Page 35 - Toucpad robotics C11

Example: Before building a robotic arm for factory assembly, engineers use CAD to model its links, joints, and motors.
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They then simulate its movements to ensure it can precisely pick up a part, avoid obstacles in the workspace, and
place it accurately, all within the required speed and force limits. If the simulation shows it might collide with another
machine, the design can be quickly adjusted without any material waste.
Precision Manufacturing: Bringing Digital Designs to Physical Reality

Once the design is perfected in the CAD environment, the next step is to physically create the robot’s components. This
requires precision manufacturing techniques, which ensure that parts are made to extremely tight tolerances and exact
specifications. The performance of a robot’s sensors, actuators, and control units is directly dependent on the accuracy
of their manufacturing.

Manufacturing of Mechanical Components (Structure and Actuators)
CNC Machining (Computer Numerical Control): This is a widely used method where computer-controlled machines
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(like mills and lathes) precisely cut, drill, and shape materials (metals, plastics) according to the CAD model. It’s
essential for creating complex parts like gears, motor housings, and robot arm links with high accuracy.
Example: The intricate gears inside a robot’s joint, which allow for precise movement, are typically manufactured
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using CNC machining to ensure minimal “backlash” (play or looseness) and smooth operation.
3D Printing (Additive Manufacturing): For rapid prototyping, complex geometries, or lightweight components, 3D
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printing (using various materials like plastics, resins, or even metals) is increasingly used. It builds parts layer by layer
directly from the CAD model.
Example: A complex custom gripper for a specific object, with internal channels for vacuum, could be 3D printed,
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allowing for designs impossible with traditional manufacturing.
Moulding and Casting: For high-volume production of specific plastic or metal parts, moulding (e.g., injection
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moulding for plastic housings) or casting techniques might be used.

Creation of Sensors
Sensors are often micro-scale devices and require highly specialised manufacturing processes.
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Micro-Electro-Mechanical Systems (MEMS) Technology: Many modern sensors (like accelerometers, gyroscopes,
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some pressure sensors) are built using MEMS technology. This involves fabricating tiny mechanical structures on
silicon wafers using techniques similar to those for making computer chips (e.g., photolithography, etching).
Example: The tiny components inside your smartphone’s accelerometer, which detects its orientation, are
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manufactured using MEMS technology, allowing for incredibly small and precise sensors.
Optics and Lenses: For vision-based sensors (cameras, Lidar), precision optics are crucial. Lenses and mirrors are
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manufactured with extremely fine tolerances to ensure clear and accurate image capture.
Material Deposition and Etching: For various sensor types, thin films of specific materials (e.g., resistive materials
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for touch sensors, or light-sensitive materials for photo-sensors) are precisely deposited and etched onto substrates.
Impact of Precision: Any imperfection in sensor manufacturing can lead to inaccurate readings, causing the robot to
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misinterpret its environment and make incorrect decisions. Precision ensures reliability and sensitivity.

Fabrication of Control Units (PCBs and Processors)

u The robot’s ‘brain’ – its control unit – is typically a Printed Circuit Board (PCB) populated with microprocessors,
memory chips, and other electronic components.

u PCB Manufacturing: PCBs are created by precisely etching conductive copper traces onto a non-conductive
substrate. Multiple layers are common for complex designs.
u Component Mounting (Surface-Mount Technology - SMT): Tiny electronic components (like resistors, capacitors,
and the microprocessors themselves) are precisely placed and soldered onto the PCB using automated pick-and-
place machines. This requires extreme precision to avoid short circuits or poor connections.

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Introduction to Robots: What Exactly are They?