Talk:Tilting three-wheeler

A New Angle on creating lateral accelleration of a wheeled vehicle.

The accepted way to cotrol the steer angle of a wheeled vehicle is by some direct link between the driver input control and the steered wheel/s, but this is not necessarily the best arrangement for a narrow tilting vehicle. A new concept is under review which allows the steered wheels to be dynamically controlled by tilting them, along with the vehicle mass. This system is becoming known as Free to castor[FTC]. The directional control of a FTC wheel is not particularly strong as exampled by a shopping trolley, and the castor will turn due to any applied side loading. However if the castor is tilted its directional stability above about 10mph is very strongly controlled by the dynamic forces and if the castoring element is attached to the front of a narrow tilting vehicle the castor will automatically place itself on the correct steer angle for the tilt and the speed of the vehicle. This knowledge is revealed in Patent WO2005/075278 and there is gathering acceptance of the viability of this system as a practical way to create a narrow simple steer tilting vehicle


 * The above paragraph is written by "Phillip" from http://www.tiltingvehicle.net/ind.html, which makes it very partial. The comment claims, for instance "...there is gathering acceptance of the viability of this system...". Gathering acceptance by whom? If I may ask. I respect the work of any individual, but this assertion violates the principles of Wikipedia, namely the original work and the lack of references. Martinmdp (talk) 19:01, 29 October 2009 (UTC).
 * Phillip here. Since this comment a link has been included in the Article [see front page]. The link takes readers to a research paper by the University of Tokyo describing Free to Castor vehicle systems. - Cambering (talk) 00:18, 26 December 2019 (UTC)

Attributes of active and passive tilting
Hi Andrew you said;
 * "active-tilt vehicles may possess roll stability similar to rigid tricycles, and if traction is lost, the vehicle may be no more likely fall than a rigid tricycle, depending on how the active tilting is implemented"

My point would be that an active tilt tricycle does possess roll stability not "may possess" as you put it. Furthermore what "implementation' do you suggest allows the use of you statement:
 * "may be no more likely fall than a rigid tricycle, depending on how the active tilting is implemented"

What is needed from you here is an example of how 'implementation" allows loss of traction to cause an active tilt vehicle to fall. This then leads to a need to define "fall" and "trip" https://tiltingvehicle.blogspot.com/2014/06/tilting-vehicle-news.html This then leads to the need to debunk the myth that traction depends on the number of wheels. https://tiltingvehicle.blogspot.com/2012/10/traction-patch-area-as-it-relates-to.html I am all for expanding the technical understanding of the wikepedia article. Lets do this. Comments please - Cambering (talk) 00:08, 15 December 2019 (UTC)


 * My points are:
 * Passive tilt vehicles may exhibit roll stability, just as motorcycles and bicycles can under the right conditions, and to avoid getting into what all those conditions might be, I simply state that the two types of vehicles will have similar roll stability.
 * Active tilt vehicles may exhibit roll instability, just as automobiles and rigid tricycles can under the right conditions, and to avoid getting into what all those conditions might be, I simply state that the two types of vehicles will have similar roll stability.
 * To make any stronger claim is to overstate the case.
 * For the word "fall" I was thinking of the vehicle ending up not on its wheels and not about the distinction between highsides and lowsides. No I cannot think of an active tilting implementation that would cause a lowside due to loss of friction. Highsides, on the other hand, are easy. -AndrewDressel (talk) 01:10, 15 December 2019 (UTC)


 * Hello Andrew. First to your last sentence you said; "no I cannot think of an active tilting implementation that would cause a lowside due to loss of friction. Highsides, on the other hand, are easy." I assume that what you are saying here is that when traction returns ... and the sliding active tilted vehicle experiences a re-grip the inertia of the sliding mass can capsize the vehicle. Of course this can occur, however my original statement was that an active tilter cannot "fall". A motorcar or an active tilter can capsize over its outer wheels but it can't "fall" as a passive tilter can.


 * For example a CARVER in a slide regrip would not capsize and many other active tilters actually possess more roll stability than a car at the same lateral acceleration and so would resist a capsize during a slide re-grip better than a wide conventional car. So to claim [as you did] that "highsides are easy" misses the mark. You have not differentiated between a fall and a capsize. If it is desirable to do this then lets do so.


 * Now to an earlier statement You said "passive tilt vehicles may exhibit roll stability" I agree that there is a wide misunderstanding on this point which should be clarified. I would say there is "dynamic stability in a passive tilter as long as there is traction available to the steerable wheels." It is well agreed that the stability exhibited by motorcycles and other passive tilting vehicles comes from the reaction between the front wheel(s) and the road surface. If this traction is removed the vehicles "exhibited roll stability" as you expressed it, will disappear. In an active tilting system the stability (however expressed) will not diminish.


