A hovering remote-control flying craft having a molded frame assembly includes a plurality of arms extending from a center body with an electric motor and corresponding propeller on each arm. In various embodiments, the motor and propeller are mounted downward-facing at a distal portion of each arm with a motor cover over the motor. The center body can be formed of a two-piece molded structure that sandwiches a circuit board to provide structural support for the frame. The circuit board can include a plurality of tabs that facilitate mounting of wire connectors, and can also provide antennas and emitters for both IR and RF communications. In some embodiments, a removable safety ring protects the propellers from lateral contact.

Remote-control flying copter and method

A homeostatic flying hovercraft preferably utilizes at least two pairs of counter-rotating ducted fans to generate lift like a hovercraft and utilizes a homeostatic hover control system to create a flying craft that is easily controlled. The homeostatic hover control system provides true homeostasis of the craft with a true fly-by-wire flight control and control-by-wire system control.

Homeostatic flying hovercraft

A position tracker uses an inertial angular measurement system, for measuring orientation and linear translation of a helmet on a human head for the synthesis by a host computer of virtual, directional audio over headphones sensors mounted on the helmut, includes a roll gyro sensor, a pitch gyro sensor, a yaw gyro sensor, an absolute roll tilt sensor coupled to a first universal signal conditioner, an absolute pitch tilt sensor coupled to a second universal signal conditioner, and an absolute yaw compensator. A data acquisition system is coupled between the sensors and the host computer for converting analog signals from the sensors into digital, angular orientation data. Each of the gyro sensors includes angular velocity detectors and solid state electronic devices connected to provide angular velocity signals at a given sample rate.

Virtual navigator, and inertial angular measurement system

A magnetically damped inclinometer has a shaft with attached pendulum that rotates. The rotation causes an index member to rotate past one or a set of magnets or electromagnets that are connected to the load. The magnet or electromagnet may be mounted directly the load or it may be in the form of an off center ring. Another embodiment uses a spring to bias two magnets apart. A cam is attached to the shaft such that, as the pendulum and shaft rotate, a roller connected with the load or spreader bar allows the spring to push the magnets farther apart. The damped inclinometers are used to determine and provide information to respond to the initial sway of a load prior to bringing the load to a stop.

Apparatus and method for measuring and controlling pendulum motion

Systems are able to reduce or remove slowly-varying drift errors, such as heading errors, rate of rotation errors, and direction of travel errors, to correct the measurements from tracking devices The systems may be used to remove the slow varying drift errors for gyroscopic tracking device sensors, or other types of sensors used for determining heading, rates of rotation, direction of travel, or position The systems may be employed in personal dead reckoning systems, or other personnel tracking device, as well as in vehicle tracking devices The system uses heuristic assumptions to correct for these drift errors, via a feedback loop control having an accumulator responsive to changes in output signals The accumulator is able to produce a signal that over time compensates for the inherent drift errors on those output signals

Heading Error Removal System for Tracking Devices

A feedback circuit for generating an output signal from a sensor that makes changing electrical and temperature characteristics of the sensor and any sensing medium irrelevant. The sensor is placed in the forward loop of the circuit to make the output depend on the area of the parallel plates the sensor, not on any electrical or temperature characteristics of the sensor or sensing medium. A liquid filled sensor having parallel conducting plates, one solid and the other being split into two differential plate sections may be used in the forward loop as a liquid level sensor or an inclinometer. Alternative sensors such as inductive sensors may also be used.

Liquid level and angle detector

The present invention provides a vertical reference that includes sensors providing signals indicative of angular tilt from the predetermined reference axis and the rate of angular tilt; an integrator to integrate the angular rate signal to provide a dynamic angular tilt signal; a pendulum to provide a signal indicative of angular displacement relative to the predetermined axis; a first amplifier for filtering and amplifying the dynamic angular tilt signal and the angular displacement signal to produce a first amplified signal; a second amplifier for filtering and amplifying the dynamic angular tilt signal and the angular displacement signal to produce a second amplified signal; and a dual input amplifier for combining and amplifying the first and second amplified signals to produce an output signal indicative of vertical reference and attitude. In another embodiment of the present invention a vertical reference apparatus includes a cascaded second-order filter or control loop having a first second-order loop that receives its inputs from the pendulum and the angular rate sensor and a second second-order loop that receives as its inputs the output signal of the first loop and the angular rate sensor. The output of the second loop is provided to a control system for the structure whose orientation is desired to be measured or stabilized. In this alternative embodiment of the present invention each control loop includes a summing amplifier, a summing damped integrator, an inverting amplifier, and an integrator.

Vertical reference and attitude system

PROBLEM TO BE SOLVED: To provide a sensor circuit generating an output signal proportional to the liquid level in a tank or the angular displacement of a sensor independently from the temperature or electrical characteristics of a sensor of a medium to be detected. SOLUTION: A feedback circuit generating an output signal from a sensor produces an output regardless of the temperature or electrical characteristics of a sensor or a medium to be detected. A sensor 14 is set in the feedforward loop of a circuit 10 and produces an output dependent on a region of parallel plates but not dependent on the temperature or electrical characteristics of sensor or a medium to be detected. The sensor 14 comprising parallel conductive plates and filled with a liquid has one complete plate 28 and the other divided differential plates 24, 26 and used as a liquid level sensor or a clinometer in the feedforward loop. Other sensor, e.g. an inductive sensor, may also be used.

Drew A. Karnick

Papers

Liquid level and angle detector

Vertical reference and attitude system

Output-signal generating circuit