Tigerbot P15201 Detailed Design Review. Mechanical.

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

● Processo Get Stock Aluminumo Square it to dimensionso Bend into U bracketo 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

Expected PowerWe 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 | ~20AFor 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 powero 8 pin for control

SchematicRefer 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 in2 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)

0-100 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

Sensor

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

Item Part Description Link/ManufacturerUnit Price

Quantity

Extended Price

E 1 Wired PSU48VDC 32A servo

power supply http://www.trcelectronics.com/View/Mean-Well/RSP-1500-48.shtml $348.30 1 $348.30

L 2 Pololu 5V PSU 5V regulated PSU http://www.pololu.com/product/2851 $14.95 1 $14.95

E 3 Pololu 3.3V PSU 3.3V regulated PSU http://www.pololu.com/product/2110 $14.95 1 $14.95

C 43M 3365/20 20COND, 100FT, 28AWG, 300V Ribbon Cable http://www.newark.com/3m/3365-20/cable-ribbon-20cond-100ft-28aw

g/dp/03F5908$35.80 1 $35.80

T 5 ADC128D818 12-bit ADC http://www.digikey.com/product-detail/en/ADC128D818CIMT%2FNOPB/ADC128D818CIMT%2FNOPB-ND/2262897

$5.90 5 $29.50

R 6Custom Li-Ion Battery:

7.4V 6.6AhLiPo Battery for

Sensors http://www.batteryspace.com/custom-li-ion-battery-7.4-v-6600-mah-44.84-wh-battery-module-with-pcb.aspx

$58.90 1 $58.90

I 7HIGH C-RATE LIPO

BATTERYLiPo Battery for

Servos http://www.bmsbattery.com/battery-pack/664-36v-12ah-38140-lifepo4-battery-12-cells-ebike-battery-pack.html

$219.00 2 $438.00

C 8 25k Pot Potentiometer http://www.smallbearelec.com/servlet/Detail?no=688 $1.00 22 $22.00

A 9 Parallax PING))) Ultrasonic Sensor http://www.parallax.com/sites/default/files/downloads/28015-PING-Documentation-v1.6.pdf

$29.99 1 $29.99

L 10GP2D12 Alternative

(10-80 cm)* Sharp IR Sensor http://www.trossenrobotics.com/sharp-ir-distance-sensor-gp2d12.aspx

$12.95 6 $77.70

11 Dev. board RFID http://www.digikey.com/product-detail/en/TRF7970ATB/296-31310-ND/2833503

$50.00 1 $50.00

12FlexiForce Sensors:

A201Force Sense

Resistor http://www.tekscan.com/flexible-force-sensors $117.00 1 $117.00

13 Teensy Micro Microcontroller https://www.pjrc.com/teensy/ $15.95 5 $79.75

14Micro USB-USB 2.0 Sync Data Charge Cable Wire http://www.newegg.com/Product/Product.aspx?Item

=9SIA1UA1UH3571&cm_re=micro_usb_to_usb-_-9SIA1UA1UH3571-_-Product

$0.98 10 $9.80

15 18AWG Wire https://www.parts-express.com/jsc-wire-18-awg-red-black-zip-power-speaker-wire-1-ft-usa--100-050

$0.31 340 $105.40

16 4 pin MOLEX connector servo power connector http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&keywords=39012040

$0.31 23 $7.13

17 8 pin MOLEX connector servo control connector http://www.digikey.com/product-search/en?KeyWords=39012080&WT.z_header=search_go

$0.45 23 $10.35

18 MOLEX crimp pin servo crimp pin http://www.digikey.com/product-detail/en/0039000038/WM2501CT-ND/467978

$0.10 300 $30.00

19 30A screw terminalpower distro screw

terminal http://www.digikey.com/product-detail/en/8196/8196K-ND/316832

$0.79 4 $3.16

20 8 AWG Wire https://www.parts-express.com/jsc-wire-8-awg-red-high-current-power-cable-1-ft-usa--100-178

$0.95 25 $23.75

21 StarTech ST7202USB 7 Port USB 2.0 Hub http://www.newegg.com/Product/Product.aspx?Item=9SIA24G2179518&cm_re=usb_hubs_powered-_-17-707-143-_-Product

$19.41 1 $19.41

22 50ft 12 AWG 3 conductor wire Power wire https://www.parts-express.com/carol-12-awg-3c-sjoow-power-cable-50-ft--100-578

$51.01 1 $51.01

23 15A industrial AC plug Power connector http://www.homedepot.com/p/Pass-Seymour-15-Amp-125-Volt-Industrial-Grade-Straight-Plug-PS5266XCCV4/202664475

$8.68 1 $8.68

24 TL074 General Purpose Op-Amp http://www.ti.com/product/TL074/description $0.69 2 $1.38

25 IC Sockets 14 pin IC socket http://www.digikey.com/product-detail/en/AR14-HZL-TT-R/AE10012-ND/821766

$0.79 2 $1.58

26 Resistors 1kOhm 0.25W http://www.circuitspecialists.com/rc1000.html $0.10 16 $1.60

27 Resistors 4kOhm 0.25W http://www.circuitspecialists.com/rc4020.html $0.10 8 $0.80

28 Resistors 10kOhm 0.25W http://www.circuitspecialists.com/rc10k.html $0.10 20 $2.00

29 Bypass Capacitor Tantalum, 0.1 uf http://www.taydaelectronics.com/capacitors/0-1uf-35v-radial-tantalum-capacitor.html

$0.11 10 $1.10

30 Bypass Capacitor Ceramic, 0.1 uf https://www.sparkfun.com/products/8375 $0.25 10 $2.50

UPDATE:

Computer

Pandaboard

ROS for a Leg

Message Passing

ROS Stack

ROS Nodes

I2C - working!IMU - interfaced and reading dataROS - learned much, but still much to learnSimulation - 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?