 * So, something needs to change in the way we express "stability", and I suggest that passive systems exhibit dynamic stability with traction whereas active systems exhibit roll stability at all times regardless of traction. - Cambering (talk) 01:57, 15 December 2019 (UTC)


 * Let us use the terms "highside" and "lowside", which are already defined and documented in articles here on Wikipedia, instead of other terms, which might be well-defined elsewhere, but need further clarification here.
 * The fact that some "other active tilters actually possess more roll stability than a car at the same lateral acceleration" does not apply to all active tilters and so cannot be asserted without qualification.
 * Traction may be "reduced" but not "removed" and so roll stability may be "reduced" but not "removed". I regularly have the opportunity to ride my bicycle on glare ice without studded tires. It can be tricky, but not impossible.
 * Given that active tilt systems may be implemented in a myriad of ways, with different sensors, actuators, controllers, and even kinematic limits, I cannot see how we can make any blanket claims about their performance. - AndrewDressel (talk) 14:27, 15 December 2019 (UTC)


 * You have continued to state that passive tilters have "roll stability". A passive tilter is a virtual STV. If a STV had "roll stability" it could not develop "self stability". This is because to develop self stability the STV/ passive tilter must be free to roll. The freedom to roll is what allows the castoring front wheel to steer in the direction of the roll so to develop centrifugal force acting on the vehicle mass to counter the roll and return the vehicle to vertical. This "back and forth" motion is generally not detectable by the rider. - Cambering (talk) 19:38, 15 December 2019 (UTC)


 * By "STV", I suppose you mean single-track vehicle, right? Since "self stability" is about the "roll" axis, I do not understand your distinction between "roll stability" and "self stability". Lastly, what "back and forth" motion do you mean? - AndrewDressel (talk) 20:19, 15 December 2019 (UTC)


 * Also of course, if the rider locks / positions the front wheel any roll of the STV/VSTV will not produce a steer of its front wheel to counter the roll and the vehicle will simply fall down. And so the first step seems to be to drop the use of "roll stability" as a term that applies to virtual STV vehicles and replace the use of the term with "self stability". I maintain that it is valid to say that active tilters have roll stability. The stability that an active tilter possesses is different to the stability that a passive tilter exhibits. An active tilter possesses roll stability. That's the only blanket claim that I originally made however, the consequence of the claim is that active tilters do not fall down on ice [can not fall down] whereas a passive tilter can fall down on ice (your experience on ice demonstrates it CAN fall down). - Cambering (talk) 19:38, 15 December 2019 (UTC)


 * Ah, now I see your distinction, but since "self stability" and "roll stability" are both about the roll axis, they seem like poor choices to distinguish between stability inherent in an uncontrolled mechanism and stability generated by an active controller with sensors and actuators. We're talking about behavior along only one axis here, uncontrolled <=> controlled, right? "Self stability" is pretty well established in the bike literature, so we're probably stuck with that. Perhaps "closed-loop stability" or even "imposed stability" would work. All active tilters have feedback loops, right? - AndrewDressel (talk) 20:19, 15 December 2019 (UTC)


 * Also, to confuse the issue by introducing reflections on passive tilters with spring loadings to the vertical is not helpful and all reports that I have read say that these systems have never been successful and so should not be relied upon in the article. - Cambering (talk) 19:38, 15 December 2019 (UTC)


 * If we can find a reliable source that asserts that open-loop controllers cannot be successful on tilting tricycles, we should definitely include that detail. Short of that, however, I see no reason to exclude them from the discussion. -AndrewDressel (talk) 20:19, 15 December 2019 (UTC)


 * I am sure we agree that there is confusion. A few further points about active tilters: In some sense you could say that active tilters are "deformable cars". A motor car definitely has roll stability and it is created directly by the lateral spacing of its wheel sets. It will not "fall down" when traction is removed, it will simply slide across the surface. An active tilter has the same physical properties as the motorcar. The advantage being that the active tilter moves it c of g inwards in a corner whereas a motorcar tries to roll outwards. The advantage of the active tilter is that it increases stability as it turns whereas a motorcar loses stability as it turns. This allows an active tilter to be narrower than a motorcar [or a rigid tricycle] The overriding point here is that an active tilter uses its laterally spaced wheel set to create "roll stability" at all times whereas a passive tilter does NOT use its laterally spaced wheel set to create roll stability [except when the wheel set is locked when slowing down]. - Cambering (talk) 21:28, 15 December 2019 (UTC)
 * It might be helpful for both of us if you took a look at my publications so that you can stop wasting both our time by lecturing me about vehicle dynamics. You can find a list on my UWM page. I'd look up your bio, but you appear to be a man of mystery. Even your own blog says nothing about you. - AndrewDressel (talk) 04:00, 16 December 2019 (UTC)
 * So, the challenge is to use words in the article that makes the facts absolutely clear to readers who may not have a good basic understanding. - Cambering (talk) 21:28, 15 December 2019 (UTC)
 * I agree. -AndrewDressel (talk) 04:00, 16 December 2019 (UTC)
 * To this end, the Article should be largely expanded. What we seem to be doing is debating "terms" while ignoring the large picture. Not sure that moving into the subject of "feedback loops" is going to help. The passive tilter [VSTV] is riddled with feedback loops... but the active tilter need not be. All that is required is that the driver moves his control and this motion is reflected in a tilting action. This further illustrates the difference between passive and active tilters. The active tilter is steered exactly like a motorcar whereas a passive tilter is steered exactly like a STV. The active tilter driver does NOT countersteer the control, he displaces the control in the direction he wants to go. However, it is common for an active tilter to Automatically countersteer independent of the simple steer input of its driver. - Cambering (talk) 21:28, 15 December 2019 (UTC)
 * Sure, there is plenty that can be added to the article, but there is nothing to debate if we don't have a common language. For example, we appear to have completely different understandings of the expression "feedback loop". - AndrewDressel (talk) 04:00, 16 December 2019 (UTC)


