RC car without a top, showing electronics inside.

Fast Indoor Robot Watches Ceiling Lights, Instead Of The Road

October 25, 2021 by Donald Papp 15 Comments

[Andy]’s robot is an autonomous RC car, and he shares the localization algorithm he developed to help the car keep track of itself while it zips crazily around an indoor racetrack. Since a robot like this is perfectly capable of driving faster than it can sense, his localization method is the secret to pouring on additional speed without worrying about the car losing itself.

The regular pattern of ceiling lights makes a good foundation for the system to localize itself.

To pull this off, [Andy] uses a camera with a fisheye lens aimed up towards the ceiling, and the video is processed on a Raspberry Pi 3. His implementation is slick enough that it only takes about 1 millisecond to do a localization update, netting a precision on the order of a few centimeters. It’s sort of like a fast indoor GPS, using math to infer position based on the movement of ceiling lights.

To be useful for racing, this localization method needs to be combined with a map of the racetrack itself, which [Andy] cleverly builds by manually driving the car around the track while building the localization data. Once that is in place, the car has all it needs to autonomously zip around.

Interested in the nitty-gritty details? You’re in luck, because all of the math behind [Andy]’s algorithm is explained on the project page linked above, and the GitHub repository for [Andy]’s autonomous car has all the implementation details.

The system is location-dependent, but it works so well that [Andy] considers track localization a solved problem. Watch the system in action in the two videos embedded below.

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Homebuilt Racing Sim Does Almost Everything From Scratch

December 12, 2020 by Lewin Day 16 Comments

If you desire a sim gaming rig, there are off-the-shelf options up and down the market that stretch as high as your budget can afford. Some choose to eschew this route, however and build their own from scratch. Few people go quite so far as [Popicasa POPStuDio], however.

The first version of the rig is about as hacked as you can possibly get, and it’s a joy to see it built from scrap. The wheel itself and the pedals are all built out of old PVC pipe, with a bunch of old wood screwed together for the frame. A cheap USB gamepad serves to handle input to the PC for the pedals and H-shifter. The H-shifter uses simple power switches, repurposed in an ingenious way to sense gear position. The knob itself is cast out of what appears to be hot glue. Steering is done by connecting the wheel to a flexible shaft that tips a smartphone back and forth, using its internal accelerometers and gyros to sense rotation. It’s not clear how this is tied into the PC running Project CARS, but it’s impressive nonetheless.

Version 2 of the build takes things up a notch, using an Arduino Leonardo to handle steering and pedal functions as a Human Interface Device. There’s also force feedback, via a hefty motor attached to the steering shaft via a belt drive. This version implements an H-shifter as well as paddle shifters too for a more modern experience.

Both builds are unique in the modern era for eschewing CNC or 3D printed parts. It’s all done by hand, taking days of effort, and using only basic tools. It’s refreshing to see such a complex build done with nothing but simple materials and sheer commitment. We’re sure [Popicasa POPStuDio] enjoys the rig, and we can’t wait to see where it goes next. Perhaps the next iteration will even feature a motion platform, perhaps built out of old forklift parts? Only time will tell. Video after the break.

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Fans Add Reality To Virtual Driving

December 5, 2020 by Al Williams 16 Comments

A few decades ago you might have been satisfied with a crude wireframe flight simulator or driving a race car with the WASD keys. Today, gamers expect more realism, and [600,000 milliliters] is no different. At first, he upgraded his race car driving chair and put on VR goggles. But watching the world whiz by in VR is you can’t feel the wind on your face. Armed with a 3D printer, some software, and some repurposed PC fans, he can now feel the real wind in virtual reality. You can see the build in the video, below.

The electronics are relatively straightforward and there is already software available. The key, though, is the giant 3D printed ducts that direct the airflow. These are big prints, so probably not for some printers, but printers are getting bigger every day. The fan parts are from Thingiverse, but the enclosures are custom and you can download them from the blog post.

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Raspberry Pi Helps Racer Master The Track

October 1, 2020 by Tom Nardi 9 Comments

Looking to give himself a competitive edge, racer [Douglas Hedges] wanted to come up with a system that could give him real-time feedback on how his current performance compared to his previous fastest lap time. Armed with a Raspberry Pi and some Python libraries, he set out to add a simple telemetry system to his car. But as is often the case with these kind of projects, things just started snowballing from there.

The Raspberry Pi based data acquisition system.

At the most basic level, his system uses GPS position and speed information to light up a strip of RGB LEDs on the dashboard: green means he’s going faster than the previous best lap, and red means he isn’t. Any interface more complex than that would just be a distraction while he focuses on the track. But that doesn’t mean the Raspberry Pi can’t collect data for future review after the race is over.

