Optical sensing, non-tethered location monitoring systems and methods of use
Provided is a system for optical sensing. The system may include a linear motor, which may include a first member and a second member. The second member may be movable relative to the first member. At least one optical sensor may be disposed with the first member. A target may be disposed with the second member. The target may include at least one pattern of alternating first areas and second areas. The first areas may include a first color. The second areas may include a second color different than the first areas. The target may be positioned to overlap with an optical path of the at least one optical sensor as the second member moves relative to the first member. A method for optical sensing and a method for making a system for optical sensing are also disclosed.
1. A system for optical sensing, comprising:
a linear motor comprising a stator and a linear permanent magnet carrier movable relative to the stator;
at least one optical sensor disposed with the stator; and
a target disposed with the linear permanent magnet carrier, the target comprising at least one pattern of alternating first areas and second areas, the first areas comprising a first color, the second areas comprising a second color different than the first areas, the target positioned to overlap with an optical path of the at least one optical sensor as the linear permanent magnet carrier moves relative to the stator.
2. The system of claim 1 , wherein the stator is attached to at least a portion of a track, and wherein the linear permanent magnet carrier is attached to a conveyance.
3. The system of claim 1 , wherein the linear permanent magnet carrier comprises at least two permanent magnets arranged in alternating polarity, and wherein the stator comprises stator coils.
4. The system of claim 1 , wherein the linear permanent magnet carrier is separated from the stator by an air gap, wherein the target and the at least one optical sensor face the air gap, wherein the stator defines a first recess to at least partially receive the at least one optical sensor, wherein the linear permanent magnet carrier defines a second recess to at least partially receive the target, and wherein the at least one optical sensor and the target do not entirely protrude into the air gap when received in the first recess and the second recess, respectively.
5. The system of claim 1 , wherein the at least one optical sensor comprises a first optical sensor and a second optical sensor, and wherein the at least one pattern comprises a first pattern and a second pattern, the first pattern positioned to overlap with the optical path of the first optical sensor as the linear permanent magnet carrier moves relative to the stator, and the second pattern positioned to overlap with the optical path of the second optical sensor as the linear permanent magnet carrier moves relative to the stator.
6. The system of claim 5 , wherein the first pattern is offset from the second pattern in a direction of motion of the linear permanent magnet carrier relative to the stator.
7. The system of claim 1 , wherein the target comprises a mask comprising the second color, the mask affixed on a portion of the linear permanent magnet carrier, the mask defining a plurality of holes corresponding to the first areas, wherein the portion of the linear permanent magnet carrier comprises the first color.
8. The system of claim 1 , wherein the at least one optical sensor comprises at least one light emitting sensor.
9. The system of claim 8 , wherein the at least one light emitting sensor comprises a laser and an optical receiver.
10. The system of claim 8 , wherein the at least one light emitting sensor comprises a fiber optic transmitter and a fiber optic receiver.
11. The system of claim 10 , wherein the fiber optic transmitter comprises a first optical fiber coupled to a light emitting diode (LED), and wherein the fiber optic receiver comprises a second optical fiber coupled to an optical receiver.
12. The system of claim 11 , wherein the first optical fiber and the second optical fiber are coaxial.
13. The system of claim 1 , further comprising at least one amplifier coupled to the at least one optical sensor, each amplifier configured to amplify an output signal of a respective one of the least one optical sensor.
14. The system of claim 13 , further comprising a controller coupled to the at least one amplifier, the controller configured to receive the output signal of each optical sensor as amplified by the at least one amplifier, the controller configured to determine at least one of a position or a velocity of the linear permanent magnet carrier relative to the stator based on the output signal of each optical sensor.
15. The system of claim 14 , wherein the at least one optical sensor comprises a first optical sensor and a second optical sensor, wherein the at least one pattern comprises a first pattern and a second pattern, the first pattern positioned to overlap with the optical path of the first optical sensor as the linear permanent magnet carrier moves relative to the stator, and the second pattern positioned to overlap with the optical path of the second optical sensor as the linear permanent magnet carrier moves relative to the stator, wherein the first optical sensor produces a first output signal in response to sensing the first pattern of the target, wherein the second optical sensor produces a second output signal in response to sensing the second pattern of the target.
16. The system of claim 14 , wherein the controller is further configured to control the linear motor based on the at least one of the position or velocity.
17. A method for optical sensing, comprising:
sensing, with at least one optical sensor disposed with a stator of a linear motor, a target, the target disposed with a linear permanent magnet carrier of the linear motor, the linear permanent magnet carrier movable relative to the stator, the target comprising at least one pattern of alternating first areas and second areas, the first areas comprising a first color, the second areas comprising a second color different than the first areas, the target positioned to overlap with an optical path of the at least one optical sensor as the linear permanent magnet carrier moves relative to the stator;
generating, with each optical sensor, an output signal based on sensing the target; and
determining, with a controller coupled to the at least one optical sensor, at least one of a position or a velocity of the linear permanent magnet carrier relative to the stator based on the output signal of each optical sensor.
18. The method of claim 17 , further comprising controlling the linear motor based on the at least one of the position or velocity.
19. A method of making a system for optical sensing, comprising:
disposing at least one optical sensor with a stator of a linear motor; and
disposing a target with a linear permanent magnet carrier of the linear motor, the linear permanent magnet carrier movable relative to the stator, the target comprising at least one pattern of alternating first areas and second areas, the first areas comprising a first color, the second areas comprising a second color different than the first areas, the target positioned to overlap with an optical path of the at least one optical sensor as the linear permanent magnet carrier moves relative to the stator.
20. The method of claim 19 , wherein the linear permanent magnet carrier is separated from the stator by an air gap,
wherein the target and the at least one optical sensor face the air gap,
wherein disposing the at least one optical sensor with the stator comprises forming, in the stator of the linear motor, a first recess to at least partially receive the at least one optical sensor,
wherein disposing the target with the linear permanent magnet carrier comprises forming, in the linear permanent magnet carrier of the linear motor, a second recess to at least partially receive the target, and
wherein the at least one optical sensor and the target do not entirely protrude into the air gap when received in the first recess and second recess, respectively.
21. The method of claim 19 , wherein the at least one optical sensor comprises a first optical sensor and a second optical sensor, wherein the at least one pattern comprises a first pattern and a second pattern, the first pattern positioned to overlap with the optical path of the first optical sensor as the linear permanent magnet carrier moves relative to the stator, and the second pattern positioned to overlap with the optical path of the second optical sensor as the linear permanent magnet carrier moves relative to the stator, and wherein the first pattern is offset from the second pattern in a direction of motion of the linear permanent magnet carrier relative to the stator.
22. The method of claim 19 , wherein the target comprises a mask comprising the second color, the mask defining a plurality of holes corresponding to the first areas, wherein a portion of the linear permanent magnet carrier comprises the first color, and wherein disposing the target with the linear permanent magnet carrier comprises affixing the mask on the portion of the linear permanent magnet carrier.
23. The method of claim 19 , further comprising:
coupling at least one amplifier to the at least one optical sensor, each amplifier configured to amplify an output signal of a respective one of the least one optical sensor; and
coupling a controller to the at least one amplifier, the controller configured to receive the output signal of each optical sensor as amplified by the at least one amplifier, the controller configured to determine at least one of a position or a velocity of the linear permanent magnet carrier relative to the stator based on the output signal of each optical sensor.