RC Car Active Suspension - Test Rig Pt4

In this video we continue the development of a radio controlled car active suspension by creating a miniature suspension test rig. #3dprinting #rc #motorsport

[@ericlotze7724]

Amazing Project!

[@ericlotze7724]

If I remember correctly, there was an F-1 Car that used Active Suspension and either Pre-Scanned Maps and/or LIDAR or something to “hug the ground”. Granted it was very difficult for them to pull off with all their funds+capabilities, but I’d imagine this could do something similar?

[@IndeterminateDesign]

That’s the hope someday. From what I’ve read on the F1 cars they had the pre scanned maps and they used load cells integrated into the pushrods. I can’t find a lot of information on what F1 teams would use today. I imagine cameras and real time laser scanning but I’m not sure.

[@Cor_Netto]

Really cool stuff!

[@javier95mb]

This videos are top notch, keep it goin man

[@wildgophers91]

Yesssss. I love this idea

[@bertanderny]

Amazing that you're continuing this, makes me want to try it myself. Saw you comment own the mode decoupled video, would be great to see you tackle that especially the way you put your videos together

[@IndeterminateDesign]

Thanks. I’d love to do the decoupled suspension someday. I really need an SLA printer for that and it’s a bit too messy for the small space I have right now.

[@fruechtekorb]

As usual, a great video. And yes the Integration constants will give you problems. One solution might be mounting a camera on the car and do a visual flow analysis and use booth guesstimates in a Kalmann filter. OpenCV can do visual flow I believe. And I believe also that you can feed the Kalmann filter with differenent data rates.

[@IndeterminateDesign]

Thanks. I hadn't though about the camera. I'll check out OpenCV. If it supports contours/edge detection I maybe able to do it with just that with the added bonus of being able to have terrain preview.

[@Liberty.Francis]

Really amazing work and I know this has hundreds of hours invested. I recently got my 1/7 speed car to 126mph on 3s. Going to push it into the 130s this weekend.

[@IndeterminateDesign]

That’s awesome! That thing must be a beast. I’ve always loved the larger scale cars like that. I’m working on getting my streamliner more reliable right now. I’ve been able to run it a lot but just don’t have the space to get much over 80mph. I think I may change directions and switch to AWD.

[@Liberty.Francis]

@@IndeterminateDesign AWD is critical for braking.

[@chisengamisengo3776]

Can I buy this whole set up like it is ?? Please

[@gren509]

I'm lov'in this !! The acceleration plot is horribly jumpy, might this be due to the hard tire being imperfectly round ? You could try this using a non-eccentric roller and seeing if the spikes are still there. In terns of overall damping, the next calculated vertical position needs to be the last position, plus the velocity, plus change in speed between the last 2 positions, as a basic calc.

[@IndeterminateDesign]

Thanks. I had a lot of issues with the MPU6050 sensor, and as I found out in the next video the backlash in the system also causes some issues. I'm planning on buying a better sensor that actually has all of the filtering and sensor fusion built it and actually directly will output a velocity. I figured for a few extra bucks it would make my life a lot easier. Thanks for the tip on the damping calc and I'll add that to my chart that I did in the next video.

[@Firashelou]

This is purely amazing ! You are an engineering genius ! Btw i have an idea t make a suspension rig for my phoenix f1 car also similar somehow to the redbull f1 rig on youtube but without any data just visual and test the suspension if it works well

[@IndeterminateDesign]

Thanks! Let me know how it works. I had plans to build a 4 wheel test rig with eccentrics, but I had a moment of clarity and realized I should start small with one wheel first.

[@Firashelou]

@@IndeterminateDesign sorry just got a notification that you replied ! sure when it is done i sure will share it !

[@qwer.ty.]

Active suspension with knowing the GT (Ground truth) is not a good idea in my opinion. Also the basic suspension doesn't have any spring and damper. You might want to find a better distance sensor and work with pseudo random road imperfections, well that's what I'll do ^^

[@IndeterminateDesign]

Thanks. Yeah I just set this up as a test of the rig mainly. I need to add a spring and damper or a much faster actuator. The plan is to try skyhook and groundhook again and see if I can tune them better. I think the distance sensor is really only useful for large disturbance detection and managing ride height.

[@qwer.ty.]

@@IndeterminateDesign you can try a dual core MCU (esp32 wroom32) to do things in parallel for a very important sensor!

[@user-jg5lo5pf5c]

could you please explain if the control goal is to make the vehicle body still (no displacement) or to make the acceleration zero?

[@IndeterminateDesign]

This particular test was more of an actuator test and thus was just mathematical. The control goal is based on what you want the suspension to accomplish. If you minimize the sprung mass velocity you increase ride comfort. If you minimize the unsprung mass acceleration, you increase handling performance. In my later videos using controllers that minimize the acceleration of either the sprung or unsprung mass depending on the selected controller.

[@wildgophers91]

Instead of a potentiometer have you thought about using a linear encoder?

[@IndeterminateDesign]

I would love to use a linear encoder. I hate potentiometers, but I haven't been able to find a good linear encoder to use with Arduino. Most of them are meant for CNC machines or $100+. If you know of any let me know, I only need 30-40mm of travel.

[@LordsavageSnow]

Yes please 🙏