With the basic functionality in place, [Douglas] turned his attention to collecting engine performance data. It turned out the car already had some pre-existing equipment for collecting metrics such as the air-fuel ratio and RPM, which he was able to connect to the Raspberry Pi thanks to its use of a well documented protocol. On top of that he added a Labjack U3 data acquisition system which let him pull in additional information like throttle position and coolant temperature. Grafana is used to visualize all of this data after the race, though it sounds like he’s also considering adding a cellular data connection vehicle data can be streamed out in real-time.

In the past we’ve seen onboard data collection systems make real-world races look more like their virtual counterparts, but it seems like the solution [Douglas] has come up with is more practical in the heat of the moment.

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Karting Hands-Free

September 1, 2020 by Brian McEvoy 3 Comments

Some of us have computer mice with more buttons than we have fingers, resolution tracking finer than a naked eye can discern, and forced-air vents. All these features presuppose one thing; the user has a functioning hand. [Federico Runco] knows that amyotrophic lateral sclerosis, ALS, or Lou Gehrig’s disease, will rob a person of their ability to use standard computer inputs, or the joystick on a motorized wheelchair. He is building EyesDrive for the 2020 Hackaday Prize, to restore that mobility to ALS patients. There are already some solutions, but this one focuses on a short bill of materials.

Existing systems are expensive and often track pupil location, which returns precise data, but EyesDrive only discerns, left, right, and resting. For these, we need three non-invasive electrodes, a custom circuit board with amplifiers, signal processing circuits, and a microcontroller. He includes a Bluetooth socket on the custom PCBs, which is the primary communication method. In the video below he steers a virtual kart around a knotty course to prove that his system is up to the task of an urban wheelchair.

EyesDrive by [Federico Runco] should not be confused with the HackadayPrize2015 winner, Eyedrivomatic, lead by two remarkable hackers, Steve Evans and Patrick Joyce.

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Feel The Virtual Road With Force Feedback

November 22, 2019 by Gerrit Coetzee 7 Comments

When you’re driving your virtual supercar around the Italian countryside the last thing you want is an inauthentic steering wheel feel, that’s where Open FFBoard comes in. Racing game enthusiasts will go to impossible and sometimes incredibly expensive lengths to build extravagant simulators. [Yannick] feels many of these products are just a little too pricey without much need.

Right now his board is still in a process of iteration, though it can integrate with Assetto Corsa already. You can see in the demo video after the break that it responds quite realistically to the video game state, however problems keep cropping up in search of solutions. Motor drivers burn out and power resistors are added: that energy has to go somewhere. Next up will be switching to the increasingly popular Trinamic drivers. Either way we can’t wait to see the next revision and to get another amazing simulator build sent in to us, maybe centered around the Open FFBoard.

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Electric Vehicles On Ice

August 16, 2019 by Sharon Lin 10 Comments

This winter, a group of electric vehicle enthusiasts, including [Dane Kouttron], raced their homemade electric go-karts on the semi-frozen tundra nearby as part of their annual winter tradition. These vehicles are appropriately named Atomic Thing and Doom Sled, and need perfect weather conditions to really put them to the test. You want a glass-like race track but snowfall on ice freezes into an ice-mush intermediate that ends up being too viscous for high-speed ice vehicles. The trick is to watch for temperatures that remain well below zero without snow-like precipitation.

The group is from the community makerspace out of MIT known as MITERS and already have EV hacking experience. They retrofitted their VW Things vehicle (originally built for a high speed electric vehicle competition) to squeeze even more speed out of the design. Starting out with an 8-speed Shimano gearbox and a 7kW motor, they assembled a massive 24S 10P battery out of cylindrical A123 cells salvaged from a Prius A123 Hymotion program. This monster operates at 84V with a 22AH capacity, plenty for power for the team to fully utilize the motor’s potential.

The battery is ratchet strapped to the back of the Atomic Thing to provide more traction on the ice. It must feel just like riding on top of a different kind of rocket.

Original configuration of battery packs

Battery packs ratchet strapped

They tried using ice skates in the front of the Atomic Thing, but the steering was difficult to control over rough ice. Studded solid tires perform quite well, resulting in less jarring movement for the driver. Doom Sled is a contraption built from a frame of welded steel tube and a mountainboard truck with ice skate blades for steering. The motor — a Motenegy DC brush [ME909] — was salvaged from a lab cleanout, transferring power to the wheels through a chain and keyed shaft. The shaft-to-wheel torque was duly translated over two keyed hub adapters.

The crew fitted a seat from a longscooter and made a chain guard from aluminum u-channel to keep the flying chain away from the driver’s fingers. The final user interface includes a right-hand throttle and a left-hand “electric brake” (using resistors to remove the stored energy quickly to combat the enormous inertia produced by the vehicle).

Overall, ice racing was a success! You can see the racing conditions were just about perfect, with minimal ice mush on the lake. Any rough patches were definitely buffered smooth by the end of the day.

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