Tom and Jerry - Solar “Tom” catches RC “Jerry”

Team members: 1. Sander Vocke 2. Sethuraman J 3. Jumana MP 4. Praveen Pujari

Goals

• A Solar powered car – TOM that follows a small RC car –JERRY and tries to catch it!

• Visual tracking of the moving RC car and try interception. Servo-mounted camera or stationary “omni-camera”

• Probably weak magnets attached to both cars in order to perform the “catch”

Block Diagram : servo-mounted cam

Excluded: various voltage regulators may be necessary

Indicative: design of robot

• Two powered wheels, one freely rotating caster wheel: small turning circle.

• Target RC car encased in a

spherical, colored housing, to make detection manageable

• Most surface area of robot dedicated to solar panels

• Use typical hobby supplies to construct our own large, flat light-weight chassis

Alternative vision: 360 degree omni-cam

Example: http://www.kscottz.com/dewarped-panoramic-images-from-a-raspberrypi-camera-module/

(includes sample video of warped and de-warped 360deg image from raspberry camera) - uses Kogeto Dot lens (Iphone design)

- blurry, but adequate video.

- Lightweight lens with small form-factor

Alternative vision: 360 degree omni-cam

Another way: point camera at a spherical mirror:

Example:

https://www.youtube.com/watch?v=z7SwpT9ymb4

- Typically stainless steel – heavy! And blocks the sun…

mirror

BubbleScope 360 degree lens

• Better vertical range and quality than Kogeto Dot and Gopano Micro

• ~35 euros (order from UK)

• Has also been tinkered onto a RasPi before: https://www.youtube.com/watch?v=EecfGJCjog0 (note the sharpness and range, though lens=dirty)

• Small, lightweight, relatively easy to mount.

Alternative vision: 360 degree omni-cam

- Lower power: no moving servo parts

- More awareness: simultaneous view of “everything”

- We e-mailed the builder of the spherical mirror ESCALADE360 robot. He mentioned they didn’t de-warp the image but instead processed the circular image directly to do object detection.

Processing

• Raspberry Pi 2 board: quad-core ARM CPU with Broadcom GPU

• Many possibilities for parallel visual processing: multi-core code and GPU through OpenGL ES interface

• Cheap (<40$), low-power (<2W), many interfacing options and GPIOs, much community support for quick development

MPPT for solar panels

• No off-the-shelf solution available for high-current solar LiPo charging

• Design custom PCB using TI BQ24650 MPPT battery charger IC, which offers external switches/inductor and programmable current settings.

Battery

• 3.7V LiPo single cell battery.

• Low-capacity version for final version (650mAh), high-capacity version for testing (2200mAh, 5000mAh)

• Need a boost converter board for getting 5V to Raspberry Pi, DC motors, possibly a motor controller.

Current Status

• Waiting for the final approval of components from instructors

• Order the components as soon as possible

• Literature survey for control and video processing!

Components list S.No. COMPONENTS SPEC COST Link

1 Raspberry pi 2 B

900 Mhz, 1GB LPDDR2, ARM v7 €45.00

http://www.kiwi-electronics.nl/raspberry-pi-2-model-b-1gb

2 Pi onchip camera

5 Mp, 2592*1944, 30 frames/s €30.00

http://www.kiwi-electronics.nl/raspberry-pi-camera-module?search=pi%20camera

3

Servo motor for camera

9g micro-servo, hobbyking, 0.6kg €2.32

http://www.hobbyking.com/hobbyking/store/__663__HXT500_6_2g_0_6kg_08sec_Micro_Servo.html

4

DC Geared motors (2) + Motor controller

DC Motor-25 6V/185RPM €32.00

http://www.makeblock.cc/dc-motor-25-6v-185rpm/ http://www.robotshop.com/en/dagu-4-channel-brushed-dc-motor-controller.html

5

Lipo Battery High capacity for testing

5000mAh round cell @ 40C charge rate €11.49

http://www.hobbyking.com/hobbyking/store/__18562__Turnigy_5000mAh_1S_40C_Lipoly_Single_Cell_.html

S.No. COMPONENTS SPEC COST Link

6

Lipo Battery Low capacity for car (two versions: 2200mAh and 650mAh)

2200mAh flat cell @ 20C discharge rate, 2C charge rate 650mAh round cell @ 15C discharge rate, 5C charge rate €5.74

http://www.hobbyking.com/hobbyking/store/__18558__Turnigy_2200mAh_1S_20C_Lipoly_Single_Cell_.html http://www.hobbyking.com/hobbyking/store/__23317__Turnigy_nano_tech_650mAh_1S_15c_Round_Cell.html

7 Battery charger 100-500mAh €2.22

http://www.hobbyking.com/hobbyking/store/__60568__100_500mah_LiPoly_or_LiIon_1_Cell_Micro_USB_Charger_RU_Warehouse_.html

8 Three wheels

According to the size of the chassis

€10.00

hobby shop name mentioned by Mark

9 Two caster wheels hobby shop name mentioned by Mark

10 Styrofoam plate for solar cell mounting €5.00 hobby shop name mentioned by Mark

11 MPPT BQ24650 + Adapter €3.00 Circuit building

Components list

S.No. COMPONENTS SPEC COST Link

12 RC tiny little car to buy at hobby shop, tiny €20.00 Easily visible mini sized car to chase

13 Chassis board (wood plate) to buy at hobby shop

hobby shop name mentioned by Mark

14 Voltage regulator DC-DC 3.7v to 5v Boost converter €6.92

http://www.miniinthebox.com/nl/lm2587-high-power-dc-dc-3-5-30v-boost-converter-module_p905577.html

15 Misc items for building

Wires, connectors, pliers, foam €25.00 from hobby shops

16 BubbleScope 360 degree lens from UK, Ebay €40.00

http://store.bubblepix.com/uk/bubblescope-1.html

17 Solar cells left-over from Solar Team

12x4cm 25% eff.stable cells €60.00

18 GRAND TOTAL €298.69

Components list