Tigerbot P15201 Detailed Design Review

Mechanical

Torque Recalculations ●Added min and max in walking motion.

Servos and Motors Selection (Walking)

CAD Models (Full Assembly)

CAD Drawings Cont. (Torso)

CAD Drawings Cont. (Lower Body) Lazy Susan Hip Design

Manufacturing ●Process o Get Stock Aluminum o Square it to dimensions o Bend into U bracket o Weld rod to 2 brackets (one on each side) ●*Welding Depends on Rob Kraynik(ME Shop Machinist) schedule. Easy task to accomplish; risk: lead time

Schedule (Manufacturing)

Testing Plans ●Torque Output: o Test the servo with the gear combination for the required torque output. ●Degrees of Freedom: o Measure overall range of each joint

Electrical

Expected Power

We plan on using a fixed 48V 32A DC supply to test the design and gain an accurate measure of current draw. Our power draw estimates currently assume a 4A draw by the servos For purely walking: Ptotal=20A at 48V= 960W | ~20A For tour scenario: Pwalk= 20A at 48V = 960W | 8A Pstand= 15A at 48V= 720W | 9A Ptotal=60%Pstand+40%Pwalk=816W |~20A Based on new information, our current draw will be less than 4A. Therefore our power required will be less than the worse case, which is less than 960W. If, we were to purchase a battery, our solution would be,

Wiring ●8 AWG wire used for battery to distro board ●8 AWG wire used from power supply to distro board (in place of batteries) ●18 AWG wire used for servo power (distro to servo) ●18 AWG wire used for servo control (microcontrollers to servo) o 18 AWG chosen to fit MOLEX crimp pins for servo connections ●28 AWG ribbon cable used for sensor wiring (power, data, I2C, etc.)

Servo Connections ●MOLEX Minifir Jr. series mates with Teknic servo power/control connectors o 4 pin for power o 8 pin for control

Schematic Refer to handout please

Custom PCBs ●1 (x2) for FSR support circuitry ●1 (x1) for servo power distribution ●1 (x5) for ADC and support circuitry ●8 total Advanced Circuits offers 60 in 2 of 2 layer board space for $33 to students

Sensors Force Sensing Resistor (FSR): FlexiForce Sensors: A201- Connector 3-pin male square pin Weight Range: 0-1 lb (4.4 N) 0-25 lb (110 N) lb (440 N)** **Weight range can be increased with the proper circuit layout We used the recommended circuit in the spec sheet and modified it

Sensor

From the manufacturer

Sensor RFID: At this time we have decided to not choose a RFID solution. Due to the scope of our project a RFID solution will be generated if there is time available.

Sensor Object Detection: Parallax Ping Ultrasonic and Sharp IR: We plan to use a combination of sensors for object detection in the path of the robot. Ultrasonic will provide long range and IR will provide close range detection.

Sensor Sharp IR Distance Sensor - GP2D12 Alternative Connector: 3 pin with analog output Detection: 10-80cm. Will require additional cable

Sensor Parallax Ping Ultrasonic: One of two options we are testing. Connection: 3 pin bidirectional TTL Detection: 0.02 to 3 m Concern: Based on testing, it may not have a fast enough response time. We are considering alternatives.

Sensor 25k Potentiometer Use as simple position feedback for the servos

ItemPartDescriptionLink/Manufacturer Unit Price Quantit y Extended Price E1Wired PSU 48VDC 32A servo power supplyhttp:// L2Pololu 5V PSU5V regulated PSUhttp:// E3Pololu 3.3V PSU3.3V regulated PSUhttp:// C4 3M 3365/20 20COND, 100FT, 28AWG, 300VRibbon Cable 28awg/dp/03F5908$ T5ADC128D81812-bit ADC detail/en/ADC128D818CIMT%2FNOPB/ADC128D818CIMT%2FNOP B-ND/ $5.905$29.50 R6 Custom Li-Ion Battery: 7.4V 6.6Ah LiPo Battery for Sensors wh-battery-module-with-pcb.aspx$ I7 HIGH C-RATE LIPO BATTERY LiPo Battery for Servos lifepo4-battery-12-cells-ebike-battery-pack.html$ $ C825k PotPotentiometerhttp:// A9Parallax PING)))Ultrasonic Sensor Documentation-v1.6.pdf$ L10 GP2D12 Alternative (10-80 cm)*Sharp IR Sensor gp2d12.aspx$12.956$ Dev. boardRFID ND/ $ FlexiForce Sensors: A201 Force Sense Resistorhttp:// 13Teensy MicroMicrocontrollerhttps://

14 Micro USB-USB 2.0 Sync Data Charge CableWire =9SIA1UA1UH3571&cm_re=micro_usb_to_usb-_- 9SIA1UA1UH3571-_-Product$0.9810$ AWGWire red-black-zip-power-speaker-wire-1-ft-usa $ $ pin MOLEX connectorservo power connector search/en?x=0&y=0&lang=en&site=us&keywords= $0.3123$ pin MOLEX connectorservo control connector search/en?KeyWords= &WT.z_header=se arch_go$0.4523$ MOLEX crimp pinservo crimp pin detail/en/ /WM2501CT-ND/467978$ $ A screw terminal power distro screw terminal detail/en/8196/8196K-ND/316832$0.794$ AWGWire high-current-power-cable-1-ft-usa $0.9525$ StarTech ST7202USB7 Port USB 2.0 Hub =9SIA24G &cm_re=usb_hubs_powered-_ _-Product$ ft 12 AWG 3 conductor wirePower wire sjoow-power-cable-50-ft $ A industrial AC plugPower connector Amp-125-Volt-Industrial-Grade-Straight-Plug- PS5266XCCV4/ $ TL074General Purpose Op-Amphttp:// 25IC Sockets14 pin IC socket HZL-TT-R/AE10012-ND/821766$0.792$1.58

26Resistors1kOhm 0.25Whttp:// 27Resistors4kOhm 0.25Whttp:// 28Resistors10kOhm 0.25Whttp:// 29Bypass CapacitorTantalum, 0.1 uf -1uf-35v-radial-tantalum-capacitor.html$0.1110$ Bypass CapacitorCeramic, 0.1 ufhttps://

UPDATE:

Computer

Pandaboard

ROS for a Leg

Message Passing

ROS Stack

ROS Nodes

I2C - working! IMU - interfaced and reading data ROS - learned much, but still much to learn Simulation - learning ros, we have simple moving models working. Simulation - Currently working on interfacing controls, this will be applied to tigerbot when more is learned. Online teensy programming - works manually, working on automated script ROS intro tutorial - DONE! Teknic motor control update - Pulse Burst Positioning appears to be the best control method, the desired distance (rotation) is proportional to the number of pulses sent to the motor. 2 velocities can be preprogrammed. Work on ROS / CPU / Sim status

Questions?