Sentec Corporation

Trw Limited

Philip A Gaubis

Takeo Sawatari

Thomas Joseph Wand

Philip Q Guest, Jr

Clark J Charnetski

Yuping Lin

Alex Klooster

James M Marks

James L Graves

Brenton L Mattes

Michael E Behr

Kenneth P Wozniak

A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.

Fiber optic temperature sensor

A fiber optic pressure catheter includes a light source, an optical fiber coupled to receive light from the light source and a sensor head that is optically coupled to the optical fiber. The sensor head has a housing defining a chamber coupled to an end of the optical fiber opposite the light source. The housing has an opening which is enclosed by a membrane. The membrane is responsive to pressure differentials between the chamber and outside the sensor head. A resilient ribbon is coupled within the chamber and has a first end fixedly coupled to a support. The ribbon has a second end that is movable in front of the optical fiber. The ribbon is mounted so that the middle portion of the ribbon touches the membrane and is biased by the membrane in response to various pressure differentials. Thus, various amounts of light are reflected back into the optical fiber based on the amount of pressure at the membrane. A detection system is optically coupled to the optical fiber which determines the pressure at the sensor head from the contrast of spectral fringes of light created by an optical coating on the end of the optical fiber and the light reflecting from the ribbon.

Fiber optic pressure catheter

A visibility sensor system includes a housing having a sensor head opening. A removable sensor head assembly is removably coupled to the housing within the sensor head opening. The sensor head assembly has a sensor enclosure and a connector. An electronics module is coupled to the sensor head through the connector.

Visibility sensor system

A scatterometer for detecting and analyzing wafer surface defects includes a light source generating a beam of light and a photodetector. Optics are used for splitting the beam of light into a reference beam and a detection beam. Optics also direct the reference beam and the detection beam to the photodetector through different optical paths. The optics direct the detection beam to the surface of the wafer and when incident upon a defect creates a scattered beam. The optics direct the scattered beam to the photodetector. A driver moves the surface of the wafer with respect to the detection beam. A computer coupled to the photodetector determines the presence of a defect on the surface by analyzing an interference pattern from the superposition of the reference beam and the scattered beam.

Heterodyne scatterometer for detecting and analyzing wafer surface

An electronic control system for a steering assembly having an electric motor coupled to the steering assembly for providing power assist. The electric power assist motor is drivably connected to a steering member for assisting movement thereof in response to applied input torque to the vehicle steering wheel. The electronic control unit monitors an output signal from a torsion sensor which measures the amount of applied input torque. The electronic control unit generates a pulse width modulated signal having a duty cycle proportional to the measured amount of applied input torque. Solid state switches provide connection between the vehicle battery and the motor, the connection time being controlled by the duty cycle of the pulse width modulated signal. A speed decoder determines which of a plurality of speed ranges the vehicle is moving. A plurality of look-up tables are provided, each table includes a value of power assist for a given amount of applied input torque. A look-up table is selected depending upon the decoded vehicle speed. Soft start circuitry is provided to control the maximum amount of assist that is permitted upon initial application of power to the electronic control unit. The amount to assist permitted increases from a minimum to a maximum within a predetermined amount of time. Temperature foldback circuitry is also provided to limit the amount of current through the electric power assist motor dependent upon sensed temperature of the solid state switches. The amount of current permitted through the motor is also limited to an absolute maximum. A connection cable is provided to reduce radiated electromagnetic emissions and voltage transients.

Electric steering gear

An electronic control system for a steering system having an electric motor coupled to the steering system for providing power assist. The steering system is of the rack and pinion type having an input gear coupled to the steering wheel and a pinion gear in meshing engagement with the rack. Two torsion sensors are coupled across the input and pinion gears and generate analog output signals. When no input torque is applied to the steering wheel, the output signals from the two torsion sensors are equal. When input torque is applied to the steering wheel, the signals from the torsion sensors vary substantially linearly in opposite directions. An electronic control unit controls operation of the electric power assist motor in accordance with the output signal from one of the torsion sensors. Failsafe circuitry is provided for monitoring the outputs of the redundant torsion sensors to insure proper control of the electric power assist motor. The failsafe circuitry provides (i) a sensor-to-sensor check to insure the output voltage of one sensor is consistent with the output voltage of the other sensor, (ii) a sensor limit check to insure that the output voltage from each sensor does not exceed a predetermined limit, (iii) a sensor direction check to insure that the signal being used to drive the electric power assist motor, as derived from one sensor, will drive the motor in the same direction sensed by the other sensor, and (iv) an excess assist check to insure that the signal used to drive the electric assist motor, as derived from one sensor, will not cause the motor to provide a greater amount of assist than an amount requested, as detected by the other sensor.

Growing community of inventors

Walled Lake, MI, United States of America

Philip A Gaubis