Active Suspension On A DIY Racing Car

In automotive engineering, almost every design choice is a trade-off, like performance versus fuel economy, straight-line speed versus cornering, or strength versus weight. Inspired by controversial technology for the 2020 Formula 1 season, [Wesley Kagan] is fitting his DIY racing car with actuators to change the suspension geometry while driving.

The controversial technology in question is Mercedes’ DAS (Dual Axis Steering). By pushing the steering wheel in and out, the driver and change the wheel alignment to toe-out (wheels pointing outwards) for better cornering stability, or neutral for the straight sections.

Like many racing cars, [Wesley] used A-arm suspension on his racing car. By replacing the top arms with telescoping tubes with mounted actuators, the geometry can be actively adjusted. For this proof of concept, he used linear actuators but plans to move to a hydraulic system for improved speed and force. The length of the A-arms is sensed with ultrasonic sensors, while a potentiometer senses the suspension position.

Tuning the software for optimum performance will probably require some track testing which we hope to see in the future. This is not the first time [Wesley] has taken inspiration from a multimillion-dollar project and implemented it in his garage. Just check out how he converted a Miata and a Harbor Freight engine to a Free Valve system.

14 thoughts on “Active Suspension On A DIY Racing Car

  1. As a decades-long Formula 1 follower, this title is misleading: active suspension did existed on F1 in the mid-to-late 80s until it was banned for the 1994 season. 1992 and 1993 cars were the most technological cars that ever ran in the category, it was insane. Williams was the team with the most advanced/polished suspension, so much that it was dubbed by Ayrton Senna (#RIP) “a car from another planet”.

          1. Not true. The current rules revolve around insane infinitesimal optimisations of aerodynamics play to the team with the biggest squad of CFD jockeys. more open set rules (like up to the early 90s) allow much more actual innovation so ‘smarter, not harder’ work allows lower budget teams to succeed

          2. Yes, which is why F1 started enforcing a cost cap for teams. Mercedes success under the current system points to a problem with the sport, not necessarily the competition. F1’s rule book and racing format encourages aero development. Hopefully the 2022 rules will give us closer racing.

            At the end of the day, F1 is entertainment. I want a better show aka closer racing. The idea that throwing out the rule book will result in better racing is ridiculous. Someone is going to show up with an insane competitive advantage and decimate the competition. Fan car anyone?

        1. Or in some cases, whoever can come up with the most creative interpretation of the rule book – and racing has been that way for a long time. Look up some of Smokey Yunick’s stories for some great examples. One story was a time NASCAR in the early 1960s set a rule for a maximum fuel tank capacity to limit how far cars could go between pit stops. He showed up with a car that could hold about 12 liters in the pipes from the fuel tank to the engine.

          Another tale of creative rule interpretation which I’m sure a lot of Hackaday readers would have seen coming: A rulebook that had a note that “Retuning of the factory ECU via software and/or hardware within the stock ECU housing is permitted.” They were expecting add-on EPROMs of new settings. They got completely gutted ECU cases with completely new circuit boards and processors wedged in.

    1. I remember an magnetostrictive ultrasonic sensor technology for hydraulic pistons. The sound waves are guided in the metal of the piston rod. But of course I do not know, if the author used this.

    2. Laser Tof was how the ride height sensor I worked on for one of the F1 teams worked in the early 2010s. As a plus we used the scatter pattern from the tarmac to measure 2d speed over ground to tell slip and speed. Basically a 200mph, 200khz optical mouse!

      1. Lemme guess, it was something like the insanely expensive Bosch motorsports sensors?
        I’ve been on the lookout for some affordable but still “automotive” rugged sensors for a while for just suspension and ride height measurements and logging.
        Only actually affordable there is seems to be the potentiometer sensors originally meant for automatic headlight leveling, Buuut they’re essentially potentiometers and thus slooow to react.

  2. Hmm, I also wonder about the distance sensor. My first thought was that you could do what BUD satellite positioners did: just count pulses from the rotation of the actuator motor, combined with at least one limit switch to give a base count. However, mention of an optical setup suggests an even easier idea: Shine a laser pointer at a slightly angled mirror on the other end; catch the reflection with a lateral-effect photodiode. The output will correspond to the distance.

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