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naseeamFlag for United States of America

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Gearing of Stow Motors are protected by a clutch ?

The application is Third row SUV Power Folding Seats.  They are one-touch automated Power Folding Seats.  Touch of button folds or unfolds the seat.  A embedded control module is connected to DC brush motors.  Obstacle Detection Algorithm is running in the control module.  

This is closed loop control system.  Control module controls motors and motors provide hall pulses to the control module.

Please try to explain following statement:

"Since the gearing of the stow motors are protected by a clutch, it’s not possible to use motor stall to detect the end positions STOW and TAILGATE - resulting in the need to utilize the obstacle detection algorithm to detect these positions."



What are STOW and TAILGATE positions?
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d-glitch
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STOW and TAILGATE positions are the ends of the range, fully down (stowed) and fully up (toward the tailgate) respectively.

Frequently they let the motor run against a hard stop and detect the increase in current to indicate an obstacle.
That isn't possible here because there is a slip clutch to protect the gear train.  So the motor will never stall.
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Michael Best
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>>  utilize the obstacle detection algorithm to detect these positions

There is nothing here that tells you how the obstacle detection algorithm works, the type of sensor it uses to detect an obstacle, the response to a detected obstacle, or the procedure for recovering from a fault.

Are you trying to diagnose an existing problem?
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No, I'm not trying to diagnose an existing problem.  I'm just reading a paper on obstacle detection to gain some knowledge.

>> Since the gearing of the stow motors are protected by a clutch, it’s not possible to use motor stall to detect the end positions STOW and TAILGATE

Can you please answer above in bold format?  For Recliner Third Row Seats we use motor stall to reach folded position.  Hall pulses absent for certain amount of time indicates motor stall.  For Stow Motors why isn't it possible to use motor stall to detect end positions?  Is the stow motor not going to send absence of hall pulses when it reaches the ends?

What does above in bold exactly mean?  Please provide any basics on gearing and clutch needed to understand above.
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@ d-glitch
When it reaches either end of its range, or encounters an obstacle in the way, then the clutch will slip and the seat will stop, but the motor will continue to turn."
Huh! you are stating that the seat Recliner motor runs continuously.
That is completely incorrect.

@ naseeam
I had thought that I had answered your question clearly RE:
Michael-Best2015-04-28 at 01:20:11ID: 40746555

To add clarity to my previous comment:

The seat Recliner motor runs and never stalls, due to a clutch. but the motor is stopped by the Clutch slip sensor.
The Clutch slip sensor stops the seat Recliner motor when reaching:
1/ Stow position.
2/Tailgate position.
3/ An obstacle .

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If the excerpt of the paper had mentioned a clutch slip detector, I would agree with you.
But all they said was an obstacle detection algorithm.  Which suggests to me that they are doing it software.

>>  There is nothing here that tells you how the obstacle detection algorithm works, the type of sensor it uses,
       the response to a detected obstacle, or the procedure for recovering from a fault.

You may be right, but you are speculating.

>>  Huh! you are stating that the seat Recliner motor runs continuously.

Not exactly.  The clutch will slip as it is designed to, and the motor will run until the unspecified obstacle detection algorithm does its job.
@ d-glitch
I only offered my opinion / advice... sorry  :(
No problem.  I do think you are probably correct.  But they did mention a Hall sensor for the other motors, and didn't mention any sensor for this one.