Velocity transducer

Abstract

A velocity sensor which may be modified to perform a sensing function for either angular velocity or linear velocity. The sensor has a base member which is split into upper and lower halves which are shaped to form internal walls defining an internal channel when joined together. A fluid is disposed in the internal channel and a paddle member is placed in communication with the fluid. Sensing means are present to detect the position of the paddle member as it is urged into motion by the inertia of the fluid mass in the angular embodiment and by the inertia of the paddle member in the linear. An electrical output is provided which is related to the urge to move imparted to the paddle member. The output is used to electrically restrain the motion of the paddle member. The output related to paddle member motion is also integrated to provide a signal related to velocity. Saturation of the integrated output unrelated to velocity is prevented by additional electrical means. AC input, DC internal operation, and AC output is provided as well as fast automatic nulling after application of power, self test means and an inhibited output in the event of electrical failure within the unit. The fluid mass flow path being integral with the base member substantially eliminates thermal gradients within the fluid mass, removing error arising from fluid flow due to thermal gradients. Linear acceleration sensitivity in the angular velocity sensor embodiment is eliminated by paddle member balance about the pivot axis within the fluid mass during assembly. Pivot stabilization during shock and vibration loads is provided by adjustable leaf spring supports disposed between the paddle and the base member. The AC output phase shift relative to the AC input is substantially eliminated over the operational temperature range as compared with conventional instruments of this type.