Nanny Question

[Mo Lee]

How soon should the Nanny kick in? Coming home today after not being able to ride for a couple of weeks, first, I guess I twisted the throttle a little too hard for the damp salt and sand coated roads and the rear end kicked out about 6 inches I figured I just caught it in time before the nanny could, however up the road I was turning left not being too agressive and the rear end kicked out about 18 inches and still no nanny. Could it be my reactions are quicker than the nanny or is my nanny in hibernation for the winter. Maybe the Spyder knew I needed a fun ride.

 

[2spyders]

In my experience, it takes quite a bit for the traction control (I believe that's the part that controls rear wheel slip - when the engine cuts out) to kick in. I live on a gravel road, so my back tire slides all over the place and I've never had the traction control kick in there. The only time it's happened to me was when I took a sharp curve way too fast on a track a couple of times and the back tire started to slide around the corner.

That's different than the vss that applies the brakes to keep the front wheel from lifting. That happens a lot more often.

 

[NancysToy]

A lot of it depends on how well you control the throttle. If you keep the engine speed pretty low, so the rear tire barely exceeds the speed of the fronts, you can fishtail for well over 100 feet. I just did it in the snow the other day. As soon as you let the rpm come up, though, the TCS will kick in and cut the engine back.

 

[boborgera]

In my experience, it takes quite a bit for the traction control (I believe that's the part that controls rear wheel slip - when the engine cuts out) to kick in. I live on a gravel road, so my back tire slides all over the place and I've never had the traction control kick in there. The only time it's happened to me was when I took a sharp curve way too fast on a track a couple of times and the back tire started to slide around the corner.


Iv'e notice if i keep the front wheels straight it will fish tail,
If i turn the wheels when it's fish tailing the nanny will cut the engine.

 

[groundeffect]

Interesting thread.


When I did my test ride and first ever ride on the Spyder a few weeks ago, it was just slightly above freezing outside, but the roads where clear - no salt or ice.

During the test ride I did want to give it some throttle - small blasts to get an idea of the power. I was in second gear on a straight away and jammed the throttle wide open. I heard a roar and a slip on the back end, only slightly leading me off course, then the power suddenly dropped back and kept me able to ride in a straight line. The Nanny worked for me, and that is was I was checking for.

cheers.

 

[RoadHammer]

there's a steering sensor,,

if your wheels are turned ever so slightly and your back tire spins a little the nanny will kick in.

 

[Mo Lee]

Sounds like some are sensitive and some are not! Mine is not and I like it that way.hyea:

 

[mike3069]

A lot of it depends on how well you control the throttle. If you keep the engine speed pretty low, so the rear tire barely exceeds the speed of the fronts, you can fishtail for well over 100 feet. I just did it in the snow the other day. As soon as you let the rpm come up, though, the TCS will kick in and cut the engine back.

:agree:Also the rear tire can SLIDE sideways on a slippery surface and not spin at a different speed than the fronts, therefore not triggering the traction control even if they handlebars are turned.

 

[spyryder]

:agree:Also the rear tire can SLIDE sideways on a slippery surface and not spin at a different speed than the fronts, therefore not triggering the traction control even if they handlebars are turned.

Actually it should trigger the VSS. Lets say the YAW sensor detects a skid to the left and the handlebars are turned to the right....the steering angle sensor and Yaw sensor would work together to detect this skid and apply individual brakes as needed to bring the skid under control.:f_spider:

 

[spydsense]

doing donuts in the yard the nanny kicks in all the time... dang nanny

 

[NancysToy]

Actually it should trigger the VSS. Lets say the YAW sensor detects a skid to the left and the handlebars are turned to the right....the steering angle sensor and Yaw sensor would work together to detect this skid and apply individual brakes as needed to bring the skid under control.:f_spider:

This would take a heck of a skid! The yaw sensor detects a change in the side-to-side attitude of the machine (lean). It cannot detect a simple skid. That would take a separate lateral accelerometer. A simple skid on a straightaway would not raise one side of the Spyder readily. The steering angle sensor alone cannot differentiate between a turn and a correction. The second input would have to come from another sensor, either a differential in the speeds of the front wheels, or perhaps from the steering torque sensor, comparing the effort to the actual steering angle. To involve the yaw sensor, a skid to the left would require both the turn of the handlebars to the right, plus the skid to the left would have to be severe enough to start to tip the Spyder. Not sure how sophisticated the TCS part of the programming really is.

 

[spydsense]

ok actually its the VSS that kicks in....and the little light comes on

 

[NancysToy]

ok actually its the VSS that kicks in....and the little light comes on

The VSS has a couple of components. It consists the Traction Control System (TCS), which reduces the power to the rear wheel under certain circumstances, and the Stability Control system (SCS), which will try to maintain you steering line and keep you from tipping over in a turn. This one can individually control the brakes, reduce the engine timing, or cut back the throttle body, depending on needs. Both are considered VSS, and will light the indicator.

