Welcome to Minion Robot’s documentation!¶
Hardware Design¶
Electronics¶
| Motor | PWM Enable | IO Forward | IO Backward | ADC Encoder A | ADC Encoder B | ADC Current Sensor |
| NW | D3 | D30 | D32 | A11 | A10 | A8 |
| NE | D2 | D36 | D34 | A13 | A12 | A9 |
| SW | D5 | D22 | D24 | A6 | A5 | A1 |
| SE | D4 | D28 | D26 | A4 | A3 | A2 |
Block Diagram¶
This block diagram shows the electronics architechture of the Minon Robot.
Distribution Board¶
This block diagram shows the electronics architechture of the Minon Robot.
This block diagram shows the electronics architechture of the Minon Robot.
Bill of Materials¶
1. Mechanical Hardware BOM
| Sl. No. | Item | Quantity | Price | Purchase Link |
| 1 | Aluminium T-Slot Profile | 1.5m | 175/metre | |
| 2 | Cast Acrylic Sheet [300mm * 200mm] | 2 | 100 | |
| 3 | Corner Angle L Brackets | 13 | 9.18 | |
| 4 | Sliding T-Nut (M4) | 12 | 6.67 | |
| 5 | Square Nut (M4) | 18 | 2.84 | |
| 6 | Hex Nuts (M3) | 16 | 1 | |
| 7 | Bolt (M4 * 10mm) | 6 | 3.90 | |
| 8 | Bolt (M4 * 6mm) | 24 | 3.90 | |
| 9 | Bolt (M3 * 10mm) | 16 | 1 | |
| 10 | Bolt (M3 *6mm) | 90 | 1 | |
| 11 | Motor Brackets | 4 | 90 | |
| 12 | Standoffs | 30 | 1.42 | |
| 13 | Ribbon Cable | 6 | 45 | |
| 14 | Rubber Wheels | 4 | 60 |
2. Electronics BOM
| Sl. No. | Item | Quantity | Price | Purchase Link | ||
| 1 | Raspberry Pi 3 B | 1 | INR 2,726.78 | https://in.element14.com/raspberry-pi/raspberrypi3-modb-1gb/sbc-raspberry-pi-3-mod-b-1gb-ram/dp/2525225 | ||
| 2 | Arduino Mega 2360 | 1 | INR 536 | https://robu.in/product/mega-2560-atmega2560-16au-board-without-usb-cable/?gclid=Cj0KCQjwrrXtBRCKARIsAMbU6bEp9jeNAUYntCyH5mQZgtlBES8t50CTlqRcSdF8ermEJk-fCF_7tPwaAm5DEALw_wcB | ||
| 3 | Arduino Pro Mini | 1 | INR 200 | |||
| 4 | Motors | 4 | INR 2556 | |||
| 5 | Arduino Mega | 1 | INR 536 | |||
| 6 | Raspberry Pi | 1 | INR 3000 | |||
| 7 | Motor Drivers | 3 | INR 160 | |||
| 8 | Linear Actuator | 1 | INR 1777 | |||
| 9 | Decawave | 1 | INR 1775 | |||
| 10 | 12V Battery | 1 | INR 1150 | |||
| 11 | IMU 9250 | 1 | INR 430 | |||
| 12 | PCB’s | 3 | INR 28.38 | |||
| 13 | Buzzer Alarm | 1 | INR 88 | |||
| 14 | LM2596 DC-DC Buck Converter | 1 | INR 159 | |||
| 15 | Standoffs | 30 | INR 1.42 | |||
| 16 | Ribbon Cable | 6 | INR 45 | |||
| 17 | Level Converter | 1 | INR 65 | |||
| 18 | Toggle Switch | 1 | INR 20 |
| Sl. No. | Item | Quantity | Price | Purchase Link | ||
| 1 | Raspberry Pi 3 B | 1 | INR 2,726.78 | https://in.element14.com/raspberry-pi/raspberrypi3-modb-1gb/sbc-raspberry-pi-3-mod-b-1gb-ram/dp/2525225 | ||
| 2 | Arduino Mega 2360 | 1 | INR 869 | https://robu.in/product/mega-2560-atmega2560-16au-board-without-usb-cable/?gclid=Cj0KCQjwrrXtBRCKARIsAMbU6bEp9jeNAUYntCyH5mQZgtlBES8t50CTlqRcSdF8ermEJk-fCF_7tPwaAm5DEALw_wcB |
Datasheet¶
Mechanical Parameters¶
| Parameter | Value |
|---|---|
| Robot Mass | 4 kg |
| Total Length | 0.3 m |
| Total Width | 0.24 m |
| Total height | 0.26 m |
| Wheel Track | 0.22 m |
| Wheel Base | 0.18 m |
| Tire Radius | 0.035 m |
| Wheel Width | 0.02 m |
| Maximum Speed | 0.44 m/s (Without Payload) |
| Maximum Payload | 13 kg |
| Payload Ratio | 3.25 |
| Battery | Li-Ion 11.1V 4400 mAH |
Vehicle Design Parameters¶
| Vehicle Design Parameter | Value |
|---|---|
| Robot Mass (M) | 4 Kg |
| Wheel Radius(r) | 0.035m |
| Worst Working Surface | Asphalt (Cr = 0.05) |
| Number of Drive Wheels | 4 |
| Nominal Acceleration(a) | 0.1m/s^2 |
| Maximum Surface incline(𝛂) | 3 degrees |
Motor Torque Calculation¶
To choose motors capable of producing enough torque to propel the vehicle, the Total Tractive Force has to be calculated.
- Step 1: Determining Frictional Rolling Resistance
\(F_r = C_r * N\)
where,
\(Cr\) - Coefficient Of Rolling Friction
\(N\) - Normal force of wheel on the surface
- Step 2: Determining Grade Resistance
\(F_g = M * g * \sin (\alpha)\)
where,
\(M\) - Total Mass
\(G\) - Acceleration due to gravity
\(\alpha\) - Maximum Surface incline during normal operation
- Step 3: Determining Inertial Force
\(F_i = M * a\)
where,
\(a\) - Acceleration
\(M\) - Total Mass
- Step 4: Determining Total Tractive Force Required
- \(TTF = F_r + F_g + F_i\)
- Step 5: Determining Total Motor Torque
\(\text{Total Torque required} = (TTF * r) / n\)
where, \(n\) is the mechanical efficiency
Mechanical efficiency is assumed as 40% ( Due to losses due to friction in the gearbox. Four stages of gears present. Each stage of gears lead to approximately 10-15% loss)
- Step 6: Determining wheel torque
The torque required at each wheel
\[\begin{split} (T_w) &= \frac{\text{Total Torque}}{\text{Number of Drive Wheels}} \\ \\ &= \frac{\text{Total Torque}}{4}\end{split}\]