It is very good with the newely implemented software alogaritm to compute the percentage of slippage as a new feature of slip-detection.

However, I think that the rover must not pull out and try to another way. Hence, the reason is that after the first intent, the trail is already paved (not always but it happens often and after a visual inspection will decide if or not for the second intent) and so the rover can go up on the same trail with fewer slip or nothing. Thus, the software alogarithm of slip-detection must be reset before the second intent. Hope this new technique is very common for the off road. The first ones in front has greater effort to open a new sand trail and the followers on the same trail goes much easier.

Rodolfo

Here's a question: how fast can the rovers go? I don't mean per Sol, but per hour (as in MPH, KPH, etc). A s-l-o-w grind into a dune would be quite different from a fast burst into a, you know, wossisname, ripple...

Bob Shaw

Good point RNeuhaus, however, just to clarify -- the backing-out manuever was commanded by the engineers, not by the rover itself. Once it detects the excessive slippage it just stops the drive and sits there waiting commands from the masters.

Bob, the rovers go very slow, with a top speed of a whopping 5 centimeters (2 inches) per second (link).

Yes you are entirely correct Pando, its a crawling pace with a negligible forward momentum. So if the rover loose traction it will start to dig in.

S-L-O-W is all they can do. Top speed is like a quarter mile per hour.

To say slow is an understatement. 2inches/sec is 10 feet/minute (5cm/sec=3m/minute). I've tried driving a riding lawnmower at that velocity and it's glacial. I guess we all have this mental image of tour intrepid explorers bounding across the Martian landscape when in reality we know that they are creeping.

The average speed make the total odometry an impressive feat.

--Bill

Bill,

here is your GIF animation of the left front wheel of Opportunity.

Sol 605 L0 front Hazcam.

jvandriel

and here is the anomation of the Right front wheel.

Sol 605.

jvandriel

Here is a single animation ( not a loop ) from the Right front wheel.

The animation starts at the top of the Dune and ends at the bottom of that Dune on the

bedrock.

jvandriel

Pando:

Thank you for pointing out the WEB page about the Rover technical information capabilities. The rover's speed is 180 meters / hour. The offroad capabilities become even tougher. For a slow ones, It is better to pull out and try to attack in another angle with lower height and softer slope. The solution to that problem is to increase contact area surface of wheels to compensate of its very slow speed.

Rodolfo

What I've taken from the discussion regarding MER speed (or, more properly 'slow'!) is that our learned responses on Earth are not especially useful on Mars - and that the MERs may not even tell us all that much about locomotion for future rovers... ...speaking of which, anyone know what sort of driving speeds are expected from future vehicles?

Bob Shaw

I think the speed is mostly determined by the rovers ability to see and analyse their surroundings, and their overall progress rate is clearly primarily dependant on the fact that they still need to be "driven", that introduces days of latency as the drivers and planners need to analyse each new location and decide what to do next. The imaging and processing constraints will probably improve by a factor of 100 for MSL but even so I don't think it will actually be able to progress much faster than Oppy did when it was ripping south at 100m/Sol.

The DARPA Grand Challenge seems to have achieved it's aim of vastly improving the quality of autonomous vehicle capability. So far at least four vehicles have crossed the line completing the 132 mile traverse in under 10 hours.

That's about 13mph. 100x MER speed is about 18kph so it would seem that at least on earth 100x MER speed for a "rover" is now realistic.

Today is drive day.

Sol Seq.Ver ETH ESF EDN EFF ERP Tot Description
--- -------- --- --- --- --- --- ---- -----------
608 p0755.03 0 0 0 0 0 0 navcam_5x1_az_270_3_bpp
608 p1201.03 0 0 0 0 0 0 front_haz_penultimate_1_bpp_crit16
608 p1214.05 0 0 0 0 0 0 front_haz_ultimate_4bpp_pri15
608 p1235.04 0 0 0 0 0 0 front_hazcam_stumble_0.5_bpp_pri_56
608 p1235.04 0 0 0 0 0 0 front_hazcam_stumble_0.5_bpp_pri_56
608 p1235.04 0 0 0 0 0 0 front_hazcam_stumble_0.5_bpp_pri_56
608 p1235.04 0 0 0 0 0 0 front_hazcam_stumble_0.5_bpp_pri_56
608 p1235.04 0 0 0 0 0 0 front_hazcam_stumble_0.5_bpp_pri_56
608 p1311.06 0 0 0 0 0 0 rear_haz_ultimate_1_bpp_crit18
608 p1335.03 0 0 0 0 0 0 rear_hazcam_stumble_0.5_bpp_pri_56
608 p1335.03 0 0 0 0 0 0 rear_hazcam_stumble_0.5_bpp_pri_56
608 p1335.03 0 0 0 0 0 0 rear_hazcam_stumble_0.5_bpp_pri_56
608 p1335.03 0 0 0 0 0 0 rear_hazcam_stumble_0.5_bpp_pri_56
608 p1335.03 0 0 0 0 0 0 rear_hazcam_stumble_0.5_bpp_pri_56
608 p1655.01 0 0 0 0 0 0 navcam_5x1_az_90_1_bpp
608 p2393.06 0 0 0 0 0 0 pancam_drv_dir_7x1_L2R2
608 p2600.07 0 0 0 0 0 0 pancam_tau
608 p2600.07 0 0 0 0 0 0 pancam_tau
608 p2627.01 0 0 0 0 0 0 pancam_sky_radiance_thumbs_L457R247
608 Total 0 0 0 0 0 0

I still reckon there was no slip. I think that this is the front right wheel track at the point of backing out, which shows that the wheel was not slipping.