 

[spyryder]

This would take a heck of a skid! The yaw sensor detects a change in the side-to-side attitude of the machine (lean). It cannot detect a simple skid. That would take a separate lateral accelerometer. A simple skid on a straightaway would not raise one side of the Spyder readily. The steering angle sensor alone cannot differentiate between a turn and a correction. The second input would have to come from another sensor, either a differential in the speeds of the front wheels, or perhaps from the steering torque sensor, comparing the effort to the actual steering angle. To involve the yaw sensor, a skid to the left would require both the turn of the handlebars to the right, plus the skid to the left would have to be severe enough to start to tip the Spyder. Not sure how sophisticated the TCS part of the programming really is.

The YAW sensor IS a lateral accelerometer. If it senses a left turn when the bars (and SAS) are turned right then the two sensors would be in conflict with each other. The ABS/VSS module then takes this information and applies brakes individually to bring the vehicle under control.
Take a look at the VSS video where the box falls off the back of the truck and the Spyder maneuvers around it by automatically applying individual brakes without spinning out or losing control.

 

[NancysToy]

The YAW sensor IS a lateral accelerometer. If it senses a left turn when the bars (and SAS) are turned right then the two sensors would be in conflict with each other. The ABS/VSS module then takes this information and applies brakes individually to bring the vehicle under control.
Take a look at the VSS video where the box falls off the back of the truck and the Spyder maneuvers around it by automatically applying individual brakes without spinning out or losing control.

I understand how the yaw sensor works under these conditions, but it would be different in a traction control situation. The sideways slip would have to be severe, even if it were a pure lateral accelerometer, rather than an attitude sensor (think plumb bob). It really matters not. It's all a matter of degree. Bottom line is that the VSS does not kick in under mild, semi-controlled events, like minor fishtailing at lower speeds, but it does kick in when it is really needed, at speed or in turns. Sort of like magic, huh?

 

[spyryder]

I understand how the yaw sensor works under these conditions, but it would be different in a traction control situation. The sideways slip would have to be severe, even if it were a pure lateral accelerometer, rather than an attitude sensor (think plumb bob). It really matters not. It's all a matter of degree. Bottom line is that the VSS does not kick in under mild, semi-controlled events, like minor fishtailing at lower speeds, but it does kick in when it is really needed, at speed or in turns. Sort of like magic, huh?

Yes, for the traction control to activate all you really need to do is turn the handlebars more than 5 degrees off center while spinning the rear tire. So that would be the SAS and the wheel sensors coming into play. I believe that cuts out one cylinder on the RS. On the R/T it cuts back on the electronic throttle, which is much smoother.

 

[Mo Lee]

I guess my nanny works I took a quick right turn yesterday and the road was banked the wrong way the right tire hit some rough pavement and bounced enough to kick the nanny in.

 

[Lamonster]

Yes, for the traction control to activate all you really need to do is turn the handlebars more than 5 degrees off center while spinning the rear tire. So that would be the SAS and the wheel sensors coming into play. I believe that cuts out one cylinder on the RS. On the R/T it cuts back on the electronic throttle, which is much smoother.

If you listen to my motor in this video you can hear it cut out when I first take off and when I turn around and take off.
[ame]http://www.youtube.com/watch?v=yAUdFa1ayC4[/ame]

 

[mike3069]

The YAW sensor IS a lateral accelerometer. If it senses a left turn when the bars (and SAS) are turned right then the two sensors would be in conflict with each other. The ABS/VSS module then takes this information and applies brakes individually to bring the vehicle under control.
Take a look at the VSS video where the box falls off the back of the truck and the Spyder maneuvers around it by automatically applying individual brakes without spinning out or losing control.

I understand how the yaw sensor works under these conditions, but it would be different in a traction control situation. The sideways slip would have to be severe, even if it were a pure lateral accelerometer, rather than an attitude sensor (think plumb bob). It really matters not. It's all a matter of degree. Bottom line is that the VSS does not kick in under mild, semi-controlled events, like minor fishtailing at lower speeds, but it does kick in when it is really needed, at speed or in turns. Sort of like magic, huh?

It may be a lateral accelerometer, but it can be fooled IF the road banks to the inside in an uphill turn very easily (actually lifting the inside tire a foot or more) without triggering either wheel braking or engine cut-out.
This leads me to belive that it is really looking for LEAN ANGLE in relation to both vertical, and the SAS input.

The example you state in the video has a pretty large degree of body roll (lean angle compared to vertical) AND steering input. In a SLIDE this would not happen until you regained traction and created large side force (or rather, resistance to inertia generated by the slide).

 

[Lamonster]

You know whats funny, the last couple of days the roads have been wet and I've been able to do some pretty killer powerslides without the nanny kicking in. I did a real good one Sat. that really surprised me that it didn't kick in. I'm not sure if that has anything to do with my last update or not but it's pretty cool and makes me want to start on my Spyabusa project even more.