114.4.1 - Total Manufacturing

Intro to ROB MFG

“Robot” Etymology
- 1920 from Czech origin “robota” meaning ‘forced labor’, ‘servitude’, or ‘drudgery’
- The term was coined in K. Čapek's play R.U.R. ‘Rossum's Universal Robots’, attributed to his brother Josef Čapek

Unimate

First programmable Robot arm
Patented filed in 1954 by George C. Devol, Jr. & built in 1957
- PDF: US Patent # 2,988,237 - Programmed Article Transfer - G.C. Devol Jr., June 13, 1961
First Unimate ever used on an assembly line was installed at the GM plant in Trenton, NJ in 1961 to unload a die-casting press

PUMA

Programmable Universal Machine for Assembly (PUMA)
- - First 6-Axis Robot Arm (the most common/standard robot design used today)
  - Developed & released in 1978 by Victor Sheinman at Unimation for GM

It is incredibly important to understand that for most Robot programming, you do PROGRAM THE POINTS; NOT THE PATH. The robot then uses inverse kinematic algorithms to figure out the optimal path to get from point to point
- This means the path the robot takes ends up being UNPREDICTABLE, YET REPEATABLE
  - You won't know the path it takes to get from point to point, but it will take that path every time, so long as nothing in the program changes
  - For this reason, you must always "prove out" a robot's program/movements before letting it run automatically for production, to ensure it will not crash
Ultimately, robots move from point to point through coordinated, oftentimes simultaneous motion between multiple rotational/linear axes

Robots can move from point to point in a variety of different ways, but the 3 basic movement types are:
1. Point-to-Point Move
2. Linear Move
3. Arc Move

Point-to-Point (Joint) Move

Moves the robot from one waypoint to another, prioritizing joint movement efficiency over TCP path. The TCP will start and end at the programmed waypoints, but the path the robot takes will not be linear, since the fastest path with robots isn't typically a straight line.

Linear (TCP) Move

Moves the tool/TCP linearly, coming to a complete and precise stop at each programmed waypoint. This movement type is useful for when high-precision is needed for robot positioning accuracy.

Arc/Circle Move

Moves the tool in a precise, circular arc motion, that can either stop at each waypoint linearly or maintain constant speed by blending motion through points. Defined by 3 points: Start Point, Via-/Mid-Point, & End Point. With arc moves, the TCP can either stay in a fixed orientation, or it can maintain a specific orientation to the arc, throughout the arc move; it "follows the curve".

Move Blending/Smoothing

Can be applied to most move types. The tool moves linearly with constant speed, doing so by "rounding the corner" when it gets within a specified spherical radius of a programmed point, instead of stopping at each point precisely. In situations where exact positional precision is not required, move blending significantly speeds up processes.

For identifying points in 3-Dimensional space, you need a frame of reference - an origin point/plane with a specific orientation. Robots have some reference frames built-in by default, whereas others can be set/customized by the user/programmer

General Robot Safety Best Practices:

- NEVER bypass any safety measures/devices, either within the Robot, within the Robot's cell, or within the programming

Industrial Robot Safety

Cobot Safety

- Cobots CAN STILL INJURE/KILL YOU
  - Just because Cobots are intended/marketed to be used around & in conjunction with humans, doesn't mean they are not also dangerous:
    - It is extremely easy to create pinch points between a Cobot, a hard surface, and your fingers/hair/other body parts
    - DO NOT wear jewelry, baggy clothing, hanging long hair, or other items on your person that can be caught & pulled by the Cobot or it's attachments (end effectors, tubing, cabling, etc.)
    - If a Cobot has something sharp attached to it (blades, needles, etc.), the object can potentially pierce/slice your skin/body/organs without achieving sufficient enough resistance/feedback to stop the Cobot

Robot Ethics Thought Experiment #1: Military Robot “Accident”

Sniper "Dog" Robot
- - Complex vision system, programmed to identify & eliminate targets based on clothing, presence of weapons, skin color, etc.
    - What are the implications of this?
    - If the robot shoots an innocent person or “friendly”, who is responsible/liable? The Operator? The Programmer? The Robot? The Manufacturer? The Military? Taxpayers? The Engineer?

Robot Ethics Thought Experiment #2: Medical Robot “Accident”

Surgical Robot
- - Complex vision system, programmed designed to pinch off blood vessels if they rupture & cause bleeding. Incorrectly identifies a non-bleeding, key blood vessel to brain/key, pinches it off & causes the patient to die
    - What are the implications of this?
    - Who is responsible/liable? The Surgeon? The Programmer? The Robot? The Hospital?

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