 * Hi, the feedback article describes "feedback loops" pretty well as they apply in machines and other things. However I don't think the subject needs to be talked about in this Article. I think a lot of progress has been made. - Cambering (talk) 06:27, 17 December 2019 (UTC)
 * Great, but perhaps we can still sort out
 * "The passive tilter [VSTV] is riddled with feedback loops... but the active tilter need not be."
 * By "VSTV" do you mean "virtual single-track vehicle"? What are some of the feedback loops it is riddled with? - AndrewDressel (talk) 13:12, 17 December 2019 (UTC)

Of course "VSTV" means "Virtual Single Track Vehicle". Where have you been? - Cambering (talk) 09:56, 18 December 2019 (UTC)


 * Ouch! No need to get snarky. I searched your blog and could not find it spelled out explicitly, asking on google is no help, so I asked here to make sure.

Its a common expression by those in this field. It simply means that although 3 wheel free leaners are NOT a single track vehicle because of laterally spaced wheels, if the tilting mechanism is  free[unlocked]  the vehicle is a VIRTUAL  STV. It also is a good expression and it is also easy to grasp. [ its not my expression, its been used for decades.]Cambering (talk) 22:33, 18 December 2019 (UTC)

As for "where I've been", my bio is pretty easy to find online. My wikipedia profile has some details and links to other sites with the rest. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

I am not big on " bios "so what"Cambering (talk) 22:33, 18 December 2019 (UTC)

The feedback loop that urges the vehicle to the vertical hands free (what you insist on calling "roll stability"). This is composed of multiple loops 1] tyre/road slip angle 2] steer/tilt couple, which occurs on both sides of vertical to urge the vehicle to vertical. Driver applied Countersteer to alter the tyre road servo and force the vehicle to lean. Relaxation of driver countersteer torque to allow the vehicle to settle into a new steady state. All of these things are servo mechanisms with [hopefully] stable feedback. An example of an unstable feedback servo loop is a "tank slapper" - Cambering (talk) 09:56, 18 December 2019 (UTC)


 * Ah. Many of your examples are not feedback loops in the conventional, engineering sense. From the feedback article:

I disagree.Cambering (talk) 22:33, 18 December 2019 (UTC)


 * Over the years there has been some dispute as to the best definition of feedback. According to Ashby (1956), mathematicians and theorists interested in the principles of feedback mechanisms prefer the definition of circularity of action, which keeps the theory simple and consistent. For those with more practical aims, feedback should be a deliberate effect via some more tangible connection.


 * [Practical experimenters] object to the mathematician's definition, pointing out that this would force them to say that feedback was present in the ordinary pendulum ... between its position and its momentum—a "feedback" that, from the practical point of view, is somewhat mystical. To this the mathematician retorts that if feedback is to be considered present only when there is an actual wire or nerve to represent it, then the theory becomes chaotic and riddled with irrelevancies.[10](p54)


 * I'm thinking more along the lines of a deliberate effect via some more tangible connection. - AndrewDressel (talk) 15:14, 18 December 2019 (UTC)

How can an active tilter control tilt angle without a feedback loop? Since the rider on a FTC active tilter cannot control steer angle directly, he must compare the current path to the desired path and adjust the tilt angle accordingly, no? - AndrewDressel (talk) 13:12, 17 December 2019 (UTC)


 * Not well put. A driver of a FTC does NOT observe the tilt angle. He observes the steered path of the vehicle and steers the control to adjust the path exactly the same as a car driver does. While it is true that his steering wheel does indeed tilt the vehicle, the steer of the wheels are so tightly bound to the tilt of the vehicle that the driver has no regard for tilt angle at all. His only focus is the steered path created by the wheels and his observation becomes that the WHEELS are directly connected to his control. On the other hand a free tilter rider [VSTV] is obsessed with tilt angle. He knows that if he does the wrong thing on the bars he can fall. The driver of FTC knows he can't fall and so has no direct regard for the tilt angle because it will always be correct for any speed or corner he steers at.
 * The same basic principle applies to all active tilters. The advantage of FTC is that there are no complex electronic computations. The castoring wheel/s are the computer.
 * Also in the CARVER there are no computations. It is a very simple and clever hydro mechanical control system. I am not going to fully describe how all tilting vehicles work. - Cambering (talk) 09:56, 18 December 2019 (UTC)


 * I never wrote nor suggested that the FTC rider observes the tilt angle. Instead, I explicitly state he observes the steered path of the vehicle. Meanwhile, the rider of a free tilter has about the same concern with tilt angle as the rider of a bicycle or motorcycle. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

