Some driving questions

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minionhunter
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Some driving questions

Post by minionhunter »

Hi

I'm pretty new so I will likely be asking some simplistic questions. One that occured to me from watching drivers face off in the arena is what exactly am I watching?

I've read about mixing (either on a chip or on the bot) making all steering (forward, reverse, back, forward) on one stick. I think I have this right.

I've read about inverted driving being handled via chip (automatically setting the controls to recognize the inverted situation and adjusting so that you don't have to change the way you drive). I think I have this right. I'm not sure but I would guess that you can program this on your own tx as well but I don't know how it would be detected other than flipping a switch.

What I don't know about are two things I think I've seen.

First, one contest when I saw some really good drivers were using 6WD bots they appeared to be moving in slow motion at first. They appeared to be using a different speed initially for more precise driving when their bots could easily drive at double the speed. Was this a setting on their tx they could use and immediately switch out of if they needed to shove the other bot? Or were they just so good they were just using their throttles to adjust the speed? All motions looked so fluid and slow that it looked like they were using a "different gear" or setting.

Similarly sometimes a driver will execute a precise 180 degree turn in a way it looks like they had a setting for it, to just execute the 180 perfectly and then they drive. Is it the case they have a program with it or are they just so good and experienced that they can pull off a perfect 180 whenever they want?

Thank you for any help you can offer me.

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Shakey
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Re: Some driving questions

Post by Shakey »

minionhunter wrote:
Mon Jan 20, 2020 6:01 pm
I've read about mixing (either on a chip or on the bot) making all steering (forward, reverse, back, forward) on one stick. I think I have this right.
Mixing isn't necessarily moving it all to one stick but simply the act of making one channel a forwards/backwards and another steering (Making those channels influence both sides of the drive each rather than only 1 side)

minionhunter wrote:
Mon Jan 20, 2020 6:01 pm
I've read about inverted driving being handled via chip (automatically setting the controls to recognize the inverted situation and adjusting so that you don't have to change the way you drive). I think I have this right. I'm not sure but I would guess that you can program this on your own tx as well but I don't know how it would be detected other than flipping a switch.
Most the time this is handled by a switch being flipped. Though I've never actually felt the need for one in all my robot fighting, I programmed one once but found it just got in the way more than simply driving accordingly when the bot was upside down.
minionhunter wrote:
Mon Jan 20, 2020 6:01 pm
First, one contest when I saw some really good drivers were using 6WD bots they appeared to be moving in slow motion at first. They appeared to be using a different speed initially for more precise driving when their bots could easily drive at double the speed. Was this a setting on their tx they could use and immediately switch out of if they needed to shove the other bot? Or were they just so good they were just using their throttles to adjust the speed? All motions looked so fluid and slow that it looked like they were using a "different gear" or setting.
I think I know the actual bot this comes from but I'm kinda just going to sidestep it as that bot actually had a err... 'Quirk' of the control system that led to this. You *could* set this up with whats called 'Dual rates' which is where you can make a switch on the TX change the % the stick will actually go to, but again having to deal with a switch can get in the way. 'Exponentials' are a bit of a better version that kind of changes the sticks travel to be not linear (Ie the percent of speed the bot is doing is no longer directly what the stick is at), it kinda squishes the faster speeds up at the top of the stick and spreads out the slower speeds, it trades fine slower control for worse fast control. But since when you're going fast it normally is full stick it doesn't matter. Mostly though I do neither and just manually control the bot faster or slower.
minionhunter wrote:
Mon Jan 20, 2020 6:01 pm
Similarly sometimes a driver will execute a precise 180 degree turn in a way it looks like they had a setting for it, to just execute the 180 perfectly and then they drive. Is it the case they have a program with it or are they just so good and experienced that they can pull off a perfect 180 whenever they want?
Just a lot of practice! To add though you'll find robots with 4WD (or more) turn much more precisely than 2WD bots, though a little slower at it, not to say a 2wd bot can't turn precisely but the drives nature results in 4WD doing it better.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!

