RF POSITION-SENSING AND CONTROL SYSTEM

• US 3,623,101 A
• Filed: 07/11/1968
• Issued: 11/23/1971
• Est. Priority Date: 07/11/1968
• Status: Expired due to Term

• Current Assignee: Earl Raymond Kreinberg, Robert Karl Grebe
• Original Assignee: Earl Raymond Kreinberg, Robert Karl Grebe
• Inventors: Grebe, Robert Karl, Kreinberg, Earl Raymond
• Primary Examiner(s): Bennett, Jr., Rodney D.
• Assistant Examiner(s): Berger, Richard E.
• Application Number:
  US04/744,070
• Time in Patent Office: 1,230 Days
• Field of Search: 343/112,5PD 340/258C,259 318/16
• US Class Current: 342/450
• CPC Class Codes: G01S 11/023 using impedance elements varying with distance
• CPC Class Codes: G05D 15/01 characterised by the use of electric means

Abstract

Method and means are disclosed for sensing and detecting the position of a member by the effect of the member on the coupling between sensing elements separately connected to an RF transmitter and an RF receiver. The sensing elements are disposed to provide a degree of coupling therebetween related to the physical position of the member between such elements and to produce a sensed signal indication of either member position or member presence. The sensed signal is detected and applied to a utility device which may be in the form of an alarm, counter indicator, recorder, or in the form of a motor to provide a feedback signal capable of altering the position of the sensed member. In one form of the invention a wire or strip feeding control apparatus senses the position of a free-hanging span of the wire or strip to develop a reel-motor control signal and adjust the fall or sag of the span, thereby controlling feed rate and wire or strip tension. For nonconductive sensed members or for fluids a conductive element is carried in a frame of dielectric material in the plane of the sensing element coupling which restricts the sensed member to movement along an axis bisecting the zone of coupling of the transmitting and receiving antenna elements.

Claims

1. In a method of sensing the position of a member, the steps comprising generating an RF signal, supplying said signal to one of a pair of sensing elements to provide a coupling field therebetween traversed by said member, detecting the degree of coupling between said sensing elements as affected by the position of said member therebetween, including the reception and detection of a signal based on said coupling through receiver elements, and supplying the detected signal to a utility device, wherein said utility device includes means to control movement of said member and the detected signal is utilized to alter the position of said member to a predetermined position between said sensing elements.

2. In a method of sensing the position of a member, the steps comprising:

generating an RF signal;

supplying said signal to one of a pair of sensing elements positioned with the length axes thereof disposed at an angle to provide a coupling field therebetween which increases along the length of said elements and which is traversed by said member;

detecting the degree of coupling between said sensing elements as affected by the position of said member therebetween, including receiving a signal based on said coupling through the other of said sensing elements and detecting said signal with detecting means, the detected signal thereby having a linear characteristic; and

supplying the detected signal to a utility device.

3. In a method of sensing the position of a member, the steps comprising:

generating an RF signal;

supplying said signal to one of a pair of sensing elements to provide a coupling field therebetween traversed by said member;

detecting the degree of coupling between said sensing elements as affected by the position of said member therebetween, including receiving a signal based on said coupling through the other of said sensing elements and detecting said signal with detecting means; and

supplying the detected signal to a utility device, wherein said utility device includes means to control movement of said member and the detected signal is utilized to alter the position of said member to a predetermined position between said sensing elements.

4. In an apparatus for sensing the presence or the position of a moving member, a sensing structure including a first sensing element and a second sensing element positioned to provide a coupling therebetween affected by movement of the member along a predetermined path, which coupling varies along the length of said sensing elements, an RF transmitter connected to the first sensing element of said sensing structure to generate a signal providing said coupling, and a receiver connected to the said second sensing element including means responsive to the variation in coupling for providing a detected signal as an indication of the moving member.

5. In an apparatus for sensing the position of a moving member, a sensing structure including a first sensing element and a second sensing element positioned to provide a coupling therebetween affected by a path of movement of member, an RF transmitter connected to the first sensing element of said sensing structure to generate a signal providing said coupling, a receiver connected to the said second sensing element operable to provide a detected signal representative of the position of a member within the coupling between said sensing elements, and means positioning said sensing elements with the length axes thereof disposed at an angle to provide a coupling which increases along the length of the sensing elements to provide a linear characteristic to said detected signal as a member moves between said sensing elements.

6. In an apparatus for sensing a moving member, a sensing structure including a first sensing element and a second sensing element positioned to provide a coupling therebetween affected by movement of the member along a path, an RF transmitter connected to the first sensing element of said sensing structure to generate a signal providing said coupling, means for positioning said sensing elements with the length axes thereof substantially parallel to provide a coupling which is caused to vary in a predetermined manner by movement of a member into, through, and out of said coupling, and receiver meAns connected to the said second sensing element including means responsive to said variation in coupling for providing a detected pulse waveform characteristic as an indication of the moving member.

7. In an apparatus for sensing the position of a moving member, a sensing structure including a first sensing element and a second sensing element positioned to provide a coupling therebetween affected by a path of movement of the member, an RF transmitter connected to the first sensing element of said sensing structure to generate a signal providing said coupling, a receiver connected to the second sensing element operable to provide a detected signal representative of the position of a member within the coupling between said sensing elements, and means responsive to the detected signal from said receiver for utilizing the detected signal, said utilizing means including a motor connected to drive said member responsive to said signal to a predetermined position between said sensing elements.

8. In an apparatus for sensing the position of a moving member, a sensing structure including a first sensing element and a second sensing element positioned to provide a coupling therebetween affected by a path of movement of the member, an RF transmitter connected to the first sensing element of said sensing structure to generate a signal providing said coupling, a receiver connected to the said second sensing element operable to provide a detected signal representative of the position of a member within the coupling between said sensing elements, means responsive to the detected signal from said receiver for utilizing the detected signal, and means to confine them member to movement in a plane of coupling between said sensing elements.

9. In an apparatus for sensing the position of a moving member, a sensing structure including a first sensing element and a second sensing element positioned to provide a coupling therebetween affected by a path of movement of the member, an RF transmitter connected to the first sensing element of said sensing structure to generate a signal providing said coupling, a receiver connected to the said second sensing element operable to provide a detected signal representative of the position of a member within the coupling between said sensing elements, a conductive member connected to said moving member, and means to confine said conductive member for sliding movement within the coupling between said sensing elements.

10. In a method of sensing the position of a member, the steps comprising:

generating an RF signal;

supplying said RF signal to one of a pair of spaced-apart sensing elements to provide a coupling field therebetween, said coupling field varying along the length of said sensing elements in accordance with the position of said member therebetween;

detecting the degree of coupling between said sensing elements as affected by the position of said member therebetween, including receiving a signal based on said coupling through the other one of said sensing elements and detecting said signal with detecting means, the detected signal thereby providing an indication of presence or position of the member; and

supplying the detected signal to a utility device.