Circumferential Scissor Spring Enhances Precision in Hand Controllers

About this technology

Overview

Innovators at NASA Johnson Space Center have designed a circumferential scissor spring mechanism, that when incorporated into a hand controller, improves the restorative force to a control stick’s neutral position. The design also provides for operation on a more linear portion of the spring's force deflection curve, yielding better feedback to the user. Physical hand controllers, such as translational and rotational controllers, use a non-circumferential scissor spring arrangement to return the control stick to a neutral position, but the linear response of a typical scissor spring arrangement can reduce a user’s sense of control by allowing slack between deflections. This innovation’s design is driven by a spring mechanism whereby an expansion spring is looped around the channeled circumference of two rounded pivoting blades whose setup can be tuned to allow varying spring tension. This allows the user enhanced control stick sensitivity while operating drive systems, industrial automation, measuring technology, mobile machinery, and gaming systems. This technology is currently implemented on NASA’s Orion Spacecraft training simulators using three-axis hand controllers.