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Petter’s Robot dreams » Segway. Embedded by Embedded Video YouTube Direkt Why build a DIY Segway?

Petter’s Robot dreams » Segway

The main reason that I wanted to build a DIY Segway was simply because I wanted to see if it was possible. I also liked the idea of building something that strongly interacts with humans. I will now describe how I built it. Hardware The motors, wheels, chain, gears and batteries came from electric scooters like the one to the right. The gearing is made in one step from the small gear on the motor to the bigger gear head on the wheel. The fasting of the gear on the 12” wheel was based on a freewheel mechanism therefore I had to open up the freewheel and remove all the grease and then use epoxy to make it possible to drive it in both directions.

There is one fixed axle on which both wheels rotate, this axle is attached with three aluminum blocks which fixates the axle with 5mm set screws. The handlebar is a normal bicycle handlebar, the pipe on which it is connected is a 25mm hollow steel pipe. Electronics Software Cost. TILTO. The next step was to start writing the software.

TILTO

For that I studied tons of simmilar projects and had to refresh my coding competence. I had also to update all the software used to write, compile, simulate, etc., and practically had to learn again to use embedded microprocessors. The result was a long piece of software, coded in C for a 16F877 microprocesor from the PIC family (they are obsolete, but I had a couple in an old drawer...). I disregarded the Kalman Filter in favor of Complementary Filters to fusion the accelerators and gyroscopes data, to get the actual tilting angles, free from noise (kind of).

Then a PID (Proportional, Integral, Derivative) algorithm produce the PWM (Pulse Width Modulation) signals to be sent to the motor drivers. When the software was ready enough I bought a 5 degree of freedom (3 accelerometers + 2 gyros) IMU (Inertial Measurement unit) and mounted it together with the microprocessor on a crappy brown perf board, as can be seen in the videos:

Balancing Robot. HI guys, This is Balance1, my balancing robot, I built balance1 to demonstrate that a digital controller I had designed in MatLab actually worked in the real world.

Balancing Robot

The controller i ended up using for Balance1 is a digital LQR controller to balance and also stay in the same position. The LQR controller works really well because it uses a weigthing matrix to let you make balancing more important than staying in the same position. This means that if Balance1 is going to fall over then it doesn't worry much about its position it just consentrates on balancing, then when its more balanced it tries to get back to its starting position. Robot Body: The frame is made from 15mm aluminium angle amd 3mm clear perspex Most of the hardware is held inside black plastic project boxes Hardware Used: Further Work: Equals zero. Segway wheel chair. Projekt SEGI. Die reinen Materialkosten, für den fertigen SEGI, belaufen sich auf ca. € 1000,- Nicht dazugerechnet ist die Entwicklung, Prototypenbau und die Arbeitszeit.

Projekt SEGI

Endstufe, Prozessorplatine und Konstantstromquelle wurden 3mal aufgebaut. (erster Aufbau für Prototyp, zweiter Aufbau für Vortest, dritter Aufbau für Prüfung) Technische Daten: Versorgung : 4 Bleigel Akkus mit insgesamt 24V/14Ah ( halten aber auf Dauer, den Spitzenstrom von 40 Ampere nicht aus ) Größe : 700mm Breite, 540mm Länge, 1270mm Höhe. ( Lenkstange demontiert = 420mm Höhe ) Reifen : 390mm * 110mm Gewicht : 42kg (mit 4 Bleigel Akkus) Reichweite : noch nicht getestet Geschwindigkeit : noch nicht gemessen, aber dürften sicher so 20km/h drinnen sein.

Bevor Anfragen kommen: Das Projekt wird nicht in Serie gehen und es ist auch nicht zu verkaufen! Grund: Die Unfallgefahr ist für einen Verkauf zu groß. Ich suchte eigentlich nur nach einem Meisterstück-Projekt und angesteckt durch das Segway-Fieber ergabt sich dieses tolle SEGI-Projekt. Inspired by segway™ - making a self-balancing 2 wheel vehicle.