Position feedback system and method for use thereof

• US 6,625,517 B1
• Filed: 06/02/2000
• Issued: 09/23/2003
• Est. Priority Date: 04/26/1999
• Status: Expired due to Term

• Current Assignee: Tetra Laval Holdings & Finance SA (Tetra Laval Holdings BV)
• Original Assignee: Tetra Laval Holdings & Finance SA (Tetra Laval Holdings BV)
• Inventors: Ortiz, Mark S., Bogdanov, Emil D., Bologna, Gregory A., Arms, Donald A., Restle, Randall C.
• Primary Examiner(s): Picard, Leo
• Assistant Examiner(s): RODRIGUEZ, PAUL L
• Application Number:
  US09/587,365
• Time in Patent Office: 1,208 Days
• Field of Search: 700/56, 700/57, 700/61, 700/58, 700/64, 700/302, 700/275, 700/186, 700/190-194, 702/150, 324/207.13, 324/207.14, 324/207.21
• US Class Current: 700/193
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/3656 being a layer of a multilayer part to be joined, e.g. for joining plastic-metal laminates
• CPC Class Codes: B29C 65/3668 characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils
• CPC Class Codes: B29C 65/368 with a polymer coating
• CPC Class Codes: B29C 65/7451 the severing tool and the welding tool being movable with respect to one-another
• CPC Class Codes: B29C 65/7894 of continuously moving sheets or webs
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/1162 Single bevel to bevel joints, e.g. mitre joints
• CPC Class Codes: B29C 66/133 Fin-type joints, the parts to be joined being flexible the parts to be joined being rigid B29C66/1312
• CPC Class Codes: B29C 66/3452 Making complete joints by combining partial joints
• CPC Class Codes: B29C 66/4312 for making flat seams in tubular or hollow articles, e.g. transversal seams
• CPC Class Codes: B29C 66/4322 by joining a single sheet to itself B29C66/4332 takes precedence
• CPC Class Codes: B29C 66/49 Internally supporting the, e.g. tubular, article during joining B29C66/63 takes precedence
• CPC Class Codes: B29C 66/72321 consisting of metals or their alloys
• CPC Class Codes: B29C 66/72328 Paper
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/8122 characterised by the composition of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
• CPC Class Codes: B29C 66/81419 and flat
• CPC Class Codes: B29C 66/81427 comprising a single ridge, e.g. for making a weakening line; comprising a single tooth
• CPC Class Codes: B29C 66/8161 : said pressing elements being supported or backed-up by springs or by resilient material
• CPC Class Codes: B29C 66/8167 : Quick change joining tools or surfaces
• CPC Class Codes: B29C 66/8181 : characterised by the cooling constructional aspects
• CPC Class Codes: B29C 66/8226 : Cam mechanisms; Wedges; Eccentric mechanisms
• CPC Class Codes: B29C 66/82263 : Follower pin or roller cooperating with a groove
• CPC Class Codes: B29C 66/8242 : Pneumatic or hydraulic drives using fluid pressure directly acting on the parts to be joined B29C66/8266
• CPC Class Codes: B29C 66/8244 : magnetically driven
• CPC Class Codes: B29C 66/83413 : cooperating rollers, cylinders or drums
• CPC Class Codes: B29C 66/83415 : the contact angle between said rollers, cylinders or drums and said parts to be joined being a non-zero angle B29C66/83433 takes precedence
• CPC Class Codes: B29C 66/8351 : Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws
• CPC Class Codes: B29C 66/83523 : Cooperating jaws mounted on cooperating bands or belts and moving in a closed path
• CPC Class Codes: B29C 66/83533 : Cooperating jaws mounted on cooperating chains and moving in a closed path
• CPC Class Codes: B29C 66/8491 : welding through a filled container, e.g. tube or bag
• CPC Class Codes: B29C 66/872 : Starting or stopping procedures
• CPC Class Codes: B29C 66/93441 : the speed being non-constant over time
• CPC Class Codes: B29C 66/93451 : by controlling or regulating the rotational speed, i.e. the speed of revolution
• CPC Class Codes: B29C 66/9392 : in explicit relation to another variable, e.g. speed diagrams
• CPC Class Codes: B29C 66/98 : Determining the joining area by using markings on at least one of the parts to be joined
• CPC Class Codes: B29K 2705/02 : Aluminium
• CPC Class Codes: B29K 2909/02 : Ceramics
• CPC Class Codes: B65B 51/30 : Devices, e.g. jaws, for applying pressure and heat, e.g. for subdividing filled tubes
• CPC Class Codes: B65B 9/20 : the webs being formed into tubes in situ around the filling nozzles
• CPC Class Codes: G05B 19/00 : Programme-control systems

Abstract

The present invention is directed to a machine with a position feedback system and a method for use thereof. The machine includes at least one movable element mounted for movement on a path and at least one programmable controller. The machine further includes at least two absolute or magnetostrictive sensors or the machine includes an absolute sensor and a non-absolute sensor. The programmable controller uses positional information from the sensors to determine the position of the movable elements on the path and control the movable elements. The method includes determining a known position for the movable elements, linking at least two magnetostrictive sensors into one virtual sensor, and/or performing commutation alignment for the movable elements. Determining the position and commutation alignment can occur when the movable elements are stationary or moving.