Exactly the same I suggest... because?... a free leaner IS a VSTV.Cambering (talk) 22:33, 18 December 2019 (UTC)

If the active tilter is not FTC, then some entity must compare the current tilt angle to the desired tilt angle and adjust the title angle accordingly, right? Either way, it appears that a feedback loop is necessary. - AndrewDressel (talk) 13:12, 17 December 2019 (UTC)


 * What you say roughly describes the Toyota I Road. What matters is the reliability and effectiveness of the servo systems used to control active tilters AND the reliability of the humans capacity to manage a free tilters servo systems [ VSTV].
 * Yes there are feedback loops everywhere, but what I said originally was: "The passive tilter [VSTV] is riddled with feedback loops... but the active tilter need not be." Obviously it depends on the individual designs as to "how riddled" they are. - Cambering (talk) 09:56, 18 December 2019 (UTC)
 * And now to the latest alterations that have appeared. Comments inserted. - Cambering (talk) 10:42, 18 December 2019 (UTC)

active, passive, and free usually refer to how the tilt angle is controlled, if at all.
 * Are we talking about tilting vehicle control... hopefully the tilt angle IS controlled? - Cambering (talk) 10:42, 18 December 2019 (UTC)
 * Yes, it should probably say something more along the lines of "active, passive, and free usually refer to how the tilt angle is controlled: directly or indirectly." I've made the change. - AndrewDressel

But how on earth did it get put that way in the first place?Cambering (talk) 22:33, 18 December 2019 (UTC)

(talk) 14:28, 18 December 2019 (UTC)
 * And, to be perfectly clear, I am using the terms "active" and "passive" as they are also used in vibration control,

yes I know what you are doing   but its not helpful  to the average reader! Cambering (talk) 22:33, 18 December 2019 (UTC) noise control, vehicle suspension, etc.:

Yes, Yes...but I remain unimpressed [ sorry]Cambering (talk) 22:33, 18 December 2019 (UTC)
 * "Active ... control is the active application of force ..."
 * "In the past, passive techniques were used. These include traditional vibration dampers, shock absorbers," etc.

All this does is confuse others. I am not confused, I understand technical use of the terms but...Cambering (talk) 22:33, 18 December 2019 (UTC)


 * At the same time, I believe we can distinguish direct tilt control from indirect tilt control.


 * Your FTC provides direct tilt control to the rider, which then indirectly controls steering. Sure, the coupling may be tight, and the rider might think he is controlling steer angle, but there is no explicit mechanism to generate torque about the steer axis. You call it "free to caster" after all.

not true. A FTC vehicle is free to castor but its not free to do anything else. It must follow. The mechanism is the castoring and tilting wheel attached to the tiltable vehicle section. When the University of Tokyo plagiarized my 2005 prior art, they called the wheel " free to rotate" [ about the steer axis] I pointed out that its not Free to rotate[ about he steer axis] it is only free to CASTOR. In other words it is constrained to one steer angle said steer angle  depending on the speed of the vehicle and the tilt angle of the vehicle. The Moon is not " free to orbit" about the Earth it is forced into its orbit.Cambering (talk) 22:33, 18 December 2019 (UTC)
 * Our trike, on the other hand,\

To readers: here Andrew is talking about the thing he cant talk about in the Article. I don't agree with he rules by the way. But we seem stuck with them In many ways  the wiki rules against self promotion are forcing  Andrew  into abstract vehicle classifications  that will fit his experimental vehicle.[ one day]  I don't believe his vehicle needs a new classification [ passive tilter]  I suffered the same fate with my early attempts to include FTC,  I had to wait 14 years until the University of Tokyo Plagiarized my work in a technical paper  thus creating an acceptable link Cambering (talk) 22:33, 18 December 2019 (UTC)

provides direct steer control to the rider, which then indirectly controls tilting. its called " manual countersteer control"  This term was needed when " automatic countersteer was developed. Its sufficient to say its a " free leaner"Cambering (talk) 22:33, 18 December 2019 (UTC)

Sure, the coupling may be tight, but there is no explicit mechanism to generate roll torque.

Absolutely not true. The coupling of the steerable wheel to the road surface [with traction] allows a servomechanism which is just another form of a roll actuator. The rider controls the servo mechanism to effect roll motion. The power to operate the roll actuator mechanism is INERTIA![ when in motion]Cambering (talk) 22:33, 18 December 2019 (UTC)

In addition, our trike also happens to provide some passive control over tilt rate, in the sense described immediately above, and thus indirectly tilt angle, but I believe that is independent of the point I am trying to make here. Sure ,but what about the poor readers?Cambering (talk) 22:33, 18 December 2019 (UTC)
 * I'll work on adding this clarification to the article as well. -AndrewDressel (talk) 17:37, 18 December 2019 (UTC)

Do we have to?Cambering (talk) 22:33, 18 December 2019 (UTC)

"Active" control usually requires some sensor(s), some capacity to make decisions,
 * "make decisions"? - Cambering (talk) 10:42, 18 December 2019 (UTC)
 * Yes, it should probably say something more along the lines of "calculate a response." I've made the change. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

