device that uses direct gyroscopic stabilization to resist tilt and falls in more than one direction. Both of a user’s hands are utilized, rather than a cane or wearable device. The user stands at the ideal location for stability.
The device activates in response to tilt. Initially, reaction wheel effect force is utilized to help slow the fall. We know of no prior attempts at making a walker stabilized by reaction wheel effect or gyroscopic effect. Check out videos on youtube of other devices including a cube device (no affiliation with USAGYROMOBILITY, INC.) stabilized by reaction wheel effect.
As the flywheels quickly spin up to speed (in less than 1/2 second), reaction wheel effect force lessens, and gyroscopic stabilizing force takes over. The cool thing about reaction wheel effect is that it is maximal at flywheel startup, and then reaction wheel effect wanes as the flywheels build up speed (angular momentum). This compliments, very well, with gyroscopic stabilization, which begins at zero and then builds as flywheel speed increases. Reaction wheel effect forces (a.k.a. motor torque) can be vectored (aimed) in the ideal direction to counteract the direction of fall. This is because each motor may start in either spin direction, and they don't necessarily have to start at the exact same time. Furthermore, direction of subsequent flywheel gyroscopic precession doesn't matter (it can go at least 45 degrees in either direction). Using a small servo motor or linear actuator along the rail system, flywheel location and rate of precession can be directly controlled. Therefore, gyroscopic force can be 'metered out' as the device tilts and falls, so that it does not suddenly 'give way'.
Why not just add more flywheels? Flywheel moment of inertia, and therefore gyroscopic torque, are proportional to the square of the flywheel radius. From a weight perspective, it is better to have fewer, larger flywheels rather than more numerous smaller flywheels. Size and geometry dictate maximal diameter and practicality of the flywheel arrangement. By building and testing different orientations, we have come to the conclusion that a vertical flywheel orientation is clearly optimal. The minimum, and therefore optimal, number of flywheels required is 2. We have several key design trade secrets for functionality.
Future design improvements for the counter-balancing walker include: adding wheels using super-capacitors for saving weight, using a capacitance switch at the handles (so that it only works if the handles are held); potentially adding straps or other safety features; and potentially adding a seat.
We fully understand that no single device can prevent all injuries from falls, however, we are excited about the potential of this unique device!
