Govenor, How does it work?

[mjdee14]

Does anyone know how the govenor setting works. ? I mean is it trying to keep a preprogrammed RPM?

From what I have seen....if I fly around in normal for a while then hit IU my RPM's are a lot lower than if I hit IU just before takeoff.

So my thoughts are the govenor is trying to hold whatever RPM is first introduced depending on the voltage available at the time. Lipos usually start out at 25 volts or so...and go down pretty rapidy to 22 or so. So if you hit IU at the 25volts the RPM's will be higher and the gov tries to keep that high HS.

If you fly around and hit IU when the voltage is already down..the RPM's are much lower.

At least that's what I see on the Eagle tree. one is with pack volts the other is just RPM. I didn't realize till I counted I did 11 auto's.... But the rpm's are lower in IU than in the past before I flew in normal for a while.

Any onehave any thoughts on Govenor mode...i'm using the Gaui 50 amp ? :thinking

lipos from left to right are 2200 hextronic, 2nd & 3rd 2500 polyquest, 4th 3300 polyquest, 5th 3300 zippy's.

[michael88997]

yea i dont understand it either lol... i fly at 100% tc so it cant get any more power and im not worried about overspeeding so whats the point

[HFG]

http://helifreak.com/showthread.php?t=64727

The last few sections cover esc stuff.

[mjdee14]

http://helifreak.com/showthread.php?t=64727

The last few sections cover esc stuff.

HFG...nice explanation, BUT, can you expand on what I was asking about RPM?

I'm running a normal curve of 0, 50, 65, 65, 65 and an IU1 of 85% across.

So is the esc looking at voltage available and setting RPM with vol X KV?

So it's different depending on when you go into IU?

It just seems if I hit IU on the ground, I have a much higher HS than if I fly around a while then hit IU

[HFG]

It really depends on the exact implementation to determine the relationship between the throttle position and RPM.

[worldofmaya]

Hi!
First off, why you fly a normal curve like that? If you're in one of the Heli modes than just use a flat 0 curve, switch up to Idle1 if you wanna fly and your Esc should have a nice soft start to spool up.
The second thing is that I can't really see your RPM curve... post an image with only one session enabled! There's an menu entry where you can select that. From the way it looks right now, you curve is pretty much okay. A single session would be nice to really judge that.
About governor, at spool up the Gaui goes a bit higher and than goes back down to the level set via throttle channel. Thats how this Esc works. That should be in the first few seconds after spool up. Than the curve varies based on how much power you need. If the Esc can't hold rpm, rpm will drop. If you have your packs amps curve enabled you can see how this curves affect each other. If you now enable your packs voltage you can see how this voltage drops too.
Another thing you should see is that head speed drops without real usage... just try to hover and log that. You'll see that rpm drops together with pack voltage. This should be around 50rpms during a session...
-klaus

[Phoinix]

Governor mode works in combination with available pack voltage. When your packs vltage droops, governor goes down a bit on the RPM, as it can't use the voltage that won't be there when needed.

This is how it was explained to me.

[ianjh123]

There are a number of different governors around. My Quark ESC remembers the rpm it sees when you press the button on the side (I use an optical tacho to press the button at the right rpm), and will try to maintain that programmed setting no matter what the pack volts are. The good thing is that it maintains head speed very well. The bad thing is that it takes a second or so of low throttle to drop out of governor mode (bad in crashes).

[bearwood]

Ok, so if I have this right the Governor needs some headroom to operate in to maintain the headspeed. The governor rpm is set by the ESC and is adjustable in some ESCs.
So even though we might have a 100% headspeed of say 2000rpm most of the flying is actually flown at the governed headspeed (1800rpm at 80% governed) and the rpm above the governed headspeed is only used to maintain power when applying extra load to the motor i.e pulling pitch.
So governor mode is for 3D/sport flying? or any time you go into a Idle Up flight mode? (which is pretty much the same thing to me)

[HFG]

No you arn't understanding how it works. The gov increases the throttle to maintain a constant headspeed. So lets say the HS is 1800 at 75% throttle, when you start to bog load the head during a trick or something the HS will start to drop. The gov will increase the throttle from 76-100% to keep the HS at 1800.

