• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 522 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LDC1614: Proximity sensors support and alternatives

Federico Papparotto35
Prodigy 200 points
Part Number: LDC1614
Other Parts Discussed in Thread: OPT3101, TIDA-00663

Dear team,

my customer needs a proximity sensor to measure dynamic distance of one machine's part in respect to another one. Stroke is 30mm and resolution 0.1mm. Customer tried to use LDC1614. Since everything around is made by Aluminium, the device's response is really disturbed by every movement close to the coils - it's enough to move your hand 10cm close to the coil and you get a wrong reading. 

a) Is there a way to reduce this noise with LDC1614?

b) can we suggest another device from our Sensors portfolio that does not suffer when there is environmental disturbances?

Thanks,

Federico

  • 0
    TI__Genius 17440 points
    Hello Federico,

    The LDC1614 is especially sensitive to metal movement in its sensing area. It is possible to use ferrite shielding on unintended metal targets. You can also use a reference sensor that does not see the target movement to compensate for environmental shifts. The reference sensor approach would only work if the target sensor and reference sensor saw the same environmental shifts.

    We don't have a device that is immune to environmental disturbances. The LDC devices will be sensitive to changes in nearby metal objects and the FDC devices will be sensitive to changes in all nearby objects. The best method to compensate for environmental disturbances is the reference sensor.

    Best Regards,
  • 0 in reply to Kristin Jones93
    TI__Prodigy 200 points
    Hello Kristin,

    thank you for your reply. One more question: are there other specialty sensors not affected by environmental disturbances that we can suggest to customer?

    Thank you,
    Federico, TSR
  • 0 in reply to Federico Papparotto35
    TI__Genius 17440 points
    Hello Federico,

    We do not have any other sensors that would be unaffected by environmental disturbances. All of the capacitive and ultrasonic sensors will detect all objects within their sensing range and the inductive sensors will detect all metal objects within their sensing range.

    Best Regards,
  • 0 in reply to Kristin Jones93
    TI__Prodigy 200 points
    Hello Kristin,

    thanks for your clarification. Which sensor (optical, inductive, etc) would be the most immune in metal environment? My customer needs a proximity sensor to measure dynamic distance of one machine's part in respect to another one. Stroke is 30mm and resolution 0.1mm.

    Sorry to bother you but I'd like to understand it better.

    thanks,
    Federico
  • 0 in reply to Federico Papparotto35
    TI__Genius 17440 points
    Hello Federico,

    I don't support optical sensors, so I'm not sure how they would fare in a metal environment. You may wish to post a new E2E question about optical sensors specifically. Inductive sensors can work in environments with a significant amount of metal if the metal is either shielded or stationary and far away from the sensor. In general, most types of sensing that do not specifically detect metal would be more robust in a metal environment than inductive sensing. Inductive sensing is immune to environmental contaminants like dust and water that could affect other sensors (like ultrasonic or capacitive). If these other environmental contaminants aren't a concern in this application, capacitive sensing with the FDC2x1y devices and using a reference sensor might also be able to achieve the 30mm range and 0.1mm resolution.

    Best Regards,
  • 0 in reply to Federico Papparotto35
    TI__Intellectual 1365 points

    Hi,

    in general optical sensors will be immune to metal environment. The optics can be designed in a way to only "look" at one specific point.

    One example for this can be the OPT3101, this has an overall range of 15 m with 16 bit accuracy, resulting in 0.2 mm resolution.

    Another optical approach is to measure the time of flight of a single pulse, as it is done on TIDA-00663. This design measures the time of a single laser pulse with a resolution of 55 ps, which results in 1.6 mm.

    I would recommend you to have a look at the mmWave sensors, these can also be used for distance measuring and can achieve sub millimeter resolution.

    Have a look here: 

    http://www.ti.com/sensors/mmwave/what-is-mmwave.html 

    and here:

     http://dev.ti.com/tirex/content/mmwave_industrial_toolbox_3_4_0/labs/lab0026_vital_signs_68xx/docs/vital_signs_68xx_DevelopersGuide.html

    Best regards,

    Steffen