Claims

1. A machine comprising:

at least two closed paths defined by at least two separate guide members spaced from one another;

at least two magnetostrictive sensors disposed on each path;

at least one movable element mounted for movement on each path;

at least one programmable controller operatively associated with each sensor and each movable element, wherein the controller receives at least one signal from one of the sensors which is representative of at least one control variable of at least one of the associated movable elements.

2. The machine of claim 1, wherein a plurality of movable elements are mounted to be movable and positionable independently of one another on each path.

3. The machine of claim 1, wherein the magnetostrictive sensors at least partially overlap.

4. The machine of claim 1, further including three or more magnetostrictive sensors.

5. The machine of claim 1, wherein the magnetostrictive sensors have different lengths.

6. The machine of claim 1, wherein at least one movable element includes a magnet operatively associated with the sensors.

7. The machine of claim 1, wherein each magnetostrictive sensor has a head and a waveguide electrically connected thereto, the head being electrically connected to the controller.

8. The machine of claim 7, wherein the heads of the magnetostrictive sensors are spaced apart from one another.

9. A machine comprising:

at least two closed paths defined by at least two separate guide members spaced from one another;

at least one magnetostrictive sensor disposed on each paths;

at least one non-absolute sensor disposed on each paths;

at least one movable element mounted for movement on each path;

at least one programmable controller operatively associated with each sensor and each movable element, wherein the controller receives at least one signal from one of the sensors which is representative of at least one control variable of at least one of the associated movable elements.

10. The machine of claim 9, wherein the non-absolute sensor(s) is a step and direction type of sensor or an incremental type of sensor.

11. The machine of claim 10, wherein the non-absolute sensor(s) is at least one Hall Effect sensor.

12. The machine of claim 9, further including a plurality of non-absolute sensors.

13. The machine of claim 12, further including a plurality of magnetostrictive sensors.

14. The machine of claim 9, wherein the movable element includes a first magnet operatively associated with the magnetostrictive sensor(s) and an actuation device operatively associated with the non-absolute sensor(s).

15. The machine of claim 14, wherein the actuation device is a second magnet.

16. The machine of claim 9, wherein each magnetostrictive sensor has a head and a waveguide electrically connected thereto, the head being electrically connected to the controller.

17. A method for using at least two magnetostrictive sensors on each of at least two closed paths defined by at least two separate guide members spaced from one another, comprising the steps of:

providing at least one moveable element for each path, that is movable on the path, and each movable element includes at least one magnet;

providing at least two magnetostrictive sensors on each path for outputting positional information on each movable element, each magnetostrictive sensor is operatively associated with the at least one magnet;

providing a first programmable controller electrically connected to the sensors; and

using the positional information from each sensor so that the first programmable controller links the sensors into a single, continuous, virtual sensor on each path.

18. The method of claim 17, further comprising the step of providing a second programmable controller, wherein the second programmable controller uses the virtual sensor to control the movement of the movable elements.

19. The method of claim 18, wherein the first programmable controller is at least one digital signal processor and the second programmable controller is a motion controller.

20. The method of claim 18, further including using the positional information to perform commutation alignment, when the associated movable element is stationary.

21. The method of claim 17, wherein the step of using the positional information further includes determining a known position for each movable element on each path, when the associated movable element is stationary.

22. The method of claim 17, wherein the step of using the positional information further includes determining a known position for each movable element on each path, when the associated movable element is moving.

23. A method for using positional information on at least one movable element disposed on a closed path defined by a guide member, comprising the steps of:

providing at least one movable element that is movable on the path, and each movable element includes at least one magnet;

providing at least one magnetostrictive sensor on the path for outputting positional information on each movable element, each magnetostrictive sensor is operatively associated with the at least one magnet;

providing a first programmable controller electrically connected to each sensor;

using the positional information from each sensor; and

wherein the step of providing at least one movable element further includes providing a servo-motor with each movable element, and the step of using the positional information includes performing commutation alignment on each servo-motor using the positional information from each sensor.

24. The method of claim 23, wherein the step of performing commutation alignment occurs when the associated movable element is stationary.

25. The method of claim 23, wherein the step of using the positional information further includes determining a known position for the movable element on the path, when the associated movable element is stationary.

26. The method of claim 23, further including providing at least one non-absolute sensor on the path and determining a known position for each movable element using information from each non-absolute sensor.