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Prototype #1 - Test Plan

Prototype #1 - Test Plan

Jul 13, 2021

Tasks

See Prototype Definitions Page for more info (some content pulled from this page)

 

Main elements to test (In order):

  1. Speed and acceleration :

    1. Find the ideal joint speeds and accelerations for each joint

  2. Test workspace (no load):

    1. Determine arm mobility

    2. Find the arm positions we are likely to see in the field

    3. Assess accuracy and repeatability of the arm (not mandatory)

  3. Test the torque at each joint (with and without load):

    1. Measure the torque at anticipated joint speeds, accelerations and workspace extremes 

 

Torque/Speed:

Measure torque at each joint (During assembly to ensure roughly correct torque is provided)
Measure max torque at each joint
Determine a more suitable safety factor based on recorded torque
Determine refined linkage lengths (if applicable)
Determine approximate ideal RPM for each joint
Time Permitting - Data set of joint torques (on average) for all expected arm calcs

Competition Tasks:

Retrieval and Delivery

Lifting Payload (5kg payload, rope tow) 
Pick something off the ground (5 cm diameter) → Screw driver?
Pull an object by a rope

Equipment Servicing 

Lift from handle (10cm long, 5cm diameter)
Open a drawer → There's one for testing in the bay already
Flip a switch → I think there's one for testing in the bay already
Turn a knob → I think there's one for testing in the bay already
Use of Allen key
Use a keyboard → We have one in the bay already and this would be a good opportunity to test the precision of the arm
Operate joystick 
Insert USB type A into slot

Deliverables

Max Torque for each joint (with load)
Refined safety factor
Refined linkage lengths
Ideal RPMs for each joint
Idea accelerations for each joint
Refined workspace
Weight (Is this relevant? Will the change in components make this obsolete?) 

Procedures

3. Measuring Torque

Each step is done twice for each joint (with and without load)

3.1 Measure Power - Voltage

  1. Plug black wire into ground on multimeter

  2. Plug red wire into volts on multimeter

  3. Turn dial on voltmeter so that it is referring to appropriate voltage measurement

3.2 Measure Power - Current

  1. Plug in black wire into ground on multimeter

  2. Plug red wire into amps on multimeter

  3. Turn dial so it is on the Amperage measurement

  4. Put multimeter in series with motor/power supply

3.3 Measure Speed - Encoder

  1. Record RPMs from encoders

3.4 Calculate Torque

  1. Calculate torque using the following equations

2. Record here

 

Interesting Method

Came across this video and was curious. Isn't really a viable method for us

See method here

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