Yes, but how did the expression [ make decisions] ever get into your head in the first place. That's what worries meCambering (talk) 22:33, 18 December 2019 (UTC)

such as a feedback controller,
 * who is this? - Cambering (talk) 10:42, 18 December 2019 (UTC)
 * The rider or some other active controller. Some entity that can calculate a response to a sensed state. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

and some actuator(s) that require power sources.
 * Like a power steer car for example? - Cambering (talk) 10:42, 18 December 2019 (UTC)


 * Yes, I suppose power steering on a car is a fine example of a powered actuator. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)\

well...that's EXACTLY what I use in my FTC vehicles. I remove the power steer servo valve from the  steering rack. I cut the actuators out of the rack and put them in the tilting mechanism. I put the PS valve in a feedback connection between the drivers control and the tilting mechanism. So now the technology is rearranged. The CARVER uses the same type of servo valve but they arrange their vehicle  differently.[ do research on the CARVER in the patents]

A driver steering an automobile exhibits active control by sensing the direction of the vehicle visually, comparing this direction against the desired direction, and making corrections by rotating the steering wheel


 * Why are we discussing motorcars? You could use the exact sentence and replace "Motorcars" with "active tilters". - Cambering (talk) 10:42, 18 December 2019 (UTC)


 * Because I am trying to use a more-accessible and commonly-experienced example for readers without experience with "active tilters". - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

Phillip here in absolute desperation[ almost]. Anyone...everyone who has any interest in the subject should know that active tilters are steered exactly the same as  a motorcar. This is [ one]of the motivational reasons why active tilters were developed. They allow people with common motorcar skills to just hop in and  drive off.Cambering (talk) 22:33, 18 December 2019 (UTC)

with arms and hands powered by muscles fueled with glycogen.
 * What on earth does this contribute to the Article? - Cambering (talk) 10:42, 18 December 2019 (UTC)
 * Spell things out so that readers are not left to wonder. Who knows where they've been. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

or else just to give them a [ false] impression of how clever you are? Theres nothing wrong with what you said its just an unnecessary embellishment of the obvious. The poor sods reading want the plain truth. The plain truth is tricky enough in this field as it is.Cambering (talk) 22:33, 18 December 2019 (UTC)

"Passive" control is the opposite of this: there are no sensors, comparisons, decisions, or actuators.
 * Rubbish. [I assume you are talking about control of tilters?] The sensors are in the riders head and the comparisons are human, the decisions are human and the actuator is the servo power created by the the tyre on the road when countersteering which causes the vehicle to tilt and ... when traction goes so does the "actuator". - Cambering (talk) 10:42, 18 December 2019 (UTC)


 * That is not at all how Ruina's or our passive control works. In Ruina's, the tilt angle is passively controlled by springs. It works with or without a rider. In ours, the tilt angle and rate is passively altered by gravity through the variable tilt linkage geometry. It also work with or without a rider. Neither of our passive control implementations require traction to keep the vehicle upright when they are configured to do so. In both cases, the rider is left to contend with a vehicle that is no longer completely free tilting. In Ruina's case, he claims that riders find the resulting, neutrally-stable, vehicle effectively uncontrollable, and you contest that claim.

NOT true. I said to Ruina that the vehicle could not be controlled on Earth in Gravity because the vehicle had been converted to behave as if was in  zero gravity BUT the riders knew that they were not. Conflicting feedback! see https://tiltingvehicle.blogspot.com/2014/03/bricycle-cornell-university-got-it-wrong.htmlCambering (talk) 22:33, 18 December 2019 (UTC)

In our case, the riders find the resulting vehicle easier to control.

Easier to control compared to what? The original Tolhurst recumbent? Sure thing but only when trying to get on board the recumbent riding position and getting up to speed. We understand the original difficulty and your improvement to it but, your vehicle remains a free leaner. All free leaner riders is constantly modifying the roll rate of his vehicle.. feet on the ground at slow speed/stopped, a prod of one foot to the ground to correct a developing fall, a dirt track  rider  with inner foot planted, a GP  rider with knee pad on the track etc etc.  BUT they are all "free leaners"  We don't create a separate vehicle classification.Cambering (talk) 22:33, 18 December 2019 (UTC)

An aggressively recumbent trike with moving bottom bracket that students struggled mightily to learning how to ride, spending hours practicing before the competition, becomes docile and easy to learn, requiring only minutes to feel comfortable. Henry Thomas at jetrike.com also experienced and documented this. He just appears never to have implemented rider control of the linkage geometry, opting to pick his single favorite behavior instead. I'm sure there are plenty of others.