[ianjh123]

I'd say you have it right about needing some headroom to maintain rpm. The main advantage with a governor is that you don't need to play with throttle curves and pitch curves. Once the governor is on you can use a linear pitch curve. The whole point of playing with throttle and pitch curves is to keep a constant head speed under all loads anyway. The main disadvantage is shorter flying time as it takes more energy to maintain the constant head speed with a governor.

I'm not sure of the terminology on your radio but JR radios refer to the flight mode switch which has normal/stunt 1/stunt 2. I take off and land in normal and fly in stunt 1, which I set to a flat throttle curve to keep the governor on.

[HFG]

I have to disagree with the gov mode resulting in shorter flight times. If anything you should be getting longer flight times. Often we run a MUCH higher HS without the gov function to compensate for the fact the HS will drop when load.

[skigolfmike]

It depends on what you want to do.

In Gov Mode I found the heli to hover a lot better and transition in and out of normal flight. it was also good for aerobatics and mild 3D. The only problem I had was that on an electric motor the way it works on an ESC seems to mess with the tail. It took a lot of time and patience to get the gain right for me to get Gov Mode to work. Even then I had to turn the gyro gain down and the tail didn't hold as well. More on gain later.

For the most part, the guys flying hard 3D w/ electrics are using a 100% flat throttle curve and gearing for the headspeed they want. Then they use their excellent collective management to use the rotational energy in the rotor to throw the heli around. What they are good at is getting back to 0* pitch and keeping the head speed up.

The explanation I got for not using a governor on an electric has to do with electric motor power curves. Electric motors make maximum torque at 0 rpm and min torque at max rpm. Theoretically, max HP is at 50% rpm, realistically, it's about 60-65% rpm. The sweet spot on gearing for Gov Mode is usually about 75-80% rpm, which is way on the back side of the power and torque curves.

So, your spinning the head at 2200 in gov mode, which is about 80% throttle in fixed endpoint mode. Now you hit full collective, the rpm starts to drop, the ESC senses the drop and reacts by increasing the throttle % to try and keep the rpm from dropping. However, even if the governor gives 100% throttle at this point, since the motor is on the back side of the power curve, the rpm is very likely to drop.

With a 100% flat throttle curve, the motor doesn't have to wait for the ESC to sense anything. Hit full collective, load on motor increases, amp draw goes up and RPM starts to drop. Take the load off the motor and, wham, back to full rpm.

The reason the governor isn't as good for hard 3D is the governor gain. The governor senses and reacts, but the gain controls how fast the ESC reacts. 100% flat doesn't have to react, it's already there.

I was going to use the gov mode on my Phoenix HV85, but, knowing what I know now, I probably won't. Down the road, I may even replace this monstrosity with a smaller 75-80A ESC.

[HFG]

The sweet spot on gearing for Gov Mode is usually about 75-80% rpm, which is way on the back side of the power and torque curves.



But 100% will be even further !! I can only comment about flying gov vs non-gov on my 450. With proper collective management i can't tell any different when the HS are the same. Running 100% has nothing to do with the torque of the motor, you run a really high HS to store energy in the blades that you can bleed off with a quick trick then let it build back up before doing another.

[skigolfmike]

True, but...

Electric motors always seek equilibrium at max rpm. The 100% flat throttle curve is already there and unloaded the motor will spool bake up very fast. OTOH, the gov has to sense a change then ramps up to 100% based on gov gain, it's not going to spool back up when it bogs as quick as the 100% flat will. Frankly, there's not that much difference in torque between 80% and 100% throttle anyway, and torque determines acceleration anyway.

All I know is guys like Sazbo or Krause run 100% flat in their electric helis and no gov. if gove on an electric was better, I think they would run it.

[HFG]

Your missing the subtlety of how a gov really works. The gov doesn't have to ramp up at all and its agility is only limited by the closed loop bandwidth (esc gov gain is a small part of this). Remember with a gov your running the same HS as with 100% unloaded, you will be using a larger pinion. In the case of 100% the motor can't draw any more power then its already using and cannot recover from a bog until you unload the heli. With a gov you still have 15-20% more power in reserve, which means it can recover form the bog DURING the bog.

