Hello, i'm new to LMR and Robotics in general. Some of you i'm sure have played TF2 and know about the Sentry Bot. and Also, you may know that Weta Workshop have recently built a working (kinda) replica for VALVe.
Now, i can build this, and most likely it will function correctly. However, i need to know what sensors, speakers, and god knows whatever else i will need to get it to Track and Follow my 'target'. Also, will need information on what servos/motors would be needed.
If you are new to robotics, this is a bit much to get started with. What you need now is a microcontroller, a breadboard and a LED. Start with getting the LED to blink and go from there.
I’ve never seen Weta Workshop, until now (looks like a fun place), don’t know what TF2 or VALVe is either.
Ok, now : Speakers aren’t needed to track or follow a target - unless you are using sonar, so I don’t know why you suggested that or how its relevant…
Anyway - there is a variety of methods of locking and tracking…
Here is one of the most simple that I can think of:
get 3 IR Sharp distance sensors mounted on its head - one mounted forward, another slightly left and another slightly right
sweep the head back and forth until a “target” comes within appropriate range
with the 3 IR sensors position the head so that the center/forward sensor is at the minimum range
this can be done with 1 IR sensor, but would require more “overshoot” in the sentry’s action
I’ve done vision tracking before, but it becomes more complicated - it also requires a computer which the IR sensors only need a micro-processor like an Arduino
I’m probably going to sound like a Douchebag by saying this, but i dont really have the knowledge/budget/time to really learn how to do all this from step one, so a step by step guide would be great. I am obviously not asking you to write one xD Just if you know of any threads/posts/websites, that deal with a similar problem and give a walkthrough of how to solve it
Ghillie,
PS, Thank you so much for the advice and Speakers were for the sound in the video, it plays a shooting noise and beeping noise upon Target ID
PPS, VALVe is a games comapny that created Team Fortress 2 (TF2)
How big and what kind of range did you want on this turret? If it is desktop size you could use a few sharp IR sensors. They can detect up to 2 meters but not with pin point accuracy. You would need more than 1 to get decent object tracking like this.
Something more accurate and effective would be 2 TPA81 heat sensors set to detect in horizontal and vertical planes. This turret uses 1 TPA81 set horizontally.
Both sharp IR sensors and the TPA81 can be easily interfaced to most microcontrollers.
If you want a full size turret and/or the best effectiveness you will need a camera and PC with tracking software.
Hey Ghillie I do know Valve and enjoyed the many hours I spent playing TF2, but if you are a beginner and plan to make something similar to what Weta did, that is an incredible undertaking. GroG’s idea, I think, is probably best for this, although you might want sensors with a Bit more range than 2 metres. Have them mounted on top or in the front, one straight ahead, and the other two either angled slightly to either side, or sitting a distance to either side, and point straight ahead.
Have the turret, when it detects an object within range, as GroG said, aim the centre sensor at it, and then if object moves to either side, the final sensor it passes by (left or right one), have the turret turn in that direction until object is seen again. Repeat.
This can easily be acheived with a small microcontroller, but what might be a problem is getting and powering servos to turn it. How big are you going to make this?
And for sound, just a simple beep and shooting sound, a small, cheap piezo would probably work. Failing that, a small, cheap speaker.
It was going to be full size. Its more to show that i am an efficient Engineer, and i have replicated 3D, 2D drawings. I just thought it would be neat to have it actually work. I’m tempted to give it to my school as a Thank You present.
Anyway. Turret Top is going to be ^6kg, range 1 to 3or4 metres. it doesn’t need to be pinpoint, just general direction, so that people know its following them and ‘shooting’ at them
Without a computer? What, do you mean not using a computer to control it, or that you don’t have a computer, and so can’t program chips for it, and so need another method?
Um, yeah, I’m ok with that, but I’m probably not the best person to help you, as I’m no expert here. Still, I’ll try to help where I can
For a range of 4 meters you will need a webcam. Which means you will also need some kind of computer or SBC with a USB host interface. With a full size turret you could simply get an old laptop and put it inside the ammo drum area.
An alternative to webcam + PC is something like the CMUcam. It is expensive considering you could do the same thing with some old hardware most geeks have lying around, but supports blob tracking out of the box and has a built in servo controller among other features.
This is a pretty difficult project if you have no experience.
If you’re planning to build this at full size and in steel, then the weight will be much more than 6kg. If you look at the video 4 grown men are lifting it and I don’t think it’s because they are afraid to drop it. You’re probably looking at more like 50kg.
And if you look at the complex metal work on the base it would probably take you weeks just to machine it. So if you come back with a complete base and a rotating ‘head’ we could probably help you with the servo / stepper and sensor, but I think that is the least of your problems.
Take into consideration the majority of metalwork is on the base/struts and feet. also, i’ll cut down material to reduce weight. But i appreciate your help, and i will return when i have manufactured the Beast xD
I have a computer, but no idea how to program chips xD And thanks for the help. But as i say, i’ll leave this on hold until i have manufactured the turret. Just wish Weta would get back to my emails!!
That a Sensor Array could achieve, 2metres? Presuming accuracy isn’t key. And have you any idea what prices would be for the Webcam/Crappy Laptop or CMUcam would be?
If the plan is to give it to your school, you might also consider if this is something a school would like to have in its hallway. The kids might think it’s cool to have a simulated weapon tracking them, but I’m not sure the teachers would think the same.
You could try You could try ordering one from weta ssame as Valve did . . .
But like Geir says below, we csn help you with controlling servos and the sensors, in terms of the circuit and code.
In answer to your question above, max range of a sensor array, with sharp range finders, the longest I’ve manage to find is 1.5m, tops. But ask around, some people might know longer ones.
And if you’re gonna stick it in a school, how can you be sure it won’t get vandalised or broken by a kid, Day 1?
I’ve just been looking around at some sonar range finders, Ghillie, as opposed to laser ones, and have found some that can go up to 6.4 metres. Perhaps this is more what you want?
It was ‘Gift’ from Weta to VALVe, sort of a friendship symbol, showing mutual respect. And it shouldnt be too hard. And my School is a Private Grammar School, most of the kids there wouldn’t dare break anything. And the Design Tech Dept. are nice people, they’d look after it, keep an eye on it. And from the looks of things, it’s pretty sturdy
