Other

Advanced Sensor Technology Limited

Hemy8 Sa

Melius Sa

General Electric Company

Sylvac Sa

Meyer, Hans Ulrich

Hans Ulrich Meyer

Walter Umbricht

Benno Basler

David Wäckerlin

Daniel Clerc

Daniel Rawyler

An inductive absolute position sensor has a scale with planar conducting features on a pattern repeating every spatial period Talong a measuring path and a reading head with planar windings: multipolar sine and cosine sense windings of spatial period T=T/M, M an integer, a unipolar first drive winding surrounding the sense windings and a multipolar second drive winding of spatial period T/N along the measuring path, with N=M&#xb1;1. An electronic circuit makes a first mode measurement using the first drive winding and a second mode measurement using the second drive winding. The absolute position in a range Tis computed from both modes' measurements. The sensor may be as compact as the incremental sensor it replaces, as the scale pattern and second drive winding needed for making it absolute do not need extra space.

Inductive absolute position sensor

A capacitive imaging method or device using an array of row electrodesand column electrodeson a substrate, wherein cross-capacitance between row and column electrodes is obtained from row electrodeself-capacitance measured with the remaining electrodes grounded, column electrodeself-capacitance measured with the remaining electrodes grounded, and combined row and column electrode self-capacitance measured with the remaining electrodes grounded. A preferred embodiment is a hand-held wall scanner for detecting hidden features having a two-dimensional display the size of the array and located over it. Hidden features influencing row-to-column cross-capacitances are thus imaged in real size and at their real location.

Method of measuring capacitance of row and column electrodes of capacitive imaging device

A feeler gauge includes multiple feeler blades and an optical sensor. Each of the multiple feeler blades rotates about an axis between a measuring position and a non-measuring position. Each of the multiple feeler blades includes a measurement portion configured to be inserted into a gap to be measured and a proximal end having an indication of thickness of the respective feeler blade thereon. The optical sensor optically determines one or more of the multiple feeler blades that are deployed in the measuring position from the respective indications of thickness of each of the one or more feeler blades.

Digital wireless feeler gauge

A capacitive position sensing system has a pickup electrode, a shield electrode partially enclosing the pickup electrode, and an essentially grounded relatively movable target near the pickup electrodes; a capacitance-to-digital converter, and switching means for connecting each electrode in turn to the converter input or to ground. A capacitive position sensing method in the system includes measuring a first capacitance Cof at least one pickup electrode set with the shield electrode set grounded, measuring a second capacitance Cof at least one shield electrode set with the pickup electrode set grounded, and measuring a third capacitance Cof the pickup electrode set and the shield electrode set connected together; and calculating a first result indicating a position of a target using the first capacitance C, the second capacitance Cand the third capacitance C

Position sensing device and method using self-capacitance

A pulsed coil drive for a sampled inductive transducer has at least one drive coil connected in a series circuit with a capacitor having a first terminal connected to the negative terminal of a voltage source. The series circuit is normally open during the intervals between pulses. Sampling occurs once per pulse. Each pulse's sampling interval is preceded by a pre-sampling interval and followed by a post-sampling interval. The supply voltage that is applied across the series circuit during both the pre- and post-sampling intervals is applied by switching a first terminal of the coil's free terminal to the voltage source's positive terminal through a p-channel MOSFET. During the sampling interval, the series circuit is shorted by switching the coil's free terminal to the voltage source's negative terminal through an n-channel MOSFET.

Pulsed coil drive circuit for a sampled inductive transducer

An inductive position sensor has a spatially periodic scale with a series of conducting or permeable features of pitch T and a reading head with drive windings and sense windings, facing the scale with a spatial period 2T along the scale. The windings are each divided in two identical winding elements,having the same relative location within two identical winding element patterns having a center-to-center distance along the scale of NT+T/2, N being an integer, and connected so that the winding element polarities in each winding are either opposed for drive windings and the same for sense windings or the same for drive windings and opposed for sense windings. Thereby, direct couplings in both patterns cancel each other, while the spatially periodic signals coupled via the scale reinforce each other.