[skigolfmike]

I used to think about it the way you are. I had a discussion about this with Finless the other evening and he changed my mind about gov mode. (Of course he still thinks the Hurri 550 is a POS too. I humbly disagree.)

From experience, if you can go up a tooth on the governor and it works better, you can also go up a tooth with 100% flat and it will be even better.

Ping Finless, don't tell him you fly a Hurri 550.:thumbup:

[ianjh123]

HFG, please compare apples with apples! Two identical helicopters, one with throttle curves and one with a governor set up to acheive the same headspeed. The one with the governor must use more energy as it is the only one which can input more energy to compensate for load. Therefore, shorter flight times.

[HFG]

Yes but my point was that with gov mode you can use a slower HS to get the same feeling of power in the air. Because the fixed end point setup CANNOT provide more power you need to run higher HS and store more energy in the blades which means you get shorter flight times. I couldnt care less about numbers likek matching the HS for comparison, all that matter is how it feels in the air.

[skigolfmike]

If you are happy with the way your heli is flying with a governor, then go for it.

When I tried gov mode on another heli with a Phoenix 35, I was never really satisfied with the way the governor worked. I got it decent, but never good. I governor was always pulsing the motor and it really messed with the tail.

I may try it again, but one thing I learned with the CC ESCs is to setup the heli in heli fixed endpoint first, then, when that is working well and consistently, try gov mode. If you don't do it that way you will end up wasting a lot of time chasing too many variables.

[HFG]

If your esc is pulsing the motor then something is very wrong with your setup. Took me a grand total of 5min to setup the CC gov mod to fly seamlessly. With a proper gov mode setup the tail performs ALOT better.

[skigolfmike]

Which CC ESC and which motor? While you're at it, what batteries, gearing and headspeed with what kind and length of blades.

What I found trying to get it to work on the Blade 400 was governor gain was critical. Get the gain too high and the tail would do a fast wag, too low and it was a slow oscillation. Also, if the governor gain was too low it was like there was a hysteresis in the throttle/collective. That took a lot of collective input to fly.

At the best, it did hover well and it was great transitioning into and out of forward flight. It was also neat how constant the head speed remained, a least most of the time.

The B400 had/has some other problems. The stock motor didn't play well with the Phoenix ESC. I had to gear up to get the headspeed I wanted and that was hard enough on the motor that it doesn't run like it used too. I figure I must have gotten it too warm and weakened the magnets. The system would have worked better with a more powerful motor that matched up better with the ESC.

OTOH, I may try gov mode again with the 550 while I'm still running woodies just to keep the headspeed from getting out of control. Right now I have other problems in the heli to deal with, so I don't need another variable to deal with right now.

[Vinger]

CC's gov mode sucks big time, especially the 85HV. They have been promising new firmware for nearly 10 months now, but it remains vapourware!!!

Try the stock Gaui ESC in gov mode, they work really well. Even the cheap chinese nonames work better in gov mode. CC only good for fixed heli endpoint.

[HFG]

CC35 Gov mode works perfectly fine for me.

[ianjh123]

"Yes but my point was that with gov mode you can use a slower HS to get the same feeling of power in the air." - yes, but that doesn't mean the governor mode causes less power to be used, the lower headspeed does that.

"I couldnt care less about numbers likek matching the HS for comparison" - well if you don't compare at the same head speed, you achieve nothing because the biggest factor in power used is the headspeed.

Your basic assumption that using governor mode is linked to getting the same feel in the air is wrong. Most guys trying the governor for the first time do it out of curiosity,and will probably use the same headspeed they are comfortable with. They will then discover that collective response feels sharper, and it is less complicated to set up than playing with throttle/pitch curves, but the cost is shorter flight time. For me, the trade off is worth it, but it won't be for everyone. As skigolfmike said, "If you are happy with the way your heli is flying with a governor, then go for it."