General Electric Company

Carl G Ringwall

Allen W Case, Jr

Kenneth B Haefner

Michael L Pollick

Thomas Shaw Honda

An industrial robot is controlled to move by increments and approximately track an edge or a joint. A structured light pattern such as two parallel light bars is projected onto the workpiece and the scene is imaged by a visual sensor. Information derived from the image is used to compute move vectors. The navigation algorithm is based on extracting and computing the next move vector from the visual scene while the current move vector is being executed. The positioning system of an arc welding robot approximately follows the joint to be welded; the computed microvectors specify the direction and distance the positioning system moves.

Microvector control for edge and joint following

A high quality velocity signal is generated from an incremental position encoder, thus eliminating the DC tachometer in robot and machine tool closed loop control systems. The encoder signals are used to amplitude modulate the outputs of a high frequency oscillator. Two side band frequencies equal to the sum and difference of the encoder and oscillator frequencies are produced and converted to analog voltages and summed to yield a speed signal. This signal is continuous through zero rate and has a polarity determined by direction of rotation.

Velocity sensor and method of producing a velocity signal

A tactile area sensor for robots has an array of pneumatic flow passages. The air flow in each passage is dependent on a localized force exerted by an object pressing against an elastic pad on the face of the sensor. The air flow impinges on a metallic tab and its angular displacement is sensed by directing a light beam from an optical fiber onto the tab and monitoring the quantity of light reflected to a paired optical fiber. The array of optical outputs can be presented to a charge injection device and are dependent on the shape of the object.

Tactile sensor

A flowmeter of the fluid oscillator type having a fluid jet which oscillates at a frequency indicative of flow rate. By elimination of wall attachment effects and use of a proportional type amplifier, the range of the flowmeter is substantially extended beyond the limit of turbulent flow conditions. Linearity is improved by use of a differential pressure type of fluid jet control and the range may be further extended by use of multiple amplifier stages.

Fluidic flow and velocity sensor

A flowmeter of the fluid oscillator type having a fluid jet which oscillates at a frequency indicative of flow rate. A linear flow rate vs. frequency output characteristic is obtained by use of a fluid accelerating means in the form of a two-dimensional sharp edge orifice. The orifice has an aspect ratio selected to give a constant coefficient of discharge throughout an extended flow range including laminar and turbulent flow conditions.

Linear flowmeter

A fluidic accelerometer having a single sensitive axis. The accelerometer is comprised of a seismic mass having first and second end surfaces positioned perpendicular to the sensitive axis, viscous damping means for suspending the seismic mass in a normal null position and for damping oscillatory movement of the seismic mass in the direction of the sensitive axis, and means responsive to movement of the seismic mass in the direction of the sensitive axis for providing a restoring force to return the seismic mass to the normal null position and for producing an output fluidic signal variation proportional to the acceleration of the seismic mass in the direction of the sensitive axis.

Fluidic accelerometer

A torsional reed reference fluidic oscillator operating within 0.1% of the desired frequency over a temperature range of -65.degree. to +165.degree.F and an operating pressure of from 1 to 4 psi. The oscillator includes a torsional reed fluidic amplifier and fluidic feedback means for converting output signals from output ports of the amplifier to first and second input signals having a phase relationship for insuring operation of the apparatus as an oscillator. The amplifier is comprised of first, second and third plates, an elongated reed member, first and second torsional members and a tab, all of which are made of material having negligible thermal coefficient of expansion and negligible change in modulus of elasticity over the temperature range. The reed member is positioned within an elongated slot in the first plate, and is fixed thereto by the first and second torsional members, wherein the major axis of the torsional members is perpendicular to the plane and major axis of the reed member. The second and third plates each has a supply port, a channel fluidically coupled to the supply port, and an output port fluidically coupled to the channel. The tab, having a hole therethrough, extends from the reed member in a plane perpendicular to the major axis of the torsional members and the reed member. The tab is received within the channels in the second and third plates, and is movable between a first and second position upon corresponding movement of the reed member which is responding to the reception of the first and second fluidic input signals from the fluidic feedback means. The fluidic resonant frequency of the oscillator is approximately equal to a fixed mechanical resonant frequency of the reed member, whereby the oscillator oscillates at that mechanical resonant frequency.

Torsional reed reference fluidic oscillator

A closed loop fluidic angular rate gyro having a single sensitive axis. The gyro is comprised of a supporting member, fluidic means for sensing movement of the gyro about the sensitive axis, and means for pivotally mounting the sensing means to the supporting member and about a torsional axis which is perpendicular to the sensitive axis to maintain the sensing means in a normal null position and allow limited rotation of the sensing means about the torsional axis in response to the angular velocity of the gyro about the sensitive axis. The gyro is further comprised of fluidic or electrostatic means responsive to movement of the sensing means for providing a restoring torque to return the sensing means to the normal null position and for producing an output signal proportional to movement of the sensing means about the torsional axis, whereby the output signal is proportional to the angular velocity of the gyro about the sensitive axis. The gyro is fixed within an oil filled enclosure, and a flat damping plate is laterally positioned between the upper surface of the enclosure and the sensing means to stabilize the closed loop operation of the gyro.

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Scotia, NY, United States of America

Carl G Ringwall