rmp440le: immediately execute deceleration request

RMP 210, 220, 440LE, 440SE, 440 Omni
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woeto
Posts: 4
Joined: Mon Jun 10, 2013 3:52 pm

rmp440le: immediately execute deceleration request

Post by woeto »

Dear Segway-Team,
We did some tests with the rmp440le regarding the deceleration request. At different speeds we tested how long it takes for the vehicle to stop, after sending a deceleration request. Therefor we were using a deceleration rate of 3.9m/s^2.

The vehicle stops with the specified deceleration rate. But the deceleration request is not executed immediately. For us it seems that is takes approximately 1 second until the request is executed. Right after sending the request we can hear a beep signal coming from the segway, but the deceleration itself starts ~1 second afterwards.

Example: Vehicle moves with a velocity of 4m/s. After sending the deceleration request, the vehicle still moves for another second (4m) and then it starts to decelerate (2.1m). As a result we get a deceleration distance of 6m. We could have get less when the vehicle would have started the deceleration immediately.

Is there a way to get the deceleration executed immediately ?

ChrisC
Posts: 43
Joined: Fri Apr 20, 2012 8:22 am

Re: rmp440le: immediately execute deceleration request

Post by ChrisC »

If your Centralized Controller based platform has not been updated to the latest release binary files for the UIP and SP, please do so and then re-test to verify the RMP’s performance with respect to the observed behavior you described.

The latest release of the RMP_APP_INSTALLER package and instructions for how to install these updates are located here:
http://rmp.segway.com/viewtopic.php?f=9&t=70

Chris Crimmins
Segway Inc.

woeto
Posts: 4
Joined: Mon Jun 10, 2013 3:52 pm

Re: rmp440le: immediately execute deceleration request

Post by woeto »

Thanks for your information!
Our centralized Controller based platform version is based on Release 11-15-12 (SP: 1224, UIP: 1274).
I will update our system to the latest Release 04-08-13 (SP: 1228, UIP: 1275) and post the result asap.
Best!
Thomas

sdnalloh

Re: rmp440le: immediately execute deceleration request

Post by sdnalloh »

Has there been any progress on this issue?
Are you still seeing the delay, or is it all fixed?

-Greg

woeto
Posts: 4
Joined: Mon Jun 10, 2013 3:52 pm

Re: rmp440le: immediately execute deceleration request

Post by woeto »

I am sorry for the long pause on that issue. We updated the system to:
+ segway processor (SP): 1228 (comes with 04-08-13)
+ user interface processor (UIP): 1276 (comes with Release 04-08-13)
Unfortunately this update did NOT change the deceleration request behavior: When we send a deceleration request, we can hear the deceleration alarm immediately (some beeps) but the deceleration itself starts 1.1s after the alarm started. Actually for us it does look like the vehicle starts decelerating when the alarm ends?! So, we still have a delay of 1.1s between sending the deceleration request and the deceleration itself. Do you copy that behavior or do you have any suggestions how we could continue on that issue ?
Knowing this behavior we continue working in the meantime. But it is not really nice and in case of an emergency we could have saved quite a lot of space without that delay.
Best!
Thomas

phussey
Posts: 79
Joined: Fri Apr 20, 2012 8:12 am

Re: rmp440le: immediately execute deceleration request

Post by phussey »

The one second delay is intentional. The delay is to prevent a stepwise change in the velocity limit. When a DTZ response is issued the platform drops the speed limit to the current speed for 1 second and then slews the limit to zero at the specified deceleration rate.

This is important for dynamically stable platforms to prevent large transients, I can see however why it might not be necessary for statically stable systems.

Thank you for bringing attention to the issue; we will add it to the improvement list for the next release.
PATRICK HUSSEY
Principal Engineer

STANLEY INNOVATION, INC
www.stanleyinnovation.com

woeto
Posts: 4
Joined: Mon Jun 10, 2013 3:52 pm

Re: rmp440le: immediately execute deceleration request

Post by woeto »

Thanks for this information. For us it would be great to be able to change this delay via a parameter, maybe in the future version.
Greetings,
Thomas

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