Welcome to my build thread. This is my first attempt at building a ardurover based on APM 2.5. The RC platform I am building on is an Axial SCX10 rc crawler (2012 Jeep Rubicon). The end goal I am aiming for is large obstacle avoidance. Where this drone can determine if it’s possible to crawl over an object, or have to move around (such as when it cannot get enough traction to climb over an object). I am to understand that for advanced obstacle avoidance and drone orientation to determine if a change of route is required will require the use of something like Raspberry Pi. I own a new Raspberry Pi which I am not using, but would be glad to try in the future. The other thing I am trying to accomplish is keeping everything under the body. This requirement may push me to bump up to quarter scale vehicle. Keeping everything under the body will provide a larger possibility of keeping things protected in case of rollover.
Parts List
Axial SCX10 Jeep Rubicon
Pro-Line Cherokee Body
Spectrum DX5e 5 ch w/momentary switch
Spectrum 6 ch receiver
APM 2.5 w/Telemetry (915Mhz) & Power Module
5.8g 200mw FPV Wireless AV Tx & Rx
1/3-inch SONY CCD Video Camera (NTSC)
NiCad 3000 mAh battery
Li-Ion 1100 mAh battery
I have made use of the crawler as it is for the last month, and see that some things need to be modified. I am strongly considering some changes to the suspension and drive train to improve the crawler’s ability to climb obstacle. This includes wider axles from an Axial Wrath. Longer suspension links to stretch the wheel base. Longer shocks to lift the crawler. Slightly larger tires to lift the axles further off the ground. And rotating the axles to lift the pinion to point more towards the t-case to minimize drive shaft joint angles.
Currently, the motor and battery system I have now allows for a bit over 2 hrs of run time. On this note, the final thing which needs to be looked at is adding a second motor and a better battery solution to ensure the added weight doesn’t impact performance an drive time in a negative manor.
Thanks for reading,
John
Replies
Evening everyone. Well, not that it was needed, but I just updated to APMRover 2.41. Doesn't look like there are any changes which will assist me in GPS accuracy, but its been done anyways.
Based on some prior comments, I will be focusing my work towards reducing EMF interference. Of course, I will be posting to this thread what I find. There is a possibility that I need a better GPS module, an if that's the case I will accept it as is an update it later this year.
Meanwhile, I have been having a lot of fun playing with the FPV system an working on the antenna an transmitter power system. I suspect it needs a 3s li-po an a better receiver antenna to ensure longer range than 30 yrds. 5.8Ghz should do better than that.
John
@TC & @ Alan,
Both of you bring up a good point. Below I provided 2 pictures of my setup. I may have the APM too close to the motor. Hmm, wander if a copper mesh between the 2 would help?
My motor is on the left side of the rig in the middle. The Battery is in the rear of the rig above the rear axle. The ESC is in the middle of the rig towards the front, just behind the front axle. That is also the location of the Telemetry transmitter. As you can see in the first pic, there is an antenna going thru the plate in front of the rc receiver. All of that is below the aluminum plate. Uptop, the Vid transmitter is towards the rear.
Before going thru the effort of spiting the compass off, is there better planning of Electronic placement I can try? I really wanted the GPS unit upfront, where it sits under the hood of the Cherokee body. The other major bonus to this was I can use my camera an look down to see my APM, RC Receiver, an GPS lights via FPV.
John
@Thomas,
Thanks, I'll check it out.
Alan KM6VV
How about the compass? Has anyone tried moving it up and above the 'bot? It's probably more subseptable (sp) to magnetic influences from the 'bot then the GPS. However, it is not on its own cable.
Alan KM6VV
@Bot_Thoughts & @TC,
As explained much earlier in this thread, I used a 18in x 6 inch piece of aluminum sheet metal to stick all my components to. My GPS is currently sticky tapped to this for the time being. Should I consider using nylon spacers an bolting the GPS to the aluminum plate?
@Bot_thoughts,
I was building this on a budget for now to get me started. I would like to upgrade to the other option provided by 3dRobotics soon. Most importantly, I am looking to understand the limitations of my hardware. An making sure I myself am not causing my own problems. The reason for sticky taping things is so that I can go thru this learning curve an then move things to their final location an come up with a better mounting system.
To both, many thanks for your comments an assistance.
John
What is the expected accuracy of the MediaTek GPS unit? I turn on my Rover in the middle of the road, an move in to the yard an select RTL an the rover moves to about 15ft of the point I turned it on.
I have all my parts sitting on a metal plate, an I have receiver wires (which goto the APM) over the GPS unit. Could that be causing me issues? An every thing is under a plastic body. I do live in the woods, could I be dealing with interference for that reason?
I bought the cheapest GPS unit sold with the unit, an I can accept that as being it.
thoughts?
John
So I ran the crawler with the FPV system. TC was correct in the need for a 900 MHz system. I am stuck with what I got for now, an I will be powering it with a 3S Li-Po battery an making changes to the antenna's as when I can afford to purchase a new charger for the battery an materials to deal with the antenna's.
So next on my list of things to do is learn the capability of Mission Planner. An test the APMs ability. This weekend most likely will be un eventful as I am installing a new Engine in my 92 Wrangler. I have gone all winter with out my YJ while I drove the 97 Cherokee (XJ), an really looking forward to running around topless in style :-) I am truly a Jeep guy.
John
New update. I got the FPV mount servo in place an will be re mounting all the hardware in the final place this evening. Hope to be testing the FPV system this evening. Then get more time testing the APM Modes this weekend. My last day at work is today, an it looks like I will have this next week with plenty of free time. Hopefully I can get to a open field an do some testing on the entire system as a whole.
John
I finally got my FPV setup tested an working. So now its time for me install the camera in the Crawler/Drone. Def will take some thought. More images to come this weekend.
John
New news regarding my Rover. I got the wiring built for the FPV system. I am sorting out battery issues an requirements, then I perform final fitment.
I am still looking for answer as too why I can not change flight modes via MP. It looks like the application is suppose to be capable of it.
John
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