P08205: RP 1 Motor Module First Generation
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Electronics

Table of Contents

Electronics Introduction

The electronics subsystem was tasked with making all of the electrical systems on the RP1 work together. This includes determining how to power all electronic devices in the system, and how to route all signals/data to their proper locations. The following high level layout was determined to denote the location of all important devices, and the general interaction between them:

public/ElectronicsFiles/Sr Design - Electronics Flow Chart.png

Subsystem Team

Bryan Jimenez
Jonathan Maglaty

Concept Selection

Three concepts were proposed: Everything except the Motor Controllers (H-Bridges) on the platform, Everything on the platform (including Motor Controllers) or Everything on the Motor Module. The RP10 Redesign team (P08201) used the first option, and as such, the concept selection was labeled as that. The concept selection Pugh diagrams are below:

Screening Pugh

Selection Pugh

Bill of Materials

Detailed Bill of Materials (BOM) for the electronics subsystem can be found here.

Final Design Decisions

H-Bridge

The PWM Motor Controller 3A from SuperDroidRobots.com was selected as the best possible H-Bridge choice. This component was tested with the microprocessor and motors with success.

Concept Selection

H-Bridge

Batteries

24 volt batteries were chosen since the motors run at 24 volts.

Battery Info

Battery Selection

Current Power Distribution Design

Two DC Bucks are required to bring the 24 volt batteries down to 9 volts (for the microprocessor) and 5 volts (for the encoders). The schematics and simulations of them are below. For the simulations, the blue line is the output voltage.

DC Buck 5 Volt: |LT-Spice Schematic| |Image| |Simulation|

DC Buck 9 Volt: |LT-Spice Schematic| |Image| |Simulation|

Encoders Chosen

The encoders chosen were from US Digital - The E5 for the drive system, and the EM1 and HUBDISK combination for the steering. The HUBDISK has a mounting ring to fit securely over the cylinder that will be connected to the lower turntable, allowing 1:1 correspondence with the turning angle.

E5 Info

EM1 Info

Hubdisk Info

Link to Detailed Design Review, containing information about Electronics Subsystem choices, images of the parts/designs, etc...

Design Files

Here are all the design files for the RP1 motor module Electronics Subsystem:

Folder Link