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LimaHotel
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Re: Some driving questions

Post by LimaHotel »

Shakey pretty much covered it! I'm gonna have a bash at breaking down mixing a touch more (in case it's needed). Essentially, your receiver will receive a signal from your transmitter and then output a signal that relates to what the stick position is of each channel. Now this means that up on the right stick (what most people use for forwards) is actually just saying "signal up on the elevator channel". Each side drive will be on a different channel - if you want your driving on the right stick then you might have left hand drive on elevator and right hand drive on aileron. Without mixing, up on the stick would make left drive go forwards, right would Make right drive go forwards, etc. This is undriveable.
Mixing mixes the signals, such that up on the right stick actually outputs up on both the aileron and elevator, right outputs up on elevator but down on aileron, down outputs down on both, and left outputs down on elevator and up on aileron. Some dual escs already do this, and sometimes you need to get your tx to do it. The Fs-i6 just has an option you turn on and bam it seems to work fine, whereas the devo needs it programming using the not particularly user friendly interface. This does mean you can do some fancy mixing on your devo, but most bot builders would never need it.

With regards to your other questions, it's honestly just practice. Driver skill decides matches way more often than bot design does. Heck, there are some drivers here I'm convinced would be able to beat me at my best using nothing but a half empty tub of Margarine!
Jiggy Sawdust
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The Pushbot from Mars

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Shakey
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Re: Some driving questions

Post by Shakey »

LimaHotel wrote:
Mon Jan 20, 2020 6:31 pm
With regards to your other questions, it's honestly just practice. Driver skill decides matches way more often than bot design does. Heck, there are some drivers here I'm convinced would be able to beat me at my best using nothing but a half empty tub of Margarine!
To add a bit more, it's often why many people can never agree on a 'perfect design', because driver skill is such a big part it often comes down to what kinds of bot the individual driver is best at. And even down to the minor details, even the armour arrangements people prefer can come about as it works with how they drive.

I know if I handed my robot team over to someone else for a comp different bots from the team would do better than others simply because that driver may be better with different bots in the team than I am.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!

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MarkR
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Re: Some driving questions

Post by MarkR »

It is theoretically possible to have automatic invert when the robot is turned over, if the mixing is done onboard by a microcontroller which also has an accelerometer which can sense its orientation.

I'm not sure that would be advantageous.

I have a robot (Betsie) which has the required processing and sensor, but I've never implemented it because it doesn't drive well upside down and can self-right pretty easily.

Also, Betsie's "super clever" control system (which uses gyroscopic stabilisation) causes it to drive like a pile of dog poo. I have tried many changes to the control software to improve it, but I've never got it to be very usable. I'm beginning to think that putting more intelligence into, at least an Antweight combat robot, is generally counter productive.

---

It is possible that more intelligence is more useful on a bigger robot because:
* Fights tend to be slightly slower and more tactical in the bigger classes
* Complex electronics give less of a weight penalty on a bigger robot (The Raspberry Pi zero W which I have in Betsie weighs about 9g, and needs other electronics just to give it clean power)
* Also power consumption of gubbins is more of a problem in Antweight, in Betsie I have ~ 100mA idle current which means I can't turn the robot on too long before the fight otherwise I'll run down the battery
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands

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Shakey
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Re: Some driving questions

Post by Shakey »

MarkR wrote:
Mon Jan 20, 2020 6:50 pm
Also, Betsie's "super clever" control system (which uses gyroscopic stabilisation) causes it to drive like a pile of dog poo. I have tried many changes to the control software to improve it, but I've never got it to be very usable. I'm beginning to think that putting more intelligence into, at least an Antweight combat robot, is generally counter productive.
I've often found it's more important for something to drive predictably than intelligently. I'd rather take a robot that pulls to the side every time it goes forwards than one that sometimes manages to correct for it but not consistently.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!

minionhunter
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Re: Some driving questions

Post by minionhunter »

Shakey wrote:
Mon Jan 20, 2020 6:53 pm
MarkR wrote:
Mon Jan 20, 2020 6:50 pm
Also, Betsie's "super clever" control system (which uses gyroscopic stabilisation) causes it to drive like a pile of dog poo. I have tried many changes to the control software to improve it, but I've never got it to be very usable. I'm beginning to think that putting more intelligence into, at least an Antweight combat robot, is generally counter productive.
I've often found it's more important for something to drive predictably than intelligently. I'd rather take a robot that pulls to the side every time it goes forwards than one that sometimes manages to correct for it but not consistently.
Thank you all very much for your help! I really appreciate it.

In that it is down to driver skill is really encouraging because that can be learned from practice and experience. That's great! I wasn't quite sure because some of drivers skill is really amazing, they look like what you would think a perfect computer would.

Based on the answers for mixing and in that I'm getting a set of FS i6 transmitters to start with, I think I just need to buy them, the rx for them and get building and start practicing with the kids. For a beginner that transmitter sounds just about perfect (with the mods for rechargeable batteries and better gimbals).