Look, you have a system that at stopped holds the vehicle lightly to the vertical. This allows the rider to get into the seat. Its just as easy to do this with a full tilt lock arrangement. Then you move off and release your mechanism and the vehicle becomes a free leaner. You also have the ability to set the roll motion to various values. What I say, is that if you alter the roll characteristics this alters the feedback to the rider [ feedback again]...and this  potentially confuses the rider because he does not know what to expect. If you leave the roll adjustment that you have in place at 1 mph and then  speed up to 15mph you are going to get a nasty surprise.Cambering (talk) 22:33, 18 December 2019 (UTC)


 * I'm not trying to insert all this into the article because I don't have good, published sources besides Ruina's and mine. I'm just using the details here to address your point and explain my understanding of passive tilt control. If you can cite some other source with some other definition, I'd love to see it. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

Passive tilt is a confusing expression, I have seen it used to describe " free leaners". As I said above, free leaners s all we need.Cambering (talk) 22:33, 18 December 2019 (UTC)

The suspensions of many automobiles, consisting only of inanimate springs and dampers, demonstrate passive control.
 * Back to motorcars again? This is a discussion about control of tilting vehicles not about suspension characteristics. - Cambering (talk) 10:48, 18 December 2019 (UTC)
 * And again, when describing something new, it can be helpful to make analogies to something familiar. - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)

Well, the passive suspension characteristics of a motorcar don't have anything to do with the passive [ tilt suspension] of a tilter. The motorcar rolls outwards on its springs because it cant countersteer into a tilted position... because its suspension stops this... unless the driver launches with a ramp up onto two wheels and this converts the car to a ' free leaner". I now see a new ' vehicle classification"  coming into view!Cambering (talk) 22:33, 18 December 2019 (UTC)

"Free" usually means that the vehicle is as free to tilt as a bicycle or motorcycle.
 * Phillip here, lets get rid of this. - Cambering (talk) 10:42, 18 December 2019 (UTC)
 * Get rid of what? The description of free tilting? The distinction between free, passive, and active tilting control? - AndrewDressel (talk) 14:28, 18 December 2019 (UTC)


 * I give up. - AndrewDressel (talk) 02:30, 19 December 2019 (UTC)

Phillip here, just made significant edits to remedy  Andrew Dressel. Andrew believes that " free tilters" and " passive tilters" are different. They are not. The two terms are directly interchangeable. Direct email conversations are taking place in an attempt to sort this out. My editing can be improved but I suggest  collaboration should occur here before we go back to the mess caused by Dressell - Cambering (talk) 00:38, 21 December 2019 (UTC)


 * LOL. You could at least spell my name correctly, BOTH TIMES, when you complain about me. It appears the same way every time I sign my name! I've already spent literally hours editing your ham-fisted additions to make them legible. The least you could do is spell my name correctly. There is only one "L"! Who the heck do you think is reading this? "To Readers" ha ha ha. There are no readers. No one edits Wikipedia anymore. They are all posting on instagram now, or whatever kids are up to these days! It is just you and me here. Two old farts bickering about nothing that maters, like two bald guys fighting over a comb, to quote Dr Evil. Wanna make this article better? Quit pissing in my cereal! Don't like my sources? Find better ones! "Direct email conversations" are not taking place. - AndrewDressel (talk) 03:09, 21 December 2019 (UTC)

Dear Readers. Andrew thinks you don't exist !. This is probably why he runs his own "fake news agenda" on the article page. I am not going to get involved in an Edit War on the front page. Andrew has clearly indicated he has no intention of any further engagement. Please read the following [ but only if you exist] https://researchportal.bath.ac.uk/files/187920492/Active_Control_of_Narrow_Tilting_Vehicle_Dynamics.pdf 'Active Control of Narrow Tilting Vehicle Dynamics James William Robertson A thesis submitted for the degree of Doctor of Philosophy Department of Mechanical Engineering University of Bath February 2014

"Passive Tilt Control describes vehicles in which the driver is solely responsible for maintaining the stability of the vehicle through steering inputs and shifts in body weight. This is the system employed by motorcycles and bicycles. It requires considerable skill from the operator, and an additional means of stabilisation at very low speeds or when stationary'

Phillip here, so "passive" tilt control is exactly the same as ' free' tilt control and:

Urban and Extra Urban Vehicles: Re-Thinking the Vehicle Design Andrea Festini1, Andrea Tonoli2 and Enrico Zenerino1 1Mechatronics Laboratory - Politecnico di Torino 2Mechanics Department, Mechatronics Laboratory - Politecnico di Torino Italy https://www.intechopen.com/books/new-trends-and-developments-in-automotive-system-engineering/urban-and-extra-urban-vehicles-re-thinking-the-vehicle-design "Two types of strategies were pursued for tilting: passive and active tilting. In the passive tilting mode no tilting actuator is present. The tilting lever is free to rotate about its hinge axis. The tilting degree of freedom is therefore free. The driver controls the roll angle by acting on the steering system, this is the same as in the case of a motorbike. A mechanical brake allows stable stopping. This configuration has been mainly used for testing and vehicle dynamics model validation. In the active tilting mode the angle between the tilting crank and the frame is controlled by an electromechanical actuator. In this case the driver acts on the steer as on a car and an active control system imposes the vehicle roll angle during bends." and For the front axle two tilting suspension strategies were considered: passive (free) and active tilting. In the first case, to allow the leaning of the vehicle, a free tilting suspension provides the roll degree of freedom, as in a two wheels bike. The driver then controls the roll angle by acting on the steering system. In active tilting, the vehicle roll is controlled by connecting an actuator to the suspension. The active control system sets the vehicle roll angle basing its commands on sensors and a suitable control strategy.Cambering (talk) 04:07, 21 December 2019 (UTC)