Inductive position sensor

Indicator

The inductive position sensor includes a scale () with a series of conductive loops spaced out by a pitch T and a cursor () provided with conductors forming each a series of alternating hairpin turns spaced out by a pitch T, the inducing (to) and induced (to) cursor conductors are laid out in two separate interlaced conductor groups, coupling between inducing and induced conductors of the second group taking place only via the scale loops. Such a sensor is simple, robust, accurate, insensitive to external electromagnetic fields and tolerant of misalignment between cursor and scale.

Inductive position sensor with a cursor and a coupling scale

A measuring instrument comprises a column (10) on which is mounted a carriage (11) with a drive cursor (12) and a measuring cursor (20) sliding on the drive cursor (12) and carrying a measuring contact (24) and a measuring device (40). A measuring force device (25) is arranged between the two cursors and determines, thanks to a lever (26) a rest position and two measuring positions vertically upwardly or downwardly offset or corresponding to a predetermined measuring force on the member to be measured. A motor (15) displaces the drive cursor (12) and the position detector (36) permits measuring the relative position between the two cursors. A control unit (35) controls the speed and direction of rotation of the motor (15) as a function either of the signals (44) received from the position detector (36) or from two external contacts (42, 43). The carriage (11) is first displaced by means of the external contacts (42, 43) and as soon as the lag between the two cursors reaches an upper or lower limit, the control of the motor is effected as a function of the signals received from the position detector (36). There is thus obtained a double subjection of the speed of movement of the carriage and of the measuring force, permitting very precise and rapid measurements and rendering easy the measurement of profiles.

Instrument for measuring lengths or angles

The inductive displacement sensor includes a first element of cursor (31) and a second element or scale (32) exhibiting spatially periodic electromagnetic characteristics, such as windows (321) and traverses (322). The first element (31) has a series of windings, e.g., three interlaced meander windings (31A to 31C) and an electronic circuit being connected to the windings on the first element to bring about a current in at least one of the windings (31A) and to measure the influence due to the position of the second element's spatially periodic electromagnetic characteristics on the inductances of at least a part of the windings (31B, 31C) of the first element (31). Such a displacement sensor is simple, rugged, small, draws little current and is insensitive to water.

Inductive displacement sensor with a cursor and a movable coupling scale

The capacitance sensor (1) comprises a linear or curvilinear array of electrodes (10) connected to means generating on these electrodes (10) a spatially periodic electric potential pattern shifting by increments along said array. Electrodes (10) are disconnected in turn to act as momentarily receiving electrodes (10R), also according to a spatially periodic pattern, shifting by the same increments. Both patterns shift alternately, i.e. the shifts of one pattern taking place between the shifts of the other. A linear or curvilinear scale (2), with a periodic pattern of electrodes (20) or dielectric or conducting relief, facing the sensor, will thus create a periodic fluctuation of the signal coupled on the momentarily receiving electrodes. The relative position between scale (2) and sensor (1) may then be accurately determined by evaluating the phase, after demodulation, of said signal. As the sensor may be integrated on a semiconductor die and the scale may be very narrow, extreme miniaturization and low cost is given. (FIGS. 1a and 1b)

A capacitive position sensor has a scale (10), having hollow or raised topographical features, and a cursor (20) having an electrode array comprising at least two transmitting electrodes (21a, 21b) and at least one receiving electrode (21c) separated by shielding electrodes (21g). The coupling capacitances (Cac, Cbc) between transmitting and receiving cursor (20) electrodes are modified as a function of the position (x) of the scale topographic feature (11) relative to the cursor, the evaluation of the variation of the signals picked up by the receiving electrode permitting a precise measurement of the relative displacement between scale and cursor.

Capacitive position sensor including a scale with integral topographical

Capacitive position sensor with an electrode array cursor and

The capacitive detector of position between two supports (10 and 30) comprises a series of electrodes (11) on support (10) and a series of electrodes (13) on support (30). The electrodes (13) of support (30) and electronic circuitry (21) are formed on the lower face of an integrated circuit substrate (20) constituting the electronic part intended for the application of incremental potentials to the electrodes (13).

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Morges, Switzerland

Hans Ulrich Meyer