Thank you all again for your time and help. You are really wonderful and generous to answer my questions and I am grateful. I'm trying my best to only ask ones that I can't find the answers to myself.

minionhunter
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Joined: Fri Nov 04, 2016 5:36 pm

Re: Some driving questions

Post by minionhunter »

Shakey wrote:
Mon Jan 20, 2020 6:16 pm

minionhunter wrote:
Mon Jan 20, 2020 6:01 pm
First, one contest when I saw some really good drivers were using 6WD bots they appeared to be moving in slow motion at first. They appeared to be using a different speed initially for more precise driving when their bots could easily drive at double the speed. Was this a setting on their tx they could use and immediately switch out of if they needed to shove the other bot? Or were they just so good they were just using their throttles to adjust the speed? All motions looked so fluid and slow that it looked like they were using a "different gear" or setting.
I think I know the actual bot this comes from but I'm kinda just going to sidestep it as that bot actually had a err... 'Quirk' of the control system that led to this. You *could* set this up with whats called 'Dual rates' which is where you can make a switch on the TX change the % the stick will actually go to, but again having to deal with a switch can get in the way. 'Exponentials' are a bit of a better version that kind of changes the sticks travel to be not linear (Ie the percent of speed the bot is doing is no longer directly what the stick is at), it kinda squishes the faster speeds up at the top of the stick and spreads out the slower speeds, it trades fine slower control for worse fast control. But since when you're going fast it normally is full stick it doesn't matter. Mostly though I do neither and just manually control the bot faster or slower.
I can't be sure the exact bot, and in my mind it is a few bots (or drivers) that can do this. I remember pretty clearly a match (final maybe?) where the mostly clear/transparent bot with the purple or UV "headlights" was dueling with another bot that was also 4 or 6WD. The other bot may or may not have had headlights and if it didn't it might have had them added later in a different match.

I'll try to find it. I'm nearly positive it was an AWS in the mid to late 40's, I think before wedge wedge wedge was introduced.

minionhunter
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Joined: Fri Nov 04, 2016 5:36 pm

Re: Some driving questions

Post by minionhunter »

minionhunter wrote:
Mon Jan 20, 2020 7:55 pm
Shakey wrote:
Mon Jan 20, 2020 6:16 pm

minionhunter wrote:
Mon Jan 20, 2020 6:01 pm
First, one contest when I saw some really good drivers were using 6WD bots they appeared to be moving in slow motion at first. They appeared to be using a different speed initially for more precise driving when their bots could easily drive at double the speed. Was this a setting on their tx they could use and immediately switch out of if they needed to shove the other bot? Or were they just so good they were just using their throttles to adjust the speed? All motions looked so fluid and slow that it looked like they were using a "different gear" or setting.
I think I know the actual bot this comes from but I'm kinda just going to sidestep it as that bot actually had a err... 'Quirk' of the control system that led to this. You *could* set this up with whats called 'Dual rates' which is where you can make a switch on the TX change the % the stick will actually go to, but again having to deal with a switch can get in the way. 'Exponentials' are a bit of a better version that kind of changes the sticks travel to be not linear (Ie the percent of speed the bot is doing is no longer directly what the stick is at), it kinda squishes the faster speeds up at the top of the stick and spreads out the slower speeds, it trades fine slower control for worse fast control. But since when you're going fast it normally is full stick it doesn't matter. Mostly though I do neither and just manually control the bot faster or slower.
I can't be sure the exact bot, and in my mind it is a few bots (or drivers) that can do this. I remember pretty clearly a match (final maybe?) where the mostly clear/transparent bot with the purple or UV "headlights" was dueling with another bot that was also 4 or 6WD. The other bot may or may not have had headlights and if it didn't it might have had them added later in a different match.

I'll try to find it. I'm nearly positive it was an AWS in the mid to late 40's, I think before wedge wedge wedge was introduced.
Bots I've seen drive this way (at times) in a quick scan of AWS matches

"Monkey face" what my kids call the bot with 4WD inward slanted wheels, good driving

Clear bot with the purple/UV headlights and a flipper

Bot with a giant 4 printed on the top in yellow - this one really looks like a computer is driving at times, mostly slow though


Red headlights with black wheels 6WD - really enhanced 180 turning effect (looking at it)

White and clear 6WD bot - really pronounced driving slow to super fast transitions, mesmerizing at times (like "how did he just do that")


4WD yellow flipper sometimes


I still haven't found the specific fight I'm thinking about yet, I think it is the clear purple bot, the white 6WD and the red headlights bot mostly with the one with the giant number 4 on it that also has a weird effect.

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