Terminology
There is now agreement that free tilters and passive tilters are the same thing and in other sections of the main Article the expression" free/passive" is now being used. However, the reference in this section to 'passive' control of motorcar roll control[ suspension components] confuses the clarity of the rest of the article and is unnecessary. The term "passive" means different things in different disciplines. Also, the statements about how a motorcar driver controls a car " active control' is also not helpful here because 'active control' means a different thing in this discipline. It is already stated that "active control" of tilters means control of the tilt angle. In other words, although the terms "free tilter" and "passive tilter' have been combined into the expression "free/passive tilter" in the other sections of the main Article, confusion remains in this section. This is understandable because when this section was written the Author did not understand that 'free' tilters and 'passive' tilters were the same thing. I invite others to comment on how to improve this section. - Cambering (talk) 00:24, 28 December 2019 (UTC)


 * There is no such agreement. - AndrewDressel (talk) 01:15, 28 December 2019 (UTC)


 * Phillip here Andrew "no such agreement"? In the Article it says; "Free tilting and passive tilting vehicles are controlled as with a bicycle or motorcycle, in which case countersteering is required.[12] Actively controlled tilters are where the rider or some other controller actively sets the tilt angle directly." I have earlier provided links where it is made clear that "free" and "passive" are terms that are directly interchangeable. What are you trying to say now? - Cambering (talk) 06:14, 28 December 2019 (UTC)


 * None of the sources included so far explicitly assert that "free tilters and passive tilters are the same thing". Simply because some authors, for whom English is not their first language, appear not to distinguish between "free" and "passive" does not mean that they are "the same thing". They certainly are not the same thing generally in engineering. See sound and vibration control. With the current references, the best we can assert is that "some authors appear to equate 'free' and 'passive'" or "some authors appear to use 'free' and 'passive' interchangeably".
 * This phenomenon is common on Wikipedia. The terms longitudinal engine and transverse engine are used differently by different manufacturers. "Rake" is used to mean different measurements on motorcycles and bicycles. The best an article can do is explain the different usages. - AndrewDressel (talk) 15:58, 28 December 2019 (UTC)


 * Phillip here, I quote again from 'Active Control of Narrow Tilting Vehicle Dynamics James William Robertson A thesis submitted for the degree of Doctor of Philosophy Department of Mechanical Engineering University of Bath February 2014. Quote: "Passive Tilt Control describes vehicles in which the driver is solely responsible for maintaining the stability of the vehicle through steering inputs and shifts in body weight. This is the system employed by motorcycles and bicycles. It requires considerable skill from the operator, and an additional means of stabilisation at very low speeds or when stationary' end of quote.
 * The people at Bath University are English Speaking and have a long history of experimental research in this field. On the other hand you choose to quote from a different field of engineering being "vibration control". The Article we are attempting to edit is not about "vibration control", it's about tilting vehicles. - Cambering (talk) 21:13, 28 December 2019 (UTC)


 * This paper is not by "the people at Bath", it is by one graduate student at Bath. The paper is not about tilting three-wheelers in general, it is about "the implementation of a Steering Direct Tilt Control (SDTC) system," and mentions passive tilt control in passing without citing any sources. It simply ignores the distinction between existing vehicles that are completely free to tilt and existing vehicles that control tilting with passive elements to improve the rider experience. - AndrewDressel (talk) 20:57, 29 December 2019 (UTC)


 * In the opening paragraph of this section I said "The term "passive" means different things in different disciplines", there is no disagreement on this point. I have demonstrated that Authors in the discipline of TTW vehicles use "free" and "passive" to describe the same thing. This use in and of itself establishes the terms "free" and "passive" as interchangeable. Your argument that I am using quotes from Authors "for whom English is not their first language" has been debunked and should not be repeated. However, why get bogged down in petty debate? My objection is your use of terms from non TTW disciplines. You continue to import terms from disciplines outside the scope of this Article to prop up your arguments and this is disruptive to the purpose of Wikipedia. -Cambering (talk) 23:32, 28 December 2019 (UTC)


 * You have merely shown that some authors are not very precise in their use of the terms "free" and "passive", just as is the case with "stable" and "stability". - AndrewDressel (talk) 20:57, 29 December 2019 (UTC)


 * Hi Andrew, what you say is true. And,there are additional alternate terms in use. Others use STC [ steer/tilt/control] and for Active tilt they use DTC [ direct/ tilt/control]. The problem  certainly exists and it makes it very difficult for casual readers of Wikepedia.Cambering (talk) 04:40, 30 December 2019 (UTC)
 * Andrew said "This paper is not by "the people at Bath", it is by one graduate student at Bath"  Phillip here, the student is not  alone see:

SYSTEM DEVELOPMENT FOR HYDRAULIC TILT ACTUATION OF A TILTING NARROW VEHICLE Benjamin Drew, Kevin Edge, Matt Barker, Jos Darling & Geraint Owen Centre of Power Transmission and Motion Control University of Bath quote "There are two methods of controlling the tilting action of the vehicle: passive and active. Passive tilt control necessitates driver skill, motorcycle controls and countersteering" end of quote. They could have equally used the term "free" instead of "passive". Its easy to imagine why " passive" is used to contrast  that term with " active" if you are developing an active tilter [the CLEVER in this case]The use of "free" or "passive"  is optional and was well established as optional long before they wrote their paper.Cambering (talk) 13:15, 30 December 2019 (UTC)

Countering gravity with roll modifications
Some experiments have been performed where Free/ passive tilters have their roll characteristics modified [see Ruina links]. There is a point where the gravity component acting about the roll axis can be countered by spring loadings so that the vehicle and rider will remain stable at any roll angle. There is debate as to how or if these vehicles could be controlled. That's not established as yet. However if an active tilter was so treated it would be a simple matter to tilt the vehicle to any angle regardless of any spring loadings applied to it. This is because active tilters have tilt actuators and are not controlled using countersteer. - Cambering (talk) 12:38, 8 January 2020 (UTC) Andrew had said during his revision of the Article: "How would a "free" tilting system counter gravity? Only "passive" and "active" have the ability and so they are correct." I have created this new topic to sort this out here to avoid edit wars on the main page. - Cambering (talk) 12:48, 8 January 2020 (UTC)


 * Ach du lieber.
 * 1. How can "stable" mean "return to upright" in the article if you use it here as "remain stable at any roll angle"?
 * 2. If it remains "stable" at any roll angle, how can it be "free"? That sounds like the exact opposite of "free".
 * 3. How can we be sorting it out here if you continue to insert the nonsensical "free" into the article?
 * I'm beginning to think it is a mistake to use "active", "passive", and "free" in the article at all. They are so poorly defined in the literature. I suspect "direct" and "indirect" are sufficient and better. - AndrewDressel (talk) 22:19, 8 January 2020 (UTC)


 * Hi Andrew, fair points. However the Ruina Bricycle is a 'free/passive tilter' that has been modified to test a theory. What we "call it "as modified" is up for discussion/ debate. "Free tilters" and "passive tilters" are existing terms accepted as interchangeable in the literature. I don't agree that the terms [Free/passive] and [Active] are poorly defined. We can't rewrite history. We need to come up with new terms if something new turns up. Ruinas Bricycle possibly should not be included in the article? - Cambering (talk) 23:19, 8 January 2020 (UTC) You also failed to address my point that Active tilters can overcome any spring loadings as described by Ruina. So, you have reverted to a false statement in the Article that should be returned to my versionCambering (talk) 23:27, 8 January 2020 (UTC)


 * The Ruina Bricycle is one of many tilting trikes, including Jetrike, PantherTrike, Aileron, etc., that is controlled with passive elements, thereby being a passively controlled tilter. Just because some authors, who are focusing on other things, use some terms sloppily does not mean that those terms are interchangeable. I cannot think of a reason to exclude Ruina's Bricycle from the article, and I simply cannot understand what you wrote about active tilters. - AndrewDressel (talk) 01:12, 9 January 2020 (UTC)
 * Phillip here, How simple can it be put before you understand?  Active tilters have actuators to alter the tilt angle. If Ruina put springs in the tilting mechanism of an active  tilter the actuators would simply dominate any effect the springs might  exert.  This is why any reference to " springs"  should not occur with reference to "Active tilters"Cambering (talk) 06:12, 9 January 2020 (UTC)
 * Phillip here, for the many readers who may not be aware of the RUINA experiments and my counter arguments go to: https://tiltingvehicle.blogspot.com/2014/03/bricycle-cornell-university-got-it-wrong.html
 * This ongoing debate has absolutely nothing to do with the validity of the existing terms "Free/ passive tilter" in the TTW article front page. - Cambering (talk) 00:59, 9 January 2020 (UTC)


 * Whether Ruina is ultimately right or wrong about the controllability of his trike has nothing to do with whether his trike is free to tilt or controlled by passive element, i.e. springs. - AndrewDressel (talk) 01:12, 9 January 2020 (UTC)

Phillip here. Either way his vehicle is not " controlled by passive elements" as you put it. It is controlled by rider inputs. It is already stated in the Article and I quote "free-tilting/ passive -tilting vehicles possess no stability about their roll axis when stationary. To remedy this problem some free/ passive tilters use tilt locks or restraints when at low speeds. Some use a brake applied to the tilting mechanism,some use progressive roll stability adjustments.  This covers the use of springs at stopped and at low speeds. Obviously at stopped the springs could be sufficient to hold the vehicle upright.  And it would of course be possible to use light spring loadings at higher speeds but as yet no examples have been included into the text of the Article that would allow comment.  You also again refuse to acknowledge your disruptive editing with regard your denial of the fact that Active tilters can be controlled regardless of  spring loadings.Cambering (talk) 01:46, 9 January 2020 (UTC)

Table kick-off
SvenAERTS (talk) 15:39, 17 September 2022 (UTC)